getVal( 'wpCaptchaWord' ); $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; } } /** * Insert the captcha prompt into the edit form. */ function getForm() { $info = $this->pickImage(); if( !$info ) { die( "out of captcha images; this shouldn't happen" ); } // 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 ); wfDebug( "Captcha id $index using hash ${info['hash']}, salt ${info['salt']}.\n" ); $title = Title::makeTitle( NS_SPECIAL, 'Captcha/image' ); return "
" . wfElement( 'img', array( 'src' => $title->getLocalUrl( 'wpCaptchaId=' . urlencode( $index ) ), 'width' => $info['width'], 'height' => $info['height'], 'alt' => '' ) ) . "
\n" . wfElement( 'input', array( 'type' => 'hidden', 'name' => 'wpCaptchaId', 'id' => 'wpCaptchaId', 'value' => $index ) ) . "" . wfElement( 'input', array( 'name' => 'wpCaptchaWord', 'id' => 'wpCaptchaWord', 'tabindex' => 1 ) ) . // tab in before the edit textarea "
\n"; } /** * Select a previously generated captcha image from the queue. * @fixme subject to race conditions if lots of files vanish * @return mixed tuple of (salt key, text hash) or false if no image to find */ function pickImage() { global $wgCaptchaDirectory, $wgCaptchaDirectoryLevels; return $this->pickImageDir( $wgCaptchaDirectory, $wgCaptchaDirectoryLevels ); } function pickImageDir( $directory, $levels ) { if( $levels ) { $dirs = array(); // Check which subdirs are actually present... $dir = opendir( $directory ); while( false !== ($entry = readdir( $dir ) ) ) { if( ctype_xdigit( $entry ) && strlen( $entry ) == 1 ) { $dirs[] = $entry; } } closedir( $dir ); $place = mt_rand( 0, count( $dirs ) - 1 ); // In case all dirs are not filled, // cycle through next digits... for( $j = 0; $j < count( $dirs ); $j++ ) { $char = $dirs[($place + $j) % count( $dirs )]; $return = $this->pickImageDir( "$directory/$char", $levels - 1 ); if( $return ) { return $return; } } // Didn't find any images in this directory... empty? return false; } else { return $this->pickImageFromDir( $directory ); } } function pickImageFromDir( $directory ) { if( !is_dir( $directory ) ) { return false; } $n = mt_rand( 0, $this->countFiles( $directory ) - 1 ); $dir = opendir( $directory ); $count = 0; $entry = readdir( $dir ); $pick = false; while( false !== $entry ) { $entry = readdir( $dir ); if( preg_match( '/^image_([0-9a-f]+)_([0-9a-f]+)\\.png$/', $entry, $matches ) ) { $size = getimagesize( "$directory/$entry" ); $pick = array( 'salt' => $matches[1], 'hash' => $matches[2], 'width' => $size[0], 'height' => $size[1], 'viewed' => false, ); if( $count++ == $n ) { break; } } } closedir( $dir ); return $pick; } /** * Count the number of files in a directory. * @return int */ function countFiles( $dirname ) { $dir = opendir( $dirname ); $count = 0; while( false !== ($entry = readdir( $dir ) ) ) { if( $entry != '.' && $entry != '..' ) { $count++; } } closedir( $dir ); return $count; } function showImage() { global $wgOut, $wgRequest; $wgOut->disable(); $info = $this->retrieveCaptcha(); if( $info ) { if( $info['viewed'] ) { wfHttpError( 403, 'Access Forbidden', "Can't view captcha image a second time." ); return false; } $info['viewed'] = wfTimestamp(); $this->storeCaptcha( $info ); $salt = $info['salt']; $hash = $info['hash']; $file = $this->imagePath( $salt, $hash ); if( file_exists( $file ) ) { global $IP; require_once "$IP/includes/StreamFile.php"; wfStreamFile( $file ); return true; } } wfHttpError( 500, 'Internal Error', 'Requested bogus captcha image' ); return false; } function imagePath( $salt, $hash ) { global $wgCaptchaDirectory, $wgCaptchaDirectoryLevels; $file = $wgCaptchaDirectory; $file .= DIRECTORY_SEPARATOR; for( $i = 0; $i < $wgCaptchaDirectoryLevels; $i++ ) { $file .= $hash{$i}; $file .= DIRECTORY_SEPARATOR; } $file .= "image_{$salt}_{$hash}.png"; return $file; } /** * Show a message asking the user to enter a captcha on edit * The result will be treated as wiki text * * @param $action Action being performed * @return string */ function getMessage( $action ) { $name = 'fancycaptcha-' . $action; $text = wfMsg( $name ); # Obtain a more tailored message, if possible, otherwise, fall back to # the default for edits return wfEmptyMsg( $name, $text ) ? wfMsg( 'fancycaptcha-edit' ) : $text; } }