[openssl-dev] How to get SSL version from SSL_SESSION using OpenSSL-1.1.x?

[TJ Saunders]

> > I'm currently working on updating proftpd and its various modules to
> > work with the changed APIs in OpenSSL-1.1.x.  My current obstacle(?) is
> > to determine the SSL protocol version, given an SSL_SESSION pointer.
> > 
> > Using OpenSSL-1.0.x, I currently use:
> > 
> >   ssl_version = sess->ssl_version;
> > 
> > However, I don't see an equivalent accessor in the 1.1.x APIs.  Have I
> > missed something, or does such a thing not exist yet?
> 
> I don't think such a thing exists at the moment. Out of interest why do
> you need it?

One of the modules maintains the server-side SSL session cache,
comprised of SSL_SESSION objects.  For debugging purposes, there's a
tool to dump out the sessions in the cache.  I had initially used
SSL_SESSION_print() for this dump utility, but that prints out more of
the session data (e.g. the master key) than I'd wanted.  Thus I ended up
writing my own code for printing out the fields of the SSL_SESSION which
I thought would be of interest -- including the protocol version of the
SSL_SESSION.

Cheers,
TJ