Feature: #59231 - Hook for AbstractUserAuthentication::checkAuthentication() 

Description 

Hook to post-process login failures in AbstractUserAuthentication::checkAuthentication. By default the process sleeps for five seconds in case of failing. By using this hook, different solutions for brute force protection can be implemented.

Register like this:

$GLOBALS['TYPO3_CONF_VARS']['SC_OPTIONS']['t3lib/class.t3lib_userauth.php']['postLoginFailureProcessing'][] = 'My\\Package\\HookClass->hookMethod';