mediawiki-extensions-Confir.../Captcha.php
Brion Vibber 19dcbb6fa2 Update ConfirmEdit to return Status object on AbortNewAccount hook
Requires core update I6ae34c0 to actually send the message key back
in the error response. On older MediaWiki versions, behavior should
remain unchanged.

Bug: 60008
Change-Id: If9cc08e44d1d2efacf817b8c6cbb2d71a4e8b692
2014-01-17 13:38:51 -08:00

837 lines
23 KiB
PHP
Raw Blame History

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<?php
class SimpleCaptcha {
function getCaptcha() {
$a = mt_rand( 0, 100 );
$b = mt_rand( 0, 10 );
/* Minus sign is used in the question. UTF-8,
since the api uses text/plain, not text/html */
$op = mt_rand( 0, 1 ) ? '+' : '';
// No space before and after $op, to ensure correct
// directionality.
$test = "$a$op$b";
$answer = ( $op == '+' ) ? ( $a + $b ) : ( $a - $b );
return array( 'question' => $test, 'answer' => $answer );
}
function addCaptchaAPI( &$resultArr ) {
$captcha = $this->getCaptcha();
$index = $this->storeCaptcha( $captcha );
$resultArr['captcha']['type'] = 'simple';
$resultArr['captcha']['mime'] = 'text/plain';
$resultArr['captcha']['id'] = $index;
$resultArr['captcha']['question'] = $captcha['question'];
}
/**
* Insert a captcha prompt into the edit form.
* This sample implementation generates a simple arithmetic operation;
* it would be easy to defeat by machine.
*
* Override this!
*
* @return string HTML
*/
function getForm() {
$captcha = $this->getCaptcha();
$index = $this->storeCaptcha( $captcha );
return "<p><label for=\"wpCaptchaWord\">{$captcha['question']}</label> = " .
Xml::element( 'input', array(
'name' => 'wpCaptchaWord',
'id' => 'wpCaptchaWord',
'size' => 5,
'autocomplete' => 'off',
'tabindex' => 1 ) ) . // tab in before the edit textarea
"</p>\n" .
Xml::element( 'input', array(
'type' => 'hidden',
'name' => 'wpCaptchaId',
'id' => 'wpCaptchaId',
'value' => $index ) );
}
/**
* Insert the captcha prompt into an edit form.
* @param OutputPage $out
*/
function editCallback( &$out ) {
$out->addWikiText( $this->getMessage( $this->action ) );
$out->addHTML( $this->getForm() );
}
/**
* 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 = 'captcha-' . $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( 'captcha-edit' )->text() : $text;
}
/**
* Inject whazawhoo
* @fixme if multiple thingies insert a header, could break
* @param $form HTMLForm
* @return bool true to keep running callbacks
*/
function injectEmailUser( &$form ) {
global $wgCaptchaTriggers, $wgOut, $wgUser;
if ( $wgCaptchaTriggers['sendemail'] ) {
if ( $wgUser->isAllowed( 'skipcaptcha' ) ) {
wfDebug( "ConfirmEdit: user group allows skipping captcha on email sending\n" );
return true;
}
$form->addFooterText(
"<div class='captcha'>" .
$wgOut->parse( $this->getMessage( 'sendemail' ) ) .
$this->getForm() .
"</div>\n" );
}
return true;
}
/**
* Inject whazawhoo
* @fixme if multiple thingies insert a header, could break
* @param QuickTemplate $template
* @return bool true to keep running callbacks
*/
function injectUserCreate( &$template ) {
global $wgCaptchaTriggers, $wgOut, $wgUser;
if ( $wgCaptchaTriggers['createaccount'] ) {
if ( $wgUser->isAllowed( 'skipcaptcha' ) ) {
wfDebug( "ConfirmEdit: user group allows skipping captcha on account creation\n" );
return true;
}
$template->set( 'header',
"<div class='captcha'>" .
$wgOut->parse( $this->getMessage( 'createaccount' ) ) .
$this->getForm() .
"</div>\n" );
}
return true;
}
/**
* Inject a captcha into the user login form after a failed
* password attempt as a speedbump for mass attacks.
* @fixme if multiple thingies insert a header, could break
* @param $template QuickTemplate
* @return bool true to keep running callbacks
*/
function injectUserLogin( &$template ) {
if ( $this->isBadLoginTriggered() ) {
global $wgOut;
$template->set( 'header',
"<div class='captcha'>" .
$wgOut->parse( $this->getMessage( 'badlogin' ) ) .
$this->getForm() .
"</div>\n" );
}
return true;
}
/**
* When a bad login attempt is made, increment an expiring counter
* in the memcache cloud. Later checks for this may trigger a
* captcha display to prevent too many hits from the same place.
* @param User $user
* @param string $password
* @param int $retval authentication return value
* @return bool true to keep running callbacks
*/
function triggerUserLogin( $user, $password, $retval ) {
global $wgCaptchaTriggers, $wgCaptchaBadLoginExpiration, $wgMemc;
if ( $retval == LoginForm::WRONG_PASS && $wgCaptchaTriggers['badlogin'] ) {
$key = $this->badLoginKey();
$count = $wgMemc->get( $key );
if ( !$count ) {
$wgMemc->add( $key, 0, $wgCaptchaBadLoginExpiration );
}
$wgMemc->incr( $key );
}
return true;
}
/**
* Check if a bad login has already been registered for this
* IP address. If so, require a captcha.
* @return bool
* @access private
*/
function isBadLoginTriggered() {
global $wgMemc, $wgCaptchaTriggers, $wgCaptchaBadLoginAttempts;
return $wgCaptchaTriggers['badlogin'] && intval( $wgMemc->get( $this->badLoginKey() ) ) >= $wgCaptchaBadLoginAttempts;
}
/**
* Check if the IP is allowed to skip captchas
*/
function isIPWhitelisted() {
global $wgCaptchaWhitelistIP;
if ( $wgCaptchaWhitelistIP ) {
global $wgRequest;
$ip = $wgRequest->getIP();
foreach ( $wgCaptchaWhitelistIP as $range ) {
if ( IP::isInRange( $ip, $range ) ) {
return true;
}
}
}
return false;
}
/**
* Internal cache key for badlogin checks.
* @return string
* @access private
*/
function badLoginKey() {
global $wgRequest;
$ip = $wgRequest->getIP();
return wfMemcKey( 'captcha', 'badlogin', 'ip', $ip );
}
/**
* Check if the submitted form matches the captcha session data provided
* by the plugin when the form was generated.
*
* Override this!
*
* @param string $answer
* @param array $info
* @return bool
*/
function keyMatch( $answer, $info ) {
return $answer == $info['answer'];
}
// ----------------------------------
/**
* @param EditPage $editPage
* @param string $action (edit/create/addurl...)
* @return bool true if action triggers captcha on editPage's namespace
*/
function captchaTriggers( &$editPage, $action ) {
global $wgCaptchaTriggers, $wgCaptchaTriggersOnNamespace;
// Special config for this NS?
if ( isset( $wgCaptchaTriggersOnNamespace[$editPage->mTitle->getNamespace()][$action] ) )
return $wgCaptchaTriggersOnNamespace[$editPage->mTitle->getNamespace()][$action];
return ( !empty( $wgCaptchaTriggers[$action] ) ); // Default
}
/**
* @param $editPage EditPage
* @param $newtext string
* @param $section string
* @param $merged bool
* @return bool true if the captcha should run
*/
function shouldCheck( &$editPage, $newtext, $section, $merged = false ) {
$this->trigger = '';
$title = $editPage->mArticle->getTitle();
global $wgUser;
if ( $wgUser->isAllowed( 'skipcaptcha' ) ) {
wfDebug( "ConfirmEdit: user group allows skipping captcha\n" );
return false;
}
if ( $this->isIPWhitelisted() )
return false;
global $wgEmailAuthentication, $ceAllowConfirmedEmail;
if ( $wgEmailAuthentication && $ceAllowConfirmedEmail &&
$wgUser->isEmailConfirmed() ) {
wfDebug( "ConfirmEdit: user has confirmed mail, skipping captcha\n" );
return false;
}
if ( $this->captchaTriggers( $editPage, 'edit' ) ) {
// Check on all edits
global $wgUser;
$this->trigger = sprintf( "edit trigger by '%s' at [[%s]]",
$wgUser->getName(),
$title->getPrefixedText() );
$this->action = 'edit';
wfDebug( "ConfirmEdit: checking all edits...\n" );
return true;
}
if ( $this->captchaTriggers( $editPage, 'create' ) && !$editPage->mTitle->exists() ) {
// Check if creating a page
global $wgUser;
$this->trigger = sprintf( "Create trigger by '%s' at [[%s]]",
$wgUser->getName(),
$title->getPrefixedText() );
$this->action = 'create';
wfDebug( "ConfirmEdit: checking on page creation...\n" );
return true;
}
if ( $this->captchaTriggers( $editPage, 'addurl' ) ) {
// Only check edits that add URLs
if ( $merged ) {
// Get links from the database
$oldLinks = $this->getLinksFromTracker( $title );
// Share a parse operation with Article::doEdit()
$editInfo = $editPage->mArticle->prepareTextForEdit( $newtext );
$newLinks = array_keys( $editInfo->output->getExternalLinks() );
} else {
// Get link changes in the slowest way known to man
$oldtext = $this->loadText( $editPage, $section );
$oldLinks = $this->findLinks( $editPage, $oldtext );
$newLinks = $this->findLinks( $editPage, $newtext );
}
$unknownLinks = array_filter( $newLinks, array( &$this, 'filterLink' ) );
$addedLinks = array_diff( $unknownLinks, $oldLinks );
$numLinks = count( $addedLinks );
if ( $numLinks > 0 ) {
global $wgUser;
$this->trigger = sprintf( "%dx url trigger by '%s' at [[%s]]: %s",
$numLinks,
$wgUser->getName(),
$title->getPrefixedText(),
implode( ", ", $addedLinks ) );
$this->action = 'addurl';
return true;
}
}
global $wgCaptchaRegexes;
if ( $wgCaptchaRegexes ) {
// Custom regex checks. Reuse $oldtext if set above.
$oldtext = isset( $oldtext ) ? $oldtext : $this->loadText( $editPage, $section );
foreach ( $wgCaptchaRegexes as $regex ) {
$newMatches = array();
if ( preg_match_all( $regex, $newtext, $newMatches ) ) {
$oldMatches = array();
preg_match_all( $regex, $oldtext, $oldMatches );
$addedMatches = array_diff( $newMatches[0], $oldMatches[0] );
$numHits = count( $addedMatches );
if ( $numHits > 0 ) {
global $wgUser;
$this->trigger = sprintf( "%dx %s at [[%s]]: %s",
$numHits,
$regex,
$wgUser->getName(),
$title->getPrefixedText(),
implode( ", ", $addedMatches ) );
$this->action = 'edit';
return true;
}
}
}
}
return false;
}
/**
* Filter callback function for URL whitelisting
* @param $url string to check
* @return bool true if unknown, false if whitelisted
* @access private
*/
function filterLink( $url ) {
global $wgCaptchaWhitelist;
static $regexes = null;
if ( $regexes === null ) {
$source = wfMessage( 'captcha-addurl-whitelist' )->inContentLanguage();
$regexes = $source->isDisabled()
? array()
: $this->buildRegexes( explode( "\n", $source->plain() ) );
if ( $wgCaptchaWhitelist !== false ) {
array_unshift( $regexes, $wgCaptchaWhitelist );
}
}
foreach ( $regexes as $regex ) {
if ( preg_match( $regex, $url ) ) {
return false;
}
}
return true;
}
/**
* Build regex from whitelist
* @param $lines string from [[MediaWiki:Captcha-addurl-whitelist]]
* @return array Regexes
* @access private
*/
function buildRegexes( $lines ) {
# Code duplicated from the SpamBlacklist extension (r19197)
# and later modified.
# Strip comments and whitespace, then remove blanks
$lines = array_filter( array_map( 'trim', preg_replace( '/#.*$/', '', $lines ) ) );
# No lines, don't make a regex which will match everything
if ( count( $lines ) == 0 ) {
wfDebug( "No lines\n" );
return array();
} else {
# Make regex
# It's faster using the S modifier even though it will usually only be run once
// $regex = 'http://+[a-z0-9_\-.]*(' . implode( '|', $lines ) . ')';
// return '/' . str_replace( '/', '\/', preg_replace('|\\\*/|', '/', $regex) ) . '/Si';
$regexes = array();
$regexStart = array(
'normal' => '/^https?:\/\/+[a-z0-9_\-.]*(?:',
'noprotocol' => '/^(?:',
);
$regexEnd = array(
'normal' => ')/Si',
'noprotocol' => ')/Si',
);
$regexMax = 4096;
$build = array();
foreach ( $lines as $line ) {
# Extract flags from the line
$options = array();
if ( preg_match( '/^(.*?)\s*<([^<>]*)>$/', $line, $matches ) ) {
if ( $matches[1] === '' ) {
wfDebug( "Line with empty regex\n" );
continue;
}
$line = $matches[1];
$opts = preg_split( '/\s*\|\s*/', trim( $matches[2] ) );
foreach ( $opts as $opt ) {
$opt = strtolower( $opt );
if ( $opt == 'noprotocol' ) {
$options['noprotocol'] = true;
}
}
}
$key = isset( $options['noprotocol'] ) ? 'noprotocol' : 'normal';
// FIXME: not very robust size check, but should work. :)
if ( !isset( $build[$key] ) ) {
$build[$key] = $line;
} elseif ( strlen( $build[$key] ) + strlen( $line ) > $regexMax ) {
$regexes[] = $regexStart[$key] .
str_replace( '/', '\/', preg_replace( '|\\\*/|', '/', $build[$key] ) ) .
$regexEnd[$key];
$build[$key] = $line;
} else {
$build[$key] .= '|' . $line;
}
}
foreach ( $build as $key => $value ) {
$regexes[] = $regexStart[$key] .
str_replace( '/', '\/', preg_replace( '|\\\*/|', '/', $build[$key] ) ) .
$regexEnd[$key];
}
return $regexes;
}
}
/**
* Load external links from the externallinks table
* @param $title Title
* @return Array
*/
function getLinksFromTracker( $title ) {
$dbr = wfGetDB( DB_SLAVE );
$id = $title->getArticleID(); // should be zero queries
$res = $dbr->select( 'externallinks', array( 'el_to' ),
array( 'el_from' => $id ), __METHOD__ );
$links = array();
foreach ( $res as $row ) {
$links[] = $row->el_to;
}
return $links;
}
/**
* Backend function for confirmEdit() and confirmEditAPI()
* @param $editPage EditPage
* @param $newtext string
* @param $section
* @param $merged bool
* @return bool false if the CAPTCHA is rejected, true otherwise
*/
private function doConfirmEdit( $editPage, $newtext, $section, $merged = false ) {
global $wgRequest;
if ( $wgRequest->getVal( 'captchaid' ) ) {
$wgRequest->setVal( 'wpCaptchaId', $wgRequest->getVal( 'captchaid' ) );
}
if ( $wgRequest->getVal( 'captchaword' ) ) {
$wgRequest->setVal( 'wpCaptchaWord', $wgRequest->getVal( 'captchaword' ) );
}
if ( $this->shouldCheck( $editPage, $newtext, $section, $merged ) ) {
return $this->passCaptcha();
} else {
wfDebug( "ConfirmEdit: no need to show captcha.\n" );
return true;
}
}
/**
* The main callback run on edit attempts.
* @param EditPage $editPage
* @param string $newtext
* @param string $section
* @param bool $merged
* @return bool true to continue saving, false to abort and show a captcha form
*/
function confirmEdit( $editPage, $newtext, $section, $merged = false ) {
if ( defined( 'MW_API' ) ) {
# API mode
# The CAPTCHA was already checked and approved
return true;
}
if ( !$this->doConfirmEdit( $editPage, $newtext, $section, $merged ) ) {
$editPage->showEditForm( array( &$this, 'editCallback' ) );
return false;
}
return true;
}
/**
* A more efficient edit filter callback based on the text after section merging
* @param EditPage $editPage
* @param string $newtext
* @return bool
*/
function confirmEditMerged( $editPage, $newtext ) {
return $this->confirmEdit( $editPage, $newtext, false, true );
}
function confirmEditAPI( $editPage, $newtext, &$resultArr ) {
if ( !$this->doConfirmEdit( $editPage, $newtext, false, false ) ) {
$this->addCaptchaAPI( $resultArr );
return false;
}
return true;
}
/**
* Hook for user creation form submissions.
* @param User $u
* @param string $message
* @param Status $status
* @return bool true to continue, false to abort user creation
*/
function confirmUserCreate( $u, &$message, &$status = null ) {
if ( $this->needCreateAccountCaptcha() ) {
$this->trigger = "new account '" . $u->getName() . "'";
if ( !$this->passCaptcha() ) {
// For older MediaWiki
$message = wfMessage( 'captcha-createaccount-fail' )->text();
// For MediaWiki 1.23+
$status = Status::newFatal( 'captcha-createaccount-fail' );
return false;
}
}
return true;
}
/**
* Logic to check if we need to pass a captcha for the current user
* to create a new account, or not
*
* @return bool true to show captcha, false to skip captcha
*/
function needCreateAccountCaptcha() {
global $wgCaptchaTriggers, $wgUser;
if ( $wgCaptchaTriggers['createaccount'] ) {
if ( $wgUser->isAllowed( 'skipcaptcha' ) ) {
wfDebug( "ConfirmEdit: user group allows skipping captcha on account creation\n" );
return false;
}
if ( $this->isIPWhitelisted() ) {
return false;
}
return true;
}
return false;
}
/**
* Hook for user login form submissions.
* @param $u User
* @param $pass
* @param $retval
* @return bool true to continue, false to abort user creation
*/
function confirmUserLogin( $u, $pass, &$retval ) {
if ( $this->isBadLoginTriggered() ) {
if ( $this->isIPWhitelisted() )
return true;
$this->trigger = "post-badlogin login '" . $u->getName() . "'";
if ( !$this->passCaptcha() ) {
// Emulate a bad-password return to confuse the shit out of attackers
$retval = LoginForm::WRONG_PASS;
return false;
}
}
return true;
}
/**
* Check the captcha on Special:EmailUser
* @param $from MailAddress
* @param $to MailAddress
* @param $subject String
* @param $text String
* @param $error String reference
* @return Bool true to continue saving, false to abort and show a captcha form
*/
function confirmEmailUser( $from, $to, $subject, $text, &$error ) {
global $wgCaptchaTriggers, $wgUser;
if ( $wgCaptchaTriggers['sendemail'] ) {
if ( $wgUser->isAllowed( 'skipcaptcha' ) ) {
wfDebug( "ConfirmEdit: user group allows skipping captcha on email sending\n" );
return true;
}
if ( $this->isIPWhitelisted() )
return true;
if ( defined( 'MW_API' ) ) {
# API mode
# Asking for captchas in the API is really silly
$error = wfMessage( 'captcha-disabledinapi' )->text();
return false;
}
$this->trigger = "{$wgUser->getName()} sending email";
if ( !$this->passCaptcha() ) {
$error = wfMessage( 'captcha-sendemail-fail' )->text();
return false;
}
}
return true;
}
/**
* @param $module ApiBase
* @return bool
*/
protected function isAPICaptchaModule( $module ) {
return $module instanceof ApiEditPage || $module instanceof ApiCreateAccount;
}
/**
* @param $module ApiBase
* @param $params array
* @param $flags int
* @return bool
*/
public function APIGetAllowedParams( &$module, &$params, $flags ) {
if ( $flags && $this->isAPICaptchaModule( $module ) ) {
$params['captchaword'] = null;
$params['captchaid'] = null;
}
return true;
}
/**
* @param $module ApiBase
* @param $desc array
* @return bool
*/
public function APIGetParamDescription( &$module, &$desc ) {
if ( $this->isAPICaptchaModule( $module ) ) {
$desc['captchaid'] = 'CAPTCHA ID from previous request';
$desc['captchaword'] = 'Answer to the CAPTCHA';
}
return true;
}
/**
* Given a required captcha run, test form input for correct
* input on the open session.
* @return bool if passed, false if failed or new session
*/
function passCaptcha() {
$info = $this->retrieveCaptcha();
if ( $info ) {
global $wgRequest;
if ( $this->keyMatch( $wgRequest->getVal( 'wpCaptchaWord' ), $info ) ) {
$this->log( "passed" );
$this->clearCaptcha( $info );
return true;
} else {
$this->clearCaptcha( $info );
$this->log( "bad form input" );
return false;
}
} else {
$this->log( "new captcha session" );
return false;
}
}
/**
* Log the status and any triggering info for debugging or statistics
* @param string $message
*/
function log( $message ) {
wfDebugLog( 'captcha', 'ConfirmEdit: ' . $message . '; ' . $this->trigger );
}
/**
* Generate a captcha session ID and save the info in PHP's session storage.
* (Requires the user to have cookies enabled to get through the captcha.)
*
* A random ID is used so legit users can make edits in multiple tabs or
* windows without being unnecessarily hobbled by a serial order requirement.
* Pass the returned id value into the edit form as wpCaptchaId.
*
* @param array $info data to store
* @return string captcha ID key
*/
function storeCaptcha( $info ) {
if ( !isset( $info['index'] ) ) {
// Assign random index if we're not udpating
$info['index'] = strval( mt_rand() );
}
CaptchaStore::get()->store( $info['index'], $info );
return $info['index'];
}
/**
* Fetch this session's captcha info.
* @return mixed array of info, or false if missing
*/
function retrieveCaptcha() {
global $wgRequest;
$index = $wgRequest->getVal( 'wpCaptchaId' );
return CaptchaStore::get()->retrieve( $index );
}
/**
* Clear out existing captcha info from the session, to ensure
* it can't be reused.
*/
function clearCaptcha( $info ) {
CaptchaStore::get()->clear( $info['index'] );
}
/**
* Retrieve the current version of the page or section being edited...
* @param EditPage $editPage
* @param string $section
* @return string
* @access private
*/
function loadText( $editPage, $section ) {
$rev = Revision::newFromTitle( $editPage->mTitle, false, Revision::READ_LATEST );
if ( is_null( $rev ) ) {
return "";
} else {
$text = $rev->getText();
if ( $section != '' ) {
global $wgParser;
return $wgParser->getSection( $text, $section );
} else {
return $text;
}
}
}
/**
* Extract a list of all recognized HTTP links in the text.
* @param $editpage EditPage
* @param $text string
* @return array of strings
*/
function findLinks( &$editpage, $text ) {
global $wgParser, $wgUser;
$options = new ParserOptions();
$text = $wgParser->preSaveTransform( $text, $editpage->mTitle, $wgUser, $options );
$out = $wgParser->parse( $text, $editpage->mTitle, $options );
return array_keys( $out->getExternalLinks() );
}
/**
* Show a page explaining what this wacky thing is.
*/
function showHelp() {
global $wgOut;
$wgOut->setPageTitle( wfMessage( 'captchahelp-title' )->text() );
$wgOut->addWikiMsg( 'captchahelp-text' );
if ( CaptchaStore::get()->cookiesNeeded() ) {
$wgOut->addWikiMsg( 'captchahelp-cookies-needed' );
}
}
/**
* Pass API captcha parameters on to the login form when using
* API account creation.
*
* @param ApiCreateAccount $apiModule
* @param LoginForm $loginForm
* @return hook return value
*/
function addNewAccountApiForm( $apiModule, $loginForm ) {
global $wgRequest;
$main = $apiModule->getMain();
$id = $main->getVal( 'captchaid' );
if ( $id ) {
$wgRequest->setVal( 'wpCaptchaId', $id );
// Suppress "unrecognized parameter" warning:
$main->getVal( 'wpCaptchaId' );
}
$word = $main->getVal( 'captchaword' );
if ( $word ) {
$wgRequest->setVal( 'wpCaptchaWord', $word );
// Suppress "unrecognized parameter" warning:
$main->getVal( 'wpCaptchaWord' );
}
return true;
}
/**
* Pass extra data back in API results for account creation.
*
* @param ApiCreateAccount $apiModule
* @param LoginForm &loginForm
* @param array &$params
* @return hook return value
*/
function addNewAccountApiResult( $apiModule, $loginPage, &$result ) {
if ( $result['result'] !== 'success' && $this->needCreateAccountCaptcha() ) {
$this->addCaptchaAPI( $result );
}
return true;
}
}