diff options
Diffstat (limited to 'extensions/ConfirmEdit/FancyCaptcha/FancyCaptcha.class.php')
| -rw-r--r-- | extensions/ConfirmEdit/FancyCaptcha/FancyCaptcha.class.php | 416 |
1 files changed, 416 insertions, 0 deletions
diff --git a/extensions/ConfirmEdit/FancyCaptcha/FancyCaptcha.class.php b/extensions/ConfirmEdit/FancyCaptcha/FancyCaptcha.class.php new file mode 100644 index 00000000..0de148c2 --- /dev/null +++ b/extensions/ConfirmEdit/FancyCaptcha/FancyCaptcha.class.php @@ -0,0 +1,416 @@ +<?php + +class FancyCaptcha extends SimpleCaptcha { + /** + * @return FileBackend + */ + public function getBackend() { + global $wgCaptchaFileBackend, $wgCaptchaDirectory; + + if ( $wgCaptchaFileBackend ) { + return FileBackendGroup::singleton()->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, $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 = ''; + } + + $form = Html::openElement( 'div' ) . + Html::element( 'label', array( + 'for' => 'wpCaptchaWord', + ), + parent::getMessage( 'label' ) . ' ' . wfMessage( 'createacct-captcha' )->text() + ) . + Html::openElement( 'div', array( 'class' => 'mw-createacct-captcha-container' ) ) . + Html::openElement( 'div', array( 'class' => 'mw-createacct-captcha-and-reload' ) ) . + Html::openElement( 'div', array( 'class' => 'fancycaptcha-image-container' ) ) . + Html::element( 'img', array( + 'class' => 'fancycaptcha-image', + 'src' => $title->getLocalUrl( 'wpCaptchaId=' . urlencode( $index ) ), + 'alt' => '' + ) + ) . $captchaReload . Html::closeElement( 'div' ) . Html::closeElement( 'div' ) . "\n" . + Html::element( 'input', array( + 'name' => 'wpCaptchaWord', + 'class' => 'mw-ui-input', + 'id' => 'wpCaptchaWord', + 'type' => 'text', + 'size' => '12', // max_length in captcha.py plus fudge factor + 'autocomplete' => 'off', + 'autocorrect' => 'off', + 'autocapitalize' => 'off', + 'required' => 'required', + 'tabindex' => 1, + 'placeholder' => wfMessage( 'createacct-imgcaptcha-ph' ) + ) + ); // tab in before the edit textarea + if ( $this->action == 'usercreate' ) { + $form .= HTML::element( 'small',array( + 'class' => 'mw-createacct-captcha-assisted' + ), wfMessage( 'createacct-imgcaptcha-help' ) + ); + } + $form .= Html::element( 'input', array( + 'type' => 'hidden', + 'name' => 'wpCaptchaId', + 'id' => 'wpCaptchaId', + 'value' => $index + ) + ) . Html::closeElement( 'div' ) . Html::closeElement( 'div' ) . "\n"; + + return $form; + } + + /** + * Get captcha index key + * @return string captcha ID key + */ + function getCaptchaIndex() { + $info = $this->pickImage(); + if ( !$info ) { + throw new Exception( "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( 400, 'Request 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 Exception + */ + public function hashFromImageName( $basename ) { + if ( preg_match( '/^image_([0-9a-f]+)_([0-9a-f]+)\\.png$/', $basename, $matches ) ) { + return array( $matches[1], $matches[2] ); + } else { + throw new Exception( "Invalid filename '$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; + } +} |