Re: [Evolution-hackers] evolution failing on TLSv1.3 after gnutls upgrade

[James Bottomley <James Bottomley HansenPartnership com>]

On Fri, 2019-05-10 at 23:23 +0200, Sasa Ostrouska via evolution-hackers 
wrote:
> Hi all, and thanks Milan for the program. I also run an old version
> of evolution 3.20.x and I get the following:
>
> rc@rc-laptop:~/Downloads$ gcc `pkg-config --cflags --libs glib-2.0
> gio-2.0` imap-conn.c -g -O0 -o imap-conn && ./imap-conn
> imap.googlemail.com 993
> Connected to imap.googlemail.com:993
> Failed to read data from the server: Error reading data from TLS
> socket: The specified session has been invalidated for some reason.
>
> I neded to #include <string.h> on my slackware linux.

Me too, but it was a trivial update.

I did a bit of build bisection.  Most of the failing glib-networking
packages are 2.54.1 and below.  2.55.2 is the first working version
(2.55.1 doesn't build due to missing glib-pacrunner).  So, clearly,
whatever the TLSv1.3 bug was it was fixed in this version, but I can
find neither a bugzilla nor a commit obviously identifying the problem.

2.54.1 was the last version that used autoconf, 2.55.2 uses meson,
which probably explains why a few distributions are stuck on 2.54.1.

I think the solution is to simply bar glib-networking below 2.55.2 from
using gnutls VERS-TLS1.3 which looks like it can be done reasonably
well in g_tls_connection_gnutls_init_priorities()

James