RequestContext::exportSession() should only export persisted session IDs

[mediawiki.git] / includes / specials / SpecialUserlogin.php

<?php
/**
 * Implements Special:UserLogin
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program; if not, write to the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 * http://www.gnu.org/copyleft/gpl.html
 *
 * @file
 * @ingroup SpecialPage
 */
use MediaWiki\Logger\LoggerFactory;
use MediaWiki\Session\SessionManager;

/**
 * Implements Special:UserLogin
 *
 * @ingroup SpecialPage
 */
class LoginForm extends SpecialPage {
        const SUCCESS = 0;
        const NO_NAME = 1;
        const ILLEGAL = 2;
        const WRONG_PLUGIN_PASS = 3;
        const NOT_EXISTS = 4;
        const WRONG_PASS = 5;
        const EMPTY_PASS = 6;
        const RESET_PASS = 7;
        const ABORTED = 8;
        const CREATE_BLOCKED = 9;
        const THROTTLED = 10;
        const USER_BLOCKED = 11;
        const NEED_TOKEN = 12;
        const WRONG_TOKEN = 13;
        const USER_MIGRATED = 14;

        public static $statusCodes = array(
                self::SUCCESS => 'success',
                self::NO_NAME => 'no_name',
                self::ILLEGAL => 'illegal',
                self::WRONG_PLUGIN_PASS => 'wrong_plugin_pass',
                self::NOT_EXISTS => 'not_exists',
                self::WRONG_PASS => 'wrong_pass',
                self::EMPTY_PASS => 'empty_pass',
                self::RESET_PASS => 'reset_pass',
                self::ABORTED => 'aborted',
                self::CREATE_BLOCKED => 'create_blocked',
                self::THROTTLED => 'throttled',
                self::USER_BLOCKED => 'user_blocked',
                self::NEED_TOKEN => 'need_token',
                self::WRONG_TOKEN => 'wrong_token',
                self::USER_MIGRATED => 'user_migrated',
        );

        /**
         * Valid error and warning messages
         *
         * Special:Userlogin can show an error or warning message on the form when
         * coming from another page. This is done via the ?error= or ?warning= GET
         * parameters.
         *
         * This array is the list of valid message keys. All other values will be
         * ignored.
         *
         * @since 1.24
         * @var string[]
         */
        public static $validErrorMessages = array(
                'exception-nologin-text',
                'watchlistanontext',
                'changeemail-no-info',
                'resetpass-no-info',
                'confirmemail_needlogin',
                'prefsnologintext2',
        );

        public $mAbortLoginErrorMsg = null;

        protected $mUsername;
        protected $mPassword;
        protected $mRetype;
        protected $mReturnTo;
        protected $mCookieCheck;
        protected $mPosted;
        protected $mAction;
        protected $mCreateaccount;
        protected $mCreateaccountMail;
        protected $mLoginattempt;
        protected $mRemember;
        protected $mEmail;
        protected $mDomain;
        protected $mLanguage;
        protected $mSkipCookieCheck;
        protected $mReturnToQuery;
        protected $mToken;
        protected $mStickHTTPS;
        protected $mType;
        protected $mReason;
        protected $mRealName;
        protected $mEntryError = '';
        protected $mEntryErrorType = 'error';

        private $mTempPasswordUsed;
        private $mLoaded = false;
        private $mSecureLoginUrl;

        /** @var WebRequest */
        private $mOverrideRequest = null;

        /** @var WebRequest Effective request; set at the beginning of load */
        private $mRequest = null;

        /**
         * @param WebRequest $request
         */
        public function __construct( $request = null ) {
                global $wgUseMediaWikiUIEverywhere;
                parent::__construct( 'Userlogin' );

                $this->mOverrideRequest = $request;
                // Override UseMediaWikiEverywhere to true, to force login and create form to use mw ui
                $wgUseMediaWikiUIEverywhere = true;
        }

        public function doesWrites() {
                return true;
        }

        /**
         * Returns an array of all valid error messages.
         *
         * @return array
         */
        public static function getValidErrorMessages() {
                static $messages = null;
                if ( !$messages ) {
                        $messages = self::$validErrorMessages;
                        Hooks::run( 'LoginFormValidErrorMessages', array( &$messages ) );
                }

                return $messages;
        }

        /**
         * Loader
         */
        function load() {
                global $wgAuth, $wgHiddenPrefs, $wgEnableEmail;

                if ( $this->mLoaded ) {
                        return;
                }
                $this->mLoaded = true;

                if ( $this->mOverrideRequest === null ) {
                        $request = $this->getRequest();
                } else {
                        $request = $this->mOverrideRequest;
                }
                $this->mRequest = $request;

                $this->mType = $request->getText( 'type' );
                $this->mUsername = $request->getText( 'wpName' );
                $this->mPassword = $request->getText( 'wpPassword' );
                $this->mRetype = $request->getText( 'wpRetype' );
                $this->mDomain = $request->getText( 'wpDomain' );
                $this->mReason = $request->getText( 'wpReason' );
                $this->mCookieCheck = $request->getVal( 'wpCookieCheck' );
                $this->mPosted = $request->wasPosted();
                $this->mCreateaccountMail = $request->getCheck( 'wpCreateaccountMail' )
                        && $wgEnableEmail;
                $this->mCreateaccount = $request->getCheck( 'wpCreateaccount' ) && !$this->mCreateaccountMail;
                $this->mLoginattempt = $request->getCheck( 'wpLoginattempt' );
                $this->mAction = $request->getVal( 'action' );
                $this->mRemember = $request->getCheck( 'wpRemember' );
                $this->mFromHTTP = $request->getBool( 'fromhttp', false )
                        || $request->getBool( 'wpFromhttp', false );
                $this->mStickHTTPS = ( !$this->mFromHTTP && $request->getProtocol() === 'https' )
                        || $request->getBool( 'wpForceHttps', false );
                $this->mLanguage = $request->getText( 'uselang' );
                $this->mSkipCookieCheck = $request->getCheck( 'wpSkipCookieCheck' );
                $this->mToken = $this->mType == 'signup'
                        ? $request->getVal( 'wpCreateaccountToken' )
                        : $request->getVal( 'wpLoginToken' );
                $this->mReturnTo = $request->getVal( 'returnto', '' );
                $this->mReturnToQuery = $request->getVal( 'returntoquery', '' );

                // Show an error or warning passed on from a previous page
                $entryError = $this->msg( $request->getVal( 'error', '' ) );
                $entryWarning = $this->msg( $request->getVal( 'warning', '' ) );
                // bc: provide login link as a parameter for messages where the translation
                // was not updated
                $loginreqlink = Linker::linkKnown(
                        $this->getPageTitle(),
                        $this->msg( 'loginreqlink' )->escaped(),
                        array(),
                        array(
                                'returnto' => $this->mReturnTo,
                                'returntoquery' => $this->mReturnToQuery,
                                'uselang' => $this->mLanguage,
                                'fromhttp' => $this->mFromHTTP ? '1' : '0',
                        )
                );

                // Only show valid error or warning messages.
                if ( $entryError->exists()
                        && in_array( $entryError->getKey(), self::getValidErrorMessages() )
                ) {
                        $this->mEntryErrorType = 'error';
                        $this->mEntryError = $entryError->rawParams( $loginreqlink )->parse();

                } elseif ( $entryWarning->exists()
                        && in_array( $entryWarning->getKey(), self::getValidErrorMessages() )
                ) {
                        $this->mEntryErrorType = 'warning';
                        $this->mEntryError = $entryWarning->rawParams( $loginreqlink )->parse();
                }

                if ( $wgEnableEmail ) {
                        $this->mEmail = $request->getText( 'wpEmail' );
                } else {
                        $this->mEmail = '';
                }
                if ( !in_array( 'realname', $wgHiddenPrefs ) ) {
                        $this->mRealName = $request->getText( 'wpRealName' );
                } else {
                        $this->mRealName = '';
                }

                if ( !$wgAuth->validDomain( $this->mDomain ) ) {
                        $this->mDomain = $wgAuth->getDomain();
                }
                $wgAuth->setDomain( $this->mDomain );

                # 1. When switching accounts, it sucks to get automatically logged out
                # 2. Do not return to PasswordReset after a successful password change
                #    but goto Wiki start page (Main_Page) instead ( bug 33997 )
                $returnToTitle = Title::newFromText( $this->mReturnTo );
                if ( is_object( $returnToTitle )
                        && ( $returnToTitle->isSpecial( 'Userlogout' )
                                || $returnToTitle->isSpecial( 'PasswordReset' ) )
                ) {
                        $this->mReturnTo = '';
                        $this->mReturnToQuery = '';
                }
        }

        function getDescription() {
                if ( $this->mType === 'signup' ) {
                        return $this->msg( 'createaccount' )->text();
                } else {
                        return $this->msg( 'login' )->text();
                }
        }

        /**
         * @param string|null $subPage
         */
        public function execute( $subPage ) {
                // Make sure session is persisted
                $session = MediaWiki\Session\SessionManager::getGlobalSession();
                $session->persist();

                $this->load();

                // Check for [[Special:Userlogin/signup]]. This affects form display and
                // page title.
                if ( $subPage == 'signup' ) {
                        $this->mType = 'signup';
                }
                $this->setHeaders();

                // Make sure it's possible to log in
                if ( $this->mType !== 'signup' && !$session->canSetUser() ) {
                        throw new ErrorPageError(
                                'cannotloginnow-title',
                                'cannotloginnow-text',
                                array(
                                        $session->getProvider()->describe( RequestContext::getMain()->getLanguage() )
                                )
                        );
                }

                /**
                 * In the case where the user is already logged in, and was redirected to
                 * the login form from a page that requires login, do not show the login
                 * page. The use case scenario for this is when a user opens a large number
                 * of tabs, is redirected to the login page on all of them, and then logs
                 * in on one, expecting all the others to work properly.
                 *
                 * However, do show the form if it was visited intentionally (no 'returnto'
                 * is present). People who often switch between several accounts have grown
                 * accustomed to this behavior.
                 */
                if (
                        $this->mType !== 'signup' &&
                        !$this->mPosted &&
                        $this->getUser()->isLoggedIn() &&
                        ( $this->mReturnTo !== '' || $this->mReturnToQuery !== '' )
                ) {
                        $this->successfulLogin();
                }

                // If logging in and not on HTTPS, either redirect to it or offer a link.
                global $wgSecureLogin;
                if ( $this->mRequest->getProtocol() !== 'https' ) {
                        $title = $this->getFullTitle();
                        $query = array(
                                'returnto' => $this->mReturnTo !== '' ? $this->mReturnTo : null,
                                'returntoquery' => $this->mReturnToQuery !== '' ?
                                        $this->mReturnToQuery : null,
                                'title' => null,
                                ( $this->mEntryErrorType === 'error' ? 'error' : 'warning' ) => $this->mEntryError,
                        ) + $this->mRequest->getQueryValues();
                        $url = $title->getFullURL( $query, false, PROTO_HTTPS );
                        if ( $wgSecureLogin
                                && wfCanIPUseHTTPS( $this->getRequest()->getIP() )
                                && !$this->mFromHTTP ) // Avoid infinite redirect
                        {
                                $url = wfAppendQuery( $url, 'fromhttp=1' );
                                $this->getOutput()->redirect( $url );
                                // Since we only do this redir to change proto, always vary
                                $this->getOutput()->addVaryHeader( 'X-Forwarded-Proto' );

                                return;
                        } else {
                                // A wiki without HTTPS login support should set $wgServer to
                                // http://somehost, in which case the secure URL generated
                                // above won't actually start with https://
                                if ( substr( $url, 0, 8 ) === 'https://' ) {
                                        $this->mSecureLoginUrl = $url;
                                }
                        }
                }

                if ( !is_null( $this->mCookieCheck ) ) {
                        $this->onCookieRedirectCheck( $this->mCookieCheck );

                        return;
                } elseif ( $this->mPosted ) {
                        if ( $this->mCreateaccount ) {
                                $this->addNewAccount();

                                return;
                        } elseif ( $this->mCreateaccountMail ) {
                                $this->addNewAccountMailPassword();

                                return;
                        } elseif ( ( 'submitlogin' == $this->mAction ) || $this->mLoginattempt ) {
                                $this->processLogin();

                                return;
                        }
                }
                $this->mainLoginForm( $this->mEntryError, $this->mEntryErrorType );
        }

        /**
         * @private
         */
        function addNewAccountMailPassword() {
                if ( $this->mEmail == '' ) {
                        $this->mainLoginForm( $this->msg( 'noemailcreate' )->escaped() );

                        return;
                }

                $status = $this->addNewAccountInternal();
                LoggerFactory::getInstance( 'authmanager' )->info(
                        'Account creation attempt with mailed password',
                        array( 'event' => 'accountcreation', 'status' => $status )
                );
                if ( !$status->isGood() ) {
                        $error = $status->getMessage();
                        $this->mainLoginForm( $error->toString() );

                        return;
                }

                /** @var User $u */
                $u = $status->getValue();

                // Wipe the initial password and mail a temporary one
                $u->setPassword( null );
                $u->saveSettings();
                $result = $this->mailPasswordInternal( $u, false, 'createaccount-title', 'createaccount-text' );

                Hooks::run( 'AddNewAccount', array( $u, true ) );
                $u->addNewUserLogEntry( 'byemail', $this->mReason );

                $out = $this->getOutput();
                $out->setPageTitle( $this->msg( 'accmailtitle' ) );

                if ( !$result->isGood() ) {
                        $this->mainLoginForm( $this->msg( 'mailerror', $result->getWikiText() )->text() );
                } else {
                        $out->addWikiMsg( 'accmailtext', $u->getName(), $u->getEmail() );
                        $this->executeReturnTo( 'success' );
                }
        }

        /**
         * @private
         * @return bool
         */
        function addNewAccount() {
                global $wgContLang, $wgUser, $wgEmailAuthentication, $wgLoginLanguageSelector;

                # Create the account and abort if there's a problem doing so
                $status = $this->addNewAccountInternal();
                LoggerFactory::getInstance( 'authmanager' )->info( 'Account creation attempt', array(
                        'event' => 'accountcreation',
                        'status' => $status,
                ) );

                if ( !$status->isGood() ) {
                        $error = $status->getMessage();
                        $this->mainLoginForm( $error->toString() );

                        return false;
                }

                $u = $status->getValue();

                # Only save preferences if the user is not creating an account for someone else.
                if ( $this->getUser()->isAnon() ) {
                        # If we showed up language selection links, and one was in use, be
                        # smart (and sensible) and save that language as the user's preference
                        if ( $wgLoginLanguageSelector && $this->mLanguage ) {
                                $u->setOption( 'language', $this->mLanguage );
                        } else {

                                # Otherwise the user's language preference defaults to $wgContLang,
                                # but it may be better to set it to their preferred $wgContLang variant,
                                # based on browser preferences or URL parameters.
                                $u->setOption( 'language', $wgContLang->getPreferredVariant() );
                        }
                        if ( $wgContLang->hasVariants() ) {
                                $u->setOption( 'variant', $wgContLang->getPreferredVariant() );
                        }
                }

                $out = $this->getOutput();

                # Send out an email authentication message if needed
                if ( $wgEmailAuthentication && Sanitizer::validateEmail( $u->getEmail() ) ) {
                        $status = $u->sendConfirmationMail();
                        if ( $status->isGood() ) {
                                $out->addWikiMsg( 'confirmemail_oncreate' );
                        } else {
                                $out->addWikiText( $status->getWikiText( 'confirmemail_sendfailed' ) );
                        }
                }

                # Save settings (including confirmation token)
                $u->saveSettings();

                # If not logged in, assume the new account as the current one and set
                # session cookies then show a "welcome" message or a "need cookies"
                # message as needed
                if ( $this->getUser()->isAnon() ) {
                        $u->setCookies();
                        $wgUser = $u;
                        // This should set it for OutputPage and the Skin
                        // which is needed or the personal links will be
                        // wrong.
                        $this->getContext()->setUser( $u );
                        Hooks::run( 'AddNewAccount', array( $u, false ) );
                        $u->addNewUserLogEntry( 'create' );
                        if ( $this->hasSessionCookie() ) {
                                $this->successfulCreation();
                        } else {
                                $this->cookieRedirectCheck( 'new' );
                        }
                } else {
                        # Confirm that the account was created
                        $out->setPageTitle( $this->msg( 'accountcreated' ) );
                        $out->addWikiMsg( 'accountcreatedtext', $u->getName() );
                        $out->addReturnTo( $this->getPageTitle() );
                        Hooks::run( 'AddNewAccount', array( $u, false ) );
                        $u->addNewUserLogEntry( 'create2', $this->mReason );
                }

                return true;
        }

        /**
         * Make a new user account using the loaded data.
         * @private
         * @throws PermissionsError|ReadOnlyError
         * @return Status
         */
        public function addNewAccountInternal() {
                global $wgAuth, $wgAccountCreationThrottle, $wgEmailConfirmToEdit;

                // If the user passes an invalid domain, something is fishy
                if ( !$wgAuth->validDomain( $this->mDomain ) ) {
                        return Status::newFatal( 'wrongpassword' );
                }

                // If we are not allowing users to login locally, we should be checking
                // to see if the user is actually able to authenticate to the authenti-
                // cation server before they create an account (otherwise, they can
                // create a local account and login as any domain user). We only need
                // to check this for domains that aren't local.
                if ( 'local' != $this->mDomain && $this->mDomain != '' ) {
                        if (
                                !$wgAuth->canCreateAccounts() &&
                                (
                                        !$wgAuth->userExists( $this->mUsername ) ||
                                        !$wgAuth->authenticate( $this->mUsername, $this->mPassword )
                                )
                        ) {
                                return Status::newFatal( 'wrongpassword' );
                        }
                }

                if ( wfReadOnly() ) {
                        throw new ReadOnlyError;
                }

                # Request forgery checks.
                if ( !self::getCreateaccountToken() ) {
                        self::setCreateaccountToken();

                        return Status::newFatal( 'nocookiesfornew' );
                }

                # The user didn't pass a createaccount token
                if ( !$this->mToken ) {
                        return Status::newFatal( 'sessionfailure' );
                }

                # Validate the createaccount token
                if ( $this->mToken !== self::getCreateaccountToken() ) {
                        return Status::newFatal( 'sessionfailure' );
                }

                # Check permissions
                $currentUser = $this->getUser();
                $creationBlock = $currentUser->isBlockedFromCreateAccount();
                if ( !$currentUser->isAllowed( 'createaccount' ) ) {
                        throw new PermissionsError( 'createaccount' );
                } elseif ( $creationBlock instanceof Block ) {
                        // Throws an ErrorPageError.
                        $this->userBlockedMessage( $creationBlock );

                        // This should never be reached.
                        return false;
                }

                # Include checks that will include GlobalBlocking (Bug 38333)
                $permErrors = $this->getPageTitle()->getUserPermissionsErrors(
                        'createaccount',
                        $currentUser,
                        true
                );

                if ( count( $permErrors ) ) {
                        throw new PermissionsError( 'createaccount', $permErrors );
                }

                $ip = $this->getRequest()->getIP();
                if ( $currentUser->isDnsBlacklisted( $ip, true /* check $wgProxyWhitelist */ ) ) {
                        return Status::newFatal( 'sorbs_create_account_reason' );
                }

                # Now create a dummy user ($u) and check if it is valid
                $u = User::newFromName( $this->mUsername, 'creatable' );
                if ( !$u ) {
                        return Status::newFatal( 'noname' );
                }

                $cache = ObjectCache::getLocalClusterInstance();
                # Make sure the user does not exist already
                $lock = $cache->getScopedLock( $cache->makeGlobalKey( 'account', md5( $this->mUsername ) ) );
                if ( !$lock ) {
                        return Status::newFatal( 'usernameinprogress' );
                } elseif ( $u->idForName( User::READ_LOCKING ) ) {
                        return Status::newFatal( 'userexists' );
                }

                if ( $this->mCreateaccountMail ) {
                        # do not force a password for account creation by email
                        # set invalid password, it will be replaced later by a random generated password
                        $this->mPassword = null;
                } else {
                        if ( $this->mPassword !== $this->mRetype ) {
                                return Status::newFatal( 'badretype' );
                        }

                        # check for password validity, return a fatal Status if invalid
                        $validity = $u->checkPasswordValidity( $this->mPassword, 'create' );
                        if ( !$validity->isGood() ) {
                                $validity->ok = false; // make sure this Status is fatal
                                return $validity;
                        }
                }

                # if you need a confirmed email address to edit, then obviously you
                # need an email address.
                if ( $wgEmailConfirmToEdit && strval( $this->mEmail ) === '' ) {
                        return Status::newFatal( 'noemailtitle' );
                }

                if ( strval( $this->mEmail ) !== '' && !Sanitizer::validateEmail( $this->mEmail ) ) {
                        return Status::newFatal( 'invalidemailaddress' );
                }

                # Set some additional data so the AbortNewAccount hook can be used for
                # more than just username validation
                $u->setEmail( $this->mEmail );
                $u->setRealName( $this->mRealName );

                $abortError = '';
                $abortStatus = null;
                if ( !Hooks::run( 'AbortNewAccount', array( $u, &$abortError, &$abortStatus ) ) ) {
                        // Hook point to add extra creation throttles and blocks
                        wfDebug( "LoginForm::addNewAccountInternal: a hook blocked creation\n" );
                        if ( $abortStatus === null ) {
                                // Report back the old string as a raw message status.
                                // This will report the error back as 'createaccount-hook-aborted'
                                // with the given string as the message.
                                // To return a different error code, return a Status object.
                                $abortError = new Message( 'createaccount-hook-aborted', array( $abortError ) );
                                $abortError->text();

                                return Status::newFatal( $abortError );
                        } else {
                                // For MediaWiki 1.23+ and updated hooks, return the Status object
                                // returned from the hook.
                                return $abortStatus;
                        }
                }

                // Hook point to check for exempt from account creation throttle
                if ( !Hooks::run( 'ExemptFromAccountCreationThrottle', array( $ip ) ) ) {
                        wfDebug( "LoginForm::exemptFromAccountCreationThrottle: a hook " .
                                "allowed account creation w/o throttle\n" );
                } else {
                        if ( ( $wgAccountCreationThrottle && $currentUser->isPingLimitable() ) ) {
                                $key = wfMemcKey( 'acctcreate', 'ip', $ip );
                                $value = $cache->get( $key );
                                if ( !$value ) {
                                        $cache->set( $key, 0, $cache::TTL_DAY );
                                }
                                if ( $value >= $wgAccountCreationThrottle ) {
                                        return Status::newFatal( 'acct_creation_throttle_hit', $wgAccountCreationThrottle );
                                }
                                $cache->incr( $key );
                        }
                }

                if ( !$wgAuth->addUser( $u, $this->mPassword, $this->mEmail, $this->mRealName ) ) {
                        return Status::newFatal( 'externaldberror' );
                }

                self::clearCreateaccountToken();

                return $this->initUser( $u, false );
        }

        /**
         * Actually add a user to the database.
         * Give it a User object that has been initialised with a name.
         *
         * @param User $u
         * @param bool $autocreate True if this is an autocreation via auth plugin
         * @return Status Status object, with the User object in the value member on success
         * @private
         */
        function initUser( $u, $autocreate ) {
                global $wgAuth;

                $status = $u->addToDatabase();
                if ( !$status->isOK() ) {
                        return $status;
                }

                if ( $wgAuth->allowPasswordChange() ) {
                        $u->setPassword( $this->mPassword );
                }

                $u->setEmail( $this->mEmail );
                $u->setRealName( $this->mRealName );
                $u->setToken();

                Hooks::run( 'LocalUserCreated', array( $u, $autocreate ) );
                $oldUser = $u;
                $wgAuth->initUser( $u, $autocreate );
                if ( $oldUser !== $u ) {
                        wfWarn( get_class( $wgAuth ) . '::initUser() replaced the user object' );
                }

                $u->saveSettings();

                // Update user count
                DeferredUpdates::addUpdate( new SiteStatsUpdate( 0, 0, 0, 0, 1 ) );

                // Watch user's userpage and talk page
                $u->addWatch( $u->getUserPage(), WatchedItem::IGNORE_USER_RIGHTS );

                return Status::newGood( $u );
        }

        /**
         * Internally authenticate the login request.
         *
         * This may create a local account as a side effect if the
         * authentication plugin allows transparent local account
         * creation.
         * @return int
         */
        public function authenticateUserData() {
                global $wgUser, $wgAuth;

                $this->load();

                if ( $this->mUsername == '' ) {
                        return self::NO_NAME;
                }

                // We require a login token to prevent login CSRF
                // Handle part of this before incrementing the throttle so
                // token-less login attempts don't count towards the throttle
                // but wrong-token attempts do.

                // If the user doesn't have a login token yet, set one.
                if ( !self::getLoginToken() ) {
                        self::setLoginToken();

                        return self::NEED_TOKEN;
                }
                // If the user didn't pass a login token, tell them we need one
                if ( !$this->mToken ) {
                        return self::NEED_TOKEN;
                }

                $throttleCount = self::incLoginThrottle( $this->mUsername );
                if ( $throttleCount === true ) {
                        return self::THROTTLED;
                }

                // Validate the login token
                if ( $this->mToken !== self::getLoginToken() ) {
                        return self::WRONG_TOKEN;
                }

                // Load the current user now, and check to see if we're logging in as
                // the same name. This is necessary because loading the current user
                // (say by calling getName()) calls the UserLoadFromSession hook, which
                // potentially creates the user in the database. Until we load $wgUser,
                // checking for user existence using User::newFromName($name)->getId() below
                // will effectively be using stale data.
                if ( $this->getUser()->getName() === $this->mUsername ) {
                        wfDebug( __METHOD__ . ": already logged in as {$this->mUsername}\n" );

                        return self::SUCCESS;
                }

                $u = User::newFromName( $this->mUsername );
                if ( $u === false ) {
                        return self::ILLEGAL;
                }

                $msg = null;
                // Give extensions a way to indicate the username has been updated,
                // rather than telling the user the account doesn't exist.
                if ( !Hooks::run( 'LoginUserMigrated', array( $u, &$msg ) ) ) {
                        $this->mAbortLoginErrorMsg = $msg;
                        return self::USER_MIGRATED;
                }

                if ( !User::isUsableName( $u->getName() ) ) {
                        return self::ILLEGAL;
                }

                $isAutoCreated = false;
                if ( $u->getID() == 0 ) {
                        $status = $this->attemptAutoCreate( $u );
                        if ( $status !== self::SUCCESS ) {
                                return $status;
                        } else {
                                $isAutoCreated = true;
                        }
                } else {
                        $u->load();
                }

                // Give general extensions, such as a captcha, a chance to abort logins
                $abort = self::ABORTED;
                if ( !Hooks::run( 'AbortLogin', array( $u, $this->mPassword, &$abort, &$msg ) ) ) {
                        if ( !in_array( $abort, array_keys( self::$statusCodes ), true ) ) {
                                throw new Exception( 'Invalid status code returned from AbortLogin hook: ' . $abort );
                        }
                        $this->mAbortLoginErrorMsg = $msg;
                        return $abort;
                }

                global $wgBlockDisablesLogin;
                if ( !$u->checkPassword( $this->mPassword ) ) {
                        if ( $u->checkTemporaryPassword( $this->mPassword ) ) {
                                /**
                                 * The e-mailed temporary password should not be used for actu-
                                 * al logins; that's a very sloppy habit, and insecure if an
                                 * attacker has a few seconds to click "search" on someone's
                                 * open mail reader.
                                 *
                                 * Allow it to be used only to reset the password a single time
                                 * to a new value, which won't be in the user's e-mail ar-
                                 * chives.
                                 *
                                 * For backwards compatibility, we'll still recognize it at the
                                 * login form to minimize surprises for people who have been
                                 * logging in with a temporary password for some time.
                                 *
                                 * As a side-effect, we can authenticate the user's e-mail ad-
                                 * dress if it's not already done, since the temporary password
                                 * was sent via e-mail.
                                 */
                                if ( !$u->isEmailConfirmed() && !wfReadOnly() ) {
                                        $u->confirmEmail();
                                        $u->saveSettings();
                                }

                                // At this point we just return an appropriate code/ indicating
                                // that the UI should show a password reset form; bot inter-
                                // faces etc will probably just fail cleanly here.
                                $this->mAbortLoginErrorMsg = 'resetpass-temp-emailed';
                                $this->mTempPasswordUsed = true;
                                $retval = self::RESET_PASS;
                        } else {
                                $retval = ( $this->mPassword == '' ) ? self::EMPTY_PASS : self::WRONG_PASS;
                        }
                } elseif ( $wgBlockDisablesLogin && $u->isBlocked() ) {
                        // If we've enabled it, make it so that a blocked user cannot login
                        $retval = self::USER_BLOCKED;
                } elseif ( $this->checkUserPasswordExpired( $u ) == 'hard' ) {
                        // Force reset now, without logging in
                        $retval = self::RESET_PASS;
                        $this->mAbortLoginErrorMsg = 'resetpass-expired';
                } else {
                        Hooks::run( 'UserLoggedIn', array( $u ) );
                        $oldUser = $u;
                        $wgAuth->updateUser( $u );
                        if ( $oldUser !== $u ) {
                                wfWarn( get_class( $wgAuth ) . '::updateUser() replaced the user object' );
                        }
                        $wgUser = $u;
                        // This should set it for OutputPage and the Skin
                        // which is needed or the personal links will be
                        // wrong.
                        $this->getContext()->setUser( $u );

                        // Please reset throttle for successful logins, thanks!
                        if ( $throttleCount ) {
                                self::clearLoginThrottle( $this->mUsername );
                        }

                        if ( $isAutoCreated ) {
                                // Must be run after $wgUser is set, for correct new user log
                                Hooks::run( 'AuthPluginAutoCreate', array( $u ) );
                        }

                        $retval = self::SUCCESS;
                }
                Hooks::run( 'LoginAuthenticateAudit', array( $u, $this->mPassword, $retval ) );

                return $retval;
        }

        /**
         * Increment the login attempt throttle hit count for the (username,current IP)
         * tuple unless the throttle was already reached.
         * @param string $username The user name
         * @return bool|int The integer hit count or True if it is already at the limit
         */
        public static function incLoginThrottle( $username ) {
                global $wgPasswordAttemptThrottle, $wgRequest;
                $username = trim( $username ); // sanity

                $throttleCount = 0;
                if ( is_array( $wgPasswordAttemptThrottle ) ) {
                        $throttleKey = wfMemcKey( 'password-throttle', $wgRequest->getIP(), md5( $username ) );
                        $count = $wgPasswordAttemptThrottle['count'];
                        $period = $wgPasswordAttemptThrottle['seconds'];

                        $cache = ObjectCache::getLocalClusterInstance();
                        $throttleCount = $cache->get( $throttleKey );
                        if ( !$throttleCount ) {
                                $cache->add( $throttleKey, 1, $period ); // start counter
                        } elseif ( $throttleCount < $count ) {
                                $cache->incr( $throttleKey );
                        } elseif ( $throttleCount >= $count ) {
                                return true;
                        }
                }

                return $throttleCount;
        }

        /**
         * Clear the login attempt throttle hit count for the (username,current IP) tuple.
         * @param string $username The user name
         * @return void
         */
        public static function clearLoginThrottle( $username ) {
                global $wgRequest;
                $username = trim( $username ); // sanity

                $throttleKey = wfMemcKey( 'password-throttle', $wgRequest->getIP(), md5( $username ) );
                ObjectCache::getLocalClusterInstance()->delete( $throttleKey );
        }

        /**
         * Attempt to automatically create a user on login. Only succeeds if there
         * is an external authentication method which allows it.
         *
         * @param User $user
         *
         * @return int Status code
         */
        function attemptAutoCreate( $user ) {
                global $wgAuth;

                if ( $this->getUser()->isBlockedFromCreateAccount() ) {
                        wfDebug( __METHOD__ . ": user is blocked from account creation\n" );

                        return self::CREATE_BLOCKED;
                }

                if ( !$wgAuth->autoCreate() ) {
                        return self::NOT_EXISTS;
                }

                if ( !$wgAuth->userExists( $user->getName() ) ) {
                        wfDebug( __METHOD__ . ": user does not exist\n" );

                        return self::NOT_EXISTS;
                }

                if ( !$wgAuth->authenticate( $user->getName(), $this->mPassword ) ) {
                        wfDebug( __METHOD__ . ": \$wgAuth->authenticate() returned false, aborting\n" );

                        return self::WRONG_PLUGIN_PASS;
                }

                $abortError = '';
                if ( !Hooks::run( 'AbortAutoAccount', array( $user, &$abortError ) ) ) {
                        // Hook point to add extra creation throttles and blocks
                        wfDebug( "LoginForm::attemptAutoCreate: a hook blocked creation: $abortError\n" );
                        $this->mAbortLoginErrorMsg = $abortError;

                        return self::ABORTED;
                }

                wfDebug( __METHOD__ . ": creating account\n" );
                $status = $this->initUser( $user, true );

                if ( !$status->isOK() ) {
                        $errors = $status->getErrorsByType( 'error' );
                        $this->mAbortLoginErrorMsg = $errors[0]['message'];

                        return self::ABORTED;
                }

                return self::SUCCESS;
        }

        function processLogin() {
                global $wgLang, $wgSecureLogin, $wgPasswordAttemptThrottle, $wgInvalidPasswordReset;

                $cache = ObjectCache::getLocalClusterInstance();
                $authRes = $this->authenticateUserData();
                switch ( $authRes ) {
                        case self::SUCCESS:
                                # We've verified now, update the real record
                                $user = $this->getUser();
                                $user->touch();

                                if ( $user->requiresHTTPS() ) {
                                        $this->mStickHTTPS = true;
                                }

                                if ( $wgSecureLogin && !$this->mStickHTTPS ) {
                                        $user->setCookies( $this->mRequest, false, $this->mRemember );
                                } else {
                                        $user->setCookies( $this->mRequest, null, $this->mRemember );
                                }
                                self::clearLoginToken();

                                // Reset the throttle
                                $request = $this->getRequest();
                                $key = wfMemcKey( 'password-throttle', $request->getIP(), md5( $this->mUsername ) );
                                $cache->delete( $key );

                                if ( $this->hasSessionCookie() || $this->mSkipCookieCheck ) {
                                        /* Replace the language object to provide user interface in
                                         * correct language immediately on this first page load.
                                         */
                                        $code = $request->getVal( 'uselang', $user->getOption( 'language' ) );
                                        $userLang = Language::factory( $code );
                                        $wgLang = $userLang;
                                        $this->getContext()->setLanguage( $userLang );
                                        // Reset SessionID on Successful login (bug 40995)
                                        $this->renewSessionId();
                                        if ( $this->checkUserPasswordExpired( $this->getUser() ) == 'soft' ) {
                                                $this->resetLoginForm( $this->msg( 'resetpass-expired-soft' ) );
                                        } elseif ( $wgInvalidPasswordReset
                                                && !$user->isValidPassword( $this->mPassword )
                                        ) {
                                                $status = $user->checkPasswordValidity(
                                                        $this->mPassword,
                                                        'login'
                                                );
                                                $this->resetLoginForm(
                                                        $status->getMessage( 'resetpass-validity-soft' )
                                                );
                                        } else {
                                                $this->successfulLogin();
                                        }
                                } else {
                                        $this->cookieRedirectCheck( 'login' );
                                }
                                break;

                        case self::NEED_TOKEN:
                                $error = $this->mAbortLoginErrorMsg ?: 'nocookiesforlogin';
                                $this->mainLoginForm( $this->msg( $error )->parse() );
                                break;
                        case self::WRONG_TOKEN:
                                $error = $this->mAbortLoginErrorMsg ?: 'sessionfailure';
                                $this->mainLoginForm( $this->msg( $error )->text() );
                                break;
                        case self::NO_NAME:
                        case self::ILLEGAL:
                                $error = $this->mAbortLoginErrorMsg ?: 'noname';
                                $this->mainLoginForm( $this->msg( $error )->text() );
                                break;
                        case self::WRONG_PLUGIN_PASS:
                                $error = $this->mAbortLoginErrorMsg ?: 'wrongpassword';
                                $this->mainLoginForm( $this->msg( $error )->text() );
                                break;
                        case self::NOT_EXISTS:
                                if ( $this->getUser()->isAllowed( 'createaccount' ) ) {
                                        $error = $this->mAbortLoginErrorMsg ?: 'nosuchuser';
                                        $this->mainLoginForm( $this->msg( $error,
                                                wfEscapeWikiText( $this->mUsername ) )->parse() );
                                } else {
                                        $error = $this->mAbortLoginErrorMsg ?: 'nosuchusershort';
                                        $this->mainLoginForm( $this->msg( $error,
                                                wfEscapeWikiText( $this->mUsername ) )->text() );
                                }
                                break;
                        case self::WRONG_PASS:
                                $error = $this->mAbortLoginErrorMsg ?: 'wrongpassword';
                                $this->mainLoginForm( $this->msg( $error )->text() );
                                break;
                        case self::EMPTY_PASS:
                                $error = $this->mAbortLoginErrorMsg ?: 'wrongpasswordempty';
                                $this->mainLoginForm( $this->msg( $error )->text() );
                                break;
                        case self::RESET_PASS:
                                $error = $this->mAbortLoginErrorMsg ?: 'resetpass_announce';
                                $this->resetLoginForm( $this->msg( $error ) );
                                break;
                        case self::CREATE_BLOCKED:
                                $this->userBlockedMessage( $this->getUser()->isBlockedFromCreateAccount() );
                                break;
                        case self::THROTTLED:
                                $error = $this->mAbortLoginErrorMsg ?: 'login-throttled';
                                $this->mainLoginForm( $this->msg( $error )
                                        ->params( $this->getLanguage()->formatDuration( $wgPasswordAttemptThrottle['seconds'] ) )
                                        ->text()
                                );
                                break;
                        case self::USER_BLOCKED:
                                $error = $this->mAbortLoginErrorMsg ?: 'login-userblocked';
                                $this->mainLoginForm( $this->msg( $error, $this->mUsername )->escaped() );
                                break;
                        case self::ABORTED:
                                $error = $this->mAbortLoginErrorMsg ?: 'login-abort-generic';
                                $this->mainLoginForm( $this->msg( $error,
                                                wfEscapeWikiText( $this->mUsername ) )->text() );
                                break;
                        case self::USER_MIGRATED:
                                $error = $this->mAbortLoginErrorMsg ?: 'login-migrated-generic';
                                $params = array();
                                if ( is_array( $error ) ) {
                                        $error = array_shift( $this->mAbortLoginErrorMsg );
                                        $params = $this->mAbortLoginErrorMsg;
                                }
                                $this->mainLoginForm( $this->msg( $error, $params )->text() );
                                break;
                        default:
                                throw new MWException( 'Unhandled case value' );
                }

                LoggerFactory::getInstance( 'authmanager' )->info( 'Login attempt', array(
                        'event' => 'login',
                        'successful' => $authRes === self::SUCCESS,
                        'status' => LoginForm::$statusCodes[$authRes],
                ) );
        }

        /**
         * Show the Special:ChangePassword form, with custom message
         * @param Message $msg
         */
        protected function resetLoginForm( Message $msg ) {
                // Allow hooks to explain this password reset in more detail
                Hooks::run( 'LoginPasswordResetMessage', array( &$msg, $this->mUsername ) );
                $reset = new SpecialChangePassword();
                $derivative = new DerivativeContext( $this->getContext() );
                $derivative->setTitle( $reset->getPageTitle() );
                $reset->setContext( $derivative );
                if ( !$this->mTempPasswordUsed ) {
                        $reset->setOldPasswordMessage( 'oldpassword' );
                }
                $reset->setChangeMessage( $msg );
                $reset->execute( null );
        }

        /**
         * @param User $u
         * @param bool $throttle
         * @param string $emailTitle Message name of email title
         * @param string $emailText Message name of email text
         * @return Status
         */
        function mailPasswordInternal( $u, $throttle = true, $emailTitle = 'passwordremindertitle',
                $emailText = 'passwordremindertext'
        ) {
                global $wgNewPasswordExpiry, $wgMinimalPasswordLength;

                if ( $u->getEmail() == '' ) {
                        return Status::newFatal( 'noemail', $u->getName() );
                }
                $ip = $this->getRequest()->getIP();
                if ( !$ip ) {
                        return Status::newFatal( 'badipaddress' );
                }

                $currentUser = $this->getUser();
                Hooks::run( 'User::mailPasswordInternal', array( &$currentUser, &$ip, &$u ) );

                $np = PasswordFactory::generateRandomPasswordString( $wgMinimalPasswordLength );
                $u->setNewpassword( $np, $throttle );
                $u->saveSettings();
                $userLanguage = $u->getOption( 'language' );

                $mainPage = Title::newMainPage();
                $mainPageUrl = $mainPage->getCanonicalURL();

                $m = $this->msg( $emailText, $ip, $u->getName(), $np, '<' . $mainPageUrl . '>',
                        round( $wgNewPasswordExpiry / 86400 ) )->inLanguage( $userLanguage )->text();
                $result = $u->sendMail( $this->msg( $emailTitle )->inLanguage( $userLanguage )->text(), $m );

                return $result;
        }

        /**
         * Run any hooks registered for logins, then HTTP redirect to
         * $this->mReturnTo (or Main Page if that's undefined).  Formerly we had a
         * nice message here, but that's really not as useful as just being sent to
         * wherever you logged in from.  It should be clear that the action was
         * successful, given the lack of error messages plus the appearance of your
         * name in the upper right.
         *
         * @private
         */
        function successfulLogin() {
                # Run any hooks; display injected HTML if any, else redirect
                $currentUser = $this->getUser();
                $injected_html = '';
                Hooks::run( 'UserLoginComplete', array( &$currentUser, &$injected_html ) );

                if ( $injected_html !== '' ) {
                        $this->displaySuccessfulAction( 'success', $this->msg( 'loginsuccesstitle' ),
                                'loginsuccess', $injected_html );
                } else {
                        $this->executeReturnTo( 'successredirect' );
                }
        }

        /**
         * Run any hooks registered for logins, then display a message welcoming
         * the user.
         *
         * @private
         */
        function successfulCreation() {
                # Run any hooks; display injected HTML
                $currentUser = $this->getUser();
                $injected_html = '';
                $welcome_creation_msg = 'welcomecreation-msg';

                Hooks::run( 'UserLoginComplete', array( &$currentUser, &$injected_html ) );

                /**
                 * Let any extensions change what message is shown.
                 * @see https://www.mediawiki.org/wiki/Manual:Hooks/BeforeWelcomeCreation
                 * @since 1.18
                 */
                Hooks::run( 'BeforeWelcomeCreation', array( &$welcome_creation_msg, &$injected_html ) );

                $this->displaySuccessfulAction(
                        'signup',
                        $this->msg( 'welcomeuser', $this->getUser()->getName() ),
                        $welcome_creation_msg, $injected_html
                );
        }

        /**
         * Display a "successful action" page.
         *
         * @param string $type Condition of return to; see `executeReturnTo`
         * @param string|Message $title Page's title
         * @param string $msgname
         * @param string $injected_html
         */
        private function displaySuccessfulAction( $type, $title, $msgname, $injected_html ) {
                $out = $this->getOutput();
                $out->setPageTitle( $title );
                if ( $msgname ) {
                        $out->addWikiMsg( $msgname, wfEscapeWikiText( $this->getUser()->getName() ) );
                }

                $out->addHTML( $injected_html );

                $this->executeReturnTo( $type );
        }

        /**
         * Output a message that informs the user that they cannot create an account because
         * there is a block on them or their IP which prevents account creation.  Note that
         * User::isBlockedFromCreateAccount(), which gets this block, ignores the 'hardblock'
         * setting on blocks (bug 13611).
         * @param Block $block The block causing this error
         * @throws ErrorPageError
         */
        function userBlockedMessage( Block $block ) {
                # Let's be nice about this, it's likely that this feature will be used
                # for blocking large numbers of innocent people, e.g. range blocks on
                # schools. Don't blame it on the user. There's a small chance that it
                # really is the user's fault, i.e. the username is blocked and they
                # haven't bothered to log out before trying to create an account to
                # evade it, but we'll leave that to their guilty conscience to figure
                # out.
                $errorParams = array(
                        $block->getTarget(),
                        $block->mReason ? $block->mReason : $this->msg( 'blockednoreason' )->text(),
                        $block->getByName()
                );

                if ( $block->getType() === Block::TYPE_RANGE ) {
                        $errorMessage = 'cantcreateaccount-range-text';
                        $errorParams[] = $this->getRequest()->getIP();
                } else {
                        $errorMessage = 'cantcreateaccount-text';
                }

                throw new ErrorPageError(
                        'cantcreateaccounttitle',
                        $errorMessage,
                        $errorParams
                );
        }

        /**
         * Add a "return to" link or redirect to it.
         * Extensions can use this to reuse the "return to" logic after
         * inject steps (such as redirection) into the login process.
         *
         * @param string $type One of the following:
         *    - error: display a return to link ignoring $wgRedirectOnLogin
         *    - signup: display a return to link using $wgRedirectOnLogin if needed
         *    - success: display a return to link using $wgRedirectOnLogin if needed
         *    - successredirect: send an HTTP redirect using $wgRedirectOnLogin if needed
         * @param string $returnTo
         * @param array|string $returnToQuery
         * @param bool $stickHTTPs Keep redirect link on HTTPs
         * @since 1.22
         */
        public function showReturnToPage(
                $type, $returnTo = '', $returnToQuery = '', $stickHTTPs = false
        ) {
                $this->mReturnTo = $returnTo;
                $this->mReturnToQuery = $returnToQuery;
                $this->mStickHTTPS = $stickHTTPs;
                $this->executeReturnTo( $type );
        }

        /**
         * Add a "return to" link or redirect to it.
         *
         * @param string $type One of the following:
         *    - error: display a return to link ignoring $wgRedirectOnLogin
         *    - signup: display a return to link using $wgRedirectOnLogin if needed
         *    - success: display a return to link using $wgRedirectOnLogin if needed
         *    - successredirect: send an HTTP redirect using $wgRedirectOnLogin if needed
         */
        private function executeReturnTo( $type ) {
                global $wgRedirectOnLogin, $wgSecureLogin;

                if ( $type != 'error' && $wgRedirectOnLogin !== null ) {
                        $returnTo = $wgRedirectOnLogin;
                        $returnToQuery = array();
                } else {
                        $returnTo = $this->mReturnTo;
                        $returnToQuery = wfCgiToArray( $this->mReturnToQuery );
                }

                // Allow modification of redirect behavior
                Hooks::run( 'PostLoginRedirect', array( &$returnTo, &$returnToQuery, &$type ) );

                $returnToTitle = Title::newFromText( $returnTo );
                if ( !$returnToTitle ) {
                        $returnToTitle = Title::newMainPage();
                }

                if ( $wgSecureLogin && !$this->mStickHTTPS ) {
                        $options = array( 'http' );
                        $proto = PROTO_HTTP;
                } elseif ( $wgSecureLogin ) {
                        $options = array( 'https' );
                        $proto = PROTO_HTTPS;
                } else {
                        $options = array();
                        $proto = PROTO_RELATIVE;
                }

                if ( $type == 'successredirect' ) {
                        $redirectUrl = $returnToTitle->getFullURL( $returnToQuery, false, $proto );
                        $this->getOutput()->redirect( $redirectUrl );
                } else {
                        $this->getOutput()->addReturnTo( $returnToTitle, $returnToQuery, null, $options );
                }
        }

        /**
         * @param string $msg
         * @param string $msgtype
         * @throws ErrorPageError
         * @throws Exception
         * @throws FatalError
         * @throws MWException
         * @throws PermissionsError
         * @throws ReadOnlyError
         * @private
         */
        function mainLoginForm( $msg, $msgtype = 'error' ) {
                global $wgEnableEmail, $wgEnableUserEmail;
                global $wgHiddenPrefs, $wgLoginLanguageSelector;
                global $wgAuth, $wgEmailConfirmToEdit;
                global $wgSecureLogin, $wgPasswordResetRoutes;
                global $wgExtendedLoginCookieExpiration, $wgCookieExpiration;

                $titleObj = $this->getPageTitle();
                $user = $this->getUser();
                $out = $this->getOutput();

                if ( $this->mType == 'signup' ) {
                        // Block signup here if in readonly. Keeps user from
                        // going through the process (filling out data, etc)
                        // and being informed later.
                        $permErrors = $titleObj->getUserPermissionsErrors( 'createaccount', $user, true );
                        if ( count( $permErrors ) ) {
                                throw new PermissionsError( 'createaccount', $permErrors );
                        } elseif ( $user->isBlockedFromCreateAccount() ) {
                                $this->userBlockedMessage( $user->isBlockedFromCreateAccount() );

                                return;
                        } elseif ( wfReadOnly() ) {
                                throw new ReadOnlyError;
                        }
                }

                // Pre-fill username (if not creating an account, bug 44775).
                if ( $this->mUsername == '' && $this->mType != 'signup' ) {
                        if ( $user->isLoggedIn() ) {
                                $this->mUsername = $user->getName();
                        } else {
                                $this->mUsername = $this->getRequest()->getSession()->suggestLoginUsername();
                        }
                }

                // Generic styles and scripts for both login and signup form
                $out->addModuleStyles( array(
                        'mediawiki.ui',
                        'mediawiki.ui.button',
                        'mediawiki.ui.checkbox',
                        'mediawiki.ui.input',
                        'mediawiki.special.userlogin.common.styles'
                ) );

                if ( $this->mType == 'signup' ) {
                        // Additional styles and scripts for signup form
                        $out->addModules( array(
                                'mediawiki.special.userlogin.signup.js'
                        ) );
                        $out->addModuleStyles( array(
                                'mediawiki.special.userlogin.signup.styles'
                        ) );

                        $template = new UsercreateTemplate( $this->getConfig() );

                        // Must match number of benefits defined in messages
                        $template->set( 'benefitCount', 3 );

                        $q = 'action=submitlogin&type=signup';
                        $linkq = 'type=login';
                } else {
                        // Additional styles for login form
                        $out->addModuleStyles( array(
                                'mediawiki.special.userlogin.login.styles'
                        ) );

                        $template = new UserloginTemplate( $this->getConfig() );

                        $q = 'action=submitlogin&type=login';
                        $linkq = 'type=signup';
                }

                if ( $this->mReturnTo !== '' ) {
                        $returnto = '&returnto=' . wfUrlencode( $this->mReturnTo );
                        if ( $this->mReturnToQuery !== '' ) {
                                $returnto .= '&returntoquery=' .
                                        wfUrlencode( $this->mReturnToQuery );
                        }
                        $q .= $returnto;
                        $linkq .= $returnto;
                }

                # Don't show a "create account" link if the user can't.
                if ( $this->showCreateOrLoginLink( $user ) ) {
                        # Pass any language selection on to the mode switch link
                        if ( $wgLoginLanguageSelector && $this->mLanguage ) {
                                $linkq .= '&uselang=' . $this->mLanguage;
                        }
                        // Supply URL, login template creates the button.
                        $template->set( 'createOrLoginHref', $titleObj->getLocalURL( $linkq ) );
                } else {
                        $template->set( 'link', '' );
                }

                $resetLink = $this->mType == 'signup'
                        ? null
                        : is_array( $wgPasswordResetRoutes ) && in_array( true, array_values( $wgPasswordResetRoutes ) );

                $template->set( 'header', '' );
                $template->set( 'formheader', '' );
                $template->set( 'skin', $this->getSkin() );
                $template->set( 'name', $this->mUsername );
                $template->set( 'password', $this->mPassword );
                $template->set( 'retype', $this->mRetype );
                $template->set( 'createemailset', $this->mCreateaccountMail );
                $template->set( 'email', $this->mEmail );
                $template->set( 'realname', $this->mRealName );
                $template->set( 'domain', $this->mDomain );
                $template->set( 'reason', $this->mReason );

                $template->set( 'action', $titleObj->getLocalURL( $q ) );
                $template->set( 'message', $msg );
                $template->set( 'messagetype', $msgtype );
                $template->set( 'createemail', $wgEnableEmail && $user->isLoggedIn() );
                $template->set( 'userealname', !in_array( 'realname', $wgHiddenPrefs ) );
                $template->set( 'useemail', $wgEnableEmail );
                $template->set( 'emailrequired', $wgEmailConfirmToEdit );
                $template->set( 'emailothers', $wgEnableUserEmail );
                $template->set( 'canreset', $wgAuth->allowPasswordChange() );
                $template->set( 'resetlink', $resetLink );
                $template->set( 'canremember', $wgExtendedLoginCookieExpiration === null ?
                        ( $wgCookieExpiration > 0 ) :
                        ( $wgExtendedLoginCookieExpiration > 0 ) );
                $template->set( 'usereason', $user->isLoggedIn() );
                $template->set( 'remember', $this->mRemember );
                $template->set( 'cansecurelogin', ( $wgSecureLogin === true ) );
                $template->set( 'stickhttps', (int)$this->mStickHTTPS );
                $template->set( 'loggedin', $user->isLoggedIn() );
                $template->set( 'loggedinuser', $user->getName() );

                if ( $this->mType == 'signup' ) {
                        if ( !self::getCreateaccountToken() ) {
                                self::setCreateaccountToken();
                        }
                        $template->set( 'token', self::getCreateaccountToken() );
                } else {
                        if ( !self::getLoginToken() ) {
                                self::setLoginToken();
                        }
                        $template->set( 'token', self::getLoginToken() );
                }

                # Prepare language selection links as needed
                if ( $wgLoginLanguageSelector ) {
                        $template->set( 'languages', $this->makeLanguageSelector() );
                        if ( $this->mLanguage ) {
                                $template->set( 'uselang', $this->mLanguage );
                        }
                }

                $template->set( 'secureLoginUrl', $this->mSecureLoginUrl );
                // Use signupend-https for HTTPS requests if it's not blank, signupend otherwise
                $usingHTTPS = $this->mRequest->getProtocol() == 'https';
                $signupendHTTPS = $this->msg( 'signupend-https' );
                if ( $usingHTTPS && !$signupendHTTPS->isBlank() ) {
                        $template->set( 'signupend', $signupendHTTPS->parse() );
                } else {
                        $template->set( 'signupend', $this->msg( 'signupend' )->parse() );
                }

                // If using HTTPS coming from HTTP, then the 'fromhttp' parameter must be preserved
                if ( $usingHTTPS ) {
                        $template->set( 'fromhttp', $this->mFromHTTP );
                }

                // Give authentication and captcha plugins a chance to modify the form
                $wgAuth->modifyUITemplate( $template, $this->mType );
                if ( $this->mType == 'signup' ) {
                        Hooks::run( 'UserCreateForm', array( &$template ) );
                } else {
                        Hooks::run( 'UserLoginForm', array( &$template ) );
                }

                $out->disallowUserJs(); // just in case...
                $out->addTemplate( $template );
        }

        /**
         * Whether the login/create account form should display a link to the
         * other form (in addition to whatever the skin provides).
         *
         * @param User $user
         * @return bool
         */
        private function showCreateOrLoginLink( &$user ) {
                if ( $this->mType == 'signup' ) {
                        return true;
                } elseif ( $user->isAllowed( 'createaccount' ) ) {
                        return true;
                } else {
                        return false;
                }
        }

        /**
         * Check if a session cookie is present.
         *
         * This will not pick up a cookie set during _this_ request, but is meant
         * to ensure that the client is returning the cookie which was set on a
         * previous pass through the system.
         *
         * @private
         * @return bool
         */
        function hasSessionCookie() {
                global $wgDisableCookieCheck, $wgInitialSessionId;

                return $wgDisableCookieCheck || (
                        $wgInitialSessionId &&
                        $this->getRequest()->getSession()->getId() === (string)$wgInitialSessionId
                );
        }

        /**
         * Get the login token from the current session
         * @return mixed
         */
        public static function getLoginToken() {
                global $wgRequest;

                return $wgRequest->getSessionData( 'wsLoginToken' );
        }

        /**
         * Randomly generate a new login token and attach it to the current session
         */
        public static function setLoginToken() {
                global $wgRequest;
                // Generate a token directly instead of using $user->getEditToken()
                // because the latter reuses wsEditToken in the session
                $wgRequest->setSessionData( 'wsLoginToken', MWCryptRand::generateHex( 32 ) );
        }

        /**
         * Remove any login token attached to the current session
         */
        public static function clearLoginToken() {
                global $wgRequest;
                $wgRequest->setSessionData( 'wsLoginToken', null );
        }

        /**
         * Get the createaccount token from the current session
         * @return mixed
         */
        public static function getCreateaccountToken() {
                global $wgRequest;
                return $wgRequest->getSessionData( 'wsCreateaccountToken' );
        }

        /**
         * Randomly generate a new createaccount token and attach it to the current session
         */
        public static function setCreateaccountToken() {
                global $wgRequest;
                $wgRequest->setSessionData( 'wsCreateaccountToken', MWCryptRand::generateHex( 32 ) );
        }

        /**
         * Remove any createaccount token attached to the current session
         */
        public static function clearCreateaccountToken() {
                global $wgRequest;
                $wgRequest->setSessionData( 'wsCreateaccountToken', null );
        }

        /**
         * Renew the user's session id, using strong entropy
         */
        private function renewSessionId() {
                global $wgSecureLogin, $wgCookieSecure;
                if ( $wgSecureLogin && !$this->mStickHTTPS ) {
                        $wgCookieSecure = false;
                }

                MediaWiki\Session\SessionManager::getGlobalSession()->resetId();
        }

        /**
         * @param string $type
         * @private
         */
        function cookieRedirectCheck( $type ) {
                $titleObj = SpecialPage::getTitleFor( 'Userlogin' );
                $query = array( 'wpCookieCheck' => $type );
                if ( $this->mReturnTo !== '' ) {
                        $query['returnto'] = $this->mReturnTo;
                        $query['returntoquery'] = $this->mReturnToQuery;
                }
                $check = $titleObj->getFullURL( $query );

                $this->getOutput()->redirect( $check );
        }

        /**
         * @param string $type
         * @private
         */
        function onCookieRedirectCheck( $type ) {
                if ( !$this->hasSessionCookie() ) {
                        if ( $type == 'new' ) {
                                $this->mainLoginForm( $this->msg( 'nocookiesnew' )->parse() );
                        } elseif ( $type == 'login' ) {
                                $this->mainLoginForm( $this->msg( 'nocookieslogin' )->parse() );
                        } else {
                                # shouldn't happen
                                $this->mainLoginForm( $this->msg( 'error' )->text() );
                        }
                } else {
                        $this->successfulLogin();
                }
        }

        /**
         * Produce a bar of links which allow the user to select another language
         * during login/registration but retain "returnto"
         *
         * @return string
         */
        function makeLanguageSelector() {
                $msg = $this->msg( 'loginlanguagelinks' )->inContentLanguage();
                if ( $msg->isBlank() ) {
                        return '';
                }
                $langs = explode( "\n", $msg->text() );
                $links = array();
                foreach ( $langs as $lang ) {
                        $lang = trim( $lang, '* ' );
                        $parts = explode( '|', $lang );
                        if ( count( $parts ) >= 2 ) {
                                $links[] = $this->makeLanguageSelectorLink( $parts[0], trim( $parts[1] ) );
                        }
                }

                return count( $links ) > 0 ? $this->msg( 'loginlanguagelabel' )->rawParams(
                        $this->getLanguage()->pipeList( $links ) )->escaped() : '';
        }

        /**
         * Create a language selector link for a particular language
         * Links back to this page preserving type and returnto
         *
         * @param string $text Link text
         * @param string $lang Language code
         * @return string
         */
        function makeLanguageSelectorLink( $text, $lang ) {
                if ( $this->getLanguage()->getCode() == $lang ) {
                        // no link for currently used language
                        return htmlspecialchars( $text );
                }
                $query = array( 'uselang' => $lang );
                if ( $this->mType == 'signup' ) {
                        $query['type'] = 'signup';
                }
                if ( $this->mReturnTo !== '' ) {
                        $query['returnto'] = $this->mReturnTo;
                        $query['returntoquery'] = $this->mReturnToQuery;
                }

                $attr = array();
                $targetLanguage = Language::factory( $lang );
                $attr['lang'] = $attr['hreflang'] = $targetLanguage->getHtmlCode();

                return Linker::linkKnown(
                        $this->getPageTitle(),
                        htmlspecialchars( $text ),
                        $attr,
                        $query
                );
        }

        protected function getGroupName() {
                return 'login';
        }

        /**
         * Private function to check password expiration, until AuthManager comes
         * along to handle that.
         * @param User $user
         * @return string|bool
         */
        private function checkUserPasswordExpired( User $user ) {
                global $wgPasswordExpireGrace;
                $dbr = wfGetDB( DB_SLAVE );
                $ts = $dbr->selectField( 'user', 'user_password_expires', array( 'user_id' => $user->getId() ) );

                $expired = false;
                $now = wfTimestamp();
                $expUnix = wfTimestamp( TS_UNIX, $ts );
                if ( $ts !== null && $expUnix < $now ) {
                        $expired = ( $expUnix + $wgPasswordExpireGrace < $now ) ? 'hard' : 'soft';
                }
                return $expired;
        }

}