[gnutls-devel] [resent][PATCH] ALPN and session resumption

Nikos Mavrogiannopoulos nmav at gnutls.org
Fri Mar 18 11:17:43 CET 2016

On Fri, Mar 18, 2016 at 10:53 AM, Yuriy M. Kaminskiy <yumkam at gmail.com> wrote:
>>> I played with gdb, looked at gnutls sources, and found that libgnutls
>>> neither parse ALPN extension on resume[1], nor re-uses session data[2],
>>> as a
>>> result after session resumption gnutls_alpn_get_selected_protocol()
>>> returns
>>> failure (even though server sent ALPN/h2 in ServerHello).
>>> I've re-tested with (self-compiled) gnutls 3.3.22, it behaves same.
>>> I cannot test with 3.4.* atm (missing build-req), but quick look at
>>> sources
>>> suggests bug is still present.
>> Thank you for reporting that. It may make sense to move the ALPN
>> extension to the mandatory to parse set. I'll check it, and try to
>> introduce some checks to detect this issue.
> I considered changing it at first, but it would interfere with sever-side
> (GNUTLS_EXT_APPLICATION are parsed *before* running user-defined hook,
> *MANDATORY - after).

Right. That's also desirable. In master the mandatory extensions are
parsed first so
that wouldn't require any change but for 3.3 and 3.4 I'd need to
change that as well
and introduce a check.


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