mediawiki-extensions-Confir.../FancyCaptcha/includes/FancyCaptcha.php

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<?php
namespace MediaWiki\Extension\ConfirmEdit\FancyCaptcha;
use FileBackend;
use FSFileBackend;
use InvalidArgumentException;
use MediaWiki\Auth\AuthenticationRequest;
use MediaWiki\Auth\AuthManager;
use MediaWiki\Context\RequestContext;
use MediaWiki\Extension\ConfirmEdit\Auth\CaptchaAuthenticationRequest;
use MediaWiki\Extension\ConfirmEdit\SimpleCaptcha\SimpleCaptcha;
use MediaWiki\Html\Html;
use MediaWiki\MediaWikiServices;
use MediaWiki\SpecialPage\SpecialPage;
use MediaWiki\Utils\MWTimestamp;
use MediaWiki\WikiMap\WikiMap;
use NullLockManager;
use StatusValue;
use UnderflowException;
/**
* FancyCaptcha for displaying captchas precomputed by captcha.py
*/
class FancyCaptcha extends SimpleCaptcha {
// used for fancycaptcha-edit, fancycaptcha-addurl, fancycaptcha-badlogin,
// fancycaptcha-accountcreate, fancycaptcha-create, fancycaptcha-sendemail via getMessage()
protected static $messagePrefix = 'fancycaptcha-';
/**
* @return FileBackend
*/
public function getBackend() {
global $wgCaptchaFileBackend, $wgCaptchaDirectory;
if ( $wgCaptchaFileBackend ) {
return MediaWikiServices::getInstance()->getFileBackendGroup()
->get( $wgCaptchaFileBackend );
}
static $backend = null;
if ( !$backend ) {
$backend = new FSFileBackend( [
'name' => 'captcha-backend',
'wikiId' => WikiMap::getCurrentWikiId(),
'lockManager' => new NullLockManager( [] ),
'containerPaths' => [ $this->getStorageDir() => $wgCaptchaDirectory ],
'fileMode' => 777,
'obResetFunc' => 'wfResetOutputBuffers',
'streamMimeFunc' => [ 'StreamFile', 'contentTypeFromPath' ]
] );
}
return $backend;
}
/**
* @return int Number of captcha files
*/
public function getCaptchaCount() {
$backend = $this->getBackend();
$files = $backend->getFileList(
[ 'dir' => $backend->getRootStoragePath() . '/' . $this->getStorageDir() ]
);
return iterator_count( $files );
}
/**
* @return string
*/
public function getStorageDir() {
global $wgCaptchaStorageDirectory;
return $wgCaptchaStorageDirectory;
}
/**
* 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
*/
protected 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;
}
}
/**
* @param array &$resultArr
*/
protected function addCaptchaAPI( &$resultArr ) {
$info = $this->pickImage();
if ( !$info ) {
$resultArr['captcha']['error'] = 'Out of images';
return;
}
$index = $this->storeCaptcha( $info );
$title = SpecialPage::getTitleFor( 'Captcha', 'image' );
$resultArr['captcha'] = $this->describeCaptchaType();
$resultArr['captcha']['id'] = $index;
$resultArr['captcha']['url'] = $title->getLocalURL( 'wpCaptchaId=' . urlencode( $index ) );
}
/**
* @return array
*/
public function describeCaptchaType() {
return [
'type' => 'image',
'mime' => 'image/png',
];
}
/**
* @param int $tabIndex
* @return array
*/
public function getFormInformation( $tabIndex = 1 ) {
$title = SpecialPage::getTitleFor( 'Captcha', 'image' );
$info = $this->getCaptcha();
$index = $this->storeCaptcha( $info );
$captchaReload = Html::element(
'small',
[
'class' => 'confirmedit-captcha-reload fancycaptcha-reload'
],
wfMessage( 'fancycaptcha-reload-text' )->text()
);
$form = Html::openElement( 'div' ) .
Html::element( 'label', [
'for' => 'wpCaptchaWord',
],
wfMessage( 'captcha-label' )->text() . ' ' . wfMessage( 'fancycaptcha-captcha' )->text()
) .
Html::openElement( 'div', [ 'class' => 'fancycaptcha-captcha-container' ] ) .
Html::openElement( 'div', [ 'class' => 'fancycaptcha-captcha-and-reload' ] ) .
Html::openElement( 'div', [ 'class' => 'fancycaptcha-image-container' ] ) .
Html::element( 'img', [
'class' => 'fancycaptcha-image',
'src' => $title->getLocalURL( 'wpCaptchaId=' . urlencode( $index ) ),
'alt' => ''
]
) . $captchaReload . Html::closeElement( 'div' ) . Html::closeElement( 'div' ) . "\n" .
// FIXME: This should use CodexHTMLForm rather than Html::element
Html::openElement( 'div', [ 'class' => 'cdx-text-input' ] ) .
Html::element( 'input', [
'name' => 'wpCaptchaWord',
'class' => 'cdx-text-input__input',
'id' => 'wpCaptchaWord',
'type' => 'text',
// max_length in captcha.py plus fudge factor
'size' => '12',
'autocomplete' => 'off',
'autocorrect' => 'off',
'autocapitalize' => 'off',
'required' => 'required',
// tab in before the edit textarea
'tabindex' => $tabIndex,
'placeholder' => wfMessage( 'fancycaptcha-imgcaptcha-ph' )->text()
]
) . Html::closeElement( 'div' );
if ( $this->action == 'createaccount' ) {
// use raw element, because the message can contain links or some other html
$form .= Html::rawElement( 'small', [
'class' => 'mw-createacct-captcha-assisted'
], wfMessage( 'createacct-imgcaptcha-help' )->parse()
);
}
$form .= Html::element( 'input', [
'type' => 'hidden',
'name' => 'wpCaptchaId',
'id' => 'wpCaptchaId',
'value' => $index
]
) . Html::closeElement( 'div' ) . Html::closeElement( 'div' ) . "\n";
return [
'html' => $form,
'modules' => [ 'ext.confirmEdit.fancyCaptcha' ],
// Uses addModuleStyles so it is loaded when JS is disabled.
'modulestyles' => [ 'codex-styles', 'ext.confirmEdit.fancyCaptcha.styles' ],
];
}
/**
* 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;
// number of times another process claimed a file before this one
$lockouts = 0;
$baseDir = $this->getBackend()->getRootStoragePath() . '/' . $this->getStorageDir();
return $this->pickImageDir( $baseDir, $wgCaptchaDirectoryLevels, $lockouts );
}
/**
* @param string $directory
* @param int $levels
* @param int &$lockouts
* @return array|bool
*/
protected function pickImageDir( $directory, $levels, &$lockouts ) {
if ( $levels <= 0 ) {
// $directory has regular files
return $this->pickImageFromDir( $directory, $lockouts );
}
$backend = $this->getBackend();
$cache = MediaWikiServices::getInstance()->getObjectCacheFactory()->getLocalClusterInstance();
$key = $cache->makeGlobalKey(
'fancycaptcha-dirlist',
$backend->getDomainId(),
sha1( $directory )
);
// check cache
$dirs = $cache->get( $key );
if ( !is_array( $dirs ) || !count( $dirs ) ) {
// cache miss
$dirs = [];
// subdirs actually present...
foreach ( $backend->getTopDirectoryList( [ 'dir' => $directory ] ) as $entry ) {
if ( ctype_xdigit( $entry ) && strlen( $entry ) == 1 ) {
$dirs[] = $entry;
}
}
wfDebug( "Cache miss for $directory subdirectory listing.\n" );
if ( count( $dirs ) ) {
$cache->set( $key, $dirs, 86400 );
}
}
if ( !count( $dirs ) ) {
// Remove this directory if empty so callers don't keep looking here
$backend->clean( [ 'dir' => $directory ] );
// none found
return false;
}
// pick a random subdir
$place = mt_rand( 0, count( $dirs ) - 1 );
// In case all dirs are not filled, cycle through next digits...
$fancyCount = count( $dirs );
for ( $j = 0; $j < $fancyCount; $j++ ) {
$char = $dirs[( $place + $j ) % count( $dirs )];
$info = $this->pickImageDir( "$directory/$char", $levels - 1, $lockouts );
if ( $info ) {
// found a captcha
return $info;
} else {
wfDebug( "Could not find captcha in $directory.\n" );
// files changed on disk?
$cache->delete( $key );
}
}
// didn't find any images in this directory... empty?
return false;
}
/**
* @param string $directory
* @param int &$lockouts
* @return array|bool
*/
protected function pickImageFromDir( $directory, &$lockouts ) {
$backend = $this->getBackend();
$cache = MediaWikiServices::getInstance()->getObjectCacheFactory()->getLocalClusterInstance();
$key = $cache->makeGlobalKey(
'fancycaptcha-filelist',
$backend->getDomainId(),
sha1( $directory )
);
// check cache
$files = $cache->get( $key );
if ( !is_array( $files ) || !count( $files ) ) {
// cache miss
$files = [];
foreach ( $backend->getTopFileList( [ 'dir' => $directory ] ) as $entry ) {
$files[] = $entry;
if ( count( $files ) >= 500 ) {
// sanity
wfDebug( 'Skipping some captchas; $wgCaptchaDirectoryLevels set too low?.' );
break;
}
}
if ( count( $files ) ) {
$cache->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( [ 'dir' => $directory ] );
return false;
}
$info = $this->pickImageFromList( $directory, $files, $lockouts );
if ( !$info ) {
wfDebug( "Could not find captcha in $directory.\n" );
// files changed on disk?
$cache->delete( $key );
}
return $info;
}
/**
* @param string $directory
* @param array $files
* @param int &$lockouts
* @return array|bool
*/
protected function pickImageFromList( $directory, array $files, &$lockouts ) {
global $wgCaptchaDeleteOnSolve;
if ( !count( $files ) ) {
// none found
return false;
}
$backend = $this->getBackend();
$cache = MediaWikiServices::getInstance()->getObjectCacheFactory()->getLocalClusterInstance();
// pick a random file
$place = mt_rand( 0, count( $files ) - 1 );
// number of files in listing that don't actually exist
$misses = 0;
$fancyImageCount = count( $files );
for ( $j = 0; $j < $fancyImageCount; $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 = $cache->makeGlobalKey(
'fancycaptcha-filelock',
$backend->getDomainId(),
sha1( $entry )
);
// Try to claim this captcha for 10 minutes (for the user to solve)...
if ( ++$lockouts <= 10 && !$cache->add( $key, '1', 600 ) ) {
// could not acquire (skip it to avoid race conditions)
continue;
}
}
if ( !$backend->fileExists( [ 'src' => "$directory/$entry" ] ) ) {
if ( ++$misses >= 5 ) {
// too many files in the listing don't exist
// listing cache too stale? break out so it will be cleared
break;
}
// try next file
continue;
}
return [
'salt' => $matches[1],
'hash' => $matches[2],
'viewed' => false,
];
}
}
// none found
return false;
}
/**
* @return bool|StatusValue
*/
public function showImage() {
$context = RequestContext::getMain();
$context->getOutput()->disable();
$index = $context->getRequest()->getVal( 'wpCaptchaId' );
$info = $this->retrieveCaptcha( $index );
if ( $info ) {
$timestamp = new MWTimestamp();
$info['viewed'] = $timestamp->getTimestamp();
$this->storeCaptcha( $info );
$salt = $info['salt'];
$hash = $info['hash'];
return $this->getBackend()->streamFile( [
'src' => $this->imagePath( $salt, $hash ),
'headers' => [ "Cache-Control: private, s-maxage=0, max-age=3600" ]
] )->isOK();
}
wfHttpError( 400, 'Request Error', 'Requested bogus captcha image' );
return false;
}
/**
* @param string $salt
* @param string $hash
* @return string
*/
public function imagePath( $salt, $hash ) {
global $wgCaptchaDirectoryLevels;
$file = $this->getBackend()->getRootStoragePath() . '/' . $this->getStorageDir() . '/';
for ( $i = 0; $i < $wgCaptchaDirectoryLevels; $i++ ) {
$file .= $hash[ $i ] . '/';
}
$file .= "image_{$salt}_{$hash}.png";
return $file;
}
/**
* @param string $basename
* @return array (salt, hash)
*/
public function hashFromImageName( $basename ) {
if ( preg_match( '/^image_([0-9a-f]+)_([0-9a-f]+)\\.png$/', $basename, $matches ) ) {
return [ $matches[1], $matches[2] ];
} else {
throw new InvalidArgumentException( "Invalid filename '$basename'.\n" );
}
}
/**
* Delete a solved captcha image, if $wgCaptchaDeleteOnSolve is true.
* @inheritDoc
*/
protected function passCaptcha( $index, $word ) {
global $wgCaptchaDeleteOnSolve;
// get the captcha info before it gets deleted
$info = $this->retrieveCaptcha( $index );
$pass = parent::passCaptcha( $index, $word );
if ( $pass && $wgCaptchaDeleteOnSolve ) {
$this->getBackend()->quickDelete( [
'src' => $this->imagePath( $info['salt'], $info['hash'] )
] );
}
return $pass;
}
/**
* Returns an array with 'salt' and 'hash' keys. Hash is
* md5( $wgCaptchaSecret . $salt . $answer . $wgCaptchaSecret . $salt )[0..15]
* @return array
* @throws UnderflowException When a captcha image cannot be produced.
*/
public function getCaptcha() {
$info = $this->pickImage();
if ( !$info ) {
throw new UnderflowException( 'Ran out of captcha images' );
}
return $info;
}
/**
* @param array $captchaData
* @param string $id
* @return string
*/
public function getCaptchaInfo( $captchaData, $id ) {
$title = SpecialPage::getTitleFor( 'Captcha', 'image' );
return $title->getLocalURL( 'wpCaptchaId=' . urlencode( $id ) );
}
/**
* @param array $requests
* @param array $fieldInfo
* @param array &$formDescriptor
* @param string $action
*/
public function onAuthChangeFormFields(
array $requests, array $fieldInfo, array &$formDescriptor, $action
) {
/** @var CaptchaAuthenticationRequest $req */
$req =
AuthenticationRequest::getRequestByClass( $requests,
CaptchaAuthenticationRequest::class, true );
if ( !$req ) {
return;
}
// HTMLFancyCaptchaField will include this
unset( $formDescriptor['captchaInfo' ] );
$formDescriptor['captchaWord'] = [
'class' => HTMLFancyCaptchaField::class,
'imageUrl' => $this->getCaptchaInfo( $req->captchaData, $req->captchaId ),
'label-message' => $this->getMessage( $this->action ),
'showCreateHelp' => in_array( $action, [
AuthManager::ACTION_CREATE,
AuthManager::ACTION_CREATE_CONTINUE
], true ),
] + $formDescriptor['captchaWord'];
}
}
class_alias( FancyCaptcha::class, 'FancyCaptcha' );