Change crypto code

I work on a project or test a new encryption algorithm, and tester on a LORA application, I installed everything and all works well, now I have to understand the function of files “go”, I saw that script “go” used cryptography library! could i know what is the go script that decrypts the playload in the app server, can you tell me which are the script that load this decryption of the playload, thanks.