Don't try to continue Handshake if timeout expired.

td/mtproto/Handshake.cpp

@@ -47,12 +47,20 @@ static Result<typename T::ReturnType> fetch_result(Slice message, bool check_end
 }
 
 AuthKeyHandshake::AuthKeyHandshake(int32 dc_id, int32 expires_in)
-    : mode_(expires_in == 0 ? Mode::Main : Mode::Temp), dc_id_(dc_id), expires_in_(expires_in) {
+    : mode_(expires_in == 0 ? Mode::Main : Mode::Temp)
+    , dc_id_(dc_id)
+    , expires_in_(expires_in)
+    , timeout_at_(Time::now() + 1e9) {
+}
+
+void AuthKeyHandshake::set_timeout_in(double timeout_in) {
+  timeout_at_ = Time::now() + timeout_in;
 }
 
 void AuthKeyHandshake::clear() {
   last_query_ = BufferSlice();
   state_ = Start;
+  timeout_at_ = Time::now() + 1e9;
 }
 
 bool AuthKeyHandshake::is_ready_for_finish() const {
@@ -294,6 +302,10 @@ Status AuthKeyHandshake::on_start(Callback *connection) {
 
 Status AuthKeyHandshake::on_message(Slice message, Callback *connection, AuthKeyHandshakeContext *context) {
   Status status = [&] {
+    if (Time::now() >= timeout_at_) {
+      return Status::Error("Handshake timeout expired");
+    }
+
     switch (state_) {
       case ResPQ:
         return on_res_pq(message, connection, context->get_public_rsa_key_interface());

td/mtproto/Handshake.h

@@ -45,6 +45,8 @@ class AuthKeyHandshake {
 
   AuthKeyHandshake(int32 dc_id, int32 expires_in);
 
+  void set_timeout_in(double timeout_in);
+
   bool is_ready_for_finish() const;
 
   void on_finish();
@@ -80,6 +82,8 @@ class AuthKeyHandshake {
   int32 expires_in_ = 0;
   double expires_at_ = 0;
 
+  double timeout_at_ = 0;
+
   AuthKey auth_key_;
   double server_time_diff_ = 0;
   uint64 server_salt_ = 0;

td/mtproto/HandshakeActor.cpp

@@ -34,6 +34,7 @@ void HandshakeActor::close() {
 void HandshakeActor::start_up() {
   Scheduler::subscribe(connection_->get_poll_info().extract_pollable_fd(this));
   set_timeout_in(timeout_);
+  handshake_->set_timeout_in(timeout_);
   yield();
 }