How can I decrypt sub message with gpgme?

Question

Is there a possibility to decrypt one message, where you decrypt first sub-message and then second....

for example if your message is really large, and you don't want keep whole message in memory!?

Can't find anything in manual, or in google!

Answer 1

The short answer is no. This is theoretically possible, but GPGme doesn’t support it.

OpenPGP (and therefore GPG) uses CFB (cipher feedback) mode to encrypt message data, which means to decrypt any part of the message, one must decrypt all the ciphertext before it. So, like I said, it’s theoretically possible to halt the decryption process halfway through the message, process the part decrypted so far, and then proceed; however, GPGme doesn’t support this operation. GPGme is really designed to be a toolkit of the most common GPG-related operations so that users don’t have to work with the lower-level libgcrypt.