Merge pull request #7242 from reasonerjt/oidc-controllers

Add controller to handle oidc login

src/Gopkg.lock

@@ -100,6 +100,14 @@
   revision = "542e16cac74562eefac970a7d0d1467640d1f1cb"
   version = "v1.7.0"
 
+[[projects]]
+  digest = "1:f6e5e1bc64c2908167e6aa9a1fe0c084d515132a1c63ad5b6c84036aa06dc0c1"
+  name = "github.com/coreos/go-oidc"
+  packages = ["."]
+  pruneopts = "UT"
+  revision = "1180514eaf4d9f38d0d19eef639a1d695e066e72"
+  version = "v2.0.0"
+
 [[projects]]
   digest = "1:a2c1d0e43bd3baaa071d1b9ed72c27d78169b2b269f71c105ac4ba34b1be4a39"
   name = "github.com/davecgh/go-spew"
@@ -404,6 +412,17 @@
   revision = "792786c7400a136282c1664665ae0a8db921c6c2"
   version = "v1.0.0"
 
+[[projects]]
+  branch = "master"
+  digest = "1:bd9efe4e0b0f768302a1e2f0c22458149278de533e521206e5ddc71848c269a0"
+  name = "github.com/pquerna/cachecontrol"
+  packages = [
+    ".",
+    "cacheobject",
+  ]
+  pruneopts = "UT"
+  revision = "1555304b9b35fdd2b425bccf1a5613677705e7d0"
+
 [[projects]]
   digest = "1:3f68283c56d93b885f33c679708079e834815138649e9f59ffbc572c2993e0f8"
   name = "github.com/robfig/cron"
@@ -433,10 +452,12 @@
   version = "v1.2.0"
 
 [[projects]]
-  digest = "1:9c94d918a2ac65f60d6b7895b2e9612e4554b40ee2446f2f807cadb3e57da7e2"
+  digest = "1:ab3259b9f5008a18ff8c1cc34623eccce354f3a9faf5b409983cd6717d64b40b"
   name = "golang.org/x/crypto"
   packages = [
     "cast5",
+    "ed25519",
+    "ed25519/internal/edwards25519",
     "openpgp",
     "openpgp/armor",
     "openpgp/clearsign",
@@ -529,6 +550,18 @@
   revision = "8168ee085ee43257585e50c6441aadf54ecb2c9f"
   version = "v2.5.0"
 
+[[projects]]
+  digest = "1:c0c30f47f9c16f227ba82f0bdfd14fa968453c30b7677a07903b3b4f34b98d49"
+  name = "gopkg.in/square/go-jose.v2"
+  packages = [
+    ".",
+    "cipher",
+    "json",
+  ]
+  pruneopts = "UT"
+  revision = "628223f44a71f715d2881ea69afc795a1e9c01be"
+  version = "v2.3.0"
+
 [[projects]]
   digest = "1:2a81c6e126d36ad027328cffaa4888fc3be40f09dc48028d1f93705b718130b9"
   name = "gopkg.in/yaml.v2"
@@ -685,6 +718,7 @@
     "github.com/casbin/casbin/model",
     "github.com/casbin/casbin/persist",
     "github.com/casbin/casbin/util",
+    "github.com/coreos/go-oidc",
     "github.com/dghubble/sling",
     "github.com/dgrijalva/jwt-go",
     "github.com/docker/distribution",

src/Gopkg.toml

@@ -112,6 +112,10 @@ ignored = ["github.com/goharbor/harbor/tests*"]
   name = "github.com/robfig/cron"
   version = "=1.0"
 
+[[constraint]]
+  name = "github.com/coreos/go-oidc"
+  version = "=2.0.0"
+
 [[constraint]]
   name = "gopkg.in/yaml.v2"
   version = "=2.1.1"

src/common/config/manager.go

@@ -17,6 +17,7 @@ package config
 import (
 	"fmt"
 	"os"
+	"sync"
 
 	"github.com/goharbor/harbor/src/common"
 	"github.com/goharbor/harbor/src/common/config/metadata"
@@ -52,6 +53,7 @@ func NewRESTCfgManager(configURL, secret string) *CfgManager {
 
 // InMemoryDriver driver for unit testing
 type InMemoryDriver struct {
+	sync.Mutex
 	cfgMap map[string]interface{}
 }
 
@@ -59,11 +61,19 @@ type InMemoryDriver struct {
 // it should be invoked before get any user scope config
 // for system scope config, because it is immutable, no need to call this method
 func (d *InMemoryDriver) Load() (map[string]interface{}, error) {
-	return d.cfgMap, nil
+	d.Lock()
+	defer d.Unlock()
+	res := make(map[string]interface{})
+	for k, v := range d.cfgMap {
+		res[k] = v
+	}
+	return res, nil
 }
 
 // Save only save user config setting to driver, for example: database, REST
 func (d *InMemoryDriver) Save(cfg map[string]interface{}) error {
+	d.Lock()
+	defer d.Unlock()
 	for k, v := range cfg {
 		d.cfgMap[k] = v
 	}

src/common/config/metadata/type.go

@@ -61,11 +61,11 @@ type AuthModeType struct {
 }
 
 func (t *AuthModeType) validate(str string) error {
-	if str == common.LDAPAuth || str == common.DBAuth || str == common.UAAAuth || str == common.HTTPAuth {
+	if str == common.LDAPAuth || str == common.DBAuth || str == common.UAAAuth || str == common.HTTPAuth || str == common.OIDCAuth {
 		return nil
 	}
-	return fmt.Errorf("invalid %s, shoud be one of %s, %s, %s, %s",
+	return fmt.Errorf("invalid %s, shoud be one of %s, %s, %s, %s, %s",
-		common.AUTHMode, common.DBAuth, common.LDAPAuth, common.UAAAuth, common.HTTPAuth)
+		common.AUTHMode, common.DBAuth, common.LDAPAuth, common.UAAAuth, common.HTTPAuth, common.OIDCAuth)
 }
 
 // ProjectCreationRestrictionType ...

src/common/utils/oidc/helper.go

@@ -0,0 +1,131 @@
+// Copyright 2018 Project Harbor Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//    http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package oidc
+
+import (
+	"context"
+	"fmt"
+	gooidc "github.com/coreos/go-oidc"
+	"github.com/goharbor/harbor/src/common/models"
+	"github.com/goharbor/harbor/src/common/utils/log"
+	"github.com/goharbor/harbor/src/core/config"
+	"golang.org/x/oauth2"
+	"strings"
+	"sync"
+	"sync/atomic"
+	"time"
+)
+
+const googleEndpoint = "https://accounts.google.com"
+
+type providerHelper struct {
+	sync.Mutex
+	ep       atomic.Value
+	instance atomic.Value
+	setting  atomic.Value
+}
+
+func (p *providerHelper) get() (*gooidc.Provider, error) {
+	if p.instance.Load() != nil {
+		if p.ep.Load().(string) != p.setting.Load().(models.OIDCSetting).Endpoint {
+			if err := p.create(); err != nil {
+				return nil, err
+			}
+		}
+	} else {
+		p.Lock()
+		defer p.Unlock()
+		if p.instance.Load() == nil {
+			if err := p.loadConf(); err != nil {
+				return nil, err
+			}
+			if err := p.create(); err != nil {
+				return nil, err
+			}
+			go func() {
+				for {
+					if err := p.loadConf(); err != nil {
+						log.Warningf(err.Error())
+					}
+					time.Sleep(3 * time.Second)
+				}
+			}()
+		}
+	}
+
+	return p.instance.Load().(*gooidc.Provider), nil
+
+}
+
+func (p *providerHelper) loadConf() error {
+	var c *models.OIDCSetting
+	c, err := config.OIDCSetting()
+	if err != nil {
+		return fmt.Errorf("failed to load OIDC setting: %v", err)
+	}
+	p.setting.Store(*c)
+	return nil
+}
+
+func (p *providerHelper) create() error {
+	bc := context.Background()
+	s := p.setting.Load().(models.OIDCSetting)
+	provider, err := gooidc.NewProvider(bc, s.Endpoint)
+	if err != nil {
+		return err
+	}
+	p.ep.Store(s.Endpoint)
+	p.instance.Store(provider)
+	return nil
+}
+
+var provider = &providerHelper{}
+
+func getOauthConf() (*oauth2.Config, error) {
+	p, err := provider.get()
+	if err != nil {
+		return nil, err
+	}
+	setting := provider.setting.Load().(models.OIDCSetting)
+	scopes := []string{}
+	for _, sc := range setting.Scope {
+		if strings.HasPrefix(p.Endpoint().AuthURL, googleEndpoint) && sc == gooidc.ScopeOfflineAccess {
+			log.Warningf("Dropped unsupported scope: %s ", sc)
+			continue
+		}
+		scopes = append(scopes, sc)
+	}
+	return &oauth2.Config{
+		ClientID:     setting.ClientID,
+		ClientSecret: setting.ClientSecret,
+		Scopes:       scopes,
+		RedirectURL:  setting.RedirectURL,
+		Endpoint:     p.Endpoint(),
+	}, nil
+}
+
+// AuthCodeURL returns the URL for OIDC provider's consent page.  The state should be verified when user is redirected
+// back to Harbor.
+func AuthCodeURL(state string) (string, error) {
+	conf, err := getOauthConf()
+	if err != nil {
+		log.Errorf("Failed to get OAuth configuration, error: %v", err)
+		return "", err
+	}
+	if strings.HasPrefix(conf.Endpoint.AuthURL, googleEndpoint) {
+		return conf.AuthCodeURL(state, oauth2.AccessTypeOffline), nil
+	}
+	return conf.AuthCodeURL(state), nil
+}

src/common/utils/oidc/helper_test.go

@@ -0,0 +1,99 @@
+// Copyright 2018 Project Harbor Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//    http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package oidc
+
+import (
+	"github.com/goharbor/harbor/src/common"
+	"github.com/goharbor/harbor/src/common/models"
+	"github.com/goharbor/harbor/src/core/config"
+	"github.com/stretchr/testify/assert"
+	"net/url"
+	"os"
+	"strings"
+	"testing"
+	"time"
+)
+
+func TestMain(m *testing.M) {
+	conf := map[string]interface{}{
+		common.OIDCName:           "test",
+		common.OIDCEndpoint:       "https://accounts.google.com",
+		common.OIDCSkipCertVerify: "false",
+		common.OIDCScope:          "openid, profile, offline_access",
+		common.OIDCCLientID:       "client",
+		common.OIDCClientSecret:   "secret",
+		common.ExtEndpoint:        "https://harbor.test",
+	}
+
+	config.InitWithSettings(conf)
+
+	result := m.Run()
+	if result != 0 {
+		os.Exit(result)
+	}
+}
+
+func TestHelperLoadConf(t *testing.T) {
+	testP := &providerHelper{}
+	assert.Nil(t, testP.setting.Load())
+	err := testP.loadConf()
+	assert.Nil(t, err)
+	assert.Equal(t, "test", testP.setting.Load().(models.OIDCSetting).Name)
+	assert.Nil(t, testP.ep.Load())
+}
+
+func TestHelperCreate(t *testing.T) {
+	testP := &providerHelper{}
+	err := testP.loadConf()
+	assert.Nil(t, err)
+	assert.Nil(t, testP.instance.Load())
+	err = testP.create()
+	assert.Nil(t, err)
+	assert.EqualValues(t, "https://accounts.google.com", testP.ep.Load().(string))
+	assert.NotNil(t, testP.instance.Load())
+}
+
+func TestHelperGet(t *testing.T) {
+	testP := &providerHelper{}
+	p, err := testP.get()
+	assert.Nil(t, err)
+	assert.Equal(t, "https://oauth2.googleapis.com/token", p.Endpoint().TokenURL)
+
+	update := map[string]interface{}{
+		common.OIDCName:           "test",
+		common.OIDCEndpoint:       "https://accounts.google.com",
+		common.OIDCSkipCertVerify: "false",
+		common.OIDCScope:          "openid, profile, offline_access",
+		common.OIDCCLientID:       "client",
+		common.OIDCClientSecret:   "new-secret",
+		common.ExtEndpoint:        "https://harbor.test",
+	}
+	config.GetCfgManager().UpdateConfig(update)
+
+	t.Log("Sleep for 5 seconds")
+	time.Sleep(5 * time.Second)
+	assert.Equal(t, "new-secret", testP.setting.Load().(models.OIDCSetting).ClientSecret)
+}
+
+func TestAuthCodeURL(t *testing.T) {
+	res, err := AuthCodeURL("random")
+	assert.Nil(t, err)
+	u, err := url.ParseRequestURI(res)
+	assert.Nil(t, err)
+	q, err := url.ParseQuery(u.RawQuery)
+	assert.Nil(t, err)
+	assert.Equal(t, "offline", q.Get("access_type"))
+	assert.False(t, strings.Contains(q.Get("scope"), "offline_access"))
+}

src/core/controllers/oidc.go

@@ -0,0 +1,44 @@
+// Copyright 2018 Project Harbor Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//    http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package controllers
+
+import (
+	"fmt"
+	"github.com/goharbor/harbor/src/common"
+	"github.com/goharbor/harbor/src/common/utils"
+	"github.com/goharbor/harbor/src/common/utils/oidc"
+	"github.com/goharbor/harbor/src/core/api"
+	"github.com/goharbor/harbor/src/core/config"
+	"net/http"
+)
+
+// OIDCController handles requests for OIDC login, callback and user onboard
+type OIDCController struct {
+	api.BaseController
+}
+
+// RedirectLogin redirect user's browser to OIDC provider's login page
+func (oc *OIDCController) RedirectLogin() {
+	if mode, _ := config.AuthMode(); mode != common.OIDCAuth {
+		oc.RenderError(http.StatusPreconditionFailed, fmt.Sprintf("Auth Mode: %s is not OIDC based.", mode))
+		return
+	}
+	url, err := oidc.AuthCodeURL(utils.GenerateRandomString())
+	if err != nil {
+		oc.RenderFormatedError(http.StatusInternalServerError, err)
+	}
+	// Force to use the func 'Redirect' of beego.Controller
+	oc.Controller.Redirect(url, http.StatusFound)
+}

src/core/router.go

@@ -37,6 +37,7 @@ func initRouters() {
 		beego.Router("/c/reset", &controllers.CommonController{}, "post:ResetPassword")
 		beego.Router("/c/userExists", &controllers.CommonController{}, "post:UserExists")
 		beego.Router("/c/sendEmail", &controllers.CommonController{}, "get:SendResetEmail")
+		beego.Router("/c/oidc_login", &controllers.OIDCController{}, "get:RedirectLogin")
 
 		// API:
 		beego.Router("/api/projects/:pid([0-9]+)/members/?:pmid([0-9]+)", &api.ProjectMemberAPI{})

src/vendor/github.com/coreos/go-oidc/.gitignore

@@ -0,0 +1,2 @@
+/bin
+/gopath

src/vendor/github.com/coreos/go-oidc/.travis.yml

@@ -0,0 +1,16 @@
+language: go
+
+go:
+  - 1.7.5
+  - 1.8
+
+install:
+ - go get -v -t github.com/coreos/go-oidc/...
+ - go get golang.org/x/tools/cmd/cover
+ - go get github.com/golang/lint/golint
+
+script:
+ - ./test
+
+notifications:
+  email: false

src/vendor/github.com/coreos/go-oidc/CONTRIBUTING.md

@@ -0,0 +1,71 @@
+# How to Contribute
+
+CoreOS projects are [Apache 2.0 licensed](LICENSE) and accept contributions via
+GitHub pull requests.  This document outlines some of the conventions on
+development workflow, commit message formatting, contact points and other
+resources to make it easier to get your contribution accepted.
+
+# Certificate of Origin
+
+By contributing to this project you agree to the Developer Certificate of
+Origin (DCO). This document was created by the Linux Kernel community and is a
+simple statement that you, as a contributor, have the legal right to make the
+contribution. See the [DCO](DCO) file for details.
+
+# Email and Chat
+
+The project currently uses the general CoreOS email list and IRC channel:
+- Email: [coreos-dev](https://groups.google.com/forum/#!forum/coreos-dev)
+- IRC: #[coreos](irc://irc.freenode.org:6667/#coreos) IRC channel on freenode.org
+
+Please avoid emailing maintainers found in the MAINTAINERS file directly. They
+are very busy and read the mailing lists.
+
+## Getting Started
+
+- Fork the repository on GitHub
+- Read the [README](README.md) for build and test instructions
+- Play with the project, submit bugs, submit patches!
+
+## Contribution Flow
+
+This is a rough outline of what a contributor's workflow looks like:
+
+- Create a topic branch from where you want to base your work (usually master).
+- Make commits of logical units.
+- Make sure your commit messages are in the proper format (see below).
+- Push your changes to a topic branch in your fork of the repository.
+- Make sure the tests pass, and add any new tests as appropriate.
+- Submit a pull request to the original repository.
+
+Thanks for your contributions!
+
+### Format of the Commit Message
+
+We follow a rough convention for commit messages that is designed to answer two
+questions: what changed and why. The subject line should feature the what and
+the body of the commit should describe the why.
+
+```
+scripts: add the test-cluster command
+
+this uses tmux to setup a test cluster that you can easily kill and
+start for debugging.
+
+Fixes #38
+```
+
+The format can be described more formally as follows:
+
+```
+<subsystem>: <what changed>
+<BLANK LINE>
+<why this change was made>
+<BLANK LINE>
+<footer>
+```
+
+The first line is the subject and should be no longer than 70 characters, the
+second line is always blank, and other lines should be wrapped at 80 characters.
+This allows the message to be easier to read on GitHub as well as in various
+git tools.

src/vendor/github.com/coreos/go-oidc/DCO

@@ -0,0 +1,36 @@
+Developer Certificate of Origin
+Version 1.1
+
+Copyright (C) 2004, 2006 The Linux Foundation and its contributors.
+660 York Street, Suite 102,
+San Francisco, CA 94110 USA
+
+Everyone is permitted to copy and distribute verbatim copies of this
+license document, but changing it is not allowed.
+
+
+Developer's Certificate of Origin 1.1
+
+By making a contribution to this project, I certify that:
+
+(a) The contribution was created in whole or in part by me and I
+    have the right to submit it under the open source license
+    indicated in the file; or
+
+(b) The contribution is based upon previous work that, to the best
+    of my knowledge, is covered under an appropriate open source
+    license and I have the right under that license to submit that
+    work with modifications, whether created in whole or in part
+    by me, under the same open source license (unless I am
+    permitted to submit under a different license), as indicated
+    in the file; or
+
+(c) The contribution was provided directly to me by some other
+    person who certified (a), (b) or (c) and I have not modified
+    it.
+
+(d) I understand and agree that this project and the contribution
+    are public and that a record of the contribution (including all
+    personal information I submit with it, including my sign-off) is
+    maintained indefinitely and may be redistributed consistent with
+    this project or the open source license(s) involved.

src/vendor/github.com/coreos/go-oidc/LICENSE

@@ -0,0 +1,202 @@
+Apache License
+                           Version 2.0, January 2004
+                        http://www.apache.org/licenses/
+
+   TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION
+
+   1. Definitions.
+
+      "License" shall mean the terms and conditions for use, reproduction,
+      and distribution as defined by Sections 1 through 9 of this document.
+
+      "Licensor" shall mean the copyright owner or entity authorized by
+      the copyright owner that is granting the License.
+
+      "Legal Entity" shall mean the union of the acting entity and all
+      other entities that control, are controlled by, or are under common
+      control with that entity. For the purposes of this definition,
+      "control" means (i) the power, direct or indirect, to cause the
+      direction or management of such entity, whether by contract or
+      otherwise, or (ii) ownership of fifty percent (50%) or more of the
+      outstanding shares, or (iii) beneficial ownership of such entity.
+
+      "You" (or "Your") shall mean an individual or Legal Entity
+      exercising permissions granted by this License.
+
+      "Source" form shall mean the preferred form for making modifications,
+      including but not limited to software source code, documentation
+      source, and configuration files.
+
+      "Object" form shall mean any form resulting from mechanical
+      transformation or translation of a Source form, including but
+      not limited to compiled object code, generated documentation,
+      and conversions to other media types.
+
+      "Work" shall mean the work of authorship, whether in Source or
+      Object form, made available under the License, as indicated by a
+      copyright notice that is included in or attached to the work
+      (an example is provided in the Appendix below).
+
+      "Derivative Works" shall mean any work, whether in Source or Object
+      form, that is based on (or derived from) the Work and for which the
+      editorial revisions, annotations, elaborations, or other modifications
+      represent, as a whole, an original work of authorship. For the purposes
+      of this License, Derivative Works shall not include works that remain
+      separable from, or merely link (or bind by name) to the interfaces of,
+      the Work and Derivative Works thereof.
+
+      "Contribution" shall mean any work of authorship, including
+      the original version of the Work and any modifications or additions
+      to that Work or Derivative Works thereof, that is intentionally
+      submitted to Licensor for inclusion in the Work by the copyright owner
+      or by an individual or Legal Entity authorized to submit on behalf of
+      the copyright owner. For the purposes of this definition, "submitted"
+      means any form of electronic, verbal, or written communication sent
+      to the Licensor or its representatives, including but not limited to
+      communication on electronic mailing lists, source code control systems,
+      and issue tracking systems that are managed by, or on behalf of, the
+      Licensor for the purpose of discussing and improving the Work, but
+      excluding communication that is conspicuously marked or otherwise
+      designated in writing by the copyright owner as "Not a Contribution."
+
+      "Contributor" shall mean Licensor and any individual or Legal Entity
+      on behalf of whom a Contribution has been received by Licensor and
+      subsequently incorporated within the Work.
+
+   2. Grant of Copyright License. Subject to the terms and conditions of
+      this License, each Contributor hereby grants to You a perpetual,
+      worldwide, non-exclusive, no-charge, royalty-free, irrevocable
+      copyright license to reproduce, prepare Derivative Works of,
+      publicly display, publicly perform, sublicense, and distribute the
+      Work and such Derivative Works in Source or Object form.
+
+   3. Grant of Patent License. Subject to the terms and conditions of
+      this License, each Contributor hereby grants to You a perpetual,
+      worldwide, non-exclusive, no-charge, royalty-free, irrevocable
+      (except as stated in this section) patent license to make, have made,
+      use, offer to sell, sell, import, and otherwise transfer the Work,
+      where such license applies only to those patent claims licensable
+      by such Contributor that are necessarily infringed by their
+      Contribution(s) alone or by combination of their Contribution(s)
+      with the Work to which such Contribution(s) was submitted. If You
+      institute patent litigation against any entity (including a
+      cross-claim or counterclaim in a lawsuit) alleging that the Work
+      or a Contribution incorporated within the Work constitutes direct
+      or contributory patent infringement, then any patent licenses
+      granted to You under this License for that Work shall terminate
+      as of the date such litigation is filed.
+
+   4. Redistribution. You may reproduce and distribute copies of the
+      Work or Derivative Works thereof in any medium, with or without
+      modifications, and in Source or Object form, provided that You
+      meet the following conditions:
+
+      (a) You must give any other recipients of the Work or
+          Derivative Works a copy of this License; and
+
+      (b) You must cause any modified files to carry prominent notices
+          stating that You changed the files; and
+
+      (c) You must retain, in the Source form of any Derivative Works
+          that You distribute, all copyright, patent, trademark, and
+          attribution notices from the Source form of the Work,
+          excluding those notices that do not pertain to any part of
+          the Derivative Works; and
+
+      (d) If the Work includes a "NOTICE" text file as part of its
+          distribution, then any Derivative Works that You distribute must
+          include a readable copy of the attribution notices contained
+          within such NOTICE file, excluding those notices that do not
+          pertain to any part of the Derivative Works, in at least one
+          of the following places: within a NOTICE text file distributed
+          as part of the Derivative Works; within the Source form or
+          documentation, if provided along with the Derivative Works; or,
+          within a display generated by the Derivative Works, if and
+          wherever such third-party notices normally appear. The contents
+          of the NOTICE file are for informational purposes only and
+          do not modify the License. You may add Your own attribution
+          notices within Derivative Works that You distribute, alongside
+          or as an addendum to the NOTICE text from the Work, provided
+          that such additional attribution notices cannot be construed
+          as modifying the License.
+
+      You may add Your own copyright statement to Your modifications and
+      may provide additional or different license terms and conditions
+      for use, reproduction, or distribution of Your modifications, or
+      for any such Derivative Works as a whole, provided Your use,
+      reproduction, and distribution of the Work otherwise complies with
+      the conditions stated in this License.
+
+   5. Submission of Contributions. Unless You explicitly state otherwise,
+      any Contribution intentionally submitted for inclusion in the Work
+      by You to the Licensor shall be under the terms and conditions of
+      this License, without any additional terms or conditions.
+      Notwithstanding the above, nothing herein shall supersede or modify
+      the terms of any separate license agreement you may have executed
+      with Licensor regarding such Contributions.
+
+   6. Trademarks. This License does not grant permission to use the trade
+      names, trademarks, service marks, or product names of the Licensor,
+      except as required for reasonable and customary use in describing the
+      origin of the Work and reproducing the content of the NOTICE file.
+
+   7. Disclaimer of Warranty. Unless required by applicable law or
+      agreed to in writing, Licensor provides the Work (and each
+      Contributor provides its Contributions) on an "AS IS" BASIS,
+      WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+      implied, including, without limitation, any warranties or conditions
+      of TITLE, NON-INFRINGEMENT, MERCHANTABILITY, or FITNESS FOR A
+      PARTICULAR PURPOSE. You are solely responsible for determining the
+      appropriateness of using or redistributing the Work and assume any
+      risks associated with Your exercise of permissions under this License.
+
+   8. Limitation of Liability. In no event and under no legal theory,
+      whether in tort (including negligence), contract, or otherwise,
+      unless required by applicable law (such as deliberate and grossly
+      negligent acts) or agreed to in writing, shall any Contributor be
+      liable to You for damages, including any direct, indirect, special,
+      incidental, or consequential damages of any character arising as a
+      result of this License or out of the use or inability to use the
+      Work (including but not limited to damages for loss of goodwill,
+      work stoppage, computer failure or malfunction, or any and all
+      other commercial damages or losses), even if such Contributor
+      has been advised of the possibility of such damages.
+
+   9. Accepting Warranty or Additional Liability. While redistributing
+      the Work or Derivative Works thereof, You may choose to offer,
+      and charge a fee for, acceptance of support, warranty, indemnity,
+      or other liability obligations and/or rights consistent with this
+      License. However, in accepting such obligations, You may act only
+      on Your own behalf and on Your sole responsibility, not on behalf
+      of any other Contributor, and only if You agree to indemnify,
+      defend, and hold each Contributor harmless for any liability
+      incurred by, or claims asserted against, such Contributor by reason
+      of your accepting any such warranty or additional liability.
+
+   END OF TERMS AND CONDITIONS
+
+   APPENDIX: How to apply the Apache License to your work.
+
+      To apply the Apache License to your work, attach the following
+      boilerplate notice, with the fields enclosed by brackets "{}"
+      replaced with your own identifying information. (Don't include
+      the brackets!)  The text should be enclosed in the appropriate
+      comment syntax for the file format. We also recommend that a
+      file or class name and description of purpose be included on the
+      same "printed page" as the copyright notice for easier
+      identification within third-party archives.
+
+   Copyright {yyyy} {name of copyright owner}
+
+   Licensed under the Apache License, Version 2.0 (the "License");
+   you may not use this file except in compliance with the License.
+   You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
+

src/vendor/github.com/coreos/go-oidc/MAINTAINERS

@@ -0,0 +1,2 @@
+Eric Chiang <echiang@redhat.com> (@ericchiang)
+Rithu Leena John <rjohn@redhat.com> (@rithujohn191)

src/vendor/github.com/coreos/go-oidc/NOTICE

@@ -0,0 +1,5 @@
+CoreOS Project
+Copyright 2014 CoreOS, Inc
+
+This product includes software developed at CoreOS, Inc.
+(http://www.coreos.com/).

src/vendor/github.com/coreos/go-oidc/README.md

@@ -0,0 +1,72 @@
+# go-oidc
+
+[![GoDoc](https://godoc.org/github.com/coreos/go-oidc?status.svg)](https://godoc.org/github.com/coreos/go-oidc)
+[![Build Status](https://travis-ci.org/coreos/go-oidc.png?branch=master)](https://travis-ci.org/coreos/go-oidc)
+
+## OpenID Connect support for Go
+
+This package enables OpenID Connect support for the [golang.org/x/oauth2](https://godoc.org/golang.org/x/oauth2) package.
+
+```go
+provider, err := oidc.NewProvider(ctx, "https://accounts.google.com")
+if err != nil {
+    // handle error
+}
+
+// Configure an OpenID Connect aware OAuth2 client.
+oauth2Config := oauth2.Config{
+    ClientID:     clientID,
+    ClientSecret: clientSecret,
+    RedirectURL:  redirectURL,
+
+    // Discovery returns the OAuth2 endpoints.
+    Endpoint: provider.Endpoint(),
+
+    // "openid" is a required scope for OpenID Connect flows.
+    Scopes: []string{oidc.ScopeOpenID, "profile", "email"},
+}
+```
+
+OAuth2 redirects are unchanged.
+
+```go
+func handleRedirect(w http.ResponseWriter, r *http.Request) {
+    http.Redirect(w, r, oauth2Config.AuthCodeURL(state), http.StatusFound)
+}
+```
+
+The on responses, the provider can be used to verify ID Tokens.
+
+```go
+var verifier = provider.Verifier(&oidc.Config{ClientID: clientID})
+
+func handleOAuth2Callback(w http.ResponseWriter, r *http.Request) {
+    // Verify state and errors.
+
+    oauth2Token, err := oauth2Config.Exchange(ctx, r.URL.Query().Get("code"))
+    if err != nil {
+        // handle error
+    }
+
+    // Extract the ID Token from OAuth2 token.
+    rawIDToken, ok := oauth2Token.Extra("id_token").(string)
+    if !ok {
+        // handle missing token
+    }
+
+    // Parse and verify ID Token payload.
+    idToken, err := verifier.Verify(ctx, rawIDToken)
+    if err != nil {
+        // handle error
+    }
+
+    // Extract custom claims
+    var claims struct {
+        Email    string `json:"email"`
+        Verified bool   `json:"email_verified"`
+    }
+    if err := idToken.Claims(&claims); err != nil {
+        // handle error
+    }
+}
+```

src/vendor/github.com/coreos/go-oidc/code-of-conduct.md

@@ -0,0 +1,61 @@
+## CoreOS Community Code of Conduct
+
+### Contributor Code of Conduct
+
+As contributors and maintainers of this project, and in the interest of
+fostering an open and welcoming community, we pledge to respect all people who
+contribute through reporting issues, posting feature requests, updating
+documentation, submitting pull requests or patches, and other activities.
+
+We are committed to making participation in this project a harassment-free
+experience for everyone, regardless of level of experience, gender, gender
+identity and expression, sexual orientation, disability, personal appearance,
+body size, race, ethnicity, age, religion, or nationality.
+
+Examples of unacceptable behavior by participants include:
+
+* The use of sexualized language or imagery
+* Personal attacks
+* Trolling or insulting/derogatory comments
+* Public or private harassment
+* Publishing others' private information, such as physical or electronic addresses, without explicit permission
+* Other unethical or unprofessional conduct.
+
+Project maintainers have the right and responsibility to remove, edit, or
+reject comments, commits, code, wiki edits, issues, and other contributions
+that are not aligned to this Code of Conduct. By adopting this Code of Conduct,
+project maintainers commit themselves to fairly and consistently applying these
+principles to every aspect of managing this project. Project maintainers who do
+not follow or enforce the Code of Conduct may be permanently removed from the
+project team.
+
+This code of conduct applies both within project spaces and in public spaces
+when an individual is representing the project or its community.
+
+Instances of abusive, harassing, or otherwise unacceptable behavior may be
+reported by contacting a project maintainer, Brandon Philips
+<brandon.philips@coreos.com>, and/or Rithu John <rithu.john@coreos.com>.
+
+This Code of Conduct is adapted from the Contributor Covenant
+(http://contributor-covenant.org), version 1.2.0, available at
+http://contributor-covenant.org/version/1/2/0/
+
+### CoreOS Events Code of Conduct
+
+CoreOS events are working conferences intended for professional networking and
+collaboration in the CoreOS community. Attendees are expected to behave
+according to professional standards and in accordance with their employer’s
+policies on appropriate workplace behavior.
+
+While at CoreOS events or related social networking opportunities, attendees
+should not engage in discriminatory or offensive speech or actions including
+but not limited to gender, sexuality, race, age, disability, or religion.
+Speakers should be especially aware of these concerns.
+
+CoreOS does not condone any statements by speakers contrary to these standards.
+CoreOS reserves the right to deny entrance and/or eject from an event (without
+refund) any individual found to be engaging in discriminatory or offensive
+speech or actions.
+
+Please bring any concerns to the immediate attention of designated on-site
+staff, Brandon Philips <brandon.philips@coreos.com>, and/or Rithu John <rithu.john@coreos.com>.

src/vendor/github.com/coreos/go-oidc/jose.go

@@ -0,0 +1,20 @@
+// +build !golint
+
+// Don't lint this file. We don't want to have to add a comment to each constant.
+
+package oidc
+
+const (
+	// JOSE asymmetric signing algorithm values as defined by RFC 7518
+	//
+	// see: https://tools.ietf.org/html/rfc7518#section-3.1
+	RS256 = "RS256" // RSASSA-PKCS-v1.5 using SHA-256
+	RS384 = "RS384" // RSASSA-PKCS-v1.5 using SHA-384
+	RS512 = "RS512" // RSASSA-PKCS-v1.5 using SHA-512
+	ES256 = "ES256" // ECDSA using P-256 and SHA-256
+	ES384 = "ES384" // ECDSA using P-384 and SHA-384
+	ES512 = "ES512" // ECDSA using P-521 and SHA-512
+	PS256 = "PS256" // RSASSA-PSS using SHA256 and MGF1-SHA256
+	PS384 = "PS384" // RSASSA-PSS using SHA384 and MGF1-SHA384
+	PS512 = "PS512" // RSASSA-PSS using SHA512 and MGF1-SHA512
+)

src/vendor/github.com/coreos/go-oidc/jwks.go

@@ -0,0 +1,228 @@
+package oidc
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	"io/ioutil"
+	"net/http"
+	"sync"
+	"time"
+
+	"github.com/pquerna/cachecontrol"
+	jose "gopkg.in/square/go-jose.v2"
+)
+
+// keysExpiryDelta is the allowed clock skew between a client and the OpenID Connect
+// server.
+//
+// When keys expire, they are valid for this amount of time after.
+//
+// If the keys have not expired, and an ID Token claims it was signed by a key not in
+// the cache, if and only if the keys expire in this amount of time, the keys will be
+// updated.
+const keysExpiryDelta = 30 * time.Second
+
+// NewRemoteKeySet returns a KeySet that can validate JSON web tokens by using HTTP
+// GETs to fetch JSON web token sets hosted at a remote URL. This is automatically
+// used by NewProvider using the URLs returned by OpenID Connect discovery, but is
+// exposed for providers that don't support discovery or to prevent round trips to the
+// discovery URL.
+//
+// The returned KeySet is a long lived verifier that caches keys based on cache-control
+// headers. Reuse a common remote key set instead of creating new ones as needed.
+//
+// The behavior of the returned KeySet is undefined once the context is canceled.
+func NewRemoteKeySet(ctx context.Context, jwksURL string) KeySet {
+	return newRemoteKeySet(ctx, jwksURL, time.Now)
+}
+
+func newRemoteKeySet(ctx context.Context, jwksURL string, now func() time.Time) *remoteKeySet {
+	if now == nil {
+		now = time.Now
+	}
+	return &remoteKeySet{jwksURL: jwksURL, ctx: ctx, now: now}
+}
+
+type remoteKeySet struct {
+	jwksURL string
+	ctx     context.Context
+	now     func() time.Time
+
+	// guard all other fields
+	mu sync.Mutex
+
+	// inflight suppresses parallel execution of updateKeys and allows
+	// multiple goroutines to wait for its result.
+	inflight *inflight
+
+	// A set of cached keys and their expiry.
+	cachedKeys []jose.JSONWebKey
+	expiry     time.Time
+}
+
+// inflight is used to wait on some in-flight request from multiple goroutines.
+type inflight struct {
+	doneCh chan struct{}
+
+	keys []jose.JSONWebKey
+	err  error
+}
+
+func newInflight() *inflight {
+	return &inflight{doneCh: make(chan struct{})}
+}
+
+// wait returns a channel that multiple goroutines can receive on. Once it returns
+// a value, the inflight request is done and result() can be inspected.
+func (i *inflight) wait() <-chan struct{} {
+	return i.doneCh
+}
+
+// done can only be called by a single goroutine. It records the result of the
+// inflight request and signals other goroutines that the result is safe to
+// inspect.
+func (i *inflight) done(keys []jose.JSONWebKey, err error) {
+	i.keys = keys
+	i.err = err
+	close(i.doneCh)
+}
+
+// result cannot be called until the wait() channel has returned a value.
+func (i *inflight) result() ([]jose.JSONWebKey, error) {
+	return i.keys, i.err
+}
+
+func (r *remoteKeySet) VerifySignature(ctx context.Context, jwt string) ([]byte, error) {
+	jws, err := jose.ParseSigned(jwt)
+	if err != nil {
+		return nil, fmt.Errorf("oidc: malformed jwt: %v", err)
+	}
+	return r.verify(ctx, jws)
+}
+
+func (r *remoteKeySet) verify(ctx context.Context, jws *jose.JSONWebSignature) ([]byte, error) {
+	// We don't support JWTs signed with multiple signatures.
+	keyID := ""
+	for _, sig := range jws.Signatures {
+		keyID = sig.Header.KeyID
+		break
+	}
+
+	keys, expiry := r.keysFromCache()
+
+	// Don't check expiry yet. This optimizes for when the provider is unavailable.
+	for _, key := range keys {
+		if keyID == "" || key.KeyID == keyID {
+			if payload, err := jws.Verify(&key); err == nil {
+				return payload, nil
+			}
+		}
+	}
+
+	if !r.now().Add(keysExpiryDelta).After(expiry) {
+		// Keys haven't expired, don't refresh.
+		return nil, errors.New("failed to verify id token signature")
+	}
+
+	keys, err := r.keysFromRemote(ctx)
+	if err != nil {
+		return nil, fmt.Errorf("fetching keys %v", err)
+	}
+
+	for _, key := range keys {
+		if keyID == "" || key.KeyID == keyID {
+			if payload, err := jws.Verify(&key); err == nil {
+				return payload, nil
+			}
+		}
+	}
+	return nil, errors.New("failed to verify id token signature")
+}
+
+func (r *remoteKeySet) keysFromCache() (keys []jose.JSONWebKey, expiry time.Time) {
+	r.mu.Lock()
+	defer r.mu.Unlock()
+	return r.cachedKeys, r.expiry
+}
+
+// keysFromRemote syncs the key set from the remote set, records the values in the
+// cache, and returns the key set.
+func (r *remoteKeySet) keysFromRemote(ctx context.Context) ([]jose.JSONWebKey, error) {
+	// Need to lock to inspect the inflight request field.
+	r.mu.Lock()
+	// If there's not a current inflight request, create one.
+	if r.inflight == nil {
+		r.inflight = newInflight()
+
+		// This goroutine has exclusive ownership over the current inflight
+		// request. It releases the resource by nil'ing the inflight field
+		// once the goroutine is done.
+		go func() {
+			// Sync keys and finish inflight when that's done.
+			keys, expiry, err := r.updateKeys()
+
+			r.inflight.done(keys, err)
+
+			// Lock to update the keys and indicate that there is no longer an
+			// inflight request.
+			r.mu.Lock()
+			defer r.mu.Unlock()
+
+			if err == nil {
+				r.cachedKeys = keys
+				r.expiry = expiry
+			}
+
+			// Free inflight so a different request can run.
+			r.inflight = nil
+		}()
+	}
+	inflight := r.inflight
+	r.mu.Unlock()
+
+	select {
+	case <-ctx.Done():
+		return nil, ctx.Err()
+	case <-inflight.wait():
+		return inflight.result()
+	}
+}
+
+func (r *remoteKeySet) updateKeys() ([]jose.JSONWebKey, time.Time, error) {
+	req, err := http.NewRequest("GET", r.jwksURL, nil)
+	if err != nil {
+		return nil, time.Time{}, fmt.Errorf("oidc: can't create request: %v", err)
+	}
+
+	resp, err := doRequest(r.ctx, req)
+	if err != nil {
+		return nil, time.Time{}, fmt.Errorf("oidc: get keys failed %v", err)
+	}
+	defer resp.Body.Close()
+
+	body, err := ioutil.ReadAll(resp.Body)
+	if err != nil {
+		return nil, time.Time{}, fmt.Errorf("unable to read response body: %v", err)
+	}
+
+	if resp.StatusCode != http.StatusOK {
+		return nil, time.Time{}, fmt.Errorf("oidc: get keys failed: %s %s", resp.Status, body)
+	}
+
+	var keySet jose.JSONWebKeySet
+	err = unmarshalResp(resp, body, &keySet)
+	if err != nil {
+		return nil, time.Time{}, fmt.Errorf("oidc: failed to decode keys: %v %s", err, body)
+	}
+
+	// If the server doesn't provide cache control headers, assume the
+	// keys expire immediately.
+	expiry := r.now()
+
+	_, e, err := cachecontrol.CachableResponse(req, resp, cachecontrol.Options{})
+	if err == nil && e.After(expiry) {
+		expiry = e
+	}
+	return keySet.Keys, expiry, nil
+}

src/vendor/github.com/coreos/go-oidc/oidc.go

@@ -0,0 +1,374 @@
+// Package oidc implements OpenID Connect client logic for the golang.org/x/oauth2 package.
+package oidc
+
+import (
+	"context"
+	"crypto/sha256"
+	"crypto/sha512"
+	"encoding/base64"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"hash"
+	"io/ioutil"
+	"mime"
+	"net/http"
+	"strings"
+	"time"
+
+	"golang.org/x/oauth2"
+	jose "gopkg.in/square/go-jose.v2"
+)
+
+const (
+	// ScopeOpenID is the mandatory scope for all OpenID Connect OAuth2 requests.
+	ScopeOpenID = "openid"
+
+	// ScopeOfflineAccess is an optional scope defined by OpenID Connect for requesting
+	// OAuth2 refresh tokens.
+	//
+	// Support for this scope differs between OpenID Connect providers. For instance
+	// Google rejects it, favoring appending "access_type=offline" as part of the
+	// authorization request instead.
+	//
+	// See: https://openid.net/specs/openid-connect-core-1_0.html#OfflineAccess
+	ScopeOfflineAccess = "offline_access"
+)
+
+var (
+	errNoAtHash      = errors.New("id token did not have an access token hash")
+	errInvalidAtHash = errors.New("access token hash does not match value in ID token")
+)
+
+// ClientContext returns a new Context that carries the provided HTTP client.
+//
+// This method sets the same context key used by the golang.org/x/oauth2 package,
+// so the returned context works for that package too.
+//
+//    myClient := &http.Client{}
+//    ctx := oidc.ClientContext(parentContext, myClient)
+//
+//    // This will use the custom client
+//    provider, err := oidc.NewProvider(ctx, "https://accounts.example.com")
+//
+func ClientContext(ctx context.Context, client *http.Client) context.Context {
+	return context.WithValue(ctx, oauth2.HTTPClient, client)
+}
+
+func doRequest(ctx context.Context, req *http.Request) (*http.Response, error) {
+	client := http.DefaultClient
+	if c, ok := ctx.Value(oauth2.HTTPClient).(*http.Client); ok {
+		client = c
+	}
+	return client.Do(req.WithContext(ctx))
+}
+
+// Provider represents an OpenID Connect server's configuration.
+type Provider struct {
+	issuer      string
+	authURL     string
+	tokenURL    string
+	userInfoURL string
+
+	// Raw claims returned by the server.
+	rawClaims []byte
+
+	remoteKeySet KeySet
+}
+
+type cachedKeys struct {
+	keys   []jose.JSONWebKey
+	expiry time.Time
+}
+
+type providerJSON struct {
+	Issuer      string `json:"issuer"`
+	AuthURL     string `json:"authorization_endpoint"`
+	TokenURL    string `json:"token_endpoint"`
+	JWKSURL     string `json:"jwks_uri"`
+	UserInfoURL string `json:"userinfo_endpoint"`
+}
+
+// NewProvider uses the OpenID Connect discovery mechanism to construct a Provider.
+//
+// The issuer is the URL identifier for the service. For example: "https://accounts.google.com"
+// or "https://login.salesforce.com".
+func NewProvider(ctx context.Context, issuer string) (*Provider, error) {
+	wellKnown := strings.TrimSuffix(issuer, "/") + "/.well-known/openid-configuration"
+	req, err := http.NewRequest("GET", wellKnown, nil)
+	if err != nil {
+		return nil, err
+	}
+	resp, err := doRequest(ctx, req)
+	if err != nil {
+		return nil, err
+	}
+	defer resp.Body.Close()
+
+	body, err := ioutil.ReadAll(resp.Body)
+	if err != nil {
+		return nil, fmt.Errorf("unable to read response body: %v", err)
+	}
+
+	if resp.StatusCode != http.StatusOK {
+		return nil, fmt.Errorf("%s: %s", resp.Status, body)
+	}
+
+	var p providerJSON
+	err = unmarshalResp(resp, body, &p)
+	if err != nil {
+		return nil, fmt.Errorf("oidc: failed to decode provider discovery object: %v", err)
+	}
+
+	if p.Issuer != issuer {
+		return nil, fmt.Errorf("oidc: issuer did not match the issuer returned by provider, expected %q got %q", issuer, p.Issuer)
+	}
+	return &Provider{
+		issuer:       p.Issuer,
+		authURL:      p.AuthURL,
+		tokenURL:     p.TokenURL,
+		userInfoURL:  p.UserInfoURL,
+		rawClaims:    body,
+		remoteKeySet: NewRemoteKeySet(ctx, p.JWKSURL),
+	}, nil
+}
+
+// Claims unmarshals raw fields returned by the server during discovery.
+//
+//    var claims struct {
+//        ScopesSupported []string `json:"scopes_supported"`
+//        ClaimsSupported []string `json:"claims_supported"`
+//    }
+//
+//    if err := provider.Claims(&claims); err != nil {
+//        // handle unmarshaling error
+//    }
+//
+// For a list of fields defined by the OpenID Connect spec see:
+// https://openid.net/specs/openid-connect-discovery-1_0.html#ProviderMetadata
+func (p *Provider) Claims(v interface{}) error {
+	if p.rawClaims == nil {
+		return errors.New("oidc: claims not set")
+	}
+	return json.Unmarshal(p.rawClaims, v)
+}
+
+// Endpoint returns the OAuth2 auth and token endpoints for the given provider.
+func (p *Provider) Endpoint() oauth2.Endpoint {
+	return oauth2.Endpoint{AuthURL: p.authURL, TokenURL: p.tokenURL}
+}
+
+// UserInfo represents the OpenID Connect userinfo claims.
+type UserInfo struct {
+	Subject       string `json:"sub"`
+	Profile       string `json:"profile"`
+	Email         string `json:"email"`
+	EmailVerified bool   `json:"email_verified"`
+
+	claims []byte
+}
+
+// Claims unmarshals the raw JSON object claims into the provided object.
+func (u *UserInfo) Claims(v interface{}) error {
+	if u.claims == nil {
+		return errors.New("oidc: claims not set")
+	}
+	return json.Unmarshal(u.claims, v)
+}
+
+// UserInfo uses the token source to query the provider's user info endpoint.
+func (p *Provider) UserInfo(ctx context.Context, tokenSource oauth2.TokenSource) (*UserInfo, error) {
+	if p.userInfoURL == "" {
+		return nil, errors.New("oidc: user info endpoint is not supported by this provider")
+	}
+
+	req, err := http.NewRequest("GET", p.userInfoURL, nil)
+	if err != nil {
+		return nil, fmt.Errorf("oidc: create GET request: %v", err)
+	}
+
+	token, err := tokenSource.Token()
+	if err != nil {
+		return nil, fmt.Errorf("oidc: get access token: %v", err)
+	}
+	token.SetAuthHeader(req)
+
+	resp, err := doRequest(ctx, req)
+	if err != nil {
+		return nil, err
+	}
+	defer resp.Body.Close()
+	body, err := ioutil.ReadAll(resp.Body)
+	if err != nil {
+		return nil, err
+	}
+	if resp.StatusCode != http.StatusOK {
+		return nil, fmt.Errorf("%s: %s", resp.Status, body)
+	}
+
+	var userInfo UserInfo
+	if err := json.Unmarshal(body, &userInfo); err != nil {
+		return nil, fmt.Errorf("oidc: failed to decode userinfo: %v", err)
+	}
+	userInfo.claims = body
+	return &userInfo, nil
+}
+
+// IDToken is an OpenID Connect extension that provides a predictable representation
+// of an authorization event.
+//
+// The ID Token only holds fields OpenID Connect requires. To access additional
+// claims returned by the server, use the Claims method.
+type IDToken struct {
+	// The URL of the server which issued this token. OpenID Connect
+	// requires this value always be identical to the URL used for
+	// initial discovery.
+	//
+	// Note: Because of a known issue with Google Accounts' implementation
+	// this value may differ when using Google.
+	//
+	// See: https://developers.google.com/identity/protocols/OpenIDConnect#obtainuserinfo
+	Issuer string
+
+	// The client ID, or set of client IDs, that this token is issued for. For
+	// common uses, this is the client that initialized the auth flow.
+	//
+	// This package ensures the audience contains an expected value.
+	Audience []string
+
+	// A unique string which identifies the end user.
+	Subject string
+
+	// Expiry of the token. Ths package will not process tokens that have
+	// expired unless that validation is explicitly turned off.
+	Expiry time.Time
+	// When the token was issued by the provider.
+	IssuedAt time.Time
+
+	// Initial nonce provided during the authentication redirect.
+	//
+	// This package does NOT provided verification on the value of this field
+	// and it's the user's responsibility to ensure it contains a valid value.
+	Nonce string
+
+	// at_hash claim, if set in the ID token. Callers can verify an access token
+	// that corresponds to the ID token using the VerifyAccessToken method.
+	AccessTokenHash string
+
+	// signature algorithm used for ID token, needed to compute a verification hash of an
+	// access token
+	sigAlgorithm string
+
+	// Raw payload of the id_token.
+	claims []byte
+}
+
+// Claims unmarshals the raw JSON payload of the ID Token into a provided struct.
+//
+//		idToken, err := idTokenVerifier.Verify(rawIDToken)
+//		if err != nil {
+//			// handle error
+//		}
+//		var claims struct {
+//			Email         string `json:"email"`
+//			EmailVerified bool   `json:"email_verified"`
+//		}
+//		if err := idToken.Claims(&claims); err != nil {
+//			// handle error
+//		}
+//
+func (i *IDToken) Claims(v interface{}) error {
+	if i.claims == nil {
+		return errors.New("oidc: claims not set")
+	}
+	return json.Unmarshal(i.claims, v)
+}
+
+// VerifyAccessToken verifies that the hash of the access token that corresponds to the iD token
+// matches the hash in the id token. It returns an error if the hashes  don't match.
+// It is the caller's responsibility to ensure that the optional access token hash is present for the ID token
+// before calling this method. See https://openid.net/specs/openid-connect-core-1_0.html#CodeIDToken
+func (i *IDToken) VerifyAccessToken(accessToken string) error {
+	if i.AccessTokenHash == "" {
+		return errNoAtHash
+	}
+	var h hash.Hash
+	switch i.sigAlgorithm {
+	case RS256, ES256, PS256:
+		h = sha256.New()
+	case RS384, ES384, PS384:
+		h = sha512.New384()
+	case RS512, ES512, PS512:
+		h = sha512.New()
+	default:
+		return fmt.Errorf("oidc: unsupported signing algorithm %q", i.sigAlgorithm)
+	}
+	h.Write([]byte(accessToken)) // hash documents that Write will never return an error
+	sum := h.Sum(nil)[:h.Size()/2]
+	actual := base64.RawURLEncoding.EncodeToString(sum)
+	if actual != i.AccessTokenHash {
+		return errInvalidAtHash
+	}
+	return nil
+}
+
+type idToken struct {
+	Issuer   string   `json:"iss"`
+	Subject  string   `json:"sub"`
+	Audience audience `json:"aud"`
+	Expiry   jsonTime `json:"exp"`
+	IssuedAt jsonTime `json:"iat"`
+	Nonce    string   `json:"nonce"`
+	AtHash   string   `json:"at_hash"`
+}
+
+type audience []string
+
+func (a *audience) UnmarshalJSON(b []byte) error {
+	var s string
+	if json.Unmarshal(b, &s) == nil {
+		*a = audience{s}
+		return nil
+	}
+	var auds []string
+	if err := json.Unmarshal(b, &auds); err != nil {
+		return err
+	}
+	*a = audience(auds)
+	return nil
+}
+
+type jsonTime time.Time
+
+func (j *jsonTime) UnmarshalJSON(b []byte) error {
+	var n json.Number
+	if err := json.Unmarshal(b, &n); err != nil {
+		return err
+	}
+	var unix int64
+
+	if t, err := n.Int64(); err == nil {
+		unix = t
+	} else {
+		f, err := n.Float64()
+		if err != nil {
+			return err
+		}
+		unix = int64(f)
+	}
+	*j = jsonTime(time.Unix(unix, 0))
+	return nil
+}
+
+func unmarshalResp(r *http.Response, body []byte, v interface{}) error {
+	err := json.Unmarshal(body, &v)
+	if err == nil {
+		return nil
+	}
+	ct := r.Header.Get("Content-Type")
+	mediaType, _, parseErr := mime.ParseMediaType(ct)
+	if parseErr == nil && mediaType == "application/json" {
+		return fmt.Errorf("got Content-Type = application/json, but could not unmarshal as JSON: %v", err)
+	}
+	return fmt.Errorf("expected Content-Type = application/json, got %q: %v", ct, err)
+}

src/vendor/github.com/coreos/go-oidc/test

@@ -0,0 +1,16 @@
+#!/bin/bash
+
+set -e
+
+# Filter out any files with a !golint build tag.
+LINTABLE=$( go list -tags=golint -f '
+  {{- range $i, $file := .GoFiles -}}
+    {{ $file }} {{ end }}
+  {{ range $i, $file := .TestGoFiles -}}
+    {{ $file }} {{ end }}' github.com/coreos/go-oidc )
+
+go test -v -i -race github.com/coreos/go-oidc/...
+go test -v -race github.com/coreos/go-oidc/...
+golint -set_exit_status $LINTABLE
+go vet github.com/coreos/go-oidc/...
+go build -v ./example/...

src/vendor/github.com/coreos/go-oidc/verify.go

@@ -0,0 +1,243 @@
+package oidc
+
+import (
+	"bytes"
+	"context"
+	"encoding/base64"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"strings"
+	"time"
+
+	"golang.org/x/oauth2"
+	jose "gopkg.in/square/go-jose.v2"
+)
+
+const (
+	issuerGoogleAccounts         = "https://accounts.google.com"
+	issuerGoogleAccountsNoScheme = "accounts.google.com"
+)
+
+// KeySet is a set of publc JSON Web Keys that can be used to validate the signature
+// of JSON web tokens. This is expected to be backed by a remote key set through
+// provider metadata discovery or an in-memory set of keys delivered out-of-band.
+type KeySet interface {
+	// VerifySignature parses the JSON web token, verifies the signature, and returns
+	// the raw payload. Header and claim fields are validated by other parts of the
+	// package. For example, the KeySet does not need to check values such as signature
+	// algorithm, issuer, and audience since the IDTokenVerifier validates these values
+	// independently.
+	//
+	// If VerifySignature makes HTTP requests to verify the token, it's expected to
+	// use any HTTP client associated with the context through ClientContext.
+	VerifySignature(ctx context.Context, jwt string) (payload []byte, err error)
+}
+
+// IDTokenVerifier provides verification for ID Tokens.
+type IDTokenVerifier struct {
+	keySet KeySet
+	config *Config
+	issuer string
+}
+
+// NewVerifier returns a verifier manually constructed from a key set and issuer URL.
+//
+// It's easier to use provider discovery to construct an IDTokenVerifier than creating
+// one directly. This method is intended to be used with provider that don't support
+// metadata discovery, or avoiding round trips when the key set URL is already known.
+//
+// This constructor can be used to create a verifier directly using the issuer URL and
+// JSON Web Key Set URL without using discovery:
+//
+//		keySet := oidc.NewRemoteKeySet(ctx, "https://www.googleapis.com/oauth2/v3/certs")
+//		verifier := oidc.NewVerifier("https://accounts.google.com", keySet, config)
+//
+// Since KeySet is an interface, this constructor can also be used to supply custom
+// public key sources. For example, if a user wanted to supply public keys out-of-band
+// and hold them statically in-memory:
+//
+//		// Custom KeySet implementation.
+//		keySet := newStatisKeySet(publicKeys...)
+//
+//		// Verifier uses the custom KeySet implementation.
+//		verifier := oidc.NewVerifier("https://auth.example.com", keySet, config)
+//
+func NewVerifier(issuerURL string, keySet KeySet, config *Config) *IDTokenVerifier {
+	return &IDTokenVerifier{keySet: keySet, config: config, issuer: issuerURL}
+}
+
+// Config is the configuration for an IDTokenVerifier.
+type Config struct {
+	// Expected audience of the token. For a majority of the cases this is expected to be
+	// the ID of the client that initialized the login flow. It may occasionally differ if
+	// the provider supports the authorizing party (azp) claim.
+	//
+	// If not provided, users must explicitly set SkipClientIDCheck.
+	ClientID string
+	// If specified, only this set of algorithms may be used to sign the JWT.
+	//
+	// Since many providers only support RS256, SupportedSigningAlgs defaults to this value.
+	SupportedSigningAlgs []string
+
+	// If true, no ClientID check performed. Must be true if ClientID field is empty.
+	SkipClientIDCheck bool
+	// If true, token expiry is not checked.
+	SkipExpiryCheck bool
+
+	// Time function to check Token expiry. Defaults to time.Now
+	Now func() time.Time
+}
+
+// Verifier returns an IDTokenVerifier that uses the provider's key set to verify JWTs.
+//
+// The returned IDTokenVerifier is tied to the Provider's context and its behavior is
+// undefined once the Provider's context is canceled.
+func (p *Provider) Verifier(config *Config) *IDTokenVerifier {
+	return NewVerifier(p.issuer, p.remoteKeySet, config)
+}
+
+func parseJWT(p string) ([]byte, error) {
+	parts := strings.Split(p, ".")
+	if len(parts) < 2 {
+		return nil, fmt.Errorf("oidc: malformed jwt, expected 3 parts got %d", len(parts))
+	}
+	payload, err := base64.RawURLEncoding.DecodeString(parts[1])
+	if err != nil {
+		return nil, fmt.Errorf("oidc: malformed jwt payload: %v", err)
+	}
+	return payload, nil
+}
+
+func contains(sli []string, ele string) bool {
+	for _, s := range sli {
+		if s == ele {
+			return true
+		}
+	}
+	return false
+}
+
+// Verify parses a raw ID Token, verifies it's been signed by the provider, preforms
+// any additional checks depending on the Config, and returns the payload.
+//
+// Verify does NOT do nonce validation, which is the callers responsibility.
+//
+// See: https://openid.net/specs/openid-connect-core-1_0.html#IDTokenValidation
+//
+//    oauth2Token, err := oauth2Config.Exchange(ctx, r.URL.Query().Get("code"))
+//    if err != nil {
+//        // handle error
+//    }
+//
+//    // Extract the ID Token from oauth2 token.
+//    rawIDToken, ok := oauth2Token.Extra("id_token").(string)
+//    if !ok {
+//        // handle error
+//    }
+//
+//    token, err := verifier.Verify(ctx, rawIDToken)
+//
+func (v *IDTokenVerifier) Verify(ctx context.Context, rawIDToken string) (*IDToken, error) {
+	jws, err := jose.ParseSigned(rawIDToken)
+	if err != nil {
+		return nil, fmt.Errorf("oidc: malformed jwt: %v", err)
+	}
+
+	// Throw out tokens with invalid claims before trying to verify the token. This lets
+	// us do cheap checks before possibly re-syncing keys.
+	payload, err := parseJWT(rawIDToken)
+	if err != nil {
+		return nil, fmt.Errorf("oidc: malformed jwt: %v", err)
+	}
+	var token idToken
+	if err := json.Unmarshal(payload, &token); err != nil {
+		return nil, fmt.Errorf("oidc: failed to unmarshal claims: %v", err)
+	}
+
+	t := &IDToken{
+		Issuer:          token.Issuer,
+		Subject:         token.Subject,
+		Audience:        []string(token.Audience),
+		Expiry:          time.Time(token.Expiry),
+		IssuedAt:        time.Time(token.IssuedAt),
+		Nonce:           token.Nonce,
+		AccessTokenHash: token.AtHash,
+		claims:          payload,
+	}
+
+	// Check issuer.
+	if t.Issuer != v.issuer {
+		// Google sometimes returns "accounts.google.com" as the issuer claim instead of
+		// the required "https://accounts.google.com". Detect this case and allow it only
+		// for Google.
+		//
+		// We will not add hooks to let other providers go off spec like this.
+		if !(v.issuer == issuerGoogleAccounts && t.Issuer == issuerGoogleAccountsNoScheme) {
+			return nil, fmt.Errorf("oidc: id token issued by a different provider, expected %q got %q", v.issuer, t.Issuer)
+		}
+	}
+
+	// If a client ID has been provided, make sure it's part of the audience. SkipClientIDCheck must be true if ClientID is empty.
+	//
+	// This check DOES NOT ensure that the ClientID is the party to which the ID Token was issued (i.e. Authorized party).
+	if !v.config.SkipClientIDCheck {
+		if v.config.ClientID != "" {
+			if !contains(t.Audience, v.config.ClientID) {
+				return nil, fmt.Errorf("oidc: expected audience %q got %q", v.config.ClientID, t.Audience)
+			}
+		} else {
+			return nil, fmt.Errorf("oidc: invalid configuration, clientID must be provided or SkipClientIDCheck must be set")
+		}
+	}
+
+	// If a SkipExpiryCheck is false, make sure token is not expired.
+	if !v.config.SkipExpiryCheck {
+		now := time.Now
+		if v.config.Now != nil {
+			now = v.config.Now
+		}
+
+		if t.Expiry.Before(now()) {
+			return nil, fmt.Errorf("oidc: token is expired (Token Expiry: %v)", t.Expiry)
+		}
+	}
+
+	switch len(jws.Signatures) {
+	case 0:
+		return nil, fmt.Errorf("oidc: id token not signed")
+	case 1:
+	default:
+		return nil, fmt.Errorf("oidc: multiple signatures on id token not supported")
+	}
+
+	sig := jws.Signatures[0]
+	supportedSigAlgs := v.config.SupportedSigningAlgs
+	if len(supportedSigAlgs) == 0 {
+		supportedSigAlgs = []string{RS256}
+	}
+
+	if !contains(supportedSigAlgs, sig.Header.Algorithm) {
+		return nil, fmt.Errorf("oidc: id token signed with unsupported algorithm, expected %q got %q", supportedSigAlgs, sig.Header.Algorithm)
+	}
+
+	t.sigAlgorithm = sig.Header.Algorithm
+
+	gotPayload, err := v.keySet.VerifySignature(ctx, rawIDToken)
+	if err != nil {
+		return nil, fmt.Errorf("failed to verify signature: %v", err)
+	}
+
+	// Ensure that the payload returned by the square actually matches the payload parsed earlier.
+	if !bytes.Equal(gotPayload, payload) {
+		return nil, errors.New("oidc: internal error, payload parsed did not match previous payload")
+	}
+
+	return t, nil
+}
+
+// Nonce returns an auth code option which requires the ID Token created by the
+// OpenID Connect provider to contain the specified nonce.
+func Nonce(nonce string) oauth2.AuthCodeOption {
+	return oauth2.SetAuthURLParam("nonce", nonce)
+}

src/vendor/github.com/pquerna/cachecontrol/.travis.yml

@@ -0,0 +1,10 @@
+language: go
+
+install:
+  - go get -d -v ./...
+  - go get -u github.com/stretchr/testify/require
+
+go:
+  - 1.7
+  - 1.8
+  - tip

src/vendor/github.com/pquerna/cachecontrol/LICENSE

@@ -0,0 +1,202 @@
+
+                                 Apache License
+                           Version 2.0, January 2004
+                        http://www.apache.org/licenses/
+
+   TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION
+
+   1. Definitions.
+
+      "License" shall mean the terms and conditions for use, reproduction,
+      and distribution as defined by Sections 1 through 9 of this document.
+
+      "Licensor" shall mean the copyright owner or entity authorized by
+      the copyright owner that is granting the License.
+
+      "Legal Entity" shall mean the union of the acting entity and all
+      other entities that control, are controlled by, or are under common
+      control with that entity. For the purposes of this definition,
+      "control" means (i) the power, direct or indirect, to cause the
+      direction or management of such entity, whether by contract or
+      otherwise, or (ii) ownership of fifty percent (50%) or more of the
+      outstanding shares, or (iii) beneficial ownership of such entity.
+
+      "You" (or "Your") shall mean an individual or Legal Entity
+      exercising permissions granted by this License.
+
+      "Source" form shall mean the preferred form for making modifications,
+      including but not limited to software source code, documentation
+      source, and configuration files.
+
+      "Object" form shall mean any form resulting from mechanical
+      transformation or translation of a Source form, including but
+      not limited to compiled object code, generated documentation,
+      and conversions to other media types.
+
+      "Work" shall mean the work of authorship, whether in Source or
+      Object form, made available under the License, as indicated by a
+      copyright notice that is included in or attached to the work
+      (an example is provided in the Appendix below).
+
+      "Derivative Works" shall mean any work, whether in Source or Object
+      form, that is based on (or derived from) the Work and for which the
+      editorial revisions, annotations, elaborations, or other modifications
+      represent, as a whole, an original work of authorship. For the purposes
+      of this License, Derivative Works shall not include works that remain
+      separable from, or merely link (or bind by name) to the interfaces of,
+      the Work and Derivative Works thereof.
+
+      "Contribution" shall mean any work of authorship, including
+      the original version of the Work and any modifications or additions
+      to that Work or Derivative Works thereof, that is intentionally
+      submitted to Licensor for inclusion in the Work by the copyright owner
+      or by an individual or Legal Entity authorized to submit on behalf of
+      the copyright owner. For the purposes of this definition, "submitted"
+      means any form of electronic, verbal, or written communication sent
+      to the Licensor or its representatives, including but not limited to
+      communication on electronic mailing lists, source code control systems,
+      and issue tracking systems that are managed by, or on behalf of, the
+      Licensor for the purpose of discussing and improving the Work, but
+      excluding communication that is conspicuously marked or otherwise
+      designated in writing by the copyright owner as "Not a Contribution."
+
+      "Contributor" shall mean Licensor and any individual or Legal Entity
+      on behalf of whom a Contribution has been received by Licensor and
+      subsequently incorporated within the Work.
+
+   2. Grant of Copyright License. Subject to the terms and conditions of
+      this License, each Contributor hereby grants to You a perpetual,
+      worldwide, non-exclusive, no-charge, royalty-free, irrevocable
+      copyright license to reproduce, prepare Derivative Works of,
+      publicly display, publicly perform, sublicense, and distribute the
+      Work and such Derivative Works in Source or Object form.
+
+   3. Grant of Patent License. Subject to the terms and conditions of
+      this License, each Contributor hereby grants to You a perpetual,
+      worldwide, non-exclusive, no-charge, royalty-free, irrevocable
+      (except as stated in this section) patent license to make, have made,
+      use, offer to sell, sell, import, and otherwise transfer the Work,
+      where such license applies only to those patent claims licensable
+      by such Contributor that are necessarily infringed by their
+      Contribution(s) alone or by combination of their Contribution(s)
+      with the Work to which such Contribution(s) was submitted. If You
+      institute patent litigation against any entity (including a
+      cross-claim or counterclaim in a lawsuit) alleging that the Work
+      or a Contribution incorporated within the Work constitutes direct
+      or contributory patent infringement, then any patent licenses
+      granted to You under this License for that Work shall terminate
+      as of the date such litigation is filed.
+
+   4. Redistribution. You may reproduce and distribute copies of the
+      Work or Derivative Works thereof in any medium, with or without
+      modifications, and in Source or Object form, provided that You
+      meet the following conditions:
+
+      (a) You must give any other recipients of the Work or
+          Derivative Works a copy of this License; and
+
+      (b) You must cause any modified files to carry prominent notices
+          stating that You changed the files; and
+
+      (c) You must retain, in the Source form of any Derivative Works
+          that You distribute, all copyright, patent, trademark, and
+          attribution notices from the Source form of the Work,
+          excluding those notices that do not pertain to any part of
+          the Derivative Works; and
+
+      (d) If the Work includes a "NOTICE" text file as part of its
+          distribution, then any Derivative Works that You distribute must
+          include a readable copy of the attribution notices contained
+          within such NOTICE file, excluding those notices that do not
+          pertain to any part of the Derivative Works, in at least one
+          of the following places: within a NOTICE text file distributed
+          as part of the Derivative Works; within the Source form or
+          documentation, if provided along with the Derivative Works; or,
+          within a display generated by the Derivative Works, if and
+          wherever such third-party notices normally appear. The contents
+          of the NOTICE file are for informational purposes only and
+          do not modify the License. You may add Your own attribution
+          notices within Derivative Works that You distribute, alongside
+          or as an addendum to the NOTICE text from the Work, provided
+          that such additional attribution notices cannot be construed
+          as modifying the License.
+
+      You may add Your own copyright statement to Your modifications and
+      may provide additional or different license terms and conditions
+      for use, reproduction, or distribution of Your modifications, or
+      for any such Derivative Works as a whole, provided Your use,
+      reproduction, and distribution of the Work otherwise complies with
+      the conditions stated in this License.
+
+   5. Submission of Contributions. Unless You explicitly state otherwise,
+      any Contribution intentionally submitted for inclusion in the Work
+      by You to the Licensor shall be under the terms and conditions of
+      this License, without any additional terms or conditions.
+      Notwithstanding the above, nothing herein shall supersede or modify
+      the terms of any separate license agreement you may have executed
+      with Licensor regarding such Contributions.
+
+   6. Trademarks. This License does not grant permission to use the trade
+      names, trademarks, service marks, or product names of the Licensor,
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+
+   7. Disclaimer of Warranty. Unless required by applicable law or
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+      Contributor provides its Contributions) on an "AS IS" BASIS,
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+      appropriateness of using or redistributing the Work and assume any
+      risks associated with Your exercise of permissions under this License.
+
+   8. Limitation of Liability. In no event and under no legal theory,
+      whether in tort (including negligence), contract, or otherwise,
+      unless required by applicable law (such as deliberate and grossly
+      negligent acts) or agreed to in writing, shall any Contributor be
+      liable to You for damages, including any direct, indirect, special,
+      incidental, or consequential damages of any character arising as a
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+      Work (including but not limited to damages for loss of goodwill,
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+      or other liability obligations and/or rights consistent with this
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+      on Your own behalf and on Your sole responsibility, not on behalf
+      of any other Contributor, and only if You agree to indemnify,
+      defend, and hold each Contributor harmless for any liability
+      incurred by, or claims asserted against, such Contributor by reason
+      of your accepting any such warranty or additional liability.
+
+   END OF TERMS AND CONDITIONS
+
+   APPENDIX: How to apply the Apache License to your work.
+
+      To apply the Apache License to your work, attach the following
+      boilerplate notice, with the fields enclosed by brackets "[]"
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+      file or class name and description of purpose be included on the
+      same "printed page" as the copyright notice for easier
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+
+   Copyright [yyyy] [name of copyright owner]
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+   Licensed under the Apache License, Version 2.0 (the "License");
+   you may not use this file except in compliance with the License.
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+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
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+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.

src/vendor/github.com/pquerna/cachecontrol/README.md

@@ -0,0 +1,107 @@
+# cachecontrol: HTTP Caching Parser and Interpretation
+
+[![GoDoc](https://godoc.org/github.com/pquerna/cachecontrol?status.svg)](https://godoc.org/github.com/pquerna/cachecontrol)[![Build Status](https://travis-ci.org/pquerna/cachecontrol.svg?branch=master)](https://travis-ci.org/pquerna/cachecontrol)
+
+ 
+
+`cachecontrol` implements [RFC 7234](http://tools.ietf.org/html/rfc7234) __Hypertext Transfer Protocol (HTTP/1.1): Caching__.  It does this by parsing the `Cache-Control` and other headers, providing information about requests and responses -- but `cachecontrol` does not implement an actual cache backend, just the control plane to make decisions about if a particular response is cachable.
+
+# Usage
+
+`cachecontrol.CachableResponse` returns an array of [reasons](https://godoc.org/github.com/pquerna/cachecontrol/cacheobject#Reason) why a response should not be cached and when it expires.  In the case that `len(reasons) == 0`, the response is cachable according to the RFC.  However, some people want non-compliant caches for various business use cases, so each reason is specifically named, so if your cache wants to cache `POST` requests, it can easily do that, but still be RFC compliant in other situations.
+
+# Examples
+
+## Can you cache Example.com?
+
+```go
+package main
+
+import (
+	"github.com/pquerna/cachecontrol"
+
+	"fmt"
+	"io/ioutil"
+	"net/http"
+)
+
+func main() {
+	req, _ := http.NewRequest("GET", "http://www.example.com/", nil)
+
+	res, _ := http.DefaultClient.Do(req)
+	_, _ = ioutil.ReadAll(res.Body)
+
+	reasons, expires, _ := cachecontrol.CachableResponse(req, res, cachecontrol.Options{})
+
+	fmt.Println("Reasons to not cache: ", reasons)
+	fmt.Println("Expiration: ", expires.String())
+}
+```
+
+## Can I use this in a high performance caching server?
+
+`cachecontrol` is divided into two packages: `cachecontrol` with a high level API, and a lower level `cacheobject` package.  Use [Object](https://godoc.org/github.com/pquerna/cachecontrol/cacheobject#Object) in a high performance use case where you have previously parsed headers containing dates or would like to avoid memory allocations.
+
+```go
+package main
+
+import (
+	"github.com/pquerna/cachecontrol/cacheobject"
+
+	"fmt"
+	"io/ioutil"
+	"net/http"
+)
+
+func main() {
+	req, _ := http.NewRequest("GET", "http://www.example.com/", nil)
+
+	res, _ := http.DefaultClient.Do(req)
+	_, _ = ioutil.ReadAll(res.Body)
+
+	reqDir, _ := cacheobject.ParseRequestCacheControl(req.Header.Get("Cache-Control"))
+
+	resDir, _ := cacheobject.ParseResponseCacheControl(res.Header.Get("Cache-Control"))
+	expiresHeader, _ := http.ParseTime(res.Header.Get("Expires"))
+	dateHeader, _ := http.ParseTime(res.Header.Get("Date"))
+	lastModifiedHeader, _ := http.ParseTime(res.Header.Get("Last-Modified"))
+
+	obj := cacheobject.Object{
+		RespDirectives:         resDir,
+		RespHeaders:            res.Header,
+		RespStatusCode:         res.StatusCode,
+		RespExpiresHeader:      expiresHeader,
+		RespDateHeader:         dateHeader,
+		RespLastModifiedHeader: lastModifiedHeader,
+
+		ReqDirectives: reqDir,
+		ReqHeaders:    req.Header,
+		ReqMethod:     req.Method,
+
+		NowUTC: time.Now().UTC(),
+	}
+	rv := cacheobject.ObjectResults{}
+
+	cacheobject.CachableObject(&obj, &rv)
+	cacheobject.ExpirationObject(&obj, &rv)
+
+	fmt.Println("Errors: ", rv.OutErr)
+	fmt.Println("Reasons to not cache: ", rv.OutReasons)
+	fmt.Println("Warning headers to add: ", rv.OutWarnings)
+	fmt.Println("Expiration: ", rv.OutExpirationTime.String())
+}
+```
+
+## Improvements, bugs, adding features, and taking cachecontrol new directions!
+
+Please [open issues in Github](https://github.com/pquerna/cachecontrol/issues) for ideas, bugs, and general thoughts.  Pull requests are of course preferred :)
+
+# Credits
+
+`cachecontrol` has recieved significant contributions from:
+
+* [Paul Querna](https://github.com/pquerna) 
+
+## License
+
+`cachecontrol` is licensed under the [Apache License, Version 2.0](./LICENSE)

src/vendor/github.com/pquerna/cachecontrol/api.go

@@ -0,0 +1,48 @@
+/**
+ *  Copyright 2015 Paul Querna
+ *
+ *  Licensed under the Apache License, Version 2.0 (the "License");
+ *  you may not use this file except in compliance with the License.
+ *  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ *
+ */
+
+package cachecontrol
+
+import (
+	"github.com/pquerna/cachecontrol/cacheobject"
+
+	"net/http"
+	"time"
+)
+
+type Options struct {
+	// Set to True for a prviate cache, which is not shared amoung users (eg, in a browser)
+	// Set to False for a "shared" cache, which is more common in a server context.
+	PrivateCache bool
+}
+
+// Given an HTTP Request, the future Status Code, and an ResponseWriter,
+// determine the possible reasons a response SHOULD NOT be cached.
+func CachableResponseWriter(req *http.Request,
+	statusCode int,
+	resp http.ResponseWriter,
+	opts Options) ([]cacheobject.Reason, time.Time, error) {
+	return cacheobject.UsingRequestResponse(req, statusCode, resp.Header(), opts.PrivateCache)
+}
+
+// Given an HTTP Request and Response, determine the possible reasons a response SHOULD NOT
+// be cached.
+func CachableResponse(req *http.Request,
+	resp *http.Response,
+	opts Options) ([]cacheobject.Reason, time.Time, error) {
+	return cacheobject.UsingRequestResponse(req, resp.StatusCode, resp.Header, opts.PrivateCache)
+}

src/vendor/github.com/pquerna/cachecontrol/cacheobject/directive.go

@@ -0,0 +1,546 @@
+/**
+ *  Copyright 2015 Paul Querna
+ *
+ *  Licensed under the Apache License, Version 2.0 (the "License");
+ *  you may not use this file except in compliance with the License.
+ *  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ *
+ */
+
+package cacheobject
+
+import (
+	"errors"
+	"math"
+	"net/http"
+	"net/textproto"
+	"strconv"
+	"strings"
+)
+
+// TODO(pquerna): add extensions from here: http://www.iana.org/assignments/http-cache-directives/http-cache-directives.xhtml
+
+var (
+	ErrQuoteMismatch         = errors.New("Missing closing quote")
+	ErrMaxAgeDeltaSeconds    = errors.New("Failed to parse delta-seconds in `max-age`")
+	ErrSMaxAgeDeltaSeconds   = errors.New("Failed to parse delta-seconds in `s-maxage`")
+	ErrMaxStaleDeltaSeconds  = errors.New("Failed to parse delta-seconds in `min-fresh`")
+	ErrMinFreshDeltaSeconds  = errors.New("Failed to parse delta-seconds in `min-fresh`")
+	ErrNoCacheNoArgs         = errors.New("Unexpected argument to `no-cache`")
+	ErrNoStoreNoArgs         = errors.New("Unexpected argument to `no-store`")
+	ErrNoTransformNoArgs     = errors.New("Unexpected argument to `no-transform`")
+	ErrOnlyIfCachedNoArgs    = errors.New("Unexpected argument to `only-if-cached`")
+	ErrMustRevalidateNoArgs  = errors.New("Unexpected argument to `must-revalidate`")
+	ErrPublicNoArgs          = errors.New("Unexpected argument to `public`")
+	ErrProxyRevalidateNoArgs = errors.New("Unexpected argument to `proxy-revalidate`")
+	// Experimental
+	ErrImmutableNoArgs                  = errors.New("Unexpected argument to `immutable`")
+	ErrStaleIfErrorDeltaSeconds         = errors.New("Failed to parse delta-seconds in `stale-if-error`")
+	ErrStaleWhileRevalidateDeltaSeconds = errors.New("Failed to parse delta-seconds in `stale-while-revalidate`")
+)
+
+func whitespace(b byte) bool {
+	if b == '\t' || b == ' ' {
+		return true
+	}
+	return false
+}
+
+func parse(value string, cd cacheDirective) error {
+	var err error = nil
+	i := 0
+
+	for i < len(value) && err == nil {
+		// eat leading whitespace or commas
+		if whitespace(value[i]) || value[i] == ',' {
+			i++
+			continue
+		}
+
+		j := i + 1
+
+		for j < len(value) {
+			if !isToken(value[j]) {
+				break
+			}
+			j++
+		}
+
+		token := strings.ToLower(value[i:j])
+		tokenHasFields := hasFieldNames(token)
+		/*
+			println("GOT TOKEN:")
+			println("	i -> ", i)
+			println("	j -> ", j)
+			println("	token -> ", token)
+		*/
+
+		if j+1 < len(value) && value[j] == '=' {
+			k := j + 1
+			// minimum size two bytes of "", but we let httpUnquote handle it.
+			if k < len(value) && value[k] == '"' {
+				eaten, result := httpUnquote(value[k:])
+				if eaten == -1 {
+					return ErrQuoteMismatch
+				}
+				i = k + eaten
+
+				err = cd.addPair(token, result)
+			} else {
+				z := k
+				for z < len(value) {
+					if tokenHasFields {
+						if whitespace(value[z]) {
+							break
+						}
+					} else {
+						if whitespace(value[z]) || value[z] == ',' {
+							break
+						}
+					}
+					z++
+				}
+				i = z
+
+				result := value[k:z]
+				if result != "" && result[len(result)-1] == ',' {
+					result = result[:len(result)-1]
+				}
+
+				err = cd.addPair(token, result)
+			}
+		} else {
+			if token != "," {
+				err = cd.addToken(token)
+			}
+			i = j
+		}
+	}
+
+	return err
+}
+
+// DeltaSeconds specifies a non-negative integer, representing
+// time in seconds: http://tools.ietf.org/html/rfc7234#section-1.2.1
+//
+// When set to -1, this means unset.
+//
+type DeltaSeconds int32
+
+// Parser for delta-seconds, a uint31, more or less:
+// http://tools.ietf.org/html/rfc7234#section-1.2.1
+func parseDeltaSeconds(v string) (DeltaSeconds, error) {
+	n, err := strconv.ParseUint(v, 10, 32)
+	if err != nil {
+		if numError, ok := err.(*strconv.NumError); ok {
+			if numError.Err == strconv.ErrRange {
+				return DeltaSeconds(math.MaxInt32), nil
+			}
+		}
+		return DeltaSeconds(-1), err
+	} else {
+		if n > math.MaxInt32 {
+			return DeltaSeconds(math.MaxInt32), nil
+		} else {
+			return DeltaSeconds(n), nil
+		}
+	}
+}
+
+// Fields present in a header.
+type FieldNames map[string]bool
+
+// internal interface for shared methods of RequestCacheDirectives and ResponseCacheDirectives
+type cacheDirective interface {
+	addToken(s string) error
+	addPair(s string, v string) error
+}
+
+// LOW LEVEL API: Repersentation of possible request directives in a `Cache-Control` header: http://tools.ietf.org/html/rfc7234#section-5.2.1
+//
+// Note: Many fields will be `nil` in practice.
+//
+type RequestCacheDirectives struct {
+
+	// max-age(delta seconds): http://tools.ietf.org/html/rfc7234#section-5.2.1.1
+	//
+	// The "max-age" request directive indicates that the client is
+	// unwilling to accept a response whose age is greater than the
+	// specified number of seconds.  Unless the max-stale request directive
+	// is also present, the client is not willing to accept a stale
+	// response.
+	MaxAge DeltaSeconds
+
+	// max-stale(delta seconds): http://tools.ietf.org/html/rfc7234#section-5.2.1.2
+	//
+	// The "max-stale" request directive indicates that the client is
+	// willing to accept a response that has exceeded its freshness
+	// lifetime.  If max-stale is assigned a value, then the client is
+	// willing to accept a response that has exceeded its freshness lifetime
+	// by no more than the specified number of seconds.  If no value is
+	// assigned to max-stale, then the client is willing to accept a stale
+	// response of any age.
+	MaxStale DeltaSeconds
+
+	// min-fresh(delta seconds): http://tools.ietf.org/html/rfc7234#section-5.2.1.3
+	//
+	// The "min-fresh" request directive indicates that the client is
+	// willing to accept a response whose freshness lifetime is no less than
+	// its current age plus the specified time in seconds.  That is, the
+	// client wants a response that will still be fresh for at least the
+	// specified number of seconds.
+	MinFresh DeltaSeconds
+
+	// no-cache(bool): http://tools.ietf.org/html/rfc7234#section-5.2.1.4
+	//
+	// The "no-cache" request directive indicates that a cache MUST NOT use
+	// a stored response to satisfy the request without successful
+	// validation on the origin server.
+	NoCache bool
+
+	// no-store(bool): http://tools.ietf.org/html/rfc7234#section-5.2.1.5
+	//
+	// The "no-store" request directive indicates that a cache MUST NOT
+	// store any part of either this request or any response to it.  This
+	// directive applies to both private and shared caches.
+	NoStore bool
+
+	// no-transform(bool): http://tools.ietf.org/html/rfc7234#section-5.2.1.6
+	//
+	// The "no-transform" request directive indicates that an intermediary
+	// (whether or not it implements a cache) MUST NOT transform the
+	// payload, as defined in Section 5.7.2 of RFC7230.
+	NoTransform bool
+
+	// only-if-cached(bool): http://tools.ietf.org/html/rfc7234#section-5.2.1.7
+	//
+	// The "only-if-cached" request directive indicates that the client only
+	// wishes to obtain a stored response.
+	OnlyIfCached bool
+
+	// Extensions: http://tools.ietf.org/html/rfc7234#section-5.2.3
+	//
+	// The Cache-Control header field can be extended through the use of one
+	// or more cache-extension tokens, each with an optional value.  A cache
+	// MUST ignore unrecognized cache directives.
+	Extensions []string
+}
+
+func (cd *RequestCacheDirectives) addToken(token string) error {
+	var err error = nil
+
+	switch token {
+	case "max-age":
+		err = ErrMaxAgeDeltaSeconds
+	case "max-stale":
+		err = ErrMaxStaleDeltaSeconds
+	case "min-fresh":
+		err = ErrMinFreshDeltaSeconds
+	case "no-cache":
+		cd.NoCache = true
+	case "no-store":
+		cd.NoStore = true
+	case "no-transform":
+		cd.NoTransform = true
+	case "only-if-cached":
+		cd.OnlyIfCached = true
+	default:
+		cd.Extensions = append(cd.Extensions, token)
+	}
+	return err
+}
+
+func (cd *RequestCacheDirectives) addPair(token string, v string) error {
+	var err error = nil
+
+	switch token {
+	case "max-age":
+		cd.MaxAge, err = parseDeltaSeconds(v)
+		if err != nil {
+			err = ErrMaxAgeDeltaSeconds
+		}
+	case "max-stale":
+		cd.MaxStale, err = parseDeltaSeconds(v)
+		if err != nil {
+			err = ErrMaxStaleDeltaSeconds
+		}
+	case "min-fresh":
+		cd.MinFresh, err = parseDeltaSeconds(v)
+		if err != nil {
+			err = ErrMinFreshDeltaSeconds
+		}
+	case "no-cache":
+		err = ErrNoCacheNoArgs
+	case "no-store":
+		err = ErrNoStoreNoArgs
+	case "no-transform":
+		err = ErrNoTransformNoArgs
+	case "only-if-cached":
+		err = ErrOnlyIfCachedNoArgs
+	default:
+		// TODO(pquerna): this sucks, making user re-parse
+		cd.Extensions = append(cd.Extensions, token+"="+v)
+	}
+
+	return err
+}
+
+// LOW LEVEL API: Parses a Cache Control Header from a Request into a set of directives.
+func ParseRequestCacheControl(value string) (*RequestCacheDirectives, error) {
+	cd := &RequestCacheDirectives{
+		MaxAge:   -1,
+		MaxStale: -1,
+		MinFresh: -1,
+	}
+
+	err := parse(value, cd)
+	if err != nil {
+		return nil, err
+	}
+	return cd, nil
+}
+
+// LOW LEVEL API: Repersentation of possible response directives in a `Cache-Control` header: http://tools.ietf.org/html/rfc7234#section-5.2.2
+//
+// Note: Many fields will be `nil` in practice.
+//
+type ResponseCacheDirectives struct {
+
+	// must-revalidate(bool): http://tools.ietf.org/html/rfc7234#section-5.2.2.1
+	//
+	// The "must-revalidate" response directive indicates that once it has
+	// become stale, a cache MUST NOT use the response to satisfy subsequent
+	// requests without successful validation on the origin server.
+	MustRevalidate bool
+
+	// no-cache(FieldName): http://tools.ietf.org/html/rfc7234#section-5.2.2.2
+	//
+	// The "no-cache" response directive indicates that the response MUST
+	// NOT be used to satisfy a subsequent request without successful
+	// validation on the origin server.
+	//
+	// If the no-cache response directive specifies one or more field-names,
+	// then a cache MAY use the response to satisfy a subsequent request,
+	// subject to any other restrictions on caching.  However, any header
+	// fields in the response that have the field-name(s) listed MUST NOT be
+	// sent in the response to a subsequent request without successful
+	// revalidation with the origin server.
+	NoCache FieldNames
+
+	// no-cache(cast-to-bool): http://tools.ietf.org/html/rfc7234#section-5.2.2.2
+	//
+	// While the RFC defines optional field-names on a no-cache directive,
+	// many applications only want to know if any no-cache directives were
+	// present at all.
+	NoCachePresent bool
+
+	// no-store(bool): http://tools.ietf.org/html/rfc7234#section-5.2.2.3
+	//
+	// The "no-store" request directive indicates that a cache MUST NOT
+	// store any part of either this request or any response to it.  This
+	// directive applies to both private and shared caches.
+	NoStore bool
+
+	// no-transform(bool): http://tools.ietf.org/html/rfc7234#section-5.2.2.4
+	//
+	// The "no-transform" response directive indicates that an intermediary
+	// (regardless of whether it implements a cache) MUST NOT transform the
+	// payload, as defined in Section 5.7.2 of RFC7230.
+	NoTransform bool
+
+	// public(bool): http://tools.ietf.org/html/rfc7234#section-5.2.2.5
+	//
+	// The "public" response directive indicates that any cache MAY store
+	// the response, even if the response would normally be non-cacheable or
+	// cacheable only within a private cache.
+	Public bool
+
+	// private(FieldName): http://tools.ietf.org/html/rfc7234#section-5.2.2.6
+	//
+	// The "private" response directive indicates that the response message
+	// is intended for a single user and MUST NOT be stored by a shared
+	// cache.  A private cache MAY store the response and reuse it for later
+	// requests, even if the response would normally be non-cacheable.
+	//
+	// If the private response directive specifies one or more field-names,
+	// this requirement is limited to the field-values associated with the
+	// listed response header fields.  That is, a shared cache MUST NOT
+	// store the specified field-names(s), whereas it MAY store the
+	// remainder of the response message.
+	Private FieldNames
+
+	// private(cast-to-bool): http://tools.ietf.org/html/rfc7234#section-5.2.2.6
+	//
+	// While the RFC defines optional field-names on a private directive,
+	// many applications only want to know if any private directives were
+	// present at all.
+	PrivatePresent bool
+
+	// proxy-revalidate(bool): http://tools.ietf.org/html/rfc7234#section-5.2.2.7
+	//
+	// The "proxy-revalidate" response directive has the same meaning as the
+	// must-revalidate response directive, except that it does not apply to
+	// private caches.
+	ProxyRevalidate bool
+
+	// max-age(delta seconds): http://tools.ietf.org/html/rfc7234#section-5.2.2.8
+	//
+	// The "max-age" response directive indicates that the response is to be
+	// considered stale after its age is greater than the specified number
+	// of seconds.
+	MaxAge DeltaSeconds
+
+	// s-maxage(delta seconds): http://tools.ietf.org/html/rfc7234#section-5.2.2.9
+	//
+	// The "s-maxage" response directive indicates that, in shared caches,
+	// the maximum age specified by this directive overrides the maximum age
+	// specified by either the max-age directive or the Expires header
+	// field.  The s-maxage directive also implies the semantics of the
+	// proxy-revalidate response directive.
+	SMaxAge DeltaSeconds
+
+	////
+	// Experimental features
+	// - https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Cache-Control#Extension_Cache-Control_directives
+	// - https://www.fastly.com/blog/stale-while-revalidate-stale-if-error-available-today
+	////
+
+	// immutable(cast-to-bool): experimental feature
+	Immutable bool
+
+	// stale-if-error(delta seconds): experimental feature
+	StaleIfError DeltaSeconds
+
+	// stale-while-revalidate(delta seconds): experimental feature
+	StaleWhileRevalidate DeltaSeconds
+
+	// Extensions: http://tools.ietf.org/html/rfc7234#section-5.2.3
+	//
+	// The Cache-Control header field can be extended through the use of one
+	// or more cache-extension tokens, each with an optional value.  A cache
+	// MUST ignore unrecognized cache directives.
+	Extensions []string
+}
+
+// LOW LEVEL API: Parses a Cache Control Header from a Response into a set of directives.
+func ParseResponseCacheControl(value string) (*ResponseCacheDirectives, error) {
+	cd := &ResponseCacheDirectives{
+		MaxAge:  -1,
+		SMaxAge: -1,
+		// Exerimantal stale timeouts
+		StaleIfError:         -1,
+		StaleWhileRevalidate: -1,
+	}
+
+	err := parse(value, cd)
+	if err != nil {
+		return nil, err
+	}
+	return cd, nil
+}
+
+func (cd *ResponseCacheDirectives) addToken(token string) error {
+	var err error = nil
+	switch token {
+	case "must-revalidate":
+		cd.MustRevalidate = true
+	case "no-cache":
+		cd.NoCachePresent = true
+	case "no-store":
+		cd.NoStore = true
+	case "no-transform":
+		cd.NoTransform = true
+	case "public":
+		cd.Public = true
+	case "private":
+		cd.PrivatePresent = true
+	case "proxy-revalidate":
+		cd.ProxyRevalidate = true
+	case "max-age":
+		err = ErrMaxAgeDeltaSeconds
+	case "s-maxage":
+		err = ErrSMaxAgeDeltaSeconds
+	// Experimental
+	case "immutable":
+		cd.Immutable = true
+	case "stale-if-error":
+		err = ErrMaxAgeDeltaSeconds
+	case "stale-while-revalidate":
+		err = ErrMaxAgeDeltaSeconds
+	default:
+		cd.Extensions = append(cd.Extensions, token)
+	}
+	return err
+}
+
+func hasFieldNames(token string) bool {
+	switch token {
+	case "no-cache":
+		return true
+	case "private":
+		return true
+	}
+	return false
+}
+
+func (cd *ResponseCacheDirectives) addPair(token string, v string) error {
+	var err error = nil
+
+	switch token {
+	case "must-revalidate":
+		err = ErrMustRevalidateNoArgs
+	case "no-cache":
+		cd.NoCachePresent = true
+		tokens := strings.Split(v, ",")
+		if cd.NoCache == nil {
+			cd.NoCache = make(FieldNames)
+		}
+		for _, t := range tokens {
+			k := http.CanonicalHeaderKey(textproto.TrimString(t))
+			cd.NoCache[k] = true
+		}
+	case "no-store":
+		err = ErrNoStoreNoArgs
+	case "no-transform":
+		err = ErrNoTransformNoArgs
+	case "public":
+		err = ErrPublicNoArgs
+	case "private":
+		cd.PrivatePresent = true
+		tokens := strings.Split(v, ",")
+		if cd.Private == nil {
+			cd.Private = make(FieldNames)
+		}
+		for _, t := range tokens {
+			k := http.CanonicalHeaderKey(textproto.TrimString(t))
+			cd.Private[k] = true
+		}
+	case "proxy-revalidate":
+		err = ErrProxyRevalidateNoArgs
+	case "max-age":
+		cd.MaxAge, err = parseDeltaSeconds(v)
+	case "s-maxage":
+		cd.SMaxAge, err = parseDeltaSeconds(v)
+	// Experimental
+	case "immutable":
+		err = ErrImmutableNoArgs
+	case "stale-if-error":
+		cd.StaleIfError, err = parseDeltaSeconds(v)
+	case "stale-while-revalidate":
+		cd.StaleWhileRevalidate, err = parseDeltaSeconds(v)
+	default:
+		// TODO(pquerna): this sucks, making user re-parse, and its technically not 'quoted' like the original,
+		// but this is still easier, just a SplitN on "="
+		cd.Extensions = append(cd.Extensions, token+"="+v)
+	}
+
+	return err
+}

src/vendor/github.com/pquerna/cachecontrol/cacheobject/lex.go

@@ -0,0 +1,93 @@
+// Copyright 2009 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package cacheobject
+
+// This file deals with lexical matters of HTTP
+
+func isSeparator(c byte) bool {
+	switch c {
+	case '(', ')', '<', '>', '@', ',', ';', ':', '\\', '"', '/', '[', ']', '?', '=', '{', '}', ' ', '\t':
+		return true
+	}
+	return false
+}
+
+func isCtl(c byte) bool { return (0 <= c && c <= 31) || c == 127 }
+
+func isChar(c byte) bool { return 0 <= c && c <= 127 }
+
+func isAnyText(c byte) bool { return !isCtl(c) }
+
+func isQdText(c byte) bool { return isAnyText(c) && c != '"' }
+
+func isToken(c byte) bool { return isChar(c) && !isCtl(c) && !isSeparator(c) }
+
+// Valid escaped sequences are not specified in RFC 2616, so for now, we assume
+// that they coincide with the common sense ones used by GO. Malformed
+// characters should probably not be treated as errors by a robust (forgiving)
+// parser, so we replace them with the '?' character.
+func httpUnquotePair(b byte) byte {
+	// skip the first byte, which should always be '\'
+	switch b {
+	case 'a':
+		return '\a'
+	case 'b':
+		return '\b'
+	case 'f':
+		return '\f'
+	case 'n':
+		return '\n'
+	case 'r':
+		return '\r'
+	case 't':
+		return '\t'
+	case 'v':
+		return '\v'
+	case '\\':
+		return '\\'
+	case '\'':
+		return '\''
+	case '"':
+		return '"'
+	}
+	return '?'
+}
+
+// raw must begin with a valid quoted string. Only the first quoted string is
+// parsed and is unquoted in result. eaten is the number of bytes parsed, or -1
+// upon failure.
+func httpUnquote(raw string) (eaten int, result string) {
+	buf := make([]byte, len(raw))
+	if raw[0] != '"' {
+		return -1, ""
+	}
+	eaten = 1
+	j := 0 // # of bytes written in buf
+	for i := 1; i < len(raw); i++ {
+		switch b := raw[i]; b {
+		case '"':
+			eaten++
+			buf = buf[0:j]
+			return i + 1, string(buf)
+		case '\\':
+			if len(raw) < i+2 {
+				return -1, ""
+			}
+			buf[j] = httpUnquotePair(raw[i+1])
+			eaten += 2
+			j++
+			i++
+		default:
+			if isQdText(b) {
+				buf[j] = b
+			} else {
+				buf[j] = '?'
+			}
+			eaten++
+			j++
+		}
+	}
+	return -1, ""
+}

src/vendor/github.com/pquerna/cachecontrol/cacheobject/object.go

@@ -0,0 +1,387 @@
+/**
+ *  Copyright 2015 Paul Querna
+ *
+ *  Licensed under the Apache License, Version 2.0 (the "License");
+ *  you may not use this file except in compliance with the License.
+ *  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ *
+ */
+
+package cacheobject
+
+import (
+	"net/http"
+	"time"
+)
+
+// LOW LEVEL API: Repersents a potentially cachable HTTP object.
+//
+// This struct is designed to be serialized efficiently, so in a high
+// performance caching server, things like Date-Strings don't need to be
+// parsed for every use of a cached object.
+type Object struct {
+	CacheIsPrivate bool
+
+	RespDirectives         *ResponseCacheDirectives
+	RespHeaders            http.Header
+	RespStatusCode         int
+	RespExpiresHeader      time.Time
+	RespDateHeader         time.Time
+	RespLastModifiedHeader time.Time
+
+	ReqDirectives *RequestCacheDirectives
+	ReqHeaders    http.Header
+	ReqMethod     string
+
+	NowUTC time.Time
+}
+
+// LOW LEVEL API: Repersents the results of examinig an Object with
+// CachableObject and ExpirationObject.
+//
+// TODO(pquerna): decide if this is a good idea or bad
+type ObjectResults struct {
+	OutReasons        []Reason
+	OutWarnings       []Warning
+	OutExpirationTime time.Time
+	OutErr            error
+}
+
+// LOW LEVEL API: Check if a object is cachable.
+func CachableObject(obj *Object, rv *ObjectResults) {
+	rv.OutReasons = nil
+	rv.OutWarnings = nil
+	rv.OutErr = nil
+
+	switch obj.ReqMethod {
+	case "GET":
+		break
+	case "HEAD":
+		break
+	case "POST":
+		/**
+		  POST: http://tools.ietf.org/html/rfc7231#section-4.3.3
+
+		  Responses to POST requests are only cacheable when they include
+		  explicit freshness information (see Section 4.2.1 of [RFC7234]).
+		  However, POST caching is not widely implemented.  For cases where an
+		  origin server wishes the client to be able to cache the result of a
+		  POST in a way that can be reused by a later GET, the origin server
+		  MAY send a 200 (OK) response containing the result and a
+		  Content-Location header field that has the same value as the POST's
+		  effective request URI (Section 3.1.4.2).
+		*/
+		if !hasFreshness(obj.ReqDirectives, obj.RespDirectives, obj.RespHeaders, obj.RespExpiresHeader, obj.CacheIsPrivate) {
+			rv.OutReasons = append(rv.OutReasons, ReasonRequestMethodPOST)
+		}
+
+	case "PUT":
+		rv.OutReasons = append(rv.OutReasons, ReasonRequestMethodPUT)
+
+	case "DELETE":
+		rv.OutReasons = append(rv.OutReasons, ReasonRequestMethodDELETE)
+
+	case "CONNECT":
+		rv.OutReasons = append(rv.OutReasons, ReasonRequestMethodCONNECT)
+
+	case "OPTIONS":
+		rv.OutReasons = append(rv.OutReasons, ReasonRequestMethodOPTIONS)
+
+	case "TRACE":
+		rv.OutReasons = append(rv.OutReasons, ReasonRequestMethodTRACE)
+
+	// HTTP Extension Methods: http://www.iana.org/assignments/http-methods/http-methods.xhtml
+	//
+	// To my knowledge, none of them are cachable. Please open a ticket if this is not the case!
+	//
+	default:
+		rv.OutReasons = append(rv.OutReasons, ReasonRequestMethodUnkown)
+	}
+
+	if obj.ReqDirectives.NoStore {
+		rv.OutReasons = append(rv.OutReasons, ReasonRequestNoStore)
+	}
+
+	// Storing Responses to Authenticated Requests: http://tools.ietf.org/html/rfc7234#section-3.2
+	authz := obj.ReqHeaders.Get("Authorization")
+	if authz != "" {
+		if obj.RespDirectives.MustRevalidate ||
+			obj.RespDirectives.Public ||
+			obj.RespDirectives.SMaxAge != -1 {
+			// Expires of some kind present, this is potentially OK.
+		} else {
+			rv.OutReasons = append(rv.OutReasons, ReasonRequestAuthorizationHeader)
+		}
+	}
+
+	if obj.RespDirectives.PrivatePresent && !obj.CacheIsPrivate {
+		rv.OutReasons = append(rv.OutReasons, ReasonResponsePrivate)
+	}
+
+	if obj.RespDirectives.NoStore {
+		rv.OutReasons = append(rv.OutReasons, ReasonResponseNoStore)
+	}
+
+	/*
+	   the response either:
+
+	     *  contains an Expires header field (see Section 5.3), or
+
+	     *  contains a max-age response directive (see Section 5.2.2.8), or
+
+	     *  contains a s-maxage response directive (see Section 5.2.2.9)
+	        and the cache is shared, or
+
+	     *  contains a Cache Control Extension (see Section 5.2.3) that
+	        allows it to be cached, or
+
+	     *  has a status code that is defined as cacheable by default (see
+	        Section 4.2.2), or
+
+	     *  contains a public response directive (see Section 5.2.2.5).
+	*/
+
+	expires := obj.RespHeaders.Get("Expires") != ""
+	statusCachable := cachableStatusCode(obj.RespStatusCode)
+
+	if expires ||
+		obj.RespDirectives.MaxAge != -1 ||
+		(obj.RespDirectives.SMaxAge != -1 && !obj.CacheIsPrivate) ||
+		statusCachable ||
+		obj.RespDirectives.Public {
+		/* cachable by default, at least one of the above conditions was true */
+	} else {
+		rv.OutReasons = append(rv.OutReasons, ReasonResponseUncachableByDefault)
+	}
+}
+
+var twentyFourHours = time.Duration(24 * time.Hour)
+
+const debug = false
+
+// LOW LEVEL API: Update an objects expiration time.
+func ExpirationObject(obj *Object, rv *ObjectResults) {
+	/**
+	 * Okay, lets calculate Freshness/Expiration now. woo:
+	 *  http://tools.ietf.org/html/rfc7234#section-4.2
+	 */
+
+	/*
+	   o  If the cache is shared and the s-maxage response directive
+	      (Section 5.2.2.9) is present, use its value, or
+
+	   o  If the max-age response directive (Section 5.2.2.8) is present,
+	      use its value, or
+
+	   o  If the Expires response header field (Section 5.3) is present, use
+	      its value minus the value of the Date response header field, or
+
+	   o  Otherwise, no explicit expiration time is present in the response.
+	      A heuristic freshness lifetime might be applicable; see
+	      Section 4.2.2.
+	*/
+
+	var expiresTime time.Time
+
+	if obj.RespDirectives.SMaxAge != -1 && !obj.CacheIsPrivate {
+		expiresTime = obj.NowUTC.Add(time.Second * time.Duration(obj.RespDirectives.SMaxAge))
+	} else if obj.RespDirectives.MaxAge != -1 {
+		expiresTime = obj.NowUTC.UTC().Add(time.Second * time.Duration(obj.RespDirectives.MaxAge))
+	} else if !obj.RespExpiresHeader.IsZero() {
+		serverDate := obj.RespDateHeader
+		if serverDate.IsZero() {
+			// common enough case when a Date: header has not yet been added to an
+			// active response.
+			serverDate = obj.NowUTC
+		}
+		expiresTime = obj.NowUTC.Add(obj.RespExpiresHeader.Sub(serverDate))
+	} else if !obj.RespLastModifiedHeader.IsZero() {
+		// heuristic freshness lifetime
+		rv.OutWarnings = append(rv.OutWarnings, WarningHeuristicExpiration)
+
+		// http://httpd.apache.org/docs/2.4/mod/mod_cache.html#cachelastmodifiedfactor
+		// CacheMaxExpire defaults to 24 hours
+		// CacheLastModifiedFactor: is 0.1
+		//
+		// expiry-period = MIN(time-since-last-modified-date * factor, 24 hours)
+		//
+		// obj.NowUTC
+
+		since := obj.RespLastModifiedHeader.Sub(obj.NowUTC)
+		since = time.Duration(float64(since) * -0.1)
+
+		if since > twentyFourHours {
+			expiresTime = obj.NowUTC.Add(twentyFourHours)
+		} else {
+			expiresTime = obj.NowUTC.Add(since)
+		}
+
+		if debug {
+			println("Now UTC: ", obj.NowUTC.String())
+			println("Last-Modified: ", obj.RespLastModifiedHeader.String())
+			println("Since: ", since.String())
+			println("TwentyFourHours: ", twentyFourHours.String())
+			println("Expiration: ", expiresTime.String())
+		}
+	} else {
+		// TODO(pquerna): what should the default behavoir be for expiration time?
+	}
+
+	rv.OutExpirationTime = expiresTime
+}
+
+// Evaluate cachability based on an HTTP request, and parts of the response.
+func UsingRequestResponse(req *http.Request,
+	statusCode int,
+	respHeaders http.Header,
+	privateCache bool) ([]Reason, time.Time, error) {
+	reasons, time, _, _, err := UsingRequestResponseWithObject(req, statusCode, respHeaders, privateCache)
+	return reasons, time, err
+}
+
+// Evaluate cachability based on an HTTP request, and parts of the response.
+// Returns the parsed Object as well.
+func UsingRequestResponseWithObject(req *http.Request,
+	statusCode int,
+	respHeaders http.Header,
+	privateCache bool) ([]Reason, time.Time, []Warning, *Object, error) {
+	var reqHeaders http.Header
+	var reqMethod string
+
+	var reqDir *RequestCacheDirectives = nil
+	respDir, err := ParseResponseCacheControl(respHeaders.Get("Cache-Control"))
+	if err != nil {
+		return nil, time.Time{}, nil, nil, err
+	}
+
+	if req != nil {
+		reqDir, err = ParseRequestCacheControl(req.Header.Get("Cache-Control"))
+		if err != nil {
+			return nil, time.Time{}, nil, nil, err
+		}
+		reqHeaders = req.Header
+		reqMethod = req.Method
+	}
+
+	var expiresHeader time.Time
+	var dateHeader time.Time
+	var lastModifiedHeader time.Time
+
+	if respHeaders.Get("Expires") != "" {
+		expiresHeader, err = http.ParseTime(respHeaders.Get("Expires"))
+		if err != nil {
+			// sometimes servers will return `Expires: 0` or `Expires: -1` to
+			// indicate expired content
+			expiresHeader = time.Time{}
+		}
+		expiresHeader = expiresHeader.UTC()
+	}
+
+	if respHeaders.Get("Date") != "" {
+		dateHeader, err = http.ParseTime(respHeaders.Get("Date"))
+		if err != nil {
+			return nil, time.Time{}, nil, nil, err
+		}
+		dateHeader = dateHeader.UTC()
+	}
+
+	if respHeaders.Get("Last-Modified") != "" {
+		lastModifiedHeader, err = http.ParseTime(respHeaders.Get("Last-Modified"))
+		if err != nil {
+			return nil, time.Time{}, nil, nil, err
+		}
+		lastModifiedHeader = lastModifiedHeader.UTC()
+	}
+
+	obj := Object{
+		CacheIsPrivate: privateCache,
+
+		RespDirectives:         respDir,
+		RespHeaders:            respHeaders,
+		RespStatusCode:         statusCode,
+		RespExpiresHeader:      expiresHeader,
+		RespDateHeader:         dateHeader,
+		RespLastModifiedHeader: lastModifiedHeader,
+
+		ReqDirectives: reqDir,
+		ReqHeaders:    reqHeaders,
+		ReqMethod:     reqMethod,
+
+		NowUTC: time.Now().UTC(),
+	}
+	rv := ObjectResults{}
+
+	CachableObject(&obj, &rv)
+	if rv.OutErr != nil {
+		return nil, time.Time{}, nil, nil, rv.OutErr
+	}
+
+	ExpirationObject(&obj, &rv)
+	if rv.OutErr != nil {
+		return nil, time.Time{}, nil, nil, rv.OutErr
+	}
+
+	return rv.OutReasons, rv.OutExpirationTime, rv.OutWarnings, &obj, nil
+}
+
+// calculate if a freshness directive is present: http://tools.ietf.org/html/rfc7234#section-4.2.1
+func hasFreshness(reqDir *RequestCacheDirectives, respDir *ResponseCacheDirectives, respHeaders http.Header, respExpires time.Time, privateCache bool) bool {
+	if !privateCache && respDir.SMaxAge != -1 {
+		return true
+	}
+
+	if respDir.MaxAge != -1 {
+		return true
+	}
+
+	if !respExpires.IsZero() || respHeaders.Get("Expires") != "" {
+		return true
+	}
+
+	return false
+}
+
+func cachableStatusCode(statusCode int) bool {
+	/*
+		Responses with status codes that are defined as cacheable by default
+		(e.g., 200, 203, 204, 206, 300, 301, 404, 405, 410, 414, and 501 in
+		this specification) can be reused by a cache with heuristic
+		expiration unless otherwise indicated by the method definition or
+		explicit cache controls [RFC7234]; all other status codes are not
+		cacheable by default.
+	*/
+	switch statusCode {
+	case 200:
+		return true
+	case 203:
+		return true
+	case 204:
+		return true
+	case 206:
+		return true
+	case 300:
+		return true
+	case 301:
+		return true
+	case 404:
+		return true
+	case 405:
+		return true
+	case 410:
+		return true
+	case 414:
+		return true
+	case 501:
+		return true
+	default:
+		return false
+	}
+}

src/vendor/github.com/pquerna/cachecontrol/cacheobject/reasons.go

@@ -0,0 +1,95 @@
+/**
+ *  Copyright 2015 Paul Querna
+ *
+ *  Licensed under the Apache License, Version 2.0 (the "License");
+ *  you may not use this file except in compliance with the License.
+ *  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ *
+ */
+
+package cacheobject
+
+// Repersents a potential Reason to not cache an object.
+//
+// Applications may wish to ignore specific reasons, which will make them non-RFC
+// compliant, but this type gives them specific cases they can choose to ignore,
+// making them compliant in as many cases as they can.
+type Reason int
+
+const (
+
+	// The request method was POST and an Expiration header was not supplied.
+	ReasonRequestMethodPOST Reason = iota
+
+	// The request method was PUT and PUTs are not cachable.
+	ReasonRequestMethodPUT
+
+	// The request method was DELETE and DELETEs are not cachable.
+	ReasonRequestMethodDELETE
+
+	// The request method was CONNECT and CONNECTs are not cachable.
+	ReasonRequestMethodCONNECT
+
+	// The request method was OPTIONS and OPTIONS are not cachable.
+	ReasonRequestMethodOPTIONS
+
+	// The request method was TRACE and TRACEs are not cachable.
+	ReasonRequestMethodTRACE
+
+	// The request method was not recognized by cachecontrol, and should not be cached.
+	ReasonRequestMethodUnkown
+
+	// The request included an Cache-Control: no-store header
+	ReasonRequestNoStore
+
+	// The request included an Authorization header without an explicit Public or Expiration time: http://tools.ietf.org/html/rfc7234#section-3.2
+	ReasonRequestAuthorizationHeader
+
+	// The response included an Cache-Control: no-store header
+	ReasonResponseNoStore
+
+	// The response included an Cache-Control: private header and this is not a Private cache
+	ReasonResponsePrivate
+
+	// The response failed to meet at least one of the conditions specified in RFC 7234 section 3: http://tools.ietf.org/html/rfc7234#section-3
+	ReasonResponseUncachableByDefault
+)
+
+func (r Reason) String() string {
+	switch r {
+	case ReasonRequestMethodPOST:
+		return "ReasonRequestMethodPOST"
+	case ReasonRequestMethodPUT:
+		return "ReasonRequestMethodPUT"
+	case ReasonRequestMethodDELETE:
+		return "ReasonRequestMethodDELETE"
+	case ReasonRequestMethodCONNECT:
+		return "ReasonRequestMethodCONNECT"
+	case ReasonRequestMethodOPTIONS:
+		return "ReasonRequestMethodOPTIONS"
+	case ReasonRequestMethodTRACE:
+		return "ReasonRequestMethodTRACE"
+	case ReasonRequestMethodUnkown:
+		return "ReasonRequestMethodUnkown"
+	case ReasonRequestNoStore:
+		return "ReasonRequestNoStore"
+	case ReasonRequestAuthorizationHeader:
+		return "ReasonRequestAuthorizationHeader"
+	case ReasonResponseNoStore:
+		return "ReasonResponseNoStore"
+	case ReasonResponsePrivate:
+		return "ReasonResponsePrivate"
+	case ReasonResponseUncachableByDefault:
+		return "ReasonResponseUncachableByDefault"
+	}
+
+	panic(r)
+}

src/vendor/github.com/pquerna/cachecontrol/cacheobject/warning.go

@@ -0,0 +1,107 @@
+/**
+ *  Copyright 2015 Paul Querna
+ *
+ *  Licensed under the Apache License, Version 2.0 (the "License");
+ *  you may not use this file except in compliance with the License.
+ *  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ *
+ */
+
+package cacheobject
+
+import (
+	"fmt"
+	"net/http"
+	"time"
+)
+
+// Repersents an HTTP Warning: http://tools.ietf.org/html/rfc7234#section-5.5
+type Warning int
+
+const (
+	// Response is Stale
+	// A cache SHOULD generate this whenever the sent response is stale.
+	WarningResponseIsStale Warning = 110
+
+	// Revalidation Failed
+	// A cache SHOULD generate this when sending a stale
+	// response because an attempt to validate the response failed, due to an
+	// inability to reach the server.
+	WarningRevalidationFailed Warning = 111
+
+	// Disconnected Operation
+	// A cache SHOULD generate this if it is intentionally disconnected from
+	// the rest of the network for a period of time.
+	WarningDisconnectedOperation Warning = 112
+
+	// Heuristic Expiration
+	//
+	// A cache SHOULD generate this if it heuristically chose a freshness
+	// lifetime greater than 24 hours and the response's age is greater than
+	// 24 hours.
+	WarningHeuristicExpiration Warning = 113
+
+	// Miscellaneous Warning
+	//
+	// The warning text can include arbitrary information to be presented to
+	// a human user or logged.  A system receiving this warning MUST NOT
+	// take any automated action, besides presenting the warning to the
+	// user.
+	WarningMiscellaneousWarning Warning = 199
+
+	// Transformation Applied
+	//
+	// This Warning code MUST be added by a proxy if it applies any
+	// transformation to the representation, such as changing the
+	// content-coding, media-type, or modifying the representation data,
+	// unless this Warning code already appears in the response.
+	WarningTransformationApplied Warning = 214
+
+	// Miscellaneous Persistent Warning
+	//
+	// The warning text can include arbitrary information to be presented to
+	// a human user or logged.  A system receiving this warning MUST NOT
+	// take any automated action.
+	WarningMiscellaneousPersistentWarning Warning = 299
+)
+
+func (w Warning) HeaderString(agent string, date time.Time) string {
+	if agent == "" {
+		agent = "-"
+	} else {
+		// TODO(pquerna): this doesn't escape agent if it contains bad things.
+		agent = `"` + agent + `"`
+	}
+	return fmt.Sprintf(`%d %s "%s" %s`, w, agent, w.String(), date.Format(http.TimeFormat))
+}
+
+func (w Warning) String() string {
+	switch w {
+	case WarningResponseIsStale:
+		return "Response is Stale"
+	case WarningRevalidationFailed:
+		return "Revalidation Failed"
+	case WarningDisconnectedOperation:
+		return "Disconnected Operation"
+	case WarningHeuristicExpiration:
+		return "Heuristic Expiration"
+	case WarningMiscellaneousWarning:
+		// TODO(pquerna): ideally had a better way to override this one code.
+		return "Miscellaneous Warning"
+	case WarningTransformationApplied:
+		return "Transformation Applied"
+	case WarningMiscellaneousPersistentWarning:
+		// TODO(pquerna): same as WarningMiscellaneousWarning
+		return "Miscellaneous Persistent Warning"
+	}
+
+	panic(w)
+}

src/vendor/github.com/pquerna/cachecontrol/doc.go

@@ -0,0 +1,25 @@
+/**
+ *  Copyright 2015 Paul Querna
+ *
+ *  Licensed under the Apache License, Version 2.0 (the "License");
+ *  you may not use this file except in compliance with the License.
+ *  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ *
+ */
+
+// Package cachecontrol implements the logic for HTTP Caching
+//
+// Deciding if an HTTP Response can be cached is often harder
+// and more bug prone than an actual cache storage backend.
+// cachecontrol provides a simple interface to determine if
+// request and response pairs are cachable as defined under
+// RFC 7234 http://tools.ietf.org/html/rfc7234
+package cachecontrol

src/vendor/golang.org/x/crypto/ed25519/ed25519.go

@@ -0,0 +1,181 @@
+// Copyright 2016 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Package ed25519 implements the Ed25519 signature algorithm. See
+// http://ed25519.cr.yp.to/.
+//
+// These functions are also compatible with the “Ed25519” function defined in
+// https://tools.ietf.org/html/draft-irtf-cfrg-eddsa-05.
+package ed25519
+
+// This code is a port of the public domain, “ref10” implementation of ed25519
+// from SUPERCOP.
+
+import (
+	"crypto"
+	cryptorand "crypto/rand"
+	"crypto/sha512"
+	"crypto/subtle"
+	"errors"
+	"io"
+	"strconv"
+
+	"golang.org/x/crypto/ed25519/internal/edwards25519"
+)
+
+const (
+	// PublicKeySize is the size, in bytes, of public keys as used in this package.
+	PublicKeySize = 32
+	// PrivateKeySize is the size, in bytes, of private keys as used in this package.
+	PrivateKeySize = 64
+	// SignatureSize is the size, in bytes, of signatures generated and verified by this package.
+	SignatureSize = 64
+)
+
+// PublicKey is the type of Ed25519 public keys.
+type PublicKey []byte
+
+// PrivateKey is the type of Ed25519 private keys. It implements crypto.Signer.
+type PrivateKey []byte
+
+// Public returns the PublicKey corresponding to priv.
+func (priv PrivateKey) Public() crypto.PublicKey {
+	publicKey := make([]byte, PublicKeySize)
+	copy(publicKey, priv[32:])
+	return PublicKey(publicKey)
+}
+
+// Sign signs the given message with priv.
+// Ed25519 performs two passes over messages to be signed and therefore cannot
+// handle pre-hashed messages. Thus opts.HashFunc() must return zero to
+// indicate the message hasn't been hashed. This can be achieved by passing
+// crypto.Hash(0) as the value for opts.
+func (priv PrivateKey) Sign(rand io.Reader, message []byte, opts crypto.SignerOpts) (signature []byte, err error) {
+	if opts.HashFunc() != crypto.Hash(0) {
+		return nil, errors.New("ed25519: cannot sign hashed message")
+	}
+
+	return Sign(priv, message), nil
+}
+
+// GenerateKey generates a public/private key pair using entropy from rand.
+// If rand is nil, crypto/rand.Reader will be used.
+func GenerateKey(rand io.Reader) (publicKey PublicKey, privateKey PrivateKey, err error) {
+	if rand == nil {
+		rand = cryptorand.Reader
+	}
+
+	privateKey = make([]byte, PrivateKeySize)
+	publicKey = make([]byte, PublicKeySize)
+	_, err = io.ReadFull(rand, privateKey[:32])
+	if err != nil {
+		return nil, nil, err
+	}
+
+	digest := sha512.Sum512(privateKey[:32])
+	digest[0] &= 248
+	digest[31] &= 127
+	digest[31] |= 64
+
+	var A edwards25519.ExtendedGroupElement
+	var hBytes [32]byte
+	copy(hBytes[:], digest[:])
+	edwards25519.GeScalarMultBase(&A, &hBytes)
+	var publicKeyBytes [32]byte
+	A.ToBytes(&publicKeyBytes)
+
+	copy(privateKey[32:], publicKeyBytes[:])
+	copy(publicKey, publicKeyBytes[:])
+
+	return publicKey, privateKey, nil
+}
+
+// Sign signs the message with privateKey and returns a signature. It will
+// panic if len(privateKey) is not PrivateKeySize.
+func Sign(privateKey PrivateKey, message []byte) []byte {
+	if l := len(privateKey); l != PrivateKeySize {
+		panic("ed25519: bad private key length: " + strconv.Itoa(l))
+	}
+
+	h := sha512.New()
+	h.Write(privateKey[:32])
+
+	var digest1, messageDigest, hramDigest [64]byte
+	var expandedSecretKey [32]byte
+	h.Sum(digest1[:0])
+	copy(expandedSecretKey[:], digest1[:])
+	expandedSecretKey[0] &= 248
+	expandedSecretKey[31] &= 63
+	expandedSecretKey[31] |= 64
+
+	h.Reset()
+	h.Write(digest1[32:])
+	h.Write(message)
+	h.Sum(messageDigest[:0])
+
+	var messageDigestReduced [32]byte
+	edwards25519.ScReduce(&messageDigestReduced, &messageDigest)
+	var R edwards25519.ExtendedGroupElement
+	edwards25519.GeScalarMultBase(&R, &messageDigestReduced)
+
+	var encodedR [32]byte
+	R.ToBytes(&encodedR)
+
+	h.Reset()
+	h.Write(encodedR[:])
+	h.Write(privateKey[32:])
+	h.Write(message)
+	h.Sum(hramDigest[:0])
+	var hramDigestReduced [32]byte
+	edwards25519.ScReduce(&hramDigestReduced, &hramDigest)
+
+	var s [32]byte
+	edwards25519.ScMulAdd(&s, &hramDigestReduced, &expandedSecretKey, &messageDigestReduced)
+
+	signature := make([]byte, SignatureSize)
+	copy(signature[:], encodedR[:])
+	copy(signature[32:], s[:])
+
+	return signature
+}
+
+// Verify reports whether sig is a valid signature of message by publicKey. It
+// will panic if len(publicKey) is not PublicKeySize.
+func Verify(publicKey PublicKey, message, sig []byte) bool {
+	if l := len(publicKey); l != PublicKeySize {
+		panic("ed25519: bad public key length: " + strconv.Itoa(l))
+	}
+
+	if len(sig) != SignatureSize || sig[63]&224 != 0 {
+		return false
+	}
+
+	var A edwards25519.ExtendedGroupElement
+	var publicKeyBytes [32]byte
+	copy(publicKeyBytes[:], publicKey)
+	if !A.FromBytes(&publicKeyBytes) {
+		return false
+	}
+	edwards25519.FeNeg(&A.X, &A.X)
+	edwards25519.FeNeg(&A.T, &A.T)
+
+	h := sha512.New()
+	h.Write(sig[:32])
+	h.Write(publicKey[:])
+	h.Write(message)
+	var digest [64]byte
+	h.Sum(digest[:0])
+
+	var hReduced [32]byte
+	edwards25519.ScReduce(&hReduced, &digest)
+
+	var R edwards25519.ProjectiveGroupElement
+	var b [32]byte
+	copy(b[:], sig[32:])
+	edwards25519.GeDoubleScalarMultVartime(&R, &hReduced, &A, &b)
+
+	var checkR [32]byte
+	R.ToBytes(&checkR)
+	return subtle.ConstantTimeCompare(sig[:32], checkR[:]) == 1
+}

src/vendor/gopkg.in/square/go-jose.v2/.gitcookies.sh.enc

@@ -0,0 +1 @@
+'|Ę&{tÄU|gGę(ěŹCy=+¨śňcű:u:/pś#~žü["±4¤!­nŮAŞDK<Šuf˙hĹażÂ:şü¸ˇ´B/ŁŘ¤ą¤ň_<C588>hÎŰSăT*wĚxĽŻťą-ç|ťŕŔÓ<C594>ŃÄäóĚ㣗A$$â6ŁÁâG)8nĎpűĆˡ3ĚšśoďĎvŽB–3ż­]xÝ“Ó2l§G•|qRŢŻ
ö2
5R–Ó×Ç$´ń˝YčˇŢÝ™l‘Ë«yAI"ŰŚ<C5B0>®íĂ»ąĽkÄ|Kĺţ[9ĆâŇĺ=°ú˙źń|@S•3ó#ćťx?ľV„,ľ‚SĆÝőśwPíogŇ6&V6	©D.dBŠ7

src/vendor/gopkg.in/square/go-jose.v2/.gitignore

@@ -0,0 +1,7 @@
+*~
+.*.swp
+*.out
+*.test
+*.pem
+*.cov
+jose-util/jose-util

src/vendor/gopkg.in/square/go-jose.v2/.travis.yml

@@ -0,0 +1,46 @@
+language: go
+
+sudo: false
+
+matrix:
+  fast_finish: true
+  allow_failures:
+    - go: tip
+
+go:
+- '1.7.x'
+- '1.8.x'
+- '1.9.x'
+- '1.10.x'
+- '1.11.x'
+
+go_import_path: gopkg.in/square/go-jose.v2
+
+before_script:
+- export PATH=$HOME/.local/bin:$PATH
+
+before_install:
+# Install encrypted gitcookies to get around bandwidth-limits
+# that is causing Travis-CI builds to fail. For more info, see
+# https://github.com/golang/go/issues/12933
+- openssl aes-256-cbc -K $encrypted_1528c3c2cafd_key -iv $encrypted_1528c3c2cafd_iv -in .gitcookies.sh.enc -out .gitcookies.sh -d || true
+- bash .gitcookies.sh || true
+- go get github.com/wadey/gocovmerge
+- go get github.com/mattn/goveralls
+- go get github.com/stretchr/testify/assert
+- go get golang.org/x/tools/cmd/cover || true
+- go get code.google.com/p/go.tools/cmd/cover || true
+- pip install cram --user
+
+script:
+- go test . -v -covermode=count -coverprofile=profile.cov
+- go test ./cipher -v -covermode=count -coverprofile=cipher/profile.cov
+- go test ./jwt -v -covermode=count -coverprofile=jwt/profile.cov
+- go test ./json -v # no coverage for forked encoding/json package
+- cd jose-util && go build && PATH=$PWD:$PATH cram -v jose-util.t
+- cd ..
+
+after_success:
+- gocovmerge *.cov */*.cov > merged.coverprofile
+- $HOME/gopath/bin/goveralls -coverprofile merged.coverprofile -service=travis-ci
+

src/vendor/gopkg.in/square/go-jose.v2/BUG-BOUNTY.md

@@ -0,0 +1,10 @@
+Serious about security
+======================
+
+Square recognizes the important contributions the security research community
+can make. We therefore encourage reporting security issues with the code
+contained in this repository.
+
+If you believe you have discovered a security vulnerability, please follow the
+guidelines at <https://bugcrowd.com/squareopensource>.
+

src/vendor/gopkg.in/square/go-jose.v2/CONTRIBUTING.md

@@ -0,0 +1,14 @@
+# Contributing
+
+If you would like to contribute code to go-jose you can do so through GitHub by
+forking the repository and sending a pull request.
+
+When submitting code, please make every effort to follow existing conventions
+and style in order to keep the code as readable as possible. Please also make
+sure all tests pass by running `go test`, and format your code with `go fmt`.
+We also recommend using `golint` and `errcheck`.
+
+Before your code can be accepted into the project you must also sign the
+[Individual Contributor License Agreement][1].
+
+ [1]: https://spreadsheets.google.com/spreadsheet/viewform?formkey=dDViT2xzUHAwRkI3X3k5Z0lQM091OGc6MQ&ndplr=1

src/vendor/gopkg.in/square/go-jose.v2/LICENSE

@@ -0,0 +1,202 @@
+
+                                 Apache License
+                           Version 2.0, January 2004
+                        http://www.apache.org/licenses/
+
+   TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION
+
+   1. Definitions.
+
+      "License" shall mean the terms and conditions for use, reproduction,
+      and distribution as defined by Sections 1 through 9 of this document.
+
+      "Licensor" shall mean the copyright owner or entity authorized by
+      the copyright owner that is granting the License.
+
+      "Legal Entity" shall mean the union of the acting entity and all
+      other entities that control, are controlled by, or are under common
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+      direction or management of such entity, whether by contract or
+      otherwise, or (ii) ownership of fifty percent (50%) or more of the
+      outstanding shares, or (iii) beneficial ownership of such entity.
+
+      "You" (or "Your") shall mean an individual or Legal Entity
+      exercising permissions granted by this License.
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+      "Source" form shall mean the preferred form for making modifications,
+      including but not limited to software source code, documentation
+      source, and configuration files.
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+      transformation or translation of a Source form, including but
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+      "Work" shall mean the work of authorship, whether in Source or
+      Object form, made available under the License, as indicated by a
+      copyright notice that is included in or attached to the work
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+      form, that is based on (or derived from) the Work and for which the
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+      represent, as a whole, an original work of authorship. For the purposes
+      of this License, Derivative Works shall not include works that remain
+      separable from, or merely link (or bind by name) to the interfaces of,
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+      the original version of the Work and any modifications or additions
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+      to the Licensor or its representatives, including but not limited to
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+      designated in writing by the copyright owner as "Not a Contribution."
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+      on behalf of whom a Contribution has been received by Licensor and
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+      the conditions stated in this License.
+
+   5. Submission of Contributions. Unless You explicitly state otherwise,
+      any Contribution intentionally submitted for inclusion in the Work
+      by You to the Licensor shall be under the terms and conditions of
+      this License, without any additional terms or conditions.
+      Notwithstanding the above, nothing herein shall supersede or modify
+      the terms of any separate license agreement you may have executed
+      with Licensor regarding such Contributions.
+
+   6. Trademarks. This License does not grant permission to use the trade
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+      Contributor provides its Contributions) on an "AS IS" BASIS,
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+      on Your own behalf and on Your sole responsibility, not on behalf
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+   You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.

src/vendor/gopkg.in/square/go-jose.v2/README.md

@@ -0,0 +1,118 @@
+# Go JOSE 
+
+[![godoc](http://img.shields.io/badge/godoc-version_1-blue.svg?style=flat)](https://godoc.org/gopkg.in/square/go-jose.v1)
+[![godoc](http://img.shields.io/badge/godoc-version_2-blue.svg?style=flat)](https://godoc.org/gopkg.in/square/go-jose.v2)
+[![license](http://img.shields.io/badge/license-apache_2.0-blue.svg?style=flat)](https://raw.githubusercontent.com/square/go-jose/master/LICENSE)
+[![build](https://travis-ci.org/square/go-jose.svg?branch=v2)](https://travis-ci.org/square/go-jose)
+[![coverage](https://coveralls.io/repos/github/square/go-jose/badge.svg?branch=v2)](https://coveralls.io/r/square/go-jose)
+
+Package jose aims to provide an implementation of the Javascript Object Signing
+and Encryption set of standards. This includes support for JSON Web Encryption,
+JSON Web Signature, and JSON Web Token standards.
+
+**Disclaimer**: This library contains encryption software that is subject to
+the U.S. Export Administration Regulations. You may not export, re-export,
+transfer or download this code or any part of it in violation of any United
+States law, directive or regulation. In particular this software may not be
+exported or re-exported in any form or on any media to Iran, North Sudan,
+Syria, Cuba, or North Korea, or to denied persons or entities mentioned on any
+US maintained blocked list.
+
+## Overview
+
+The implementation follows the
+[JSON Web Encryption](http://dx.doi.org/10.17487/RFC7516) (RFC 7516),
+[JSON Web Signature](http://dx.doi.org/10.17487/RFC7515) (RFC 7515), and
+[JSON Web Token](http://dx.doi.org/10.17487/RFC7519) (RFC 7519).
+Tables of supported algorithms are shown below. The library supports both
+the compact and full serialization formats, and has optional support for
+multiple recipients. It also comes with a small command-line utility
+([`jose-util`](https://github.com/square/go-jose/tree/v2/jose-util))
+for dealing with JOSE messages in a shell.
+
+**Note**: We use a forked version of the `encoding/json` package from the Go
+standard library which uses case-sensitive matching for member names (instead
+of [case-insensitive matching](https://www.ietf.org/mail-archive/web/json/current/msg03763.html)).
+This is to avoid differences in interpretation of messages between go-jose and
+libraries in other languages.
+
+### Versions
+
+We use [gopkg.in](https://gopkg.in) for versioning.
+
+[Version 2](https://gopkg.in/square/go-jose.v2)
+([branch](https://github.com/square/go-jose/tree/v2),
+[doc](https://godoc.org/gopkg.in/square/go-jose.v2)) is the current version:
+
+    import "gopkg.in/square/go-jose.v2"
+
+The old `v1` branch ([go-jose.v1](https://gopkg.in/square/go-jose.v1)) will
+still receive backported bug fixes and security fixes, but otherwise
+development is frozen. All new feature development takes place on the `v2`
+branch. Version 2 also contains additional sub-packages such as the
+[jwt](https://godoc.org/gopkg.in/square/go-jose.v2/jwt) implementation
+contributed by [@shaxbee](https://github.com/shaxbee).
+
+### Supported algorithms
+
+See below for a table of supported algorithms. Algorithm identifiers match
+the names in the [JSON Web Algorithms](http://dx.doi.org/10.17487/RFC7518)
+standard where possible. The Godoc reference has a list of constants.
+
+ Key encryption             | Algorithm identifier(s)
+ :------------------------- | :------------------------------
+ RSA-PKCS#1v1.5             | RSA1_5
+ RSA-OAEP                   | RSA-OAEP, RSA-OAEP-256
+ AES key wrap               | A128KW, A192KW, A256KW
+ AES-GCM key wrap           | A128GCMKW, A192GCMKW, A256GCMKW
+ ECDH-ES + AES key wrap     | ECDH-ES+A128KW, ECDH-ES+A192KW, ECDH-ES+A256KW
+ ECDH-ES (direct)           | ECDH-ES<sup>1</sup>
+ Direct encryption          | dir<sup>1</sup>
+
+<sup>1. Not supported in multi-recipient mode</sup>
+
+ Signing / MAC              | Algorithm identifier(s)
+ :------------------------- | :------------------------------
+ RSASSA-PKCS#1v1.5          | RS256, RS384, RS512
+ RSASSA-PSS                 | PS256, PS384, PS512
+ HMAC                       | HS256, HS384, HS512
+ ECDSA                      | ES256, ES384, ES512
+ Ed25519                    | EdDSA<sup>2</sup>
+
+<sup>2. Only available in version 2 of the package</sup>
+
+ Content encryption         | Algorithm identifier(s)
+ :------------------------- | :------------------------------
+ AES-CBC+HMAC               | A128CBC-HS256, A192CBC-HS384, A256CBC-HS512
+ AES-GCM                    | A128GCM, A192GCM, A256GCM 
+
+ Compression                | Algorithm identifiers(s)
+ :------------------------- | -------------------------------
+ DEFLATE (RFC 1951)         | DEF
+
+### Supported key types
+
+See below for a table of supported key types. These are understood by the
+library, and can be passed to corresponding functions such as `NewEncrypter` or
+`NewSigner`. Each of these keys can also be wrapped in a JWK if desired, which
+allows attaching a key id.
+
+ Algorithm(s)               | Corresponding types
+ :------------------------- | -------------------------------
+ RSA                        | *[rsa.PublicKey](http://golang.org/pkg/crypto/rsa/#PublicKey), *[rsa.PrivateKey](http://golang.org/pkg/crypto/rsa/#PrivateKey)
+ ECDH, ECDSA                | *[ecdsa.PublicKey](http://golang.org/pkg/crypto/ecdsa/#PublicKey), *[ecdsa.PrivateKey](http://golang.org/pkg/crypto/ecdsa/#PrivateKey)
+ EdDSA<sup>1</sup>          | [ed25519.PublicKey](https://godoc.org/golang.org/x/crypto/ed25519#PublicKey), [ed25519.PrivateKey](https://godoc.org/golang.org/x/crypto/ed25519#PrivateKey)
+ AES, HMAC                  | []byte
+
+<sup>1. Only available in version 2 of the package</sup>
+
+## Examples
+
+[![godoc](http://img.shields.io/badge/godoc-version_1-blue.svg?style=flat)](https://godoc.org/gopkg.in/square/go-jose.v1)
+[![godoc](http://img.shields.io/badge/godoc-version_2-blue.svg?style=flat)](https://godoc.org/gopkg.in/square/go-jose.v2)
+
+Examples can be found in the Godoc
+reference for this package. The
+[`jose-util`](https://github.com/square/go-jose/tree/v2/jose-util)
+subdirectory also contains a small command-line utility which might be useful
+as an example.

src/vendor/gopkg.in/square/go-jose.v2/asymmetric.go

@@ -0,0 +1,592 @@
+/*-
+ * Copyright 2014 Square Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package jose
+
+import (
+	"crypto"
+	"crypto/aes"
+	"crypto/ecdsa"
+	"crypto/rand"
+	"crypto/rsa"
+	"crypto/sha1"
+	"crypto/sha256"
+	"errors"
+	"fmt"
+	"math/big"
+
+	"golang.org/x/crypto/ed25519"
+	"gopkg.in/square/go-jose.v2/cipher"
+	"gopkg.in/square/go-jose.v2/json"
+)
+
+// A generic RSA-based encrypter/verifier
+type rsaEncrypterVerifier struct {
+	publicKey *rsa.PublicKey
+}
+
+// A generic RSA-based decrypter/signer
+type rsaDecrypterSigner struct {
+	privateKey *rsa.PrivateKey
+}
+
+// A generic EC-based encrypter/verifier
+type ecEncrypterVerifier struct {
+	publicKey *ecdsa.PublicKey
+}
+
+type edEncrypterVerifier struct {
+	publicKey ed25519.PublicKey
+}
+
+// A key generator for ECDH-ES
+type ecKeyGenerator struct {
+	size      int
+	algID     string
+	publicKey *ecdsa.PublicKey
+}
+
+// A generic EC-based decrypter/signer
+type ecDecrypterSigner struct {
+	privateKey *ecdsa.PrivateKey
+}
+
+type edDecrypterSigner struct {
+	privateKey ed25519.PrivateKey
+}
+
+// newRSARecipient creates recipientKeyInfo based on the given key.
+func newRSARecipient(keyAlg KeyAlgorithm, publicKey *rsa.PublicKey) (recipientKeyInfo, error) {
+	// Verify that key management algorithm is supported by this encrypter
+	switch keyAlg {
+	case RSA1_5, RSA_OAEP, RSA_OAEP_256:
+	default:
+		return recipientKeyInfo{}, ErrUnsupportedAlgorithm
+	}
+
+	if publicKey == nil {
+		return recipientKeyInfo{}, errors.New("invalid public key")
+	}
+
+	return recipientKeyInfo{
+		keyAlg: keyAlg,
+		keyEncrypter: &rsaEncrypterVerifier{
+			publicKey: publicKey,
+		},
+	}, nil
+}
+
+// newRSASigner creates a recipientSigInfo based on the given key.
+func newRSASigner(sigAlg SignatureAlgorithm, privateKey *rsa.PrivateKey) (recipientSigInfo, error) {
+	// Verify that key management algorithm is supported by this encrypter
+	switch sigAlg {
+	case RS256, RS384, RS512, PS256, PS384, PS512:
+	default:
+		return recipientSigInfo{}, ErrUnsupportedAlgorithm
+	}
+
+	if privateKey == nil {
+		return recipientSigInfo{}, errors.New("invalid private key")
+	}
+
+	return recipientSigInfo{
+		sigAlg: sigAlg,
+		publicKey: staticPublicKey(&JSONWebKey{
+			Key: privateKey.Public(),
+		}),
+		signer: &rsaDecrypterSigner{
+			privateKey: privateKey,
+		},
+	}, nil
+}
+
+func newEd25519Signer(sigAlg SignatureAlgorithm, privateKey ed25519.PrivateKey) (recipientSigInfo, error) {
+	if sigAlg != EdDSA {
+		return recipientSigInfo{}, ErrUnsupportedAlgorithm
+	}
+
+	if privateKey == nil {
+		return recipientSigInfo{}, errors.New("invalid private key")
+	}
+	return recipientSigInfo{
+		sigAlg: sigAlg,
+		publicKey: staticPublicKey(&JSONWebKey{
+			Key: privateKey.Public(),
+		}),
+		signer: &edDecrypterSigner{
+			privateKey: privateKey,
+		},
+	}, nil
+}
+
+// newECDHRecipient creates recipientKeyInfo based on the given key.
+func newECDHRecipient(keyAlg KeyAlgorithm, publicKey *ecdsa.PublicKey) (recipientKeyInfo, error) {
+	// Verify that key management algorithm is supported by this encrypter
+	switch keyAlg {
+	case ECDH_ES, ECDH_ES_A128KW, ECDH_ES_A192KW, ECDH_ES_A256KW:
+	default:
+		return recipientKeyInfo{}, ErrUnsupportedAlgorithm
+	}
+
+	if publicKey == nil || !publicKey.Curve.IsOnCurve(publicKey.X, publicKey.Y) {
+		return recipientKeyInfo{}, errors.New("invalid public key")
+	}
+
+	return recipientKeyInfo{
+		keyAlg: keyAlg,
+		keyEncrypter: &ecEncrypterVerifier{
+			publicKey: publicKey,
+		},
+	}, nil
+}
+
+// newECDSASigner creates a recipientSigInfo based on the given key.
+func newECDSASigner(sigAlg SignatureAlgorithm, privateKey *ecdsa.PrivateKey) (recipientSigInfo, error) {
+	// Verify that key management algorithm is supported by this encrypter
+	switch sigAlg {
+	case ES256, ES384, ES512:
+	default:
+		return recipientSigInfo{}, ErrUnsupportedAlgorithm
+	}
+
+	if privateKey == nil {
+		return recipientSigInfo{}, errors.New("invalid private key")
+	}
+
+	return recipientSigInfo{
+		sigAlg: sigAlg,
+		publicKey: staticPublicKey(&JSONWebKey{
+			Key: privateKey.Public(),
+		}),
+		signer: &ecDecrypterSigner{
+			privateKey: privateKey,
+		},
+	}, nil
+}
+
+// Encrypt the given payload and update the object.
+func (ctx rsaEncrypterVerifier) encryptKey(cek []byte, alg KeyAlgorithm) (recipientInfo, error) {
+	encryptedKey, err := ctx.encrypt(cek, alg)
+	if err != nil {
+		return recipientInfo{}, err
+	}
+
+	return recipientInfo{
+		encryptedKey: encryptedKey,
+		header:       &rawHeader{},
+	}, nil
+}
+
+// Encrypt the given payload. Based on the key encryption algorithm,
+// this will either use RSA-PKCS1v1.5 or RSA-OAEP (with SHA-1 or SHA-256).
+func (ctx rsaEncrypterVerifier) encrypt(cek []byte, alg KeyAlgorithm) ([]byte, error) {
+	switch alg {
+	case RSA1_5:
+		return rsa.EncryptPKCS1v15(RandReader, ctx.publicKey, cek)
+	case RSA_OAEP:
+		return rsa.EncryptOAEP(sha1.New(), RandReader, ctx.publicKey, cek, []byte{})
+	case RSA_OAEP_256:
+		return rsa.EncryptOAEP(sha256.New(), RandReader, ctx.publicKey, cek, []byte{})
+	}
+
+	return nil, ErrUnsupportedAlgorithm
+}
+
+// Decrypt the given payload and return the content encryption key.
+func (ctx rsaDecrypterSigner) decryptKey(headers rawHeader, recipient *recipientInfo, generator keyGenerator) ([]byte, error) {
+	return ctx.decrypt(recipient.encryptedKey, headers.getAlgorithm(), generator)
+}
+
+// Decrypt the given payload. Based on the key encryption algorithm,
+// this will either use RSA-PKCS1v1.5 or RSA-OAEP (with SHA-1 or SHA-256).
+func (ctx rsaDecrypterSigner) decrypt(jek []byte, alg KeyAlgorithm, generator keyGenerator) ([]byte, error) {
+	// Note: The random reader on decrypt operations is only used for blinding,
+	// so stubbing is meanlingless (hence the direct use of rand.Reader).
+	switch alg {
+	case RSA1_5:
+		defer func() {
+			// DecryptPKCS1v15SessionKey sometimes panics on an invalid payload
+			// because of an index out of bounds error, which we want to ignore.
+			// This has been fixed in Go 1.3.1 (released 2014/08/13), the recover()
+			// only exists for preventing crashes with unpatched versions.
+			// See: https://groups.google.com/forum/#!topic/golang-dev/7ihX6Y6kx9k
+			// See: https://code.google.com/p/go/source/detail?r=58ee390ff31602edb66af41ed10901ec95904d33
+			_ = recover()
+		}()
+
+		// Perform some input validation.
+		keyBytes := ctx.privateKey.PublicKey.N.BitLen() / 8
+		if keyBytes != len(jek) {
+			// Input size is incorrect, the encrypted payload should always match
+			// the size of the public modulus (e.g. using a 2048 bit key will
+			// produce 256 bytes of output). Reject this since it's invalid input.
+			return nil, ErrCryptoFailure
+		}
+
+		cek, _, err := generator.genKey()
+		if err != nil {
+			return nil, ErrCryptoFailure
+		}
+
+		// When decrypting an RSA-PKCS1v1.5 payload, we must take precautions to
+		// prevent chosen-ciphertext attacks as described in RFC 3218, "Preventing
+		// the Million Message Attack on Cryptographic Message Syntax". We are
+		// therefore deliberately ignoring errors here.
+		_ = rsa.DecryptPKCS1v15SessionKey(rand.Reader, ctx.privateKey, jek, cek)
+
+		return cek, nil
+	case RSA_OAEP:
+		// Use rand.Reader for RSA blinding
+		return rsa.DecryptOAEP(sha1.New(), rand.Reader, ctx.privateKey, jek, []byte{})
+	case RSA_OAEP_256:
+		// Use rand.Reader for RSA blinding
+		return rsa.DecryptOAEP(sha256.New(), rand.Reader, ctx.privateKey, jek, []byte{})
+	}
+
+	return nil, ErrUnsupportedAlgorithm
+}
+
+// Sign the given payload
+func (ctx rsaDecrypterSigner) signPayload(payload []byte, alg SignatureAlgorithm) (Signature, error) {
+	var hash crypto.Hash
+
+	switch alg {
+	case RS256, PS256:
+		hash = crypto.SHA256
+	case RS384, PS384:
+		hash = crypto.SHA384
+	case RS512, PS512:
+		hash = crypto.SHA512
+	default:
+		return Signature{}, ErrUnsupportedAlgorithm
+	}
+
+	hasher := hash.New()
+
+	// According to documentation, Write() on hash never fails
+	_, _ = hasher.Write(payload)
+	hashed := hasher.Sum(nil)
+
+	var out []byte
+	var err error
+
+	switch alg {
+	case RS256, RS384, RS512:
+		out, err = rsa.SignPKCS1v15(RandReader, ctx.privateKey, hash, hashed)
+	case PS256, PS384, PS512:
+		out, err = rsa.SignPSS(RandReader, ctx.privateKey, hash, hashed, &rsa.PSSOptions{
+			SaltLength: rsa.PSSSaltLengthAuto,
+		})
+	}
+
+	if err != nil {
+		return Signature{}, err
+	}
+
+	return Signature{
+		Signature: out,
+		protected: &rawHeader{},
+	}, nil
+}
+
+// Verify the given payload
+func (ctx rsaEncrypterVerifier) verifyPayload(payload []byte, signature []byte, alg SignatureAlgorithm) error {
+	var hash crypto.Hash
+
+	switch alg {
+	case RS256, PS256:
+		hash = crypto.SHA256
+	case RS384, PS384:
+		hash = crypto.SHA384
+	case RS512, PS512:
+		hash = crypto.SHA512
+	default:
+		return ErrUnsupportedAlgorithm
+	}
+
+	hasher := hash.New()
+
+	// According to documentation, Write() on hash never fails
+	_, _ = hasher.Write(payload)
+	hashed := hasher.Sum(nil)
+
+	switch alg {
+	case RS256, RS384, RS512:
+		return rsa.VerifyPKCS1v15(ctx.publicKey, hash, hashed, signature)
+	case PS256, PS384, PS512:
+		return rsa.VerifyPSS(ctx.publicKey, hash, hashed, signature, nil)
+	}
+
+	return ErrUnsupportedAlgorithm
+}
+
+// Encrypt the given payload and update the object.
+func (ctx ecEncrypterVerifier) encryptKey(cek []byte, alg KeyAlgorithm) (recipientInfo, error) {
+	switch alg {
+	case ECDH_ES:
+		// ECDH-ES mode doesn't wrap a key, the shared secret is used directly as the key.
+		return recipientInfo{
+			header: &rawHeader{},
+		}, nil
+	case ECDH_ES_A128KW, ECDH_ES_A192KW, ECDH_ES_A256KW:
+	default:
+		return recipientInfo{}, ErrUnsupportedAlgorithm
+	}
+
+	generator := ecKeyGenerator{
+		algID:     string(alg),
+		publicKey: ctx.publicKey,
+	}
+
+	switch alg {
+	case ECDH_ES_A128KW:
+		generator.size = 16
+	case ECDH_ES_A192KW:
+		generator.size = 24
+	case ECDH_ES_A256KW:
+		generator.size = 32
+	}
+
+	kek, header, err := generator.genKey()
+	if err != nil {
+		return recipientInfo{}, err
+	}
+
+	block, err := aes.NewCipher(kek)
+	if err != nil {
+		return recipientInfo{}, err
+	}
+
+	jek, err := josecipher.KeyWrap(block, cek)
+	if err != nil {
+		return recipientInfo{}, err
+	}
+
+	return recipientInfo{
+		encryptedKey: jek,
+		header:       &header,
+	}, nil
+}
+
+// Get key size for EC key generator
+func (ctx ecKeyGenerator) keySize() int {
+	return ctx.size
+}
+
+// Get a content encryption key for ECDH-ES
+func (ctx ecKeyGenerator) genKey() ([]byte, rawHeader, error) {
+	priv, err := ecdsa.GenerateKey(ctx.publicKey.Curve, RandReader)
+	if err != nil {
+		return nil, rawHeader{}, err
+	}
+
+	out := josecipher.DeriveECDHES(ctx.algID, []byte{}, []byte{}, priv, ctx.publicKey, ctx.size)
+
+	b, err := json.Marshal(&JSONWebKey{
+		Key: &priv.PublicKey,
+	})
+	if err != nil {
+		return nil, nil, err
+	}
+
+	headers := rawHeader{
+		headerEPK: makeRawMessage(b),
+	}
+
+	return out, headers, nil
+}
+
+// Decrypt the given payload and return the content encryption key.
+func (ctx ecDecrypterSigner) decryptKey(headers rawHeader, recipient *recipientInfo, generator keyGenerator) ([]byte, error) {
+	epk, err := headers.getEPK()
+	if err != nil {
+		return nil, errors.New("square/go-jose: invalid epk header")
+	}
+	if epk == nil {
+		return nil, errors.New("square/go-jose: missing epk header")
+	}
+
+	publicKey, ok := epk.Key.(*ecdsa.PublicKey)
+	if publicKey == nil || !ok {
+		return nil, errors.New("square/go-jose: invalid epk header")
+	}
+
+	if !ctx.privateKey.Curve.IsOnCurve(publicKey.X, publicKey.Y) {
+		return nil, errors.New("square/go-jose: invalid public key in epk header")
+	}
+
+	apuData, err := headers.getAPU()
+	if err != nil {
+		return nil, errors.New("square/go-jose: invalid apu header")
+	}
+	apvData, err := headers.getAPV()
+	if err != nil {
+		return nil, errors.New("square/go-jose: invalid apv header")
+	}
+
+	deriveKey := func(algID string, size int) []byte {
+		return josecipher.DeriveECDHES(algID, apuData.bytes(), apvData.bytes(), ctx.privateKey, publicKey, size)
+	}
+
+	var keySize int
+
+	algorithm := headers.getAlgorithm()
+	switch algorithm {
+	case ECDH_ES:
+		// ECDH-ES uses direct key agreement, no key unwrapping necessary.
+		return deriveKey(string(headers.getEncryption()), generator.keySize()), nil
+	case ECDH_ES_A128KW:
+		keySize = 16
+	case ECDH_ES_A192KW:
+		keySize = 24
+	case ECDH_ES_A256KW:
+		keySize = 32
+	default:
+		return nil, ErrUnsupportedAlgorithm
+	}
+
+	key := deriveKey(string(algorithm), keySize)
+	block, err := aes.NewCipher(key)
+	if err != nil {
+		return nil, err
+	}
+
+	return josecipher.KeyUnwrap(block, recipient.encryptedKey)
+}
+
+func (ctx edDecrypterSigner) signPayload(payload []byte, alg SignatureAlgorithm) (Signature, error) {
+	if alg != EdDSA {
+		return Signature{}, ErrUnsupportedAlgorithm
+	}
+
+	sig, err := ctx.privateKey.Sign(RandReader, payload, crypto.Hash(0))
+	if err != nil {
+		return Signature{}, err
+	}
+
+	return Signature{
+		Signature: sig,
+		protected: &rawHeader{},
+	}, nil
+}
+
+func (ctx edEncrypterVerifier) verifyPayload(payload []byte, signature []byte, alg SignatureAlgorithm) error {
+	if alg != EdDSA {
+		return ErrUnsupportedAlgorithm
+	}
+	ok := ed25519.Verify(ctx.publicKey, payload, signature)
+	if !ok {
+		return errors.New("square/go-jose: ed25519 signature failed to verify")
+	}
+	return nil
+}
+
+// Sign the given payload
+func (ctx ecDecrypterSigner) signPayload(payload []byte, alg SignatureAlgorithm) (Signature, error) {
+	var expectedBitSize int
+	var hash crypto.Hash
+
+	switch alg {
+	case ES256:
+		expectedBitSize = 256
+		hash = crypto.SHA256
+	case ES384:
+		expectedBitSize = 384
+		hash = crypto.SHA384
+	case ES512:
+		expectedBitSize = 521
+		hash = crypto.SHA512
+	}
+
+	curveBits := ctx.privateKey.Curve.Params().BitSize
+	if expectedBitSize != curveBits {
+		return Signature{}, fmt.Errorf("square/go-jose: expected %d bit key, got %d bits instead", expectedBitSize, curveBits)
+	}
+
+	hasher := hash.New()
+
+	// According to documentation, Write() on hash never fails
+	_, _ = hasher.Write(payload)
+	hashed := hasher.Sum(nil)
+
+	r, s, err := ecdsa.Sign(RandReader, ctx.privateKey, hashed)
+	if err != nil {
+		return Signature{}, err
+	}
+
+	keyBytes := curveBits / 8
+	if curveBits%8 > 0 {
+		keyBytes++
+	}
+
+	// We serialize the outputs (r and s) into big-endian byte arrays and pad
+	// them with zeros on the left to make sure the sizes work out. Both arrays
+	// must be keyBytes long, and the output must be 2*keyBytes long.
+	rBytes := r.Bytes()
+	rBytesPadded := make([]byte, keyBytes)
+	copy(rBytesPadded[keyBytes-len(rBytes):], rBytes)
+
+	sBytes := s.Bytes()
+	sBytesPadded := make([]byte, keyBytes)
+	copy(sBytesPadded[keyBytes-len(sBytes):], sBytes)
+
+	out := append(rBytesPadded, sBytesPadded...)
+
+	return Signature{
+		Signature: out,
+		protected: &rawHeader{},
+	}, nil
+}
+
+// Verify the given payload
+func (ctx ecEncrypterVerifier) verifyPayload(payload []byte, signature []byte, alg SignatureAlgorithm) error {
+	var keySize int
+	var hash crypto.Hash
+
+	switch alg {
+	case ES256:
+		keySize = 32
+		hash = crypto.SHA256
+	case ES384:
+		keySize = 48
+		hash = crypto.SHA384
+	case ES512:
+		keySize = 66
+		hash = crypto.SHA512
+	default:
+		return ErrUnsupportedAlgorithm
+	}
+
+	if len(signature) != 2*keySize {
+		return fmt.Errorf("square/go-jose: invalid signature size, have %d bytes, wanted %d", len(signature), 2*keySize)
+	}
+
+	hasher := hash.New()
+
+	// According to documentation, Write() on hash never fails
+	_, _ = hasher.Write(payload)
+	hashed := hasher.Sum(nil)
+
+	r := big.NewInt(0).SetBytes(signature[:keySize])
+	s := big.NewInt(0).SetBytes(signature[keySize:])
+
+	match := ecdsa.Verify(ctx.publicKey, hashed, r, s)
+	if !match {
+		return errors.New("square/go-jose: ecdsa signature failed to verify")
+	}
+
+	return nil
+}

src/vendor/gopkg.in/square/go-jose.v2/cipher/cbc_hmac.go

@@ -0,0 +1,196 @@
+/*-
+ * Copyright 2014 Square Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package josecipher
+
+import (
+	"bytes"
+	"crypto/cipher"
+	"crypto/hmac"
+	"crypto/sha256"
+	"crypto/sha512"
+	"crypto/subtle"
+	"encoding/binary"
+	"errors"
+	"hash"
+)
+
+const (
+	nonceBytes = 16
+)
+
+// NewCBCHMAC instantiates a new AEAD based on CBC+HMAC.
+func NewCBCHMAC(key []byte, newBlockCipher func([]byte) (cipher.Block, error)) (cipher.AEAD, error) {
+	keySize := len(key) / 2
+	integrityKey := key[:keySize]
+	encryptionKey := key[keySize:]
+
+	blockCipher, err := newBlockCipher(encryptionKey)
+	if err != nil {
+		return nil, err
+	}
+
+	var hash func() hash.Hash
+	switch keySize {
+	case 16:
+		hash = sha256.New
+	case 24:
+		hash = sha512.New384
+	case 32:
+		hash = sha512.New
+	}
+
+	return &cbcAEAD{
+		hash:         hash,
+		blockCipher:  blockCipher,
+		authtagBytes: keySize,
+		integrityKey: integrityKey,
+	}, nil
+}
+
+// An AEAD based on CBC+HMAC
+type cbcAEAD struct {
+	hash         func() hash.Hash
+	authtagBytes int
+	integrityKey []byte
+	blockCipher  cipher.Block
+}
+
+func (ctx *cbcAEAD) NonceSize() int {
+	return nonceBytes
+}
+
+func (ctx *cbcAEAD) Overhead() int {
+	// Maximum overhead is block size (for padding) plus auth tag length, where
+	// the length of the auth tag is equivalent to the key size.
+	return ctx.blockCipher.BlockSize() + ctx.authtagBytes
+}
+
+// Seal encrypts and authenticates the plaintext.
+func (ctx *cbcAEAD) Seal(dst, nonce, plaintext, data []byte) []byte {
+	// Output buffer -- must take care not to mangle plaintext input.
+	ciphertext := make([]byte, uint64(len(plaintext))+uint64(ctx.Overhead()))[:len(plaintext)]
+	copy(ciphertext, plaintext)
+	ciphertext = padBuffer(ciphertext, ctx.blockCipher.BlockSize())
+
+	cbc := cipher.NewCBCEncrypter(ctx.blockCipher, nonce)
+
+	cbc.CryptBlocks(ciphertext, ciphertext)
+	authtag := ctx.computeAuthTag(data, nonce, ciphertext)
+
+	ret, out := resize(dst, uint64(len(dst))+uint64(len(ciphertext))+uint64(len(authtag)))
+	copy(out, ciphertext)
+	copy(out[len(ciphertext):], authtag)
+
+	return ret
+}
+
+// Open decrypts and authenticates the ciphertext.
+func (ctx *cbcAEAD) Open(dst, nonce, ciphertext, data []byte) ([]byte, error) {
+	if len(ciphertext) < ctx.authtagBytes {
+		return nil, errors.New("square/go-jose: invalid ciphertext (too short)")
+	}
+
+	offset := len(ciphertext) - ctx.authtagBytes
+	expectedTag := ctx.computeAuthTag(data, nonce, ciphertext[:offset])
+	match := subtle.ConstantTimeCompare(expectedTag, ciphertext[offset:])
+	if match != 1 {
+		return nil, errors.New("square/go-jose: invalid ciphertext (auth tag mismatch)")
+	}
+
+	cbc := cipher.NewCBCDecrypter(ctx.blockCipher, nonce)
+
+	// Make copy of ciphertext buffer, don't want to modify in place
+	buffer := append([]byte{}, []byte(ciphertext[:offset])...)
+
+	if len(buffer)%ctx.blockCipher.BlockSize() > 0 {
+		return nil, errors.New("square/go-jose: invalid ciphertext (invalid length)")
+	}
+
+	cbc.CryptBlocks(buffer, buffer)
+
+	// Remove padding
+	plaintext, err := unpadBuffer(buffer, ctx.blockCipher.BlockSize())
+	if err != nil {
+		return nil, err
+	}
+
+	ret, out := resize(dst, uint64(len(dst))+uint64(len(plaintext)))
+	copy(out, plaintext)
+
+	return ret, nil
+}
+
+// Compute an authentication tag
+func (ctx *cbcAEAD) computeAuthTag(aad, nonce, ciphertext []byte) []byte {
+	buffer := make([]byte, uint64(len(aad))+uint64(len(nonce))+uint64(len(ciphertext))+8)
+	n := 0
+	n += copy(buffer, aad)
+	n += copy(buffer[n:], nonce)
+	n += copy(buffer[n:], ciphertext)
+	binary.BigEndian.PutUint64(buffer[n:], uint64(len(aad))*8)
+
+	// According to documentation, Write() on hash.Hash never fails.
+	hmac := hmac.New(ctx.hash, ctx.integrityKey)
+	_, _ = hmac.Write(buffer)
+
+	return hmac.Sum(nil)[:ctx.authtagBytes]
+}
+
+// resize ensures the the given slice has a capacity of at least n bytes.
+// If the capacity of the slice is less than n, a new slice is allocated
+// and the existing data will be copied.
+func resize(in []byte, n uint64) (head, tail []byte) {
+	if uint64(cap(in)) >= n {
+		head = in[:n]
+	} else {
+		head = make([]byte, n)
+		copy(head, in)
+	}
+
+	tail = head[len(in):]
+	return
+}
+
+// Apply padding
+func padBuffer(buffer []byte, blockSize int) []byte {
+	missing := blockSize - (len(buffer) % blockSize)
+	ret, out := resize(buffer, uint64(len(buffer))+uint64(missing))
+	padding := bytes.Repeat([]byte{byte(missing)}, missing)
+	copy(out, padding)
+	return ret
+}
+
+// Remove padding
+func unpadBuffer(buffer []byte, blockSize int) ([]byte, error) {
+	if len(buffer)%blockSize != 0 {
+		return nil, errors.New("square/go-jose: invalid padding")
+	}
+
+	last := buffer[len(buffer)-1]
+	count := int(last)
+
+	if count == 0 || count > blockSize || count > len(buffer) {
+		return nil, errors.New("square/go-jose: invalid padding")
+	}
+
+	padding := bytes.Repeat([]byte{last}, count)
+	if !bytes.HasSuffix(buffer, padding) {
+		return nil, errors.New("square/go-jose: invalid padding")
+	}
+
+	return buffer[:len(buffer)-count], nil
+}

src/vendor/gopkg.in/square/go-jose.v2/cipher/concat_kdf.go

@@ -0,0 +1,75 @@
+/*-
+ * Copyright 2014 Square Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package josecipher
+
+import (
+	"crypto"
+	"encoding/binary"
+	"hash"
+	"io"
+)
+
+type concatKDF struct {
+	z, info []byte
+	i       uint32
+	cache   []byte
+	hasher  hash.Hash
+}
+
+// NewConcatKDF builds a KDF reader based on the given inputs.
+func NewConcatKDF(hash crypto.Hash, z, algID, ptyUInfo, ptyVInfo, supPubInfo, supPrivInfo []byte) io.Reader {
+	buffer := make([]byte, uint64(len(algID))+uint64(len(ptyUInfo))+uint64(len(ptyVInfo))+uint64(len(supPubInfo))+uint64(len(supPrivInfo)))
+	n := 0
+	n += copy(buffer, algID)
+	n += copy(buffer[n:], ptyUInfo)
+	n += copy(buffer[n:], ptyVInfo)
+	n += copy(buffer[n:], supPubInfo)
+	copy(buffer[n:], supPrivInfo)
+
+	hasher := hash.New()
+
+	return &concatKDF{
+		z:      z,
+		info:   buffer,
+		hasher: hasher,
+		cache:  []byte{},
+		i:      1,
+	}
+}
+
+func (ctx *concatKDF) Read(out []byte) (int, error) {
+	copied := copy(out, ctx.cache)
+	ctx.cache = ctx.cache[copied:]
+
+	for copied < len(out) {
+		ctx.hasher.Reset()
+
+		// Write on a hash.Hash never fails
+		_ = binary.Write(ctx.hasher, binary.BigEndian, ctx.i)
+		_, _ = ctx.hasher.Write(ctx.z)
+		_, _ = ctx.hasher.Write(ctx.info)
+
+		hash := ctx.hasher.Sum(nil)
+		chunkCopied := copy(out[copied:], hash)
+		copied += chunkCopied
+		ctx.cache = hash[chunkCopied:]
+
+		ctx.i++
+	}
+
+	return copied, nil
+}

src/vendor/gopkg.in/square/go-jose.v2/cipher/ecdh_es.go

@@ -0,0 +1,62 @@
+/*-
+ * Copyright 2014 Square Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package josecipher
+
+import (
+	"crypto"
+	"crypto/ecdsa"
+	"encoding/binary"
+)
+
+// DeriveECDHES derives a shared encryption key using ECDH/ConcatKDF as described in JWE/JWA.
+// It is an error to call this function with a private/public key that are not on the same
+// curve. Callers must ensure that the keys are valid before calling this function. Output
+// size may be at most 1<<16 bytes (64 KiB).
+func DeriveECDHES(alg string, apuData, apvData []byte, priv *ecdsa.PrivateKey, pub *ecdsa.PublicKey, size int) []byte {
+	if size > 1<<16 {
+		panic("ECDH-ES output size too large, must be less than or equal to 1<<16")
+	}
+
+	// algId, partyUInfo, partyVInfo inputs must be prefixed with the length
+	algID := lengthPrefixed([]byte(alg))
+	ptyUInfo := lengthPrefixed(apuData)
+	ptyVInfo := lengthPrefixed(apvData)
+
+	// suppPubInfo is the encoded length of the output size in bits
+	supPubInfo := make([]byte, 4)
+	binary.BigEndian.PutUint32(supPubInfo, uint32(size)*8)
+
+	if !priv.PublicKey.Curve.IsOnCurve(pub.X, pub.Y) {
+		panic("public key not on same curve as private key")
+	}
+
+	z, _ := priv.PublicKey.Curve.ScalarMult(pub.X, pub.Y, priv.D.Bytes())
+	reader := NewConcatKDF(crypto.SHA256, z.Bytes(), algID, ptyUInfo, ptyVInfo, supPubInfo, []byte{})
+
+	key := make([]byte, size)
+
+	// Read on the KDF will never fail
+	_, _ = reader.Read(key)
+	return key
+}
+
+func lengthPrefixed(data []byte) []byte {
+	out := make([]byte, len(data)+4)
+	binary.BigEndian.PutUint32(out, uint32(len(data)))
+	copy(out[4:], data)
+	return out
+}

src/vendor/gopkg.in/square/go-jose.v2/cipher/key_wrap.go

@@ -0,0 +1,109 @@
+/*-
+ * Copyright 2014 Square Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package josecipher
+
+import (
+	"crypto/cipher"
+	"crypto/subtle"
+	"encoding/binary"
+	"errors"
+)
+
+var defaultIV = []byte{0xA6, 0xA6, 0xA6, 0xA6, 0xA6, 0xA6, 0xA6, 0xA6}
+
+// KeyWrap implements NIST key wrapping; it wraps a content encryption key (cek) with the given block cipher.
+func KeyWrap(block cipher.Block, cek []byte) ([]byte, error) {
+	if len(cek)%8 != 0 {
+		return nil, errors.New("square/go-jose: key wrap input must be 8 byte blocks")
+	}
+
+	n := len(cek) / 8
+	r := make([][]byte, n)
+
+	for i := range r {
+		r[i] = make([]byte, 8)
+		copy(r[i], cek[i*8:])
+	}
+
+	buffer := make([]byte, 16)
+	tBytes := make([]byte, 8)
+	copy(buffer, defaultIV)
+
+	for t := 0; t < 6*n; t++ {
+		copy(buffer[8:], r[t%n])
+
+		block.Encrypt(buffer, buffer)
+
+		binary.BigEndian.PutUint64(tBytes, uint64(t+1))
+
+		for i := 0; i < 8; i++ {
+			buffer[i] = buffer[i] ^ tBytes[i]
+		}
+		copy(r[t%n], buffer[8:])
+	}
+
+	out := make([]byte, (n+1)*8)
+	copy(out, buffer[:8])
+	for i := range r {
+		copy(out[(i+1)*8:], r[i])
+	}
+
+	return out, nil
+}
+
+// KeyUnwrap implements NIST key unwrapping; it unwraps a content encryption key (cek) with the given block cipher.
+func KeyUnwrap(block cipher.Block, ciphertext []byte) ([]byte, error) {
+	if len(ciphertext)%8 != 0 {
+		return nil, errors.New("square/go-jose: key wrap input must be 8 byte blocks")
+	}
+
+	n := (len(ciphertext) / 8) - 1
+	r := make([][]byte, n)
+
+	for i := range r {
+		r[i] = make([]byte, 8)
+		copy(r[i], ciphertext[(i+1)*8:])
+	}
+
+	buffer := make([]byte, 16)
+	tBytes := make([]byte, 8)
+	copy(buffer[:8], ciphertext[:8])
+
+	for t := 6*n - 1; t >= 0; t-- {
+		binary.BigEndian.PutUint64(tBytes, uint64(t+1))
+
+		for i := 0; i < 8; i++ {
+			buffer[i] = buffer[i] ^ tBytes[i]
+		}
+		copy(buffer[8:], r[t%n])
+
+		block.Decrypt(buffer, buffer)
+
+		copy(r[t%n], buffer[8:])
+	}
+
+	if subtle.ConstantTimeCompare(buffer[:8], defaultIV) == 0 {
+		return nil, errors.New("square/go-jose: failed to unwrap key")
+	}
+
+	out := make([]byte, n*8)
+	for i := range r {
+		copy(out[i*8:], r[i])
+	}
+
+	return out, nil
+}

src/vendor/gopkg.in/square/go-jose.v2/crypter.go

@@ -0,0 +1,535 @@
+/*-
+ * Copyright 2014 Square Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package jose
+
+import (
+	"crypto/ecdsa"
+	"crypto/rsa"
+	"errors"
+	"fmt"
+	"reflect"
+
+	"gopkg.in/square/go-jose.v2/json"
+)
+
+// Encrypter represents an encrypter which produces an encrypted JWE object.
+type Encrypter interface {
+	Encrypt(plaintext []byte) (*JSONWebEncryption, error)
+	EncryptWithAuthData(plaintext []byte, aad []byte) (*JSONWebEncryption, error)
+	Options() EncrypterOptions
+}
+
+// A generic content cipher
+type contentCipher interface {
+	keySize() int
+	encrypt(cek []byte, aad, plaintext []byte) (*aeadParts, error)
+	decrypt(cek []byte, aad []byte, parts *aeadParts) ([]byte, error)
+}
+
+// A key generator (for generating/getting a CEK)
+type keyGenerator interface {
+	keySize() int
+	genKey() ([]byte, rawHeader, error)
+}
+
+// A generic key encrypter
+type keyEncrypter interface {
+	encryptKey(cek []byte, alg KeyAlgorithm) (recipientInfo, error) // Encrypt a key
+}
+
+// A generic key decrypter
+type keyDecrypter interface {
+	decryptKey(headers rawHeader, recipient *recipientInfo, generator keyGenerator) ([]byte, error) // Decrypt a key
+}
+
+// A generic encrypter based on the given key encrypter and content cipher.
+type genericEncrypter struct {
+	contentAlg     ContentEncryption
+	compressionAlg CompressionAlgorithm
+	cipher         contentCipher
+	recipients     []recipientKeyInfo
+	keyGenerator   keyGenerator
+	extraHeaders   map[HeaderKey]interface{}
+}
+
+type recipientKeyInfo struct {
+	keyID        string
+	keyAlg       KeyAlgorithm
+	keyEncrypter keyEncrypter
+}
+
+// EncrypterOptions represents options that can be set on new encrypters.
+type EncrypterOptions struct {
+	Compression CompressionAlgorithm
+
+	// Optional map of additional keys to be inserted into the protected header
+	// of a JWS object. Some specifications which make use of JWS like to insert
+	// additional values here. All values must be JSON-serializable.
+	ExtraHeaders map[HeaderKey]interface{}
+}
+
+// WithHeader adds an arbitrary value to the ExtraHeaders map, initializing it
+// if necessary. It returns itself and so can be used in a fluent style.
+func (eo *EncrypterOptions) WithHeader(k HeaderKey, v interface{}) *EncrypterOptions {
+	if eo.ExtraHeaders == nil {
+		eo.ExtraHeaders = map[HeaderKey]interface{}{}
+	}
+	eo.ExtraHeaders[k] = v
+	return eo
+}
+
+// WithContentType adds a content type ("cty") header and returns the updated
+// EncrypterOptions.
+func (eo *EncrypterOptions) WithContentType(contentType ContentType) *EncrypterOptions {
+	return eo.WithHeader(HeaderContentType, contentType)
+}
+
+// WithType adds a type ("typ") header and returns the updated EncrypterOptions.
+func (eo *EncrypterOptions) WithType(typ ContentType) *EncrypterOptions {
+	return eo.WithHeader(HeaderType, typ)
+}
+
+// Recipient represents an algorithm/key to encrypt messages to.
+//
+// PBES2Count and PBES2Salt correspond with the  "p2c" and "p2s" headers used
+// on the password-based encryption algorithms PBES2-HS256+A128KW,
+// PBES2-HS384+A192KW, and PBES2-HS512+A256KW. If they are not provided a safe
+// default of 100000 will be used for the count and a 128-bit random salt will
+// be generated.
+type Recipient struct {
+	Algorithm  KeyAlgorithm
+	Key        interface{}
+	KeyID      string
+	PBES2Count int
+	PBES2Salt  []byte
+}
+
+// NewEncrypter creates an appropriate encrypter based on the key type
+func NewEncrypter(enc ContentEncryption, rcpt Recipient, opts *EncrypterOptions) (Encrypter, error) {
+	encrypter := &genericEncrypter{
+		contentAlg: enc,
+		recipients: []recipientKeyInfo{},
+		cipher:     getContentCipher(enc),
+	}
+	if opts != nil {
+		encrypter.compressionAlg = opts.Compression
+		encrypter.extraHeaders = opts.ExtraHeaders
+	}
+
+	if encrypter.cipher == nil {
+		return nil, ErrUnsupportedAlgorithm
+	}
+
+	var keyID string
+	var rawKey interface{}
+	switch encryptionKey := rcpt.Key.(type) {
+	case JSONWebKey:
+		keyID, rawKey = encryptionKey.KeyID, encryptionKey.Key
+	case *JSONWebKey:
+		keyID, rawKey = encryptionKey.KeyID, encryptionKey.Key
+	default:
+		rawKey = encryptionKey
+	}
+
+	switch rcpt.Algorithm {
+	case DIRECT:
+		// Direct encryption mode must be treated differently
+		if reflect.TypeOf(rawKey) != reflect.TypeOf([]byte{}) {
+			return nil, ErrUnsupportedKeyType
+		}
+		if encrypter.cipher.keySize() != len(rawKey.([]byte)) {
+			return nil, ErrInvalidKeySize
+		}
+		encrypter.keyGenerator = staticKeyGenerator{
+			key: rawKey.([]byte),
+		}
+		recipientInfo, _ := newSymmetricRecipient(rcpt.Algorithm, rawKey.([]byte))
+		recipientInfo.keyID = keyID
+		if rcpt.KeyID != "" {
+			recipientInfo.keyID = rcpt.KeyID
+		}
+		encrypter.recipients = []recipientKeyInfo{recipientInfo}
+		return encrypter, nil
+	case ECDH_ES:
+		// ECDH-ES (w/o key wrapping) is similar to DIRECT mode
+		typeOf := reflect.TypeOf(rawKey)
+		if typeOf != reflect.TypeOf(&ecdsa.PublicKey{}) {
+			return nil, ErrUnsupportedKeyType
+		}
+		encrypter.keyGenerator = ecKeyGenerator{
+			size:      encrypter.cipher.keySize(),
+			algID:     string(enc),
+			publicKey: rawKey.(*ecdsa.PublicKey),
+		}
+		recipientInfo, _ := newECDHRecipient(rcpt.Algorithm, rawKey.(*ecdsa.PublicKey))
+		recipientInfo.keyID = keyID
+		if rcpt.KeyID != "" {
+			recipientInfo.keyID = rcpt.KeyID
+		}
+		encrypter.recipients = []recipientKeyInfo{recipientInfo}
+		return encrypter, nil
+	default:
+		// Can just add a standard recipient
+		encrypter.keyGenerator = randomKeyGenerator{
+			size: encrypter.cipher.keySize(),
+		}
+		err := encrypter.addRecipient(rcpt)
+		return encrypter, err
+	}
+}
+
+// NewMultiEncrypter creates a multi-encrypter based on the given parameters
+func NewMultiEncrypter(enc ContentEncryption, rcpts []Recipient, opts *EncrypterOptions) (Encrypter, error) {
+	cipher := getContentCipher(enc)
+
+	if cipher == nil {
+		return nil, ErrUnsupportedAlgorithm
+	}
+	if rcpts == nil || len(rcpts) == 0 {
+		return nil, fmt.Errorf("square/go-jose: recipients is nil or empty")
+	}
+
+	encrypter := &genericEncrypter{
+		contentAlg: enc,
+		recipients: []recipientKeyInfo{},
+		cipher:     cipher,
+		keyGenerator: randomKeyGenerator{
+			size: cipher.keySize(),
+		},
+	}
+
+	if opts != nil {
+		encrypter.compressionAlg = opts.Compression
+	}
+
+	for _, recipient := range rcpts {
+		err := encrypter.addRecipient(recipient)
+		if err != nil {
+			return nil, err
+		}
+	}
+
+	return encrypter, nil
+}
+
+func (ctx *genericEncrypter) addRecipient(recipient Recipient) (err error) {
+	var recipientInfo recipientKeyInfo
+
+	switch recipient.Algorithm {
+	case DIRECT, ECDH_ES:
+		return fmt.Errorf("square/go-jose: key algorithm '%s' not supported in multi-recipient mode", recipient.Algorithm)
+	}
+
+	recipientInfo, err = makeJWERecipient(recipient.Algorithm, recipient.Key)
+	if recipient.KeyID != "" {
+		recipientInfo.keyID = recipient.KeyID
+	}
+
+	switch recipient.Algorithm {
+	case PBES2_HS256_A128KW, PBES2_HS384_A192KW, PBES2_HS512_A256KW:
+		if sr, ok := recipientInfo.keyEncrypter.(*symmetricKeyCipher); ok {
+			sr.p2c = recipient.PBES2Count
+			sr.p2s = recipient.PBES2Salt
+		}
+	}
+
+	if err == nil {
+		ctx.recipients = append(ctx.recipients, recipientInfo)
+	}
+	return err
+}
+
+func makeJWERecipient(alg KeyAlgorithm, encryptionKey interface{}) (recipientKeyInfo, error) {
+	switch encryptionKey := encryptionKey.(type) {
+	case *rsa.PublicKey:
+		return newRSARecipient(alg, encryptionKey)
+	case *ecdsa.PublicKey:
+		return newECDHRecipient(alg, encryptionKey)
+	case []byte:
+		return newSymmetricRecipient(alg, encryptionKey)
+	case string:
+		return newSymmetricRecipient(alg, []byte(encryptionKey))
+	case *JSONWebKey:
+		recipient, err := makeJWERecipient(alg, encryptionKey.Key)
+		recipient.keyID = encryptionKey.KeyID
+		return recipient, err
+	default:
+		return recipientKeyInfo{}, ErrUnsupportedKeyType
+	}
+}
+
+// newDecrypter creates an appropriate decrypter based on the key type
+func newDecrypter(decryptionKey interface{}) (keyDecrypter, error) {
+	switch decryptionKey := decryptionKey.(type) {
+	case *rsa.PrivateKey:
+		return &rsaDecrypterSigner{
+			privateKey: decryptionKey,
+		}, nil
+	case *ecdsa.PrivateKey:
+		return &ecDecrypterSigner{
+			privateKey: decryptionKey,
+		}, nil
+	case []byte:
+		return &symmetricKeyCipher{
+			key: decryptionKey,
+		}, nil
+	case string:
+		return &symmetricKeyCipher{
+			key: []byte(decryptionKey),
+		}, nil
+	case JSONWebKey:
+		return newDecrypter(decryptionKey.Key)
+	case *JSONWebKey:
+		return newDecrypter(decryptionKey.Key)
+	default:
+		return nil, ErrUnsupportedKeyType
+	}
+}
+
+// Implementation of encrypt method producing a JWE object.
+func (ctx *genericEncrypter) Encrypt(plaintext []byte) (*JSONWebEncryption, error) {
+	return ctx.EncryptWithAuthData(plaintext, nil)
+}
+
+// Implementation of encrypt method producing a JWE object.
+func (ctx *genericEncrypter) EncryptWithAuthData(plaintext, aad []byte) (*JSONWebEncryption, error) {
+	obj := &JSONWebEncryption{}
+	obj.aad = aad
+
+	obj.protected = &rawHeader{}
+	err := obj.protected.set(headerEncryption, ctx.contentAlg)
+	if err != nil {
+		return nil, err
+	}
+
+	obj.recipients = make([]recipientInfo, len(ctx.recipients))
+
+	if len(ctx.recipients) == 0 {
+		return nil, fmt.Errorf("square/go-jose: no recipients to encrypt to")
+	}
+
+	cek, headers, err := ctx.keyGenerator.genKey()
+	if err != nil {
+		return nil, err
+	}
+
+	obj.protected.merge(&headers)
+
+	for i, info := range ctx.recipients {
+		recipient, err := info.keyEncrypter.encryptKey(cek, info.keyAlg)
+		if err != nil {
+			return nil, err
+		}
+
+		err = recipient.header.set(headerAlgorithm, info.keyAlg)
+		if err != nil {
+			return nil, err
+		}
+
+		if info.keyID != "" {
+			err = recipient.header.set(headerKeyID, info.keyID)
+			if err != nil {
+				return nil, err
+			}
+		}
+		obj.recipients[i] = recipient
+	}
+
+	if len(ctx.recipients) == 1 {
+		// Move per-recipient headers into main protected header if there's
+		// only a single recipient.
+		obj.protected.merge(obj.recipients[0].header)
+		obj.recipients[0].header = nil
+	}
+
+	if ctx.compressionAlg != NONE {
+		plaintext, err = compress(ctx.compressionAlg, plaintext)
+		if err != nil {
+			return nil, err
+		}
+
+		err = obj.protected.set(headerCompression, ctx.compressionAlg)
+		if err != nil {
+			return nil, err
+		}
+	}
+
+	for k, v := range ctx.extraHeaders {
+		b, err := json.Marshal(v)
+		if err != nil {
+			return nil, err
+		}
+		(*obj.protected)[k] = makeRawMessage(b)
+	}
+
+	authData := obj.computeAuthData()
+	parts, err := ctx.cipher.encrypt(cek, authData, plaintext)
+	if err != nil {
+		return nil, err
+	}
+
+	obj.iv = parts.iv
+	obj.ciphertext = parts.ciphertext
+	obj.tag = parts.tag
+
+	return obj, nil
+}
+
+func (ctx *genericEncrypter) Options() EncrypterOptions {
+	return EncrypterOptions{
+		Compression:  ctx.compressionAlg,
+		ExtraHeaders: ctx.extraHeaders,
+	}
+}
+
+// Decrypt and validate the object and return the plaintext. Note that this
+// function does not support multi-recipient, if you desire multi-recipient
+// decryption use DecryptMulti instead.
+func (obj JSONWebEncryption) Decrypt(decryptionKey interface{}) ([]byte, error) {
+	headers := obj.mergedHeaders(nil)
+
+	if len(obj.recipients) > 1 {
+		return nil, errors.New("square/go-jose: too many recipients in payload; expecting only one")
+	}
+
+	critical, err := headers.getCritical()
+	if err != nil {
+		return nil, fmt.Errorf("square/go-jose: invalid crit header")
+	}
+
+	if len(critical) > 0 {
+		return nil, fmt.Errorf("square/go-jose: unsupported crit header")
+	}
+
+	decrypter, err := newDecrypter(decryptionKey)
+	if err != nil {
+		return nil, err
+	}
+
+	cipher := getContentCipher(headers.getEncryption())
+	if cipher == nil {
+		return nil, fmt.Errorf("square/go-jose: unsupported enc value '%s'", string(headers.getEncryption()))
+	}
+
+	generator := randomKeyGenerator{
+		size: cipher.keySize(),
+	}
+
+	parts := &aeadParts{
+		iv:         obj.iv,
+		ciphertext: obj.ciphertext,
+		tag:        obj.tag,
+	}
+
+	authData := obj.computeAuthData()
+
+	var plaintext []byte
+	recipient := obj.recipients[0]
+	recipientHeaders := obj.mergedHeaders(&recipient)
+
+	cek, err := decrypter.decryptKey(recipientHeaders, &recipient, generator)
+	if err == nil {
+		// Found a valid CEK -- let's try to decrypt.
+		plaintext, err = cipher.decrypt(cek, authData, parts)
+	}
+
+	if plaintext == nil {
+		return nil, ErrCryptoFailure
+	}
+
+	// The "zip" header parameter may only be present in the protected header.
+	if comp := obj.protected.getCompression(); comp != "" {
+		plaintext, err = decompress(comp, plaintext)
+	}
+
+	return plaintext, err
+}
+
+// DecryptMulti decrypts and validates the object and returns the plaintexts,
+// with support for multiple recipients. It returns the index of the recipient
+// for which the decryption was successful, the merged headers for that recipient,
+// and the plaintext.
+func (obj JSONWebEncryption) DecryptMulti(decryptionKey interface{}) (int, Header, []byte, error) {
+	globalHeaders := obj.mergedHeaders(nil)
+
+	critical, err := globalHeaders.getCritical()
+	if err != nil {
+		return -1, Header{}, nil, fmt.Errorf("square/go-jose: invalid crit header")
+	}
+
+	if len(critical) > 0 {
+		return -1, Header{}, nil, fmt.Errorf("square/go-jose: unsupported crit header")
+	}
+
+	decrypter, err := newDecrypter(decryptionKey)
+	if err != nil {
+		return -1, Header{}, nil, err
+	}
+
+	encryption := globalHeaders.getEncryption()
+	cipher := getContentCipher(encryption)
+	if cipher == nil {
+		return -1, Header{}, nil, fmt.Errorf("square/go-jose: unsupported enc value '%s'", string(encryption))
+	}
+
+	generator := randomKeyGenerator{
+		size: cipher.keySize(),
+	}
+
+	parts := &aeadParts{
+		iv:         obj.iv,
+		ciphertext: obj.ciphertext,
+		tag:        obj.tag,
+	}
+
+	authData := obj.computeAuthData()
+
+	index := -1
+	var plaintext []byte
+	var headers rawHeader
+
+	for i, recipient := range obj.recipients {
+		recipientHeaders := obj.mergedHeaders(&recipient)
+
+		cek, err := decrypter.decryptKey(recipientHeaders, &recipient, generator)
+		if err == nil {
+			// Found a valid CEK -- let's try to decrypt.
+			plaintext, err = cipher.decrypt(cek, authData, parts)
+			if err == nil {
+				index = i
+				headers = recipientHeaders
+				break
+			}
+		}
+	}
+
+	if plaintext == nil || err != nil {
+		return -1, Header{}, nil, ErrCryptoFailure
+	}
+
+	// The "zip" header parameter may only be present in the protected header.
+	if comp := obj.protected.getCompression(); comp != "" {
+		plaintext, err = decompress(comp, plaintext)
+	}
+
+	sanitized, err := headers.sanitized()
+	if err != nil {
+		return -1, Header{}, nil, fmt.Errorf("square/go-jose: failed to sanitize header: %v", err)
+	}
+
+	return index, sanitized, plaintext, err
+}

src/vendor/gopkg.in/square/go-jose.v2/doc.go

@@ -0,0 +1,27 @@
+/*-
+ * Copyright 2014 Square Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+/*
+
+Package jose aims to provide an implementation of the Javascript Object Signing
+and Encryption set of standards. It implements encryption and signing based on
+the JSON Web Encryption and JSON Web Signature standards, with optional JSON
+Web Token support available in a sub-package. The library supports both the
+compact and full serialization formats, and has optional support for multiple
+recipients.
+
+*/
+package jose

src/vendor/gopkg.in/square/go-jose.v2/encoding.go

@@ -0,0 +1,179 @@
+/*-
+ * Copyright 2014 Square Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package jose
+
+import (
+	"bytes"
+	"compress/flate"
+	"encoding/base64"
+	"encoding/binary"
+	"io"
+	"math/big"
+	"regexp"
+
+	"gopkg.in/square/go-jose.v2/json"
+)
+
+var stripWhitespaceRegex = regexp.MustCompile("\\s")
+
+// Helper function to serialize known-good objects.
+// Precondition: value is not a nil pointer.
+func mustSerializeJSON(value interface{}) []byte {
+	out, err := json.Marshal(value)
+	if err != nil {
+		panic(err)
+	}
+	// We never want to serialize the top-level value "null," since it's not a
+	// valid JOSE message. But if a caller passes in a nil pointer to this method,
+	// MarshalJSON will happily serialize it as the top-level value "null". If
+	// that value is then embedded in another operation, for instance by being
+	// base64-encoded and fed as input to a signing algorithm
+	// (https://github.com/square/go-jose/issues/22), the result will be
+	// incorrect. Because this method is intended for known-good objects, and a nil
+	// pointer is not a known-good object, we are free to panic in this case.
+	// Note: It's not possible to directly check whether the data pointed at by an
+	// interface is a nil pointer, so we do this hacky workaround.
+	// https://groups.google.com/forum/#!topic/golang-nuts/wnH302gBa4I
+	if string(out) == "null" {
+		panic("Tried to serialize a nil pointer.")
+	}
+	return out
+}
+
+// Strip all newlines and whitespace
+func stripWhitespace(data string) string {
+	return stripWhitespaceRegex.ReplaceAllString(data, "")
+}
+
+// Perform compression based on algorithm
+func compress(algorithm CompressionAlgorithm, input []byte) ([]byte, error) {
+	switch algorithm {
+	case DEFLATE:
+		return deflate(input)
+	default:
+		return nil, ErrUnsupportedAlgorithm
+	}
+}
+
+// Perform decompression based on algorithm
+func decompress(algorithm CompressionAlgorithm, input []byte) ([]byte, error) {
+	switch algorithm {
+	case DEFLATE:
+		return inflate(input)
+	default:
+		return nil, ErrUnsupportedAlgorithm
+	}
+}
+
+// Compress with DEFLATE
+func deflate(input []byte) ([]byte, error) {
+	output := new(bytes.Buffer)
+
+	// Writing to byte buffer, err is always nil
+	writer, _ := flate.NewWriter(output, 1)
+	_, _ = io.Copy(writer, bytes.NewBuffer(input))
+
+	err := writer.Close()
+	return output.Bytes(), err
+}
+
+// Decompress with DEFLATE
+func inflate(input []byte) ([]byte, error) {
+	output := new(bytes.Buffer)
+	reader := flate.NewReader(bytes.NewBuffer(input))
+
+	_, err := io.Copy(output, reader)
+	if err != nil {
+		return nil, err
+	}
+
+	err = reader.Close()
+	return output.Bytes(), err
+}
+
+// byteBuffer represents a slice of bytes that can be serialized to url-safe base64.
+type byteBuffer struct {
+	data []byte
+}
+
+func newBuffer(data []byte) *byteBuffer {
+	if data == nil {
+		return nil
+	}
+	return &byteBuffer{
+		data: data,
+	}
+}
+
+func newFixedSizeBuffer(data []byte, length int) *byteBuffer {
+	if len(data) > length {
+		panic("square/go-jose: invalid call to newFixedSizeBuffer (len(data) > length)")
+	}
+	pad := make([]byte, length-len(data))
+	return newBuffer(append(pad, data...))
+}
+
+func newBufferFromInt(num uint64) *byteBuffer {
+	data := make([]byte, 8)
+	binary.BigEndian.PutUint64(data, num)
+	return newBuffer(bytes.TrimLeft(data, "\x00"))
+}
+
+func (b *byteBuffer) MarshalJSON() ([]byte, error) {
+	return json.Marshal(b.base64())
+}
+
+func (b *byteBuffer) UnmarshalJSON(data []byte) error {
+	var encoded string
+	err := json.Unmarshal(data, &encoded)
+	if err != nil {
+		return err
+	}
+
+	if encoded == "" {
+		return nil
+	}
+
+	decoded, err := base64.RawURLEncoding.DecodeString(encoded)
+	if err != nil {
+		return err
+	}
+
+	*b = *newBuffer(decoded)
+
+	return nil
+}
+
+func (b *byteBuffer) base64() string {
+	return base64.RawURLEncoding.EncodeToString(b.data)
+}
+
+func (b *byteBuffer) bytes() []byte {
+	// Handling nil here allows us to transparently handle nil slices when serializing.
+	if b == nil {
+		return nil
+	}
+	return b.data
+}
+
+func (b byteBuffer) bigInt() *big.Int {
+	return new(big.Int).SetBytes(b.data)
+}
+
+func (b byteBuffer) toInt() int {
+	return int(b.bigInt().Int64())
+}

src/vendor/gopkg.in/square/go-jose.v2/json/LICENSE

@@ -0,0 +1,27 @@
+Copyright (c) 2012 The Go Authors. All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are
+met:
+
+   * Redistributions of source code must retain the above copyright
+notice, this list of conditions and the following disclaimer.
+   * Redistributions in binary form must reproduce the above
+copyright notice, this list of conditions and the following disclaimer
+in the documentation and/or other materials provided with the
+distribution.
+   * Neither the name of Google Inc. nor the names of its
+contributors may be used to endorse or promote products derived from
+this software without specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

src/vendor/gopkg.in/square/go-jose.v2/json/README.md

@@ -0,0 +1,13 @@
+# Safe JSON
+
+This repository contains a fork of the `encoding/json` package from Go 1.6.
+
+The following changes were made:
+
+* Object deserialization uses case-sensitive member name matching instead of
+  [case-insensitive matching](https://www.ietf.org/mail-archive/web/json/current/msg03763.html).
+  This is to avoid differences in the interpretation of JOSE messages between
+  go-jose and libraries written in other languages.
+* When deserializing a JSON object, we check for duplicate keys and reject the
+  input whenever we detect a duplicate. Rather than trying to work with malformed
+  data, we prefer to reject it right away.

src/vendor/gopkg.in/square/go-jose.v2/json/indent.go

@@ -0,0 +1,141 @@
+// Copyright 2010 The Go Authors.  All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package json
+
+import "bytes"
+
+// Compact appends to dst the JSON-encoded src with
+// insignificant space characters elided.
+func Compact(dst *bytes.Buffer, src []byte) error {
+	return compact(dst, src, false)
+}
+
+func compact(dst *bytes.Buffer, src []byte, escape bool) error {
+	origLen := dst.Len()
+	var scan scanner
+	scan.reset()
+	start := 0
+	for i, c := range src {
+		if escape && (c == '<' || c == '>' || c == '&') {
+			if start < i {
+				dst.Write(src[start:i])
+			}
+			dst.WriteString(`\u00`)
+			dst.WriteByte(hex[c>>4])
+			dst.WriteByte(hex[c&0xF])
+			start = i + 1
+		}
+		// Convert U+2028 and U+2029 (E2 80 A8 and E2 80 A9).
+		if c == 0xE2 && i+2 < len(src) && src[i+1] == 0x80 && src[i+2]&^1 == 0xA8 {
+			if start < i {
+				dst.Write(src[start:i])
+			}
+			dst.WriteString(`\u202`)
+			dst.WriteByte(hex[src[i+2]&0xF])
+			start = i + 3
+		}
+		v := scan.step(&scan, c)
+		if v >= scanSkipSpace {
+			if v == scanError {
+				break
+			}
+			if start < i {
+				dst.Write(src[start:i])
+			}
+			start = i + 1
+		}
+	}
+	if scan.eof() == scanError {
+		dst.Truncate(origLen)
+		return scan.err
+	}
+	if start < len(src) {
+		dst.Write(src[start:])
+	}
+	return nil
+}
+
+func newline(dst *bytes.Buffer, prefix, indent string, depth int) {
+	dst.WriteByte('\n')
+	dst.WriteString(prefix)
+	for i := 0; i < depth; i++ {
+		dst.WriteString(indent)
+	}
+}
+
+// Indent appends to dst an indented form of the JSON-encoded src.
+// Each element in a JSON object or array begins on a new,
+// indented line beginning with prefix followed by one or more
+// copies of indent according to the indentation nesting.
+// The data appended to dst does not begin with the prefix nor
+// any indentation, to make it easier to embed inside other formatted JSON data.
+// Although leading space characters (space, tab, carriage return, newline)
+// at the beginning of src are dropped, trailing space characters
+// at the end of src are preserved and copied to dst.
+// For example, if src has no trailing spaces, neither will dst;
+// if src ends in a trailing newline, so will dst.
+func Indent(dst *bytes.Buffer, src []byte, prefix, indent string) error {
+	origLen := dst.Len()
+	var scan scanner
+	scan.reset()
+	needIndent := false
+	depth := 0
+	for _, c := range src {
+		scan.bytes++
+		v := scan.step(&scan, c)
+		if v == scanSkipSpace {
+			continue
+		}
+		if v == scanError {
+			break
+		}
+		if needIndent && v != scanEndObject && v != scanEndArray {
+			needIndent = false
+			depth++
+			newline(dst, prefix, indent, depth)
+		}
+
+		// Emit semantically uninteresting bytes
+		// (in particular, punctuation in strings) unmodified.
+		if v == scanContinue {
+			dst.WriteByte(c)
+			continue
+		}
+
+		// Add spacing around real punctuation.
+		switch c {
+		case '{', '[':
+			// delay indent so that empty object and array are formatted as {} and [].
+			needIndent = true
+			dst.WriteByte(c)
+
+		case ',':
+			dst.WriteByte(c)
+			newline(dst, prefix, indent, depth)
+
+		case ':':
+			dst.WriteByte(c)
+			dst.WriteByte(' ')
+
+		case '}', ']':
+			if needIndent {
+				// suppress indent in empty object/array
+				needIndent = false
+			} else {
+				depth--
+				newline(dst, prefix, indent, depth)
+			}
+			dst.WriteByte(c)
+
+		default:
+			dst.WriteByte(c)
+		}
+	}
+	if scan.eof() == scanError {
+		dst.Truncate(origLen)
+		return scan.err
+	}
+	return nil
+}

src/vendor/gopkg.in/square/go-jose.v2/json/scanner.go

@@ -0,0 +1,623 @@
+// Copyright 2010 The Go Authors.  All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package json
+
+// JSON value parser state machine.
+// Just about at the limit of what is reasonable to write by hand.
+// Some parts are a bit tedious, but overall it nicely factors out the
+// otherwise common code from the multiple scanning functions
+// in this package (Compact, Indent, checkValid, nextValue, etc).
+//
+// This file starts with two simple examples using the scanner
+// before diving into the scanner itself.
+
+import "strconv"
+
+// checkValid verifies that data is valid JSON-encoded data.
+// scan is passed in for use by checkValid to avoid an allocation.
+func checkValid(data []byte, scan *scanner) error {
+	scan.reset()
+	for _, c := range data {
+		scan.bytes++
+		if scan.step(scan, c) == scanError {
+			return scan.err
+		}
+	}
+	if scan.eof() == scanError {
+		return scan.err
+	}
+	return nil
+}
+
+// nextValue splits data after the next whole JSON value,
+// returning that value and the bytes that follow it as separate slices.
+// scan is passed in for use by nextValue to avoid an allocation.
+func nextValue(data []byte, scan *scanner) (value, rest []byte, err error) {
+	scan.reset()
+	for i, c := range data {
+		v := scan.step(scan, c)
+		if v >= scanEndObject {
+			switch v {
+			// probe the scanner with a space to determine whether we will
+			// get scanEnd on the next character. Otherwise, if the next character
+			// is not a space, scanEndTop allocates a needless error.
+			case scanEndObject, scanEndArray:
+				if scan.step(scan, ' ') == scanEnd {
+					return data[:i+1], data[i+1:], nil
+				}
+			case scanError:
+				return nil, nil, scan.err
+			case scanEnd:
+				return data[:i], data[i:], nil
+			}
+		}
+	}
+	if scan.eof() == scanError {
+		return nil, nil, scan.err
+	}
+	return data, nil, nil
+}
+
+// A SyntaxError is a description of a JSON syntax error.
+type SyntaxError struct {
+	msg    string // description of error
+	Offset int64  // error occurred after reading Offset bytes
+}
+
+func (e *SyntaxError) Error() string { return e.msg }
+
+// A scanner is a JSON scanning state machine.
+// Callers call scan.reset() and then pass bytes in one at a time
+// by calling scan.step(&scan, c) for each byte.
+// The return value, referred to as an opcode, tells the
+// caller about significant parsing events like beginning
+// and ending literals, objects, and arrays, so that the
+// caller can follow along if it wishes.
+// The return value scanEnd indicates that a single top-level
+// JSON value has been completed, *before* the byte that
+// just got passed in.  (The indication must be delayed in order
+// to recognize the end of numbers: is 123 a whole value or
+// the beginning of 12345e+6?).
+type scanner struct {
+	// The step is a func to be called to execute the next transition.
+	// Also tried using an integer constant and a single func
+	// with a switch, but using the func directly was 10% faster
+	// on a 64-bit Mac Mini, and it's nicer to read.
+	step func(*scanner, byte) int
+
+	// Reached end of top-level value.
+	endTop bool
+
+	// Stack of what we're in the middle of - array values, object keys, object values.
+	parseState []int
+
+	// Error that happened, if any.
+	err error
+
+	// 1-byte redo (see undo method)
+	redo      bool
+	redoCode  int
+	redoState func(*scanner, byte) int
+
+	// total bytes consumed, updated by decoder.Decode
+	bytes int64
+}
+
+// These values are returned by the state transition functions
+// assigned to scanner.state and the method scanner.eof.
+// They give details about the current state of the scan that
+// callers might be interested to know about.
+// It is okay to ignore the return value of any particular
+// call to scanner.state: if one call returns scanError,
+// every subsequent call will return scanError too.
+const (
+	// Continue.
+	scanContinue     = iota // uninteresting byte
+	scanBeginLiteral        // end implied by next result != scanContinue
+	scanBeginObject         // begin object
+	scanObjectKey           // just finished object key (string)
+	scanObjectValue         // just finished non-last object value
+	scanEndObject           // end object (implies scanObjectValue if possible)
+	scanBeginArray          // begin array
+	scanArrayValue          // just finished array value
+	scanEndArray            // end array (implies scanArrayValue if possible)
+	scanSkipSpace           // space byte; can skip; known to be last "continue" result
+
+	// Stop.
+	scanEnd   // top-level value ended *before* this byte; known to be first "stop" result
+	scanError // hit an error, scanner.err.
+)
+
+// These values are stored in the parseState stack.
+// They give the current state of a composite value
+// being scanned.  If the parser is inside a nested value
+// the parseState describes the nested state, outermost at entry 0.
+const (
+	parseObjectKey   = iota // parsing object key (before colon)
+	parseObjectValue        // parsing object value (after colon)
+	parseArrayValue         // parsing array value
+)
+
+// reset prepares the scanner for use.
+// It must be called before calling s.step.
+func (s *scanner) reset() {
+	s.step = stateBeginValue
+	s.parseState = s.parseState[0:0]
+	s.err = nil
+	s.redo = false
+	s.endTop = false
+}
+
+// eof tells the scanner that the end of input has been reached.
+// It returns a scan status just as s.step does.
+func (s *scanner) eof() int {
+	if s.err != nil {
+		return scanError
+	}
+	if s.endTop {
+		return scanEnd
+	}
+	s.step(s, ' ')
+	if s.endTop {
+		return scanEnd
+	}
+	if s.err == nil {
+		s.err = &SyntaxError{"unexpected end of JSON input", s.bytes}
+	}
+	return scanError
+}
+
+// pushParseState pushes a new parse state p onto the parse stack.
+func (s *scanner) pushParseState(p int) {
+	s.parseState = append(s.parseState, p)
+}
+
+// popParseState pops a parse state (already obtained) off the stack
+// and updates s.step accordingly.
+func (s *scanner) popParseState() {
+	n := len(s.parseState) - 1
+	s.parseState = s.parseState[0:n]
+	s.redo = false
+	if n == 0 {
+		s.step = stateEndTop
+		s.endTop = true
+	} else {
+		s.step = stateEndValue
+	}
+}
+
+func isSpace(c byte) bool {
+	return c == ' ' || c == '\t' || c == '\r' || c == '\n'
+}
+
+// stateBeginValueOrEmpty is the state after reading `[`.
+func stateBeginValueOrEmpty(s *scanner, c byte) int {
+	if c <= ' ' && isSpace(c) {
+		return scanSkipSpace
+	}
+	if c == ']' {
+		return stateEndValue(s, c)
+	}
+	return stateBeginValue(s, c)
+}
+
+// stateBeginValue is the state at the beginning of the input.
+func stateBeginValue(s *scanner, c byte) int {
+	if c <= ' ' && isSpace(c) {
+		return scanSkipSpace
+	}
+	switch c {
+	case '{':
+		s.step = stateBeginStringOrEmpty
+		s.pushParseState(parseObjectKey)
+		return scanBeginObject
+	case '[':
+		s.step = stateBeginValueOrEmpty
+		s.pushParseState(parseArrayValue)
+		return scanBeginArray
+	case '"':
+		s.step = stateInString
+		return scanBeginLiteral
+	case '-':
+		s.step = stateNeg
+		return scanBeginLiteral
+	case '0': // beginning of 0.123
+		s.step = state0
+		return scanBeginLiteral
+	case 't': // beginning of true
+		s.step = stateT
+		return scanBeginLiteral
+	case 'f': // beginning of false
+		s.step = stateF
+		return scanBeginLiteral
+	case 'n': // beginning of null
+		s.step = stateN
+		return scanBeginLiteral
+	}
+	if '1' <= c && c <= '9' { // beginning of 1234.5
+		s.step = state1
+		return scanBeginLiteral
+	}
+	return s.error(c, "looking for beginning of value")
+}
+
+// stateBeginStringOrEmpty is the state after reading `{`.
+func stateBeginStringOrEmpty(s *scanner, c byte) int {
+	if c <= ' ' && isSpace(c) {
+		return scanSkipSpace
+	}
+	if c == '}' {
+		n := len(s.parseState)
+		s.parseState[n-1] = parseObjectValue
+		return stateEndValue(s, c)
+	}
+	return stateBeginString(s, c)
+}
+
+// stateBeginString is the state after reading `{"key": value,`.
+func stateBeginString(s *scanner, c byte) int {
+	if c <= ' ' && isSpace(c) {
+		return scanSkipSpace
+	}
+	if c == '"' {
+		s.step = stateInString
+		return scanBeginLiteral
+	}
+	return s.error(c, "looking for beginning of object key string")
+}
+
+// stateEndValue is the state after completing a value,
+// such as after reading `{}` or `true` or `["x"`.
+func stateEndValue(s *scanner, c byte) int {
+	n := len(s.parseState)
+	if n == 0 {
+		// Completed top-level before the current byte.
+		s.step = stateEndTop
+		s.endTop = true
+		return stateEndTop(s, c)
+	}
+	if c <= ' ' && isSpace(c) {
+		s.step = stateEndValue
+		return scanSkipSpace
+	}
+	ps := s.parseState[n-1]
+	switch ps {
+	case parseObjectKey:
+		if c == ':' {
+			s.parseState[n-1] = parseObjectValue
+			s.step = stateBeginValue
+			return scanObjectKey
+		}
+		return s.error(c, "after object key")
+	case parseObjectValue:
+		if c == ',' {
+			s.parseState[n-1] = parseObjectKey
+			s.step = stateBeginString
+			return scanObjectValue
+		}
+		if c == '}' {
+			s.popParseState()
+			return scanEndObject
+		}
+		return s.error(c, "after object key:value pair")
+	case parseArrayValue:
+		if c == ',' {
+			s.step = stateBeginValue
+			return scanArrayValue
+		}
+		if c == ']' {
+			s.popParseState()
+			return scanEndArray
+		}
+		return s.error(c, "after array element")
+	}
+	return s.error(c, "")
+}
+
+// stateEndTop is the state after finishing the top-level value,
+// such as after reading `{}` or `[1,2,3]`.
+// Only space characters should be seen now.
+func stateEndTop(s *scanner, c byte) int {
+	if c != ' ' && c != '\t' && c != '\r' && c != '\n' {
+		// Complain about non-space byte on next call.
+		s.error(c, "after top-level value")
+	}
+	return scanEnd
+}
+
+// stateInString is the state after reading `"`.
+func stateInString(s *scanner, c byte) int {
+	if c == '"' {
+		s.step = stateEndValue
+		return scanContinue
+	}
+	if c == '\\' {
+		s.step = stateInStringEsc
+		return scanContinue
+	}
+	if c < 0x20 {
+		return s.error(c, "in string literal")
+	}
+	return scanContinue
+}
+
+// stateInStringEsc is the state after reading `"\` during a quoted string.
+func stateInStringEsc(s *scanner, c byte) int {
+	switch c {
+	case 'b', 'f', 'n', 'r', 't', '\\', '/', '"':
+		s.step = stateInString
+		return scanContinue
+	case 'u':
+		s.step = stateInStringEscU
+		return scanContinue
+	}
+	return s.error(c, "in string escape code")
+}
+
+// stateInStringEscU is the state after reading `"\u` during a quoted string.
+func stateInStringEscU(s *scanner, c byte) int {
+	if '0' <= c && c <= '9' || 'a' <= c && c <= 'f' || 'A' <= c && c <= 'F' {
+		s.step = stateInStringEscU1
+		return scanContinue
+	}
+	// numbers
+	return s.error(c, "in \\u hexadecimal character escape")
+}
+
+// stateInStringEscU1 is the state after reading `"\u1` during a quoted string.
+func stateInStringEscU1(s *scanner, c byte) int {
+	if '0' <= c && c <= '9' || 'a' <= c && c <= 'f' || 'A' <= c && c <= 'F' {
+		s.step = stateInStringEscU12
+		return scanContinue
+	}
+	// numbers
+	return s.error(c, "in \\u hexadecimal character escape")
+}
+
+// stateInStringEscU12 is the state after reading `"\u12` during a quoted string.
+func stateInStringEscU12(s *scanner, c byte) int {
+	if '0' <= c && c <= '9' || 'a' <= c && c <= 'f' || 'A' <= c && c <= 'F' {
+		s.step = stateInStringEscU123
+		return scanContinue
+	}
+	// numbers
+	return s.error(c, "in \\u hexadecimal character escape")
+}
+
+// stateInStringEscU123 is the state after reading `"\u123` during a quoted string.
+func stateInStringEscU123(s *scanner, c byte) int {
+	if '0' <= c && c <= '9' || 'a' <= c && c <= 'f' || 'A' <= c && c <= 'F' {
+		s.step = stateInString
+		return scanContinue
+	}
+	// numbers
+	return s.error(c, "in \\u hexadecimal character escape")
+}
+
+// stateNeg is the state after reading `-` during a number.
+func stateNeg(s *scanner, c byte) int {
+	if c == '0' {
+		s.step = state0
+		return scanContinue
+	}
+	if '1' <= c && c <= '9' {
+		s.step = state1
+		return scanContinue
+	}
+	return s.error(c, "in numeric literal")
+}
+
+// state1 is the state after reading a non-zero integer during a number,
+// such as after reading `1` or `100` but not `0`.
+func state1(s *scanner, c byte) int {
+	if '0' <= c && c <= '9' {
+		s.step = state1
+		return scanContinue
+	}
+	return state0(s, c)
+}
+
+// state0 is the state after reading `0` during a number.
+func state0(s *scanner, c byte) int {
+	if c == '.' {
+		s.step = stateDot
+		return scanContinue
+	}
+	if c == 'e' || c == 'E' {
+		s.step = stateE
+		return scanContinue
+	}
+	return stateEndValue(s, c)
+}
+
+// stateDot is the state after reading the integer and decimal point in a number,
+// such as after reading `1.`.
+func stateDot(s *scanner, c byte) int {
+	if '0' <= c && c <= '9' {
+		s.step = stateDot0
+		return scanContinue
+	}
+	return s.error(c, "after decimal point in numeric literal")
+}
+
+// stateDot0 is the state after reading the integer, decimal point, and subsequent
+// digits of a number, such as after reading `3.14`.
+func stateDot0(s *scanner, c byte) int {
+	if '0' <= c && c <= '9' {
+		return scanContinue
+	}
+	if c == 'e' || c == 'E' {
+		s.step = stateE
+		return scanContinue
+	}
+	return stateEndValue(s, c)
+}
+
+// stateE is the state after reading the mantissa and e in a number,
+// such as after reading `314e` or `0.314e`.
+func stateE(s *scanner, c byte) int {
+	if c == '+' || c == '-' {
+		s.step = stateESign
+		return scanContinue
+	}
+	return stateESign(s, c)
+}
+
+// stateESign is the state after reading the mantissa, e, and sign in a number,
+// such as after reading `314e-` or `0.314e+`.
+func stateESign(s *scanner, c byte) int {
+	if '0' <= c && c <= '9' {
+		s.step = stateE0
+		return scanContinue
+	}
+	return s.error(c, "in exponent of numeric literal")
+}
+
+// stateE0 is the state after reading the mantissa, e, optional sign,
+// and at least one digit of the exponent in a number,
+// such as after reading `314e-2` or `0.314e+1` or `3.14e0`.
+func stateE0(s *scanner, c byte) int {
+	if '0' <= c && c <= '9' {
+		return scanContinue
+	}
+	return stateEndValue(s, c)
+}
+
+// stateT is the state after reading `t`.
+func stateT(s *scanner, c byte) int {
+	if c == 'r' {
+		s.step = stateTr
+		return scanContinue
+	}
+	return s.error(c, "in literal true (expecting 'r')")
+}
+
+// stateTr is the state after reading `tr`.
+func stateTr(s *scanner, c byte) int {
+	if c == 'u' {
+		s.step = stateTru
+		return scanContinue
+	}
+	return s.error(c, "in literal true (expecting 'u')")
+}
+
+// stateTru is the state after reading `tru`.
+func stateTru(s *scanner, c byte) int {
+	if c == 'e' {
+		s.step = stateEndValue
+		return scanContinue
+	}
+	return s.error(c, "in literal true (expecting 'e')")
+}
+
+// stateF is the state after reading `f`.
+func stateF(s *scanner, c byte) int {
+	if c == 'a' {
+		s.step = stateFa
+		return scanContinue
+	}
+	return s.error(c, "in literal false (expecting 'a')")
+}
+
+// stateFa is the state after reading `fa`.
+func stateFa(s *scanner, c byte) int {
+	if c == 'l' {
+		s.step = stateFal
+		return scanContinue
+	}
+	return s.error(c, "in literal false (expecting 'l')")
+}
+
+// stateFal is the state after reading `fal`.
+func stateFal(s *scanner, c byte) int {
+	if c == 's' {
+		s.step = stateFals
+		return scanContinue
+	}
+	return s.error(c, "in literal false (expecting 's')")
+}
+
+// stateFals is the state after reading `fals`.
+func stateFals(s *scanner, c byte) int {
+	if c == 'e' {
+		s.step = stateEndValue
+		return scanContinue
+	}
+	return s.error(c, "in literal false (expecting 'e')")
+}
+
+// stateN is the state after reading `n`.
+func stateN(s *scanner, c byte) int {
+	if c == 'u' {
+		s.step = stateNu
+		return scanContinue
+	}
+	return s.error(c, "in literal null (expecting 'u')")
+}
+
+// stateNu is the state after reading `nu`.
+func stateNu(s *scanner, c byte) int {
+	if c == 'l' {
+		s.step = stateNul
+		return scanContinue
+	}
+	return s.error(c, "in literal null (expecting 'l')")
+}
+
+// stateNul is the state after reading `nul`.
+func stateNul(s *scanner, c byte) int {
+	if c == 'l' {
+		s.step = stateEndValue
+		return scanContinue
+	}
+	return s.error(c, "in literal null (expecting 'l')")
+}
+
+// stateError is the state after reaching a syntax error,
+// such as after reading `[1}` or `5.1.2`.
+func stateError(s *scanner, c byte) int {
+	return scanError
+}
+
+// error records an error and switches to the error state.
+func (s *scanner) error(c byte, context string) int {
+	s.step = stateError
+	s.err = &SyntaxError{"invalid character " + quoteChar(c) + " " + context, s.bytes}
+	return scanError
+}
+
+// quoteChar formats c as a quoted character literal
+func quoteChar(c byte) string {
+	// special cases - different from quoted strings
+	if c == '\'' {
+		return `'\''`
+	}
+	if c == '"' {
+		return `'"'`
+	}
+
+	// use quoted string with different quotation marks
+	s := strconv.Quote(string(c))
+	return "'" + s[1:len(s)-1] + "'"
+}
+
+// undo causes the scanner to return scanCode from the next state transition.
+// This gives callers a simple 1-byte undo mechanism.
+func (s *scanner) undo(scanCode int) {
+	if s.redo {
+		panic("json: invalid use of scanner")
+	}
+	s.redoCode = scanCode
+	s.redoState = s.step
+	s.step = stateRedo
+	s.redo = true
+}
+
+// stateRedo helps implement the scanner's 1-byte undo.
+func stateRedo(s *scanner, c byte) int {
+	s.redo = false
+	s.step = s.redoState
+	return s.redoCode
+}

src/vendor/gopkg.in/square/go-jose.v2/json/stream.go

@@ -0,0 +1,480 @@
+// Copyright 2010 The Go Authors.  All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package json
+
+import (
+	"bytes"
+	"errors"
+	"io"
+)
+
+// A Decoder reads and decodes JSON objects from an input stream.
+type Decoder struct {
+	r     io.Reader
+	buf   []byte
+	d     decodeState
+	scanp int // start of unread data in buf
+	scan  scanner
+	err   error
+
+	tokenState int
+	tokenStack []int
+}
+
+// NewDecoder returns a new decoder that reads from r.
+//
+// The decoder introduces its own buffering and may
+// read data from r beyond the JSON values requested.
+func NewDecoder(r io.Reader) *Decoder {
+	return &Decoder{r: r}
+}
+
+// UseNumber causes the Decoder to unmarshal a number into an interface{} as a
+// Number instead of as a float64.
+func (dec *Decoder) UseNumber() { dec.d.useNumber = true }
+
+// Decode reads the next JSON-encoded value from its
+// input and stores it in the value pointed to by v.
+//
+// See the documentation for Unmarshal for details about
+// the conversion of JSON into a Go value.
+func (dec *Decoder) Decode(v interface{}) error {
+	if dec.err != nil {
+		return dec.err
+	}
+
+	if err := dec.tokenPrepareForDecode(); err != nil {
+		return err
+	}
+
+	if !dec.tokenValueAllowed() {
+		return &SyntaxError{msg: "not at beginning of value"}
+	}
+
+	// Read whole value into buffer.
+	n, err := dec.readValue()
+	if err != nil {
+		return err
+	}
+	dec.d.init(dec.buf[dec.scanp : dec.scanp+n])
+	dec.scanp += n
+
+	// Don't save err from unmarshal into dec.err:
+	// the connection is still usable since we read a complete JSON
+	// object from it before the error happened.
+	err = dec.d.unmarshal(v)
+
+	// fixup token streaming state
+	dec.tokenValueEnd()
+
+	return err
+}
+
+// Buffered returns a reader of the data remaining in the Decoder's
+// buffer. The reader is valid until the next call to Decode.
+func (dec *Decoder) Buffered() io.Reader {
+	return bytes.NewReader(dec.buf[dec.scanp:])
+}
+
+// readValue reads a JSON value into dec.buf.
+// It returns the length of the encoding.
+func (dec *Decoder) readValue() (int, error) {
+	dec.scan.reset()
+
+	scanp := dec.scanp
+	var err error
+Input:
+	for {
+		// Look in the buffer for a new value.
+		for i, c := range dec.buf[scanp:] {
+			dec.scan.bytes++
+			v := dec.scan.step(&dec.scan, c)
+			if v == scanEnd {
+				scanp += i
+				break Input
+			}
+			// scanEnd is delayed one byte.
+			// We might block trying to get that byte from src,
+			// so instead invent a space byte.
+			if (v == scanEndObject || v == scanEndArray) && dec.scan.step(&dec.scan, ' ') == scanEnd {
+				scanp += i + 1
+				break Input
+			}
+			if v == scanError {
+				dec.err = dec.scan.err
+				return 0, dec.scan.err
+			}
+		}
+		scanp = len(dec.buf)
+
+		// Did the last read have an error?
+		// Delayed until now to allow buffer scan.
+		if err != nil {
+			if err == io.EOF {
+				if dec.scan.step(&dec.scan, ' ') == scanEnd {
+					break Input
+				}
+				if nonSpace(dec.buf) {
+					err = io.ErrUnexpectedEOF
+				}
+			}
+			dec.err = err
+			return 0, err
+		}
+
+		n := scanp - dec.scanp
+		err = dec.refill()
+		scanp = dec.scanp + n
+	}
+	return scanp - dec.scanp, nil
+}
+
+func (dec *Decoder) refill() error {
+	// Make room to read more into the buffer.
+	// First slide down data already consumed.
+	if dec.scanp > 0 {
+		n := copy(dec.buf, dec.buf[dec.scanp:])
+		dec.buf = dec.buf[:n]
+		dec.scanp = 0
+	}
+
+	// Grow buffer if not large enough.
+	const minRead = 512
+	if cap(dec.buf)-len(dec.buf) < minRead {
+		newBuf := make([]byte, len(dec.buf), 2*cap(dec.buf)+minRead)
+		copy(newBuf, dec.buf)
+		dec.buf = newBuf
+	}
+
+	// Read.  Delay error for next iteration (after scan).
+	n, err := dec.r.Read(dec.buf[len(dec.buf):cap(dec.buf)])
+	dec.buf = dec.buf[0 : len(dec.buf)+n]
+
+	return err
+}
+
+func nonSpace(b []byte) bool {
+	for _, c := range b {
+		if !isSpace(c) {
+			return true
+		}
+	}
+	return false
+}
+
+// An Encoder writes JSON objects to an output stream.
+type Encoder struct {
+	w   io.Writer
+	err error
+}
+
+// NewEncoder returns a new encoder that writes to w.
+func NewEncoder(w io.Writer) *Encoder {
+	return &Encoder{w: w}
+}
+
+// Encode writes the JSON encoding of v to the stream,
+// followed by a newline character.
+//
+// See the documentation for Marshal for details about the
+// conversion of Go values to JSON.
+func (enc *Encoder) Encode(v interface{}) error {
+	if enc.err != nil {
+		return enc.err
+	}
+	e := newEncodeState()
+	err := e.marshal(v)
+	if err != nil {
+		return err
+	}
+
+	// Terminate each value with a newline.
+	// This makes the output look a little nicer
+	// when debugging, and some kind of space
+	// is required if the encoded value was a number,
+	// so that the reader knows there aren't more
+	// digits coming.
+	e.WriteByte('\n')
+
+	if _, err = enc.w.Write(e.Bytes()); err != nil {
+		enc.err = err
+	}
+	encodeStatePool.Put(e)
+	return err
+}
+
+// RawMessage is a raw encoded JSON object.
+// It implements Marshaler and Unmarshaler and can
+// be used to delay JSON decoding or precompute a JSON encoding.
+type RawMessage []byte
+
+// MarshalJSON returns *m as the JSON encoding of m.
+func (m *RawMessage) MarshalJSON() ([]byte, error) {
+	return *m, nil
+}
+
+// UnmarshalJSON sets *m to a copy of data.
+func (m *RawMessage) UnmarshalJSON(data []byte) error {
+	if m == nil {
+		return errors.New("json.RawMessage: UnmarshalJSON on nil pointer")
+	}
+	*m = append((*m)[0:0], data...)
+	return nil
+}
+
+var _ Marshaler = (*RawMessage)(nil)
+var _ Unmarshaler = (*RawMessage)(nil)
+
+// A Token holds a value of one of these types:
+//
+//	Delim, for the four JSON delimiters [ ] { }
+//	bool, for JSON booleans
+//	float64, for JSON numbers
+//	Number, for JSON numbers
+//	string, for JSON string literals
+//	nil, for JSON null
+//
+type Token interface{}
+
+const (
+	tokenTopValue = iota
+	tokenArrayStart
+	tokenArrayValue
+	tokenArrayComma
+	tokenObjectStart
+	tokenObjectKey
+	tokenObjectColon
+	tokenObjectValue
+	tokenObjectComma
+)
+
+// advance tokenstate from a separator state to a value state
+func (dec *Decoder) tokenPrepareForDecode() error {
+	// Note: Not calling peek before switch, to avoid
+	// putting peek into the standard Decode path.
+	// peek is only called when using the Token API.
+	switch dec.tokenState {
+	case tokenArrayComma:
+		c, err := dec.peek()
+		if err != nil {
+			return err
+		}
+		if c != ',' {
+			return &SyntaxError{"expected comma after array element", 0}
+		}
+		dec.scanp++
+		dec.tokenState = tokenArrayValue
+	case tokenObjectColon:
+		c, err := dec.peek()
+		if err != nil {
+			return err
+		}
+		if c != ':' {
+			return &SyntaxError{"expected colon after object key", 0}
+		}
+		dec.scanp++
+		dec.tokenState = tokenObjectValue
+	}
+	return nil
+}
+
+func (dec *Decoder) tokenValueAllowed() bool {
+	switch dec.tokenState {
+	case tokenTopValue, tokenArrayStart, tokenArrayValue, tokenObjectValue:
+		return true
+	}
+	return false
+}
+
+func (dec *Decoder) tokenValueEnd() {
+	switch dec.tokenState {
+	case tokenArrayStart, tokenArrayValue:
+		dec.tokenState = tokenArrayComma
+	case tokenObjectValue:
+		dec.tokenState = tokenObjectComma
+	}
+}
+
+// A Delim is a JSON array or object delimiter, one of [ ] { or }.
+type Delim rune
+
+func (d Delim) String() string {
+	return string(d)
+}
+
+// Token returns the next JSON token in the input stream.
+// At the end of the input stream, Token returns nil, io.EOF.
+//
+// Token guarantees that the delimiters [ ] { } it returns are
+// properly nested and matched: if Token encounters an unexpected
+// delimiter in the input, it will return an error.
+//
+// The input stream consists of basic JSON values—bool, string,
+// number, and null—along with delimiters [ ] { } of type Delim
+// to mark the start and end of arrays and objects.
+// Commas and colons are elided.
+func (dec *Decoder) Token() (Token, error) {
+	for {
+		c, err := dec.peek()
+		if err != nil {
+			return nil, err
+		}
+		switch c {
+		case '[':
+			if !dec.tokenValueAllowed() {
+				return dec.tokenError(c)
+			}
+			dec.scanp++
+			dec.tokenStack = append(dec.tokenStack, dec.tokenState)
+			dec.tokenState = tokenArrayStart
+			return Delim('['), nil
+
+		case ']':
+			if dec.tokenState != tokenArrayStart && dec.tokenState != tokenArrayComma {
+				return dec.tokenError(c)
+			}
+			dec.scanp++
+			dec.tokenState = dec.tokenStack[len(dec.tokenStack)-1]
+			dec.tokenStack = dec.tokenStack[:len(dec.tokenStack)-1]
+			dec.tokenValueEnd()
+			return Delim(']'), nil
+
+		case '{':
+			if !dec.tokenValueAllowed() {
+				return dec.tokenError(c)
+			}
+			dec.scanp++
+			dec.tokenStack = append(dec.tokenStack, dec.tokenState)
+			dec.tokenState = tokenObjectStart
+			return Delim('{'), nil
+
+		case '}':
+			if dec.tokenState != tokenObjectStart && dec.tokenState != tokenObjectComma {
+				return dec.tokenError(c)
+			}
+			dec.scanp++
+			dec.tokenState = dec.tokenStack[len(dec.tokenStack)-1]
+			dec.tokenStack = dec.tokenStack[:len(dec.tokenStack)-1]
+			dec.tokenValueEnd()
+			return Delim('}'), nil
+
+		case ':':
+			if dec.tokenState != tokenObjectColon {
+				return dec.tokenError(c)
+			}
+			dec.scanp++
+			dec.tokenState = tokenObjectValue
+			continue
+
+		case ',':
+			if dec.tokenState == tokenArrayComma {
+				dec.scanp++
+				dec.tokenState = tokenArrayValue
+				continue
+			}
+			if dec.tokenState == tokenObjectComma {
+				dec.scanp++
+				dec.tokenState = tokenObjectKey
+				continue
+			}
+			return dec.tokenError(c)
+
+		case '"':
+			if dec.tokenState == tokenObjectStart || dec.tokenState == tokenObjectKey {
+				var x string
+				old := dec.tokenState
+				dec.tokenState = tokenTopValue
+				err := dec.Decode(&x)
+				dec.tokenState = old
+				if err != nil {
+					clearOffset(err)
+					return nil, err
+				}
+				dec.tokenState = tokenObjectColon
+				return x, nil
+			}
+			fallthrough
+
+		default:
+			if !dec.tokenValueAllowed() {
+				return dec.tokenError(c)
+			}
+			var x interface{}
+			if err := dec.Decode(&x); err != nil {
+				clearOffset(err)
+				return nil, err
+			}
+			return x, nil
+		}
+	}
+}
+
+func clearOffset(err error) {
+	if s, ok := err.(*SyntaxError); ok {
+		s.Offset = 0
+	}
+}
+
+func (dec *Decoder) tokenError(c byte) (Token, error) {
+	var context string
+	switch dec.tokenState {
+	case tokenTopValue:
+		context = " looking for beginning of value"
+	case tokenArrayStart, tokenArrayValue, tokenObjectValue:
+		context = " looking for beginning of value"
+	case tokenArrayComma:
+		context = " after array element"
+	case tokenObjectKey:
+		context = " looking for beginning of object key string"
+	case tokenObjectColon:
+		context = " after object key"
+	case tokenObjectComma:
+		context = " after object key:value pair"
+	}
+	return nil, &SyntaxError{"invalid character " + quoteChar(c) + " " + context, 0}
+}
+
+// More reports whether there is another element in the
+// current array or object being parsed.
+func (dec *Decoder) More() bool {
+	c, err := dec.peek()
+	return err == nil && c != ']' && c != '}'
+}
+
+func (dec *Decoder) peek() (byte, error) {
+	var err error
+	for {
+		for i := dec.scanp; i < len(dec.buf); i++ {
+			c := dec.buf[i]
+			if isSpace(c) {
+				continue
+			}
+			dec.scanp = i
+			return c, nil
+		}
+		// buffer has been scanned, now report any error
+		if err != nil {
+			return 0, err
+		}
+		err = dec.refill()
+	}
+}
+
+/*
+TODO
+
+// EncodeToken writes the given JSON token to the stream.
+// It returns an error if the delimiters [ ] { } are not properly used.
+//
+// EncodeToken does not call Flush, because usually it is part of
+// a larger operation such as Encode, and those will call Flush when finished.
+// Callers that create an Encoder and then invoke EncodeToken directly,
+// without using Encode, need to call Flush when finished to ensure that
+// the JSON is written to the underlying writer.
+func (e *Encoder) EncodeToken(t Token) error  {
+	...
+}
+
+*/

src/vendor/gopkg.in/square/go-jose.v2/json/tags.go

@@ -0,0 +1,44 @@
+// Copyright 2011 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package json
+
+import (
+	"strings"
+)
+
+// tagOptions is the string following a comma in a struct field's "json"
+// tag, or the empty string. It does not include the leading comma.
+type tagOptions string
+
+// parseTag splits a struct field's json tag into its name and
+// comma-separated options.
+func parseTag(tag string) (string, tagOptions) {
+	if idx := strings.Index(tag, ","); idx != -1 {
+		return tag[:idx], tagOptions(tag[idx+1:])
+	}
+	return tag, tagOptions("")
+}
+
+// Contains reports whether a comma-separated list of options
+// contains a particular substr flag. substr must be surrounded by a
+// string boundary or commas.
+func (o tagOptions) Contains(optionName string) bool {
+	if len(o) == 0 {
+		return false
+	}
+	s := string(o)
+	for s != "" {
+		var next string
+		i := strings.Index(s, ",")
+		if i >= 0 {
+			s, next = s[:i], s[i+1:]
+		}
+		if s == optionName {
+			return true
+		}
+		s = next
+	}
+	return false
+}

src/vendor/gopkg.in/square/go-jose.v2/jwe.go

@@ -0,0 +1,294 @@
+/*-
+ * Copyright 2014 Square Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package jose
+
+import (
+	"encoding/base64"
+	"fmt"
+	"strings"
+
+	"gopkg.in/square/go-jose.v2/json"
+)
+
+// rawJSONWebEncryption represents a raw JWE JSON object. Used for parsing/serializing.
+type rawJSONWebEncryption struct {
+	Protected    *byteBuffer        `json:"protected,omitempty"`
+	Unprotected  *rawHeader         `json:"unprotected,omitempty"`
+	Header       *rawHeader         `json:"header,omitempty"`
+	Recipients   []rawRecipientInfo `json:"recipients,omitempty"`
+	Aad          *byteBuffer        `json:"aad,omitempty"`
+	EncryptedKey *byteBuffer        `json:"encrypted_key,omitempty"`
+	Iv           *byteBuffer        `json:"iv,omitempty"`
+	Ciphertext   *byteBuffer        `json:"ciphertext,omitempty"`
+	Tag          *byteBuffer        `json:"tag,omitempty"`
+}
+
+// rawRecipientInfo represents a raw JWE Per-Recipient header JSON object. Used for parsing/serializing.
+type rawRecipientInfo struct {
+	Header       *rawHeader `json:"header,omitempty"`
+	EncryptedKey string     `json:"encrypted_key,omitempty"`
+}
+
+// JSONWebEncryption represents an encrypted JWE object after parsing.
+type JSONWebEncryption struct {
+	Header                   Header
+	protected, unprotected   *rawHeader
+	recipients               []recipientInfo
+	aad, iv, ciphertext, tag []byte
+	original                 *rawJSONWebEncryption
+}
+
+// recipientInfo represents a raw JWE Per-Recipient header JSON object after parsing.
+type recipientInfo struct {
+	header       *rawHeader
+	encryptedKey []byte
+}
+
+// GetAuthData retrieves the (optional) authenticated data attached to the object.
+func (obj JSONWebEncryption) GetAuthData() []byte {
+	if obj.aad != nil {
+		out := make([]byte, len(obj.aad))
+		copy(out, obj.aad)
+		return out
+	}
+
+	return nil
+}
+
+// Get the merged header values
+func (obj JSONWebEncryption) mergedHeaders(recipient *recipientInfo) rawHeader {
+	out := rawHeader{}
+	out.merge(obj.protected)
+	out.merge(obj.unprotected)
+
+	if recipient != nil {
+		out.merge(recipient.header)
+	}
+
+	return out
+}
+
+// Get the additional authenticated data from a JWE object.
+func (obj JSONWebEncryption) computeAuthData() []byte {
+	var protected string
+
+	if obj.original != nil && obj.original.Protected != nil {
+		protected = obj.original.Protected.base64()
+	} else if obj.protected != nil {
+		protected = base64.RawURLEncoding.EncodeToString(mustSerializeJSON((obj.protected)))
+	} else {
+		protected = ""
+	}
+
+	output := []byte(protected)
+	if obj.aad != nil {
+		output = append(output, '.')
+		output = append(output, []byte(base64.RawURLEncoding.EncodeToString(obj.aad))...)
+	}
+
+	return output
+}
+
+// ParseEncrypted parses an encrypted message in compact or full serialization format.
+func ParseEncrypted(input string) (*JSONWebEncryption, error) {
+	input = stripWhitespace(input)
+	if strings.HasPrefix(input, "{") {
+		return parseEncryptedFull(input)
+	}
+
+	return parseEncryptedCompact(input)
+}
+
+// parseEncryptedFull parses a message in compact format.
+func parseEncryptedFull(input string) (*JSONWebEncryption, error) {
+	var parsed rawJSONWebEncryption
+	err := json.Unmarshal([]byte(input), &parsed)
+	if err != nil {
+		return nil, err
+	}
+
+	return parsed.sanitized()
+}
+
+// sanitized produces a cleaned-up JWE object from the raw JSON.
+func (parsed *rawJSONWebEncryption) sanitized() (*JSONWebEncryption, error) {
+	obj := &JSONWebEncryption{
+		original:    parsed,
+		unprotected: parsed.Unprotected,
+	}
+
+	// Check that there is not a nonce in the unprotected headers
+	if parsed.Unprotected != nil {
+		if nonce := parsed.Unprotected.getNonce(); nonce != "" {
+			return nil, ErrUnprotectedNonce
+		}
+	}
+	if parsed.Header != nil {
+		if nonce := parsed.Header.getNonce(); nonce != "" {
+			return nil, ErrUnprotectedNonce
+		}
+	}
+
+	if parsed.Protected != nil && len(parsed.Protected.bytes()) > 0 {
+		err := json.Unmarshal(parsed.Protected.bytes(), &obj.protected)
+		if err != nil {
+			return nil, fmt.Errorf("square/go-jose: invalid protected header: %s, %s", err, parsed.Protected.base64())
+		}
+	}
+
+	// Note: this must be called _after_ we parse the protected header,
+	// otherwise fields from the protected header will not get picked up.
+	var err error
+	mergedHeaders := obj.mergedHeaders(nil)
+	obj.Header, err = mergedHeaders.sanitized()
+	if err != nil {
+		return nil, fmt.Errorf("square/go-jose: cannot sanitize merged headers: %v (%v)", err, mergedHeaders)
+	}
+
+	if len(parsed.Recipients) == 0 {
+		obj.recipients = []recipientInfo{
+			{
+				header:       parsed.Header,
+				encryptedKey: parsed.EncryptedKey.bytes(),
+			},
+		}
+	} else {
+		obj.recipients = make([]recipientInfo, len(parsed.Recipients))
+		for r := range parsed.Recipients {
+			encryptedKey, err := base64.RawURLEncoding.DecodeString(parsed.Recipients[r].EncryptedKey)
+			if err != nil {
+				return nil, err
+			}
+
+			// Check that there is not a nonce in the unprotected header
+			if parsed.Recipients[r].Header != nil && parsed.Recipients[r].Header.getNonce() != "" {
+				return nil, ErrUnprotectedNonce
+			}
+
+			obj.recipients[r].header = parsed.Recipients[r].Header
+			obj.recipients[r].encryptedKey = encryptedKey
+		}
+	}
+
+	for _, recipient := range obj.recipients {
+		headers := obj.mergedHeaders(&recipient)
+		if headers.getAlgorithm() == "" || headers.getEncryption() == "" {
+			return nil, fmt.Errorf("square/go-jose: message is missing alg/enc headers")
+		}
+	}
+
+	obj.iv = parsed.Iv.bytes()
+	obj.ciphertext = parsed.Ciphertext.bytes()
+	obj.tag = parsed.Tag.bytes()
+	obj.aad = parsed.Aad.bytes()
+
+	return obj, nil
+}
+
+// parseEncryptedCompact parses a message in compact format.
+func parseEncryptedCompact(input string) (*JSONWebEncryption, error) {
+	parts := strings.Split(input, ".")
+	if len(parts) != 5 {
+		return nil, fmt.Errorf("square/go-jose: compact JWE format must have five parts")
+	}
+
+	rawProtected, err := base64.RawURLEncoding.DecodeString(parts[0])
+	if err != nil {
+		return nil, err
+	}
+
+	encryptedKey, err := base64.RawURLEncoding.DecodeString(parts[1])
+	if err != nil {
+		return nil, err
+	}
+
+	iv, err := base64.RawURLEncoding.DecodeString(parts[2])
+	if err != nil {
+		return nil, err
+	}
+
+	ciphertext, err := base64.RawURLEncoding.DecodeString(parts[3])
+	if err != nil {
+		return nil, err
+	}
+
+	tag, err := base64.RawURLEncoding.DecodeString(parts[4])
+	if err != nil {
+		return nil, err
+	}
+
+	raw := &rawJSONWebEncryption{
+		Protected:    newBuffer(rawProtected),
+		EncryptedKey: newBuffer(encryptedKey),
+		Iv:           newBuffer(iv),
+		Ciphertext:   newBuffer(ciphertext),
+		Tag:          newBuffer(tag),
+	}
+
+	return raw.sanitized()
+}
+
+// CompactSerialize serializes an object using the compact serialization format.
+func (obj JSONWebEncryption) CompactSerialize() (string, error) {
+	if len(obj.recipients) != 1 || obj.unprotected != nil ||
+		obj.protected == nil || obj.recipients[0].header != nil {
+		return "", ErrNotSupported
+	}
+
+	serializedProtected := mustSerializeJSON(obj.protected)
+
+	return fmt.Sprintf(
+		"%s.%s.%s.%s.%s",
+		base64.RawURLEncoding.EncodeToString(serializedProtected),
+		base64.RawURLEncoding.EncodeToString(obj.recipients[0].encryptedKey),
+		base64.RawURLEncoding.EncodeToString(obj.iv),
+		base64.RawURLEncoding.EncodeToString(obj.ciphertext),
+		base64.RawURLEncoding.EncodeToString(obj.tag)), nil
+}
+
+// FullSerialize serializes an object using the full JSON serialization format.
+func (obj JSONWebEncryption) FullSerialize() string {
+	raw := rawJSONWebEncryption{
+		Unprotected:  obj.unprotected,
+		Iv:           newBuffer(obj.iv),
+		Ciphertext:   newBuffer(obj.ciphertext),
+		EncryptedKey: newBuffer(obj.recipients[0].encryptedKey),
+		Tag:          newBuffer(obj.tag),
+		Aad:          newBuffer(obj.aad),
+		Recipients:   []rawRecipientInfo{},
+	}
+
+	if len(obj.recipients) > 1 {
+		for _, recipient := range obj.recipients {
+			info := rawRecipientInfo{
+				Header:       recipient.header,
+				EncryptedKey: base64.RawURLEncoding.EncodeToString(recipient.encryptedKey),
+			}
+			raw.Recipients = append(raw.Recipients, info)
+		}
+	} else {
+		// Use flattened serialization
+		raw.Header = obj.recipients[0].header
+		raw.EncryptedKey = newBuffer(obj.recipients[0].encryptedKey)
+	}
+
+	if obj.protected != nil {
+		raw.Protected = newBuffer(mustSerializeJSON(obj.protected))
+	}
+
+	return string(mustSerializeJSON(raw))
+}

src/vendor/gopkg.in/square/go-jose.v2/jwk.go

@@ -0,0 +1,608 @@
+/*-
+ * Copyright 2014 Square Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package jose
+
+import (
+	"crypto"
+	"crypto/ecdsa"
+	"crypto/elliptic"
+	"crypto/rsa"
+	"crypto/x509"
+	"encoding/base64"
+	"errors"
+	"fmt"
+	"math/big"
+	"reflect"
+	"strings"
+
+	"golang.org/x/crypto/ed25519"
+
+	"gopkg.in/square/go-jose.v2/json"
+)
+
+// rawJSONWebKey represents a public or private key in JWK format, used for parsing/serializing.
+type rawJSONWebKey struct {
+	Use string      `json:"use,omitempty"`
+	Kty string      `json:"kty,omitempty"`
+	Kid string      `json:"kid,omitempty"`
+	Crv string      `json:"crv,omitempty"`
+	Alg string      `json:"alg,omitempty"`
+	K   *byteBuffer `json:"k,omitempty"`
+	X   *byteBuffer `json:"x,omitempty"`
+	Y   *byteBuffer `json:"y,omitempty"`
+	N   *byteBuffer `json:"n,omitempty"`
+	E   *byteBuffer `json:"e,omitempty"`
+	// -- Following fields are only used for private keys --
+	// RSA uses D, P and Q, while ECDSA uses only D. Fields Dp, Dq, and Qi are
+	// completely optional. Therefore for RSA/ECDSA, D != nil is a contract that
+	// we have a private key whereas D == nil means we have only a public key.
+	D  *byteBuffer `json:"d,omitempty"`
+	P  *byteBuffer `json:"p,omitempty"`
+	Q  *byteBuffer `json:"q,omitempty"`
+	Dp *byteBuffer `json:"dp,omitempty"`
+	Dq *byteBuffer `json:"dq,omitempty"`
+	Qi *byteBuffer `json:"qi,omitempty"`
+	// Certificates
+	X5c []string `json:"x5c,omitempty"`
+}
+
+// JSONWebKey represents a public or private key in JWK format.
+type JSONWebKey struct {
+	Key          interface{}
+	Certificates []*x509.Certificate
+	KeyID        string
+	Algorithm    string
+	Use          string
+}
+
+// MarshalJSON serializes the given key to its JSON representation.
+func (k JSONWebKey) MarshalJSON() ([]byte, error) {
+	var raw *rawJSONWebKey
+	var err error
+
+	switch key := k.Key.(type) {
+	case ed25519.PublicKey:
+		raw = fromEdPublicKey(key)
+	case *ecdsa.PublicKey:
+		raw, err = fromEcPublicKey(key)
+	case *rsa.PublicKey:
+		raw = fromRsaPublicKey(key)
+	case ed25519.PrivateKey:
+		raw, err = fromEdPrivateKey(key)
+	case *ecdsa.PrivateKey:
+		raw, err = fromEcPrivateKey(key)
+	case *rsa.PrivateKey:
+		raw, err = fromRsaPrivateKey(key)
+	case []byte:
+		raw, err = fromSymmetricKey(key)
+	default:
+		return nil, fmt.Errorf("square/go-jose: unknown key type '%s'", reflect.TypeOf(key))
+	}
+
+	if err != nil {
+		return nil, err
+	}
+
+	raw.Kid = k.KeyID
+	raw.Alg = k.Algorithm
+	raw.Use = k.Use
+
+	for _, cert := range k.Certificates {
+		raw.X5c = append(raw.X5c, base64.StdEncoding.EncodeToString(cert.Raw))
+	}
+
+	return json.Marshal(raw)
+}
+
+// UnmarshalJSON reads a key from its JSON representation.
+func (k *JSONWebKey) UnmarshalJSON(data []byte) (err error) {
+	var raw rawJSONWebKey
+	err = json.Unmarshal(data, &raw)
+	if err != nil {
+		return err
+	}
+
+	var key interface{}
+	switch raw.Kty {
+	case "EC":
+		if raw.D != nil {
+			key, err = raw.ecPrivateKey()
+		} else {
+			key, err = raw.ecPublicKey()
+		}
+	case "RSA":
+		if raw.D != nil {
+			key, err = raw.rsaPrivateKey()
+		} else {
+			key, err = raw.rsaPublicKey()
+		}
+	case "oct":
+		key, err = raw.symmetricKey()
+	case "OKP":
+		if raw.Crv == "Ed25519" && raw.X != nil {
+			if raw.D != nil {
+				key, err = raw.edPrivateKey()
+			} else {
+				key, err = raw.edPublicKey()
+			}
+		} else {
+			err = fmt.Errorf("square/go-jose: unknown curve %s'", raw.Crv)
+		}
+	default:
+		err = fmt.Errorf("square/go-jose: unknown json web key type '%s'", raw.Kty)
+	}
+
+	if err == nil {
+		*k = JSONWebKey{Key: key, KeyID: raw.Kid, Algorithm: raw.Alg, Use: raw.Use}
+
+		k.Certificates, err = parseCertificateChain(raw.X5c)
+		if err != nil {
+			return fmt.Errorf("failed to unmarshal x5c field: %s", err)
+		}
+	}
+
+	return
+}
+
+// JSONWebKeySet represents a JWK Set object.
+type JSONWebKeySet struct {
+	Keys []JSONWebKey `json:"keys"`
+}
+
+// Key convenience method returns keys by key ID. Specification states
+// that a JWK Set "SHOULD" use distinct key IDs, but allows for some
+// cases where they are not distinct. Hence method returns a slice
+// of JSONWebKeys.
+func (s *JSONWebKeySet) Key(kid string) []JSONWebKey {
+	var keys []JSONWebKey
+	for _, key := range s.Keys {
+		if key.KeyID == kid {
+			keys = append(keys, key)
+		}
+	}
+
+	return keys
+}
+
+const rsaThumbprintTemplate = `{"e":"%s","kty":"RSA","n":"%s"}`
+const ecThumbprintTemplate = `{"crv":"%s","kty":"EC","x":"%s","y":"%s"}`
+const edThumbprintTemplate = `{"crv":"%s","kty":"OKP",x":"%s"}`
+
+func ecThumbprintInput(curve elliptic.Curve, x, y *big.Int) (string, error) {
+	coordLength := curveSize(curve)
+	crv, err := curveName(curve)
+	if err != nil {
+		return "", err
+	}
+
+	if len(x.Bytes()) > coordLength || len(y.Bytes()) > coordLength {
+		return "", errors.New("square/go-jose: invalid elliptic key (too large)")
+	}
+
+	return fmt.Sprintf(ecThumbprintTemplate, crv,
+		newFixedSizeBuffer(x.Bytes(), coordLength).base64(),
+		newFixedSizeBuffer(y.Bytes(), coordLength).base64()), nil
+}
+
+func rsaThumbprintInput(n *big.Int, e int) (string, error) {
+	return fmt.Sprintf(rsaThumbprintTemplate,
+		newBufferFromInt(uint64(e)).base64(),
+		newBuffer(n.Bytes()).base64()), nil
+}
+
+func edThumbprintInput(ed ed25519.PublicKey) (string, error) {
+	crv := "Ed25519"
+	if len(ed) > 32 {
+		return "", errors.New("square/go-jose: invalid elliptic key (too large)")
+	}
+	return fmt.Sprintf(edThumbprintTemplate, crv,
+		newFixedSizeBuffer(ed, 32).base64()), nil
+}
+
+// Thumbprint computes the JWK Thumbprint of a key using the
+// indicated hash algorithm.
+func (k *JSONWebKey) Thumbprint(hash crypto.Hash) ([]byte, error) {
+	var input string
+	var err error
+	switch key := k.Key.(type) {
+	case ed25519.PublicKey:
+		input, err = edThumbprintInput(key)
+	case *ecdsa.PublicKey:
+		input, err = ecThumbprintInput(key.Curve, key.X, key.Y)
+	case *ecdsa.PrivateKey:
+		input, err = ecThumbprintInput(key.Curve, key.X, key.Y)
+	case *rsa.PublicKey:
+		input, err = rsaThumbprintInput(key.N, key.E)
+	case *rsa.PrivateKey:
+		input, err = rsaThumbprintInput(key.N, key.E)
+	case ed25519.PrivateKey:
+		input, err = edThumbprintInput(ed25519.PublicKey(key[0:32]))
+	default:
+		return nil, fmt.Errorf("square/go-jose: unknown key type '%s'", reflect.TypeOf(key))
+	}
+
+	if err != nil {
+		return nil, err
+	}
+
+	h := hash.New()
+	h.Write([]byte(input))
+	return h.Sum(nil), nil
+}
+
+// IsPublic returns true if the JWK represents a public key (not symmetric, not private).
+func (k *JSONWebKey) IsPublic() bool {
+	switch k.Key.(type) {
+	case *ecdsa.PublicKey, *rsa.PublicKey, ed25519.PublicKey:
+		return true
+	default:
+		return false
+	}
+}
+
+// Public creates JSONWebKey with corresponding publik key if JWK represents asymmetric private key.
+func (k *JSONWebKey) Public() JSONWebKey {
+	if k.IsPublic() {
+		return *k
+	}
+	ret := *k
+	switch key := k.Key.(type) {
+	case *ecdsa.PrivateKey:
+		ret.Key = key.Public()
+	case *rsa.PrivateKey:
+		ret.Key = key.Public()
+	case ed25519.PrivateKey:
+		ret.Key = key.Public()
+	default:
+		return JSONWebKey{} // returning invalid key
+	}
+	return ret
+}
+
+// Valid checks that the key contains the expected parameters.
+func (k *JSONWebKey) Valid() bool {
+	if k.Key == nil {
+		return false
+	}
+	switch key := k.Key.(type) {
+	case *ecdsa.PublicKey:
+		if key.Curve == nil || key.X == nil || key.Y == nil {
+			return false
+		}
+	case *ecdsa.PrivateKey:
+		if key.Curve == nil || key.X == nil || key.Y == nil || key.D == nil {
+			return false
+		}
+	case *rsa.PublicKey:
+		if key.N == nil || key.E == 0 {
+			return false
+		}
+	case *rsa.PrivateKey:
+		if key.N == nil || key.E == 0 || key.D == nil || len(key.Primes) < 2 {
+			return false
+		}
+	case ed25519.PublicKey:
+		if len(key) != 32 {
+			return false
+		}
+	case ed25519.PrivateKey:
+		if len(key) != 64 {
+			return false
+		}
+	default:
+		return false
+	}
+	return true
+}
+
+func (key rawJSONWebKey) rsaPublicKey() (*rsa.PublicKey, error) {
+	if key.N == nil || key.E == nil {
+		return nil, fmt.Errorf("square/go-jose: invalid RSA key, missing n/e values")
+	}
+
+	return &rsa.PublicKey{
+		N: key.N.bigInt(),
+		E: key.E.toInt(),
+	}, nil
+}
+
+func fromEdPublicKey(pub ed25519.PublicKey) *rawJSONWebKey {
+	return &rawJSONWebKey{
+		Kty: "OKP",
+		Crv: "Ed25519",
+		X:   newBuffer(pub),
+	}
+}
+
+func fromRsaPublicKey(pub *rsa.PublicKey) *rawJSONWebKey {
+	return &rawJSONWebKey{
+		Kty: "RSA",
+		N:   newBuffer(pub.N.Bytes()),
+		E:   newBufferFromInt(uint64(pub.E)),
+	}
+}
+
+func (key rawJSONWebKey) ecPublicKey() (*ecdsa.PublicKey, error) {
+	var curve elliptic.Curve
+	switch key.Crv {
+	case "P-256":
+		curve = elliptic.P256()
+	case "P-384":
+		curve = elliptic.P384()
+	case "P-521":
+		curve = elliptic.P521()
+	default:
+		return nil, fmt.Errorf("square/go-jose: unsupported elliptic curve '%s'", key.Crv)
+	}
+
+	if key.X == nil || key.Y == nil {
+		return nil, errors.New("square/go-jose: invalid EC key, missing x/y values")
+	}
+
+	// The length of this octet string MUST be the full size of a coordinate for
+	// the curve specified in the "crv" parameter.
+	// https://tools.ietf.org/html/rfc7518#section-6.2.1.2
+	if curveSize(curve) != len(key.X.data) {
+		return nil, fmt.Errorf("square/go-jose: invalid EC private key, wrong length for x")
+	}
+
+	if curveSize(curve) != len(key.Y.data) {
+		return nil, fmt.Errorf("square/go-jose: invalid EC private key, wrong length for y")
+	}
+
+	x := key.X.bigInt()
+	y := key.Y.bigInt()
+
+	if !curve.IsOnCurve(x, y) {
+		return nil, errors.New("square/go-jose: invalid EC key, X/Y are not on declared curve")
+	}
+
+	return &ecdsa.PublicKey{
+		Curve: curve,
+		X:     x,
+		Y:     y,
+	}, nil
+}
+
+func fromEcPublicKey(pub *ecdsa.PublicKey) (*rawJSONWebKey, error) {
+	if pub == nil || pub.X == nil || pub.Y == nil {
+		return nil, fmt.Errorf("square/go-jose: invalid EC key (nil, or X/Y missing)")
+	}
+
+	name, err := curveName(pub.Curve)
+	if err != nil {
+		return nil, err
+	}
+
+	size := curveSize(pub.Curve)
+
+	xBytes := pub.X.Bytes()
+	yBytes := pub.Y.Bytes()
+
+	if len(xBytes) > size || len(yBytes) > size {
+		return nil, fmt.Errorf("square/go-jose: invalid EC key (X/Y too large)")
+	}
+
+	key := &rawJSONWebKey{
+		Kty: "EC",
+		Crv: name,
+		X:   newFixedSizeBuffer(xBytes, size),
+		Y:   newFixedSizeBuffer(yBytes, size),
+	}
+
+	return key, nil
+}
+
+func (key rawJSONWebKey) edPrivateKey() (ed25519.PrivateKey, error) {
+	var missing []string
+	switch {
+	case key.D == nil:
+		missing = append(missing, "D")
+	case key.X == nil:
+		missing = append(missing, "X")
+	}
+
+	if len(missing) > 0 {
+		return nil, fmt.Errorf("square/go-jose: invalid Ed25519 private key, missing %s value(s)", strings.Join(missing, ", "))
+	}
+
+	privateKey := make([]byte, ed25519.PrivateKeySize)
+	copy(privateKey[0:32], key.X.bytes())
+	copy(privateKey[32:], key.D.bytes())
+	rv := ed25519.PrivateKey(privateKey)
+	return rv, nil
+}
+
+func (key rawJSONWebKey) edPublicKey() (ed25519.PublicKey, error) {
+	if key.X == nil {
+		return nil, fmt.Errorf("square/go-jose: invalid Ed key, missing x value")
+	}
+	publicKey := make([]byte, ed25519.PublicKeySize)
+	copy(publicKey[0:32], key.X.bytes())
+	rv := ed25519.PublicKey(publicKey)
+	return rv, nil
+}
+
+func (key rawJSONWebKey) rsaPrivateKey() (*rsa.PrivateKey, error) {
+	var missing []string
+	switch {
+	case key.N == nil:
+		missing = append(missing, "N")
+	case key.E == nil:
+		missing = append(missing, "E")
+	case key.D == nil:
+		missing = append(missing, "D")
+	case key.P == nil:
+		missing = append(missing, "P")
+	case key.Q == nil:
+		missing = append(missing, "Q")
+	}
+
+	if len(missing) > 0 {
+		return nil, fmt.Errorf("square/go-jose: invalid RSA private key, missing %s value(s)", strings.Join(missing, ", "))
+	}
+
+	rv := &rsa.PrivateKey{
+		PublicKey: rsa.PublicKey{
+			N: key.N.bigInt(),
+			E: key.E.toInt(),
+		},
+		D: key.D.bigInt(),
+		Primes: []*big.Int{
+			key.P.bigInt(),
+			key.Q.bigInt(),
+		},
+	}
+
+	if key.Dp != nil {
+		rv.Precomputed.Dp = key.Dp.bigInt()
+	}
+	if key.Dq != nil {
+		rv.Precomputed.Dq = key.Dq.bigInt()
+	}
+	if key.Qi != nil {
+		rv.Precomputed.Qinv = key.Qi.bigInt()
+	}
+
+	err := rv.Validate()
+	return rv, err
+}
+
+func fromEdPrivateKey(ed ed25519.PrivateKey) (*rawJSONWebKey, error) {
+	raw := fromEdPublicKey(ed25519.PublicKey(ed[0:32]))
+
+	raw.D = newBuffer(ed[32:])
+	return raw, nil
+}
+
+func fromRsaPrivateKey(rsa *rsa.PrivateKey) (*rawJSONWebKey, error) {
+	if len(rsa.Primes) != 2 {
+		return nil, ErrUnsupportedKeyType
+	}
+
+	raw := fromRsaPublicKey(&rsa.PublicKey)
+
+	raw.D = newBuffer(rsa.D.Bytes())
+	raw.P = newBuffer(rsa.Primes[0].Bytes())
+	raw.Q = newBuffer(rsa.Primes[1].Bytes())
+
+	if rsa.Precomputed.Dp != nil {
+		raw.Dp = newBuffer(rsa.Precomputed.Dp.Bytes())
+	}
+	if rsa.Precomputed.Dq != nil {
+		raw.Dq = newBuffer(rsa.Precomputed.Dq.Bytes())
+	}
+	if rsa.Precomputed.Qinv != nil {
+		raw.Qi = newBuffer(rsa.Precomputed.Qinv.Bytes())
+	}
+
+	return raw, nil
+}
+
+func (key rawJSONWebKey) ecPrivateKey() (*ecdsa.PrivateKey, error) {
+	var curve elliptic.Curve
+	switch key.Crv {
+	case "P-256":
+		curve = elliptic.P256()
+	case "P-384":
+		curve = elliptic.P384()
+	case "P-521":
+		curve = elliptic.P521()
+	default:
+		return nil, fmt.Errorf("square/go-jose: unsupported elliptic curve '%s'", key.Crv)
+	}
+
+	if key.X == nil || key.Y == nil || key.D == nil {
+		return nil, fmt.Errorf("square/go-jose: invalid EC private key, missing x/y/d values")
+	}
+
+	// The length of this octet string MUST be the full size of a coordinate for
+	// the curve specified in the "crv" parameter.
+	// https://tools.ietf.org/html/rfc7518#section-6.2.1.2
+	if curveSize(curve) != len(key.X.data) {
+		return nil, fmt.Errorf("square/go-jose: invalid EC private key, wrong length for x")
+	}
+
+	if curveSize(curve) != len(key.Y.data) {
+		return nil, fmt.Errorf("square/go-jose: invalid EC private key, wrong length for y")
+	}
+
+	// https://tools.ietf.org/html/rfc7518#section-6.2.2.1
+	if dSize(curve) != len(key.D.data) {
+		return nil, fmt.Errorf("square/go-jose: invalid EC private key, wrong length for d")
+	}
+
+	x := key.X.bigInt()
+	y := key.Y.bigInt()
+
+	if !curve.IsOnCurve(x, y) {
+		return nil, errors.New("square/go-jose: invalid EC key, X/Y are not on declared curve")
+	}
+
+	return &ecdsa.PrivateKey{
+		PublicKey: ecdsa.PublicKey{
+			Curve: curve,
+			X:     x,
+			Y:     y,
+		},
+		D: key.D.bigInt(),
+	}, nil
+}
+
+func fromEcPrivateKey(ec *ecdsa.PrivateKey) (*rawJSONWebKey, error) {
+	raw, err := fromEcPublicKey(&ec.PublicKey)
+	if err != nil {
+		return nil, err
+	}
+
+	if ec.D == nil {
+		return nil, fmt.Errorf("square/go-jose: invalid EC private key")
+	}
+
+	raw.D = newFixedSizeBuffer(ec.D.Bytes(), dSize(ec.PublicKey.Curve))
+
+	return raw, nil
+}
+
+// dSize returns the size in octets for the "d" member of an elliptic curve
+// private key.
+// The length of this octet string MUST be ceiling(log-base-2(n)/8)
+// octets (where n is the order of the curve).
+// https://tools.ietf.org/html/rfc7518#section-6.2.2.1
+func dSize(curve elliptic.Curve) int {
+	order := curve.Params().P
+	bitLen := order.BitLen()
+	size := bitLen / 8
+	if bitLen%8 != 0 {
+		size = size + 1
+	}
+	return size
+}
+
+func fromSymmetricKey(key []byte) (*rawJSONWebKey, error) {
+	return &rawJSONWebKey{
+		Kty: "oct",
+		K:   newBuffer(key),
+	}, nil
+}
+
+func (key rawJSONWebKey) symmetricKey() ([]byte, error) {
+	if key.K == nil {
+		return nil, fmt.Errorf("square/go-jose: invalid OCT (symmetric) key, missing k value")
+	}
+	return key.K.bytes(), nil
+}

src/vendor/gopkg.in/square/go-jose.v2/jws.go

@@ -0,0 +1,321 @@
+/*-
+ * Copyright 2014 Square Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package jose
+
+import (
+	"encoding/base64"
+	"errors"
+	"fmt"
+	"strings"
+
+	"gopkg.in/square/go-jose.v2/json"
+)
+
+// rawJSONWebSignature represents a raw JWS JSON object. Used for parsing/serializing.
+type rawJSONWebSignature struct {
+	Payload    *byteBuffer        `json:"payload,omitempty"`
+	Signatures []rawSignatureInfo `json:"signatures,omitempty"`
+	Protected  *byteBuffer        `json:"protected,omitempty"`
+	Header     *rawHeader         `json:"header,omitempty"`
+	Signature  *byteBuffer        `json:"signature,omitempty"`
+}
+
+// rawSignatureInfo represents a single JWS signature over the JWS payload and protected header.
+type rawSignatureInfo struct {
+	Protected *byteBuffer `json:"protected,omitempty"`
+	Header    *rawHeader  `json:"header,omitempty"`
+	Signature *byteBuffer `json:"signature,omitempty"`
+}
+
+// JSONWebSignature represents a signed JWS object after parsing.
+type JSONWebSignature struct {
+	payload []byte
+	// Signatures attached to this object (may be more than one for multi-sig).
+	// Be careful about accessing these directly, prefer to use Verify() or
+	// VerifyMulti() to ensure that the data you're getting is verified.
+	Signatures []Signature
+}
+
+// Signature represents a single signature over the JWS payload and protected header.
+type Signature struct {
+	// Merged header fields. Contains both protected and unprotected header
+	// values. Prefer using Protected and Unprotected fields instead of this.
+	// Values in this header may or may not have been signed and in general
+	// should not be trusted.
+	Header Header
+
+	// Protected header. Values in this header were signed and
+	// will be verified as part of the signature verification process.
+	Protected Header
+
+	// Unprotected header. Values in this header were not signed
+	// and in general should not be trusted.
+	Unprotected Header
+
+	// The actual signature value
+	Signature []byte
+
+	protected *rawHeader
+	header    *rawHeader
+	original  *rawSignatureInfo
+}
+
+// ParseSigned parses a signed message in compact or full serialization format.
+func ParseSigned(input string) (*JSONWebSignature, error) {
+	input = stripWhitespace(input)
+	if strings.HasPrefix(input, "{") {
+		return parseSignedFull(input)
+	}
+
+	return parseSignedCompact(input)
+}
+
+// Get a header value
+func (sig Signature) mergedHeaders() rawHeader {
+	out := rawHeader{}
+	out.merge(sig.protected)
+	out.merge(sig.header)
+	return out
+}
+
+// Compute data to be signed
+func (obj JSONWebSignature) computeAuthData(payload []byte, signature *Signature) []byte {
+	var serializedProtected string
+
+	if signature.original != nil && signature.original.Protected != nil {
+		serializedProtected = signature.original.Protected.base64()
+	} else if signature.protected != nil {
+		serializedProtected = base64.RawURLEncoding.EncodeToString(mustSerializeJSON(signature.protected))
+	} else {
+		serializedProtected = ""
+	}
+
+	return []byte(fmt.Sprintf("%s.%s",
+		serializedProtected,
+		base64.RawURLEncoding.EncodeToString(payload)))
+}
+
+// parseSignedFull parses a message in full format.
+func parseSignedFull(input string) (*JSONWebSignature, error) {
+	var parsed rawJSONWebSignature
+	err := json.Unmarshal([]byte(input), &parsed)
+	if err != nil {
+		return nil, err
+	}
+
+	return parsed.sanitized()
+}
+
+// sanitized produces a cleaned-up JWS object from the raw JSON.
+func (parsed *rawJSONWebSignature) sanitized() (*JSONWebSignature, error) {
+	if parsed.Payload == nil {
+		return nil, fmt.Errorf("square/go-jose: missing payload in JWS message")
+	}
+
+	obj := &JSONWebSignature{
+		payload:    parsed.Payload.bytes(),
+		Signatures: make([]Signature, len(parsed.Signatures)),
+	}
+
+	if len(parsed.Signatures) == 0 {
+		// No signatures array, must be flattened serialization
+		signature := Signature{}
+		if parsed.Protected != nil && len(parsed.Protected.bytes()) > 0 {
+			signature.protected = &rawHeader{}
+			err := json.Unmarshal(parsed.Protected.bytes(), signature.protected)
+			if err != nil {
+				return nil, err
+			}
+		}
+
+		// Check that there is not a nonce in the unprotected header
+		if parsed.Header != nil && parsed.Header.getNonce() != "" {
+			return nil, ErrUnprotectedNonce
+		}
+
+		signature.header = parsed.Header
+		signature.Signature = parsed.Signature.bytes()
+		// Make a fake "original" rawSignatureInfo to store the unprocessed
+		// Protected header. This is necessary because the Protected header can
+		// contain arbitrary fields not registered as part of the spec. See
+		// https://tools.ietf.org/html/draft-ietf-jose-json-web-signature-41#section-4
+		// If we unmarshal Protected into a rawHeader with its explicit list of fields,
+		// we cannot marshal losslessly. So we have to keep around the original bytes.
+		// This is used in computeAuthData, which will first attempt to use
+		// the original bytes of a protected header, and fall back on marshaling the
+		// header struct only if those bytes are not available.
+		signature.original = &rawSignatureInfo{
+			Protected: parsed.Protected,
+			Header:    parsed.Header,
+			Signature: parsed.Signature,
+		}
+
+		var err error
+		signature.Header, err = signature.mergedHeaders().sanitized()
+		if err != nil {
+			return nil, err
+		}
+
+		if signature.header != nil {
+			signature.Unprotected, err = signature.header.sanitized()
+			if err != nil {
+				return nil, err
+			}
+		}
+
+		if signature.protected != nil {
+			signature.Protected, err = signature.protected.sanitized()
+			if err != nil {
+				return nil, err
+			}
+		}
+
+		// As per RFC 7515 Section 4.1.3, only public keys are allowed to be embedded.
+		jwk := signature.Header.JSONWebKey
+		if jwk != nil && (!jwk.Valid() || !jwk.IsPublic()) {
+			return nil, errors.New("square/go-jose: invalid embedded jwk, must be public key")
+		}
+
+		obj.Signatures = append(obj.Signatures, signature)
+	}
+
+	for i, sig := range parsed.Signatures {
+		if sig.Protected != nil && len(sig.Protected.bytes()) > 0 {
+			obj.Signatures[i].protected = &rawHeader{}
+			err := json.Unmarshal(sig.Protected.bytes(), obj.Signatures[i].protected)
+			if err != nil {
+				return nil, err
+			}
+		}
+
+		// Check that there is not a nonce in the unprotected header
+		if sig.Header != nil && sig.Header.getNonce() != "" {
+			return nil, ErrUnprotectedNonce
+		}
+
+		var err error
+		obj.Signatures[i].Header, err = obj.Signatures[i].mergedHeaders().sanitized()
+		if err != nil {
+			return nil, err
+		}
+
+		if obj.Signatures[i].header != nil {
+			obj.Signatures[i].Unprotected, err = obj.Signatures[i].header.sanitized()
+			if err != nil {
+				return nil, err
+			}
+		}
+
+		if obj.Signatures[i].protected != nil {
+			obj.Signatures[i].Protected, err = obj.Signatures[i].protected.sanitized()
+			if err != nil {
+				return nil, err
+			}
+		}
+
+		obj.Signatures[i].Signature = sig.Signature.bytes()
+
+		// As per RFC 7515 Section 4.1.3, only public keys are allowed to be embedded.
+		jwk := obj.Signatures[i].Header.JSONWebKey
+		if jwk != nil && (!jwk.Valid() || !jwk.IsPublic()) {
+			return nil, errors.New("square/go-jose: invalid embedded jwk, must be public key")
+		}
+
+		// Copy value of sig
+		original := sig
+
+		obj.Signatures[i].header = sig.Header
+		obj.Signatures[i].original = &original
+	}
+
+	return obj, nil
+}
+
+// parseSignedCompact parses a message in compact format.
+func parseSignedCompact(input string) (*JSONWebSignature, error) {
+	parts := strings.Split(input, ".")
+	if len(parts) != 3 {
+		return nil, fmt.Errorf("square/go-jose: compact JWS format must have three parts")
+	}
+
+	rawProtected, err := base64.RawURLEncoding.DecodeString(parts[0])
+	if err != nil {
+		return nil, err
+	}
+
+	payload, err := base64.RawURLEncoding.DecodeString(parts[1])
+	if err != nil {
+		return nil, err
+	}
+
+	signature, err := base64.RawURLEncoding.DecodeString(parts[2])
+	if err != nil {
+		return nil, err
+	}
+
+	raw := &rawJSONWebSignature{
+		Payload:   newBuffer(payload),
+		Protected: newBuffer(rawProtected),
+		Signature: newBuffer(signature),
+	}
+	return raw.sanitized()
+}
+
+// CompactSerialize serializes an object using the compact serialization format.
+func (obj JSONWebSignature) CompactSerialize() (string, error) {
+	if len(obj.Signatures) != 1 || obj.Signatures[0].header != nil || obj.Signatures[0].protected == nil {
+		return "", ErrNotSupported
+	}
+
+	serializedProtected := mustSerializeJSON(obj.Signatures[0].protected)
+
+	return fmt.Sprintf(
+		"%s.%s.%s",
+		base64.RawURLEncoding.EncodeToString(serializedProtected),
+		base64.RawURLEncoding.EncodeToString(obj.payload),
+		base64.RawURLEncoding.EncodeToString(obj.Signatures[0].Signature)), nil
+}
+
+// FullSerialize serializes an object using the full JSON serialization format.
+func (obj JSONWebSignature) FullSerialize() string {
+	raw := rawJSONWebSignature{
+		Payload: newBuffer(obj.payload),
+	}
+
+	if len(obj.Signatures) == 1 {
+		if obj.Signatures[0].protected != nil {
+			serializedProtected := mustSerializeJSON(obj.Signatures[0].protected)
+			raw.Protected = newBuffer(serializedProtected)
+		}
+		raw.Header = obj.Signatures[0].header
+		raw.Signature = newBuffer(obj.Signatures[0].Signature)
+	} else {
+		raw.Signatures = make([]rawSignatureInfo, len(obj.Signatures))
+		for i, signature := range obj.Signatures {
+			raw.Signatures[i] = rawSignatureInfo{
+				Header:    signature.header,
+				Signature: newBuffer(signature.Signature),
+			}
+
+			if signature.protected != nil {
+				raw.Signatures[i].Protected = newBuffer(mustSerializeJSON(signature.protected))
+			}
+		}
+	}
+
+	return string(mustSerializeJSON(raw))
+}

src/vendor/gopkg.in/square/go-jose.v2/opaque.go

@@ -0,0 +1,83 @@
+/*-
+ * Copyright 2018 Square Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package jose
+
+// OpaqueSigner is an interface that supports signing payloads with opaque
+// private key(s). Private key operations preformed by implementors may, for
+// example, occur in a hardware module. An OpaqueSigner may rotate signing keys
+// transparently to the user of this interface.
+type OpaqueSigner interface {
+	// Public returns the public key of the current signing key.
+	Public() *JSONWebKey
+	// Algs returns a list of supported signing algorithms.
+	Algs() []SignatureAlgorithm
+	// SignPayload signs a payload with the current signing key using the given
+	// algorithm.
+	SignPayload(payload []byte, alg SignatureAlgorithm) ([]byte, error)
+}
+
+type opaqueSigner struct {
+	signer OpaqueSigner
+}
+
+func newOpaqueSigner(alg SignatureAlgorithm, signer OpaqueSigner) (recipientSigInfo, error) {
+	var algSupported bool
+	for _, salg := range signer.Algs() {
+		if alg == salg {
+			algSupported = true
+			break
+		}
+	}
+	if !algSupported {
+		return recipientSigInfo{}, ErrUnsupportedAlgorithm
+	}
+
+	return recipientSigInfo{
+		sigAlg:    alg,
+		publicKey: signer.Public,
+		signer: &opaqueSigner{
+			signer: signer,
+		},
+	}, nil
+}
+
+func (o *opaqueSigner) signPayload(payload []byte, alg SignatureAlgorithm) (Signature, error) {
+	out, err := o.signer.SignPayload(payload, alg)
+	if err != nil {
+		return Signature{}, err
+	}
+
+	return Signature{
+		Signature: out,
+		protected: &rawHeader{},
+	}, nil
+}
+
+// OpaqueVerifier is an interface that supports verifying payloads with opaque
+// public key(s). An OpaqueSigner may rotate signing keys transparently to the
+// user of this interface.
+type OpaqueVerifier interface {
+	VerifyPayload(payload []byte, signature []byte, alg SignatureAlgorithm) error
+}
+
+type opaqueVerifier struct {
+	verifier OpaqueVerifier
+}
+
+func (o *opaqueVerifier) verifyPayload(payload []byte, signature []byte, alg SignatureAlgorithm) error {
+	return o.verifier.VerifyPayload(payload, signature, alg)
+}

src/vendor/gopkg.in/square/go-jose.v2/shared.go

@@ -0,0 +1,499 @@
+/*-
+ * Copyright 2014 Square Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package jose
+
+import (
+	"crypto/elliptic"
+	"crypto/x509"
+	"encoding/base64"
+	"errors"
+	"fmt"
+
+	"gopkg.in/square/go-jose.v2/json"
+)
+
+// KeyAlgorithm represents a key management algorithm.
+type KeyAlgorithm string
+
+// SignatureAlgorithm represents a signature (or MAC) algorithm.
+type SignatureAlgorithm string
+
+// ContentEncryption represents a content encryption algorithm.
+type ContentEncryption string
+
+// CompressionAlgorithm represents an algorithm used for plaintext compression.
+type CompressionAlgorithm string
+
+// ContentType represents type of the contained data.
+type ContentType string
+
+var (
+	// ErrCryptoFailure represents an error in cryptographic primitive. This
+	// occurs when, for example, a message had an invalid authentication tag or
+	// could not be decrypted.
+	ErrCryptoFailure = errors.New("square/go-jose: error in cryptographic primitive")
+
+	// ErrUnsupportedAlgorithm indicates that a selected algorithm is not
+	// supported. This occurs when trying to instantiate an encrypter for an
+	// algorithm that is not yet implemented.
+	ErrUnsupportedAlgorithm = errors.New("square/go-jose: unknown/unsupported algorithm")
+
+	// ErrUnsupportedKeyType indicates that the given key type/format is not
+	// supported. This occurs when trying to instantiate an encrypter and passing
+	// it a key of an unrecognized type or with unsupported parameters, such as
+	// an RSA private key with more than two primes.
+	ErrUnsupportedKeyType = errors.New("square/go-jose: unsupported key type/format")
+
+	// ErrInvalidKeySize indicates that the given key is not the correct size
+	// for the selected algorithm. This can occur, for example, when trying to
+	// encrypt with AES-256 but passing only a 128-bit key as input.
+	ErrInvalidKeySize = errors.New("square/go-jose: invalid key size for algorithm")
+
+	// ErrNotSupported serialization of object is not supported. This occurs when
+	// trying to compact-serialize an object which can't be represented in
+	// compact form.
+	ErrNotSupported = errors.New("square/go-jose: compact serialization not supported for object")
+
+	// ErrUnprotectedNonce indicates that while parsing a JWS or JWE object, a
+	// nonce header parameter was included in an unprotected header object.
+	ErrUnprotectedNonce = errors.New("square/go-jose: Nonce parameter included in unprotected header")
+)
+
+// Key management algorithms
+const (
+	ED25519            = KeyAlgorithm("ED25519")
+	RSA1_5             = KeyAlgorithm("RSA1_5")             // RSA-PKCS1v1.5
+	RSA_OAEP           = KeyAlgorithm("RSA-OAEP")           // RSA-OAEP-SHA1
+	RSA_OAEP_256       = KeyAlgorithm("RSA-OAEP-256")       // RSA-OAEP-SHA256
+	A128KW             = KeyAlgorithm("A128KW")             // AES key wrap (128)
+	A192KW             = KeyAlgorithm("A192KW")             // AES key wrap (192)
+	A256KW             = KeyAlgorithm("A256KW")             // AES key wrap (256)
+	DIRECT             = KeyAlgorithm("dir")                // Direct encryption
+	ECDH_ES            = KeyAlgorithm("ECDH-ES")            // ECDH-ES
+	ECDH_ES_A128KW     = KeyAlgorithm("ECDH-ES+A128KW")     // ECDH-ES + AES key wrap (128)
+	ECDH_ES_A192KW     = KeyAlgorithm("ECDH-ES+A192KW")     // ECDH-ES + AES key wrap (192)
+	ECDH_ES_A256KW     = KeyAlgorithm("ECDH-ES+A256KW")     // ECDH-ES + AES key wrap (256)
+	A128GCMKW          = KeyAlgorithm("A128GCMKW")          // AES-GCM key wrap (128)
+	A192GCMKW          = KeyAlgorithm("A192GCMKW")          // AES-GCM key wrap (192)
+	A256GCMKW          = KeyAlgorithm("A256GCMKW")          // AES-GCM key wrap (256)
+	PBES2_HS256_A128KW = KeyAlgorithm("PBES2-HS256+A128KW") // PBES2 + HMAC-SHA256 + AES key wrap (128)
+	PBES2_HS384_A192KW = KeyAlgorithm("PBES2-HS384+A192KW") // PBES2 + HMAC-SHA384 + AES key wrap (192)
+	PBES2_HS512_A256KW = KeyAlgorithm("PBES2-HS512+A256KW") // PBES2 + HMAC-SHA512 + AES key wrap (256)
+)
+
+// Signature algorithms
+const (
+	EdDSA = SignatureAlgorithm("EdDSA")
+	HS256 = SignatureAlgorithm("HS256") // HMAC using SHA-256
+	HS384 = SignatureAlgorithm("HS384") // HMAC using SHA-384
+	HS512 = SignatureAlgorithm("HS512") // HMAC using SHA-512
+	RS256 = SignatureAlgorithm("RS256") // RSASSA-PKCS-v1.5 using SHA-256
+	RS384 = SignatureAlgorithm("RS384") // RSASSA-PKCS-v1.5 using SHA-384
+	RS512 = SignatureAlgorithm("RS512") // RSASSA-PKCS-v1.5 using SHA-512
+	ES256 = SignatureAlgorithm("ES256") // ECDSA using P-256 and SHA-256
+	ES384 = SignatureAlgorithm("ES384") // ECDSA using P-384 and SHA-384
+	ES512 = SignatureAlgorithm("ES512") // ECDSA using P-521 and SHA-512
+	PS256 = SignatureAlgorithm("PS256") // RSASSA-PSS using SHA256 and MGF1-SHA256
+	PS384 = SignatureAlgorithm("PS384") // RSASSA-PSS using SHA384 and MGF1-SHA384
+	PS512 = SignatureAlgorithm("PS512") // RSASSA-PSS using SHA512 and MGF1-SHA512
+)
+
+// Content encryption algorithms
+const (
+	A128CBC_HS256 = ContentEncryption("A128CBC-HS256") // AES-CBC + HMAC-SHA256 (128)
+	A192CBC_HS384 = ContentEncryption("A192CBC-HS384") // AES-CBC + HMAC-SHA384 (192)
+	A256CBC_HS512 = ContentEncryption("A256CBC-HS512") // AES-CBC + HMAC-SHA512 (256)
+	A128GCM       = ContentEncryption("A128GCM")       // AES-GCM (128)
+	A192GCM       = ContentEncryption("A192GCM")       // AES-GCM (192)
+	A256GCM       = ContentEncryption("A256GCM")       // AES-GCM (256)
+)
+
+// Compression algorithms
+const (
+	NONE    = CompressionAlgorithm("")    // No compression
+	DEFLATE = CompressionAlgorithm("DEF") // DEFLATE (RFC 1951)
+)
+
+// A key in the protected header of a JWS object. Use of the Header...
+// constants is preferred to enhance type safety.
+type HeaderKey string
+
+const (
+	HeaderType        HeaderKey = "typ" // string
+	HeaderContentType           = "cty" // string
+
+	// These are set by go-jose and shouldn't need to be set by consumers of the
+	// library.
+	headerAlgorithm   = "alg"  // string
+	headerEncryption  = "enc"  // ContentEncryption
+	headerCompression = "zip"  // CompressionAlgorithm
+	headerCritical    = "crit" // []string
+
+	headerAPU = "apu" // *byteBuffer
+	headerAPV = "apv" // *byteBuffer
+	headerEPK = "epk" // *JSONWebKey
+	headerIV  = "iv"  // *byteBuffer
+	headerTag = "tag" // *byteBuffer
+	headerX5c = "x5c" // []*x509.Certificate
+
+	headerJWK   = "jwk"   // *JSONWebKey
+	headerKeyID = "kid"   // string
+	headerNonce = "nonce" // string
+
+	headerP2C = "p2c" // *byteBuffer (int)
+	headerP2S = "p2s" // *byteBuffer ([]byte)
+
+)
+
+// rawHeader represents the JOSE header for JWE/JWS objects (used for parsing).
+//
+// The decoding of the constituent items is deferred because we want to marshal
+// some members into particular structs rather than generic maps, but at the
+// same time we need to receive any extra fields unhandled by this library to
+// pass through to consuming code in case it wants to examine them.
+type rawHeader map[HeaderKey]*json.RawMessage
+
+// Header represents the read-only JOSE header for JWE/JWS objects.
+type Header struct {
+	KeyID      string
+	JSONWebKey *JSONWebKey
+	Algorithm  string
+	Nonce      string
+
+	// Unverified certificate chain parsed from x5c header.
+	certificates []*x509.Certificate
+
+	// Any headers not recognised above get unmarshaled
+	// from JSON in a generic manner and placed in this map.
+	ExtraHeaders map[HeaderKey]interface{}
+}
+
+// Certificates verifies & returns the certificate chain present
+// in the x5c header field of a message, if one was present. Returns
+// an error if there was no x5c header present or the chain could
+// not be validated with the given verify options.
+func (h Header) Certificates(opts x509.VerifyOptions) ([][]*x509.Certificate, error) {
+	if len(h.certificates) == 0 {
+		return nil, errors.New("square/go-jose: no x5c header present in message")
+	}
+
+	leaf := h.certificates[0]
+	if opts.Intermediates == nil {
+		opts.Intermediates = x509.NewCertPool()
+		for _, intermediate := range h.certificates[1:] {
+			opts.Intermediates.AddCert(intermediate)
+		}
+	}
+
+	return leaf.Verify(opts)
+}
+
+func (parsed rawHeader) set(k HeaderKey, v interface{}) error {
+	b, err := json.Marshal(v)
+	if err != nil {
+		return err
+	}
+
+	parsed[k] = makeRawMessage(b)
+	return nil
+}
+
+// getString gets a string from the raw JSON, defaulting to "".
+func (parsed rawHeader) getString(k HeaderKey) string {
+	v, ok := parsed[k]
+	if !ok || v == nil {
+		return ""
+	}
+	var s string
+	err := json.Unmarshal(*v, &s)
+	if err != nil {
+		return ""
+	}
+	return s
+}
+
+// getByteBuffer gets a byte buffer from the raw JSON. Returns (nil, nil) if
+// not specified.
+func (parsed rawHeader) getByteBuffer(k HeaderKey) (*byteBuffer, error) {
+	v := parsed[k]
+	if v == nil {
+		return nil, nil
+	}
+	var bb *byteBuffer
+	err := json.Unmarshal(*v, &bb)
+	if err != nil {
+		return nil, err
+	}
+	return bb, nil
+}
+
+// getAlgorithm extracts parsed "alg" from the raw JSON as a KeyAlgorithm.
+func (parsed rawHeader) getAlgorithm() KeyAlgorithm {
+	return KeyAlgorithm(parsed.getString(headerAlgorithm))
+}
+
+// getSignatureAlgorithm extracts parsed "alg" from the raw JSON as a SignatureAlgorithm.
+func (parsed rawHeader) getSignatureAlgorithm() SignatureAlgorithm {
+	return SignatureAlgorithm(parsed.getString(headerAlgorithm))
+}
+
+// getEncryption extracts parsed "enc" from the raw JSON.
+func (parsed rawHeader) getEncryption() ContentEncryption {
+	return ContentEncryption(parsed.getString(headerEncryption))
+}
+
+// getCompression extracts parsed "zip" from the raw JSON.
+func (parsed rawHeader) getCompression() CompressionAlgorithm {
+	return CompressionAlgorithm(parsed.getString(headerCompression))
+}
+
+func (parsed rawHeader) getNonce() string {
+	return parsed.getString(headerNonce)
+}
+
+// getEPK extracts parsed "epk" from the raw JSON.
+func (parsed rawHeader) getEPK() (*JSONWebKey, error) {
+	v := parsed[headerEPK]
+	if v == nil {
+		return nil, nil
+	}
+	var epk *JSONWebKey
+	err := json.Unmarshal(*v, &epk)
+	if err != nil {
+		return nil, err
+	}
+	return epk, nil
+}
+
+// getAPU extracts parsed "apu" from the raw JSON.
+func (parsed rawHeader) getAPU() (*byteBuffer, error) {
+	return parsed.getByteBuffer(headerAPU)
+}
+
+// getAPV extracts parsed "apv" from the raw JSON.
+func (parsed rawHeader) getAPV() (*byteBuffer, error) {
+	return parsed.getByteBuffer(headerAPV)
+}
+
+// getIV extracts parsed "iv" frpom the raw JSON.
+func (parsed rawHeader) getIV() (*byteBuffer, error) {
+	return parsed.getByteBuffer(headerIV)
+}
+
+// getTag extracts parsed "tag" frpom the raw JSON.
+func (parsed rawHeader) getTag() (*byteBuffer, error) {
+	return parsed.getByteBuffer(headerTag)
+}
+
+// getJWK extracts parsed "jwk" from the raw JSON.
+func (parsed rawHeader) getJWK() (*JSONWebKey, error) {
+	v := parsed[headerJWK]
+	if v == nil {
+		return nil, nil
+	}
+	var jwk *JSONWebKey
+	err := json.Unmarshal(*v, &jwk)
+	if err != nil {
+		return nil, err
+	}
+	return jwk, nil
+}
+
+// getCritical extracts parsed "crit" from the raw JSON. If omitted, it
+// returns an empty slice.
+func (parsed rawHeader) getCritical() ([]string, error) {
+	v := parsed[headerCritical]
+	if v == nil {
+		return nil, nil
+	}
+
+	var q []string
+	err := json.Unmarshal(*v, &q)
+	if err != nil {
+		return nil, err
+	}
+	return q, nil
+}
+
+// getS2C extracts parsed "p2c" from the raw JSON.
+func (parsed rawHeader) getP2C() (int, error) {
+	v := parsed[headerP2C]
+	if v == nil {
+		return 0, nil
+	}
+
+	var p2c int
+	err := json.Unmarshal(*v, &p2c)
+	if err != nil {
+		return 0, err
+	}
+	return p2c, nil
+}
+
+// getS2S extracts parsed "p2s" from the raw JSON.
+func (parsed rawHeader) getP2S() (*byteBuffer, error) {
+	return parsed.getByteBuffer(headerP2S)
+}
+
+// sanitized produces a cleaned-up header object from the raw JSON.
+func (parsed rawHeader) sanitized() (h Header, err error) {
+	for k, v := range parsed {
+		if v == nil {
+			continue
+		}
+		switch k {
+		case headerJWK:
+			var jwk *JSONWebKey
+			err = json.Unmarshal(*v, &jwk)
+			if err != nil {
+				err = fmt.Errorf("failed to unmarshal JWK: %v: %#v", err, string(*v))
+				return
+			}
+			h.JSONWebKey = jwk
+		case headerKeyID:
+			var s string
+			err = json.Unmarshal(*v, &s)
+			if err != nil {
+				err = fmt.Errorf("failed to unmarshal key ID: %v: %#v", err, string(*v))
+				return
+			}
+			h.KeyID = s
+		case headerAlgorithm:
+			var s string
+			err = json.Unmarshal(*v, &s)
+			if err != nil {
+				err = fmt.Errorf("failed to unmarshal algorithm: %v: %#v", err, string(*v))
+				return
+			}
+			h.Algorithm = s
+		case headerNonce:
+			var s string
+			err = json.Unmarshal(*v, &s)
+			if err != nil {
+				err = fmt.Errorf("failed to unmarshal nonce: %v: %#v", err, string(*v))
+				return
+			}
+			h.Nonce = s
+		case headerX5c:
+			c := []string{}
+			err = json.Unmarshal(*v, &c)
+			if err != nil {
+				err = fmt.Errorf("failed to unmarshal x5c header: %v: %#v", err, string(*v))
+				return
+			}
+			h.certificates, err = parseCertificateChain(c)
+			if err != nil {
+				err = fmt.Errorf("failed to unmarshal x5c header: %v: %#v", err, string(*v))
+				return
+			}
+		default:
+			if h.ExtraHeaders == nil {
+				h.ExtraHeaders = map[HeaderKey]interface{}{}
+			}
+			var v2 interface{}
+			err = json.Unmarshal(*v, &v2)
+			if err != nil {
+				err = fmt.Errorf("failed to unmarshal value: %v: %#v", err, string(*v))
+				return
+			}
+			h.ExtraHeaders[k] = v2
+		}
+	}
+	return
+}
+
+func parseCertificateChain(chain []string) ([]*x509.Certificate, error) {
+	out := make([]*x509.Certificate, len(chain))
+	for i, cert := range chain {
+		raw, err := base64.StdEncoding.DecodeString(cert)
+		if err != nil {
+			return nil, err
+		}
+		out[i], err = x509.ParseCertificate(raw)
+		if err != nil {
+			return nil, err
+		}
+	}
+	return out, nil
+}
+
+func (dst rawHeader) isSet(k HeaderKey) bool {
+	dvr := dst[k]
+	if dvr == nil {
+		return false
+	}
+
+	var dv interface{}
+	err := json.Unmarshal(*dvr, &dv)
+	if err != nil {
+		return true
+	}
+
+	if dvStr, ok := dv.(string); ok {
+		return dvStr != ""
+	}
+
+	return true
+}
+
+// Merge headers from src into dst, giving precedence to headers from l.
+func (dst rawHeader) merge(src *rawHeader) {
+	if src == nil {
+		return
+	}
+
+	for k, v := range *src {
+		if dst.isSet(k) {
+			continue
+		}
+
+		dst[k] = v
+	}
+}
+
+// Get JOSE name of curve
+func curveName(crv elliptic.Curve) (string, error) {
+	switch crv {
+	case elliptic.P256():
+		return "P-256", nil
+	case elliptic.P384():
+		return "P-384", nil
+	case elliptic.P521():
+		return "P-521", nil
+	default:
+		return "", fmt.Errorf("square/go-jose: unsupported/unknown elliptic curve")
+	}
+}
+
+// Get size of curve in bytes
+func curveSize(crv elliptic.Curve) int {
+	bits := crv.Params().BitSize
+
+	div := bits / 8
+	mod := bits % 8
+
+	if mod == 0 {
+		return div
+	}
+
+	return div + 1
+}
+
+func makeRawMessage(b []byte) *json.RawMessage {
+	rm := json.RawMessage(b)
+	return &rm
+}

src/vendor/gopkg.in/square/go-jose.v2/signing.go

@@ -0,0 +1,389 @@
+/*-
+ * Copyright 2014 Square Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package jose
+
+import (
+	"crypto/ecdsa"
+	"crypto/rsa"
+	"encoding/base64"
+	"errors"
+	"fmt"
+
+	"golang.org/x/crypto/ed25519"
+
+	"gopkg.in/square/go-jose.v2/json"
+)
+
+// NonceSource represents a source of random nonces to go into JWS objects
+type NonceSource interface {
+	Nonce() (string, error)
+}
+
+// Signer represents a signer which takes a payload and produces a signed JWS object.
+type Signer interface {
+	Sign(payload []byte) (*JSONWebSignature, error)
+	Options() SignerOptions
+}
+
+// SigningKey represents an algorithm/key used to sign a message.
+type SigningKey struct {
+	Algorithm SignatureAlgorithm
+	Key       interface{}
+}
+
+// SignerOptions represents options that can be set when creating signers.
+type SignerOptions struct {
+	NonceSource NonceSource
+	EmbedJWK    bool
+
+	// Optional map of additional keys to be inserted into the protected header
+	// of a JWS object. Some specifications which make use of JWS like to insert
+	// additional values here. All values must be JSON-serializable.
+	ExtraHeaders map[HeaderKey]interface{}
+}
+
+// WithHeader adds an arbitrary value to the ExtraHeaders map, initializing it
+// if necessary. It returns itself and so can be used in a fluent style.
+func (so *SignerOptions) WithHeader(k HeaderKey, v interface{}) *SignerOptions {
+	if so.ExtraHeaders == nil {
+		so.ExtraHeaders = map[HeaderKey]interface{}{}
+	}
+	so.ExtraHeaders[k] = v
+	return so
+}
+
+// WithContentType adds a content type ("cty") header and returns the updated
+// SignerOptions.
+func (so *SignerOptions) WithContentType(contentType ContentType) *SignerOptions {
+	return so.WithHeader(HeaderContentType, contentType)
+}
+
+// WithType adds a type ("typ") header and returns the updated SignerOptions.
+func (so *SignerOptions) WithType(typ ContentType) *SignerOptions {
+	return so.WithHeader(HeaderType, typ)
+}
+
+type payloadSigner interface {
+	signPayload(payload []byte, alg SignatureAlgorithm) (Signature, error)
+}
+
+type payloadVerifier interface {
+	verifyPayload(payload []byte, signature []byte, alg SignatureAlgorithm) error
+}
+
+type genericSigner struct {
+	recipients   []recipientSigInfo
+	nonceSource  NonceSource
+	embedJWK     bool
+	extraHeaders map[HeaderKey]interface{}
+}
+
+type recipientSigInfo struct {
+	sigAlg    SignatureAlgorithm
+	publicKey func() *JSONWebKey
+	signer    payloadSigner
+}
+
+func staticPublicKey(jwk *JSONWebKey) func() *JSONWebKey {
+	return func() *JSONWebKey {
+		return jwk
+	}
+}
+
+// NewSigner creates an appropriate signer based on the key type
+func NewSigner(sig SigningKey, opts *SignerOptions) (Signer, error) {
+	return NewMultiSigner([]SigningKey{sig}, opts)
+}
+
+// NewMultiSigner creates a signer for multiple recipients
+func NewMultiSigner(sigs []SigningKey, opts *SignerOptions) (Signer, error) {
+	signer := &genericSigner{recipients: []recipientSigInfo{}}
+
+	if opts != nil {
+		signer.nonceSource = opts.NonceSource
+		signer.embedJWK = opts.EmbedJWK
+		signer.extraHeaders = opts.ExtraHeaders
+	}
+
+	for _, sig := range sigs {
+		err := signer.addRecipient(sig.Algorithm, sig.Key)
+		if err != nil {
+			return nil, err
+		}
+	}
+
+	return signer, nil
+}
+
+// newVerifier creates a verifier based on the key type
+func newVerifier(verificationKey interface{}) (payloadVerifier, error) {
+	switch verificationKey := verificationKey.(type) {
+	case ed25519.PublicKey:
+		return &edEncrypterVerifier{
+			publicKey: verificationKey,
+		}, nil
+	case *rsa.PublicKey:
+		return &rsaEncrypterVerifier{
+			publicKey: verificationKey,
+		}, nil
+	case *ecdsa.PublicKey:
+		return &ecEncrypterVerifier{
+			publicKey: verificationKey,
+		}, nil
+	case []byte:
+		return &symmetricMac{
+			key: verificationKey,
+		}, nil
+	case JSONWebKey:
+		return newVerifier(verificationKey.Key)
+	case *JSONWebKey:
+		return newVerifier(verificationKey.Key)
+	}
+	if ov, ok := verificationKey.(OpaqueVerifier); ok {
+		return &opaqueVerifier{verifier: ov}, nil
+	}
+	return nil, ErrUnsupportedKeyType
+}
+
+func (ctx *genericSigner) addRecipient(alg SignatureAlgorithm, signingKey interface{}) error {
+	recipient, err := makeJWSRecipient(alg, signingKey)
+	if err != nil {
+		return err
+	}
+
+	ctx.recipients = append(ctx.recipients, recipient)
+	return nil
+}
+
+func makeJWSRecipient(alg SignatureAlgorithm, signingKey interface{}) (recipientSigInfo, error) {
+	switch signingKey := signingKey.(type) {
+	case ed25519.PrivateKey:
+		return newEd25519Signer(alg, signingKey)
+	case *rsa.PrivateKey:
+		return newRSASigner(alg, signingKey)
+	case *ecdsa.PrivateKey:
+		return newECDSASigner(alg, signingKey)
+	case []byte:
+		return newSymmetricSigner(alg, signingKey)
+	case JSONWebKey:
+		return newJWKSigner(alg, signingKey)
+	case *JSONWebKey:
+		return newJWKSigner(alg, *signingKey)
+	}
+	if signer, ok := signingKey.(OpaqueSigner); ok {
+		return newOpaqueSigner(alg, signer)
+	}
+	return recipientSigInfo{}, ErrUnsupportedKeyType
+}
+
+func newJWKSigner(alg SignatureAlgorithm, signingKey JSONWebKey) (recipientSigInfo, error) {
+	recipient, err := makeJWSRecipient(alg, signingKey.Key)
+	if err != nil {
+		return recipientSigInfo{}, err
+	}
+	if recipient.publicKey != nil && recipient.publicKey() != nil {
+		// recipient.publicKey is a JWK synthesized for embedding when recipientSigInfo
+		// was created for the inner key (such as a RSA or ECDSA public key). It contains
+		// the pub key for embedding, but doesn't have extra params like key id.
+		publicKey := signingKey
+		publicKey.Key = recipient.publicKey().Key
+		recipient.publicKey = staticPublicKey(&publicKey)
+
+		// This should be impossible, but let's check anyway.
+		if !recipient.publicKey().IsPublic() {
+			return recipientSigInfo{}, errors.New("square/go-jose: public key was unexpectedly not public")
+		}
+	}
+	return recipient, nil
+}
+
+func (ctx *genericSigner) Sign(payload []byte) (*JSONWebSignature, error) {
+	obj := &JSONWebSignature{}
+	obj.payload = payload
+	obj.Signatures = make([]Signature, len(ctx.recipients))
+
+	for i, recipient := range ctx.recipients {
+		protected := map[HeaderKey]interface{}{
+			headerAlgorithm: string(recipient.sigAlg),
+		}
+
+		if recipient.publicKey != nil && recipient.publicKey() != nil {
+			// We want to embed the JWK or set the kid header, but not both. Having a protected
+			// header that contains an embedded JWK while also simultaneously containing the kid
+			// header is confusing, and at least in ACME the two are considered to be mutually
+			// exclusive. The fact that both can exist at the same time is a somewhat unfortunate
+			// result of the JOSE spec. We've decided that this library will only include one or
+			// the other to avoid this confusion.
+			//
+			// See https://github.com/square/go-jose/issues/157 for more context.
+			if ctx.embedJWK {
+				protected[headerJWK] = recipient.publicKey()
+			} else {
+				protected[headerKeyID] = recipient.publicKey().KeyID
+			}
+		}
+
+		if ctx.nonceSource != nil {
+			nonce, err := ctx.nonceSource.Nonce()
+			if err != nil {
+				return nil, fmt.Errorf("square/go-jose: Error generating nonce: %v", err)
+			}
+			protected[headerNonce] = nonce
+		}
+
+		for k, v := range ctx.extraHeaders {
+			protected[k] = v
+		}
+
+		serializedProtected := mustSerializeJSON(protected)
+
+		input := []byte(fmt.Sprintf("%s.%s",
+			base64.RawURLEncoding.EncodeToString(serializedProtected),
+			base64.RawURLEncoding.EncodeToString(payload)))
+
+		signatureInfo, err := recipient.signer.signPayload(input, recipient.sigAlg)
+		if err != nil {
+			return nil, err
+		}
+
+		signatureInfo.protected = &rawHeader{}
+		for k, v := range protected {
+			b, err := json.Marshal(v)
+			if err != nil {
+				return nil, fmt.Errorf("square/go-jose: Error marshalling item %#v: %v", k, err)
+			}
+			(*signatureInfo.protected)[k] = makeRawMessage(b)
+		}
+		obj.Signatures[i] = signatureInfo
+	}
+
+	return obj, nil
+}
+
+func (ctx *genericSigner) Options() SignerOptions {
+	return SignerOptions{
+		NonceSource:  ctx.nonceSource,
+		EmbedJWK:     ctx.embedJWK,
+		ExtraHeaders: ctx.extraHeaders,
+	}
+}
+
+// Verify validates the signature on the object and returns the payload.
+// This function does not support multi-signature, if you desire multi-sig
+// verification use VerifyMulti instead.
+//
+// Be careful when verifying signatures based on embedded JWKs inside the
+// payload header. You cannot assume that the key received in a payload is
+// trusted.
+func (obj JSONWebSignature) Verify(verificationKey interface{}) ([]byte, error) {
+	err := obj.DetachedVerify(obj.payload, verificationKey)
+	if err != nil {
+		return nil, err
+	}
+	return obj.payload, nil
+}
+
+// UnsafePayloadWithoutVerification returns the payload without
+// verifying it. The content returned from this function cannot be
+// trusted.
+func (obj JSONWebSignature) UnsafePayloadWithoutVerification() []byte {
+	return obj.payload
+}
+
+// DetachedVerify validates a detached signature on the given payload. In
+// most cases, you will probably want to use Verify instead. DetachedVerify
+// is only useful if you have a payload and signature that are separated from
+// each other.
+func (obj JSONWebSignature) DetachedVerify(payload []byte, verificationKey interface{}) error {
+	verifier, err := newVerifier(verificationKey)
+	if err != nil {
+		return err
+	}
+
+	if len(obj.Signatures) > 1 {
+		return errors.New("square/go-jose: too many signatures in payload; expecting only one")
+	}
+
+	signature := obj.Signatures[0]
+	headers := signature.mergedHeaders()
+	critical, err := headers.getCritical()
+	if err != nil {
+		return err
+	}
+	if len(critical) > 0 {
+		// Unsupported crit header
+		return ErrCryptoFailure
+	}
+
+	input := obj.computeAuthData(payload, &signature)
+	alg := headers.getSignatureAlgorithm()
+	err = verifier.verifyPayload(input, signature.Signature, alg)
+	if err == nil {
+		return nil
+	}
+
+	return ErrCryptoFailure
+}
+
+// VerifyMulti validates (one of the multiple) signatures on the object and
+// returns the index of the signature that was verified, along with the signature
+// object and the payload. We return the signature and index to guarantee that
+// callers are getting the verified value.
+func (obj JSONWebSignature) VerifyMulti(verificationKey interface{}) (int, Signature, []byte, error) {
+	idx, sig, err := obj.DetachedVerifyMulti(obj.payload, verificationKey)
+	if err != nil {
+		return -1, Signature{}, nil, err
+	}
+	return idx, sig, obj.payload, nil
+}
+
+// DetachedVerifyMulti validates a detached signature on the given payload with
+// a signature/object that has potentially multiple signers. This returns the index
+// of the signature that was verified, along with the signature object. We return
+// the signature and index to guarantee that callers are getting the verified value.
+//
+// In most cases, you will probably want to use Verify or VerifyMulti instead.
+// DetachedVerifyMulti is only useful if you have a payload and signature that are
+// separated from each other, and the signature can have multiple signers at the
+// same time.
+func (obj JSONWebSignature) DetachedVerifyMulti(payload []byte, verificationKey interface{}) (int, Signature, error) {
+	verifier, err := newVerifier(verificationKey)
+	if err != nil {
+		return -1, Signature{}, err
+	}
+
+	for i, signature := range obj.Signatures {
+		headers := signature.mergedHeaders()
+		critical, err := headers.getCritical()
+		if err != nil {
+			continue
+		}
+		if len(critical) > 0 {
+			// Unsupported crit header
+			continue
+		}
+
+		input := obj.computeAuthData(payload, &signature)
+		alg := headers.getSignatureAlgorithm()
+		err = verifier.verifyPayload(input, signature.Signature, alg)
+		if err == nil {
+			return i, signature, nil
+		}
+	}
+
+	return -1, Signature{}, ErrCryptoFailure
+}

src/vendor/gopkg.in/square/go-jose.v2/symmetric.go

@@ -0,0 +1,482 @@
+/*-
+ * Copyright 2014 Square Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package jose
+
+import (
+	"bytes"
+	"crypto/aes"
+	"crypto/cipher"
+	"crypto/hmac"
+	"crypto/rand"
+	"crypto/sha256"
+	"crypto/sha512"
+	"crypto/subtle"
+	"errors"
+	"fmt"
+	"hash"
+	"io"
+
+	"golang.org/x/crypto/pbkdf2"
+	"gopkg.in/square/go-jose.v2/cipher"
+)
+
+// Random reader (stubbed out in tests)
+var RandReader = rand.Reader
+
+const (
+	// RFC7518 recommends a minimum of 1,000 iterations:
+	// https://tools.ietf.org/html/rfc7518#section-4.8.1.2
+	// NIST recommends a minimum of 10,000:
+	// https://pages.nist.gov/800-63-3/sp800-63b.html
+	// 1Password uses 100,000:
+	// https://support.1password.com/pbkdf2/
+	defaultP2C = 100000
+	// Default salt size: 128 bits
+	defaultP2SSize = 16
+)
+
+// Dummy key cipher for shared symmetric key mode
+type symmetricKeyCipher struct {
+	key []byte // Pre-shared content-encryption key
+	p2c int    // PBES2 Count
+	p2s []byte // PBES2 Salt Input
+}
+
+// Signer/verifier for MAC modes
+type symmetricMac struct {
+	key []byte
+}
+
+// Input/output from an AEAD operation
+type aeadParts struct {
+	iv, ciphertext, tag []byte
+}
+
+// A content cipher based on an AEAD construction
+type aeadContentCipher struct {
+	keyBytes     int
+	authtagBytes int
+	getAead      func(key []byte) (cipher.AEAD, error)
+}
+
+// Random key generator
+type randomKeyGenerator struct {
+	size int
+}
+
+// Static key generator
+type staticKeyGenerator struct {
+	key []byte
+}
+
+// Create a new content cipher based on AES-GCM
+func newAESGCM(keySize int) contentCipher {
+	return &aeadContentCipher{
+		keyBytes:     keySize,
+		authtagBytes: 16,
+		getAead: func(key []byte) (cipher.AEAD, error) {
+			aes, err := aes.NewCipher(key)
+			if err != nil {
+				return nil, err
+			}
+
+			return cipher.NewGCM(aes)
+		},
+	}
+}
+
+// Create a new content cipher based on AES-CBC+HMAC
+func newAESCBC(keySize int) contentCipher {
+	return &aeadContentCipher{
+		keyBytes:     keySize * 2,
+		authtagBytes: keySize,
+		getAead: func(key []byte) (cipher.AEAD, error) {
+			return josecipher.NewCBCHMAC(key, aes.NewCipher)
+		},
+	}
+}
+
+// Get an AEAD cipher object for the given content encryption algorithm
+func getContentCipher(alg ContentEncryption) contentCipher {
+	switch alg {
+	case A128GCM:
+		return newAESGCM(16)
+	case A192GCM:
+		return newAESGCM(24)
+	case A256GCM:
+		return newAESGCM(32)
+	case A128CBC_HS256:
+		return newAESCBC(16)
+	case A192CBC_HS384:
+		return newAESCBC(24)
+	case A256CBC_HS512:
+		return newAESCBC(32)
+	default:
+		return nil
+	}
+}
+
+// getPbkdf2Params returns the key length and hash function used in
+// pbkdf2.Key.
+func getPbkdf2Params(alg KeyAlgorithm) (int, func() hash.Hash) {
+	switch alg {
+	case PBES2_HS256_A128KW:
+		return 16, sha256.New
+	case PBES2_HS384_A192KW:
+		return 24, sha512.New384
+	case PBES2_HS512_A256KW:
+		return 32, sha512.New
+	default:
+		panic("invalid algorithm")
+	}
+}
+
+// getRandomSalt generates a new salt of the given size.
+func getRandomSalt(size int) ([]byte, error) {
+	salt := make([]byte, size)
+	_, err := io.ReadFull(RandReader, salt)
+	if err != nil {
+		return nil, err
+	}
+
+	return salt, nil
+}
+
+// newSymmetricRecipient creates a JWE encrypter based on AES-GCM key wrap.
+func newSymmetricRecipient(keyAlg KeyAlgorithm, key []byte) (recipientKeyInfo, error) {
+	switch keyAlg {
+	case DIRECT, A128GCMKW, A192GCMKW, A256GCMKW, A128KW, A192KW, A256KW:
+	case PBES2_HS256_A128KW, PBES2_HS384_A192KW, PBES2_HS512_A256KW:
+	default:
+		return recipientKeyInfo{}, ErrUnsupportedAlgorithm
+	}
+
+	return recipientKeyInfo{
+		keyAlg: keyAlg,
+		keyEncrypter: &symmetricKeyCipher{
+			key: key,
+		},
+	}, nil
+}
+
+// newSymmetricSigner creates a recipientSigInfo based on the given key.
+func newSymmetricSigner(sigAlg SignatureAlgorithm, key []byte) (recipientSigInfo, error) {
+	// Verify that key management algorithm is supported by this encrypter
+	switch sigAlg {
+	case HS256, HS384, HS512:
+	default:
+		return recipientSigInfo{}, ErrUnsupportedAlgorithm
+	}
+
+	return recipientSigInfo{
+		sigAlg: sigAlg,
+		signer: &symmetricMac{
+			key: key,
+		},
+	}, nil
+}
+
+// Generate a random key for the given content cipher
+func (ctx randomKeyGenerator) genKey() ([]byte, rawHeader, error) {
+	key := make([]byte, ctx.size)
+	_, err := io.ReadFull(RandReader, key)
+	if err != nil {
+		return nil, rawHeader{}, err
+	}
+
+	return key, rawHeader{}, nil
+}
+
+// Key size for random generator
+func (ctx randomKeyGenerator) keySize() int {
+	return ctx.size
+}
+
+// Generate a static key (for direct mode)
+func (ctx staticKeyGenerator) genKey() ([]byte, rawHeader, error) {
+	cek := make([]byte, len(ctx.key))
+	copy(cek, ctx.key)
+	return cek, rawHeader{}, nil
+}
+
+// Key size for static generator
+func (ctx staticKeyGenerator) keySize() int {
+	return len(ctx.key)
+}
+
+// Get key size for this cipher
+func (ctx aeadContentCipher) keySize() int {
+	return ctx.keyBytes
+}
+
+// Encrypt some data
+func (ctx aeadContentCipher) encrypt(key, aad, pt []byte) (*aeadParts, error) {
+	// Get a new AEAD instance
+	aead, err := ctx.getAead(key)
+	if err != nil {
+		return nil, err
+	}
+
+	// Initialize a new nonce
+	iv := make([]byte, aead.NonceSize())
+	_, err = io.ReadFull(RandReader, iv)
+	if err != nil {
+		return nil, err
+	}
+
+	ciphertextAndTag := aead.Seal(nil, iv, pt, aad)
+	offset := len(ciphertextAndTag) - ctx.authtagBytes
+
+	return &aeadParts{
+		iv:         iv,
+		ciphertext: ciphertextAndTag[:offset],
+		tag:        ciphertextAndTag[offset:],
+	}, nil
+}
+
+// Decrypt some data
+func (ctx aeadContentCipher) decrypt(key, aad []byte, parts *aeadParts) ([]byte, error) {
+	aead, err := ctx.getAead(key)
+	if err != nil {
+		return nil, err
+	}
+
+	if len(parts.iv) != aead.NonceSize() || len(parts.tag) < ctx.authtagBytes {
+		return nil, ErrCryptoFailure
+	}
+
+	return aead.Open(nil, parts.iv, append(parts.ciphertext, parts.tag...), aad)
+}
+
+// Encrypt the content encryption key.
+func (ctx *symmetricKeyCipher) encryptKey(cek []byte, alg KeyAlgorithm) (recipientInfo, error) {
+	switch alg {
+	case DIRECT:
+		return recipientInfo{
+			header: &rawHeader{},
+		}, nil
+	case A128GCMKW, A192GCMKW, A256GCMKW:
+		aead := newAESGCM(len(ctx.key))
+
+		parts, err := aead.encrypt(ctx.key, []byte{}, cek)
+		if err != nil {
+			return recipientInfo{}, err
+		}
+
+		header := &rawHeader{}
+		header.set(headerIV, newBuffer(parts.iv))
+		header.set(headerTag, newBuffer(parts.tag))
+
+		return recipientInfo{
+			header:       header,
+			encryptedKey: parts.ciphertext,
+		}, nil
+	case A128KW, A192KW, A256KW:
+		block, err := aes.NewCipher(ctx.key)
+		if err != nil {
+			return recipientInfo{}, err
+		}
+
+		jek, err := josecipher.KeyWrap(block, cek)
+		if err != nil {
+			return recipientInfo{}, err
+		}
+
+		return recipientInfo{
+			encryptedKey: jek,
+			header:       &rawHeader{},
+		}, nil
+	case PBES2_HS256_A128KW, PBES2_HS384_A192KW, PBES2_HS512_A256KW:
+		if len(ctx.p2s) == 0 {
+			salt, err := getRandomSalt(defaultP2SSize)
+			if err != nil {
+				return recipientInfo{}, err
+			}
+			ctx.p2s = salt
+		}
+
+		if ctx.p2c <= 0 {
+			ctx.p2c = defaultP2C
+		}
+
+		// salt is UTF8(Alg) || 0x00 || Salt Input
+		salt := bytes.Join([][]byte{[]byte(alg), ctx.p2s}, []byte{0x00})
+
+		// derive key
+		keyLen, h := getPbkdf2Params(alg)
+		key := pbkdf2.Key(ctx.key, salt, ctx.p2c, keyLen, h)
+
+		// use AES cipher with derived key
+		block, err := aes.NewCipher(key)
+		if err != nil {
+			return recipientInfo{}, err
+		}
+
+		jek, err := josecipher.KeyWrap(block, cek)
+		if err != nil {
+			return recipientInfo{}, err
+		}
+
+		header := &rawHeader{}
+		header.set(headerP2C, ctx.p2c)
+		header.set(headerP2S, newBuffer(ctx.p2s))
+
+		return recipientInfo{
+			encryptedKey: jek,
+			header:       header,
+		}, nil
+	}
+
+	return recipientInfo{}, ErrUnsupportedAlgorithm
+}
+
+// Decrypt the content encryption key.
+func (ctx *symmetricKeyCipher) decryptKey(headers rawHeader, recipient *recipientInfo, generator keyGenerator) ([]byte, error) {
+	switch headers.getAlgorithm() {
+	case DIRECT:
+		cek := make([]byte, len(ctx.key))
+		copy(cek, ctx.key)
+		return cek, nil
+	case A128GCMKW, A192GCMKW, A256GCMKW:
+		aead := newAESGCM(len(ctx.key))
+
+		iv, err := headers.getIV()
+		if err != nil {
+			return nil, fmt.Errorf("square/go-jose: invalid IV: %v", err)
+		}
+		tag, err := headers.getTag()
+		if err != nil {
+			return nil, fmt.Errorf("square/go-jose: invalid tag: %v", err)
+		}
+
+		parts := &aeadParts{
+			iv:         iv.bytes(),
+			ciphertext: recipient.encryptedKey,
+			tag:        tag.bytes(),
+		}
+
+		cek, err := aead.decrypt(ctx.key, []byte{}, parts)
+		if err != nil {
+			return nil, err
+		}
+
+		return cek, nil
+	case A128KW, A192KW, A256KW:
+		block, err := aes.NewCipher(ctx.key)
+		if err != nil {
+			return nil, err
+		}
+
+		cek, err := josecipher.KeyUnwrap(block, recipient.encryptedKey)
+		if err != nil {
+			return nil, err
+		}
+		return cek, nil
+	case PBES2_HS256_A128KW, PBES2_HS384_A192KW, PBES2_HS512_A256KW:
+		p2s, err := headers.getP2S()
+		if err != nil {
+			return nil, fmt.Errorf("square/go-jose: invalid P2S: %v", err)
+		}
+		if p2s == nil || len(p2s.data) == 0 {
+			return nil, fmt.Errorf("square/go-jose: invalid P2S: must be present")
+		}
+
+		p2c, err := headers.getP2C()
+		if err != nil {
+			return nil, fmt.Errorf("square/go-jose: invalid P2C: %v", err)
+		}
+		if p2c <= 0 {
+			return nil, fmt.Errorf("square/go-jose: invalid P2C: must be a positive integer")
+		}
+
+		// salt is UTF8(Alg) || 0x00 || Salt Input
+		alg := headers.getAlgorithm()
+		salt := bytes.Join([][]byte{[]byte(alg), p2s.bytes()}, []byte{0x00})
+
+		// derive key
+		keyLen, h := getPbkdf2Params(alg)
+		key := pbkdf2.Key(ctx.key, salt, p2c, keyLen, h)
+
+		// use AES cipher with derived key
+		block, err := aes.NewCipher(key)
+		if err != nil {
+			return nil, err
+		}
+
+		cek, err := josecipher.KeyUnwrap(block, recipient.encryptedKey)
+		if err != nil {
+			return nil, err
+		}
+		return cek, nil
+	}
+
+	return nil, ErrUnsupportedAlgorithm
+}
+
+// Sign the given payload
+func (ctx symmetricMac) signPayload(payload []byte, alg SignatureAlgorithm) (Signature, error) {
+	mac, err := ctx.hmac(payload, alg)
+	if err != nil {
+		return Signature{}, errors.New("square/go-jose: failed to compute hmac")
+	}
+
+	return Signature{
+		Signature: mac,
+		protected: &rawHeader{},
+	}, nil
+}
+
+// Verify the given payload
+func (ctx symmetricMac) verifyPayload(payload []byte, mac []byte, alg SignatureAlgorithm) error {
+	expected, err := ctx.hmac(payload, alg)
+	if err != nil {
+		return errors.New("square/go-jose: failed to compute hmac")
+	}
+
+	if len(mac) != len(expected) {
+		return errors.New("square/go-jose: invalid hmac")
+	}
+
+	match := subtle.ConstantTimeCompare(mac, expected)
+	if match != 1 {
+		return errors.New("square/go-jose: invalid hmac")
+	}
+
+	return nil
+}
+
+// Compute the HMAC based on the given alg value
+func (ctx symmetricMac) hmac(payload []byte, alg SignatureAlgorithm) ([]byte, error) {
+	var hash func() hash.Hash
+
+	switch alg {
+	case HS256:
+		hash = sha256.New
+	case HS384:
+		hash = sha512.New384
+	case HS512:
+		hash = sha512.New
+	default:
+		return nil, ErrUnsupportedAlgorithm
+	}
+
+	hmac := hmac.New(hash, ctx.key)
+
+	// According to documentation, Write() on hash never fails
+	_, _ = hmac.Write(payload)
+	return hmac.Sum(nil), nil
+}