* (bug 24563) Entries on Special:WhatLinksHere now have a link to their history
[lhc/web/wiklou.git] / includes / HttpFunctions.php
index add4f60..9464895 100644 (file)
@@ -8,14 +8,32 @@
  * @ingroup HTTP
  */
 class Http {
+       static $httpEngine = false;
+
        /**
         * Perform an HTTP request
-        * @param $method string HTTP method. Usually GET/POST
-        * @param $url string Full URL to act on
-        * @param $options options to pass to HttpRequest object
-        * @returns mixed (bool)false on failure or a string on success
+        *
+        * @param $method String: HTTP method. Usually GET/POST
+        * @param $url String: full URL to act on
+        * @param $options Array: options to pass to HttpRequest object.
+        *      Possible keys for the array:
+        *    - timeout             Timeout length in seconds
+        *    - postData            An array of key-value pairs or a url-encoded form data
+        *    - proxy               The proxy to use.
+        *                          Will use $wgHTTPProxy (if set) otherwise.
+        *    - noProxy             Override $wgHTTPProxy (if set) and don't use any proxy at all.
+        *    - sslVerifyHost       (curl only) Verify hostname against certificate
+        *    - sslVerifyCert       (curl only) Verify SSL certificate
+        *    - caInfo              (curl only) Provide CA information
+        *    - maxRedirects        Maximum number of redirects to follow (defaults to 5)
+        *    - followRedirects     Whether to follow redirects (defaults to false). 
+        *                                  Note: this should only be used when the target URL is trusted,
+        *                                  to avoid attacks on intranet services accessible by HTTP.
+        * @return Mixed: (bool)false on failure or a string on success
         */
        public static function request( $method, $url, $options = array() ) {
+               $url = wfExpandUrl( $url );
+               wfDebug( "HTTP: $method: $url\n" );
                $options['method'] = strtoupper( $method );
                if ( !isset( $options['timeout'] ) ) {
                        $options['timeout'] = 'default';
@@ -48,8 +66,9 @@ class Http {
 
        /**
         * Check if the URL can be served by localhost
-        * @param $url string Full url to check
-        * @return bool
+        *
+        * @param $url String: full url to check
+        * @return Boolean
         */
        public static function isLocalURL( $url ) {
                global $wgCommandLineMode, $wgConf;
@@ -82,7 +101,7 @@ class Http {
 
        /**
         * A standard user-agent we can use for external requests.
-        * @returns string
+        * @return String
         */
        public static function userAgent() {
                global $wgVersion;
@@ -91,8 +110,9 @@ class Http {
 
        /**
         * Checks that the given URI is a valid one
+        *
         * @param $uri Mixed: URI to check for validity
-        * @returns bool
+        * @returns Boolean
         */
        public static function isValidURI( $uri ) {
                return preg_match(
@@ -115,27 +135,28 @@ class HttpRequest {
        protected $proxy = null;
        protected $noProxy = false;
        protected $sslVerifyHost = true;
+       protected $sslVerifyCert = true;
        protected $caInfo = null;
        protected $method = "GET";
        protected $reqHeaders = array();
        protected $url;
        protected $parsedUrl;
        protected $callback;
+       protected $maxRedirects = 5;
+       protected $followRedirects = false;
+
+       protected $cookieJar;
+
+       protected $headerList = array();
+       protected $respVersion = "0.9";
+       protected $respStatus = "200 Ok";
+       protected $respHeaders = array();
+
        public $status;
 
        /**
-        * @param $url   string url to use
-        * @param $options array (optional) extra params to pass
-        *                               Possible keys for the array:
-        *                                      method
-        *                                      timeout
-        *                                      targetFilePath
-        *                                      requestKey
-        *                                      postData
-        *                                      proxy
-        *                                      noProxy
-        *                                      sslVerifyHost
-        *                                      caInfo
+        * @param $url String: url to use
+        * @param $options Array: (optional) extra params to pass (see Http::request())
         */
        function __construct( $url, $options = array() ) {
                global $wgHTTPTimeout;
@@ -144,7 +165,7 @@ class HttpRequest {
                $this->parsedUrl = parse_url( $url );
 
                if ( !Http::isValidURI( $this->url ) ) {
-                       $this->status = Status::newFromFatal('http-invalid-url');
+                       $this->status = Status::newFatal('http-invalid-url');
                } else {
                        $this->status = Status::newGood( 100 ); // continue
                }
@@ -155,8 +176,8 @@ class HttpRequest {
                        $this->timeout = $wgHTTPTimeout;
                }
 
-               $members = array( "targetFilePath", "requestKey", "postData",
-                       "proxy", "noProxy", "sslVerifyHost", "caInfo", "method" );
+               $members = array( "postData", "proxy", "noProxy", "sslVerifyHost", "caInfo",
+                                 "method", "followRedirects", "maxRedirects", "sslVerifyCert" );
                foreach ( $members as $o ) {
                        if ( isset($options[$o]) ) {
                                $this->$o = $options[$o];
@@ -168,47 +189,56 @@ class HttpRequest {
         * Generate a new request object
         * @see HttpRequest::__construct
         */
-       public static function factory( $url, $options ) {
-               global $wgHTTPEngine;
-               $engine = $wgHTTPEngine;
-
-               if ( !$wgHTTPEngine ) {
-                       $wgHTTPEngine = function_exists( 'curl_init' ) ? 'curl' : 'php';
-               } elseif ( $wgHTTPEngine == 'curl' && !function_exists( 'curl_init' ) ) {
-                       throw new MWException( __METHOD__.': curl (http://php.net/curl) is not installed, but $wgHTTPEngine is set to "curl"' );
+       public static function factory( $url, $options = null ) {
+               if ( !Http::$httpEngine ) {
+                       Http::$httpEngine = function_exists( 'curl_init' ) ? 'curl' : 'php';
+               } elseif ( Http::$httpEngine == 'curl' && !function_exists( 'curl_init' ) ) {
+                       throw new MWException( __METHOD__.': curl (http://php.net/curl) is not installed, but'.
+                                                                  ' Http::$httpEngine is set to "curl"' );
                }
 
-               switch( $wgHTTPEngine ) {
+               switch( Http::$httpEngine ) {
                case 'curl':
                        return new CurlHttpRequest( $url, $options );
                case 'php':
                        if ( !wfIniGetBool( 'allow_url_fopen' ) ) {
-                               throw new MWException( __METHOD__.': allow_url_fopen needs to be enabled for pure PHP http requests to work. '.
-                                       'If possible, curl should be used instead.  See http://php.net/curl.' );
+                               throw new MWException( __METHOD__.': allow_url_fopen needs to be enabled for pure PHP'.
+                                       ' http requests to work. If possible, curl should be used instead. See http://php.net/curl.' );
                        }
                        return new PhpHttpRequest( $url, $options );
                default:
-                       throw new MWException( __METHOD__.': The setting of $wgHTTPEngine is not valid.' );
+                       throw new MWException( __METHOD__.': The setting of Http::$httpEngine is not valid.' );
                }
        }
 
        /**
         * Get the body, or content, of the response to the request
-        * @return string
+        *
+        * @return String
         */
        public function getContent() {
                return $this->content;
        }
 
+       /**
+        * Set the parameters of the request
+        
+        * @param $args Array
+        * @todo overload the args param
+        */
+       public function setData($args) {
+               $this->postData = $args;
+       }
+
        /**
         * Take care of setting up the proxy
         * (override in subclass)
-        * @return string
+        *
+        * @return String
         */
        public function proxySetup() {
                global $wgHTTPProxy;
 
-
                if ( $this->proxy ) {
                        return;
                }
@@ -216,6 +246,8 @@ class HttpRequest {
                        $this->proxy = 'http://localhost:80/';
                } elseif ( $wgHTTPProxy ) {
                        $this->proxy = $wgHTTPProxy ;
+               } elseif ( getenv( "http_proxy" ) ) {
+                       $this->proxy = getenv( "http_proxy" );
                }
        }
 
@@ -247,6 +279,11 @@ class HttpRequest {
        public function getHeaderList() {
                $list = array();
 
+               if( $this->cookieJar ) {
+                       $this->reqHeaders['Cookie'] =
+                               $this->cookieJar->serializeToHttpRequest($this->parsedUrl['path'],
+                                                                                                                $this->parsedUrl['host']);
+               }
                foreach($this->reqHeaders as $name => $value) {
                        $list[] = "$name: $value";
                }
@@ -255,16 +292,19 @@ class HttpRequest {
 
        /**
         * Set the callback
-        * @param $callback callback
+        *
+        * @param $callback Callback
         */
        public function setCallback( $callback ) {
                $this->callback = $callback;
        }
 
        /**
-        * A generic callback to read in the response from a remote server
+        * A generic callback to read the body of the response from a remote
+        * server.
+        *
         * @param $fh handle
-        * @param $content string
+        * @param $content String
         */
        public function read( $fh, $content ) {
                $this->content .= $content;
@@ -273,11 +313,14 @@ class HttpRequest {
 
        /**
         * Take care of whatever is necessary to perform the URI request.
+        *
         * @return Status
         */
        public function execute() {
                global $wgTitle;
 
+               $this->content = "";
+
                if( strtoupper($this->method) == "HEAD" ) {
                        $this->headersOnly = true;
                }
@@ -302,27 +345,418 @@ class HttpRequest {
                        $this->setUserAgent(Http::userAgent());
                }
        }
+
+       /**
+        * Parses the headers, including the HTTP status code and any
+        * Set-Cookie headers.  This function expectes the headers to be
+        * found in an array in the member variable headerList.
+        *
+        * @return nothing
+        */
+       protected function parseHeader() {
+               $lastname = "";
+               foreach( $this->headerList as $header ) {
+                       if( preg_match( "#^HTTP/([0-9.]+) (.*)#", $header, $match ) ) {
+                               $this->respVersion = $match[1];
+                               $this->respStatus = $match[2];
+                       } elseif( preg_match( "#^[ \t]#", $header ) ) {
+                               $last = count($this->respHeaders[$lastname]) - 1;
+                               $this->respHeaders[$lastname][$last] .= "\r\n$header";
+                       } elseif( preg_match( "#^([^:]*):[\t ]*(.*)#", $header, $match ) ) {
+                               $this->respHeaders[strtolower( $match[1] )][] = $match[2];
+                               $lastname = strtolower( $match[1] );
+                       }
+               }
+
+               $this->parseCookies();
+       }
+
+       /**
+        * Sets the member variable status to a fatal status if the HTTP
+        * status code was not 200.
+        *
+        * @return nothing
+        */
+       protected function setStatus() {
+               if( !$this->respHeaders ) {
+                       $this->parseHeader();
+               }
+
+               if((int)$this->respStatus !== 200) {
+                       list( $code, $message ) = explode(" ", $this->respStatus, 2);
+                       $this->status->fatal("http-bad-status", $code, $message );
+               }
+       }
+
+
+       /**
+        * Returns true if the last status code was a redirect.
+        *
+        * @return Boolean
+        */
+       public function isRedirect() {
+               if( !$this->respHeaders ) {
+                       $this->parseHeader();
+               }
+
+               $status = (int)$this->respStatus;
+               if ( $status >= 300 && $status <= 303 ) {
+                       return true;
+               }
+               return false;
+       }
+
+       /**
+        * Returns an associative array of response headers after the
+        * request has been executed.  Because some headers
+        * (e.g. Set-Cookie) can appear more than once the, each value of
+        * the associative array is an array of the values given.
+        *
+        * @return Array
+        */
+       public function getResponseHeaders() {
+               if( !$this->respHeaders ) {
+                       $this->parseHeader();
+               }
+               return $this->respHeaders;
+       }
+
+       /**
+        * Returns the value of the given response header.
+        *
+        * @param $header String
+        * @return String
+        */
+       public function getResponseHeader($header) {
+               if( !$this->respHeaders ) {
+                       $this->parseHeader();
+               }
+               if ( isset( $this->respHeaders[strtolower ( $header ) ] ) ) {
+                       $v = $this->respHeaders[strtolower ( $header ) ];
+                       return $v[count( $v ) - 1];
+               }
+               return null;
+       }
+
+       /**
+        * Tells the HttpRequest object to use this pre-loaded CookieJar.
+        *
+        * @param $jar CookieJar
+        */
+       public function setCookieJar( $jar ) {
+               $this->cookieJar = $jar;
+       }
+
+       /**
+        * Returns the cookie jar in use.
+        *
+        * @returns CookieJar
+        */
+       public function getCookieJar() {
+               if( !$this->respHeaders ) {
+                       $this->parseHeader();
+               }
+               return $this->cookieJar;
+       }
+
+       /**
+        * Sets a cookie.  Used before a request to set up any individual
+        * cookies.      Used internally after a request to parse the
+        * Set-Cookie headers.
+        * @see Cookie::set
+        */
+       public function setCookie( $name, $value = null, $attr = null) {
+               if( !$this->cookieJar ) {
+                       $this->cookieJar = new CookieJar;
+               }
+               $this->cookieJar->setCookie($name, $value, $attr);
+       }
+
+       /**
+        * Parse the cookies in the response headers and store them in the cookie jar.
+        */
+       protected function parseCookies() {
+               if( !$this->cookieJar ) {
+                       $this->cookieJar = new CookieJar;
+               }
+               if( isset( $this->respHeaders['set-cookie'] ) ) {
+                       $url = parse_url( $this->getFinalUrl() );
+                       foreach( $this->respHeaders['set-cookie'] as $cookie ) {
+                               $this->cookieJar->parseCookieResponseHeader( $cookie, $url['host'] );
+                       }
+               }
+       }
+
+       /**
+        * Returns the final URL after all redirections.
+        *
+        * @return String
+        */
+       public function getFinalUrl() {
+               $location = $this->getResponseHeader("Location");
+               if ( $location ) {
+                       return $location;
+               }
+
+               return $this->url;
+       }
+
+       /**
+        * Returns true if the backend can follow redirects. Overridden by the 
+        * child classes.
+        */
+       public function canFollowRedirects() {
+               return true;
+       }
 }
 
+
+class Cookie {
+       protected $name;
+       protected $value;
+       protected $expires;
+       protected $path;
+       protected $domain;
+       protected $isSessionKey = true;
+       // TO IMPLEMENT  protected $secure
+       // TO IMPLEMENT? protected $maxAge (add onto expires)
+       // TO IMPLEMENT? protected $version
+       // TO IMPLEMENT? protected $comment
+
+       function __construct( $name, $value, $attr ) {
+               $this->name = $name;
+               $this->set( $value, $attr );
+       }
+
+       /**
+        * Sets a cookie.  Used before a request to set up any individual
+        * cookies.      Used internally after a request to parse the
+        * Set-Cookie headers.
+        *
+        * @param $value String: the value of the cookie
+        * @param $attr Array: possible key/values:
+        *              expires  A date string
+        *              path     The path this cookie is used on
+        *              domain   Domain this cookie is used on
+        */
+       public function set( $value, $attr ) {
+               $this->value = $value;
+               if( isset( $attr['expires'] ) ) {
+                       $this->isSessionKey = false;
+                       $this->expires = strtotime( $attr['expires'] );
+               }
+               if( isset( $attr['path'] ) ) {
+                       $this->path = $attr['path'];
+               } else {
+                       $this->path = "/";
+               }
+               if( isset( $attr['domain'] ) ) {
+                       if( self::validateCookieDomain( $attr['domain'] ) ) {
+                               $this->domain = $attr['domain'];
+                       }
+               } else {
+                       throw new MWException("You must specify a domain.");
+               }
+       }
+
+       /**
+        * Return the true if the cookie is valid is valid.  Otherwise,
+        * false.  The uses a method similar to IE cookie security
+        * described here:
+        * http://kuza55.blogspot.com/2008/02/understanding-cookie-security.html
+        * A better method might be to use a blacklist like
+        * http://publicsuffix.org/
+        *
+        * @param $domain String: the domain to validate
+        * @param $originDomain String: (optional) the domain the cookie originates from
+        * @return Boolean
+        */
+       public static function validateCookieDomain( $domain, $originDomain = null) {
+               // Don't allow a trailing dot
+               if( substr( $domain, -1 ) == "." ) return false;
+
+               $dc = explode(".", $domain);
+
+               // Only allow full, valid IP addresses
+               if( preg_match( '/^[0-9.]+$/', $domain ) ) {
+                       if( count( $dc ) != 4 ) return false;
+
+                       if( ip2long( $domain ) === false ) return false;
+
+                       if( $originDomain == null || $originDomain == $domain ) return true;
+
+               }
+
+               // Don't allow cookies for "co.uk" or "gov.uk", etc, but allow "supermarket.uk"
+               if( strrpos( $domain, "." ) - strlen( $domain )  == -3 ) {
+                       if( (count($dc) == 2 && strlen( $dc[0] ) <= 2 )
+                               || (count($dc) == 3 && strlen( $dc[0] ) == "" && strlen( $dc[1] ) <= 2 ) ) {
+                               return false;
+                       }
+                       if( (count($dc) == 2 || (count($dc) == 3 && $dc[0] == "") )
+                               && preg_match( '/(com|net|org|gov|edu)\...$/', $domain) ) {
+                               return false;
+                       }
+               }
+
+               if( $originDomain != null ) {
+                       if( substr( $domain, 0, 1 ) != "." && $domain != $originDomain ) {
+                               return false;
+                       }
+                       if( substr( $domain, 0, 1 ) == "."
+                               && substr_compare( $originDomain, $domain, -strlen( $domain ),
+                                                                  strlen( $domain ), TRUE ) != 0 ) {
+                               return false;
+                       }
+               }
+
+               return true;
+       }
+
+       /**
+        * Serialize the cookie jar into a format useful for HTTP Request headers.
+        *
+        * @param $path String: the path that will be used. Required.
+        * @param $domain String: the domain that will be used. Required.
+        * @return String
+        */
+       public function serializeToHttpRequest( $path, $domain ) {
+               $ret = "";
+
+               if( $this->canServeDomain( $domain )
+                               && $this->canServePath( $path )
+                               && $this->isUnExpired() ) {
+                       $ret = $this->name ."=". $this->value;
+               }
+
+               return $ret;
+       }
+
+       protected function canServeDomain( $domain ) {
+               if( $domain == $this->domain
+                       || ( strlen( $domain) > strlen( $this->domain )
+                                && substr( $this->domain, 0, 1) == "."
+                                && substr_compare( $domain, $this->domain, -strlen( $this->domain ),
+                                                                       strlen( $this->domain ), TRUE ) == 0 ) ) {
+                       return true;
+               }
+               return false;
+       }
+
+       protected function canServePath( $path ) {
+               if( $this->path && substr_compare( $this->path, $path, 0, strlen( $this->path ) ) == 0 ) {
+                       return true;
+               }
+               return false;
+       }
+
+       protected function isUnExpired() {
+               if( $this->isSessionKey || $this->expires > time() ) {
+                       return true;
+               }
+               return false;
+       }
+
+}
+
+class CookieJar {
+       private $cookie = array();
+
+       /**
+        * Set a cookie in the cookie jar.      Make sure only one cookie per-name exists.
+        * @see Cookie::set()
+        */
+       public function setCookie ($name, $value, $attr) {
+               /* cookies: case insensitive, so this should work.
+                * We'll still send the cookies back in the same case we got them, though.
+                */
+               $index = strtoupper($name);
+               if( isset( $this->cookie[$index] ) ) {
+                       $this->cookie[$index]->set( $value, $attr );
+               } else {
+                       $this->cookie[$index] = new Cookie( $name, $value, $attr );
+               }
+       }
+
+       /**
+        * @see Cookie::serializeToHttpRequest
+        */
+       public function serializeToHttpRequest( $path, $domain ) {
+               $cookies = array();
+
+               foreach( $this->cookie as $c ) {
+                       $serialized = $c->serializeToHttpRequest( $path, $domain );
+                       if ( $serialized ) $cookies[] = $serialized;
+               }
+
+               return implode("; ", $cookies);
+       }
+
+       /**
+        * Parse the content of an Set-Cookie HTTP Response header.
+        *
+        * @param $cookie String
+        * @param $domain String: cookie's domain
+        */
+       public function parseCookieResponseHeader ( $cookie, $domain ) {
+               $len = strlen( "Set-Cookie:" );
+               if ( substr_compare( "Set-Cookie:", $cookie, 0, $len, TRUE ) === 0 ) {
+                       $cookie = substr( $cookie, $len );
+               }
+
+               $bit = array_map( 'trim', explode( ";", $cookie ) );
+               if ( count($bit) >= 1 ) {
+                       list($name, $value) = explode( "=", array_shift( $bit ), 2 );
+                       $attr = array();
+                       foreach( $bit as $piece ) {
+                               $parts = explode( "=", $piece );
+                               if( count( $parts ) > 1 ) {
+                                       $attr[strtolower( $parts[0] )] = $parts[1];
+                               } else {
+                                       $attr[strtolower( $parts[0] )] = true;
+                               }
+                       }
+
+                       if( !isset( $attr['domain'] ) ) {
+                               $attr['domain'] = $domain;
+                       } elseif ( !Cookie::validateCookieDomain( $attr['domain'], $domain ) ) {
+                               return null;
+                       }
+                       $this->setCookie( $name, $value, $attr );
+               }
+       }
+}
+
+
 /**
  * HttpRequest implemented using internal curl compiled into PHP
  */
 class CurlHttpRequest extends HttpRequest {
+       static $curlMessageMap = array(
+               6 => 'http-host-unreachable',
+               28 => 'http-timed-out'
+       );
+
        protected $curlOptions = array();
+       protected $headerText = "";
+
+       protected function readHeader( $fh, $content ) {
+               $this->headerText .= $content;
+               return strlen( $content );
+       }
 
        public function execute() {
                parent::execute();
                if ( !$this->status->isOK() ) {
                        return $this->status;
                }
-
-               // A lot of the action up front should probably be in
-               // set* methods, but we'll leave that for another time.
-
                $this->curlOptions[CURLOPT_PROXY] = $this->proxy;
                $this->curlOptions[CURLOPT_TIMEOUT] = $this->timeout;
                $this->curlOptions[CURLOPT_HTTP_VERSION] = CURL_HTTP_VERSION_1_0;
                $this->curlOptions[CURLOPT_WRITEFUNCTION] = $this->callback;
+               $this->curlOptions[CURLOPT_HEADERFUNCTION] = array($this, "readHeader");
+               $this->curlOptions[CURLOPT_MAXREDIRS] = $this->maxRedirects;
+               $this->curlOptions[CURLOPT_ENCODING] = ""; # Enable compression
 
                /* not sure these two are actually necessary */
                if(isset($this->reqHeaders['Referer'])) {
@@ -330,9 +764,13 @@ class CurlHttpRequest extends HttpRequest {
                }
                $this->curlOptions[CURLOPT_USERAGENT] = $this->reqHeaders['User-Agent'];
 
-               if ( $this->sslVerifyHost ) {
+               if ( isset( $this->sslVerifyHost ) ) {
                        $this->curlOptions[CURLOPT_SSL_VERIFYHOST] = $this->sslVerifyHost;
                }
+               
+               if ( isset( $this->sslVerifyCert ) ) {
+                       $this->curlOptions[CURLOPT_SSL_VERIFYPEER] = $this->sslVerifyCert;
+               }
 
                if ( $this->caInfo ) {
                        $this->curlOptions[CURLOPT_CAINFO] = $this->caInfo;
@@ -355,22 +793,51 @@ class CurlHttpRequest extends HttpRequest {
                $this->curlOptions[CURLOPT_HTTPHEADER] = $this->getHeaderList();
 
                $curlHandle = curl_init( $this->url );
-               curl_setopt_array( $curlHandle, $this->curlOptions );
+               if ( !curl_setopt_array( $curlHandle, $this->curlOptions ) ) {
+                       throw new MWException("Error setting curl options.");
+               }
+               if ( $this->followRedirects && $this->canFollowRedirects() ) {
+                       if ( ! @curl_setopt( $curlHandle, CURLOPT_FOLLOWLOCATION, true ) ) {
+                               wfDebug( __METHOD__.": Couldn't set CURLOPT_FOLLOWLOCATION. " .
+                                       "Probably safe_mode or open_basedir is set.\n");
+                               // Continue the processing. If it were in curl_setopt_array, 
+                               // processing would have halted on its entry
+                       }
+               }
 
                if ( false === curl_exec( $curlHandle ) ) {
-                       // re-using already translated error messages
-                       $this->status->fatal( 'upload-curl-error'.curl_errno( $curlHandle ).'-text' );
+                       $code = curl_error( $curlHandle );
+
+                       if ( isset( self::$curlMessageMap[$code] ) ) {
+                               $this->status->fatal( self::$curlMessageMap[$code] );
+                       } else {
+                               $this->status->fatal( 'http-curl-error', curl_error( $curlHandle ) );
+                       }
+               } else {
+                       $this->headerList = explode("\r\n", $this->headerText);
                }
 
                curl_close( $curlHandle );
 
+               $this->parseHeader();
+               $this->setStatus();
                return $this->status;
        }
+
+       public function canFollowRedirects() {
+               if ( strval( ini_get( 'open_basedir' ) ) !== '' || wfIniGetBool( 'safe_mode' ) ) {
+                       wfDebug( "Cannot follow redirects in safe mode\n" );
+                       return false;
+               }
+               if ( !defined( 'CURLOPT_REDIR_PROTOCOLS' ) ) {
+                       wfDebug( "Cannot follow redirects with libcurl < 7.19.4 due to CVE-2009-0037\n" );
+                       return false;
+               }
+               return true;
+       }
 }
 
 class PhpHttpRequest extends HttpRequest {
-       private $fh;
-
        protected function urlToTcp( $url ) {
                $parsedUrl = parse_url( $url );
 
@@ -378,17 +845,15 @@ class PhpHttpRequest extends HttpRequest {
        }
 
        public function execute() {
-               if ( $this->parsedUrl['scheme'] != 'http' ) {
-                       $this->status->fatal( 'http-invalid-scheme', $this->parsedURL['scheme'] );
-           }
-
                parent::execute();
-               if ( !$this->status->isOK() ) {
-                       return $this->status;
-               }
 
-               // A lot of the action up front should probably be in
-               // set* methods, but we'll leave that for another time.
+               // At least on Centos 4.8 with PHP 5.1.6, using max_redirects to follow redirects
+               // causes a segfault
+               $manuallyRedirect = version_compare( phpversion(), '5.1.7', '<' );
+
+               if ( $this->parsedUrl['scheme'] != 'http' ) {
+                       $this->status->fatal( 'http-invalid-scheme', $this->parsedUrl['scheme'] );
+               }
 
                $this->reqHeaders['Accept'] = "*/*";
                if ( $this->method == 'POST' ) {
@@ -403,46 +868,94 @@ class PhpHttpRequest extends HttpRequest {
                        $options['request_fulluri'] = true;
                }
 
+               if ( !$this->followRedirects || $manuallyRedirect ) {
+                       $options['max_redirects'] = 0;
+               } else {
+                       $options['max_redirects'] = $this->maxRedirects;
+               }
+
                $options['method'] = $this->method;
-               $options['timeout'] = $this->timeout;
                $options['header'] = implode("\r\n", $this->getHeaderList());
-               // FOR NOW: Force everyone to HTTP 1.0
-               /* if ( version_compare( "5.3.0", phpversion(), ">" ) ) { */
-                       $options['protocol_version'] = "1.0";
-               /* } else { */
-               /*      $options['protocol_version'] = "1.1"; */
-               /* } */
+               // Note that at some future point we may want to support
+               // HTTP/1.1, but we'd have to write support for chunking
+               // in version of PHP < 5.3.1
+               $options['protocol_version'] = "1.0";
+
+               // This is how we tell PHP we want to deal with 404s (for example) ourselves.
+               // Only works on 5.2.10+
+               $options['ignore_errors'] = true;
 
                if ( $this->postData ) {
                        $options['content'] = $this->postData;
                }
 
+               $oldTimeout = false;
+               if ( version_compare( '5.2.1', phpversion(), '>' ) ) {
+                       $oldTimeout = ini_set('default_socket_timeout', $this->timeout);
+               } else {
+                       $options['timeout'] = $this->timeout;
+               }
+
                $context = stream_context_create( array( 'http' => $options ) );
-               try {
-                       $this->fh = fopen( $this->url, "r", false, $context );
-               } catch ( Exception $e ) {
-                       $this->status->fatal( $e->getMessage() ); /* need some l10n help */
+
+               $this->headerList = array();
+               $reqCount = 0;
+               $url = $this->url;
+               do {
+                       $reqCount++;
+                       wfSuppressWarnings();
+                       $fh = fopen( $url, "r", false, $context );
+                       wfRestoreWarnings();
+                       if ( !$fh ) {
+                               break;
+                       }
+                       $result = stream_get_meta_data( $fh );
+                       $this->headerList = $result['wrapper_data'];
+                       $this->parseHeader();
+                       if ( !$manuallyRedirect || !$this->followRedirects ) {
+                               break;
+                       }
+
+                       # Handle manual redirection
+                       if ( !$this->isRedirect() || $reqCount > $this->maxRedirects ) {
+                               break;
+                       }
+                       # Check security of URL
+                       $url = $this->getResponseHeader("Location");
+                       if ( substr( $url, 0, 7 ) !== 'http://' ) {
+                               wfDebug( __METHOD__.": insecure redirection\n" );
+                               break;
+                       }
+               } while ( true );
+
+               if ( $oldTimeout !== false ) {
+                       ini_set('default_socket_timeout', $oldTimeout);
+               }
+               $this->setStatus();
+
+               if ( $fh === false ) {
+                       $this->status->fatal( 'http-request-error' );
                        return $this->status;
                }
 
-               $result = stream_get_meta_data( $this->fh );
                if ( $result['timed_out'] ) {
                        $this->status->fatal( 'http-timed-out', $this->url );
                        return $this->status;
                }
 
-               $this->headers = $result['wrapper_data'];
-
-               $end = false;
-               while ( !$end ) {
-                       $contents = fread( $this->fh, 8192 );
-                       $size = 0;
-                       if ( $contents ) {
-                               $size = call_user_func_array( $this->callback, array( $this->fh, $contents ) );
+               if($this->status->isOK()) {
+                       while ( !feof( $fh ) ) {
+                               $buf = fread( $fh, 8192 );
+                               if ( $buf === false ) {
+                                       $this->status->fatal( 'http-read-error' );
+                                       break;
+                               }
+                               if ( strlen( $buf ) ) {
+                                       call_user_func( $this->callback, $fh, $buf );
+                               }
                        }
-                       $end = ( $size == 0 )  || feof( $this->fh );
                }
-               fclose( $this->fh );
+               fclose( $fh );
 
                return $this->status;
        }