WordPress/wp-includes/http.php
Andrew Nacin 1ec392175c Additional checks when evaluating the safety of an HTTP request, to avoid false negatives.
* Check if the host is considered a safe redirect host.
 * Check if the host is another domain in a multisite installation.
 * Add a filter to control this.

This only occurs when the DNS resolution of a domain points elsewhere in an internal network, but only internally (and has its own public IP outside the network). This could be considered a bad configuration.

fixes #24646.



git-svn-id: http://core.svn.wordpress.org/trunk@24915 1a063a9b-81f0-0310-95a4-ce76da25c4cd
2013-07-31 06:44:57 +00:00

520 lines
14 KiB
PHP

<?php
/**
* Simple and uniform HTTP request API.
*
* Will eventually replace and standardize the WordPress HTTP requests made.
*
* @link http://trac.wordpress.org/ticket/4779 HTTP API Proposal
*
* @package WordPress
* @subpackage HTTP
* @since 2.7.0
*/
/**
* Returns the initialized WP_Http Object
*
* @since 2.7.0
* @access private
*
* @return WP_Http HTTP Transport object.
*/
function _wp_http_get_object() {
static $http;
if ( is_null($http) )
$http = new WP_Http();
return $http;
}
/**
* Retrieve the raw response from a safe HTTP request.
*
* This function is ideal when the HTTP request is being made to an arbitrary
* URL. The URL is validated to avoid redirection and request forgery attacks.
*
* @see wp_remote_request() For more information on the response array format
* and default arguments.
*
* @since 3.6.0
*
* @param string $url Site URL to retrieve.
* @param array $args Optional. Override the defaults.
* @return WP_Error|array The response or WP_Error on failure.
*/
function wp_safe_remote_request( $url, $args = array() ) {
$args['reject_unsafe_urls'] = true;
$http = _wp_http_get_object();
return $http->request( $url, $args );
}
/**
* Retrieve the raw response from a safe HTTP request using the GET method.
*
* This function is ideal when the HTTP request is being made to an arbitrary
* URL. The URL is validated to avoid redirection and request forgery attacks.
*
* @see wp_remote_request() For more information on the response array format
* and default arguments.
*
* @since 3.6.0
*
* @param string $url Site URL to retrieve.
* @param array $args Optional. Override the defaults.
* @return WP_Error|array The response or WP_Error on failure.
*/
function wp_safe_remote_get( $url, $args = array() ) {
$args['reject_unsafe_urls'] = true;
$http = _wp_http_get_object();
return $http->get( $url, $args );
}
/**
* Retrieve the raw response from a safe HTTP request using the POST method.
*
* This function is ideal when the HTTP request is being made to an arbitrary
* URL. The URL is validated to avoid redirection and request forgery attacks.
*
* @see wp_remote_request() For more information on the response array format
* and default arguments.
*
* @since 3.6.0
*
* @param string $url Site URL to retrieve.
* @param array $args Optional. Override the defaults.
* @return WP_Error|array The response or WP_Error on failure.
*/
function wp_safe_remote_post( $url, $args = array() ) {
$args['reject_unsafe_urls'] = true;
$http = _wp_http_get_object();
return $http->post( $url, $args );
}
/**
* Retrieve the raw response from a safe HTTP request using the HEAD method.
*
* This function is ideal when the HTTP request is being made to an arbitrary
* URL. The URL is validated to avoid redirection and request forgery attacks.
*
* @see wp_remote_request() For more information on the response array format
* and default arguments.
*
* @since 3.6.0
*
* @param string $url Site URL to retrieve.
* @param array $args Optional. Override the defaults.
* @return WP_Error|array The response or WP_Error on failure.
*/
function wp_safe_remote_head( $url, $args = array() ) {
$args['reject_unsafe_urls'] = true;
$http = _wp_http_get_object();
return $http->head( $url, $args );
}
/**
* Retrieve the raw response from the HTTP request.
*
* The array structure is a little complex.
*
* <code>
* $res = array( 'headers' => array(), 'response' => array('code' => int, 'message' => string) );
* </code>
*
* All of the headers in $res['headers'] are with the name as the key and the
* value as the value. So to get the User-Agent, you would do the following.
*
* <code>
* $user_agent = $res['headers']['user-agent'];
* </code>
*
* The body is the raw response content and can be retrieved from $res['body'].
*
* This function is called first to make the request and there are other API
* functions to abstract out the above convoluted setup.
*
* List of default arguments:
* 'method' => 'GET'
* - Default 'GET' for wp_remote_get()
* - Default 'POST' for wp_remote_post()
* - Default 'HEAD' for wp_remote_head()
* 'timeout' => 5
* 'redirection' => 5
* 'httpversion' => '1.0'
* 'user-agent' => 'WordPress/' . $wp_version . '; ' . get_bloginfo( 'url' )
* 'blocking' => true
* 'headers' => array()
* 'cookies' => array()
* 'body' => null
* 'compress' => false,
* 'decompress' => true,
* 'sslverify' => true,
* 'stream' => false,
* 'filename' => null
*
* @since 2.7.0
*
* @param string $url Site URL to retrieve.
* @param array $args Optional. Override the defaults.
* @return WP_Error|array The response or WP_Error on failure.
*/
function wp_remote_request($url, $args = array()) {
$objFetchSite = _wp_http_get_object();
return $objFetchSite->request($url, $args);
}
/**
* Retrieve the raw response from the HTTP request using the GET method.
*
* @see wp_remote_request() For more information on the response array format and default arguments.
*
* @since 2.7.0
*
* @param string $url Site URL to retrieve.
* @param array $args Optional. Override the defaults.
* @return WP_Error|array The response or WP_Error on failure.
*/
function wp_remote_get($url, $args = array()) {
$objFetchSite = _wp_http_get_object();
return $objFetchSite->get($url, $args);
}
/**
* Retrieve the raw response from the HTTP request using the POST method.
*
* @see wp_remote_request() For more information on the response array format and default arguments.
*
* @since 2.7.0
*
* @param string $url Site URL to retrieve.
* @param array $args Optional. Override the defaults.
* @return WP_Error|array The response or WP_Error on failure.
*/
function wp_remote_post($url, $args = array()) {
$objFetchSite = _wp_http_get_object();
return $objFetchSite->post($url, $args);
}
/**
* Retrieve the raw response from the HTTP request using the HEAD method.
*
* @see wp_remote_request() For more information on the response array format and default arguments.
*
* @since 2.7.0
*
* @param string $url Site URL to retrieve.
* @param array $args Optional. Override the defaults.
* @return WP_Error|array The response or WP_Error on failure.
*/
function wp_remote_head($url, $args = array()) {
$objFetchSite = _wp_http_get_object();
return $objFetchSite->head($url, $args);
}
/**
* Retrieve only the headers from the raw response.
*
* @since 2.7.0
*
* @param array $response HTTP response.
* @return array The headers of the response. Empty array if incorrect parameter given.
*/
function wp_remote_retrieve_headers(&$response) {
if ( is_wp_error($response) || ! isset($response['headers']) || ! is_array($response['headers']))
return array();
return $response['headers'];
}
/**
* Retrieve a single header by name from the raw response.
*
* @since 2.7.0
*
* @param array $response
* @param string $header Header name to retrieve value from.
* @return string The header value. Empty string on if incorrect parameter given, or if the header doesn't exist.
*/
function wp_remote_retrieve_header(&$response, $header) {
if ( is_wp_error($response) || ! isset($response['headers']) || ! is_array($response['headers']))
return '';
if ( array_key_exists($header, $response['headers']) )
return $response['headers'][$header];
return '';
}
/**
* Retrieve only the response code from the raw response.
*
* Will return an empty array if incorrect parameter value is given.
*
* @since 2.7.0
*
* @param array $response HTTP response.
* @return string the response code. Empty string on incorrect parameter given.
*/
function wp_remote_retrieve_response_code(&$response) {
if ( is_wp_error($response) || ! isset($response['response']) || ! is_array($response['response']))
return '';
return $response['response']['code'];
}
/**
* Retrieve only the response message from the raw response.
*
* Will return an empty array if incorrect parameter value is given.
*
* @since 2.7.0
*
* @param array $response HTTP response.
* @return string The response message. Empty string on incorrect parameter given.
*/
function wp_remote_retrieve_response_message(&$response) {
if ( is_wp_error($response) || ! isset($response['response']) || ! is_array($response['response']))
return '';
return $response['response']['message'];
}
/**
* Retrieve only the body from the raw response.
*
* @since 2.7.0
*
* @param array $response HTTP response.
* @return string The body of the response. Empty string if no body or incorrect parameter given.
*/
function wp_remote_retrieve_body(&$response) {
if ( is_wp_error($response) || ! isset($response['body']) )
return '';
return $response['body'];
}
/**
* Determines if there is an HTTP Transport that can process this request.
*
* @since 3.2.0
*
* @param array $capabilities Array of capabilities to test or a wp_remote_request() $args array.
* @param string $url Optional. If given, will check if the URL requires SSL and adds that requirement to the capabilities array.
*
* @return bool
*/
function wp_http_supports( $capabilities = array(), $url = null ) {
$objFetchSite = _wp_http_get_object();
$capabilities = wp_parse_args( $capabilities );
$count = count( $capabilities );
// If we have a numeric $capabilities array, spoof a wp_remote_request() associative $args array
if ( $count && count( array_filter( array_keys( $capabilities ), 'is_numeric' ) ) == $count ) {
$capabilities = array_combine( array_values( $capabilities ), array_fill( 0, $count, true ) );
}
if ( $url && !isset( $capabilities['ssl'] ) ) {
$scheme = parse_url( $url, PHP_URL_SCHEME );
if ( 'https' == $scheme || 'ssl' == $scheme ) {
$capabilities['ssl'] = true;
}
}
return (bool) $objFetchSite->_get_first_available_transport( $capabilities );
}
/**
* Get the HTTP Origin of the current request.
*
* @since 3.4.0
*
* @return string URL of the origin. Empty string if no origin.
*/
function get_http_origin() {
$origin = '';
if ( ! empty ( $_SERVER[ 'HTTP_ORIGIN' ] ) )
$origin = $_SERVER[ 'HTTP_ORIGIN' ];
return apply_filters( 'http_origin', $origin );
}
/**
* Retrieve list of allowed http origins.
*
* @since 3.4.0
*
* @return array Array of origin URLs.
*/
function get_allowed_http_origins() {
$admin_origin = parse_url( admin_url() );
$home_origin = parse_url( home_url() );
// @todo preserve port?
$allowed_origins = array_unique( array(
'http://' . $admin_origin[ 'host' ],
'https://' . $admin_origin[ 'host' ],
'http://' . $home_origin[ 'host' ],
'https://' . $home_origin[ 'host' ],
) );
return apply_filters( 'allowed_http_origins' , $allowed_origins );
}
/**
* Determines if the http origin is an authorized one.
*
* @since 3.4.0
*
* @param string Origin URL. If not provided, the value of get_http_origin() is used.
* @return bool True if the origin is allowed. False otherwise.
*/
function is_allowed_http_origin( $origin = null ) {
$origin_arg = $origin;
if ( null === $origin )
$origin = get_http_origin();
if ( $origin && ! in_array( $origin, get_allowed_http_origins() ) )
$origin = '';
return apply_filters( 'allowed_http_origin', $origin, $origin_arg );
}
/**
* Send Access-Control-Allow-Origin and related headers if the current request
* is from an allowed origin.
*
* If the request is an OPTIONS request, the script exits with either access
* control headers sent, or a 403 response if the origin is not allowed. For
* other request methods, you will receive a return value.
*
* @since 3.4.0
*
* @return bool|string Returns the origin URL if headers are sent. Returns false
* if headers are not sent.
*/
function send_origin_headers() {
$origin = get_http_origin();
if ( is_allowed_http_origin( $origin ) ) {
@header( 'Access-Control-Allow-Origin: ' . $origin );
@header( 'Access-Control-Allow-Credentials: true' );
if ( 'OPTIONS' === $_SERVER['REQUEST_METHOD'] )
exit;
return $origin;
}
if ( 'OPTIONS' === $_SERVER['REQUEST_METHOD'] ) {
status_header( 403 );
exit;
}
return false;
}
/**
* Validate a URL for safe use in the HTTP API.
*
* @since 3.5.2
*
* @return mixed URL or false on failure.
*/
function wp_http_validate_url( $url ) {
$url = wp_kses_bad_protocol( $url, array( 'http', 'https' ) );
if ( ! $url )
return false;
$parsed_url = @parse_url( $url );
if ( ! $parsed_url || empty( $parsed_url['host'] ) )
return false;
if ( isset( $parsed_url['user'] ) || isset( $parsed_url['pass'] ) )
return false;
if ( false !== strpos( $parsed_url['host'], ':' ) )
return false;
$parsed_home = @parse_url( get_option( 'home' ) );
$same_host = strtolower( $parsed_home['host'] ) === strtolower( $parsed_url['host'] );
if ( ! $same_host ) {
$host = trim( $parsed_url['host'], '.' );
if ( preg_match( '#^\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}$#', $host ) ) {
$ip = $host;
} else {
$ip = gethostbyname( $host );
if ( $ip === $host ) // Error condition for gethostbyname()
$ip = false;
}
if ( $ip ) {
$parts = array_map( 'intval', explode( '.', $ip ) );
if ( '127.0.0.1' === $ip
|| ( 10 === $parts[0] )
|| ( 172 === $parts[0] && 16 <= $parts[1] && 31 >= $parts[1] )
|| ( 192 === $parts[0] && 168 === $parts[1] )
) {
// If host appears local, reject unless specifically allowed.
if ( ! apply_filters( 'http_request_host_is_external', false, $host, $url ) )
return false;
}
}
}
if ( empty( $parsed_url['port'] ) )
return $url;
$port = $parsed_url['port'];
if ( 80 === $port || 443 === $port || 8080 === $port )
return $url;
if ( $parsed_home && $same_host && $parsed_home['port'] === $port )
return $url;
return false;
}
/**
* Whitelists allowed redirect hosts for safe HTTP requests as well.
*
* Attached to the http_request_host_is_external filter.
*
* @since 3.6.0
*
* @param bool $is_external
* @param string $host
* @return bool
*/
function allowed_http_request_hosts( $is_external, $host ) {
if ( ! $is_external && wp_validate_redirect( 'http://' . $host ) )
$is_external = true;
return $is_external;
}
/**
* Whitelists any domain in a multisite installation for safe HTTP requests.
*
* Attached to the http_request_host_is_external filter.
*
* @since 3.6.0
*
* @param bool $is_external
* @param string $host
* @return bool
*/
function ms_allowed_http_request_hosts( $is_external, $host ) {
global $wpdb, $current_site;
static $queried = array();
if ( $is_external )
return $is_external;
if ( $host === $current_site->domain )
return true;
if ( isset( $queried[ $host ] ) )
return $queried[ $host ];
$queried[ $host ] = (bool) $wpdb->get_var( $wpdb->prepare( "SELECT domain FROM $wpdb->blogs WHERE domain = %s LIMIT 1", $host ) );
return $queried[ $host ];
}