CAllUser::LoginByDigest

public function LoginByDigest($arDigest)
{
	//array("username"=>"", "nonce"=>"", "uri"=>"", "response"=>"")
	/** @global CMain $APPLICATION */
	global $DB, $APPLICATION;

	$APPLICATION->ResetException();

	$strSql =
		"SELECT U.ID, U.PASSWORD, UD.DIGEST_HA1, U.EXTERNAL_AUTH_ID " .
		"FROM b_user U LEFT JOIN b_user_digest UD ON UD.USER_ID=U.ID " .
		"WHERE U.LOGIN='" . $DB->ForSQL($arDigest["username"]) . "' ";
	$res = $DB->Query($strSql);

	if ($arUser = $res->Fetch())
	{
		$method = ($_SERVER['REDIRECT_REQUEST_METHOD'] ?? $_SERVER['REQUEST_METHOD']);
		$HA2 = md5($method . ':' . $arDigest['uri']);

		if ($arUser["EXTERNAL_AUTH_ID"] == '' && $arUser["DIGEST_HA1"] != '')
		{
			//digest is for internal authentication only
			static::$kernelSession["BX_HTTP_DIGEST_ABSENT"] = false;

			$HA1 = $arUser["DIGEST_HA1"];
			$valid_response = md5($HA1 . ':' . $arDigest['nonce'] . ':' . $HA2);

			if ($arDigest["response"] === $valid_response)
			{
				//regular user password
				return $this->Login($arDigest["username"], $arUser["PASSWORD"], 'N', 'N');
			}
		}

		//check for an application password, including external users
		if (($appPassword = ApplicationPasswordTable::findDigestPassword($arUser["ID"], $arDigest)) !== false)
		{
			return $this->Login($arDigest["username"], $appPassword["PASSWORD"], 'N', 'N');
		}

		if ($arUser["DIGEST_HA1"] == '')
		{
			//this indicates that we still have no user digest hash
			static::$kernelSession["BX_HTTP_DIGEST_ABSENT"] = true;
		}
	}

	$APPLICATION->ThrowException(GetMessage("USER_AUTH_DIGEST_ERR"));
	return ["MESSAGE" => GetMessage("USER_AUTH_DIGEST_ERR") . "
", "TYPE" => "ERROR"];
}