[TASK] Streamline frontend user password recovery process

The ext:felogin recovery process is using a non-typesafe comparison which might be exploited with a probability of 0.000000294% and is storing the recovery token as plain MD5-hash in database. In order to streamline the process non-typesafe comparison is using PHP's hash_equals() method; for keeping backward compatibility just HMAC-SHA1 is applied to the recovery token in database. Since exploitations to this scenario are very unlikely (for a 50% chance an attacker would have to trigger the creation of around 170 million recovery requests) it is not handled with a security workflow - but using the public workflow. Resolves: #89952 Releases: master, 10.2, 9.5, 8.7 Change-Id: Idcb7b7d6eb418124dc17f1707284b6abe8a8b63b Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/62693 Tested-by: Oliver Hader <oliver.hader@typo3.org> Reviewed-by: Oliver Hader <oliver.hader@typo3.org>
TYPO3 · Dec 17, 2019 · d075cde · d075cde
1 parent 6ea5b19
commit d075cde
Showing 1 changed file with 8 additions and 2 deletions.
diff --git a/typo3/sysext/felogin/Classes/Controller/FrontendLoginController.php b/typo3/sysext/felogin/Classes/Controller/FrontendLoginController.php
@@ -340,7 +340,13 @@ protected function changePassword()
             $user = $this->pi_getRecord('fe_users', (int)$uid);
             $userHash = $user['felogin_forgotHash'];
             $compareHash = explode('|', $userHash);
-            if (!$compareHash || !$compareHash[1] || $compareHash[0] < time() || $hash[0] != $compareHash[0] || md5($hash[1]) != $compareHash[1]) {
+            if (strlen($compareHash[1]) === 40) {
+                $hashEquals = hash_equals($compareHash[1], GeneralUtility::hmac((string)$hash[1]));
+            } else {
+                // backward-compatibility for previous MD5 hashes
+                $hashEquals = hash_equals($compareHash[1], md5($hash[1]));
+            }
+            if (!$compareHash || !$compareHash[1] || $compareHash[0] < time() || !hash_equals($compareHash[0], $hash[0]) || !$hashEquals) {
                 $markerArray['###STATUS_MESSAGE###'] = $this->getDisplayText(
                     'change_password_notvalid_message',
                     $this->conf['changePasswordNotValidMessage_stdWrap.']
@@ -459,7 +465,7 @@ protected function generateAndSendHash($user)
         $validEndString = date($this->conf['dateFormat'], $validEnd);
         $hash = md5(GeneralUtility::makeInstance(Random::class)->generateRandomBytes(64));
         $randHash = $validEnd . '|' . $hash;
-        $randHashDB = $validEnd . '|' . md5($hash);
+        $randHashDB = $validEnd . '|' . GeneralUtility::hmac($hash);
 
         // Write hash to DB
         $userTable = $this->frontendController->fe_user->user_table;