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<?php
class FancyCaptcha extends SimpleCaptcha {
/**
* 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>" .
Xml::element( 'img', array(
'src' => $title->getLocalUrl( 'wpCaptchaId=' . urlencode( $index ) ),
'width' => $info['width'],
'height' => $info['height'],
'alt' => '' ) ) .
"</p>\n" .
Xml::element( 'input', array(
'type' => 'hidden',
'name' => 'wpCaptchaId',
'id' => 'wpCaptchaId',
'value' => $index ) ) .
"<p>" .
Html::element( 'input', array(
'name' => 'wpCaptchaWord',
'id' => 'wpCaptchaWord',
'autocorrect' => 'off',
'autocapitalize' => 'off',
'required',
'tabindex' => 1 ) ) . // tab in before the edit textarea
"</p>\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;
$wgOut->disable();
$info = $this->retrieveCaptcha();
if ( $info ) {
/*
// Be a little less restrictive for now; in at least some circumstances,
// Konqueror tries to reload the image even if you haven't navigated
// away from the page.
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";
header( "Cache-Control: private, s-maxage=0, max-age=3600" );
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;
}
/**
* 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 ) {
$filename = $this->imagePath( $info['salt'], $info['hash'] );
if ( file_exists( $filename ) ) {
unlink( $filename );
}
}
return $pass;
}
}
|
