diff --git a/apps/emqx/src/emqx_guid.erl b/apps/emqx/src/emqx_guid.erl
index a156abac6..9b51e92c8 100644
--- a/apps/emqx/src/emqx_guid.erl
+++ b/apps/emqx/src/emqx_guid.erl
@@ -145,10 +145,10 @@ npid() ->
     NPid.
 
 to_hexstr(I) when byte_size(I) =:= 16 ->
-    emqx_misc:bin2hexstr_A_F(I).
+    emqx_misc:bin_to_hexstr(I, upper).
 
 from_hexstr(S) when byte_size(S) =:= 32 ->
-    emqx_misc:hexstr2bin(S).
+    emqx_misc:hexstr_to_bin(S).
 
 to_base62(<<I:128>>) ->
     emqx_base62:encode(I).
diff --git a/apps/emqx/src/emqx_misc.erl b/apps/emqx/src/emqx_misc.erl
index f2c4c6b79..f216b61e3 100644
--- a/apps/emqx/src/emqx_misc.erl
+++ b/apps/emqx/src/emqx_misc.erl
@@ -53,9 +53,8 @@
 ]).
 
 -export([
-    bin2hexstr_A_F/1,
-    bin2hexstr_a_f/1,
-    hexstr2bin/1
+    bin_to_hexstr/2,
+    hexstr_to_bin/1
 ]).
 
 -export([clamp/3]).
@@ -304,20 +303,18 @@ index_of(E, I, [E | _]) ->
 index_of(E, I, [_ | L]) ->
     index_of(E, I + 1, L).
 
--spec bin2hexstr_A_F(binary()) -> binary().
-bin2hexstr_A_F(B) when is_binary(B) ->
-    <<<<(int2hexchar(H, upper)), (int2hexchar(L, upper))>> || <<H:4, L:4>> <= B>>.
-
--spec bin2hexstr_a_f(binary()) -> binary().
-bin2hexstr_a_f(B) when is_binary(B) ->
+-spec bin_to_hexstr(binary(), lower | upper) -> binary().
+bin_to_hexstr(B, upper) when is_binary(B) ->
+    <<<<(int2hexchar(H, upper)), (int2hexchar(L, upper))>> || <<H:4, L:4>> <= B>>;
+bin_to_hexstr(B, lower) when is_binary(B) ->
     <<<<(int2hexchar(H, lower)), (int2hexchar(L, lower))>> || <<H:4, L:4>> <= B>>.
 
 int2hexchar(I, _) when I >= 0 andalso I < 10 -> I + $0;
 int2hexchar(I, upper) -> I - 10 + $A;
 int2hexchar(I, lower) -> I - 10 + $a.
 
--spec hexstr2bin(binary()) -> binary().
-hexstr2bin(B) when is_binary(B) ->
+-spec hexstr_to_bin(binary()) -> binary().
+hexstr_to_bin(B) when is_binary(B) ->
     <<<<(hexchar2int(H) * 16 + hexchar2int(L))>> || <<H:8, L:8>> <= B>>.
 
 hexchar2int(I) when I >= $0 andalso I =< $9 -> I - $0;
diff --git a/apps/emqx/src/emqx_trace/emqx_trace_handler.erl b/apps/emqx/src/emqx_trace/emqx_trace_handler.erl
index 424fb04ed..c249d5aee 100644
--- a/apps/emqx/src/emqx_trace/emqx_trace_handler.erl
+++ b/apps/emqx/src/emqx_trace/emqx_trace_handler.erl
@@ -190,7 +190,7 @@ handler_id(Name, Type) ->
         do_handler_id(Name, Type)
     catch
         _:_ ->
-            Hash = emqx_misc:bin2hexstr_a_f(crypto:hash(md5, Name)),
+            Hash = emqx_misc:bin_to_hexstr(crypto:hash(md5, Name), lower),
             do_handler_id(Hash, Type)
     end.
 
diff --git a/apps/emqx_rule_engine/src/emqx_rule_funcs.erl b/apps/emqx_rule_engine/src/emqx_rule_funcs.erl
index 1c887327c..12a2af127 100644
--- a/apps/emqx_rule_engine/src/emqx_rule_funcs.erl
+++ b/apps/emqx_rule_engine/src/emqx_rule_funcs.erl
@@ -20,6 +20,8 @@
 -include_lib("emqx/include/emqx.hrl").
 -include_lib("emqx/include/logger.hrl").
 
+-elvis([{elvis_style, god_modules, disable}]).
+
 %% IoT Funcs
 -export([
     msgid/0,
@@ -617,10 +619,10 @@ map(Data) ->
     emqx_plugin_libs_rule:map(Data).
 
 bin2hexstr(Bin) when is_binary(Bin) ->
-    emqx_misc:bin2hexstr_A_F(Bin).
+    emqx_misc:bin_to_hexstr(Bin, upper).
 
 hexstr2bin(Str) when is_binary(Str) ->
-    emqx_misc:hexstr2bin(Str).
+    emqx_misc:hexstr_to_bin(Str).
 
 %%------------------------------------------------------------------------------
 %% NULL Funcs
@@ -885,7 +887,7 @@ sha256(S) when is_binary(S) ->
     hash(sha256, S).
 
 hash(Type, Data) ->
-    emqx_misc:bin2hexstr_a_f(crypto:hash(Type, Data)).
+    emqx_misc:bin_to_hexstr(crypto:hash(Type, Data), lower).
 
 %%------------------------------------------------------------------------------
 %% Data encode and decode Funcs