Re: Interop lsh and SSH-2.0-GitLab-SSHD

Peter Gutmann <[email protected]> Sun, 29 Oct 2023 04:41:56 +0000

Newsgroups	gmane.ietf.secsh
Message-ID	<SY4PR01MB6251796D94BB0CCF9ADFF839EEA2A@SY4PR01MB6251.ausprd01.prod.outlook.com>

Mouse <[email protected]> writes:

>So it's not just modulus size, but I'm wondering if the gitlab code is stupid
>enough to consider any exponent over 65537 as an error or some such.

My guess is it considers any exponent larger than a machine word (which makes
ops with it quite efficient) as irrational and therefore rejects it.  My code
does this too - there's no sane reason for having an exponent like that apart
from opening yourself up to DoS attacks.

Peter.