User::isSafeToLoad() should return false if MW_NO_SESSION

[mediawiki.git] / includes / HttpFunctions.php

<?php
/**
 * Various HTTP related functions.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program; if not, write to the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 * http://www.gnu.org/copyleft/gpl.html
 *
 * @file
 * @ingroup HTTP
 */

/**
 * @defgroup HTTP HTTP
 */

use MediaWiki\Logger\LoggerFactory;

/**
 * Various HTTP related functions
 * @ingroup HTTP
 */
class Http {
        static public $httpEngine = false;

        /**
         * Perform an HTTP request
         *
         * @param string $method HTTP method. Usually GET/POST
         * @param string $url Full URL to act on. If protocol-relative, will be expanded to an http:// URL
         * @param array $options Options to pass to MWHttpRequest object.
         *      Possible keys for the array:
         *    - timeout             Timeout length in seconds
         *    - connectTimeout      Timeout for connection, in seconds (curl only)
         *    - postData            An array of key-value pairs or a url-encoded form data
         *    - proxy               The proxy to use.
         *                          Otherwise it will use $wgHTTPProxy (if set)
         *                          Otherwise it will use the environment variable "http_proxy" (if set)
         *    - noProxy             Don't use any proxy at all. Takes precedence over proxy value(s).
         *    - sslVerifyHost       Verify hostname against certificate
         *    - sslVerifyCert       Verify SSL certificate
         *    - caInfo              Provide CA information
         *    - maxRedirects        Maximum number of redirects to follow (defaults to 5)
         *    - followRedirects     Whether to follow redirects (defaults to false).
         *                                  Note: this should only be used when the target URL is trusted,
         *                                  to avoid attacks on intranet services accessible by HTTP.
         *    - userAgent           A user agent, if you want to override the default
         *                          MediaWiki/$wgVersion
         * @param string $caller The method making this request, for profiling
         * @return string|bool (bool)false on failure or a string on success
         */
        public static function request( $method, $url, $options = [], $caller = __METHOD__ ) {
                wfDebug( "HTTP: $method: $url\n" );

                $options['method'] = strtoupper( $method );

                if ( !isset( $options['timeout'] ) ) {
                        $options['timeout'] = 'default';
                }
                if ( !isset( $options['connectTimeout'] ) ) {
                        $options['connectTimeout'] = 'default';
                }

                $req = MWHttpRequest::factory( $url, $options, $caller );
                $status = $req->execute();

                if ( $status->isOK() ) {
                        return $req->getContent();
                } else {
                        $errors = $status->getErrorsByType( 'error' );
                        $logger = LoggerFactory::getInstance( 'http' );
                        $logger->warning( $status->getWikiText(),
                                [ 'error' => $errors, 'caller' => $caller, 'content' => $req->getContent() ] );
                        return false;
                }
        }

        /**
         * Simple wrapper for Http::request( 'GET' )
         * @see Http::request()
         * @since 1.25 Second parameter $timeout removed. Second parameter
         * is now $options which can be given a 'timeout'
         *
         * @param string $url
         * @param array $options
         * @param string $caller The method making this request, for profiling
         * @return string|bool false on error
         */
        public static function get( $url, $options = [], $caller = __METHOD__ ) {
                $args = func_get_args();
                if ( isset( $args[1] ) && ( is_string( $args[1] ) || is_numeric( $args[1] ) ) ) {
                        // Second was used to be the timeout
                        // And third parameter used to be $options
                        wfWarn( "Second parameter should not be a timeout.", 2 );
                        $options = isset( $args[2] ) && is_array( $args[2] ) ?
                                $args[2] : [];
                        $options['timeout'] = $args[1];
                        $caller = __METHOD__;
                }
                return Http::request( 'GET', $url, $options, $caller );
        }

        /**
         * Simple wrapper for Http::request( 'POST' )
         * @see Http::request()
         *
         * @param string $url
         * @param array $options
         * @param string $caller The method making this request, for profiling
         * @return string|bool false on error
         */
        public static function post( $url, $options = [], $caller = __METHOD__ ) {
                return Http::request( 'POST', $url, $options, $caller );
        }

        /**
         * Check if the URL can be served by localhost
         *
         * @param string $url Full url to check
         * @return bool
         */
        public static function isLocalURL( $url ) {
                global $wgCommandLineMode, $wgLocalVirtualHosts;

                if ( $wgCommandLineMode ) {
                        return false;
                }

                // Extract host part
                $matches = [];
                if ( preg_match( '!^http://([\w.-]+)[/:].*$!', $url, $matches ) ) {
                        $host = $matches[1];
                        // Split up dotwise
                        $domainParts = explode( '.', $host );
                        // Check if this domain or any superdomain is listed as a local virtual host
                        $domainParts = array_reverse( $domainParts );

                        $domain = '';
                        $countParts = count( $domainParts );
                        for ( $i = 0; $i < $countParts; $i++ ) {
                                $domainPart = $domainParts[$i];
                                if ( $i == 0 ) {
                                        $domain = $domainPart;
                                } else {
                                        $domain = $domainPart . '.' . $domain;
                                }

                                if ( in_array( $domain, $wgLocalVirtualHosts ) ) {
                                        return true;
                                }
                        }
                }

                return false;
        }

        /**
         * A standard user-agent we can use for external requests.
         * @return string
         */
        public static function userAgent() {
                global $wgVersion;
                return "MediaWiki/$wgVersion";
        }

        /**
         * Checks that the given URI is a valid one. Hardcoding the
         * protocols, because we only want protocols that both cURL
         * and php support.
         *
         * file:// should not be allowed here for security purpose (r67684)
         *
         * @todo FIXME this is wildly inaccurate and fails to actually check most stuff
         *
         * @param string $uri URI to check for validity
         * @return bool
         */
        public static function isValidURI( $uri ) {
                return preg_match(
                        '/^https?:\/\/[^\/\s]\S*$/D',
                        $uri
                );
        }
}

/**
 * This wrapper class will call out to curl (if available) or fallback
 * to regular PHP if necessary for handling internal HTTP requests.
 *
 * Renamed from HttpRequest to MWHttpRequest to avoid conflict with
 * PHP's HTTP extension.
 */
class MWHttpRequest {
        const SUPPORTS_FILE_POSTS = false;

        protected $content;
        protected $timeout = 'default';
        protected $headersOnly = null;
        protected $postData = null;
        protected $proxy = null;
        protected $noProxy = false;
        protected $sslVerifyHost = true;
        protected $sslVerifyCert = true;
        protected $caInfo = null;
        protected $method = "GET";
        protected $reqHeaders = [];
        protected $url;
        protected $parsedUrl;
        protected $callback;
        protected $maxRedirects = 5;
        protected $followRedirects = false;

        /**
         * @var CookieJar
         */
        protected $cookieJar;

        protected $headerList = [];
        protected $respVersion = "0.9";
        protected $respStatus = "200 Ok";
        protected $respHeaders = [];

        public $status;

        /**
         * @var Profiler
         */
        protected $profiler;

        /**
         * @var string
         */
        protected $profileName;

        /**
         * @param string $url Url to use. If protocol-relative, will be expanded to an http:// URL
         * @param array $options (optional) extra params to pass (see Http::request())
         * @param string $caller The method making this request, for profiling
         * @param Profiler $profiler An instance of the profiler for profiling, or null
         */
        protected function __construct(
                $url, $options = [], $caller = __METHOD__, $profiler = null
        ) {
                global $wgHTTPTimeout, $wgHTTPConnectTimeout;

                $this->url = wfExpandUrl( $url, PROTO_HTTP );
                $this->parsedUrl = wfParseUrl( $this->url );

                if ( !$this->parsedUrl || !Http::isValidURI( $this->url ) ) {
                        $this->status = Status::newFatal( 'http-invalid-url', $url );
                } else {
                        $this->status = Status::newGood( 100 ); // continue
                }

                if ( isset( $options['timeout'] ) && $options['timeout'] != 'default' ) {
                        $this->timeout = $options['timeout'];
                } else {
                        $this->timeout = $wgHTTPTimeout;
                }
                if ( isset( $options['connectTimeout'] ) && $options['connectTimeout'] != 'default' ) {
                        $this->connectTimeout = $options['connectTimeout'];
                } else {
                        $this->connectTimeout = $wgHTTPConnectTimeout;
                }
                if ( isset( $options['userAgent'] ) ) {
                        $this->setUserAgent( $options['userAgent'] );
                }

                $members = [ "postData", "proxy", "noProxy", "sslVerifyHost", "caInfo",
                                "method", "followRedirects", "maxRedirects", "sslVerifyCert", "callback" ];

                foreach ( $members as $o ) {
                        if ( isset( $options[$o] ) ) {
                                // ensure that MWHttpRequest::method is always
                                // uppercased. Bug 36137
                                if ( $o == 'method' ) {
                                        $options[$o] = strtoupper( $options[$o] );
                                }
                                $this->$o = $options[$o];
                        }
                }

                if ( $this->noProxy ) {
                        $this->proxy = ''; // noProxy takes precedence
                }

                // Profile based on what's calling us
                $this->profiler = $profiler;
                $this->profileName = $caller;
        }

        /**
         * Simple function to test if we can make any sort of requests at all, using
         * cURL or fopen()
         * @return bool
         */
        public static function canMakeRequests() {
                return function_exists( 'curl_init' ) || wfIniGetBool( 'allow_url_fopen' );
        }

        /**
         * Generate a new request object
         * @param string $url Url to use
         * @param array $options (optional) extra params to pass (see Http::request())
         * @param string $caller The method making this request, for profiling
         * @throws MWException
         * @return CurlHttpRequest|PhpHttpRequest
         * @see MWHttpRequest::__construct
         */
        public static function factory( $url, $options = null, $caller = __METHOD__ ) {
                if ( !Http::$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 ( Http::$httpEngine ) {
                        case 'curl':
                                return new CurlHttpRequest( $url, $options, $caller, Profiler::instance() );
                        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.'
                                        );
                                }
                                return new PhpHttpRequest( $url, $options, $caller, Profiler::instance() );
                        default:
                                throw new MWException( __METHOD__ . ': The setting of Http::$httpEngine is not valid.' );
                }
        }

        /**
         * Get the body, or content, of the response to the request
         *
         * @return string
         */
        public function getContent() {
                return $this->content;
        }

        /**
         * Set the parameters of the request
         *
         * @param array $args
         * @todo overload the args param
         */
        public function setData( $args ) {
                $this->postData = $args;
        }

        /**
         * Take care of setting up the proxy (do nothing if "noProxy" is set)
         *
         * @return void
         */
        public function proxySetup() {
                global $wgHTTPProxy;

                // If there is an explicit proxy set and proxies are not disabled, then use it
                if ( $this->proxy && !$this->noProxy ) {
                        return;
                }

                // Otherwise, fallback to $wgHTTPProxy/http_proxy (when set) if this is not a machine
                // local URL and proxies are not disabled
                if ( Http::isLocalURL( $this->url ) || $this->noProxy ) {
                        $this->proxy = '';
                } elseif ( $wgHTTPProxy ) {
                        $this->proxy = $wgHTTPProxy;
                } elseif ( getenv( "http_proxy" ) ) {
                        $this->proxy = getenv( "http_proxy" );
                }
        }

        /**
         * Set the user agent
         * @param string $UA
         */
        public function setUserAgent( $UA ) {
                $this->setHeader( 'User-Agent', $UA );
        }

        /**
         * Set an arbitrary header
         * @param string $name
         * @param string $value
         */
        public function setHeader( $name, $value ) {
                // I feel like I should normalize the case here...
                $this->reqHeaders[$name] = $value;
        }

        /**
         * Get an array of the headers
         * @return array
         */
        public function getHeaderList() {
                $list = [];

                if ( $this->cookieJar ) {
                        $this->reqHeaders['Cookie'] =
                                $this->cookieJar->serializeToHttpRequest(
                                        $this->parsedUrl['path'],
                                        $this->parsedUrl['host']
                                );
                }

                foreach ( $this->reqHeaders as $name => $value ) {
                        $list[] = "$name: $value";
                }

                return $list;
        }

        /**
         * Set a read callback to accept data read from the HTTP request.
         * By default, data is appended to an internal buffer which can be
         * retrieved through $req->getContent().
         *
         * To handle data as it comes in -- especially for large files that
         * would not fit in memory -- you can instead set your own callback,
         * in the form function($resource, $buffer) where the first parameter
         * is the low-level resource being read (implementation specific),
         * and the second parameter is the data buffer.
         *
         * You MUST return the number of bytes handled in the buffer; if fewer
         * bytes are reported handled than were passed to you, the HTTP fetch
         * will be aborted.
         *
         * @param callable $callback
         * @throws MWException
         */
        public function setCallback( $callback ) {
                if ( !is_callable( $callback ) ) {
                        throw new MWException( 'Invalid MwHttpRequest callback' );
                }
                $this->callback = $callback;
        }

        /**
         * A generic callback to read the body of the response from a remote
         * server.
         *
         * @param resource $fh
         * @param string $content
         * @return int
         */
        public function read( $fh, $content ) {
                $this->content .= $content;
                return strlen( $content );
        }

        /**
         * Take care of whatever is necessary to perform the URI request.
         *
         * @return Status
         */
        public function execute() {

                $this->content = "";

                if ( strtoupper( $this->method ) == "HEAD" ) {
                        $this->headersOnly = true;
                }

                $this->proxySetup(); // set up any proxy as needed

                if ( !$this->callback ) {
                        $this->setCallback( [ $this, 'read' ] );
                }

                if ( !isset( $this->reqHeaders['User-Agent'] ) ) {
                        $this->setUserAgent( Http::userAgent() );
                }

        }

        /**
         * Parses the headers, including the HTTP status code and any
         * Set-Cookie headers.  This function expects the headers to be
         * found in an array in the member variable headerList.
         */
        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 HTTPRequest status member to a fatal value with the error
         * message if the returned integer value of the status code was
         * not successful (< 300) or a redirect (>=300 and < 400).  (see
         * RFC2616, section 10,
         * http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html for a
         * list of status codes.)
         */
        protected function setStatus() {
                if ( !$this->respHeaders ) {
                        $this->parseHeader();
                }

                if ( (int)$this->respStatus > 399 ) {
                        list( $code, $message ) = explode( " ", $this->respStatus, 2 );
                        $this->status->fatal( "http-bad-status", $code, $message );
                }
        }

        /**
         * Get the integer value of the HTTP status code (e.g. 200 for "200 Ok")
         * (see RFC2616, section 10, http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html
         * for a list of status codes.)
         *
         * @return int
         */
        public function getStatus() {
                if ( !$this->respHeaders ) {
                        $this->parseHeader();
                }

                return (int)$this->respStatus;
        }

        /**
         * Returns true if the last status code was a redirect.
         *
         * @return bool
         */
        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 string $header
         * @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 MWHttpRequest object to use this pre-loaded CookieJar.
         *
         * @param CookieJar $jar
         */
        public function setCookieJar( $jar ) {
                $this->cookieJar = $jar;
        }

        /**
         * Returns the cookie jar in use.
         *
         * @return 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
         * @param string $name
         * @param mixed $value
         * @param array $attr
         */
        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.
         *
         * Relative values of the "Location" header are incorrect as
         * stated in RFC, however they do happen and modern browsers
         * support them.  This function loops backwards through all
         * locations in order to build the proper absolute URI - Marooned
         * at wikia-inc.com
         *
         * Note that the multiple Location: headers are an artifact of
         * CURL -- they shouldn't actually get returned this way. Rewrite
         * this when bug 29232 is taken care of (high-level redirect
         * handling rewrite).
         *
         * @return string
         */
        public function getFinalUrl() {
                $headers = $this->getResponseHeaders();

                // return full url (fix for incorrect but handled relative location)
                if ( isset( $headers['location'] ) ) {
                        $locations = $headers['location'];
                        $domain = '';
                        $foundRelativeURI = false;
                        $countLocations = count( $locations );

                        for ( $i = $countLocations - 1; $i >= 0; $i-- ) {
                                $url = parse_url( $locations[$i] );

                                if ( isset( $url['host'] ) ) {
                                        $domain = $url['scheme'] . '://' . $url['host'];
                                        break; // found correct URI (with host)
                                } else {
                                        $foundRelativeURI = true;
                                }
                        }

                        if ( $foundRelativeURI ) {
                                if ( $domain ) {
                                        return $domain . $locations[$countLocations - 1];
                                } else {
                                        $url = parse_url( $this->url );
                                        if ( isset( $url['host'] ) ) {
                                                return $url['scheme'] . '://' . $url['host'] .
                                                        $locations[$countLocations - 1];
                                        }
                                }
                        } else {
                                return $locations[$countLocations - 1];
                        }
                }

                return $this->url;
        }

        /**
         * Returns true if the backend can follow redirects. Overridden by the
         * child classes.
         * @return bool
         */
        public function canFollowRedirects() {
                return true;
        }
}

/**
 * MWHttpRequest implemented using internal curl compiled into PHP
 */
class CurlHttpRequest extends MWHttpRequest {
        const SUPPORTS_FILE_POSTS = true;

        protected $curlOptions = [];
        protected $headerText = "";

        /**
         * @param resource $fh
         * @param string $content
         * @return int
         */
        protected function readHeader( $fh, $content ) {
                $this->headerText .= $content;
                return strlen( $content );
        }

        public function execute() {

                parent::execute();

                if ( !$this->status->isOK() ) {
                        return $this->status;
                }

                $this->curlOptions[CURLOPT_PROXY] = $this->proxy;
                $this->curlOptions[CURLOPT_TIMEOUT] = $this->timeout;

                // Only supported in curl >= 7.16.2
                if ( defined( 'CURLOPT_CONNECTTIMEOUT_MS' ) ) {
                        $this->curlOptions[CURLOPT_CONNECTTIMEOUT_MS] = $this->connectTimeout * 1000;
                }

                $this->curlOptions[CURLOPT_HTTP_VERSION] = CURL_HTTP_VERSION_1_0;
                $this->curlOptions[CURLOPT_WRITEFUNCTION] = $this->callback;
                $this->curlOptions[CURLOPT_HEADERFUNCTION] = [ $this, "readHeader" ];
                $this->curlOptions[CURLOPT_MAXREDIRS] = $this->maxRedirects;
                $this->curlOptions[CURLOPT_ENCODING] = ""; # Enable compression

                $this->curlOptions[CURLOPT_USERAGENT] = $this->reqHeaders['User-Agent'];

                $this->curlOptions[CURLOPT_SSL_VERIFYHOST] = $this->sslVerifyHost ? 2 : 0;
                $this->curlOptions[CURLOPT_SSL_VERIFYPEER] = $this->sslVerifyCert;

                if ( $this->caInfo ) {
                        $this->curlOptions[CURLOPT_CAINFO] = $this->caInfo;
                }

                if ( $this->headersOnly ) {
                        $this->curlOptions[CURLOPT_NOBODY] = true;
                        $this->curlOptions[CURLOPT_HEADER] = true;
                } elseif ( $this->method == 'POST' ) {
                        $this->curlOptions[CURLOPT_POST] = true;
                        $postData = $this->postData;
                        // Don't interpret POST parameters starting with '@' as file uploads, because this
                        // makes it impossible to POST plain values starting with '@' (and causes security
                        // issues potentially exposing the contents of local files).
                        // The PHP manual says this option was introduced in PHP 5.5 defaults to true in PHP 5.6,
                        // but we support lower versions, and the option doesn't exist in HHVM 5.6.99.
                        if ( defined( 'CURLOPT_SAFE_UPLOAD' ) ) {
                                $this->curlOptions[CURLOPT_SAFE_UPLOAD] = true;
                        } elseif ( is_array( $postData ) ) {
                                // In PHP 5.2 and later, '@' is interpreted as a file upload if POSTFIELDS
                                // is an array, but not if it's a string. So convert $req['body'] to a string
                                // for safety.
                                $postData = wfArrayToCgi( $postData );
                        }
                        $this->curlOptions[CURLOPT_POSTFIELDS] = $postData;

                        // Suppress 'Expect: 100-continue' header, as some servers
                        // will reject it with a 417 and Curl won't auto retry
                        // with HTTP 1.0 fallback
                        $this->reqHeaders['Expect'] = '';
                } else {
                        $this->curlOptions[CURLOPT_CUSTOMREQUEST] = $this->method;
                }

                $this->curlOptions[CURLOPT_HTTPHEADER] = $this->getHeaderList();

                $curlHandle = curl_init( $this->url );

                if ( !curl_setopt_array( $curlHandle, $this->curlOptions ) ) {
                        throw new MWException( "Error setting curl options." );
                }

                if ( $this->followRedirects && $this->canFollowRedirects() ) {
                        MediaWiki\suppressWarnings();
                        if ( !curl_setopt( $curlHandle, CURLOPT_FOLLOWLOCATION, true ) ) {
                                wfDebug( __METHOD__ . ": Couldn't set CURLOPT_FOLLOWLOCATION. " .
                                        "Probably open_basedir is set.\n" );
                                // Continue the processing. If it were in curl_setopt_array,
                                // processing would have halted on its entry
                        }
                        MediaWiki\restoreWarnings();
                }

                if ( $this->profiler ) {
                        $profileSection = $this->profiler->scopedProfileIn(
                                __METHOD__ . '-' . $this->profileName
                        );
                }

                $curlRes = curl_exec( $curlHandle );
                if ( curl_errno( $curlHandle ) == CURLE_OPERATION_TIMEOUTED ) {
                        $this->status->fatal( 'http-timed-out', $this->url );
                } elseif ( $curlRes === false ) {
                        $this->status->fatal( 'http-curl-error', curl_error( $curlHandle ) );
                } else {
                        $this->headerList = explode( "\r\n", $this->headerText );
                }

                curl_close( $curlHandle );

                if ( $this->profiler ) {
                        $this->profiler->scopedProfileOut( $profileSection );
                }

                $this->parseHeader();
                $this->setStatus();

                return $this->status;
        }

        /**
         * @return bool
         */
        public function canFollowRedirects() {
                $curlVersionInfo = curl_version();
                if ( $curlVersionInfo['version_number'] < 0x071304 ) {
                        wfDebug( "Cannot follow redirects with libcurl < 7.19.4 due to CVE-2009-0037\n" );
                        return false;
                }

                if ( version_compare( PHP_VERSION, '5.6.0', '<' ) ) {
                        if ( strval( ini_get( 'open_basedir' ) ) !== '' ) {
                                wfDebug( "Cannot follow redirects when open_basedir is set\n" );
                                return false;
                        }
                }

                return true;
        }
}

class PhpHttpRequest extends MWHttpRequest {

        private $fopenErrors = [];

        /**
         * @param string $url
         * @return string
         */
        protected function urlToTcp( $url ) {
                $parsedUrl = parse_url( $url );

                return 'tcp://' . $parsedUrl['host'] . ':' . $parsedUrl['port'];
        }

        /**
         * Returns an array with a 'capath' or 'cafile' key
         * that is suitable to be merged into the 'ssl' sub-array of
         * a stream context options array.
         * Uses the 'caInfo' option of the class if it is provided, otherwise uses the system
         * default CA bundle if PHP supports that, or searches a few standard locations.
         * @return array
         * @throws DomainException
         */
        protected function getCertOptions() {
                $certOptions = [];
                $certLocations = [];
                if ( $this->caInfo ) {
                        $certLocations = [ 'manual' => $this->caInfo ];
                } elseif ( version_compare( PHP_VERSION, '5.6.0', '<' ) ) {
                        // @codingStandardsIgnoreStart Generic.Files.LineLength
                        // Default locations, based on
                        // https://www.happyassassin.net/2015/01/12/a-note-about-ssltls-trusted-certificate-stores-and-platforms/
                        // PHP 5.5 and older doesn't have any defaults, so we try to guess ourselves.
                        // PHP 5.6+ gets the CA location from OpenSSL as long as it is not set manually,
                        // so we should leave capath/cafile empty there.
                        // @codingStandardsIgnoreEnd
                        $certLocations = array_filter( [
                                getenv( 'SSL_CERT_DIR' ),
                                getenv( 'SSL_CERT_PATH' ),
                                '/etc/pki/tls/certs/ca-bundle.crt', # Fedora et al
                                '/etc/ssl/certs',  # Debian et al
                                '/etc/pki/tls/certs/ca-bundle.trust.crt',
                                '/etc/pki/ca-trust/extracted/pem/tls-ca-bundle.pem',
                                '/System/Library/OpenSSL', # OSX
                        ] );
                }

                foreach ( $certLocations as $key => $cert ) {
                        if ( is_dir( $cert ) ) {
                                $certOptions['capath'] = $cert;
                                break;
                        } elseif ( is_file( $cert ) ) {
                                $certOptions['cafile'] = $cert;
                                break;
                        } elseif ( $key === 'manual' ) {
                                // fail more loudly if a cert path was manually configured and it is not valid
                                throw new DomainException( "Invalid CA info passed: $cert" );
                        }
                }

                return $certOptions;
        }

        /**
         * Custom error handler for dealing with fopen() errors.
         * fopen() tends to fire multiple errors in succession, and the last one
         * is completely useless (something like "fopen: failed to open stream")
         * so normal methods of handling errors programmatically
         * like get_last_error() don't work.
         */
        public function errorHandler( $errno, $errstr ) {
                $n = count( $this->fopenErrors ) + 1;
                $this->fopenErrors += [ "errno$n" => $errno, "errstr$n" => $errstr ];
        }

        public function execute() {

                parent::execute();

                if ( is_array( $this->postData ) ) {
                        $this->postData = wfArrayToCgi( $this->postData );
                }

                if ( $this->parsedUrl['scheme'] != 'http'
                        && $this->parsedUrl['scheme'] != 'https' ) {
                        $this->status->fatal( 'http-invalid-scheme', $this->parsedUrl['scheme'] );
                }

                $this->reqHeaders['Accept'] = "*/*";
                $this->reqHeaders['Connection'] = 'Close';
                if ( $this->method == 'POST' ) {
                        // Required for HTTP 1.0 POSTs
                        $this->reqHeaders['Content-Length'] = strlen( $this->postData );
                        if ( !isset( $this->reqHeaders['Content-Type'] ) ) {
                                $this->reqHeaders['Content-Type'] = "application/x-www-form-urlencoded";
                        }
                }

                // Set up PHP stream context
                $options = [
                        'http' => [
                                'method' => $this->method,
                                'header' => implode( "\r\n", $this->getHeaderList() ),
                                'protocol_version' => '1.1',
                                'max_redirects' => $this->followRedirects ? $this->maxRedirects : 0,
                                'ignore_errors' => true,
                                'timeout' => $this->timeout,
                                // Curl options in case curlwrappers are installed
                                'curl_verify_ssl_host' => $this->sslVerifyHost ? 2 : 0,
                                'curl_verify_ssl_peer' => $this->sslVerifyCert,
                        ],
                        'ssl' => [
                                'verify_peer' => $this->sslVerifyCert,
                                'SNI_enabled' => true,
                                'ciphers' => 'HIGH:!SSLv2:!SSLv3:-ADH:-kDH:-kECDH:-DSS',
                                'disable_compression' => true,
                        ],
                ];

                if ( $this->proxy ) {
                        $options['http']['proxy'] = $this->urlToTCP( $this->proxy );
                        $options['http']['request_fulluri'] = true;
                }

                if ( $this->postData ) {
                        $options['http']['content'] = $this->postData;
                }

                if ( $this->sslVerifyHost ) {
                        // PHP 5.6.0 deprecates CN_match, in favour of peer_name which
                        // actually checks SubjectAltName properly.
                        if ( version_compare( PHP_VERSION, '5.6.0', '>=' ) ) {
                                $options['ssl']['peer_name'] = $this->parsedUrl['host'];
                        } else {
                                $options['ssl']['CN_match'] = $this->parsedUrl['host'];
                        }
                }

                $options['ssl'] += $this->getCertOptions();

                $context = stream_context_create( $options );

                $this->headerList = [];
                $reqCount = 0;
                $url = $this->url;

                $result = [];

                if ( $this->profiler ) {
                        $profileSection = $this->profiler->scopedProfileIn(
                                __METHOD__ . '-' . $this->profileName
                        );
                }
                do {
                        $reqCount++;
                        $this->fopenErrors = [];
                        set_error_handler( [ $this, 'errorHandler' ] );
                        $fh = fopen( $url, "r", false, $context );
                        restore_error_handler();

                        if ( !$fh ) {
                                // HACK for instant commons.
                                // If we are contacting (commons|upload).wikimedia.org
                                // try again with CN_match for en.wikipedia.org
                                // as php does not handle SubjectAltName properly
                                // prior to "peer_name" option in php 5.6
                                if ( isset( $options['ssl']['CN_match'] )
                                        && ( $options['ssl']['CN_match'] === 'commons.wikimedia.org'
                                                || $options['ssl']['CN_match'] === 'upload.wikimedia.org' )
                                ) {
                                        $options['ssl']['CN_match'] = 'en.wikipedia.org';
                                        $context = stream_context_create( $options );
                                        continue;
                                }
                                break;
                        }

                        $result = stream_get_meta_data( $fh );
                        $this->headerList = $result['wrapper_data'];
                        $this->parseHeader();

                        if ( !$this->followRedirects ) {
                                break;
                        }

                        # Handle manual redirection
                        if ( !$this->isRedirect() || $reqCount > $this->maxRedirects ) {
                                break;
                        }
                        # Check security of URL
                        $url = $this->getResponseHeader( "Location" );

                        if ( !Http::isValidURI( $url ) ) {
                                wfDebug( __METHOD__ . ": insecure redirection\n" );
                                break;
                        }
                } while ( true );
                if ( $this->profiler ) {
                        $this->profiler->scopedProfileOut( $profileSection );
                }

                $this->setStatus();

                if ( $fh === false ) {
                        if ( $this->fopenErrors ) {
                                LoggerFactory::getInstance( 'http' )->warning( __CLASS__
                                        . ': error opening connection: {errstr1}', $this->fopenErrors );
                        }
                        $this->status->fatal( 'http-request-error' );
                        return $this->status;
                }

                if ( $result['timed_out'] ) {
                        $this->status->fatal( 'http-timed-out', $this->url );
                        return $this->status;
                }

                // If everything went OK, or we received some error code
                // get the response body content.
                if ( $this->status->isOK() || (int)$this->respStatus >= 300 ) {
                        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 );
                                }
                        }
                }
                fclose( $fh );

                return $this->status;
        }
}