Switched to C based nif

src/ecrecover.app.src

@@ -4,8 +4,7 @@
   {registered, []},
   {applications,
    [kernel,
-    stdlib,
-    ecrecoverprebuilt
+    stdlib
    ]},
   {env,[]},
   {modules, []},

src/ecrecover.erl

@@ -1,7 +1,9 @@
 -module(ecrecover).
 
+%% https://github.com/mbrix/libsecp256k1
+
 %% API
--export([recover/2]).
+-export([recover/2, recover/3]).
 
 %% NIF
 -export([load/0]).
@@ -9,16 +11,17 @@
 
 %%=============================================================================
 %% NIF API
+%% GoodMsg1 = <<71,23,50,133,168,215,52,30,94,151,47,198,119,40,99,132,248,2,248,239,66,165,236,95,3,187,250,37,76,176,31,173>>.
+%% GoodSig1_v = <<27,101,10,207,157,63,95,10,44,121,151,118,161,37,67,85,213,244,6,23,98,162,55,57,106,153,160,224,227,252,43,205,103,41,81,74,13,172,178,230,35,172,74,189,21,124,177,129,99,255,148,34,128,219,77,92,170,214,109,223,148,27,161,46,3>>.
+%% ecrecover:recover(<<71,23,50,133,168,215,52,30,94,151,47,198,119,40,99,132,248,2,248,239,66,165,236,95,3,187,250,37,76,176,31,173>>, <<27,101,10,207,157,63,95,10,44,121,151,118,161,37,67,85,213,244,6,23,98,162,55,57,106,153,160,224,227,252,43,205,103,41,81,74,13,172,178,230,35,172,74,189,21,124,177,129,99,255,148,34,128,219,77,92,170,214,109,223,148,27,161,46,3>>).
+%% 
 
 load() ->
-    % Prefer locally built NIF (good for testing and exotic platforms) over
-    % prebuilt binaries.
-    case load_local_nif() of
-        ok ->
-            ok;
-        {error, _} ->
-            load_prebuilt_nif()
-    end.
+    EbinDir = filename:dirname(code:which(?MODULE)),
+    AppDir = filename:dirname(EbinDir),
+    PrivDir = filename:join(AppDir, "priv"),
+    SoName = filename:join(PrivDir, atom_to_list(?MODULE)),
+    erlang:load_nif(SoName, 0).
 
 not_loaded(Line) ->
     erlang:nif_error({error, {not_loaded, [{module, ?MODULE}, {line, Line}]}}).
@@ -26,36 +29,22 @@ not_loaded(Line) ->
 %%=============================================================================
 %% External API
 
--spec recover(<<_:(32*8)>>, <<_:(65*8)>>) -> <<_:(32*8)>>.
-recover(<<_:32/binary>> = Hash, <<_:65/binary>> = Sig) ->
-    Input = <<Hash/binary, 0:(8*31), Sig/binary>>,
-    case recover_(Input) of
-        {ok, []} ->
-            <<0:256>>;
-        {ok, Res} ->
-            erlang:list_to_binary(Res);
-        _Err ->
+recover(Hash, <<V, Sig:64/binary>>) when V == 27; V == 28 ->
+    RecId = V - 27,
+    case recover(Hash, Sig, RecId) of
+        {ok, <<4, XY:64/binary>>} ->
+            <<_:12/bytes, ShortPub:20/bytes>> = keccak256(XY),
+            <<0:96, ShortPub/binary>>;
+        {error, _} ->
             <<0:256>>
-    end.
+        end.
+
+-spec recover(<<_:(32*8)>>, <<_:(65*8)>>, integer()) -> <<_:(32*8)>>.
+recover(_Hash, _Sig, _RecId) ->
+    not_loaded(?LINE).
 
 %%=============================================================================
 %% Internal Functions
 
-load_local_nif() ->
-    EbinDir = filename:dirname(code:which(?MODULE)),
-    AppDir = filename:dirname(EbinDir),
-    PrivDir = filename:join(AppDir, "priv"),
-    SoName = filename:join(PrivDir, atom_to_list(?MODULE)),
-    erlang:load_nif(SoName, 0).
-
-load_prebuilt_nif() ->
-    case code:priv_dir(ecrecoverprebuilt) of
-        {error, _} ->
-            {error, prebuilt_priv_dir_not_found};
-        PrivDir ->
-            SoName = filename:join(PrivDir, atom_to_list(?MODULE)),
-            erlang:load_nif(SoName, 0)
-    end.
-
-recover_(_Input) ->
-    not_loaded(?LINE).
+keccak256(Bin) ->
+    sha3:hash(256, Bin).

src/ecrecover_util.erl

@@ -1,28 +0,0 @@
--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]).

src/lib.rs

@@ -1,42 +0,0 @@
-extern crate c_vec;
-extern crate ethcore_builtin;
-#[macro_use]
-extern crate lazy_static;
-extern crate libc;
-extern crate parity_bytes;
-#[macro_use]
-extern crate rustler;
-
-use crate::ethcore_builtin::Implementation;
-use ethcore_builtin::EcRecover;
-use parity_bytes::BytesRef;
-use rustler::*;
-
-mod atoms {
-    rustler_atoms! {
-        atom ok;
-    }
-}
-
-rustler_export_nifs!(
-    "ecrecover",
-    [("recover_", 1, nif_ecrecover),],
-    Some(on_load)
-);
-
-#[no_mangle]
-fn on_load(_env: Env, _load_info: Term) -> bool {
-    true
-}
-
-pub fn nif_ecrecover<'a>(env: Env<'a>, args: &[Term<'a>]) -> Result<Term<'a>, Error> {
-    let input: Binary = args[0].decode()?;
-    let mut byte_ref = Vec::new();
-    let ecrecover = EcRecover {};
-    let _result = match ecrecover.execute(input.as_slice(), &mut BytesRef::Flexible(&mut byte_ref))
-    {
-        Ok(_) => (),
-        Err(_e) => return Err(rustler::Error::Atom("ecrecover_failed")),
-    };
-    Ok((atoms::ok(), byte_ref.as_slice()).encode(env))
-}