From 00562d083b687fb566b09c0df8a05e90b86f9e5a Mon Sep 17 00:00:00 2001
From: Kyle Spearrin <kyle.spearrin@gmail.com>
Date: Mon, 27 Aug 2018 19:06:36 -0400
Subject: [PATCH] remakeEncKey

---
 src/abstractions/crypto.service.ts |  1 +
 src/services/crypto.service.ts     | 30 ++++++++++++++++++++----------
 2 files changed, 21 insertions(+), 10 deletions(-)

diff --git a/src/abstractions/crypto.service.ts b/src/abstractions/crypto.service.ts
index 8181ccf587..e333e5791b 100644
--- a/src/abstractions/crypto.service.ts
+++ b/src/abstractions/crypto.service.ts
@@ -32,6 +32,7 @@ export abstract class CryptoService {
     makeKeyPair: (key?: SymmetricCryptoKey) => Promise<[string, CipherString]>;
     hashPassword: (password: string, key: SymmetricCryptoKey) => Promise<string>;
     makeEncKey: (key: SymmetricCryptoKey) => Promise<[SymmetricCryptoKey, CipherString]>;
+    remakeEncKey: (key: SymmetricCryptoKey) => Promise<[SymmetricCryptoKey, CipherString]>
     encrypt: (plainValue: string | ArrayBuffer, key?: SymmetricCryptoKey) => Promise<CipherString>;
     encryptToBytes: (plainValue: ArrayBuffer, key?: SymmetricCryptoKey) => Promise<ArrayBuffer>;
     rsaEncrypt: (data: ArrayBuffer, publicKey?: ArrayBuffer, key?: SymmetricCryptoKey) => Promise<CipherString>;
diff --git a/src/services/crypto.service.ts b/src/services/crypto.service.ts
index 21e9d07852..dc0890eb31 100644
--- a/src/services/crypto.service.ts
+++ b/src/services/crypto.service.ts
@@ -318,16 +318,12 @@ export class CryptoService implements CryptoServiceAbstraction {
 
     async makeEncKey(key: SymmetricCryptoKey): Promise<[SymmetricCryptoKey, CipherString]> {
         const encKey = await this.cryptoFunctionService.randomBytes(64);
-        let encKeyEnc: CipherString = null;
-        if (key.key.byteLength === 32) {
-            const newKey = await this.stretchKey(key);
-            encKeyEnc = await this.encrypt(encKey, newKey);
-        } else if (key.key.byteLength === 64) {
-            encKeyEnc = await this.encrypt(encKey, key);
-        } else {
-            throw new Error('Invalid key size.');
-        }
-        return [new SymmetricCryptoKey(encKey), encKeyEnc];
+        return this.buildEncKey(key, encKey);
+    }
+
+    async remakeEncKey(key: SymmetricCryptoKey): Promise<[SymmetricCryptoKey, CipherString]> {
+        const encKey = await this.getEncKey();
+        return this.buildEncKey(key, encKey.key);
     }
 
     async encrypt(plainValue: string | ArrayBuffer, key?: SymmetricCryptoKey): Promise<CipherString> {
@@ -677,4 +673,18 @@ export class CryptoService implements CryptoServiceAbstraction {
         }
         return okm;
     }
+
+    private async buildEncKey(key: SymmetricCryptoKey, encKey: ArrayBuffer = null)
+        : Promise<[SymmetricCryptoKey, CipherString]> {
+        let encKeyEnc: CipherString = null;
+        if (key.key.byteLength === 32) {
+            const newKey = await this.stretchKey(key);
+            encKeyEnc = await this.encrypt(encKey, newKey);
+        } else if (key.key.byteLength === 64) {
+            encKeyEnc = await this.encrypt(encKey, key);
+        } else {
+            throw new Error('Invalid key size.');
+        }
+        return [new SymmetricCryptoKey(encKey), encKeyEnc];
+    }
 }