includes/HttpFunctions.php

   1 <?php
   2 /**
   3  * Various HTTP related functions.
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 2 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License along
  16  * with this program; if not, write to the Free Software Foundation, Inc.,
  17  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  18  * http://www.gnu.org/copyleft/gpl.html
  19  *
  20  * @file
  21  * @ingroup HTTP
  22  */
  23
  24 /**
  25  * @defgroup HTTP HTTP
  26  */
  27
  28 use MediaWiki\Logger\LoggerFactory;
  29
  30 /**
  31  * Various HTTP related functions
  32  * @ingroup HTTP
  33  */
  34 class Http {
  35         static public $httpEngine = false;
  36
  37         /**
  38          * Perform an HTTP request
  39          *
  40          * @param string $method HTTP method. Usually GET/POST
  41          * @param string $url Full URL to act on. If protocol-relative, will be expanded to an http:// URL
  42          * @param array $options Options to pass to MWHttpRequest object.
  43          *      Possible keys for the array:
  44          *    - timeout             Timeout length in seconds
  45          *    - connectTimeout      Timeout for connection, in seconds (curl only)
  46          *    - postData            An array of key-value pairs or a url-encoded form data
  47          *    - proxy               The proxy to use.
  48          *                          Otherwise it will use $wgHTTPProxy (if set)
  49          *                          Otherwise it will use the environment variable "http_proxy" (if set)
  50          *    - noProxy             Don't use any proxy at all. Takes precedence over proxy value(s).
  51          *    - sslVerifyHost       Verify hostname against certificate
  52          *    - sslVerifyCert       Verify SSL certificate
  53          *    - caInfo              Provide CA information
  54          *    - maxRedirects        Maximum number of redirects to follow (defaults to 5)
  55          *    - followRedirects     Whether to follow redirects (defaults to false).
  56          *                                  Note: this should only be used when the target URL is trusted,
  57          *                                  to avoid attacks on intranet services accessible by HTTP.
  58          *    - userAgent           A user agent, if you want to override the default
  59          *                          MediaWiki/$wgVersion
  60          * @param string $caller The method making this request, for profiling
  61          * @return string|bool (bool)false on failure or a string on success
  62          */
  63         public static function request( $method, $url, $options = [], $caller = __METHOD__ ) {
  64                 wfDebug( "HTTP: $method: $url\n" );
  65
  66                 $options['method'] = strtoupper( $method );
  67
  68                 if ( !isset( $options['timeout'] ) ) {
  69                         $options['timeout'] = 'default';
  70                 }
  71                 if ( !isset( $options['connectTimeout'] ) ) {
  72                         $options['connectTimeout'] = 'default';
  73                 }
  74
  75                 $req = MWHttpRequest::factory( $url, $options, $caller );
  76                 $status = $req->execute();
  77
  78                 if ( $status->isOK() ) {
  79                         return $req->getContent();
  80                 } else {
  81                         $errors = $status->getErrorsByType( 'error' );
  82                         $logger = LoggerFactory::getInstance( 'http' );
  83                         $logger->warning( $status->getWikiText( null, null, 'en' ),
  84                                 [ 'error' => $errors, 'caller' => $caller, 'content' => $req->getContent() ] );
  85                         return false;
  86                 }
  87         }
  88
  89         /**
  90          * Simple wrapper for Http::request( 'GET' )
  91          * @see Http::request()
  92          * @since 1.25 Second parameter $timeout removed. Second parameter
  93          * is now $options which can be given a 'timeout'
  94          *
  95          * @param string $url
  96          * @param array $options
  97          * @param string $caller The method making this request, for profiling
  98          * @return string|bool false on error
  99          */
 100         public static function get( $url, $options = [], $caller = __METHOD__ ) {
 101                 $args = func_get_args();
 102                 if ( isset( $args[1] ) && ( is_string( $args[1] ) || is_numeric( $args[1] ) ) ) {
 103                         // Second was used to be the timeout
 104                         // And third parameter used to be $options
 105                         wfWarn( "Second parameter should not be a timeout.", 2 );
 106                         $options = isset( $args[2] ) && is_array( $args[2] ) ?
 107                                 $args[2] : [];
 108                         $options['timeout'] = $args[1];
 109                         $caller = __METHOD__;
 110                 }
 111                 return Http::request( 'GET', $url, $options, $caller );
 112         }
 113
 114         /**
 115          * Simple wrapper for Http::request( 'POST' )
 116          * @see Http::request()
 117          *
 118          * @param string $url
 119          * @param array $options
 120          * @param string $caller The method making this request, for profiling
 121          * @return string|bool false on error
 122          */
 123         public static function post( $url, $options = [], $caller = __METHOD__ ) {
 124                 return Http::request( 'POST', $url, $options, $caller );
 125         }
 126
 127         /**
 128          * Check if the URL can be served by localhost
 129          *
 130          * @param string $url Full url to check
 131          * @return bool
 132          */
 133         public static function isLocalURL( $url ) {
 134                 global $wgCommandLineMode, $wgLocalVirtualHosts;
 135
 136                 if ( $wgCommandLineMode ) {
 137                         return false;
 138                 }
 139
 140                 // Extract host part
 141                 $matches = [];
 142                 if ( preg_match( '!^http://([\w.-]+)[/:].*$!', $url, $matches ) ) {
 143                         $host = $matches[1];
 144                         // Split up dotwise
 145                         $domainParts = explode( '.', $host );
 146                         // Check if this domain or any superdomain is listed as a local virtual host
 147                         $domainParts = array_reverse( $domainParts );
 148
 149                         $domain = '';
 150                         $countParts = count( $domainParts );
 151                         for ( $i = 0; $i < $countParts; $i++ ) {
 152                                 $domainPart = $domainParts[$i];
 153                                 if ( $i == 0 ) {
 154                                         $domain = $domainPart;
 155                                 } else {
 156                                         $domain = $domainPart . '.' . $domain;
 157                                 }
 158
 159                                 if ( in_array( $domain, $wgLocalVirtualHosts ) ) {
 160                                         return true;
 161                                 }
 162                         }
 163                 }
 164
 165                 return false;
 166         }
 167
 168         /**
 169          * A standard user-agent we can use for external requests.
 170          * @return string
 171          */
 172         public static function userAgent() {
 173                 global $wgVersion;
 174                 return "MediaWiki/$wgVersion";
 175         }
 176
 177         /**
 178          * Checks that the given URI is a valid one. Hardcoding the
 179          * protocols, because we only want protocols that both cURL
 180          * and php support.
 181          *
 182          * file:// should not be allowed here for security purpose (r67684)
 183          *
 184          * @todo FIXME this is wildly inaccurate and fails to actually check most stuff
 185          *
 186          * @param string $uri URI to check for validity
 187          * @return bool
 188          */
 189         public static function isValidURI( $uri ) {
 190                 return preg_match(
 191                         '/^https?:\/\/[^\/\s]\S*$/D',
 192                         $uri
 193                 );
 194         }
 195
 196         /**
 197          * Gets the relevant proxy from $wgHTTPProxy/http_proxy (when set).
 198          *
 199          * @return mixed The proxy address or an empty string if not set.
 200          */
 201         public static function getProxy() {
 202                 global $wgHTTPProxy;
 203
 204                 if ( $wgHTTPProxy ) {
 205                         return $wgHTTPProxy;
 206                 }
 207
 208                 $envHttpProxy = getenv( "http_proxy" );
 209                 if ( $envHttpProxy ) {
 210                         return $envHttpProxy;
 211                 }
 212
 213                 return "";
 214         }
 215 }
 216
 217 /**
 218  * This wrapper class will call out to curl (if available) or fallback
 219  * to regular PHP if necessary for handling internal HTTP requests.
 220  *
 221  * Renamed from HttpRequest to MWHttpRequest to avoid conflict with
 222  * PHP's HTTP extension.
 223  */
 224 class MWHttpRequest {
 225         const SUPPORTS_FILE_POSTS = false;
 226
 227         protected $content;
 228         protected $timeout = 'default';
 229         protected $headersOnly = null;
 230         protected $postData = null;
 231         protected $proxy = null;
 232         protected $noProxy = false;
 233         protected $sslVerifyHost = true;
 234         protected $sslVerifyCert = true;
 235         protected $caInfo = null;
 236         protected $method = "GET";
 237         protected $reqHeaders = [];
 238         protected $url;
 239         protected $parsedUrl;
 240         protected $callback;
 241         protected $maxRedirects = 5;
 242         protected $followRedirects = false;
 243
 244         /**
 245          * @var CookieJar
 246          */
 247         protected $cookieJar;
 248
 249         protected $headerList = [];
 250         protected $respVersion = "0.9";
 251         protected $respStatus = "200 Ok";
 252         protected $respHeaders = [];
 253
 254         public $status;
 255
 256         /**
 257          * @var Profiler
 258          */
 259         protected $profiler;
 260
 261         /**
 262          * @var string
 263          */
 264         protected $profileName;
 265
 266         /**
 267          * @param string $url Url to use. If protocol-relative, will be expanded to an http:// URL
 268          * @param array $options (optional) extra params to pass (see Http::request())
 269          * @param string $caller The method making this request, for profiling
 270          * @param Profiler $profiler An instance of the profiler for profiling, or null
 271          */
 272         protected function __construct(
 273                 $url, $options = [], $caller = __METHOD__, $profiler = null
 274         ) {
 275                 global $wgHTTPTimeout, $wgHTTPConnectTimeout;
 276
 277                 $this->url = wfExpandUrl( $url, PROTO_HTTP );
 278                 $this->parsedUrl = wfParseUrl( $this->url );
 279
 280                 if ( !$this->parsedUrl || !Http::isValidURI( $this->url ) ) {
 281                         $this->status = Status::newFatal( 'http-invalid-url', $url );
 282                 } else {
 283                         $this->status = Status::newGood( 100 ); // continue
 284                 }
 285
 286                 if ( isset( $options['timeout'] ) && $options['timeout'] != 'default' ) {
 287                         $this->timeout = $options['timeout'];
 288                 } else {
 289                         $this->timeout = $wgHTTPTimeout;
 290                 }
 291                 if ( isset( $options['connectTimeout'] ) && $options['connectTimeout'] != 'default' ) {
 292                         $this->connectTimeout = $options['connectTimeout'];
 293                 } else {
 294                         $this->connectTimeout = $wgHTTPConnectTimeout;
 295                 }
 296                 if ( isset( $options['userAgent'] ) ) {
 297                         $this->setUserAgent( $options['userAgent'] );
 298                 }
 299
 300                 $members = [ "postData", "proxy", "noProxy", "sslVerifyHost", "caInfo",
 301                                 "method", "followRedirects", "maxRedirects", "sslVerifyCert", "callback" ];
 302
 303                 foreach ( $members as $o ) {
 304                         if ( isset( $options[$o] ) ) {
 305                                 // ensure that MWHttpRequest::method is always
 306                                 // uppercased. Bug 36137
 307                                 if ( $o == 'method' ) {
 308                                         $options[$o] = strtoupper( $options[$o] );
 309                                 }
 310                                 $this->$o = $options[$o];
 311                         }
 312                 }
 313
 314                 if ( $this->noProxy ) {
 315                         $this->proxy = ''; // noProxy takes precedence
 316                 }
 317
 318                 // Profile based on what's calling us
 319                 $this->profiler = $profiler;
 320                 $this->profileName = $caller;
 321         }
 322
 323         /**
 324          * Simple function to test if we can make any sort of requests at all, using
 325          * cURL or fopen()
 326          * @return bool
 327          */
 328         public static function canMakeRequests() {
 329                 return function_exists( 'curl_init' ) || wfIniGetBool( 'allow_url_fopen' );
 330         }
 331
 332         /**
 333          * Generate a new request object
 334          * @param string $url Url to use
 335          * @param array $options (optional) extra params to pass (see Http::request())
 336          * @param string $caller The method making this request, for profiling
 337          * @throws MWException
 338          * @return CurlHttpRequest|PhpHttpRequest
 339          * @see MWHttpRequest::__construct
 340          */
 341         public static function factory( $url, $options = null, $caller = __METHOD__ ) {
 342                 if ( !Http::$httpEngine ) {
 343                         Http::$httpEngine = function_exists( 'curl_init' ) ? 'curl' : 'php';
 344                 } elseif ( Http::$httpEngine == 'curl' && !function_exists( 'curl_init' ) ) {
 345                         throw new MWException( __METHOD__ . ': curl (http://php.net/curl) is not installed, but' .
 346                                 ' Http::$httpEngine is set to "curl"' );
 347                 }
 348
 349                 switch ( Http::$httpEngine ) {
 350                         case 'curl':
 351                                 return new CurlHttpRequest( $url, $options, $caller, Profiler::instance() );
 352                         case 'php':
 353                                 if ( !wfIniGetBool( 'allow_url_fopen' ) ) {
 354                                         throw new MWException( __METHOD__ . ': allow_url_fopen ' .
 355                                                 'needs to be enabled for pure PHP http requests to ' .
 356                                                 'work. If possible, curl should be used instead. See ' .
 357                                                 'http://php.net/curl.'
 358                                         );
 359                                 }
 360                                 return new PhpHttpRequest( $url, $options, $caller, Profiler::instance() );
 361                         default:
 362                                 throw new MWException( __METHOD__ . ': The setting of Http::$httpEngine is not valid.' );
 363                 }
 364         }
 365
 366         /**
 367          * Get the body, or content, of the response to the request
 368          *
 369          * @return string
 370          */
 371         public function getContent() {
 372                 return $this->content;
 373         }
 374
 375         /**
 376          * Set the parameters of the request
 377          *
 378          * @param array $args
 379          * @todo overload the args param
 380          */
 381         public function setData( $args ) {
 382                 $this->postData = $args;
 383         }
 384
 385         /**
 386          * Take care of setting up the proxy (do nothing if "noProxy" is set)
 387          *
 388          * @return void
 389          */
 390         public function proxySetup() {
 391                 // If there is an explicit proxy set and proxies are not disabled, then use it
 392                 if ( $this->proxy && !$this->noProxy ) {
 393                         return;
 394                 }
 395
 396                 // Otherwise, fallback to $wgHTTPProxy/http_proxy (when set) if this is not a machine
 397                 // local URL and proxies are not disabled
 398                 if ( Http::isLocalURL( $this->url ) || $this->noProxy ) {
 399                         $this->proxy = '';
 400                 } else {
 401                         $this->proxy = Http::getProxy();
 402                 }
 403         }
 404
 405         /**
 406          * Set the user agent
 407          * @param string $UA
 408          */
 409         public function setUserAgent( $UA ) {
 410                 $this->setHeader( 'User-Agent', $UA );
 411         }
 412
 413         /**
 414          * Set an arbitrary header
 415          * @param string $name
 416          * @param string $value
 417          */
 418         public function setHeader( $name, $value ) {
 419                 // I feel like I should normalize the case here...
 420                 $this->reqHeaders[$name] = $value;
 421         }
 422
 423         /**
 424          * Get an array of the headers
 425          * @return array
 426          */
 427         public function getHeaderList() {
 428                 $list = [];
 429
 430                 if ( $this->cookieJar ) {
 431                         $this->reqHeaders['Cookie'] =
 432                                 $this->cookieJar->serializeToHttpRequest(
 433                                         $this->parsedUrl['path'],
 434                                         $this->parsedUrl['host']
 435                                 );
 436                 }
 437
 438                 foreach ( $this->reqHeaders as $name => $value ) {
 439                         $list[] = "$name: $value";
 440                 }
 441
 442                 return $list;
 443         }
 444
 445         /**
 446          * Set a read callback to accept data read from the HTTP request.
 447          * By default, data is appended to an internal buffer which can be
 448          * retrieved through $req->getContent().
 449          *
 450          * To handle data as it comes in -- especially for large files that
 451          * would not fit in memory -- you can instead set your own callback,
 452          * in the form function($resource, $buffer) where the first parameter
 453          * is the low-level resource being read (implementation specific),
 454          * and the second parameter is the data buffer.
 455          *
 456          * You MUST return the number of bytes handled in the buffer; if fewer
 457          * bytes are reported handled than were passed to you, the HTTP fetch
 458          * will be aborted.
 459          *
 460          * @param callable $callback
 461          * @throws MWException
 462          */
 463         public function setCallback( $callback ) {
 464                 if ( !is_callable( $callback ) ) {
 465                         throw new MWException( 'Invalid MwHttpRequest callback' );
 466                 }
 467                 $this->callback = $callback;
 468         }
 469
 470         /**
 471          * A generic callback to read the body of the response from a remote
 472          * server.
 473          *
 474          * @param resource $fh
 475          * @param string $content
 476          * @return int
 477          */
 478         public function read( $fh, $content ) {
 479                 $this->content .= $content;
 480                 return strlen( $content );
 481         }
 482
 483         /**
 484          * Take care of whatever is necessary to perform the URI request.
 485          *
 486          * @return Status
 487          */
 488         public function execute() {
 489
 490                 $this->content = "";
 491
 492                 if ( strtoupper( $this->method ) == "HEAD" ) {
 493                         $this->headersOnly = true;
 494                 }
 495
 496                 $this->proxySetup(); // set up any proxy as needed
 497
 498                 if ( !$this->callback ) {
 499                         $this->setCallback( [ $this, 'read' ] );
 500                 }
 501
 502                 if ( !isset( $this->reqHeaders['User-Agent'] ) ) {
 503                         $this->setUserAgent( Http::userAgent() );
 504                 }
 505
 506         }
 507
 508         /**
 509          * Parses the headers, including the HTTP status code and any
 510          * Set-Cookie headers.  This function expects the headers to be
 511          * found in an array in the member variable headerList.
 512          */
 513         protected function parseHeader() {
 514
 515                 $lastname = "";
 516
 517                 foreach ( $this->headerList as $header ) {
 518                         if ( preg_match( "#^HTTP/([0-9.]+) (.*)#", $header, $match ) ) {
 519                                 $this->respVersion = $match[1];
 520                                 $this->respStatus = $match[2];
 521                         } elseif ( preg_match( "#^[ \t]#", $header ) ) {
 522                                 $last = count( $this->respHeaders[$lastname] ) - 1;
 523                                 $this->respHeaders[$lastname][$last] .= "\r\n$header";
 524                         } elseif ( preg_match( "#^([^:]*):[\t ]*(.*)#", $header, $match ) ) {
 525                                 $this->respHeaders[strtolower( $match[1] )][] = $match[2];
 526                                 $lastname = strtolower( $match[1] );
 527                         }
 528                 }
 529
 530                 $this->parseCookies();
 531
 532         }
 533
 534         /**
 535          * Sets HTTPRequest status member to a fatal value with the error
 536          * message if the returned integer value of the status code was
 537          * not successful (< 300) or a redirect (>=300 and < 400).  (see
 538          * RFC2616, section 10,
 539          * http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html for a
 540          * list of status codes.)
 541          */
 542         protected function setStatus() {
 543                 if ( !$this->respHeaders ) {
 544                         $this->parseHeader();
 545                 }
 546
 547                 if ( (int)$this->respStatus > 399 ) {
 548                         list( $code, $message ) = explode( " ", $this->respStatus, 2 );
 549                         $this->status->fatal( "http-bad-status", $code, $message );
 550                 }
 551         }
 552
 553         /**
 554          * Get the integer value of the HTTP status code (e.g. 200 for "200 Ok")
 555          * (see RFC2616, section 10, http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html
 556          * for a list of status codes.)
 557          *
 558          * @return int
 559          */
 560         public function getStatus() {
 561                 if ( !$this->respHeaders ) {
 562                         $this->parseHeader();
 563                 }
 564
 565                 return (int)$this->respStatus;
 566         }
 567
 568         /**
 569          * Returns true if the last status code was a redirect.
 570          *
 571          * @return bool
 572          */
 573         public function isRedirect() {
 574                 if ( !$this->respHeaders ) {
 575                         $this->parseHeader();
 576                 }
 577
 578                 $status = (int)$this->respStatus;
 579
 580                 if ( $status >= 300 && $status <= 303 ) {
 581                         return true;
 582                 }
 583
 584                 return false;
 585         }
 586
 587         /**
 588          * Returns an associative array of response headers after the
 589          * request has been executed.  Because some headers
 590          * (e.g. Set-Cookie) can appear more than once the, each value of
 591          * the associative array is an array of the values given.
 592          *
 593          * @return array
 594          */
 595         public function getResponseHeaders() {
 596                 if ( !$this->respHeaders ) {
 597                         $this->parseHeader();
 598                 }
 599
 600                 return $this->respHeaders;
 601         }
 602
 603         /**
 604          * Returns the value of the given response header.
 605          *
 606          * @param string $header
 607          * @return string
 608          */
 609         public function getResponseHeader( $header ) {
 610                 if ( !$this->respHeaders ) {
 611                         $this->parseHeader();
 612                 }
 613
 614                 if ( isset( $this->respHeaders[strtolower( $header )] ) ) {
 615                         $v = $this->respHeaders[strtolower( $header )];
 616                         return $v[count( $v ) - 1];
 617                 }
 618
 619                 return null;
 620         }
 621
 622         /**
 623          * Tells the MWHttpRequest object to use this pre-loaded CookieJar.
 624          *
 625          * @param CookieJar $jar
 626          */
 627         public function setCookieJar( $jar ) {
 628                 $this->cookieJar = $jar;
 629         }
 630
 631         /**
 632          * Returns the cookie jar in use.
 633          *
 634          * @return CookieJar
 635          */
 636         public function getCookieJar() {
 637                 if ( !$this->respHeaders ) {
 638                         $this->parseHeader();
 639                 }
 640
 641                 return $this->cookieJar;
 642         }
 643
 644         /**
 645          * Sets a cookie. Used before a request to set up any individual
 646          * cookies. Used internally after a request to parse the
 647          * Set-Cookie headers.
 648          * @see Cookie::set
 649          * @param string $name
 650          * @param mixed $value
 651          * @param array $attr
 652          */
 653         public function setCookie( $name, $value = null, $attr = null ) {
 654                 if ( !$this->cookieJar ) {
 655                         $this->cookieJar = new CookieJar;
 656                 }
 657
 658                 $this->cookieJar->setCookie( $name, $value, $attr );
 659         }
 660
 661         /**
 662          * Parse the cookies in the response headers and store them in the cookie jar.
 663          */
 664         protected function parseCookies() {
 665
 666                 if ( !$this->cookieJar ) {
 667                         $this->cookieJar = new CookieJar;
 668                 }
 669
 670                 if ( isset( $this->respHeaders['set-cookie'] ) ) {
 671                         $url = parse_url( $this->getFinalUrl() );
 672                         foreach ( $this->respHeaders['set-cookie'] as $cookie ) {
 673                                 $this->cookieJar->parseCookieResponseHeader( $cookie, $url['host'] );
 674                         }
 675                 }
 676
 677         }
 678
 679         /**
 680          * Returns the final URL after all redirections.
 681          *
 682          * Relative values of the "Location" header are incorrect as
 683          * stated in RFC, however they do happen and modern browsers
 684          * support them.  This function loops backwards through all
 685          * locations in order to build the proper absolute URI - Marooned
 686          * at wikia-inc.com
 687          *
 688          * Note that the multiple Location: headers are an artifact of
 689          * CURL -- they shouldn't actually get returned this way. Rewrite
 690          * this when bug 29232 is taken care of (high-level redirect
 691          * handling rewrite).
 692          *
 693          * @return string
 694          */
 695         public function getFinalUrl() {
 696                 $headers = $this->getResponseHeaders();
 697
 698                 // return full url (fix for incorrect but handled relative location)
 699                 if ( isset( $headers['location'] ) ) {
 700                         $locations = $headers['location'];
 701                         $domain = '';
 702                         $foundRelativeURI = false;
 703                         $countLocations = count( $locations );
 704
 705                         for ( $i = $countLocations - 1; $i >= 0; $i-- ) {
 706                                 $url = parse_url( $locations[$i] );
 707
 708                                 if ( isset( $url['host'] ) ) {
 709                                         $domain = $url['scheme'] . '://' . $url['host'];
 710                                         break; // found correct URI (with host)
 711                                 } else {
 712                                         $foundRelativeURI = true;
 713                                 }
 714                         }
 715
 716                         if ( $foundRelativeURI ) {
 717                                 if ( $domain ) {
 718                                         return $domain . $locations[$countLocations - 1];
 719                                 } else {
 720                                         $url = parse_url( $this->url );
 721                                         if ( isset( $url['host'] ) ) {
 722                                                 return $url['scheme'] . '://' . $url['host'] .
 723                                                         $locations[$countLocations - 1];
 724                                         }
 725                                 }
 726                         } else {
 727                                 return $locations[$countLocations - 1];
 728                         }
 729                 }
 730
 731                 return $this->url;
 732         }
 733
 734         /**
 735          * Returns true if the backend can follow redirects. Overridden by the
 736          * child classes.
 737          * @return bool
 738          */
 739         public function canFollowRedirects() {
 740                 return true;
 741         }
 742 }
 743
 744 /**
 745  * MWHttpRequest implemented using internal curl compiled into PHP
 746  */
 747 class CurlHttpRequest extends MWHttpRequest {
 748         const SUPPORTS_FILE_POSTS = true;
 749
 750         protected $curlOptions = [];
 751         protected $headerText = "";
 752
 753         /**
 754          * @param resource $fh
 755          * @param string $content
 756          * @return int
 757          */
 758         protected function readHeader( $fh, $content ) {
 759                 $this->headerText .= $content;
 760                 return strlen( $content );
 761         }
 762
 763         public function execute() {
 764
 765                 parent::execute();
 766
 767                 if ( !$this->status->isOK() ) {
 768                         return $this->status;
 769                 }
 770
 771                 $this->curlOptions[CURLOPT_PROXY] = $this->proxy;
 772                 $this->curlOptions[CURLOPT_TIMEOUT] = $this->timeout;
 773
 774                 // Only supported in curl >= 7.16.2
 775                 if ( defined( 'CURLOPT_CONNECTTIMEOUT_MS' ) ) {
 776                         $this->curlOptions[CURLOPT_CONNECTTIMEOUT_MS] = $this->connectTimeout * 1000;
 777                 }
 778
 779                 $this->curlOptions[CURLOPT_HTTP_VERSION] = CURL_HTTP_VERSION_1_0;
 780                 $this->curlOptions[CURLOPT_WRITEFUNCTION] = $this->callback;
 781                 $this->curlOptions[CURLOPT_HEADERFUNCTION] = [ $this, "readHeader" ];
 782                 $this->curlOptions[CURLOPT_MAXREDIRS] = $this->maxRedirects;
 783                 $this->curlOptions[CURLOPT_ENCODING] = ""; # Enable compression
 784
 785                 $this->curlOptions[CURLOPT_USERAGENT] = $this->reqHeaders['User-Agent'];
 786
 787                 $this->curlOptions[CURLOPT_SSL_VERIFYHOST] = $this->sslVerifyHost ? 2 : 0;
 788                 $this->curlOptions[CURLOPT_SSL_VERIFYPEER] = $this->sslVerifyCert;
 789
 790                 if ( $this->caInfo ) {
 791                         $this->curlOptions[CURLOPT_CAINFO] = $this->caInfo;
 792                 }
 793
 794                 if ( $this->headersOnly ) {
 795                         $this->curlOptions[CURLOPT_NOBODY] = true;
 796                         $this->curlOptions[CURLOPT_HEADER] = true;
 797                 } elseif ( $this->method == 'POST' ) {
 798                         $this->curlOptions[CURLOPT_POST] = true;
 799                         $postData = $this->postData;
 800                         // Don't interpret POST parameters starting with '@' as file uploads, because this
 801                         // makes it impossible to POST plain values starting with '@' (and causes security
 802                         // issues potentially exposing the contents of local files).
 803                         // The PHP manual says this option was introduced in PHP 5.5 defaults to true in PHP 5.6,
 804                         // but we support lower versions, and the option doesn't exist in HHVM 5.6.99.
 805                         if ( defined( 'CURLOPT_SAFE_UPLOAD' ) ) {
 806                                 $this->curlOptions[CURLOPT_SAFE_UPLOAD] = true;
 807                         } elseif ( is_array( $postData ) ) {
 808                                 // In PHP 5.2 and later, '@' is interpreted as a file upload if POSTFIELDS
 809                                 // is an array, but not if it's a string. So convert $req['body'] to a string
 810                                 // for safety.
 811                                 $postData = wfArrayToCgi( $postData );
 812                         }
 813                         $this->curlOptions[CURLOPT_POSTFIELDS] = $postData;
 814
 815                         // Suppress 'Expect: 100-continue' header, as some servers
 816                         // will reject it with a 417 and Curl won't auto retry
 817                         // with HTTP 1.0 fallback
 818                         $this->reqHeaders['Expect'] = '';
 819                 } else {
 820                         $this->curlOptions[CURLOPT_CUSTOMREQUEST] = $this->method;
 821                 }
 822
 823                 $this->curlOptions[CURLOPT_HTTPHEADER] = $this->getHeaderList();
 824
 825                 $curlHandle = curl_init( $this->url );
 826
 827                 if ( !curl_setopt_array( $curlHandle, $this->curlOptions ) ) {
 828                         throw new MWException( "Error setting curl options." );
 829                 }
 830
 831                 if ( $this->followRedirects && $this->canFollowRedirects() ) {
 832                         MediaWiki\suppressWarnings();
 833                         if ( !curl_setopt( $curlHandle, CURLOPT_FOLLOWLOCATION, true ) ) {
 834                                 wfDebug( __METHOD__ . ": Couldn't set CURLOPT_FOLLOWLOCATION. " .
 835                                         "Probably open_basedir is set.\n" );
 836                                 // Continue the processing. If it were in curl_setopt_array,
 837                                 // processing would have halted on its entry
 838                         }
 839                         MediaWiki\restoreWarnings();
 840                 }
 841
 842                 if ( $this->profiler ) {
 843                         $profileSection = $this->profiler->scopedProfileIn(
 844                                 __METHOD__ . '-' . $this->profileName
 845                         );
 846                 }
 847
 848                 $curlRes = curl_exec( $curlHandle );
 849                 if ( curl_errno( $curlHandle ) == CURLE_OPERATION_TIMEOUTED ) {
 850                         $this->status->fatal( 'http-timed-out', $this->url );
 851                 } elseif ( $curlRes === false ) {
 852                         $this->status->fatal( 'http-curl-error', curl_error( $curlHandle ) );
 853                 } else {
 854                         $this->headerList = explode( "\r\n", $this->headerText );
 855                 }
 856
 857                 curl_close( $curlHandle );
 858
 859                 if ( $this->profiler ) {
 860                         $this->profiler->scopedProfileOut( $profileSection );
 861                 }
 862
 863                 $this->parseHeader();
 864                 $this->setStatus();
 865
 866                 return $this->status;
 867         }
 868
 869         /**
 870          * @return bool
 871          */
 872         public function canFollowRedirects() {
 873                 $curlVersionInfo = curl_version();
 874                 if ( $curlVersionInfo['version_number'] < 0x071304 ) {
 875                         wfDebug( "Cannot follow redirects with libcurl < 7.19.4 due to CVE-2009-0037\n" );
 876                         return false;
 877                 }
 878
 879                 if ( version_compare( PHP_VERSION, '5.6.0', '<' ) ) {
 880                         if ( strval( ini_get( 'open_basedir' ) ) !== '' ) {
 881                                 wfDebug( "Cannot follow redirects when open_basedir is set\n" );
 882                                 return false;
 883                         }
 884                 }
 885
 886                 return true;
 887         }
 888 }
 889
 890 class PhpHttpRequest extends MWHttpRequest {
 891
 892         private $fopenErrors = [];
 893
 894         /**
 895          * @param string $url
 896          * @return string
 897          */
 898         protected function urlToTcp( $url ) {
 899                 $parsedUrl = parse_url( $url );
 900
 901                 return 'tcp://' . $parsedUrl['host'] . ':' . $parsedUrl['port'];
 902         }
 903
 904         /**
 905          * Returns an array with a 'capath' or 'cafile' key
 906          * that is suitable to be merged into the 'ssl' sub-array of
 907          * a stream context options array.
 908          * Uses the 'caInfo' option of the class if it is provided, otherwise uses the system
 909          * default CA bundle if PHP supports that, or searches a few standard locations.
 910          * @return array
 911          * @throws DomainException
 912          */
 913         protected function getCertOptions() {
 914                 $certOptions = [];
 915                 $certLocations = [];
 916                 if ( $this->caInfo ) {
 917                         $certLocations = [ 'manual' => $this->caInfo ];
 918                 } elseif ( version_compare( PHP_VERSION, '5.6.0', '<' ) ) {
 919                         // @codingStandardsIgnoreStart Generic.Files.LineLength
 920                         // Default locations, based on
 921                         // https://www.happyassassin.net/2015/01/12/a-note-about-ssltls-trusted-certificate-stores-and-platforms/
 922                         // PHP 5.5 and older doesn't have any defaults, so we try to guess ourselves.
 923                         // PHP 5.6+ gets the CA location from OpenSSL as long as it is not set manually,
 924                         // so we should leave capath/cafile empty there.
 925                         // @codingStandardsIgnoreEnd
 926                         $certLocations = array_filter( [
 927                                 getenv( 'SSL_CERT_DIR' ),
 928                                 getenv( 'SSL_CERT_PATH' ),
 929                                 '/etc/pki/tls/certs/ca-bundle.crt', # Fedora et al
 930                                 '/etc/ssl/certs',  # Debian et al
 931                                 '/etc/pki/tls/certs/ca-bundle.trust.crt',
 932                                 '/etc/pki/ca-trust/extracted/pem/tls-ca-bundle.pem',
 933                                 '/System/Library/OpenSSL', # OSX
 934                         ] );
 935                 }
 936
 937                 foreach ( $certLocations as $key => $cert ) {
 938                         if ( is_dir( $cert ) ) {
 939                                 $certOptions['capath'] = $cert;
 940                                 break;
 941                         } elseif ( is_file( $cert ) ) {
 942                                 $certOptions['cafile'] = $cert;
 943                                 break;
 944                         } elseif ( $key === 'manual' ) {
 945                                 // fail more loudly if a cert path was manually configured and it is not valid
 946                                 throw new DomainException( "Invalid CA info passed: $cert" );
 947                         }
 948                 }
 949
 950                 return $certOptions;
 951         }
 952
 953         /**
 954          * Custom error handler for dealing with fopen() errors.
 955          * fopen() tends to fire multiple errors in succession, and the last one
 956          * is completely useless (something like "fopen: failed to open stream")
 957          * so normal methods of handling errors programmatically
 958          * like get_last_error() don't work.
 959          */
 960         public function errorHandler( $errno, $errstr ) {
 961                 $n = count( $this->fopenErrors ) + 1;
 962                 $this->fopenErrors += [ "errno$n" => $errno, "errstr$n" => $errstr ];
 963         }
 964
 965         public function execute() {
 966
 967                 parent::execute();
 968
 969                 if ( is_array( $this->postData ) ) {
 970                         $this->postData = wfArrayToCgi( $this->postData );
 971                 }
 972
 973                 if ( $this->parsedUrl['scheme'] != 'http'
 974                         && $this->parsedUrl['scheme'] != 'https' ) {
 975                         $this->status->fatal( 'http-invalid-scheme', $this->parsedUrl['scheme'] );
 976                 }
 977
 978                 $this->reqHeaders['Accept'] = "*/*";
 979                 $this->reqHeaders['Connection'] = 'Close';
 980                 if ( $this->method == 'POST' ) {
 981                         // Required for HTTP 1.0 POSTs
 982                         $this->reqHeaders['Content-Length'] = strlen( $this->postData );
 983                         if ( !isset( $this->reqHeaders['Content-Type'] ) ) {
 984                                 $this->reqHeaders['Content-Type'] = "application/x-www-form-urlencoded";
 985                         }
 986                 }
 987
 988                 // Set up PHP stream context
 989                 $options = [
 990                         'http' => [
 991                                 'method' => $this->method,
 992                                 'header' => implode( "\r\n", $this->getHeaderList() ),
 993                                 'protocol_version' => '1.1',
 994                                 'max_redirects' => $this->followRedirects ? $this->maxRedirects : 0,
 995                                 'ignore_errors' => true,
 996                                 'timeout' => $this->timeout,
 997                                 // Curl options in case curlwrappers are installed
 998                                 'curl_verify_ssl_host' => $this->sslVerifyHost ? 2 : 0,
 999                                 'curl_verify_ssl_peer' => $this->sslVerifyCert,
1000                         ],
1001                         'ssl' => [
1002                                 'verify_peer' => $this->sslVerifyCert,
1003                                 'SNI_enabled' => true,
1004                                 'ciphers' => 'HIGH:!SSLv2:!SSLv3:-ADH:-kDH:-kECDH:-DSS',
1005                                 'disable_compression' => true,
1006                         ],
1007                 ];
1008
1009                 if ( $this->proxy ) {
1010                         $options['http']['proxy'] = $this->urlToTcp( $this->proxy );
1011                         $options['http']['request_fulluri'] = true;
1012                 }
1013
1014                 if ( $this->postData ) {
1015                         $options['http']['content'] = $this->postData;
1016                 }
1017
1018                 if ( $this->sslVerifyHost ) {
1019                         // PHP 5.6.0 deprecates CN_match, in favour of peer_name which
1020                         // actually checks SubjectAltName properly.
1021                         if ( version_compare( PHP_VERSION, '5.6.0', '>=' ) ) {
1022                                 $options['ssl']['peer_name'] = $this->parsedUrl['host'];
1023                         } else {
1024                                 $options['ssl']['CN_match'] = $this->parsedUrl['host'];
1025                         }
1026                 }
1027
1028                 $options['ssl'] += $this->getCertOptions();
1029
1030                 $context = stream_context_create( $options );
1031
1032                 $this->headerList = [];
1033                 $reqCount = 0;
1034                 $url = $this->url;
1035
1036                 $result = [];
1037
1038                 if ( $this->profiler ) {
1039                         $profileSection = $this->profiler->scopedProfileIn(
1040                                 __METHOD__ . '-' . $this->profileName
1041                         );
1042                 }
1043                 do {
1044                         $reqCount++;
1045                         $this->fopenErrors = [];
1046                         set_error_handler( [ $this, 'errorHandler' ] );
1047                         $fh = fopen( $url, "r", false, $context );
1048                         restore_error_handler();
1049
1050                         if ( !$fh ) {
1051                                 // HACK for instant commons.
1052                                 // If we are contacting (commons|upload).wikimedia.org
1053                                 // try again with CN_match for en.wikipedia.org
1054                                 // as php does not handle SubjectAltName properly
1055                                 // prior to "peer_name" option in php 5.6
1056                                 if ( isset( $options['ssl']['CN_match'] )
1057                                         && ( $options['ssl']['CN_match'] === 'commons.wikimedia.org'
1058                                                 || $options['ssl']['CN_match'] === 'upload.wikimedia.org' )
1059                                 ) {
1060                                         $options['ssl']['CN_match'] = 'en.wikipedia.org';
1061                                         $context = stream_context_create( $options );
1062                                         continue;
1063                                 }
1064                                 break;
1065                         }
1066
1067                         $result = stream_get_meta_data( $fh );
1068                         $this->headerList = $result['wrapper_data'];
1069                         $this->parseHeader();
1070
1071                         if ( !$this->followRedirects ) {
1072                                 break;
1073                         }
1074
1075                         # Handle manual redirection
1076                         if ( !$this->isRedirect() || $reqCount > $this->maxRedirects ) {
1077                                 break;
1078                         }
1079                         # Check security of URL
1080                         $url = $this->getResponseHeader( "Location" );
1081
1082                         if ( !Http::isValidURI( $url ) ) {
1083                                 wfDebug( __METHOD__ . ": insecure redirection\n" );
1084                                 break;
1085                         }
1086                 } while ( true );
1087                 if ( $this->profiler ) {
1088                         $this->profiler->scopedProfileOut( $profileSection );
1089                 }
1090
1091                 $this->setStatus();
1092
1093                 if ( $fh === false ) {
1094                         if ( $this->fopenErrors ) {
1095                                 LoggerFactory::getInstance( 'http' )->warning( __CLASS__
1096                                         . ': error opening connection: {errstr1}', $this->fopenErrors );
1097                         }
1098                         $this->status->fatal( 'http-request-error' );
1099                         return $this->status;
1100                 }
1101
1102                 if ( $result['timed_out'] ) {
1103                         $this->status->fatal( 'http-timed-out', $this->url );
1104                         return $this->status;
1105                 }
1106
1107                 // If everything went OK, or we received some error code
1108                 // get the response body content.
1109                 if ( $this->status->isOK() || (int)$this->respStatus >= 300 ) {
1110                         while ( !feof( $fh ) ) {
1111                                 $buf = fread( $fh, 8192 );
1112
1113                                 if ( $buf === false ) {
1114                                         $this->status->fatal( 'http-read-error' );
1115                                         break;
1116                                 }
1117
1118                                 if ( strlen( $buf ) ) {
1119                                         call_user_func( $this->callback, $fh, $buf );
1120                                 }
1121                         }
1122                 }
1123                 fclose( $fh );
1124
1125                 return $this->status;
1126         }
1127 }