ssh: make server check auth_methods when rec request

1 files changed, 70 insertions, 55 deletions

diff --git a/lib/ssh/src/ssh_auth.erl b/lib/ssh/src/ssh_auth.erl
index df9a97c8f8..5610be5878 100644
--- a/lib/ssh/src/ssh_auth.erl
+++ b/lib/ssh/src/ssh_auth.erl
@@ -169,7 +169,8 @@ handle_userauth_request(#ssh_msg_userauth_request{user = User,
 						  service = "ssh-connection",
 						  method = "password",
 						  data = <<?FALSE, ?UINT32(Sz), BinPwd:Sz/binary>>}, _, 
-			#ssh{opts = Opts} = Ssh) ->
+			#ssh{opts = Opts,
+			     userauth_supported_methods = Methods} = Ssh) ->
     Password = unicode:characters_to_list(BinPwd),
     case check_password(User, Password, Opts) of
 	true ->
@@ -178,7 +179,7 @@ handle_userauth_request(#ssh_msg_userauth_request{user = User,
 	false  ->
 	    {not_authorized, {User, {error,"Bad user or password"}}, 
 	     ssh_transport:ssh_packet(#ssh_msg_userauth_failure{
-		     authentications = "",
+		     authentications = Methods,
 		     partial_success = false}, Ssh)}
     end;
 
@@ -191,7 +192,7 @@ handle_userauth_request(#ssh_msg_userauth_request{user = User,
 							   %% ?UINT32(Sz2), NewBinPwd:Sz2/binary
 							 >>
 						 }, _, 
-			Ssh) ->
+			#ssh{userauth_supported_methods = Methods} = Ssh) ->
     %% Password change without us having sent SSH_MSG_USERAUTH_PASSWD_CHANGEREQ (because we never do)
     %% RFC 4252 says:
     %%   SSH_MSG_USERAUTH_FAILURE without partial success - The password
@@ -200,7 +201,7 @@ handle_userauth_request(#ssh_msg_userauth_request{user = User,
 
     {not_authorized, {User, {error,"Password change not supported"}}, 
      ssh_transport:ssh_packet(#ssh_msg_userauth_failure{
-				 authentications = "",
+				 authentications = Methods,
 				 partial_success = false}, Ssh)};
 
 handle_userauth_request(#ssh_msg_userauth_request{user = User,
@@ -216,7 +217,9 @@ handle_userauth_request(#ssh_msg_userauth_request{user = User,
 						  service = "ssh-connection",
 						  method = "publickey",
 						  data = Data}, 
-			SessionId, #ssh{opts = Opts} = Ssh) ->
+			SessionId, 
+			#ssh{opts = Opts,
+			     userauth_supported_methods = Methods} = Ssh) ->
     <<?BYTE(HaveSig), ?UINT32(ALen), BAlg:ALen/binary, 
      ?UINT32(KLen), KeyBlob:KLen/binary, SigWLen/binary>> = Data,
     Alg = binary_to_list(BAlg),
@@ -231,7 +234,7 @@ handle_userauth_request(#ssh_msg_userauth_request{user = User,
 		false ->
 		    {not_authorized, {User, undefined}, 
 		     ssh_transport:ssh_packet(#ssh_msg_userauth_failure{
-			     authentications="publickey,password",
+			     authentications = Methods,
 			     partial_success = false}, Ssh)}
 	    end;
 	?FALSE ->
@@ -245,49 +248,59 @@ handle_userauth_request(#ssh_msg_userauth_request{user = User,
 						  service = "ssh-connection",
 						  method = "keyboard-interactive",
 						  data = _},
-			_, #ssh{opts = Opts} = Ssh) ->
-    %% RFC4256
-    %% The data field contains:
-    %%   - language tag (deprecated). If =/=[] SHOULD use it however. We skip
-    %%                                it for simplicity.
-    %%   - submethods. "... the user can give a hint of which actual methods
-    %%                  he wants to use. ...".  It's a "MAY use" so we skip
-    %%                  it. It also needs an understanding between the client
-    %%                  and the server.
-    %%                  
-    %% "The server MUST reply with an SSH_MSG_USERAUTH_SUCCESS,
-    %%  SSH_MSG_USERAUTH_FAILURE, or SSH_MSG_USERAUTH_INFO_REQUEST message."
-    Default = {"SSH server",
-	       "Enter password for \""++User++"\"",
-	       "pwd: ",
-	       false},
-
-    {Name, Instruction, Prompt, Echo} =
-	case proplists:get_value(auth_method_kb_interactive_data, Opts) of
-	    undefined -> 
-		Default;
-	    {_,_,_,_}=V -> 
-		V;
-	    F when is_function(F) ->
-		{_,PeerName} = Ssh#ssh.peer,
-		F(PeerName, User, "ssh-connection")
-	end,
-    EchoEnc = case Echo of
-		  true -> <<?TRUE>>;
-		  false -> <<?FALSE>>
-	      end,
-    Msg = #ssh_msg_userauth_info_request{name = unicode:characters_to_list(Name),
-					 instruction = unicode:characters_to_list(Instruction),
-					 language_tag = "",
-					 num_prompts = 1,
-					 data = <<?STRING(unicode:characters_to_binary(Prompt)),
-						  EchoEnc/binary
-						>>
-					},
-    {not_authorized, {User, undefined}, 
-     ssh_transport:ssh_packet(Msg, Ssh#ssh{user = User,
-					   opts = [{max_kb_tries,3},{kb_userauth_info_msg,Msg}|Opts]
-					  })};
+			_, #ssh{opts = Opts,
+				userauth_supported_methods = Methods} = Ssh) ->
+    case proplists:get_value(max_kb_tries, Opts, 0) of
+	N when N<1 ->
+	    {not_authorized, {User, {authmethod, "keyboard-interactive"}}, 
+	     ssh_transport:ssh_packet(
+	       #ssh_msg_userauth_failure{authentications = Methods,
+					 partial_success = false}, Ssh)};
+
+	_ ->
+	    %% RFC4256
+	    %% The data field contains:
+	    %%   - language tag (deprecated). If =/=[] SHOULD use it however. We skip
+	    %%                                it for simplicity.
+	    %%   - submethods. "... the user can give a hint of which actual methods
+	    %%                  he wants to use. ...".  It's a "MAY use" so we skip
+	    %%                  it. It also needs an understanding between the client
+	    %%                  and the server.
+	    %%                  
+	    %% "The server MUST reply with an SSH_MSG_USERAUTH_SUCCESS,
+	    %%  SSH_MSG_USERAUTH_FAILURE, or SSH_MSG_USERAUTH_INFO_REQUEST message."
+	    Default = {"SSH server",
+		       "Enter password for \""++User++"\"",
+		       "pwd: ",
+		       false},
+
+	    {Name, Instruction, Prompt, Echo} =
+		case proplists:get_value(auth_method_kb_interactive_data, Opts) of
+		    undefined -> 
+			Default;
+		    {_,_,_,_}=V -> 
+			V;
+		    F when is_function(F) ->
+			{_,PeerName} = Ssh#ssh.peer,
+			F(PeerName, User, "ssh-connection")
+		end,
+	    EchoEnc = case Echo of
+			  true -> <<?TRUE>>;
+			  false -> <<?FALSE>>
+		      end,
+	    Msg = #ssh_msg_userauth_info_request{name = unicode:characters_to_list(Name),
+						 instruction = unicode:characters_to_list(Instruction),
+						 language_tag = "",
+						 num_prompts = 1,
+						 data = <<?STRING(unicode:characters_to_binary(Prompt)),
+							  EchoEnc/binary
+							>>
+						},
+	    {not_authorized, {User, undefined}, 
+	     ssh_transport:ssh_packet(Msg, Ssh#ssh{user = User,
+						   opts = [{kb_userauth_info_msg,Msg}|Opts]
+						  })}
+    end;
 
 handle_userauth_request(#ssh_msg_userauth_request{user = User,
 						  service = "ssh-connection",
@@ -315,7 +328,8 @@ handle_userauth_info_request(
 handle_userauth_info_response(#ssh_msg_userauth_info_response{num_responses = 1,
 							      data = <<?UINT32(Sz), Password:Sz/binary>>},
 			      #ssh{opts = Opts0,
-				   user = User} = Ssh) ->
+				   user = User,
+				   userauth_supported_methods = Methods} = Ssh) ->
     NumTriesLeft = proplists:get_value(max_kb_tries, Opts0, 0) - 1,
     Opts = lists:keydelete(max_kb_tries,1,Opts0),
     case check_password(User, unicode:characters_to_list(Password), Opts) of
@@ -327,10 +341,11 @@ handle_userauth_info_response(#ssh_msg_userauth_info_response{num_responses = 1,
 		(proplists:get_value(kb_userauth_info_msg,Opts))
 		#ssh_msg_userauth_info_request{name = "",
 					       instruction = 
-						   lists:concat(
-						     ["Bad user or password, try again. ",
-						      integer_to_list(NumTriesLeft),
-						      " tries left."])},
+					       	   lists:concat(
+					       	     ["Bad user or password, try again. ",
+					       	      integer_to_list(NumTriesLeft),
+					       	      " tries left."])
+					      },
 	    {not_authorized, {User, undefined}, 
 	     ssh_transport:ssh_packet(UserAuthInfoMsg,
 				      Ssh#ssh{opts = [{max_kb_tries,NumTriesLeft}|Opts]})};
@@ -338,7 +353,7 @@ handle_userauth_info_response(#ssh_msg_userauth_info_response{num_responses = 1,
 	false ->
 	    {not_authorized, {User, {error,"Bad user or password"}}, 
 	     ssh_transport:ssh_packet(#ssh_msg_userauth_failure{
-					 authentications = "",
+					 authentications = Methods,
 					 partial_success = false}, 
 				      Ssh#ssh{opts = lists:keydelete(kb_userauth_info_msg,1,Opts)}
 				     )}