Method ReceiveResponse

src/network/network_crypto.cpp:285–315

* Read the key exchange data from a \c Packet that came from the client, and check whether the client passes the key * exchange successfully. * @param p The packet that has been received. * @param derived_key_extra_payload The extra payload to pass to the key exchange. * @return Whether the authentication was successful or not. */

 * @return Whether the authentication was successful or not.
 */
NetworkAuthenticationServerHandler::ResponseResult X25519AuthenticationHandler::ReceiveResponse(Packet &p, std::string_view derived_key_extra_payload)
{
	if (p.RemainingBytesToTransfer() != X25519_KEY_SIZE + X25519_MAC_SIZE + X25519_KEY_EXCHANGE_MESSAGE_SIZE) {
		Debug(net, 1, "[crypto] Received auth response of illegal size; authentication aborted.");
		return NetworkAuthenticationServerHandler::ResponseResult::NotAuthenticated;
	}

	X25519KeyExchangeMessage message{};
	X25519Mac mac;

	p.Recv_bytes(this->peer_public_key);
	p.Recv_bytes(mac);
	p.Recv_bytes(message);

	if (!this->derived_keys.Exchange(this->peer_public_key, X25519KeyExchangeSide::SERVER,
			this->our_secret_key, this->our_public_key, derived_key_extra_payload)) {
		Debug(net, 0, "[crypto] Peer sent an illegal public key; authentication aborted.");
		return NetworkAuthenticationServerHandler::ResponseResult::NotAuthenticated;
	}

	if (crypto_aead_unlock(message.data(), mac.data(), this->derived_keys.ClientToServer().data(), this->key_exchange_nonce.data(),
			this->peer_public_key.data(), this->peer_public_key.size(), message.data(), message.size()) != 0) {
		/*
		 * The ciphertext and the message authentication code do not match with the encryption key.
		 * This is most likely an invalid password, or possibly a bug in the client.
		 */
		return NetworkAuthenticationServerHandler::ResponseResult::NotAuthenticated;
	}

	return NetworkAuthenticationServerHandler::ResponseResult::Authenticated;
}


/* virtual */ NetworkAuthenticationClientHandler::RequestResult X25519PAKEClientHandler::ReceiveRequest(struct Packet &p)