TYPO3 Core

// Make certain that NO user is set initially

$this->user = '';

// Check to see if anyone has submitted login-information and if so register the user with the session. $this->user[uid] may be used to write log...

$this->checkAuthentication();

// Check challenge stored in cookie:

if ($this->challengeStoredInCookie) {

if ($_SESSION['login_challenge'] !== $loginData['chalvalue']) {

if ($this->writeDevLog) {

t3lib_div::devLog('PHP Session stored challenge "' . $_SESSION['login_challenge'] . '" and submitted challenge "' . $loginData['chalvalue'] . '" did not match, so authentication failed!', 't3lib_userAuth', 2);