Merge branch 'fredrik/ssh/better-error-messages/OTP-10553'

* fredrik/ssh/better-error-messages/OTP-10553:
  Added event/3 and clarified error message
  Error msg to be returned together with Key exchange failed
  Returning the actual reason why key exchange failed

3 files changed, 56 insertions, 10 deletions

diff --git a/lib/ssh/src/ssh_connection_handler.erl b/lib/ssh/src/ssh_connection_handler.erl
index 787d82c4db..74a6ac7d19 100644
--- a/lib/ssh/src/ssh_connection_handler.erl
+++ b/lib/ssh/src/ssh_connection_handler.erl
@@ -223,11 +223,13 @@ key_exchange(#ssh_msg_kexdh_reply{} = Msg,
     catch
 	#ssh_msg_disconnect{} = DisconnectMsg ->
 	    handle_disconnect(DisconnectMsg, State);
+	{ErrorToDisplay, #ssh_msg_disconnect{} = DisconnectMsg} ->
+	    handle_disconnect(DisconnectMsg, State, ErrorToDisplay);
 	_:Error ->
 	    Desc = log_error(Error),
 	    handle_disconnect(#ssh_msg_disconnect{code = ?SSH_DISCONNECT_KEY_EXCHANGE_FAILED,
-						  description = Desc,
-						  language = "en"}, State)
+							  description = Desc,
+							  language = "en"}, State)
     end;
 
 key_exchange(#ssh_msg_kex_dh_gex_group{} = Msg, 
@@ -673,6 +675,11 @@ terminate({shutdown, #ssh_msg_disconnect{} = Msg}, StateName, #state{ssh_params
     send_msg(SshPacket, State),
     ssh_connection_manager:event(Pid, Msg),
     terminate(normal, StateName, State#state{ssh_params = Ssh});
+terminate({shutdown, {#ssh_msg_disconnect{} = Msg, ErrorMsg}}, StateName, #state{ssh_params = Ssh0, manager = Pid} = State) ->
+    {SshPacket, Ssh} = ssh_transport:ssh_packet(Msg, Ssh0),
+    send_msg(SshPacket, State),
+    ssh_connection_manager:event(Pid, Msg, ErrorMsg),
+    terminate(normal, StateName, State#state{ssh_params = Ssh});
 terminate(Reason, StateName, #state{ssh_params = Ssh0, manager = Pid} = State) ->
     log_error(Reason),
     DisconnectMsg = 
@@ -950,6 +957,8 @@ handle_ssh_packet(Length, StateName, #state{decoded_data_buffer = DecData0,
 
 handle_disconnect(#ssh_msg_disconnect{} = Msg, State) ->
     {stop, {shutdown, Msg}, State}.
+handle_disconnect(#ssh_msg_disconnect{} = Msg, State, ErrorMsg) ->
+    {stop, {shutdown, {Msg, ErrorMsg}}, State}.
 
 counterpart_versions(NumVsn, StrVsn, #ssh{role = server} = Ssh) ->
     Ssh#ssh{c_vsn = NumVsn , c_version = StrVsn};
diff --git a/lib/ssh/src/ssh_connection_manager.erl b/lib/ssh/src/ssh_connection_manager.erl
index 94a9ed505f..9536eb9dec 100644
--- a/lib/ssh/src/ssh_connection_manager.erl
+++ b/lib/ssh/src/ssh_connection_manager.erl
@@ -40,8 +40,7 @@
 	 close/2, stop/1, send/5,
 	 send_eof/2]).
 
--export([open_channel/6, reply_request/3, request/6, request/7, global_request/4, event/2,
-	 cast/2]).
+-export([open_channel/6, reply_request/3, request/6, request/7, global_request/4, event/2, event/3, cast/2]).
 
 %% Internal application API and spawn
 -export([send_msg/1, ssh_channel_info_handler/3]).
@@ -110,10 +109,11 @@ global_request(ConnectionManager, Type, true = Reply, Data) ->
 
 global_request(ConnectionManager, Type, false = Reply, Data) ->
     cast(ConnectionManager, {global_request, self(), Type, Reply, Data}).
- 
+
+event(ConnectionManager, BinMsg, ErrorMsg) ->
+    call(ConnectionManager, {ssh_msg, self(), BinMsg, ErrorMsg}).
 event(ConnectionManager, BinMsg) -> 
     call(ConnectionManager, {ssh_msg, self(), BinMsg}).
-
 info(ConnectionManager) ->
     info(ConnectionManager, {info, all}).
 
@@ -262,8 +262,7 @@ handle_call({ssh_msg, Pid, Msg}, From,
     
     %% To avoid that not all data sent by the other side is processes before
     %% possible crash in ssh_connection_handler takes down the connection.
-    gen_server:reply(From, ok), 
-
+    gen_server:reply(From, ok),
     ConnectionMsg = decode_ssh_msg(Msg),
     try ssh_connection:handle_msg(ConnectionMsg, Connection0, Pid, Role) of
 	{{replies, Replies}, Connection} ->
@@ -294,7 +293,45 @@ handle_call({ssh_msg, Pid, Msg}, From,
 		disconnect_fun(Reason, SSHOpts),
 		{stop, {shutdown, Error}, State#state{connection_state = Connection}}
 	end;
+handle_call({ssh_msg, Pid, Msg, ErrorMsg}, From,
+	    #state{connection_state = Connection0,
+		   role = Role, opts = Opts, connected = IsConnected,
+		   client = ClientPid}
+	    = State) ->
 
+    %% To avoid that not all data sent by the other side is processes before
+    %% possible crash in ssh_connection_handler takes down the connection.
+    gen_server:reply(From, ok),
+    ConnectionMsg = decode_ssh_msg(Msg),
+    try ssh_connection:handle_msg(ConnectionMsg, Connection0, Pid, Role) of
+	{{replies, Replies}, Connection} ->
+	    lists:foreach(fun send_msg/1, Replies),
+	    {noreply, State#state{connection_state = Connection}};
+	{noreply, Connection} ->
+	    {noreply, State#state{connection_state = Connection}};
+	{disconnect, {_, Reason}, {{replies, Replies}, Connection}}
+	when Role == client andalso (not IsConnected) ->
+	    lists:foreach(fun send_msg/1, Replies),
+	    ClientPid ! {self(), not_connected, {Reason, ErrorMsg}},
+	    {stop, {shutdown, normal}, State#state{connection = Connection}};
+	{disconnect, Reason, {{replies, Replies}, Connection}} ->
+	    lists:foreach(fun send_msg/1, Replies),
+	    SSHOpts = proplists:get_value(ssh_opts, Opts),
+	    disconnect_fun(Reason, SSHOpts),
+	    {stop, {shutdown, normal}, State#state{connection_state = Connection}}
+	catch
+	    _:Error ->
+		{disconnect, Reason, {{replies, Replies}, Connection}} =
+		    ssh_connection:handle_msg(
+		      #ssh_msg_disconnect{code = ?SSH_DISCONNECT_BY_APPLICATION,
+					  description = "Internal error",
+					  language = "en"}, Connection0, undefined,
+		      Role),
+		lists:foreach(fun send_msg/1, Replies),
+		SSHOpts = proplists:get_value(ssh_opts, Opts),
+		disconnect_fun(Reason, SSHOpts),
+		{stop, {shutdown, Error}, State#state{connection_state = Connection}}
+	end;
 handle_call({global_request, Pid, _, _, _} = Request, From, 
 	    #state{connection_state = 
 		   #connection{channel_cache = Cache}} = State0) ->
diff --git a/lib/ssh/src/ssh_transport.erl b/lib/ssh/src/ssh_transport.erl
index 1abb69921d..a47a55b707 100644
--- a/lib/ssh/src/ssh_transport.erl
+++ b/lib/ssh/src/ssh_transport.erl
@@ -356,12 +356,12 @@ handle_kexdh_reply(#ssh_msg_kexdh_reply{public_host_key = HostKey, f = F,
 	    {ok, SshPacket, Ssh#ssh{shared_secret  = K,
 				    exchanged_hash = H,
 				    session_id = sid(Ssh, H)}};
-	_Error ->
+	Error ->
 	    Disconnect = #ssh_msg_disconnect{
 	      code = ?SSH_DISCONNECT_KEY_EXCHANGE_FAILED,
 	      description = "Key exchange failed",
 	      language = "en"},
-	    throw(Disconnect)
+	    throw({Error, Disconnect})
     end.
 
 handle_kex_dh_gex_request(#ssh_msg_kex_dh_gex_request{min = _Min,