eZ\Publish\Core\Repository\UserService::loadUserByCredentials PHP Method

    public function loadUserByCredentials($login, $password)
    {
        if (!is_string($login) || empty($login)) {
            throw new InvalidArgumentValue('login', $login);
        }
        if (!is_string($password)) {
            throw new InvalidArgumentValue('password', $password);
        }
        // Randomize login time to protect against timing attacks
        usleep(mt_rand(0, 30000));
        $spiUser = $this->userHandler->loadByLogin($login);
        $passwordHash = $this->createPasswordHash($login, $password, $this->settings['siteName'], $spiUser->hashAlgorithm);
        if ($spiUser->passwordHash !== $passwordHash) {
            throw new NotFoundException('user', $login);
        }
        return $this->buildDomainUserObject($spiUser);
    }