3. Callback To Merchant Portal

CallBack/ Response URL

<YourCallBackURL>?trackid=xxxx&result=xxxx&refid=&errormessage=&Hash=xxxx

Call Back Response Parameters

Parameters	Data Type	Description
trackid	string	Reference ID passed in the request.
result	string	Payment result. Example: CAPTURED, NOT CAPTURED, DECLINED, REJECTED, BLOCKED.
refid	string	Payment Reference Number.
error message	string	If result is other than CAPTURED, then it gives you the actual reason.
hash	string	Use this for integrity of the data explained in response integrity section

How to identify parameters that are tampered?

If you want to check whether the parameters tamper or not, convert below parameters into a hash and compare with your hash which you got as a response in a query string.

Use the below method to identify parameter tempering.

  String outParams = $"trackid={trackid}&result={result}&refid={refid}";
  String outhashValue = GetHashValue(outParams,_key);
  if (Hash != outhashValue)
  {
  //This means it is tampered
  // Your code
  }
  else{
  }