frost/secp256k1-zkp
3
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

Split ecdsa_sign logic into a new function and use it from ecdsa_sign and recovery

Browse Source
This commit is contained in:
Elichai Turkel
2020-05-27 00:37:59 +03:00
parent 5e1c885efb
commit 2876af4f8d
3 changed files with 44 additions and 47 deletions
Download Patch File Download Diff File Expand all files Collapse all files

38
src/secp256k1.c
View File

@@ -467,19 +467,18 @@ static int nonce_function_rfc6979(unsigned char *nonce32, const unsigned char *m
const secp256k1_nonce_function secp256k1_nonce_function_rfc6979 = nonce_function_rfc6979;
const secp256k1_nonce_function secp256k1_nonce_function_default = nonce_function_rfc6979;
int secp256k1_ecdsa_sign(const secp256k1_context* ctx, secp256k1_ecdsa_signature *signature, const unsigned char *msg32, const unsigned char *seckey, secp256k1_nonce_function noncefp, const void* noncedata) {
/* Default initialization here is important so we won't pass uninit values to the cmov in the end */
secp256k1_scalar r = secp256k1_scalar_zero, s = secp256k1_scalar_zero;
static int secp256k1_ecdsa_sign_inner(const secp256k1_context* ctx, secp256k1_scalar* r, secp256k1_scalar* s, int* recid, const unsigned char *msg32, const unsigned char *seckey, secp256k1_nonce_function noncefp, const void* noncedata) {
secp256k1_scalar sec, non, msg;
int ret = 0;
int is_sec_valid;
unsigned char nonce32[32];
unsigned int count = 0;
VERIFY_CHECK(ctx != NULL);
ARG_CHECK(secp256k1_ecmult_gen_context_is_built(&ctx->ecmult_gen_ctx));
ARG_CHECK(msg32 != NULL);
ARG_CHECK(signature != NULL);
ARG_CHECK(seckey != NULL);
/* Default initialization here is important so we won't pass uninit values to the cmov in the end */
*r = secp256k1_scalar_zero;
*s = secp256k1_scalar_zero;
if (recid) {
*recid = 0;
}
if (noncefp == NULL) {
noncefp = secp256k1_nonce_function_default;
}
@@ -498,7 +497,7 @@ int secp256k1_ecdsa_sign(const secp256k1_context* ctx, secp256k1_ecdsa_signature
/* The nonce is still secret here, but it being invalid is is less likely than 1:2^255. */
secp256k1_declassify(ctx, &is_nonce_valid, sizeof(is_nonce_valid));
if (is_nonce_valid) {
ret = secp256k1_ecdsa_sig_sign(&ctx->ecmult_gen_ctx, &r, &s, &sec, &msg, &non, NULL);
ret = secp256k1_ecdsa_sig_sign(&ctx->ecmult_gen_ctx, r, s, &sec, &msg, &non, recid);
/* The final signature is no longer a secret, nor is the fact that we were successful or not. */
secp256k1_declassify(ctx, &ret, sizeof(ret));
if (ret) {
@@ -515,8 +514,25 @@ int secp256k1_ecdsa_sign(const secp256k1_context* ctx, secp256k1_ecdsa_signature
secp256k1_scalar_clear(&msg);
secp256k1_scalar_clear(&non);
secp256k1_scalar_clear(&sec);
secp256k1_scalar_cmov(&r, &secp256k1_scalar_zero, !ret);
secp256k1_scalar_cmov(&s, &secp256k1_scalar_zero, !ret);
secp256k1_scalar_cmov(r, &secp256k1_scalar_zero, !ret);
secp256k1_scalar_cmov(s, &secp256k1_scalar_zero, !ret);
if (recid) {
const int zero = 0;
secp256k1_int_cmov(recid, &zero, !ret);
}
return ret;
}
int secp256k1_ecdsa_sign(const secp256k1_context* ctx, secp256k1_ecdsa_signature *signature, const unsigned char *msg32, const unsigned char *seckey, secp256k1_nonce_function noncefp, const void* noncedata) {
secp256k1_scalar r, s;
int ret;
VERIFY_CHECK(ctx != NULL);
ARG_CHECK(secp256k1_ecmult_gen_context_is_built(&ctx->ecmult_gen_ctx));
ARG_CHECK(msg32 != NULL);
ARG_CHECK(signature != NULL);
ARG_CHECK(seckey != NULL);
ret = secp256k1_ecdsa_sign_inner(ctx, &r, &s, NULL, msg32, seckey, noncefp, noncedata);
secp256k1_ecdsa_signature_save(signature, &r, &s);
return ret;
}