certutils.get_host_cert does not work behind proxy

[xsun12]

Another place where recording https archives through proxy is not working yet.

I have a patch that uses httpclient.get_connection (made public) to get a connection and use that connection to retrieve server certificate. This resolves the proxy issue because get_connection() is proxy aware.

cert = connection.sock.getpeercert(True)
cert = ssl.DER_cert_to_PEM_cert(cert)

What do you think?