Verify deb package using OpenSSL C++

[seeker123]

Hi, I am trying to verify a deb package using OpenSSL C++. The signature was generated using the following Command:

openssl dgst -sign privatekey.pem -keyform PEM -sha256 -out signaturefile.sign -binary package.deb

I am receiving signature in base64 encoding. Can please someone show me how to do it. Also how to convert base64 encoding to appropriate encoding. Thanks in advance

[SwissProgrammer]

Would you please give a lot more information, without giving away any secrets or security?