[FFmpeg-devel] [PATCH] lavf/tls_gnutls: retry gnutls_handshake on non fatal errors

[Jan Ekström]

On Wed, Mar 27, 2019 at 2:09 PM Remita Amine <remitamine at gmail.com> wrote:
>
> fixes #7801
>
> Signed-off-by: Remita Amine <remitamine at gmail.com>

This seems to fix switching the cipher suite, and quickly looking at
the gnutls API docs this seems to be the way to do it.

Just tested this with the following as I got a report that opening
Facebook HTTPS URLs didn't work in a libavformat API client:
1. youtube-dl -g "https://www.facebook.com/downshiftaus/videos/418766325569703/"
   (you receive a URL)
2. ffprobe 'THAT_URL'

Without this patch the handshake fails (as there is a cipher
re-negotiation?), and with the patch it works.

Additionally, this doesn't seem to enable bad TLS configurations such
https://rc4.badssl.com/ to get opened. Which is expected from the
gnutls docs, but still I felt like testing.

In other words, I think this is LGTM and since there already are
reports from people on distros running into this, this should be
back-ported to the versions still maintained by us (whatever those
are) ?

Best regards,
Jan