Nikos Mavrogiannopoulos nmav@gnutls.org writes:
I think having a limitation that q_size < p_size/2 is pretty much reasonable. The recommendations for DH parameters have q_size << p_size/2.
Good to know. I was thinking that, e.g., p_size = q_size + 1 (and p = 2q + 1) was important. But maybe that's a special case, and the general case of q_size close to p_size is not very important?
I don't think it makes much sense to keep the old function if the ABI breaks anyway. It's not that big deal of a change, but it's up to you.
My concerns here are mainly with source-level API (since we already know there will be an ABI break). It helps applications to transition to the new version if it's reasonably easy to write code which works with both the new and the old version. So they can do minimal changes to be able to compile with either version, and later move over to use the new API.
Regards, /Niels