I'm stuck with the problem. I want to send GPG keys and messages via GET request, but:
- Data block size in the request is limited (4096 symbols), and it is not enough for a typical GPG message, or for a seasoned pubkey;
- Chunks may be sent in the wrong order, or interleaved.
RFC 2440 standard allows chunking armored messages:
BEGIN PGP MESSAGE, PART X/Y Used for multi-part messages, where the armor is split amongst Y parts, and this is the Xth part out of Y. BEGIN PGP MESSAGE, PART X Used for multi-part messages, where this is the Xth part of an unspecified number of parts. Requires the MESSAGE-ID Armor Header to be used.
Unfortunately, I've found no evidence that this feature is implemented in GPG.
But I'd be glad if it was. I could help with that if necessary.