mediawiki-extensions-Confir.../FancyCaptcha.class.php
Aaron Schulz 93e45f2870 Removed redundant width/height tags to avoid getimagesize() call.
Change-Id: I8dc1a343d107536ba038fe9f20c5a1819d3c1b11
2013-01-07 01:43:00 +00:00

368 lines
11 KiB
PHP

<?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',
'lockManager' => 'nullLockManager',
'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() {
$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 );
wfDebug( "Captcha id $index using hash ${info['hash']}, salt ${info['salt']}.\n" );
$title = SpecialPage::getTitleFor( 'Captcha', 'image' );
return "<p>" .
Html::element( 'img', array(
'src' => $title->getLocalUrl( 'wpCaptchaId=' . urlencode( $index ) ),
'alt' => '' ) ) .
"</p>\n" .
Html::element( 'input', array(
'type' => 'hidden',
'name' => 'wpCaptchaId',
'id' => 'wpCaptchaId',
'value' => $index ) ) .
'<p>' .
Html::element( 'label', array(
'for' => 'wpCaptchaWord',
), parent::getMessage( 'label' ) . wfMessage( 'colon-separator' )->text() ) .
Html::element( 'input', array(
'name' => 'wpCaptchaWord',
'id' => 'wpCaptchaWord',
'type' => 'text',
'autocorrect' => 'off',
'autocapitalize' => 'off',
'required' => 'required',
'tabindex' => 1 ) ) . // tab in before the edit textarea
"</p>\n";
}
/**
* 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;
}
}