'Uses GSSAPI to authenticate the server'

def authenticate_server(self, r):

    log.debug(('authenticate_server():    Authenticate    header:    %s' % _negotiate_value(r)))
    result = k.authGSSClientStep(self.context, _negotiate_value(r))
    if (result < 1):
        raise Exception('authGSSClientStep    failed')
    _r = r.request.response
    log.debug(('authenticate_server():    returning    %s' % _r))
    return _r
