PayUMoney HashCode is not verifying in Java Spring Boot

Question

I am integrating a payment gateway for the first time. According to PayU's developer guide and the pattern given to create a hashcode. I have a hash sequence as the example below:

String hashSequence =
 "key|txnid|amount|productinfo|firstname|email|udf1|udf2|udf3|udf4|udf5|udf6|udf7|udf8|udf9|udf10";

and raw hashcodeSequence is

sMWHQy46|21|30|REAL ESTATE|Naeem|[email protected]|||||||||||DWsylTyIYs

Now I receive some hash from PayU after a successful transaction and I try to verify it using:

String hashSequence =     
"salt|status|udf10|udf9|udf8|udf7|udf6|udf5|udf4|udf3|udf2|udf1|email|firstname|productinfo|amount|txnid";

and my raw HashSequence for this is:

DWsylTyIYs|success|||||||||||[email protected]|Naeem|REAL ESTATE|30|21|sMWHQy46

But the hash is generating now is not equal to the one recieved from PayU. Why does this happen?

Answer 1

1. Key is missing at the end when you're calculating the hash for the second time.

2. try adding the additionalCharges while you're calculating the hash after the txn is successful :

   String hashSequence =  "additionalCharges|salt|status||||||udf5|udf4|udf3|udf2|udf1|email|firstname|productinfo|amount|txnid|key";