I have a task to decrypt a payload from mastercard. So am suppose to use this library
MDESCryptography
I was provided with a keysore password.
and a p12 file.
Please any sample code on how to use that library in c#
Typically, the credit card providers have SDKs for use with theirs services. You need to take the time to read the support documentation that comes with the SDK.
https://developer.mastercard.com/documentation/mdes-customer-service#add-the-sdk-to-your-project