LoginSignupSpecialPage.php

Go to the documentation of this file.

<?php
use MediaWiki\Auth\AuthenticationRequest;
use MediaWiki\Auth\AuthenticationResponse;
use MediaWiki\Auth\AuthManager;
use MediaWiki\Logger\LoggerFactory;
use MediaWiki\MediaWikiServices;
use MediaWiki\Session\SessionManager;
use Wikimedia\ScopedCallback;
 
abstract class LoginSignupSpecialPage extends AuthManagerSpecialPage {
    protected $mReturnTo;
    protected $mPosted;
    protected $mAction;
    protected $mLanguage;
    protected $mReturnToQuery;
    protected $mToken;
    protected $mStickHTTPS;
    protected $mFromHTTP;
    protected $mEntryError = '';
    protected $mEntryErrorType = 'error';
 
    protected $mLoaded = false;
    protected $mLoadedRequest = false;
    protected $mSecureLoginUrl;
    private $reasonValidatorResult = null;
 
    protected $securityLevel;
 
    protected $proxyAccountCreation;
    protected $targetUser;
 
    protected $authForm;
 
    abstract protected function isSignup();
 
    abstract protected function successfulAction( $direct = false, $extraMessages = null );
 
    abstract protected function logAuthResult( $success, $status = null );
 
    public function __construct( $name ) {
        global $wgUseMediaWikiUIEverywhere;
        parent::__construct( $name );
 
        // Override UseMediaWikiEverywhere to true, to force login and create form to use mw ui
        $wgUseMediaWikiUIEverywhere = true;
    }
 
    protected function setRequest( array $data, $wasPosted = null ) {
        parent::setRequest( $data, $wasPosted );
        $this->mLoadedRequest = false;
    }
 
    private function loadRequestParameters() {
        if ( $this->mLoadedRequest ) {
            return;
        }
        $this->mLoadedRequest = true;
        $request = $this->getRequest();
 
        $this->mPosted = $request->wasPosted();
        $this->mAction = $request->getVal( 'action' );
        $this->mFromHTTP = $request->getBool( 'fromhttp', false )
            || $request->getBool( 'wpFromhttp', false );
        $this->mStickHTTPS = $this->getConfig()->get( 'ForceHTTPS' )
            || ( !$this->mFromHTTP && $request->getProtocol() === 'https' )
            || $request->getBool( 'wpForceHttps', false );
        $this->mLanguage = $request->getText( 'uselang' );
        $this->mReturnTo = $request->getVal( 'returnto', '' );
        $this->mReturnToQuery = $request->getVal( 'returntoquery', '' );
    }
 
    protected function load( $subPage ) {
        global $wgSecureLogin;
 
        $this->loadRequestParameters();
        if ( $this->mLoaded ) {
            return;
        }
        $this->mLoaded = true;
        $request = $this->getRequest();
 
        $securityLevel = $this->getRequest()->getText( 'force' );
        if (
            $securityLevel &&
                MediaWikiServices::getInstance()->getAuthManager()->securitySensitiveOperationStatus(
                    $securityLevel ) === AuthManager::SEC_REAUTH
        ) {
            $this->securityLevel = $securityLevel;
        }
 
        $this->loadAuth( $subPage );
 
        $this->mToken = $request->getVal( $this->getTokenName() );
 
        // 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 = $this->getLinkRenderer()->makeKnownLink(
            $this->getPageTitle(),
            $this->msg( 'loginreqlink' )->text(),
            [],
            [
                'returnto' => $this->mReturnTo,
                'returntoquery' => $this->mReturnToQuery,
                'uselang' => $this->mLanguage ?: null,
                'fromhttp' => $wgSecureLogin && $this->mFromHTTP ? '1' : null,
            ]
        );
 
        // Only show valid error or warning messages.
        if ( $entryError->exists()
            && in_array( $entryError->getKey(), LoginHelper::getValidErrorMessages(), true )
        ) {
            $this->mEntryErrorType = 'error';
            $this->mEntryError = $entryError->rawParams( $loginreqlink )->parse();
 
        } elseif ( $entryWarning->exists()
            && in_array( $entryWarning->getKey(), LoginHelper::getValidErrorMessages(), true )
        ) {
            $this->mEntryErrorType = 'warning';
            $this->mEntryError = $entryWarning->rawParams( $loginreqlink )->parse();
        }
 
        # 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 ( T35997 )
        $returnToTitle = Title::newFromText( $this->mReturnTo );
        if ( is_object( $returnToTitle )
            && ( $returnToTitle->isSpecial( 'Userlogout' )
                || $returnToTitle->isSpecial( 'PasswordReset' ) )
        ) {
            $this->mReturnTo = '';
            $this->mReturnToQuery = '';
        }
    }
 
    protected function getPreservedParams( $withToken = false ) {
        global $wgSecureLogin;
 
        $params = parent::getPreservedParams( $withToken );
        $params += [
            'returnto' => $this->mReturnTo ?: null,
            'returntoquery' => $this->mReturnToQuery ?: null,
        ];
        if ( $wgSecureLogin && !$this->isSignup() ) {
            $params['fromhttp'] = $this->mFromHTTP ? '1' : null;
        }
        return $params;
    }
 
    protected function beforeExecute( $subPage ) {
        // finish initializing the class before processing the request - T135924
        $this->loadRequestParameters();
        return parent::beforeExecute( $subPage );
    }
 
    public function execute( $subPage ) {
        if ( $this->mPosted ) {
            $time = microtime( true );
            $profilingScope = new ScopedCallback( function () use ( $time ) {
                $time = microtime( true ) - $time;
                $statsd = MediaWikiServices::getInstance()->getStatsdDataFactory();
                $statsd->timing( "timing.login.ui.{$this->authAction}", $time * 1000 );
            } );
        }
 
        $authManager = MediaWikiServices::getInstance()->getAuthManager();
        $session = SessionManager::getGlobalSession();
 
        // Session data is used for various things in the authentication process, so we must make
        // sure a session cookie or some equivalent mechanism is set.
        $session->persist();
        // Explicitly disable cache to ensure cookie blocks may be set (T152462).
        // (Technically redundant with sessions persisting from this page.)
        $this->getOutput()->enableClientCache( false );
 
        $this->load( $subPage );
        $this->setHeaders();
        $this->checkPermissions();
 
        // Make sure the system configuration allows log in / sign up
        if ( !$this->isSignup() && !$authManager->canAuthenticateNow() ) {
            if ( !$session->canSetUser() ) {
                throw new ErrorPageError( 'cannotloginnow-title', 'cannotloginnow-text', [
                    $session->getProvider()->describe( RequestContext::getMain()->getLanguage() )
                ] );
            }
            throw new ErrorPageError( 'cannotlogin-title', 'cannotlogin-text' );
        } elseif ( $this->isSignup() && !$authManager->canCreateAccounts() ) {
            throw new ErrorPageError( 'cannotcreateaccount-title', 'cannotcreateaccount-text' );
        }
 
        /*
         * 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.
         *
         * Also make an exception when force=<level> is set in the URL, which means the user must
         * reauthenticate for security reasons.
         */
        if ( !$this->isSignup() && !$this->mPosted && !$this->securityLevel &&
             ( $this->mReturnTo !== '' || $this->mReturnToQuery !== '' ) &&
             $this->getUser()->isLoggedIn()
        ) {
            $this->successfulAction();
            return;
        }
 
        // If logging in and not on HTTPS, either redirect to it or offer a link.
        global $wgSecureLogin;
        if ( $this->getRequest()->getProtocol() !== 'https' ) {
            $title = $this->getFullTitle();
            $query = $this->getPreservedParams( false ) + [
                    'title' => null,
                    ( $this->mEntryErrorType === 'error' ? 'error'
                        : 'warning' ) => $this->mEntryError,
                ] + $this->getRequest()->getQueryValues();
            $url = $title->getFullURL( $query, false, PROTO_HTTPS );
            if ( $wgSecureLogin && !$this->mFromHTTP &&
                 wfCanIPUseHTTPS( $this->getRequest()->getIP() )
            ) {
                // 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 ( !$this->isActionAllowed( $this->authAction ) ) {
            // FIXME how do we explain this to the user? can we handle session loss better?
            // messages used: authpage-cannot-login, authpage-cannot-login-continue,
            // authpage-cannot-create, authpage-cannot-create-continue
            $this->mainLoginForm( [], 'authpage-cannot-' . $this->authAction );
            return;
        }
 
        if ( $this->canBypassForm( $button_name ) ) {
            $this->setRequest( [], true );
            $this->getRequest()->setVal( $this->getTokenName(), $this->getToken() );
            if ( $button_name ) {
                $this->getRequest()->setVal( $button_name, true );
            }
        }
 
        $status = $this->trySubmit();
 
        if ( !$status || !$status->isGood() ) {
            $this->mainLoginForm( $this->authRequests, $status ? $status->getMessage() : '', 'error' );
            return;
        }
 
        $response = $status->getValue();
 
        $returnToUrl = $this->getPageTitle( 'return' )
            ->getFullURL( $this->getPreservedParams( true ), false, PROTO_HTTPS );
        switch ( $response->status ) {
            case AuthenticationResponse::PASS:
                $this->logAuthResult( true );
                $this->proxyAccountCreation = $this->isSignup() && !$this->getUser()->isAnon();
                $this->targetUser = User::newFromName( $response->username );
 
                if (
                    !$this->proxyAccountCreation
                    && $response->loginRequest
                    && $authManager->canAuthenticateNow()
                ) {
                    // successful registration; log the user in instantly
                    $response2 = $authManager->beginAuthentication( [ $response->loginRequest ],
                        $returnToUrl );
                    if ( $response2->status !== AuthenticationResponse::PASS ) {
                        LoggerFactory::getInstance( 'login' )
                            ->error( 'Could not log in after account creation' );
                        $this->successfulAction( true, Status::newFatal( 'createacct-loginerror' ) );
                        break;
                    }
                }
 
                if ( !$this->proxyAccountCreation ) {
                    // Ensure that the context user is the same as the session user.
                    $this->setSessionUserForCurrentRequest();
                }
 
                $this->successfulAction( true );
                break;
            case AuthenticationResponse::FAIL:
                // fall through
            case AuthenticationResponse::RESTART:
                unset( $this->authForm );
                if ( $response->status === AuthenticationResponse::FAIL ) {
                    $action = $this->getDefaultAction( $subPage );
                    $messageType = 'error';
                } else {
                    $action = $this->getContinueAction( $this->authAction );
                    $messageType = 'warning';
                }
                $this->logAuthResult( false, $response->message ? $response->message->getKey() : '-' );
                $this->loadAuth( $subPage, $action, true );
                $this->mainLoginForm( $this->authRequests, $response->message, $messageType );
                break;
            case AuthenticationResponse::REDIRECT:
                unset( $this->authForm );
                $this->getOutput()->redirect( $response->redirectTarget );
                break;
            case AuthenticationResponse::UI:
                unset( $this->authForm );
                $this->authAction = $this->isSignup() ? AuthManager::ACTION_CREATE_CONTINUE
                    : AuthManager::ACTION_LOGIN_CONTINUE;
                $this->authRequests = $response->neededRequests;
                $this->mainLoginForm( $response->neededRequests, $response->message, $response->messageType );
                break;
            default:
                throw new LogicException( 'invalid AuthenticationResponse' );
        }
    }
 
    private function canBypassForm( &$button_name ) {
        $button_name = null;
        if ( $this->isContinued() ) {
            return false;
        }
        $fields = AuthenticationRequest::mergeFieldInfo( $this->authRequests );
        foreach ( $fields as $fieldname => $field ) {
            if ( !isset( $field['type'] ) ) {
                return false;
            }
            if ( !empty( $field['skippable'] ) ) {
                continue;
            }
            if ( $field['type'] === 'button' ) {
                if ( $button_name !== null ) {
                    $button_name = null;
                    return false;
                } else {
                    $button_name = $fieldname;
                }
            } elseif ( $field['type'] !== 'null' ) {
                return false;
            }
        }
        return true;
    }
 
    protected function showSuccessPage(
        $type, $title, $msgname, $injected_html, $extraMessages
    ) {
        $out = $this->getOutput();
        $out->setPageTitle( $title );
        if ( $msgname ) {
            $out->addWikiMsg( $msgname, wfEscapeWikiText( $this->getUser()->getName() ) );
        }
        if ( $extraMessages ) {
            $extraMessages = Status::wrap( $extraMessages );
            $out->addWikiTextAsInterface(
                $extraMessages->getWikiText( false, false, $this->getLanguage() )
            );
        }
 
        $out->addHTML( $injected_html );
 
        $helper = new LoginHelper( $this->getContext() );
        $helper->showReturnToPage( $type, $this->mReturnTo, $this->mReturnToQuery, $this->mStickHTTPS );
    }
 
    public function showReturnToPage(
        $type, $returnTo = '', $returnToQuery = '', $stickHTTPS = false
    ) {
        $helper = new LoginHelper( $this->getContext() );
        $helper->showReturnToPage( $type, $returnTo, $returnToQuery, $stickHTTPS );
    }
 
    protected function setSessionUserForCurrentRequest() {
        global $wgUser, $wgLang;
 
        $context = RequestContext::getMain();
        $localContext = $this->getContext();
        if ( $context !== $localContext ) {
            // remove AuthManagerSpecialPage context hack
            $this->setContext( $context );
        }
 
        $user = $context->getRequest()->getSession()->getUser();
 
        $wgUser = $user;
        $context->setUser( $user );
 
        $wgLang = $context->getLanguage();
    }
 
    protected function mainLoginForm( array $requests, $msg = '', $msgtype = 'error' ) {
        $user = $this->getUser();
        $out = $this->getOutput();
 
        // FIXME how to handle empty $requests - restart, or no form, just an error message?
        // no form would be better for no session type errors, restart is better when can* fails.
        if ( !$requests ) {
            $this->authAction = $this->getDefaultAction( $this->subPage );
            $this->authForm = null;
            $requests = MediaWikiServices::getInstance()->getAuthManager()
                ->getAuthenticationRequests( $this->authAction, $user );
        }
 
        // Generic styles and scripts for both login and signup form
        $out->addModuleStyles( [
            'mediawiki.ui',
            'mediawiki.ui.button',
            'mediawiki.ui.checkbox',
            'mediawiki.ui.input',
            'mediawiki.special.userlogin.common.styles'
        ] );
        if ( $this->isSignup() ) {
            // XXX hack pending RL or JS parse() support for complex content messages T27349
            $out->addJsConfigVars( 'wgCreateacctImgcaptchaHelp',
                $this->msg( 'createacct-imgcaptcha-help' )->parse() );
 
            // Additional styles and scripts for signup form
            $out->addModules( 'mediawiki.special.createaccount' );
            $out->addModuleStyles( [
                'mediawiki.special.userlogin.signup.styles'
            ] );
        } else {
            // Additional styles for login form
            $out->addModuleStyles( [
                'mediawiki.special.userlogin.login.styles'
            ] );
        }
        $out->disallowUserJs(); // just in case...
 
        $form = $this->getAuthForm( $requests, $this->authAction, $msg, $msgtype );
        $form->prepareForm();
 
        $submitStatus = Status::newGood();
        if ( $msg && $msgtype === 'warning' ) {
            $submitStatus->warning( $msg );
        } elseif ( $msg && $msgtype === 'error' ) {
            $submitStatus->fatal( $msg );
        }
 
        // warning header for non-standard workflows (e.g. security reauthentication)
        if (
            !$this->isSignup() &&
            $this->getUser()->isLoggedIn() &&
            $this->authAction !== AuthManager::ACTION_LOGIN_CONTINUE
        ) {
            $reauthMessage = $this->securityLevel ? 'userlogin-reauth' : 'userlogin-loggedin';
            $submitStatus->warning( $reauthMessage, $this->getUser()->getName() );
        }
 
        $formHtml = $form->getHTML( $submitStatus );
 
        $out->addHTML( $this->getPageHtml( $formHtml ) );
    }
 
    protected function getPageHtml( $formHtml ) {
        global $wgLoginLanguageSelector;
 
        $loginPrompt = $this->isSignup() ? '' : Html::rawElement( 'div',
            [ 'id' => 'userloginprompt' ], $this->msg( 'loginprompt' )->parseAsBlock() );
        $languageLinks = $wgLoginLanguageSelector ? $this->makeLanguageSelector() : '';
        $signupStartMsg = $this->msg( 'signupstart' );
        $signupStart = ( $this->isSignup() && !$signupStartMsg->isDisabled() )
            ? Html::rawElement( 'div', [ 'id' => 'signupstart' ], $signupStartMsg->parseAsBlock() ) : '';
        if ( $languageLinks ) {
            $languageLinks = Html::rawElement( 'div', [ 'id' => 'languagelinks' ],
                Html::rawElement( 'p', [], $languageLinks )
            );
        }
 
        $benefitsContainer = '';
        if ( $this->isSignup() && $this->showExtraInformation() ) {
            // messages used:
            // createacct-benefit-icon1 createacct-benefit-head1 createacct-benefit-body1
            // createacct-benefit-icon2 createacct-benefit-head2 createacct-benefit-body2
            // createacct-benefit-icon3 createacct-benefit-head3 createacct-benefit-body3
            $benefitCount = 3;
            $benefitList = '';
            for ( $benefitIdx = 1; $benefitIdx <= $benefitCount; $benefitIdx++ ) {
                $headUnescaped = $this->msg( "createacct-benefit-head$benefitIdx" )->text();
                $iconClass = $this->msg( "createacct-benefit-icon$benefitIdx" )->text();
                $benefitList .= Html::rawElement( 'div', [ 'class' => "mw-number-text $iconClass" ],
                    Html::rawElement( 'h3', [],
                        $this->msg( "createacct-benefit-head$benefitIdx" )->escaped()
                    )
                    . Html::rawElement( 'p', [],
                        $this->msg( "createacct-benefit-body$benefitIdx" )->params( $headUnescaped )->escaped()
                    )
                );
            }
            $benefitsContainer = Html::rawElement( 'div', [ 'class' => 'mw-createacct-benefits-container' ],
                Html::rawElement( 'h2', [], $this->msg( 'createacct-benefit-heading' )->escaped() )
                . Html::rawElement( 'div', [ 'class' => 'mw-createacct-benefits-list' ],
                    $benefitList
                )
            );
        }
 
        $html = Html::rawElement( 'div', [ 'class' => 'mw-ui-container' ],
            $loginPrompt
            . $languageLinks
            . $signupStart
            . Html::rawElement( 'div', [ 'id' => 'userloginForm' ],
                $formHtml
            )
            . $benefitsContainer
        );
 
        return $html;
    }
 
    protected function getAuthForm( array $requests, $action, $msg = '', $msgType = 'error' ) {
        // FIXME merge this with parent
 
        if ( isset( $this->authForm ) ) {
            return $this->authForm;
        }
 
        $usingHTTPS = $this->getRequest()->getProtocol() === 'https';
 
        // get basic form description from the auth logic
        $fieldInfo = AuthenticationRequest::mergeFieldInfo( $requests );
        // this will call onAuthChangeFormFields()
        $formDescriptor = $this->fieldInfoToFormDescriptor( $requests, $fieldInfo, $this->authAction );
        $this->postProcessFormDescriptor( $formDescriptor, $requests );
 
        $context = $this->getContext();
        if ( $context->getRequest() !== $this->getRequest() ) {
            // We have overridden the request, need to make sure the form uses that too.
            $context = new DerivativeContext( $this->getContext() );
            $context->setRequest( $this->getRequest() );
        }
        $form = HTMLForm::factory( 'vform', $formDescriptor, $context );
 
        $form->addHiddenField( 'authAction', $this->authAction );
        if ( $this->mLanguage ) {
            $form->addHiddenField( 'uselang', $this->mLanguage );
        }
        $form->addHiddenField( 'force', $this->securityLevel );
        $form->addHiddenField( $this->getTokenName(), $this->getToken()->toString() );
        $config = $this->getConfig();
        if ( $config->get( 'SecureLogin' ) && !$config->get( 'ForceHTTPS' ) ) {
            // If using HTTPS coming from HTTP, then the 'fromhttp' parameter must be preserved
            if ( !$this->isSignup() ) {
                $form->addHiddenField( 'wpForceHttps', (int)$this->mStickHTTPS );
                $form->addHiddenField( 'wpFromhttp', $usingHTTPS );
            }
        }
 
        // set properties of the form itself
        $form->setAction( $this->getPageTitle()->getLocalURL( $this->getReturnToQueryStringFragment() ) );
        $form->setName( 'userlogin' . ( $this->isSignup() ? '2' : '' ) );
        if ( $this->isSignup() ) {
            $form->setId( 'userlogin2' );
        }
 
        $form->suppressDefaultSubmit();
 
        $this->authForm = $form;
 
        return $form;
    }
 
    public function onAuthChangeFormFields(
        array $requests, array $fieldInfo, array &$formDescriptor, $action
    ) {
        $coreFieldDescriptors = $this->getFieldDefinitions();
 
        // keep the ordering from getCoreFieldDescriptors() where there is no explicit weight
        foreach ( $coreFieldDescriptors as $fieldName => $coreField ) {
            $requestField = $formDescriptor[$fieldName] ?? [];
 
            // remove everything that is not in the fieldinfo, is not marked as a supplemental field
            // to something in the fieldinfo, and is not an info field or a submit button
            if (
                !isset( $fieldInfo[$fieldName] )
                && (
                    !isset( $coreField['baseField'] )
                    || !isset( $fieldInfo[$coreField['baseField']] )
                )
                && (
                    !isset( $coreField['type'] )
                    || !in_array( $coreField['type'], [ 'submit', 'info' ], true )
                )
            ) {
                $coreFieldDescriptors[$fieldName] = null;
                continue;
            }
 
            // core message labels should always take priority
            if (
                isset( $coreField['label'] )
                || isset( $coreField['label-message'] )
                || isset( $coreField['label-raw'] )
            ) {
                unset( $requestField['label'], $requestField['label-message'], $coreField['label-raw'] );
            }
 
            $coreFieldDescriptors[$fieldName] += $requestField;
        }
 
        $formDescriptor = array_filter( $coreFieldDescriptors + $formDescriptor );
        return true;
    }
 
    protected function showExtraInformation() {
        return $this->authAction !== $this->getContinueAction( $this->authAction )
            && !$this->securityLevel;
    }
 
    protected function getFieldDefinitions() {
        global $wgEmailConfirmToEdit;
 
        $isLoggedIn = $this->getUser()->isLoggedIn();
        $continuePart = $this->isContinued() ? 'continue-' : '';
        $anotherPart = $isLoggedIn ? 'another-' : '';
        // @phan-suppress-next-line PhanUndeclaredMethod
        $expiration = $this->getRequest()->getSession()->getProvider()->getRememberUserDuration();
        $expirationDays = ceil( $expiration / ( 3600 * 24 ) );
        $secureLoginLink = '';
        if ( $this->mSecureLoginUrl ) {
            $secureLoginLink = Html::element( 'a', [
                'href' => $this->mSecureLoginUrl,
                'class' => 'mw-ui-flush-right mw-secure',
            ], $this->msg( 'userlogin-signwithsecure' )->text() );
        }
        $usernameHelpLink = '';
        if ( !$this->msg( 'createacct-helpusername' )->isDisabled() ) {
            $usernameHelpLink = Html::rawElement( 'span', [
                'class' => 'mw-ui-flush-right',
            ], $this->msg( 'createacct-helpusername' )->parse() );
        }
 
        if ( $this->isSignup() ) {
            $fieldDefinitions = [
                'statusarea' => [
                    // Used by the mediawiki.special.createaccount module for error display.
                    // FIXME: Merge this with HTMLForm's normal status (error) area
                    'type' => 'info',
                    'raw' => true,
                    'default' => Html::element( 'div', [ 'id' => 'mw-createacct-status-area' ] ),
                    'weight' => -105,
                ],
                'username' => [
                    'label-raw' => $this->msg( 'userlogin-yourname' )->escaped() . $usernameHelpLink,
                    'id' => 'wpName2',
                    'placeholder-message' => $isLoggedIn ? 'createacct-another-username-ph'
                        : 'userlogin-yourname-ph',
                ],
                'mailpassword' => [
                    // create account without providing password, a temporary one will be mailed
                    'type' => 'check',
                    'label-message' => 'createaccountmail',
                    'name' => 'wpCreateaccountMail',
                    'id' => 'wpCreateaccountMail',
                ],
                'password' => [
                    'id' => 'wpPassword2',
                    'placeholder-message' => 'createacct-yourpassword-ph',
                    'help-message' => 'createacct-useuniquepass',
                    'hide-if' => [ '===', 'wpCreateaccountMail', '1' ],
                ],
                // used to create empty line to separate help msg
                'pwordbr' => [
                    'cssclass' => 'tipBr',
                    'type' => 'info',
                    'label' => '',
                    'default' => '',
                ],
                'domain' => [],
                'retype' => [
                    'baseField' => 'password',
                    'type' => 'password',
                    'label-message' => 'createacct-yourpasswordagain',
                    'id' => 'wpRetype',
                    'cssclass' => 'loginPassword',
                    'size' => 20,
                    'validation-callback' => function ( $value, $alldata ) {
                        if ( empty( $alldata['mailpassword'] ) && !empty( $alldata['password'] ) ) {
                            if ( !$value ) {
                                return $this->msg( 'htmlform-required' );
                            } elseif ( $value !== $alldata['password'] ) {
                                return $this->msg( 'badretype' );
                            }
                        }
                        return true;
                    },
                    'hide-if' => [ '===', 'wpCreateaccountMail', '1' ],
                    'placeholder-message' => 'createacct-yourpasswordagain-ph',
                ],
                'email' => [
                    'type' => 'email',
                    'label-message' => $wgEmailConfirmToEdit ? 'createacct-emailrequired'
                        : 'createacct-emailoptional',
                    'id' => 'wpEmail',
                    'cssclass' => 'loginText',
                    'size' => '20',
                    // FIXME will break non-standard providers
                    'required' => $wgEmailConfirmToEdit,
                    'validation-callback' => function ( $value, $alldata ) {
                        global $wgEmailConfirmToEdit;
 
                        // AuthManager will check most of these, but that will make the auth
                        // session fail and this won't, so nicer to do it this way
                        if ( !$value && $wgEmailConfirmToEdit ) {
                            // no point in allowing registration without email when email is
                            // required to edit
                            return $this->msg( 'noemailtitle' );
                        } elseif ( !$value && !empty( $alldata['mailpassword'] ) ) {
                            // cannot send password via email when there is no email address
                            return $this->msg( 'noemailcreate' );
                        } elseif ( $value && !Sanitizer::validateEmail( $value ) ) {
                            return $this->msg( 'invalidemailaddress' );
                        }
                        return true;
                    },
                    'placeholder-message' => 'createacct-' . $anotherPart . 'email-ph',
                ],
                'realname' => [
                    'type' => 'text',
                    'help-message' => $isLoggedIn ? 'createacct-another-realname-tip'
                        : 'prefs-help-realname',
                    'label-message' => 'createacct-realname',
                    'cssclass' => 'loginText',
                    'size' => 20,
                    'id' => 'wpRealName',
                ],
                'reason' => [
                    // comment for the user creation log
                    'type' => 'text',
                    'label-message' => 'createacct-reason',
                    'cssclass' => 'loginText',
                    'id' => 'wpReason',
                    'size' => '20',
                    'validation-callback' => function ( $value, $alldata ) {
                        // if the user sets an email address as the user creation reason, confirm that
                        // that was their intent
                        if ( $value && Sanitizer::validateEmail( $value ) ) {
                            if ( $this->reasonValidatorResult !== null ) {
                                return $this->reasonValidatorResult;
                            }
                            $this->reasonValidatorResult = true;
                            $authManager = MediaWikiServices::getInstance()->getAuthManager();
                            if ( !$authManager->getAuthenticationSessionData( 'reason-retry', false ) ) {
                                $authManager->setAuthenticationSessionData( 'reason-retry', true );
                                $this->reasonValidatorResult = $this->msg( 'createacct-reason-confirm' );
                            }
                            return $this->reasonValidatorResult;
                        }
                        return true;
                    },
                    'placeholder-message' => 'createacct-reason-ph',
                ],
                'createaccount' => [
                    // submit button
                    'type' => 'submit',
                    'default' => $this->msg( 'createacct-' . $anotherPart . $continuePart .
                        'submit' )->text(),
                    'name' => 'wpCreateaccount',
                    'id' => 'wpCreateaccount',
                    'weight' => 100,
                ],
            ];
        } else {
            $fieldDefinitions = [
                'username' => [
                    'label-raw' => $this->msg( 'userlogin-yourname' )->escaped() . $secureLoginLink,
                    'id' => 'wpName1',
                    'placeholder-message' => 'userlogin-yourname-ph',
                ],
                'password' => [
                    'id' => 'wpPassword1',
                    'placeholder-message' => 'userlogin-yourpassword-ph',
                ],
                'domain' => [],
                'rememberMe' => [
                    // option for saving the user token to a cookie
                    'type' => 'check',
                    'cssclass' => 'mw-userlogin-rememberme',
                    'name' => 'wpRemember',
                    'label-message' => $this->msg( 'userlogin-remembermypassword' )
                        ->numParams( $expirationDays ),
                    'id' => 'wpRemember',
                ],
                'loginattempt' => [
                    // submit button
                    'type' => 'submit',
                    'default' => $this->msg( 'pt-login-' . $continuePart . 'button' )->text(),
                    'id' => 'wpLoginAttempt',
                    'weight' => 100,
                ],
                'linkcontainer' => [
                    // help link
                    'type' => 'info',
                    'cssclass' => 'mw-form-related-link-container mw-userlogin-help',
                    // 'id' => 'mw-userlogin-help', // FIXME HTMLInfoField ignores this
                    'raw' => true,
                    'default' => Html::element( 'a', [
                        'href' => Skin::makeInternalOrExternalUrl( $this->msg( 'helplogin-url' )
                            ->inContentLanguage()
                            ->text() ),
                    ], $this->msg( 'userlogin-helplink2' )->text() ),
                    'weight' => 200,
                ],
                // button for ResetPasswordSecondaryAuthenticationProvider
                'skipReset' => [
                    'weight' => 110,
                    'flags' => [],
                ],
            ];
        }
 
        $fieldDefinitions['username'] += [
            'type' => 'text',
            'name' => 'wpName',
            'cssclass' => 'loginText',
            'size' => 20,
            // 'required' => true,
        ];
        $fieldDefinitions['password'] += [
            'type' => 'password',
            // 'label-message' => 'userlogin-yourpassword', // would override the changepassword label
            'name' => 'wpPassword',
            'cssclass' => 'loginPassword',
            'size' => 20,
            // 'required' => true,
        ];
 
        if ( $this->mEntryError ) {
            $fieldDefinitions['entryError'] = [
                'type' => 'info',
                'default' => Html::rawElement( 'div', [ 'class' => $this->mEntryErrorType . 'box', ],
                    $this->mEntryError ),
                'raw' => true,
                'rawrow' => true,
                'weight' => -100,
            ];
        }
        if ( !$this->showExtraInformation() ) {
            unset( $fieldDefinitions['linkcontainer'], $fieldDefinitions['signupend'] );
        }
        if ( $this->isSignup() && $this->showExtraInformation() ) {
            // blank signup footer for site customization
            // uses signupend-https for HTTPS requests if it's not blank, signupend otherwise
            $signupendMsg = $this->msg( 'signupend' );
            $signupendHttpsMsg = $this->msg( 'signupend-https' );
            if ( !$signupendMsg->isDisabled() ) {
                $usingHTTPS = $this->getRequest()->getProtocol() === 'https';
                $signupendText = ( $usingHTTPS && !$signupendHttpsMsg->isBlank() )
                    ? $signupendHttpsMsg->parse() : $signupendMsg->parse();
                $fieldDefinitions['signupend'] = [
                    'type' => 'info',
                    'raw' => true,
                    'default' => Html::rawElement( 'div', [ 'id' => 'signupend' ], $signupendText ),
                    'weight' => 225,
                ];
            }
        }
        if ( !$this->isSignup() && $this->showExtraInformation() ) {
            $passwordReset = MediaWikiServices::getInstance()->getPasswordReset();
            if ( $passwordReset->isAllowed( $this->getUser() )->isGood() ) {
                $fieldDefinitions['passwordReset'] = [
                    'type' => 'info',
                    'raw' => true,
                    'cssclass' => 'mw-form-related-link-container',
                    'default' => $this->getLinkRenderer()->makeLink(
                        SpecialPage::getTitleFor( 'PasswordReset' ),
                        $this->msg( 'userlogin-resetpassword-link' )->text()
                    ),
                    'weight' => 230,
                ];
            }
 
            // Don't show a "create account" link if the user can't.
            if ( $this->showCreateAccountLink() ) {
                // link to the other action
                $linkTitle = $this->getTitleFor( $this->isSignup() ? 'Userlogin' : 'CreateAccount' );
                $linkq = $this->getReturnToQueryStringFragment();
                // Pass any language selection on to the mode switch link
                if ( $this->mLanguage ) {
                    $linkq .= '&uselang=' . urlencode( $this->mLanguage );
                }
                $loggedIn = $this->getUser()->isLoggedIn();
 
                $fieldDefinitions['createOrLogin'] = [
                    'type' => 'info',
                    'raw' => true,
                    'linkQuery' => $linkq,
                    'default' => function ( $params ) use ( $loggedIn, $linkTitle ) {
                        return Html::rawElement( 'div',
                            [ 'id' => 'mw-createaccount' . ( !$loggedIn ? '-cta' : '' ),
                                'class' => ( $loggedIn ? 'mw-form-related-link-container' : 'mw-ui-vform-field' ) ],
                            ( $loggedIn ? '' : $this->msg( 'userlogin-noaccount' )->escaped() )
                            . Html::element( 'a',
                                [
                                    'id' => 'mw-createaccount-join' . ( $loggedIn ? '-loggedin' : '' ),
                                    'href' => $linkTitle->getLocalURL( $params['linkQuery'] ),
                                    'class' => ( $loggedIn ? '' : 'mw-ui-button' ),
                                    'tabindex' => 100,
                                ],
                                $this->msg(
                                    $loggedIn ? 'userlogin-createanother' : 'userlogin-joinproject'
                                )->text()
                            )
                        );
                    },
                    'weight' => 235,
                ];
            }
        }
 
        return $fieldDefinitions;
    }
 
    protected function hasSessionCookie() {
        global $wgDisableCookieCheck, $wgInitialSessionId;
 
        return $wgDisableCookieCheck || (
            $wgInitialSessionId &&
            $this->getRequest()->getSession()->getId() === (string)$wgInitialSessionId
        );
    }
 
    protected function getReturnToQueryStringFragment() {
        $returnto = '';
        if ( $this->mReturnTo !== '' ) {
            $returnto = 'returnto=' . wfUrlencode( $this->mReturnTo );
            if ( $this->mReturnToQuery !== '' ) {
                $returnto .= '&returntoquery=' . wfUrlencode( $this->mReturnToQuery );
            }
        }
        return $returnto;
    }
 
    private function showCreateAccountLink() {
        if ( $this->isSignup() ) {
            return true;
        } elseif ( MediaWikiServices::getInstance()
                    ->getPermissionManager()
                    ->userHasRight( $this->getUser(), 'createaccount' )
        ) {
            return true;
        } else {
            return false;
        }
    }
 
    protected function getTokenName() {
        return $this->isSignup() ? 'wpCreateaccountToken' : 'wpLoginToken';
    }
 
    protected function makeLanguageSelector() {
        $msg = $this->msg( 'loginlanguagelinks' )->inContentLanguage();
        if ( $msg->isBlank() ) {
            return '';
        }
        $langs = explode( "\n", $msg->text() );
        $links = [];
        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() : '';
    }
 
    protected function makeLanguageSelectorLink( $text, $lang ) {
        if ( $this->getLanguage()->getCode() == $lang ) {
            // no link for currently used language
            return htmlspecialchars( $text );
        }
        $query = [ 'uselang' => $lang ];
        if ( $this->mReturnTo !== '' ) {
            $query['returnto'] = $this->mReturnTo;
            $query['returntoquery'] = $this->mReturnToQuery;
        }
 
        $attr = [];
        $targetLanguage = MediaWikiServices::getInstance()->getLanguageFactory()
            ->getLanguage( $lang );
        $attr['lang'] = $attr['hreflang'] = $targetLanguage->getHtmlCode();
 
        return $this->getLinkRenderer()->makeKnownLink(
            $this->getPageTitle(),
            $text,
            $attr,
            $query
        );
    }
 
    protected function getGroupName() {
        return 'login';
    }
 
    protected function postProcessFormDescriptor( &$formDescriptor, $requests ) {
        // Pre-fill username (if not creating an account, T46775).
        if (
            isset( $formDescriptor['username'] ) &&
            !isset( $formDescriptor['username']['default'] ) &&
            !$this->isSignup()
        ) {
            $user = $this->getUser();
            if ( $user->isLoggedIn() ) {
                $formDescriptor['username']['default'] = $user->getName();
            } else {
                $formDescriptor['username']['default'] =
                    $this->getRequest()->getSession()->suggestLoginUsername();
            }
        }
 
        // don't show a submit button if there is nothing to submit (i.e. the only form content
        // is other submit buttons, for redirect flows)
        if ( !$this->needsSubmitButton( $requests ) ) {
            unset( $formDescriptor['createaccount'], $formDescriptor['loginattempt'] );
        }
 
        if ( !$this->isSignup() ) {
            // FIXME HACK don't focus on non-empty field
            // maybe there should be an autofocus-if similar to hide-if?
            if (
                isset( $formDescriptor['username'] )
                && empty( $formDescriptor['username']['default'] )
                && !$this->getRequest()->getCheck( 'wpName' )
            ) {
                $formDescriptor['username']['autofocus'] = true;
            } elseif ( isset( $formDescriptor['password'] ) ) {
                $formDescriptor['password']['autofocus'] = true;
            }
        }
 
        $this->addTabIndex( $formDescriptor );
    }
}