def _authenticate_and_send_msg(self, username, chat_msg):
# start peer authentication
nonce = util.get_good_nonce(self.request_cache)
new_auth = ClientClientAuthentication(username, self.auth.crypto_service, chat_msg)
new_auth.timestamp = PacketOrganiser.get_new_timestamp() # timestamp when created, for packet resend
key = self.auth.dh_key
msg_to_send = PacketOrganiser.prepare_packet([c.MSG_TYPE_START_NEW_CHAT, username, ""], nonce=nonce)
util.add_to_request_cache(
self.request_cache, nonce, c.MSG_TYPE_START_NEW_CHAT, key, msg_to_send, self.auth.server_addr, new_auth
) # add to cache
return username, self.auth.server_addr, self.serv.sym_encrypt(key, msg_to_send)
