Ajout test si le login usurpé existe bien dans l'annuaire.

src/UnicaenAuth/Authentication/Adapter/Ldap.php

@@ -84,6 +84,13 @@ class Ldap extends AbstractAdapter implements ServiceManagerAwareInterface, Even
         $result = $this->getLdapAuthAdapter()->setUsername($username)->setPassword($credential)->authenticate();
         $failure = !$result->isValid();
         
+        // verif existence du login usurpé
+        if ($usernameUsurpe) {
+            if (!$this->getLdapAuthAdapter()->getLdap()->searchEntries("(supannAliasLogin=$usernameUsurpe)")) {
+                $usernameUsurpe = null;
+            }
+        }
+        
         // Failure!
         if ($failure) {
             $e->setCode(AuthenticationResult::FAILURE)