fix(jwt): support non-integer timestamp claims

apps/emqx_auth_jwt/src/emqx_auth_jwt.erl

@@ -26,6 +26,8 @@
         , description/0
         ]).
 
+-export([binary_to_number/1]).
+
 %%--------------------------------------------------------------------
 %% Authentication callbacks
 %%--------------------------------------------------------------------
@@ -56,16 +58,12 @@ check_acl(ClientInfo = #{jwt_claims := Claims},
           #{acl_claim_name := AclClaimName}) ->
     case Claims of
         #{AclClaimName := Acl, <<"exp">> := Exp} ->
-            try is_expired(Exp) of
+            case is_expired(Exp) of
                 true ->
                     ?DEBUG("acl_deny_due_to_jwt_expired", []),
                     deny;
                 false ->
                     verify_acl(ClientInfo, Acl, PubSub, Topic)
-            catch
-                _:_ ->
-                    ?DEBUG("acl_deny_due_to_invalid_jwt_exp", []),
-                    deny
             end;
         #{AclClaimName := Acl} ->
             verify_acl(ClientInfo, Acl, PubSub, Topic);
@@ -75,14 +73,40 @@ check_acl(ClientInfo = #{jwt_claims := Claims},
     end.
 
 is_expired(Exp) when is_binary(Exp)  ->
-    ExpInt  = binary_to_integer(Exp),
-    is_expired(ExpInt);
-is_expired(Exp) ->
+    case binary_to_number(Exp) of
+        {ok, Val} ->
+            is_expired(Val);
+        _ ->
+            ?DEBUG("acl_deny_due_to_invalid_jwt_exp:~p", [Exp]),
+            true
+    end;
+is_expired(Exp) when is_integer(Exp) ->
     Now = erlang:system_time(second),
-    Now > Exp.
+    Now > Exp;
+is_expired(Exp) ->
+    ?DEBUG("acl_deny_due_to_invalid_jwt_exp:~p", [Exp]),
+    true.
 
 description() -> "Authentication with JWT".
 
+binary_to_number(Bin) ->
+    Checker = fun([], _) ->
+                      false;
+                 ([H | T], Self) ->
+                      try
+                           {ok, H(Bin)}
+                      catch _:_ ->
+                              Self(T, Self)
+                      end
+              end,
+
+    Checker([fun erlang:binary_to_integer/1,
+            fun(In) ->
+                    Val = erlang:binary_to_float(In),
+                    erlang:round(Val)
+            end],
+           Checker).
+
 %%------------------------------------------------------------------------------
 %% Verify Claims
 %%--------------------------------------------------------------------

apps/emqx_auth_jwt/src/emqx_auth_jwt_svr.erl

@@ -215,13 +215,13 @@ with_int_value(Fun) ->
             case Value of
                 Int when is_integer(Int) -> Fun(Int);
                 Bin when is_binary(Bin) ->
-                    case string:to_integer(Bin) of
-                        {Int, <<>>} -> Fun(Int);
+                    case emqx_auth_jwt:binary_to_number(Bin) of
+                        {ok, Int} -> Fun(Int);
                         _ -> false
                     end;
                 Str when is_list(Str) ->
-                    case string:to_integer(Str) of
-                        {Int, ""} -> Fun(Int);
+                    case emqx_auth_jwt:binary_to_number(Str) of
+                        {ok, Int} -> Fun(Int);
                         _ -> false
                     end
             end

apps/emqx_auth_jwt/test/emqx_auth_jwt_SUITE.erl

@@ -164,7 +164,18 @@ t_check_auth_str_exp(_Config) ->
 
     Result1 = emqx_access_control:authenticate(Plain#{password => Jwt1}),
     ct:pal("Auth result: ~p~n", [Result1]),
-    ?assertMatch({error, _}, Result1).
+    ?assertMatch({error, _}, Result1),
+
+    Exp2 = float_to_binary(os:system_time(seconds) + 3.5),
+
+    Jwt2 = sign([{clientid, <<"client1">>},
+                 {username, <<"plain">>},
+                 {exp, Exp2}], <<"HS256">>, <<"emqxsecret">>),
+    ct:pal("Jwt: ~p~n", [Jwt2]),
+
+    Result2 = emqx_access_control:authenticate(Plain#{password => Jwt2}),
+    ct:pal("Auth result: ~p~n", [Result2]),
+    ?assertMatch({ok, #{auth_result := success, jwt_claims := _}}, Result2).
 
 t_check_claims(init, _Config) ->
     application:set_env(emqx_auth_jwt, verify_claims, [{sub, <<"value">>}]).