Fix crash when SASL PLAIN denies auth (EJAB-1425)

src/cyrsasl.erl

@@ -204,7 +204,7 @@ server_new(Service, ServerFQDN, UserRealm, _SecFlags,
 %%     Continue = {continue, ServerOut, New_State}
 %%         ServerOut = string()
 %%         New_State = saslstate()
-%%     Error = {error, Reason} | {error, Username, Reason}
+%%     Error = {error, Reason} | {error, Reason, Username}
 %%         Reason = term()
 %%         Username = string()
 
@@ -236,8 +236,9 @@ server_start(State, Mech, ClientIn) ->
 %%     Continue = {continue, ServerOut, New_State}
 %%         ServerOut = string()
 %%         New_State = saslstate()
-%%     Error = {error, Reason} | {error, Username, Reason}
+%%     Error = {error, Reason} | {error, Reason, Text, Username}
 %%         Reason = term()
+%%         Text = string()
 %%         Username = string()
 
 server_step(State, ClientIn) ->
@@ -254,8 +255,8 @@ server_step(State, ClientIn) ->
 	{continue, ServerOut, NewMechState} ->
 	    {continue, ServerOut,
 	     State#sasl_state{mech_state = NewMechState}};
-	{error, Error, Username} ->
+	{error, Error, Text, Username} ->
-	    {error, Error, Username};
+	    {error, Error, Text, Username};
 	{error, Error} ->
 	    {error, Error}
     end.

src/cyrsasl_digest.erl

@@ -80,7 +80,7 @@ mech_new(#sasl_params{host=Host, get_password=GetPassword,
 %%     Continue = {continue, ServerOut, New_State}
 %%         ServerOut = string()
 %%         New_State = mechstate()
-%%     Error = {error, Reason} | {error, Reason, Username}
+%%     Error = {error, Reason} | {error, Reason, Text, Username}
 %%         Reason = term()
 
 mech_step(#state{step = 1, nonce = Nonce} = State, _) ->
@@ -99,12 +99,12 @@ mech_step(#state{step = 3, nonce = Nonce} = State, ClientIn) ->
 		false ->
 		    ?DEBUG("User login not authorized because digest-uri "
 			   "seems invalid: ~p", [DigestURI]),
-		    {error, 'not-authorized', UserName};
+		    {error, 'not-authorized', "", UserName};
 		true ->
 		    AuthzId = proplists:get_value("authzid", KeyVals, ""),
 		    case (State#state.get_password)(UserName) of
 			{false, _} ->
-			    {error, 'not-authorized', UserName};
+			    {error, 'not-authorized', "", UserName};
 			{Passwd, AuthModule} ->
 				case (State#state.check_password)(UserName, "",
 					proplists:get_value("response", KeyVals, ""),
@@ -121,9 +121,9 @@ mech_step(#state{step = 3, nonce = Nonce} = State, ClientIn) ->
 						 username = UserName,
 						 authzid = AuthzId}};
 				false ->
-				    {error, 'not-authorized', UserName};
+				    {error, 'not-authorized', "", UserName};
 				{false, _} ->
-				    {error, 'not-authorized', UserName}
+				    {error, 'not-authorized', "", UserName}
 			    end
 		    end
 	    end

src/cyrsasl_gssapi.erl

@@ -128,13 +128,13 @@ do_step(#state{needsmore=true,sasl=Sasl,step=Step}=State, ClientIn) ->
 	{needsmore, RspAuth} ->
 	    ?DEBUG("needsmore~n", []),
 	    if (Step > 0) and (ClientIn =:= []) and (RspAuth =:= <<>>) ->
-		    {error, "not-authorized"};
+		    {error, 'not-authorized'};
 		true ->
 		    {continue, binary_to_list(RspAuth),
 		     State#state{step=Step+1}}
 	    end;
 	{error, _} ->
-	    {error, "not-authorized"}
+	    {error, 'not-authorized'}
     end.
 
 handle_step_ok(State, []) ->
@@ -147,7 +147,7 @@ check_user(#state{authid=Authid,authzid=Authzid,
 		  authrealm=Auth_realm,host=Host,realm=Realm}) ->
     if Realm =/= Auth_realm ->
 	    ?DEBUG("bad realm ~p (expected ~p)~n",[Auth_realm, Realm]),
-	    throw({error, "not-authorized"});
+	    throw({error, 'not-authorized'});
        true ->
 	    ok
     end,
@@ -155,7 +155,7 @@ check_user(#state{authid=Authid,authzid=Authzid,
     case ejabberd_auth:is_user_exists(Authid, Host) of
 	false ->
 	    ?DEBUG("bad user ~p~n",[Authid]),
-	    throw({error, "not-authorized"});
+	    throw({error, 'not-authorized'});
 	true ->
 	    ok
     end,

src/cyrsasl_plain.erl

@@ -62,8 +62,7 @@ mech_new(#sasl_params{check_password = CheckPassword}) ->
 %%         Username = string()
 %%         AuthzId = string()
 %%         AuthModule = atom()
-%%     Error = {error, Reason} | {error, Reason, Username}
+%%     Error = {error, Reason} | {error, Reason, Text, Username}
-%%         Reason = term()
 
 mech_step(State, ClientIn) ->
     case prepare(ClientIn) of
@@ -73,9 +72,9 @@ mech_step(State, ClientIn) ->
 		    {ok, [{username, User}, {authzid, AuthzId},
 			  {auth_module, AuthModule}]};
 		{false, ReasonAuthFail} when is_list(ReasonAuthFail) ->
-		    {error, ReasonAuthFail, User};
+		    {error, 'not-authorized', ReasonAuthFail, User};
 		_ ->
-		    {error, 'not-authorized', User}
+		    {error, 'not-authorized', "", User}
 	    end;
 	_ ->
 	    {error, 'bad-protocol'}

src/ejabberd_auth.erl

@@ -141,7 +141,8 @@ check_password(User, Server, Password, Digest, DigestGen)
 %%     {true, AuthModule} | {false, Reason::string()}
 %% where
 %%   AuthModule = ejabberd_auth_anonymous | ejabberd_auth_external
-%%           | ejabberd_auth_ldap | ejabberd_auth_pam | ejabberd_auth_storage
+%%                 | ejabberd_auth_internal | ejabberd_auth_ldap
+%%                 | ejabberd_auth_odbc | ejabberd_auth_pam
 %% @doc Check if the user and password can login in server.
 %% The user can login if at least an authentication method accepts the user
 %% and the password.

src/ejabberd_c2s.erl

@@ -716,13 +716,13 @@ wait_for_feature_request({xmlstreamelement, #xmlel{ns = NS, name = Name} = El},
 		    fsm_next_state(wait_for_sasl_response,
 				   StateData#state{
 				     sasl_state = NewSASLState});
-		{error, Error, Username} when is_list(Error) ->
+		{error, Error, Text, Username} ->
 		    ?INFO_MSG(
-		       "(~w) Failed authentication for ~s@~s due to ~s",
+		       "(~w) Failed authentication for ~s@~s due to ~p ~s",
 		       [StateData#state.socket,
-			Username, StateData#state.server, Error]),
+			Username, StateData#state.server, Error, Text]),
 		    send_element(StateData,
-		      exmpp_server_sasl:failure(Error)),
+		      exmpp_server_sasl:failure(Error, Text)),
 		    {next_state, wait_for_feature_request, StateData,
 		     ?C2S_OPEN_TIMEOUT};
 		{error, Error} ->
@@ -834,13 +834,13 @@ wait_for_sasl_response({xmlstreamelement, #xmlel{ns = NS, name = Name} = El},
 		      exmpp_server_sasl:challenge(ServerOut)),
 		    fsm_next_state(wait_for_sasl_response,
 		     StateData#state{sasl_state = NewSASLState});
-		{error, Error, Username} ->
+		{error, Error, Text, Username} ->
 		    ?INFO_MSG(
-		       "(~w) Failed authentication for ~s@~s",
+		       "(~w) Failed authentication for ~s@~s due to ~p ~s",
 		       [StateData#state.socket,
-			Username, StateData#state.server]),
+			Username, StateData#state.server, Error, Text]),
 		    send_element(StateData,
-		      exmpp_server_sasl:failure(Error)),
+		      exmpp_server_sasl:failure(Error, Text)),
 		    fsm_next_state(wait_for_feature_request, StateData);
 		{error, Error} ->
 		    send_element(StateData,