Baikal: Authentication bypass

The file PDOBasicAuth is vulnerable to an authentication bypass in the validateUserPass function:

    function validateUserPass($username, $password) {

        $stmt = $this->pdo->prepare('SELECT username, digesta1 FROM ' . $this->tableName . ' WHERE username = ?');
        $stmt->execute([$username]);
        $result = $stmt->fetchAll();


        if (!count($result)) return false;

        $hash = md5($username . ':' . $this->authRealm . ':' . $password);
        if ($result[0]['digesta1'] == $hash)
        {
            $this->currentUser = $username;
            return true;
        }
        return false;

    }

Using the == operator make the authentication test vulnerable to type juggling: if the expected hash ($result[0]['digesta1']) starts with0e, it will match against any hash that also starts with0e`.

A way to fix this would be to use the === operator instead.