ecrecover/src/nifecrecover.erl
2019-08-05 15:05:14 +02:00

61 lines
1.4 KiB
Erlang

-module(nifecrecover).
%% API
-export([ecrecover/1,
ecrecover_hex/1,
bin_to_hexstr/1,
hexstr_to_bin/1,
time_taken_to_execute/1
]).
%% Native library support
-export([load/0]).
-on_load(load/0).
ecrecover(_Input) ->
not_loaded(?LINE).
ecrecover_hex(Input) ->
Decoded = hexstr_to_bin(Input),
{ok, PubKey} = ecrecover(Decoded),
Encoded = bin_to_hexstr(PubKey),
Encoded.
load() ->
ok = erlang:load_nif("/home/newby/projects/ethereum/ecrecover/target/release/libecrecover", 0).
not_loaded(Line) ->
erlang:nif_error({error, {not_loaded, [{module, ?MODULE}, {line, Line}]}}).
priv()->
case code:priv_dir(?MODULE) of
{error, _} ->
EbinDir = filename:dirname(code:which(?MODULE)),
AppPath = filename:dirname(EbinDir),
filename:join(AppPath, "priv");
Path ->
Path
end.
%%
time_taken_to_execute(F) -> Start = os:timestamp(),
F(),
io:format("total time taken ~f seconds~n", [timer:now_diff(os:timestamp(), Start) / 1000000]).
%%
bin_to_hexstr(Bin) ->
lists:flatten([io_lib:format("~2.16.0B", [X]) ||
X <- binary_to_list(Bin)]).
hexstr_to_bin(S) ->
hexstr_to_bin(S, []).
hexstr_to_bin([], Acc) ->
list_to_binary(lists:reverse(Acc));
hexstr_to_bin([X,Y|T], Acc) ->
{ok, [V], []} = io_lib:fread("~16u", [X,Y]),
hexstr_to_bin(T, [V | Acc]);
hexstr_to_bin([X|T], Acc) ->
{ok, [V], []} = io_lib:fread("~16u", lists:flatten([X,"0"])),
hexstr_to_bin(T, [V | Acc]).