Updated README

2023-01-12 15:12:13 +01:00
parent 53b4d36a29
commit 2946ac84f8
3 changed files with 43 additions and 15 deletions
@@ -0,0 +1,28 @@
+-module(ecrecover_util).
+
+-export([ recover_from_hex/1
+        , bin_to_hex/1
+        , hex_to_bin/1
+        ]).
+
+%%=============================================================================
+%% External API
+
+recover_from_hex(Input) ->
+    <<Hash:32/binary, _:31/binary, Sig:65/binary>> = hex_to_bin(Input),
+    PubKey = ecrecover:recover(Hash, Sig),
+    bin_to_hex(PubKey).
+
+bin_to_hex(Bin) ->
+    lists:flatten([io_lib:format("~2.16.0B", [X]) || X <- binary_to_list(Bin)]).
+
+hex_to_bin(S) ->
+    hex_to_bin(S, []).
+hex_to_bin([], Acc) ->
+    list_to_binary(lists:reverse(Acc));
+hex_to_bin([X,Y|T], Acc) ->
+    {ok, [V], []} = io_lib:fread("~16u", [X,Y]),
+    hex_to_bin(T, [V | Acc]);
+hex_to_bin([X|T], Acc) ->
+    {ok, [V], []} = io_lib:fread("~16u", lists:flatten([X,"0"])),
+    hex_to_bin(T, [V | Acc]).