get( $wgCaptchaFileBackend ); } else { static $backend = null; if ( !$backend ) { $backend = new FSFileBackend( array( 'name' => 'captcha-backend', 'wikiId' => wfWikiId(), 'lockManager' => new NullLockManager( array() ), 'containerPaths' => array( 'captcha-render' => $wgCaptchaDirectory ), 'fileMode' => 777 ) ); } return $backend; } } /** * @return integer Estimate of the number of captchas files */ public function estimateCaptchaCount() { global $wgCaptchaDirectoryLevels; $factor = 1; $sampleDir = $this->getBackend()->getRootStoragePath() . '/captcha-render'; if ( $wgCaptchaDirectoryLevels >= 1 ) { // 1/16 sample if 16 shards $sampleDir .= '/' . dechex( mt_rand( 0, 15 ) ); $factor = 16; } if ( $wgCaptchaDirectoryLevels >= 3 ) { // 1/256 sample if 4096 shards $sampleDir .= '/' . dechex( mt_rand( 0, 15 ) ); $factor = 256; } $count = 0; foreach ( $this->getBackend()->getFileList( array( 'dir' => $sampleDir ) ) as $file ) { ++$count; } return ( $count * $factor ); } /** * Check if the submitted form matches the captcha session data provided * by the plugin when the form was generated. * * @param string $answer * @param array $info * @return bool */ function keyMatch( $answer, $info ) { global $wgCaptchaSecret; $digest = $wgCaptchaSecret . $info['salt'] . $answer . $wgCaptchaSecret . $info['salt']; $answerHash = substr( md5( $digest ), 0, 16 ); if ( $answerHash == $info['hash'] ) { wfDebug( "FancyCaptcha: answer hash matches expected {$info['hash']}\n" ); return true; } else { wfDebug( "FancyCaptcha: answer hashes to $answerHash, expected {$info['hash']}\n" ); return false; } } function addCaptchaAPI( &$resultArr ) { $info = $this->pickImage(); if ( !$info ) { $resultArr['captcha']['error'] = 'Out of images'; return; } $index = $this->storeCaptcha( $info ); $title = SpecialPage::getTitleFor( 'Captcha', 'image' ); $resultArr['captcha']['type'] = 'image'; $resultArr['captcha']['mime'] = 'image/png'; $resultArr['captcha']['id'] = $index; $resultArr['captcha']['url'] = $title->getLocalUrl( 'wpCaptchaId=' . urlencode( $index ) ); } /** * Insert the captcha prompt into the edit form. */ function getForm() { global $wgOut, $wgExtensionAssetsPath, $wgEnableAPI; // Uses addModuleStyles so it is loaded when JS is disabled. $wgOut->addModuleStyles( 'ext.confirmEdit.fancyCaptcha.styles' ); $title = SpecialPage::getTitleFor( 'Captcha', 'image' ); $index = $this->getCaptchaIndex(); if ( $wgEnableAPI ) { // Loaded only if JS is enabled $wgOut->addModules( 'ext.confirmEdit.fancyCaptcha' ); $captchaReload = Html::element( 'small', array( 'class' => 'confirmedit-captcha-reload fancycaptcha-reload' ), wfMessage( 'fancycaptcha-reload-text' )->text() ); } else { $captchaReload = ''; } return "

" . Html::element( 'img', array( 'class' => 'fancycaptcha-image', 'src' => $title->getLocalUrl( 'wpCaptchaId=' . urlencode( $index ) ), 'alt' => '' ) ) . $captchaReload . "

\n" . '

' . Html::element( 'label', array( 'for' => 'wpCaptchaWord', ), parent::getMessage( 'label' ) . wfMessage( 'colon-separator' )->text() ) . Html::element( 'input', array( 'name' => 'wpCaptchaWord', 'id' => 'wpCaptchaWord', 'type' => 'text', 'size' => '12', // max_length in captcha.py plus fudge factor 'autocomplete' => 'off', 'autocorrect' => 'off', 'autocapitalize' => 'off', 'required' => 'required', 'tabindex' => 1 ) ) . // tab in before the edit textarea Html::element( 'input', array( 'type' => 'hidden', 'name' => 'wpCaptchaId', 'id' => 'wpCaptchaId', 'value' => $index ) ) . "

\n" . "

\n";; } /** * Get captcha index key * @return string captcha ID key */ function getCaptchaIndex() { $info = $this->pickImage(); if ( !$info ) { throw new MWException( "Ran out of captcha images" ); } // Generate a random key for use of this captcha image in this session. // This is needed so multiple edits in separate tabs or windows can // go through without extra pain. $index = $this->storeCaptcha( $info ); return $index; } /** * Select a previously generated captcha image from the queue. * @return mixed tuple of (salt key, text hash) or false if no image to find */ protected function pickImage() { global $wgCaptchaDirectoryLevels; $lockouts = 0; // number of times another process claimed a file before this one $baseDir = $this->getBackend()->getRootStoragePath() . '/captcha-render'; return $this->pickImageDir( $baseDir, $wgCaptchaDirectoryLevels, $lockouts ); } /** * @param $directory string * @param $levels integer * @param $lockouts integer * @return Array|bool */ protected function pickImageDir( $directory, $levels, &$lockouts ) { global $wgMemc; if ( $levels <= 0 ) { // $directory has regular files return $this->pickImageFromDir( $directory, $lockouts ); } $backend = $this->getBackend(); $key = "fancycaptcha:dirlist:{$backend->getWikiId()}:" . sha1( $directory ); $dirs = $wgMemc->get( $key ); // check cache if ( !is_array( $dirs ) || !count( $dirs ) ) { // cache miss $dirs = array(); // subdirs actually present... foreach ( $backend->getTopDirectoryList( array( 'dir' => $directory ) ) as $entry ) { if ( ctype_xdigit( $entry ) && strlen( $entry ) == 1 ) { $dirs[] = $entry; } } wfDebug( "Cache miss for $directory subdirectory listing.\n" ); if ( count( $dirs ) ) { $wgMemc->set( $key, $dirs, 86400 ); } } if ( !count( $dirs ) ) { // Remove this directory if empty so callers don't keep looking here $backend->clean( array( 'dir' => $directory ) ); return false; // none found } $place = mt_rand( 0, count( $dirs ) - 1 ); // pick a random subdir // In case all dirs are not filled, cycle through next digits... for ( $j = 0; $j < count( $dirs ); $j++ ) { $char = $dirs[( $place + $j ) % count( $dirs )]; $info = $this->pickImageDir( "$directory/$char", $levels - 1, $lockouts ); if ( $info ) { return $info; // found a captcha } else { wfDebug( "Could not find captcha in $directory.\n" ); $wgMemc->delete( $key ); // files changed on disk? } } return false; // didn't find any images in this directory... empty? } /** * @param $directory string * @param $lockouts integer * @return Array|bool */ protected function pickImageFromDir( $directory, &$lockouts ) { global $wgMemc; $backend = $this->getBackend(); $key = "fancycaptcha:filelist:{$backend->getWikiId()}:" . sha1( $directory ); $files = $wgMemc->get( $key ); // check cache if ( !is_array( $files ) || !count( $files ) ) { // cache miss $files = array(); // captcha files foreach ( $backend->getTopFileList( array( 'dir' => $directory ) ) as $entry ) { $files[] = $entry; if ( count( $files ) >= 500 ) { // sanity wfDebug( 'Skipping some captchas; $wgCaptchaDirectoryLevels set too low?.' ); break; } } if ( count( $files ) ) { $wgMemc->set( $key, $files, 86400 ); } wfDebug( "Cache miss for $directory captcha listing.\n" ); } if ( !count( $files ) ) { // Remove this directory if empty so callers don't keep looking here $backend->clean( array( 'dir' => $directory ) ); return false; } $info = $this->pickImageFromList( $directory, $files, $lockouts ); if ( !$info ) { wfDebug( "Could not find captcha in $directory.\n" ); $wgMemc->delete( $key ); // files changed on disk? } return $info; } /** * @param $directory string * @param $files array * @param $lockouts integer * @return boolean */ protected function pickImageFromList( $directory, array $files, &$lockouts ) { global $wgMemc, $wgCaptchaDeleteOnSolve; if ( !count( $files ) ) { return false; // none found } $backend = $this->getBackend(); $place = mt_rand( 0, count( $files ) - 1 ); // pick a random file $misses = 0; // number of files in listing that don't actually exist for ( $j = 0; $j < count( $files ); $j++ ) { $entry = $files[( $place + $j ) % count( $files )]; if ( preg_match( '/^image_([0-9a-f]+)_([0-9a-f]+)\\.png$/', $entry, $matches ) ) { if ( $wgCaptchaDeleteOnSolve ) { // captcha will be deleted when solved $key = "fancycaptcha:filelock:{$backend->getWikiId()}:" . sha1( $entry ); // Try to claim this captcha for 10 minutes (for the user to solve)... if ( ++$lockouts <= 10 && !$wgMemc->add( $key, '1', 600 ) ) { continue; // could not acquire (skip it to avoid race conditions) } } if ( !$backend->fileExists( array( 'src' => "$directory/$entry" ) ) ) { if ( ++$misses >= 5 ) { // too many files in the listing don't exist break; // listing cache too stale? break out so it will be cleared } continue; // try next file } return array( 'salt' => $matches[1], 'hash' => $matches[2], 'viewed' => false, ); } } return false; // none found } function showImage() { global $wgOut; $wgOut->disable(); $info = $this->retrieveCaptcha(); if ( $info ) { $timestamp = new MWTimestamp(); $info['viewed'] = $timestamp->getTimestamp(); $this->storeCaptcha( $info ); $salt = $info['salt']; $hash = $info['hash']; return $this->getBackend()->streamFile( array( 'src' => $this->imagePath( $salt, $hash ), 'headers' => array( "Cache-Control: private, s-maxage=0, max-age=3600" ) ) )->isOK(); } wfHttpError( 500, 'Internal Error', 'Requested bogus captcha image' ); return false; } /** * @param $salt string * @param $hash string * @return string */ public function imagePath( $salt, $hash ) { global $wgCaptchaDirectoryLevels; $file = $this->getBackend()->getRootStoragePath() . '/captcha-render/'; for ( $i = 0; $i < $wgCaptchaDirectoryLevels; $i++ ) { $file .= $hash{ $i } . '/'; } $file .= "image_{$salt}_{$hash}.png"; return $file; } /** * @param $basename string * @return Array (salt, hash) * @throws MWException */ public function hashFromImageName( $basename ) { if ( preg_match( '/^image_([0-9a-f]+)_([0-9a-f]+)\\.png$/', $basename, $matches ) ) { return array( $matches[1], $matches[2] ); } else { throw new MWException( "Invalid filename '$basename'.\n" ); } } /** * Show a message asking the user to enter a captcha on edit * The result will be treated as wiki text * * @param $action string Action being performed * @return string */ function getMessage( $action ) { $name = 'fancycaptcha-' . $action; $text = wfMessage( $name )->text(); # Obtain a more tailored message, if possible, otherwise, fall back to # the default for edits return wfMessage( $name, $text )->isDisabled() ? wfMessage( 'fancycaptcha-edit' )->text() : $text; } /** * Delete a solved captcha image, if $wgCaptchaDeleteOnSolve is true. */ function passCaptcha() { global $wgCaptchaDeleteOnSolve; $info = $this->retrieveCaptcha(); // get the captcha info before it gets deleted $pass = parent::passCaptcha(); if ( $pass && $wgCaptchaDeleteOnSolve ) { $this->getBackend()->quickDelete( array( 'src' => $this->imagePath( $info['salt'], $info['hash'] ) ) ); } return $pass; } }