How to verify gpg files that are encrypted and signed by key thats signed by a CA

[tarithj]

Im using OpenPGP CA tool to manage keys and I use keys generated by it to encrypt and sign messages.
Im trying to verify those messages if they came from a trusted person whos verifies by the CA.

Is this possible? i tried using the CA's PGP public key as the public key in helper.DecryptVerifyMessageArmored() but it fails with a signature error