DAVE user join/part (#1276)

include/dpp/discordvoiceclient.h

@@ -166,7 +166,7 @@ enum voice_websocket_opcode_t : uint8_t {
 	voice_client_dave_mls_key_package = 26,
 	voice_client_dave_mls_proposals = 27,
 	voice_client_dave_mls_commit_message = 28,
-	voice_client_dave_announce_commit_transaction = 29,
+	voice_client_dave_announce_commit_transition = 29,
 	voice_client_dave_mls_welcome = 30,
 	voice_client_dave_mls_invalid_commit_welcome = 31,
 };
@@ -206,7 +206,7 @@ struct dave_binary_header_t {
 	[[nodiscard]] std::vector<uint8_t> get_data() const;
 
 	/**
-	 * Get transition ID for process_welcome
+	 * Get transition ID for process_commit and process_welcome
 	 *
 	 * @return Transition ID
 	 */
@@ -215,7 +215,7 @@ struct dave_binary_header_t {
 private:
 	/**
 	 * @brief Transition id, only valid when the opcode is
-	 * welcome state. Use get_transition_id() to obtain value.
+	 * commit and welcome state. Use get_transition_id() to obtain value.
 	 */
 	uint16_t transition_id;
 };
@@ -478,11 +478,12 @@ class DPP_EXPORT discord_voice_client : public websocket_client
 	std::set<std::string> dave_mls_user_list;
 
 	/**
-	 * @brief The list of users that just joined for DAVE
+	 * @brief The list of users that have left the voice channel but
+	 * not yet removed from MLS group.
 	 */
-	std::set<std::string> dave_mls_new_user_list;
+	std::set<std::string> dave_mls_pending_remove_list;
 
-		/**
+	/**
 	 * @brief File descriptor for UDP connection
 	 */
 	dpp::socket fd;
@@ -1200,6 +1201,39 @@ class DPP_EXPORT discord_voice_client : public websocket_client
 	 * which internally uses scrypt.
 	 */
 	void get_user_privacy_code(const dpp::snowflake user, privacy_code_callback_t callback) const;
+
+	/**
+	 * @brief Notify gateway ready for a DAVE transition.
+	 *
+	 * Fires Voice Ready event when appropriate.
+	 *
+	 * https://daveprotocol.com/#commit-handling
+	 */
+	void ready_for_transition(const std::string &data);
+
+	/**
+	 * @brief Reset dave session, send voice_client_dave_mls_invalid_commit_welcome
+	 * payload with current transition Id and our new key package to gateway.
+	 *
+	 * https://daveprotocol.com/#recovery-from-invalid-commit-or-welcome
+	 */
+	void recover_from_invalid_commit_welcome();
+
+	/**
+	 * @brief Execute pending protocol upgrade/downgrade to/from dave.
+	 * @return true if did an upgrade/downgrade
+	 */
+	bool execute_pending_upgrade_downgrade();
+
+	/**
+	 * @brief Reset dave session and prepare initial session group.
+	 */
+	void reinit_dave_mls_group();
+
+	/**
+	 * @brief Process roster map from commit/welcome.
+	 */
+	void process_mls_group_rosters(const std::map<unsigned long, std::vector<unsigned char>> &rmap);
 };
 
 } // namespace dpp

src/dpp/discordvoiceclient.cpp

@@ -85,8 +85,9 @@ bool discord_voice_client::is_playing() {
 }
 
 uint16_t dave_binary_header_t::get_transition_id() const {
-	if (opcode != voice_client_dave_mls_welcome) {
-		throw dpp::logic_exception("Can't get transition ID from buffer that is not of type voice_client_dave_mls_welcome(30)");
+	bool has_transition_id = opcode == voice_client_dave_mls_welcome || opcode == voice_client_dave_announce_commit_transition;
+	if (!has_transition_id) {
+		throw dpp::logic_exception("Can't get transition ID from buffer that is not of type voice_client_dave_announce_commit_transition(29) or voice_client_dave_mls_welcome(30)");
 	}
 	return transition_id;
 }
@@ -98,7 +99,9 @@ dave_binary_header_t::dave_binary_header_t(const std::string& buffer) {
 	seq = (buffer[0] << 8) | buffer[1];
 	opcode = buffer[2];
 	transition_id = (buffer[3] << 8) | buffer[4];
-	package.assign(buffer.begin() + (opcode == voice_client_dave_mls_welcome ? 5 : 3), buffer.end());
+
+	bool has_transition_id = opcode == voice_client_dave_mls_welcome || opcode == voice_client_dave_announce_commit_transition;
+	package.assign(buffer.begin() + (has_transition_id ? 5 : 3), buffer.end());
 }
 
 std::vector<uint8_t> dave_binary_header_t::get_data() const {
@@ -129,13 +132,17 @@ void discord_voice_client::get_user_privacy_code(const dpp::snowflake user, priv
 
 bool discord_voice_client::is_end_to_end_encrypted() const {
 #ifdef HAVE_VOICE
-	if (mls_state == nullptr) {
+	if (mls_state == nullptr || mls_state->encryptor == nullptr) {
 		return false;
 	}
 
 	bool has_pending_downgrade = mls_state->pending_transition.is_pending && mls_state->pending_transition.protocol_version != dave_version_1;
 
-	return !has_pending_downgrade && !mls_state->privacy_code.empty();
+	/* 
+	 * A dave_version 0 should be enough to know we're in non-e2ee session, we should also check for pending downgrade and
+	 * whether session encryptor actually has key rachet set to encrypt opus packets.
+	 */
+	return !has_pending_downgrade && dave_version != dave_version_none && mls_state->encryptor->has_key_ratchet();
 #else
 	return false;
 #endif

src/dpp/voice/enabled/enabled.h

@@ -87,18 +87,10 @@ struct dave_state {
 	 * @brief Our key package
 	 */
 	std::shared_ptr<::mlspp::SignaturePrivateKey> mls_key;
-	/**
-	 * @brief Cached commit package for use in welcome
-	 */
-	std::vector<uint8_t> cached_commit;
 	/**
 	 * @brief Current transition ID
 	 */
 	uint64_t transition_id{0};
-	/**
-	 * @brief True when we have a sending ratchet
-	 */
-	bool have_sending_ratchet{false};
 	/**
 	 * @brief Have sent ready event to listeners
 	 */
@@ -133,6 +125,11 @@ struct dave_state {
 	 * MLS group is not established.
 	 */
 	std::string privacy_code;
+
+	/**
+	 * @brief Cached roster map to track rosters changes.
+	 */
+	dave::roster_map cached_roster_map;
 };
 
 /**