web/wp-includes/class-http.php
changeset 194 32102edaa81b
child 204 09a1c134465b
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/web/wp-includes/class-http.php	Mon Nov 19 18:26:13 2012 +0100
@@ -0,0 +1,1789 @@
+<?php
+/**
+ * Simple and uniform HTTP request API.
+ *
+ * Standardizes the HTTP requests for WordPress. Handles cookies, gzip encoding and decoding, chunk
+ * decoding, if HTTP 1.1 and various other difficult HTTP protocol implementations.
+ *
+ * @link http://trac.wordpress.org/ticket/4779 HTTP API Proposal
+ *
+ * @package WordPress
+ * @subpackage HTTP
+ * @since 2.7.0
+ */
+
+/**
+ * WordPress HTTP Class for managing HTTP Transports and making HTTP requests.
+ *
+ * This class is called for the functionality of making HTTP requests and replaces Snoopy
+ * functionality. There is no available functionality to add HTTP transport implementations, since
+ * most of the HTTP transports are added and available for use.
+ *
+ * There are no properties, because none are needed and for performance reasons. Some of the
+ * functions are static and while they do have some overhead over functions in PHP4, the purpose is
+ * maintainability. When PHP5 is finally the requirement, it will be easy to add the static keyword
+ * to the code. It is not as easy to convert a function to a method after enough code uses the old
+ * way.
+ *
+ * Debugging includes several actions, which pass different variables for debugging the HTTP API.
+ *
+ * @package WordPress
+ * @subpackage HTTP
+ * @since 2.7.0
+ */
+class WP_Http {
+
+	/**
+	 * Send a HTTP request to a URI.
+	 *
+	 * The body and headers are part of the arguments. The 'body' argument is for the body and will
+	 * accept either a string or an array. The 'headers' argument should be an array, but a string
+	 * is acceptable. If the 'body' argument is an array, then it will automatically be escaped
+	 * using http_build_query().
+	 *
+	 * The only URI that are supported in the HTTP Transport implementation are the HTTP and HTTPS
+	 * protocols. HTTP and HTTPS are assumed so the server might not know how to handle the send
+	 * headers. Other protocols are unsupported and most likely will fail.
+	 *
+	 * The defaults are 'method', 'timeout', 'redirection', 'httpversion', 'blocking' and
+	 * 'user-agent'.
+	 *
+	 * Accepted 'method' values are 'GET', 'POST', and 'HEAD', some transports technically allow
+	 * others, but should not be assumed. The 'timeout' is used to sent how long the connection
+	 * should stay open before failing when no response. 'redirection' is used to track how many
+	 * redirects were taken and used to sent the amount for other transports, but not all transports
+	 * accept setting that value.
+	 *
+	 * The 'httpversion' option is used to sent the HTTP version and accepted values are '1.0', and
+	 * '1.1' and should be a string. Version 1.1 is not supported, because of chunk response. The
+	 * 'user-agent' option is the user-agent and is used to replace the default user-agent, which is
+	 * 'WordPress/WP_Version', where WP_Version is the value from $wp_version.
+	 *
+	 * 'blocking' is the default, which is used to tell the transport, whether it should halt PHP
+	 * while it performs the request or continue regardless. Actually, that isn't entirely correct.
+	 * Blocking mode really just means whether the fread should just pull what it can whenever it
+	 * gets bytes or if it should wait until it has enough in the buffer to read or finishes reading
+	 * the entire content. It doesn't actually always mean that PHP will continue going after making
+	 * the request.
+	 *
+	 * @access public
+	 * @since 2.7.0
+	 * @todo Refactor this code. The code in this method extends the scope of its original purpose
+	 *		and should be refactored to allow for cleaner abstraction and reduce duplication of the
+	 *		code. One suggestion is to create a class specifically for the arguments, however
+	 *		preliminary refactoring to this affect has affect more than just the scope of the
+	 *		arguments. Something to ponder at least.
+	 *
+	 * @param string $url URI resource.
+	 * @param str|array $args Optional. Override the defaults.
+	 * @return array|object Array containing 'headers', 'body', 'response', 'cookies', 'filename'. A WP_Error instance upon error
+	 */
+	function request( $url, $args = array() ) {
+		global $wp_version;
+
+		$defaults = array(
+			'method' => 'GET',
+			'timeout' => apply_filters( 'http_request_timeout', 5),
+			'redirection' => apply_filters( 'http_request_redirection_count', 5),
+			'httpversion' => apply_filters( 'http_request_version', '1.0'),
+			'user-agent' => apply_filters( 'http_headers_useragent', 'WordPress/' . $wp_version . '; ' . get_bloginfo( 'url' )  ),
+			'blocking' => true,
+			'headers' => array(),
+			'cookies' => array(),
+			'body' => null,
+			'compress' => false,
+			'decompress' => true,
+			'sslverify' => true,
+			'stream' => false,
+			'filename' => null
+		);
+
+		// Pre-parse for the HEAD checks.
+		$args = wp_parse_args( $args );
+
+		// By default, Head requests do not cause redirections.
+		if ( isset($args['method']) && 'HEAD' == $args['method'] )
+			$defaults['redirection'] = 0;
+
+		$r = wp_parse_args( $args, $defaults );
+		$r = apply_filters( 'http_request_args', $r, $url );
+
+		// Certain classes decrement this, store a copy of the original value for loop purposes.
+		$r['_redirection'] = $r['redirection'];
+
+		// Allow plugins to short-circuit the request
+		$pre = apply_filters( 'pre_http_request', false, $r, $url );
+		if ( false !== $pre )
+			return $pre;
+
+		$arrURL = parse_url( $url );
+
+		if ( empty( $url ) || empty( $arrURL['scheme'] ) )
+			return new WP_Error('http_request_failed', __('A valid URL was not provided.'));
+
+		if ( $this->block_request( $url ) )
+			return new WP_Error( 'http_request_failed', __( 'User has blocked requests through HTTP.' ) );
+
+		// Determine if this is a https call and pass that on to the transport functions
+		// so that we can blacklist the transports that do not support ssl verification
+		$r['ssl'] = $arrURL['scheme'] == 'https' || $arrURL['scheme'] == 'ssl';
+
+		// Determine if this request is to OUR install of WordPress
+		$homeURL = parse_url( get_bloginfo( 'url' ) );
+		$r['local'] = $homeURL['host'] == $arrURL['host'] || 'localhost' == $arrURL['host'];
+		unset( $homeURL );
+
+		// If we are streaming to a file but no filename was given drop it in the WP temp dir
+		// and pick it's name using the basename of the $url
+		if ( $r['stream']  && empty( $r['filename'] ) )
+			$r['filename'] = get_temp_dir() . basename( $url );
+
+		// Force some settings if we are streaming to a file and check for existence and perms of destination directory
+		if ( $r['stream'] ) {
+			$r['blocking'] = true;
+			if ( ! is_writable( dirname( $r['filename'] ) ) )
+				return new WP_Error( 'http_request_failed', __( 'Destination directory for file streaming does not exist or is not writable.' ) );
+		}
+
+		if ( is_null( $r['headers'] ) )
+			$r['headers'] = array();
+
+		if ( ! is_array( $r['headers'] ) ) {
+			$processedHeaders = WP_Http::processHeaders( $r['headers'] );
+			$r['headers'] = $processedHeaders['headers'];
+		}
+
+		if ( isset( $r['headers']['User-Agent'] ) ) {
+			$r['user-agent'] = $r['headers']['User-Agent'];
+			unset( $r['headers']['User-Agent'] );
+		}
+
+		if ( isset( $r['headers']['user-agent'] ) ) {
+			$r['user-agent'] = $r['headers']['user-agent'];
+			unset( $r['headers']['user-agent'] );
+		}
+
+		// Construct Cookie: header if any cookies are set
+		WP_Http::buildCookieHeader( $r );
+
+		if ( WP_Http_Encoding::is_available() )
+			$r['headers']['Accept-Encoding'] = WP_Http_Encoding::accept_encoding();
+
+		if ( empty($r['body']) ) {
+			$r['body'] = null;
+			// Some servers fail when sending content without the content-length header being set.
+			// Also, to fix another bug, we only send when doing POST and PUT and the content-length
+			// header isn't already set.
+			if ( ($r['method'] == 'POST' || $r['method'] == 'PUT') && ! isset( $r['headers']['Content-Length'] ) )
+				$r['headers']['Content-Length'] = 0;
+		} else {
+			if ( is_array( $r['body'] ) || is_object( $r['body'] ) ) {
+				$r['body'] = http_build_query( $r['body'], null, '&' );
+				if ( ! isset( $r['headers']['Content-Type'] ) )
+					$r['headers']['Content-Type'] = 'application/x-www-form-urlencoded; charset=' . get_option( 'blog_charset' );
+				$r['headers']['Content-Length'] = strlen( $r['body'] );
+			}
+
+			if ( ! isset( $r['headers']['Content-Length'] ) && ! isset( $r['headers']['content-length'] ) )
+				$r['headers']['Content-Length'] = strlen( $r['body'] );
+		}
+
+		return $this->_dispatch_request($url, $r);
+	}
+
+	/**
+	 * Tests which transports are capable of supporting the request.
+	 *
+	 * @since 3.2.0
+	 * @access private
+	 *
+	 * @param array $args Request arguments
+	 * @param string $url URL to Request
+	 *
+	 * @return string|false Class name for the first transport that claims to support the request. False if no transport claims to support the request.
+	 */
+	public function _get_first_available_transport( $args, $url = null ) {
+		$request_order = array( 'curl', 'streams', 'fsockopen' );
+
+		// Loop over each transport on each HTTP request looking for one which will serve this request's needs
+		foreach ( $request_order as $transport ) {
+			$class = 'WP_HTTP_' . $transport;
+
+			// Check to see if this transport is a possibility, calls the transport statically
+			if ( !call_user_func( array( $class, 'test' ), $args, $url ) )
+				continue;
+
+			return $class;
+		}
+
+		return false;
+	}
+
+	/**
+	 * Dispatches a HTTP request to a supporting transport.
+	 *
+	 * Tests each transport in order to find a transport which matches the request arguments.
+	 * Also caches the transport instance to be used later.
+	 *
+	 * The order for blocking requests is cURL, Streams, and finally Fsockopen.
+	 * The order for non-blocking requests is cURL, Streams and Fsockopen().
+	 *
+	 * There are currently issues with "localhost" not resolving correctly with DNS. This may cause
+	 * an error "failed to open stream: A connection attempt failed because the connected party did
+	 * not properly respond after a period of time, or established connection failed because [the]
+	 * connected host has failed to respond."
+	 *
+	 * @since 3.2.0
+	 * @access private
+	 *
+	 * @param string $url URL to Request
+	 * @param array $args Request arguments
+	 * @return array|object Array containing 'headers', 'body', 'response', 'cookies', 'filename'. A WP_Error instance upon error
+	 */
+	private function _dispatch_request( $url, $args ) {
+		static $transports = array();
+
+		$class = $this->_get_first_available_transport( $args, $url );
+		if ( !$class )
+			return new WP_Error( 'http_failure', __( 'There are no HTTP transports available which can complete the requested request.' ) );
+
+		// Transport claims to support request, instantiate it and give it a whirl.
+		if ( empty( $transports[$class] ) )
+			$transports[$class] = new $class;
+
+		$response = $transports[$class]->request( $url, $args );
+
+		do_action( 'http_api_debug', $response, 'response', $class, $args, $url );
+
+		if ( is_wp_error( $response ) )
+			return $response;
+
+		return apply_filters( 'http_response', $response, $args, $url );
+	}
+
+	/**
+	 * Uses the POST HTTP method.
+	 *
+	 * Used for sending data that is expected to be in the body.
+	 *
+	 * @access public
+	 * @since 2.7.0
+	 *
+	 * @param string $url URI resource.
+	 * @param str|array $args Optional. Override the defaults.
+	 * @return array|object Array containing 'headers', 'body', 'response', 'cookies', 'filename'. A WP_Error instance upon error
+	 */
+	function post($url, $args = array()) {
+		$defaults = array('method' => 'POST');
+		$r = wp_parse_args( $args, $defaults );
+		return $this->request($url, $r);
+	}
+
+	/**
+	 * Uses the GET HTTP method.
+	 *
+	 * Used for sending data that is expected to be in the body.
+	 *
+	 * @access public
+	 * @since 2.7.0
+	 *
+	 * @param string $url URI resource.
+	 * @param str|array $args Optional. Override the defaults.
+	 * @return array|object Array containing 'headers', 'body', 'response', 'cookies', 'filename'. A WP_Error instance upon error
+	 */
+	function get($url, $args = array()) {
+		$defaults = array('method' => 'GET');
+		$r = wp_parse_args( $args, $defaults );
+		return $this->request($url, $r);
+	}
+
+	/**
+	 * Uses the HEAD HTTP method.
+	 *
+	 * Used for sending data that is expected to be in the body.
+	 *
+	 * @access public
+	 * @since 2.7.0
+	 *
+	 * @param string $url URI resource.
+	 * @param str|array $args Optional. Override the defaults.
+	 * @return array|object Array containing 'headers', 'body', 'response', 'cookies', 'filename'. A WP_Error instance upon error
+	 */
+	function head($url, $args = array()) {
+		$defaults = array('method' => 'HEAD');
+		$r = wp_parse_args( $args, $defaults );
+		return $this->request($url, $r);
+	}
+
+	/**
+	 * Parses the responses and splits the parts into headers and body.
+	 *
+	 * @access public
+	 * @static
+	 * @since 2.7.0
+	 *
+	 * @param string $strResponse The full response string
+	 * @return array Array with 'headers' and 'body' keys.
+	 */
+	function processResponse($strResponse) {
+		$res = explode("\r\n\r\n", $strResponse, 2);
+
+		return array('headers' => $res[0], 'body' => isset($res[1]) ? $res[1] : '');
+	}
+
+	/**
+	 * Transform header string into an array.
+	 *
+	 * If an array is given then it is assumed to be raw header data with numeric keys with the
+	 * headers as the values. No headers must be passed that were already processed.
+	 *
+	 * @access public
+	 * @static
+	 * @since 2.7.0
+	 *
+	 * @param string|array $headers
+	 * @return array Processed string headers. If duplicate headers are encountered,
+	 * 					Then a numbered array is returned as the value of that header-key.
+	 */
+	public static function processHeaders($headers) {
+		// split headers, one per array element
+		if ( is_string($headers) ) {
+			// tolerate line terminator: CRLF = LF (RFC 2616 19.3)
+			$headers = str_replace("\r\n", "\n", $headers);
+			// unfold folded header fields. LWS = [CRLF] 1*( SP | HT ) <US-ASCII SP, space (32)>, <US-ASCII HT, horizontal-tab (9)> (RFC 2616 2.2)
+			$headers = preg_replace('/\n[ \t]/', ' ', $headers);
+			// create the headers array
+			$headers = explode("\n", $headers);
+		}
+
+		$response = array('code' => 0, 'message' => '');
+
+		// If a redirection has taken place, The headers for each page request may have been passed.
+		// In this case, determine the final HTTP header and parse from there.
+		for ( $i = count($headers)-1; $i >= 0; $i-- ) {
+			if ( !empty($headers[$i]) && false === strpos($headers[$i], ':') ) {
+				$headers = array_splice($headers, $i);
+				break;
+			}
+		}
+
+		$cookies = array();
+		$newheaders = array();
+		foreach ( (array) $headers as $tempheader ) {
+			if ( empty($tempheader) )
+				continue;
+
+			if ( false === strpos($tempheader, ':') ) {
+				$stack = explode(' ', $tempheader, 3);
+				$stack[] = '';
+				list( , $response['code'], $response['message']) = $stack;
+				continue;
+			}
+
+			list($key, $value) = explode(':', $tempheader, 2);
+
+			if ( !empty( $value ) ) {
+				$key = strtolower( $key );
+				if ( isset( $newheaders[$key] ) ) {
+					if ( !is_array($newheaders[$key]) )
+						$newheaders[$key] = array($newheaders[$key]);
+					$newheaders[$key][] = trim( $value );
+				} else {
+					$newheaders[$key] = trim( $value );
+				}
+				if ( 'set-cookie' == $key )
+					$cookies[] = new WP_Http_Cookie( $value );
+			}
+		}
+
+		return array('response' => $response, 'headers' => $newheaders, 'cookies' => $cookies);
+	}
+
+	/**
+	 * Takes the arguments for a ::request() and checks for the cookie array.
+	 *
+	 * If it's found, then it's assumed to contain WP_Http_Cookie objects, which are each parsed
+	 * into strings and added to the Cookie: header (within the arguments array). Edits the array by
+	 * reference.
+	 *
+	 * @access public
+	 * @version 2.8.0
+	 * @static
+	 *
+	 * @param array $r Full array of args passed into ::request()
+	 */
+	public static function buildCookieHeader( &$r ) {
+		if ( ! empty($r['cookies']) ) {
+			$cookies_header = '';
+			foreach ( (array) $r['cookies'] as $cookie ) {
+				$cookies_header .= $cookie->getHeaderValue() . '; ';
+			}
+			$cookies_header = substr( $cookies_header, 0, -2 );
+			$r['headers']['cookie'] = $cookies_header;
+		}
+	}
+
+	/**
+	 * Decodes chunk transfer-encoding, based off the HTTP 1.1 specification.
+	 *
+	 * Based off the HTTP http_encoding_dechunk function. Does not support UTF-8. Does not support
+	 * returning footer headers. Shouldn't be too difficult to support it though.
+	 *
+	 * @todo Add support for footer chunked headers.
+	 * @access public
+	 * @since 2.7.0
+	 * @static
+	 *
+	 * @param string $body Body content
+	 * @return string Chunked decoded body on success or raw body on failure.
+	 */
+	function chunkTransferDecode($body) {
+		$body = str_replace(array("\r\n", "\r"), "\n", $body);
+		// The body is not chunked encoding or is malformed.
+		if ( ! preg_match( '/^[0-9a-f]+(\s|\n)+/mi', trim($body) ) )
+			return $body;
+
+		$parsedBody = '';
+		//$parsedHeaders = array(); Unsupported
+
+		while ( true ) {
+			$hasChunk = (bool) preg_match( '/^([0-9a-f]+)(\s|\n)+/mi', $body, $match );
+
+			if ( $hasChunk ) {
+				if ( empty( $match[1] ) )
+					return $body;
+
+				$length = hexdec( $match[1] );
+				$chunkLength = strlen( $match[0] );
+
+				$strBody = substr($body, $chunkLength, $length);
+				$parsedBody .= $strBody;
+
+				$body = ltrim(str_replace(array($match[0], $strBody), '', $body), "\n");
+
+				if ( "0" == trim($body) )
+					return $parsedBody; // Ignore footer headers.
+			} else {
+				return $body;
+			}
+		}
+	}
+
+	/**
+	 * Block requests through the proxy.
+	 *
+	 * Those who are behind a proxy and want to prevent access to certain hosts may do so. This will
+	 * prevent plugins from working and core functionality, if you don't include api.wordpress.org.
+	 *
+	 * You block external URL requests by defining WP_HTTP_BLOCK_EXTERNAL as true in your wp-config.php
+	 * file and this will only allow localhost and your blog to make requests. The constant
+	 * WP_ACCESSIBLE_HOSTS will allow additional hosts to go through for requests. The format of the
+	 * WP_ACCESSIBLE_HOSTS constant is a comma separated list of hostnames to allow, wildcard domains
+	 * are supported, eg *.wordpress.org will allow for all subdomains of wordpress.org to be contacted.
+	 *
+	 * @since 2.8.0
+	 * @link http://core.trac.wordpress.org/ticket/8927 Allow preventing external requests.
+	 * @link http://core.trac.wordpress.org/ticket/14636 Allow wildcard domains in WP_ACCESSIBLE_HOSTS
+	 *
+	 * @param string $uri URI of url.
+	 * @return bool True to block, false to allow.
+	 */
+	function block_request($uri) {
+		// We don't need to block requests, because nothing is blocked.
+		if ( ! defined( 'WP_HTTP_BLOCK_EXTERNAL' ) || ! WP_HTTP_BLOCK_EXTERNAL )
+			return false;
+
+		// parse_url() only handles http, https type URLs, and will emit E_WARNING on failure.
+		// This will be displayed on blogs, which is not reasonable.
+		$check = @parse_url($uri);
+
+		/* Malformed URL, can not process, but this could mean ssl, so let through anyway.
+		 *
+		 * This isn't very security sound. There are instances where a hacker might attempt
+		 * to bypass the proxy and this check. However, the reason for this behavior is that
+		 * WordPress does not do any checking currently for non-proxy requests, so it is keeps with
+		 * the default unsecure nature of the HTTP request.
+		 */
+		if ( $check === false )
+			return false;
+
+		$home = parse_url( get_option('siteurl') );
+
+		// Don't block requests back to ourselves by default
+		if ( $check['host'] == 'localhost' || $check['host'] == $home['host'] )
+			return apply_filters('block_local_requests', false);
+
+		if ( !defined('WP_ACCESSIBLE_HOSTS') )
+			return true;
+
+		static $accessible_hosts;
+		static $wildcard_regex = false;
+		if ( null == $accessible_hosts ) {
+			$accessible_hosts = preg_split('|,\s*|', WP_ACCESSIBLE_HOSTS);
+
+			if ( false !== strpos(WP_ACCESSIBLE_HOSTS, '*') ) {
+				$wildcard_regex = array();
+				foreach ( $accessible_hosts as $host )
+					$wildcard_regex[] = str_replace('\*', '[\w.]+?', preg_quote($host, '/'));
+				$wildcard_regex = '/^(' . implode('|', $wildcard_regex) . ')$/i';
+			}
+		}
+
+		if ( !empty($wildcard_regex) )
+			return !preg_match($wildcard_regex, $check['host']);
+		else
+			return !in_array( $check['host'], $accessible_hosts ); //Inverse logic, If its in the array, then we can't access it.
+
+	}
+
+	static function make_absolute_url( $maybe_relative_path, $url ) {
+		if ( empty( $url ) )
+			return $maybe_relative_path;
+
+		// Check for a scheme
+		if ( false !== strpos( $maybe_relative_path, '://' ) )
+			return $maybe_relative_path;
+
+		if ( ! $url_parts = @parse_url( $url ) )
+			return $maybe_relative_path;
+
+		if ( ! $relative_url_parts = @parse_url( $maybe_relative_path ) )
+			return $maybe_relative_path;
+
+		$absolute_path = $url_parts['scheme'] . '://' . $url_parts['host'];
+		if ( isset( $url_parts['port'] ) )
+			$absolute_path .= ':' . $url_parts['port'];
+
+		// Start off with the Absolute URL path
+		$path = ! empty( $url_parts['path'] ) ? $url_parts['path'] : '/';
+
+		// If the it's a root-relative path, then great
+		if ( ! empty( $relative_url_parts['path'] ) && '/' == $relative_url_parts['path'][0] ) {
+			$path = $relative_url_parts['path'];
+
+		// Else it's a relative path
+		} elseif ( ! empty( $relative_url_parts['path'] ) ) {
+			// Strip off any file components from the absolute path
+			$path = substr( $path, 0, strrpos( $path, '/' ) + 1 );
+
+			// Build the new path
+			$path .= $relative_url_parts['path'];
+
+			// Strip all /path/../ out of the path
+			while ( strpos( $path, '../' ) > 1 ) {
+				$path = preg_replace( '![^/]+/\.\./!', '', $path );
+			}
+
+			// Strip any final leading ../ from the path
+			$path = preg_replace( '!^/(\.\./)+!', '', $path );
+		}
+
+		// Add the Query string
+		if ( ! empty( $relative_url_parts['query'] ) )
+			$path .= '?' . $relative_url_parts['query'];
+
+		return $absolute_path . '/' . ltrim( $path, '/' );
+	}
+}
+
+/**
+ * HTTP request method uses fsockopen function to retrieve the url.
+ *
+ * This would be the preferred method, but the fsockopen implementation has the most overhead of all
+ * the HTTP transport implementations.
+ *
+ * @package WordPress
+ * @subpackage HTTP
+ * @since 2.7.0
+ */
+class WP_Http_Fsockopen {
+	/**
+	 * Send a HTTP request to a URI using fsockopen().
+	 *
+	 * Does not support non-blocking mode.
+	 *
+	 * @see WP_Http::request For default options descriptions.
+	 *
+	 * @since 2.7
+	 * @access public
+	 * @param string $url URI resource.
+	 * @param str|array $args Optional. Override the defaults.
+	 * @return array 'headers', 'body', 'response', 'cookies' and 'filename' keys.
+	 */
+	function request($url, $args = array()) {
+		$defaults = array(
+			'method' => 'GET', 'timeout' => 5,
+			'redirection' => 5, 'httpversion' => '1.0',
+			'blocking' => true,
+			'headers' => array(), 'body' => null, 'cookies' => array()
+		);
+
+		$r = wp_parse_args( $args, $defaults );
+
+		if ( isset($r['headers']['User-Agent']) ) {
+			$r['user-agent'] = $r['headers']['User-Agent'];
+			unset($r['headers']['User-Agent']);
+		} else if ( isset($r['headers']['user-agent']) ) {
+			$r['user-agent'] = $r['headers']['user-agent'];
+			unset($r['headers']['user-agent']);
+		}
+
+		// Construct Cookie: header if any cookies are set
+		WP_Http::buildCookieHeader( $r );
+
+		$iError = null; // Store error number
+		$strError = null; // Store error string
+
+		$arrURL = parse_url($url);
+
+		$fsockopen_host = $arrURL['host'];
+
+		$secure_transport = false;
+
+		if ( ! isset( $arrURL['port'] ) ) {
+			if ( ( $arrURL['scheme'] == 'ssl' || $arrURL['scheme'] == 'https' ) && extension_loaded('openssl') ) {
+				$fsockopen_host = "ssl://$fsockopen_host";
+				$arrURL['port'] = 443;
+				$secure_transport = true;
+			} else {
+				$arrURL['port'] = 80;
+			}
+		}
+
+		//fsockopen has issues with 'localhost' with IPv6 with certain versions of PHP, It attempts to connect to ::1,
+		// which fails when the server is not set up for it. For compatibility, always connect to the IPv4 address.
+		if ( 'localhost' == strtolower($fsockopen_host) )
+			$fsockopen_host = '127.0.0.1';
+
+		// There are issues with the HTTPS and SSL protocols that cause errors that can be safely
+		// ignored and should be ignored.
+		if ( true === $secure_transport )
+			$error_reporting = error_reporting(0);
+
+		$startDelay = time();
+
+		$proxy = new WP_HTTP_Proxy();
+
+		if ( !WP_DEBUG ) {
+			if ( $proxy->is_enabled() && $proxy->send_through_proxy( $url ) )
+				$handle = @fsockopen( $proxy->host(), $proxy->port(), $iError, $strError, $r['timeout'] );
+			else
+				$handle = @fsockopen( $fsockopen_host, $arrURL['port'], $iError, $strError, $r['timeout'] );
+		} else {
+			if ( $proxy->is_enabled() && $proxy->send_through_proxy( $url ) )
+				$handle = fsockopen( $proxy->host(), $proxy->port(), $iError, $strError, $r['timeout'] );
+			else
+				$handle = fsockopen( $fsockopen_host, $arrURL['port'], $iError, $strError, $r['timeout'] );
+		}
+
+		$endDelay = time();
+
+		// If the delay is greater than the timeout then fsockopen shouldn't be used, because it will
+		// cause a long delay.
+		$elapseDelay = ($endDelay-$startDelay) > $r['timeout'];
+		if ( true === $elapseDelay )
+			add_option( 'disable_fsockopen', $endDelay, null, true );
+
+		if ( false === $handle )
+			return new WP_Error('http_request_failed', $iError . ': ' . $strError);
+
+		$timeout = (int) floor( $r['timeout'] );
+		$utimeout = $timeout == $r['timeout'] ? 0 : 1000000 * $r['timeout'] % 1000000;
+		stream_set_timeout( $handle, $timeout, $utimeout );
+
+		if ( $proxy->is_enabled() && $proxy->send_through_proxy( $url ) ) //Some proxies require full URL in this field.
+			$requestPath = $url;
+		else
+			$requestPath = $arrURL['path'] . ( isset($arrURL['query']) ? '?' . $arrURL['query'] : '' );
+
+		if ( empty($requestPath) )
+			$requestPath .= '/';
+
+		$strHeaders = strtoupper($r['method']) . ' ' . $requestPath . ' HTTP/' . $r['httpversion'] . "\r\n";
+
+		if ( $proxy->is_enabled() && $proxy->send_through_proxy( $url ) )
+			$strHeaders .= 'Host: ' . $arrURL['host'] . ':' . $arrURL['port'] . "\r\n";
+		else
+			$strHeaders .= 'Host: ' . $arrURL['host'] . "\r\n";
+
+		if ( isset($r['user-agent']) )
+			$strHeaders .= 'User-agent: ' . $r['user-agent'] . "\r\n";
+
+		if ( is_array($r['headers']) ) {
+			foreach ( (array) $r['headers'] as $header => $headerValue )
+				$strHeaders .= $header . ': ' . $headerValue . "\r\n";
+		} else {
+			$strHeaders .= $r['headers'];
+		}
+
+		if ( $proxy->use_authentication() )
+			$strHeaders .= $proxy->authentication_header() . "\r\n";
+
+		$strHeaders .= "\r\n";
+
+		if ( ! is_null($r['body']) )
+			$strHeaders .= $r['body'];
+
+		fwrite($handle, $strHeaders);
+
+		if ( ! $r['blocking'] ) {
+			fclose($handle);
+			return array( 'headers' => array(), 'body' => '', 'response' => array('code' => false, 'message' => false), 'cookies' => array() );
+		}
+
+		$strResponse = '';
+		$bodyStarted = false;
+
+		// If streaming to a file setup the file handle
+		if ( $r['stream'] ) {
+			if ( ! WP_DEBUG )
+				$stream_handle = @fopen( $r['filename'], 'w+' );
+			else
+				$stream_handle = fopen( $r['filename'], 'w+' );
+			if ( ! $stream_handle )
+				return new WP_Error( 'http_request_failed', sprintf( __( 'Could not open handle for fopen() to %s' ), $r['filename'] ) );
+
+			while ( ! feof($handle) ) {
+				$block = fread( $handle, 4096 );
+				if ( $bodyStarted ) {
+					fwrite( $stream_handle, $block );
+				} else {
+					$strResponse .= $block;
+					if ( strpos( $strResponse, "\r\n\r\n" ) ) {
+						$process = WP_Http::processResponse( $strResponse );
+						$bodyStarted = true;
+						fwrite( $stream_handle, $process['body'] );
+						unset( $strResponse );
+						$process['body'] = '';
+					}
+				}
+			}
+
+			fclose( $stream_handle );
+
+		} else {
+			while ( ! feof($handle) )
+				$strResponse .= fread( $handle, 4096 );
+
+			$process = WP_Http::processResponse( $strResponse );
+			unset( $strResponse );
+		}
+
+		fclose( $handle );
+
+		if ( true === $secure_transport )
+			error_reporting($error_reporting);
+
+		$arrHeaders = WP_Http::processHeaders( $process['headers'] );
+
+		// If location is found, then assume redirect and redirect to location.
+		if ( isset($arrHeaders['headers']['location']) && 0 !== $r['_redirection'] ) {
+			if ( $r['redirection']-- > 0 ) {
+				return $this->request( WP_HTTP::make_absolute_url( $arrHeaders['headers']['location'], $url ), $r);
+			} else {
+				return new WP_Error('http_request_failed', __('Too many redirects.'));
+			}
+		}
+
+		// If the body was chunk encoded, then decode it.
+		if ( ! empty( $process['body'] ) && isset( $arrHeaders['headers']['transfer-encoding'] ) && 'chunked' == $arrHeaders['headers']['transfer-encoding'] )
+			$process['body'] = WP_Http::chunkTransferDecode($process['body']);
+
+		if ( true === $r['decompress'] && true === WP_Http_Encoding::should_decode($arrHeaders['headers']) )
+			$process['body'] = WP_Http_Encoding::decompress( $process['body'] );
+
+		return array( 'headers' => $arrHeaders['headers'], 'body' => $process['body'], 'response' => $arrHeaders['response'], 'cookies' => $arrHeaders['cookies'], 'filename' => $r['filename'] );
+	}
+
+	/**
+	 * Whether this class can be used for retrieving an URL.
+	 *
+	 * @since 2.7.0
+	 * @static
+	 * @return boolean False means this class can not be used, true means it can.
+	 */
+	public static function test( $args = array() ) {
+		if ( ! function_exists( 'fsockopen' ) )
+			return false;
+
+		if ( false !== ($option = get_option( 'disable_fsockopen' )) && time()-$option < 43200 ) // 12 hours
+			return false;
+
+		$is_ssl = isset( $args['ssl'] ) && $args['ssl'];
+
+		if ( $is_ssl && ! extension_loaded( 'openssl' ) )
+			return false;
+
+		return apply_filters( 'use_fsockopen_transport', true, $args );
+	}
+}
+
+/**
+ * HTTP request method uses Streams to retrieve the url.
+ *
+ * Requires PHP 5.0+ and uses fopen with stream context. Requires that 'allow_url_fopen' PHP setting
+ * to be enabled.
+ *
+ * Second preferred method for getting the URL, for PHP 5.
+ *
+ * @package WordPress
+ * @subpackage HTTP
+ * @since 2.7.0
+ */
+class WP_Http_Streams {
+	/**
+	 * Send a HTTP request to a URI using streams with fopen().
+	 *
+	 * @access public
+	 * @since 2.7.0
+	 *
+	 * @param string $url
+	 * @param str|array $args Optional. Override the defaults.
+	 * @return array 'headers', 'body', 'response', 'cookies' and 'filename' keys.
+	 */
+	function request($url, $args = array()) {
+		$defaults = array(
+			'method' => 'GET', 'timeout' => 5,
+			'redirection' => 5, 'httpversion' => '1.0',
+			'blocking' => true,
+			'headers' => array(), 'body' => null, 'cookies' => array()
+		);
+
+		$r = wp_parse_args( $args, $defaults );
+
+		if ( isset($r['headers']['User-Agent']) ) {
+			$r['user-agent'] = $r['headers']['User-Agent'];
+			unset($r['headers']['User-Agent']);
+		} else if ( isset($r['headers']['user-agent']) ) {
+			$r['user-agent'] = $r['headers']['user-agent'];
+			unset($r['headers']['user-agent']);
+		}
+
+		// Construct Cookie: header if any cookies are set
+		WP_Http::buildCookieHeader( $r );
+
+		$arrURL = parse_url($url);
+
+		if ( false === $arrURL )
+			return new WP_Error('http_request_failed', sprintf(__('Malformed URL: %s'), $url));
+
+		if ( 'http' != $arrURL['scheme'] && 'https' != $arrURL['scheme'] )
+			$url = preg_replace('|^' . preg_quote($arrURL['scheme'], '|') . '|', 'http', $url);
+
+		// Convert Header array to string.
+		$strHeaders = '';
+		if ( is_array( $r['headers'] ) )
+			foreach ( $r['headers'] as $name => $value )
+				$strHeaders .= "{$name}: $value\r\n";
+		else if ( is_string( $r['headers'] ) )
+			$strHeaders = $r['headers'];
+
+		$is_local = isset($args['local']) && $args['local'];
+		$ssl_verify = isset($args['sslverify']) && $args['sslverify'];
+		if ( $is_local )
+			$ssl_verify = apply_filters('https_local_ssl_verify', $ssl_verify);
+		elseif ( ! $is_local )
+			$ssl_verify = apply_filters('https_ssl_verify', $ssl_verify);
+
+		$arrContext = array('http' =>
+			array(
+				'method' => strtoupper($r['method']),
+				'user_agent' => $r['user-agent'],
+				'max_redirects' => $r['redirection'] + 1, // See #11557
+				'protocol_version' => (float) $r['httpversion'],
+				'header' => $strHeaders,
+				'ignore_errors' => true, // Return non-200 requests.
+				'timeout' => $r['timeout'],
+				'ssl' => array(
+						'verify_peer' => $ssl_verify,
+						'verify_host' => $ssl_verify
+				)
+			)
+		);
+
+		$proxy = new WP_HTTP_Proxy();
+
+		if ( $proxy->is_enabled() && $proxy->send_through_proxy( $url ) ) {
+			$arrContext['http']['proxy'] = 'tcp://' . $proxy->host() . ':' . $proxy->port();
+			$arrContext['http']['request_fulluri'] = true;
+
+			// We only support Basic authentication so this will only work if that is what your proxy supports.
+			if ( $proxy->use_authentication() )
+				$arrContext['http']['header'] .= $proxy->authentication_header() . "\r\n";
+		}
+
+		if ( ! empty($r['body'] ) )
+			$arrContext['http']['content'] = $r['body'];
+
+		$context = stream_context_create($arrContext);
+
+		if ( !WP_DEBUG )
+			$handle = @fopen($url, 'r', false, $context);
+		else
+			$handle = fopen($url, 'r', false, $context);
+
+		if ( ! $handle )
+			return new WP_Error('http_request_failed', sprintf(__('Could not open handle for fopen() to %s'), $url));
+
+		$timeout = (int) floor( $r['timeout'] );
+		$utimeout = $timeout == $r['timeout'] ? 0 : 1000000 * $r['timeout'] % 1000000;
+		stream_set_timeout( $handle, $timeout, $utimeout );
+
+		if ( ! $r['blocking'] ) {
+			stream_set_blocking($handle, 0);
+			fclose($handle);
+			return array( 'headers' => array(), 'body' => '', 'response' => array('code' => false, 'message' => false), 'cookies' => array() );
+		}
+
+		if ( $r['stream'] ) {
+			if ( ! WP_DEBUG )
+				$stream_handle = @fopen( $r['filename'], 'w+' );
+			else
+				$stream_handle = fopen( $r['filename'], 'w+' );
+
+			if ( ! $stream_handle )
+				return new WP_Error( 'http_request_failed', sprintf( __( 'Could not open handle for fopen() to %s' ), $r['filename'] ) );
+
+			stream_copy_to_stream( $handle, $stream_handle );
+
+			fclose( $stream_handle );
+			$strResponse = '';
+		} else {
+			$strResponse = stream_get_contents( $handle );
+		}
+
+		$meta = stream_get_meta_data( $handle );
+
+		fclose( $handle );
+
+		$processedHeaders = array();
+		if ( isset( $meta['wrapper_data']['headers'] ) )
+			$processedHeaders = WP_Http::processHeaders($meta['wrapper_data']['headers']);
+		else
+			$processedHeaders = WP_Http::processHeaders($meta['wrapper_data']);
+
+		// Streams does not provide an error code which we can use to see why the request stream stopped.
+		// We can however test to see if a location header is present and return based on that.
+		if ( isset($processedHeaders['headers']['location']) && 0 !== $args['_redirection'] )
+			return new WP_Error('http_request_failed', __('Too many redirects.'));
+
+		if ( ! empty( $strResponse ) && isset( $processedHeaders['headers']['transfer-encoding'] ) && 'chunked' == $processedHeaders['headers']['transfer-encoding'] )
+			$strResponse = WP_Http::chunkTransferDecode($strResponse);
+
+		if ( true === $r['decompress'] && true === WP_Http_Encoding::should_decode($processedHeaders['headers']) )
+			$strResponse = WP_Http_Encoding::decompress( $strResponse );
+
+		return array( 'headers' => $processedHeaders['headers'], 'body' => $strResponse, 'response' => $processedHeaders['response'], 'cookies' => $processedHeaders['cookies'], 'filename' => $r['filename'] );
+	}
+
+	/**
+	 * Whether this class can be used for retrieving an URL.
+	 *
+	 * @static
+	 * @access public
+	 * @since 2.7.0
+	 *
+	 * @return boolean False means this class can not be used, true means it can.
+	 */
+	public static function test( $args = array() ) {
+		if ( ! function_exists( 'fopen' ) )
+			return false;
+
+		if ( ! function_exists( 'ini_get' ) || true != ini_get( 'allow_url_fopen' ) )
+			return false;
+
+		$is_ssl = isset( $args['ssl'] ) && $args['ssl'];
+
+		if ( $is_ssl && ! extension_loaded( 'openssl' ) )
+			return false;
+
+		return apply_filters( 'use_streams_transport', true, $args );
+	}
+}
+
+/**
+ * HTTP request method uses Curl extension to retrieve the url.
+ *
+ * Requires the Curl extension to be installed.
+ *
+ * @package WordPress
+ * @subpackage HTTP
+ * @since 2.7
+ */
+class WP_Http_Curl {
+
+	/**
+	 * Temporary header storage for use with streaming to a file.
+	 *
+	 * @since 3.2.0
+	 * @access private
+	 * @var string
+	 */
+	private $headers = '';
+
+	/**
+	 * Send a HTTP request to a URI using cURL extension.
+	 *
+	 * @access public
+	 * @since 2.7.0
+	 *
+	 * @param string $url
+	 * @param str|array $args Optional. Override the defaults.
+	 * @return array 'headers', 'body', 'response', 'cookies' and 'filename' keys.
+	 */
+	function request($url, $args = array()) {
+		$defaults = array(
+			'method' => 'GET', 'timeout' => 5,
+			'redirection' => 5, 'httpversion' => '1.0',
+			'blocking' => true,
+			'headers' => array(), 'body' => null, 'cookies' => array()
+		);
+
+		$r = wp_parse_args( $args, $defaults );
+
+		if ( isset($r['headers']['User-Agent']) ) {
+			$r['user-agent'] = $r['headers']['User-Agent'];
+			unset($r['headers']['User-Agent']);
+		} else if ( isset($r['headers']['user-agent']) ) {
+			$r['user-agent'] = $r['headers']['user-agent'];
+			unset($r['headers']['user-agent']);
+		}
+
+		// Construct Cookie: header if any cookies are set.
+		WP_Http::buildCookieHeader( $r );
+
+		$handle = curl_init();
+
+		// cURL offers really easy proxy support.
+		$proxy = new WP_HTTP_Proxy();
+
+		if ( $proxy->is_enabled() && $proxy->send_through_proxy( $url ) ) {
+
+			curl_setopt( $handle, CURLOPT_PROXYTYPE, CURLPROXY_HTTP );
+			curl_setopt( $handle, CURLOPT_PROXY, $proxy->host() );
+			curl_setopt( $handle, CURLOPT_PROXYPORT, $proxy->port() );
+
+			if ( $proxy->use_authentication() ) {
+				curl_setopt( $handle, CURLOPT_PROXYAUTH, CURLAUTH_ANY );
+				curl_setopt( $handle, CURLOPT_PROXYUSERPWD, $proxy->authentication() );
+			}
+		}
+
+		$is_local = isset($r['local']) && $r['local'];
+		$ssl_verify = isset($r['sslverify']) && $r['sslverify'];
+		if ( $is_local )
+			$ssl_verify = apply_filters('https_local_ssl_verify', $ssl_verify);
+		elseif ( ! $is_local )
+			$ssl_verify = apply_filters('https_ssl_verify', $ssl_verify);
+
+		// CURLOPT_TIMEOUT and CURLOPT_CONNECTTIMEOUT expect integers. Have to use ceil since
+		// a value of 0 will allow an unlimited timeout.
+		$timeout = (int) ceil( $r['timeout'] );
+		curl_setopt( $handle, CURLOPT_CONNECTTIMEOUT, $timeout );
+		curl_setopt( $handle, CURLOPT_TIMEOUT, $timeout );
+
+		curl_setopt( $handle, CURLOPT_URL, $url);
+		curl_setopt( $handle, CURLOPT_RETURNTRANSFER, true );
+		curl_setopt( $handle, CURLOPT_SSL_VERIFYHOST, ( $ssl_verify === true ) ? 2 : false );
+		curl_setopt( $handle, CURLOPT_SSL_VERIFYPEER, $ssl_verify );
+		curl_setopt( $handle, CURLOPT_USERAGENT, $r['user-agent'] );
+		// The option doesn't work with safe mode or when open_basedir is set, and there's a
+		// bug #17490 with redirected POST requests, so handle redirections outside Curl.
+		curl_setopt( $handle, CURLOPT_FOLLOWLOCATION, false );
+
+		switch ( $r['method'] ) {
+			case 'HEAD':
+				curl_setopt( $handle, CURLOPT_NOBODY, true );
+				break;
+			case 'POST':
+				curl_setopt( $handle, CURLOPT_POST, true );
+				curl_setopt( $handle, CURLOPT_POSTFIELDS, $r['body'] );
+				break;
+			case 'PUT':
+				curl_setopt( $handle, CURLOPT_CUSTOMREQUEST, 'PUT' );
+				curl_setopt( $handle, CURLOPT_POSTFIELDS, $r['body'] );
+				break;
+			default:
+				curl_setopt( $handle, CURLOPT_CUSTOMREQUEST, $r['method'] );
+				if ( ! empty( $r['body'] ) )
+					curl_setopt( $handle, CURLOPT_POSTFIELDS, $r['body'] );
+				break;
+		}
+
+		if ( true === $r['blocking'] )
+			curl_setopt( $handle, CURLOPT_HEADERFUNCTION, array( &$this, 'stream_headers' ) );
+
+		curl_setopt( $handle, CURLOPT_HEADER, false );
+
+		// If streaming to a file open a file handle, and setup our curl streaming handler
+		if ( $r['stream'] ) {
+			if ( ! WP_DEBUG )
+				$stream_handle = @fopen( $r['filename'], 'w+' );
+			else
+				$stream_handle = fopen( $r['filename'], 'w+' );
+			if ( ! $stream_handle )
+				return new WP_Error( 'http_request_failed', sprintf( __( 'Could not open handle for fopen() to %s' ), $r['filename'] ) );
+			curl_setopt( $handle, CURLOPT_FILE, $stream_handle );
+		}
+
+		if ( !empty( $r['headers'] ) ) {
+			// cURL expects full header strings in each element
+			$headers = array();
+			foreach ( $r['headers'] as $name => $value ) {
+				$headers[] = "{$name}: $value";
+			}
+			curl_setopt( $handle, CURLOPT_HTTPHEADER, $headers );
+		}
+
+		if ( $r['httpversion'] == '1.0' )
+			curl_setopt( $handle, CURLOPT_HTTP_VERSION, CURL_HTTP_VERSION_1_0 );
+		else
+			curl_setopt( $handle, CURLOPT_HTTP_VERSION, CURL_HTTP_VERSION_1_1 );
+
+		// Cookies are not handled by the HTTP API currently. Allow for plugin authors to handle it
+		// themselves... Although, it is somewhat pointless without some reference.
+		do_action_ref_array( 'http_api_curl', array(&$handle) );
+
+		// We don't need to return the body, so don't. Just execute request and return.
+		if ( ! $r['blocking'] ) {
+			curl_exec( $handle );
+			curl_close( $handle );
+			return array( 'headers' => array(), 'body' => '', 'response' => array('code' => false, 'message' => false), 'cookies' => array() );
+		}
+
+		$theResponse = curl_exec( $handle );
+		$theBody = '';
+		$theHeaders = WP_Http::processHeaders( $this->headers );
+
+		if ( strlen($theResponse) > 0 && ! is_bool( $theResponse ) ) // is_bool: when using $args['stream'], curl_exec will return (bool)true
+			$theBody = $theResponse;
+
+		// If no response
+		if ( 0 == strlen( $theResponse ) && empty( $theHeaders['headers'] ) ) {
+			if ( $curl_error = curl_error( $handle ) )
+				return new WP_Error( 'http_request_failed', $curl_error );
+			if ( in_array( curl_getinfo( $handle, CURLINFO_HTTP_CODE ), array( 301, 302 ) ) )
+				return new WP_Error( 'http_request_failed', __( 'Too many redirects.' ) );
+		}
+
+		$this->headers = '';
+
+		$response = array();
+		$response['code'] = curl_getinfo( $handle, CURLINFO_HTTP_CODE );
+		$response['message'] = get_status_header_desc($response['code']);
+
+		curl_close( $handle );
+
+		if ( $r['stream'] )
+			fclose( $stream_handle );
+
+		// See #11305 - When running under safe mode, redirection is disabled above. Handle it manually.
+		if ( ! empty( $theHeaders['headers']['location'] ) && 0 !== $r['_redirection'] ) { // _redirection: The requested number of redirections
+			if ( $r['redirection']-- > 0 ) {
+				return $this->request( WP_HTTP::make_absolute_url( $theHeaders['headers']['location'], $url ), $r );
+			} else {
+				return new WP_Error( 'http_request_failed', __( 'Too many redirects.' ) );
+			}
+		}
+
+		if ( true === $r['decompress'] && true === WP_Http_Encoding::should_decode($theHeaders['headers']) )
+			$theBody = WP_Http_Encoding::decompress( $theBody );
+
+		return array( 'headers' => $theHeaders['headers'], 'body' => $theBody, 'response' => $response, 'cookies' => $theHeaders['cookies'], 'filename' => $r['filename'] );
+	}
+
+	/**
+	 * Grab the headers of the cURL request
+	 *
+	 * Each header is sent individually to this callback, so we append to the $header property for temporary storage
+	 *
+	 * @since 3.2.0
+	 * @access private
+	 * @return int
+	 */
+	private function stream_headers( $handle, $headers ) {
+		$this->headers .= $headers;
+		return strlen( $headers );
+	}
+
+	/**
+	 * Whether this class can be used for retrieving an URL.
+	 *
+	 * @static
+	 * @since 2.7.0
+	 *
+	 * @return boolean False means this class can not be used, true means it can.
+	 */
+	public static function test( $args = array() ) {
+		if ( ! function_exists( 'curl_init' ) || ! function_exists( 'curl_exec' ) )
+			return false;
+
+		$is_ssl = isset( $args['ssl'] ) && $args['ssl'];
+
+		if ( $is_ssl ) {
+			$curl_version = curl_version();
+			if ( ! (CURL_VERSION_SSL & $curl_version['features']) ) // Does this cURL version support SSL requests?
+				return false;
+		}
+
+		return apply_filters( 'use_curl_transport', true, $args );
+	}
+}
+
+/**
+ * Adds Proxy support to the WordPress HTTP API.
+ *
+ * There are caveats to proxy support. It requires that defines be made in the wp-config.php file to
+ * enable proxy support. There are also a few filters that plugins can hook into for some of the
+ * constants.
+ *
+ * Please note that only BASIC authentication is supported by most transports.
+ * cURL MAY support more methods (such as NTLM authentication) depending on your environment.
+ *
+ * The constants are as follows:
+ * <ol>
+ * <li>WP_PROXY_HOST - Enable proxy support and host for connecting.</li>
+ * <li>WP_PROXY_PORT - Proxy port for connection. No default, must be defined.</li>
+ * <li>WP_PROXY_USERNAME - Proxy username, if it requires authentication.</li>
+ * <li>WP_PROXY_PASSWORD - Proxy password, if it requires authentication.</li>
+ * <li>WP_PROXY_BYPASS_HOSTS - Will prevent the hosts in this list from going through the proxy.
+ * You do not need to have localhost and the blog host in this list, because they will not be passed
+ * through the proxy. The list should be presented in a comma separated list, wildcards using * are supported, eg. *.wordpress.org</li>
+ * </ol>
+ *
+ * An example can be as seen below.
+ * <code>
+ * define('WP_PROXY_HOST', '192.168.84.101');
+ * define('WP_PROXY_PORT', '8080');
+ * define('WP_PROXY_BYPASS_HOSTS', 'localhost, www.example.com, *.wordpress.org');
+ * </code>
+ *
+ * @link http://core.trac.wordpress.org/ticket/4011 Proxy support ticket in WordPress.
+ * @link http://core.trac.wordpress.org/ticket/14636 Allow wildcard domains in WP_PROXY_BYPASS_HOSTS
+ * @since 2.8
+ */
+class WP_HTTP_Proxy {
+
+	/**
+	 * Whether proxy connection should be used.
+	 *
+	 * @since 2.8
+	 * @use WP_PROXY_HOST
+	 * @use WP_PROXY_PORT
+	 *
+	 * @return bool
+	 */
+	function is_enabled() {
+		return defined('WP_PROXY_HOST') && defined('WP_PROXY_PORT');
+	}
+
+	/**
+	 * Whether authentication should be used.
+	 *
+	 * @since 2.8
+	 * @use WP_PROXY_USERNAME
+	 * @use WP_PROXY_PASSWORD
+	 *
+	 * @return bool
+	 */
+	function use_authentication() {
+		return defined('WP_PROXY_USERNAME') && defined('WP_PROXY_PASSWORD');
+	}
+
+	/**
+	 * Retrieve the host for the proxy server.
+	 *
+	 * @since 2.8
+	 *
+	 * @return string
+	 */
+	function host() {
+		if ( defined('WP_PROXY_HOST') )
+			return WP_PROXY_HOST;
+
+		return '';
+	}
+
+	/**
+	 * Retrieve the port for the proxy server.
+	 *
+	 * @since 2.8
+	 *
+	 * @return string
+	 */
+	function port() {
+		if ( defined('WP_PROXY_PORT') )
+			return WP_PROXY_PORT;
+
+		return '';
+	}
+
+	/**
+	 * Retrieve the username for proxy authentication.
+	 *
+	 * @since 2.8
+	 *
+	 * @return string
+	 */
+	function username() {
+		if ( defined('WP_PROXY_USERNAME') )
+			return WP_PROXY_USERNAME;
+
+		return '';
+	}
+
+	/**
+	 * Retrieve the password for proxy authentication.
+	 *
+	 * @since 2.8
+	 *
+	 * @return string
+	 */
+	function password() {
+		if ( defined('WP_PROXY_PASSWORD') )
+			return WP_PROXY_PASSWORD;
+
+		return '';
+	}
+
+	/**
+	 * Retrieve authentication string for proxy authentication.
+	 *
+	 * @since 2.8
+	 *
+	 * @return string
+	 */
+	function authentication() {
+		return $this->username() . ':' . $this->password();
+	}
+
+	/**
+	 * Retrieve header string for proxy authentication.
+	 *
+	 * @since 2.8
+	 *
+	 * @return string
+	 */
+	function authentication_header() {
+		return 'Proxy-Authorization: Basic ' . base64_encode( $this->authentication() );
+	}
+
+	/**
+	 * Whether URL should be sent through the proxy server.
+	 *
+	 * We want to keep localhost and the blog URL from being sent through the proxy server, because
+	 * some proxies can not handle this. We also have the constant available for defining other
+	 * hosts that won't be sent through the proxy.
+	 *
+	 * @uses WP_PROXY_BYPASS_HOSTS
+	 * @since 2.8.0
+	 *
+	 * @param string $uri URI to check.
+	 * @return bool True, to send through the proxy and false if, the proxy should not be used.
+	 */
+	function send_through_proxy( $uri ) {
+		// parse_url() only handles http, https type URLs, and will emit E_WARNING on failure.
+		// This will be displayed on blogs, which is not reasonable.
+		$check = @parse_url($uri);
+
+		// Malformed URL, can not process, but this could mean ssl, so let through anyway.
+		if ( $check === false )
+			return true;
+
+		$home = parse_url( get_option('siteurl') );
+
+		if ( $check['host'] == 'localhost' || $check['host'] == $home['host'] )
+			return false;
+
+		if ( !defined('WP_PROXY_BYPASS_HOSTS') )
+			return true;
+
+		static $bypass_hosts;
+		static $wildcard_regex = false;
+		if ( null == $bypass_hosts ) {
+			$bypass_hosts = preg_split('|,\s*|', WP_PROXY_BYPASS_HOSTS);
+
+			if ( false !== strpos(WP_PROXY_BYPASS_HOSTS, '*') ) {
+				$wildcard_regex = array();
+				foreach ( $bypass_hosts as $host )
+					$wildcard_regex[] = str_replace('\*', '[\w.]+?', preg_quote($host, '/'));
+				$wildcard_regex = '/^(' . implode('|', $wildcard_regex) . ')$/i';
+			}
+		}
+
+		if ( !empty($wildcard_regex) )
+			return !preg_match($wildcard_regex, $check['host']);
+		else
+			return !in_array( $check['host'], $bypass_hosts );
+	}
+}
+/**
+ * Internal representation of a single cookie.
+ *
+ * Returned cookies are represented using this class, and when cookies are set, if they are not
+ * already a WP_Http_Cookie() object, then they are turned into one.
+ *
+ * @todo The WordPress convention is to use underscores instead of camelCase for function and method
+ * names. Need to switch to use underscores instead for the methods.
+ *
+ * @package WordPress
+ * @subpackage HTTP
+ * @since 2.8.0
+ */
+class WP_Http_Cookie {
+
+	/**
+	 * Cookie name.
+	 *
+	 * @since 2.8.0
+	 * @var string
+	 */
+	var $name;
+
+	/**
+	 * Cookie value.
+	 *
+	 * @since 2.8.0
+	 * @var string
+	 */
+	var $value;
+
+	/**
+	 * When the cookie expires.
+	 *
+	 * @since 2.8.0
+	 * @var string
+	 */
+	var $expires;
+
+	/**
+	 * Cookie URL path.
+	 *
+	 * @since 2.8.0
+	 * @var string
+	 */
+	var $path;
+
+	/**
+	 * Cookie Domain.
+	 *
+	 * @since 2.8.0
+	 * @var string
+	 */
+	var $domain;
+
+	/**
+	 * Sets up this cookie object.
+	 *
+	 * The parameter $data should be either an associative array containing the indices names below
+	 * or a header string detailing it.
+	 *
+	 * If it's an array, it should include the following elements:
+	 * <ol>
+	 * <li>Name</li>
+	 * <li>Value - should NOT be urlencoded already.</li>
+	 * <li>Expires - (optional) String or int (UNIX timestamp).</li>
+	 * <li>Path (optional)</li>
+	 * <li>Domain (optional)</li>
+	 * </ol>
+	 *
+	 * @access public
+	 * @since 2.8.0
+	 *
+	 * @param string|array $data Raw cookie data.
+	 */
+	function __construct( $data ) {
+		if ( is_string( $data ) ) {
+			// Assume it's a header string direct from a previous request
+			$pairs = explode( ';', $data );
+
+			// Special handling for first pair; name=value. Also be careful of "=" in value
+			$name  = trim( substr( $pairs[0], 0, strpos( $pairs[0], '=' ) ) );
+			$value = substr( $pairs[0], strpos( $pairs[0], '=' ) + 1 );
+			$this->name  = $name;
+			$this->value = urldecode( $value );
+			array_shift( $pairs ); //Removes name=value from items.
+
+			// Set everything else as a property
+			foreach ( $pairs as $pair ) {
+				$pair = rtrim($pair);
+				if ( empty($pair) ) //Handles the cookie ending in ; which results in a empty final pair
+					continue;
+
+				list( $key, $val ) = strpos( $pair, '=' ) ? explode( '=', $pair ) : array( $pair, '' );
+				$key = strtolower( trim( $key ) );
+				if ( 'expires' == $key )
+					$val = strtotime( $val );
+				$this->$key = $val;
+			}
+		} else {
+			if ( !isset( $data['name'] ) )
+				return false;
+
+			// Set properties based directly on parameters
+			$this->name   = $data['name'];
+			$this->value  = isset( $data['value'] ) ? $data['value'] : '';
+			$this->path   = isset( $data['path'] ) ? $data['path'] : '';
+			$this->domain = isset( $data['domain'] ) ? $data['domain'] : '';
+
+			if ( isset( $data['expires'] ) )
+				$this->expires = is_int( $data['expires'] ) ? $data['expires'] : strtotime( $data['expires'] );
+			else
+				$this->expires = null;
+		}
+	}
+
+	/**
+	 * Confirms that it's OK to send this cookie to the URL checked against.
+	 *
+	 * Decision is based on RFC 2109/2965, so look there for details on validity.
+	 *
+	 * @access public
+	 * @since 2.8.0
+	 *
+	 * @param string $url URL you intend to send this cookie to
+	 * @return boolean true if allowed, false otherwise.
+	 */
+	function test( $url ) {
+		// Expires - if expired then nothing else matters
+		if ( time() > $this->expires )
+			return false;
+
+		// Get details on the URL we're thinking about sending to
+		$url = parse_url( $url );
+		$url['port'] = isset( $url['port'] ) ? $url['port'] : 80;
+		$url['path'] = isset( $url['path'] ) ? $url['path'] : '/';
+
+		// Values to use for comparison against the URL
+		$path   = isset( $this->path )   ? $this->path   : '/';
+		$port   = isset( $this->port )   ? $this->port   : 80;
+		$domain = isset( $this->domain ) ? strtolower( $this->domain ) : strtolower( $url['host'] );
+		if ( false === stripos( $domain, '.' ) )
+			$domain .= '.local';
+
+		// Host - very basic check that the request URL ends with the domain restriction (minus leading dot)
+		$domain = substr( $domain, 0, 1 ) == '.' ? substr( $domain, 1 ) : $domain;
+		if ( substr( $url['host'], -strlen( $domain ) ) != $domain )
+			return false;
+
+		// Port - supports "port-lists" in the format: "80,8000,8080"
+		if ( !in_array( $url['port'], explode( ',', $port) ) )
+			return false;
+
+		// Path - request path must start with path restriction
+		if ( substr( $url['path'], 0, strlen( $path ) ) != $path )
+			return false;
+
+		return true;
+	}
+
+	/**
+	 * Convert cookie name and value back to header string.
+	 *
+	 * @access public
+	 * @since 2.8.0
+	 *
+	 * @return string Header encoded cookie name and value.
+	 */
+	function getHeaderValue() {
+		if ( empty( $this->name ) || empty( $this->value ) )
+			return '';
+
+		return $this->name . '=' . apply_filters( 'wp_http_cookie_value', $this->value, $this->name );
+	}
+
+	/**
+	 * Retrieve cookie header for usage in the rest of the WordPress HTTP API.
+	 *
+	 * @access public
+	 * @since 2.8.0
+	 *
+	 * @return string
+	 */
+	function getFullHeader() {
+		return 'Cookie: ' . $this->getHeaderValue();
+	}
+}
+
+/**
+ * Implementation for deflate and gzip transfer encodings.
+ *
+ * Includes RFC 1950, RFC 1951, and RFC 1952.
+ *
+ * @since 2.8
+ * @package WordPress
+ * @subpackage HTTP
+ */
+class WP_Http_Encoding {
+
+	/**
+	 * Compress raw string using the deflate format.
+	 *
+	 * Supports the RFC 1951 standard.
+	 *
+	 * @since 2.8
+	 *
+	 * @param string $raw String to compress.
+	 * @param int $level Optional, default is 9. Compression level, 9 is highest.
+	 * @param string $supports Optional, not used. When implemented it will choose the right compression based on what the server supports.
+	 * @return string|bool False on failure.
+	 */
+	public static function compress( $raw, $level = 9, $supports = null ) {
+		return gzdeflate( $raw, $level );
+	}
+
+	/**
+	 * Decompression of deflated string.
+	 *
+	 * Will attempt to decompress using the RFC 1950 standard, and if that fails
+	 * then the RFC 1951 standard deflate will be attempted. Finally, the RFC
+	 * 1952 standard gzip decode will be attempted. If all fail, then the
+	 * original compressed string will be returned.
+	 *
+	 * @since 2.8
+	 *
+	 * @param string $compressed String to decompress.
+	 * @param int $length The optional length of the compressed data.
+	 * @return string|bool False on failure.
+	 */
+	public static function decompress( $compressed, $length = null ) {
+
+		if ( empty($compressed) )
+			return $compressed;
+
+		if ( false !== ( $decompressed = @gzinflate( $compressed ) ) )
+			return $decompressed;
+
+		if ( false !== ( $decompressed = WP_Http_Encoding::compatible_gzinflate( $compressed ) ) )
+			return $decompressed;
+
+		if ( false !== ( $decompressed = @gzuncompress( $compressed ) ) )
+			return $decompressed;
+
+		if ( function_exists('gzdecode') ) {
+			$decompressed = @gzdecode( $compressed );
+
+			if ( false !== $decompressed )
+				return $decompressed;
+		}
+
+		return $compressed;
+	}
+
+	/**
+	 * Decompression of deflated string while staying compatible with the majority of servers.
+	 *
+	 * Certain Servers will return deflated data with headers which PHP's gziniflate()
+	 * function cannot handle out of the box. The following function has been created from
+	 * various snippets on the gzinflate() PHP documentation.
+	 *
+	 * Warning: Magic numbers within. Due to the potential different formats that the compressed
+	 * data may be returned in, some "magic offsets" are needed to ensure proper decompression
+	 * takes place. For a simple progmatic way to determine the magic offset in use, see:
+	 * http://core.trac.wordpress.org/ticket/18273
+	 *
+	 * @since 2.8.1
+	 * @link http://core.trac.wordpress.org/ticket/18273
+	 * @link http://au2.php.net/manual/en/function.gzinflate.php#70875
+	 * @link http://au2.php.net/manual/en/function.gzinflate.php#77336
+	 *
+	 * @param string $gzData String to decompress.
+	 * @return string|bool False on failure.
+	 */
+	public static function compatible_gzinflate($gzData) {
+
+		// Compressed data might contain a full header, if so strip it for gzinflate()
+		if ( substr($gzData, 0, 3) == "\x1f\x8b\x08" ) {
+			$i = 10;
+			$flg = ord( substr($gzData, 3, 1) );
+			if ( $flg > 0 ) {
+				if ( $flg & 4 ) {
+					list($xlen) = unpack('v', substr($gzData, $i, 2) );
+					$i = $i + 2 + $xlen;
+				}
+				if ( $flg & 8 )
+					$i = strpos($gzData, "\0", $i) + 1;
+				if ( $flg & 16 )
+					$i = strpos($gzData, "\0", $i) + 1;
+				if ( $flg & 2 )
+					$i = $i + 2;
+			}
+			$decompressed = @gzinflate( substr($gzData, $i, -8) );
+			if ( false !== $decompressed )
+				return $decompressed;
+		}
+
+		// Compressed data from java.util.zip.Deflater amongst others.
+		$decompressed = @gzinflate( substr($gzData, 2) );
+		if ( false !== $decompressed )
+			return $decompressed;
+
+		return false;
+	}
+
+	/**
+	 * What encoding types to accept and their priority values.
+	 *
+	 * @since 2.8
+	 *
+	 * @return string Types of encoding to accept.
+	 */
+	public static function accept_encoding() {
+		$type = array();
+		if ( function_exists( 'gzinflate' ) )
+			$type[] = 'deflate;q=1.0';
+
+		if ( function_exists( 'gzuncompress' ) )
+			$type[] = 'compress;q=0.5';
+
+		if ( function_exists( 'gzdecode' ) )
+			$type[] = 'gzip;q=0.5';
+
+		return implode(', ', $type);
+	}
+
+	/**
+	 * What encoding the content used when it was compressed to send in the headers.
+	 *
+	 * @since 2.8
+	 *
+	 * @return string Content-Encoding string to send in the header.
+	 */
+	public static function content_encoding() {
+		return 'deflate';
+	}
+
+	/**
+	 * Whether the content be decoded based on the headers.
+	 *
+	 * @since 2.8
+	 *
+	 * @param array|string $headers All of the available headers.
+	 * @return bool
+	 */
+	public static function should_decode($headers) {
+		if ( is_array( $headers ) ) {
+			if ( array_key_exists('content-encoding', $headers) && ! empty( $headers['content-encoding'] ) )
+				return true;
+		} else if ( is_string( $headers ) ) {
+			return ( stripos($headers, 'content-encoding:') !== false );
+		}
+
+		return false;
+	}
+
+	/**
+	 * Whether decompression and compression are supported by the PHP version.
+	 *
+	 * Each function is tested instead of checking for the zlib extension, to
+	 * ensure that the functions all exist in the PHP version and aren't
+	 * disabled.
+	 *
+	 * @since 2.8
+	 *
+	 * @return bool
+	 */
+	public static function is_available() {
+		return ( function_exists('gzuncompress') || function_exists('gzdeflate') || function_exists('gzinflate') );
+	}
+}