Switched to C based nif

c_src/ecrecover.c

@@ -0,0 +1,102 @@
+#include "erl_nif.h"
+#include "secp256k1_recovery.h"
+
+
+static secp256k1_context *ctx = NULL;
+
+static ERL_NIF_TERM error_result(ErlNifEnv* env, char* error_msg)
+{
+    return enif_make_tuple2(env, enif_make_atom(env, "error"), enif_make_string(env, error_msg, ERL_NIF_LATIN1));
+}
+
+static ERL_NIF_TERM ok_result(ErlNifEnv* env, ERL_NIF_TERM *r)
+{
+    return enif_make_tuple2(env, enif_make_atom(env, "ok"), *r);
+}
+
+static ERL_NIF_TERM
+recover(ErlNifEnv* env, int argc, const ERL_NIF_TERM argv[])
+{
+  ERL_NIF_TERM r;
+	ErlNifBinary message, csignature;
+	int result;
+    int compressed = SECP256K1_EC_UNCOMPRESSED;
+	size_t pubkeylen = 65;
+	int recid;
+    unsigned char* finished_recpubkey_buf;
+    secp256k1_ecdsa_recoverable_signature signature;
+    secp256k1_pubkey recpubkey;
+	
+	if (!enif_inspect_binary(env, argv[0], &message)) {
+       return enif_make_badarg(env);
+    }
+
+	if (!enif_inspect_binary(env, argv[1], &csignature)) {
+       return enif_make_badarg(env);
+    }
+
+    if (!enif_get_int(env, argv[2], &recid)) {
+		return error_result(env, "Recovery id invalid 0-3");
+	}
+
+    if (recid < 0 || recid > 3) {
+		error_result(env, "Recovery id invalid 0-3x");
+	}
+printf("xx1\r\n");
+    result = secp256k1_ecdsa_recoverable_signature_parse_compact(ctx, &signature, csignature.data, recid);
+printf("xx2\r\n");
+	if (!result) {
+		return error_result(env, "ecdsa_signature_parse_compact returned 0");
+	}
+
+	// Now do ECDSA recovery
+	result = secp256k1_ecdsa_recover(ctx, &recpubkey, &signature, message.data);
+
+	if (!result) {
+	    return error_result(env, "ecdsa recovery problem");
+	}
+
+	// Now serialize recpubkey based on the compression flag
+	finished_recpubkey_buf = enif_make_new_binary(env, pubkeylen, &r);
+
+    printf("pubker[0] = %d\r\n", recpubkey.data[0]);
+
+
+	result = secp256k1_ec_pubkey_serialize(ctx, finished_recpubkey_buf,
+			&pubkeylen, &recpubkey, compressed);
+
+	if (!result) {
+		return error_result(env, "ecdsa pubkey serialize error");
+	}
+
+    return ok_result(env, &r);
+
+}
+
+
+static int
+load(ErlNifEnv* env, void** priv, ERL_NIF_TERM load_info)
+{
+    ctx = secp256k1_context_create(SECP256K1_CONTEXT_SIGN | SECP256K1_CONTEXT_VERIFY);
+    return 0;
+}
+
+static int
+upgrade(ErlNifEnv* env, void** priv, void** old_priv, ERL_NIF_TERM load_info)
+{
+    return 0;
+}
+
+static void
+unload(ErlNifEnv* env, void* priv)
+{
+	secp256k1_context_destroy(ctx);
+    return;
+}
+
+static ErlNifFunc nif_funcs[] =
+  {
+   {"recover", 3, recover}
+  };
+
+ERL_NIF_INIT(ecrecover, nif_funcs, &load, NULL, NULL, &unload);