[libmicrohttpd] SSL handshake fails between libcurl and libgnutls/MHD

[Nikos Mavrogiannopoulos]

On 01/23/2012 10:18 PM, Daniel Stenberg wrote:

> On Mon, 23 Jan 2012, Daniel Stenberg wrote:
> 
>> We only had a total of 210 commits in curl between 7.22.0 and 7.23.0
>> so bisecting shouldn't be too time consuming if the procedure to get
>> the bug to appear isn't too slow.
> 
> Ok, so my bisecting identified the attached commit as the offender. If I
> revert this change the libmicrohttpd test seems to run correctly again.
> 
> I would appreciate if someone else helped me verify this.

It doesn't look right. I'd change "-VERS-TLS-ALL:+VERS-SSL3.0" with
"NORMAL:-VERS-TLS-ALL:+VERS-SSL3.0".

However your priority string seem quite radical. You only allow SSL 3.0.
If you care about interoperability I'd suggest a string similar to
http://www.gnu.org/software/gnutls/manual/html_node/Interoperability.html
but even then you have issues like being vulnerable to the "beast" attack.

regards,
Nikos

btw. gnutls 3.0.12 added a check for gnutls_priority_set_direct() to
fail if given a string that adds no actual priorities (like the above).