gnutls-cgi (version 2.8.1) on ubuntu 8.04 crashes

[Simon Josefsson]

Sunil P Khatri <sunilkhatri at tamu.edu> writes:

> Folks,
>
> I am running Ubuntu 8.04 on a i386. While setting up the 
> claws-mail client to use IMAP, I systematically got stream
> errors and a failure to connect to the IMAP server.
>
> The fine folks at the claws-mail support team diagnosed 
> this as a gnutls bug. I am using 2.8.1, compiled out of the
> source tarball. 
>
> Below is a trace to illustrate the problem. The problem 
> does not occur if I use SSL.

Hi!  Thanks for the report.

> * OK IMAP4 ready
> 1 CAPABILITY  
> *** Fatal error: A TLS packet with unexpected length was received.
> *** Server has terminated the connection abnormally.

The server does not appear to support record padding, which is a known
problem with some servers, see:

http://www.gnu.org/software/gnutls/manual/html_node/On-Record-Padding.html

You can work around the problem by using the %COMPAT priority string:

gnutls-cli neo.tamu.edu --port 993 -d 4711 --priority NORMAL:%COMPAT

Claws mail should have a configuration knob that allows users to supply
a GnuTLS priority string.  The configuration string should be preferably
be per-server.  Would you bounce back that suggestion to them?  The
graphical interface could also use a knob to disable record padding
directly, without having the user understand GnuTLS priority strings.
Then claws mail needs to convert the knob settings to a priority string
internally.

Thanks,
Simon