Any way to specify the SSL/TLS protocol version in OpenConnect?

Nikos Mavrogiannopoulos n.mavrogiannopoulos at
Tue Sep 19 01:26:40 PDT 2017

On Mon, Sep 18, 2017 at 1:24 AM, Miguel Cruz <miguel.cruz at> wrote:
> Hi,
> I'm trying to connect to some Cisco Anyconnect server I do not control
> but the connection apparently fails during the SSL negotiation.
> I have investigated the issue using openssl and found that the server
> only supports TSLv1 with protocol renegotiation disabled.
> Is there any way to specify OpenConnect which SSL/TLS protocol to use?

Only if you compile openconnect with the
'--with-default-gnutls-priority' option, and then set a priority which
only enables TLS1.0. You may want to try tools like gnutls-cli-debug
to see whether there can be something done with that server.


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