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Differential D7666 Diff 24027 src/secp256k1/src/modules/schnorrsig/main_impl.h

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src/secp256k1/src/modules/schnorrsig/main_impl.h

Show First 20 Lines • Show All 102 Lines • ▼ Show 20 Linesstatic void secp256k1_schnorrsig_sha256_tagged(secp256k1_sha256 *sha) {
sha->s[3] = 0xd1627e0ful; sha->s[3] = 0xd1627e0ful;
sha->s[4] = 0x97c87550ul; sha->s[4] = 0x97c87550ul;
sha->s[5] = 0x003cc765ul; sha->s[5] = 0x003cc765ul;
sha->s[6] = 0x90f61164ul; sha->s[6] = 0x90f61164ul;
sha->s[7] = 0x33e9b66aul; sha->s[7] = 0x33e9b66aul;
sha->bytes = 64; sha->bytes = 64;
} }
static void secp256k1_schnorrsig_challenge(secp256k1_scalar* e, const unsigned char *r32, const unsigned char *msg32, const unsigned char *pubkey32)
{
unsigned char buf[32];
secp256k1_sha256 sha;
/* tagged hash(r.x, pk.x, msg32) */
secp256k1_schnorrsig_sha256_tagged(&sha);
secp256k1_sha256_write(&sha, r32, 32);
secp256k1_sha256_write(&sha, pubkey32, 32);
secp256k1_sha256_write(&sha, msg32, 32);
secp256k1_sha256_finalize(&sha, buf);
/* Set scalar e to the challenge hash modulo the curve order as per
* BIP340. */
secp256k1_scalar_set_b32(e, buf, NULL);
}
int secp256k1_schnorrsig_sign(const secp256k1_context* ctx, unsigned char *sig64, const unsigned char *msg32, const secp256k1_keypair *keypair, secp256k1_nonce_function_hardened noncefp, void *ndata) { int secp256k1_schnorrsig_sign(const secp256k1_context* ctx, unsigned char *sig64, const unsigned char *msg32, const secp256k1_keypair *keypair, secp256k1_nonce_function_hardened noncefp, void *ndata) {
secp256k1_scalar sk; secp256k1_scalar sk;
secp256k1_scalar e; secp256k1_scalar e;
secp256k1_scalar k; secp256k1_scalar k;
secp256k1_gej rj; secp256k1_gej rj;
secp256k1_ge pk; secp256k1_ge pk;
secp256k1_ge r; secp256k1_ge r;
secp256k1_sha256 sha;
unsigned char buf[32] = { 0 }; unsigned char buf[32] = { 0 };
unsigned char pk_buf[32]; unsigned char pk_buf[32];
unsigned char seckey[32]; unsigned char seckey[32];
int ret = 1; int ret = 1;
VERIFY_CHECK(ctx != NULL); VERIFY_CHECK(ctx != NULL);
ARG_CHECK(secp256k1_ecmult_gen_context_is_built(&ctx->ecmult_gen_ctx)); ARG_CHECK(secp256k1_ecmult_gen_context_is_built(&ctx->ecmult_gen_ctx));
ARG_CHECK(sig64 != NULL); ARG_CHECK(sig64 != NULL);
Show All 27 Linesint secp256k1_schnorrsig_sign(const secp256k1_context* ctx, unsigned char *sig64, const unsigned char *msg32, const secp256k1_keypair *keypair, secp256k1_nonce_function_hardened noncefp, void *ndata) {
secp256k1_declassify(ctx, &r, sizeof(r)); secp256k1_declassify(ctx, &r, sizeof(r));
secp256k1_fe_normalize_var(&r.y); secp256k1_fe_normalize_var(&r.y);
if (secp256k1_fe_is_odd(&r.y)) { if (secp256k1_fe_is_odd(&r.y)) {
secp256k1_scalar_negate(&k, &k); secp256k1_scalar_negate(&k, &k);
} }
secp256k1_fe_normalize_var(&r.x); secp256k1_fe_normalize_var(&r.x);
secp256k1_fe_get_b32(&sig64[0], &r.x); secp256k1_fe_get_b32(&sig64[0], &r.x);
/* tagged hash(r.x, pk.x, msg32) */ secp256k1_schnorrsig_challenge(&e, &sig64[0], msg32, pk_buf);
secp256k1_schnorrsig_sha256_tagged(&sha);
secp256k1_sha256_write(&sha, &sig64[0], 32);
secp256k1_sha256_write(&sha, pk_buf, sizeof(pk_buf));
secp256k1_sha256_write(&sha, msg32, 32);
secp256k1_sha256_finalize(&sha, buf);
/* Set scalar e to the challenge hash modulo the curve order as per
* BIP340. */
secp256k1_scalar_set_b32(&e, buf, NULL);
secp256k1_scalar_mul(&e, &e, &sk); secp256k1_scalar_mul(&e, &e, &sk);
secp256k1_scalar_add(&e, &e, &k); secp256k1_scalar_add(&e, &e, &k);
secp256k1_scalar_get_b32(&sig64[32], &e); secp256k1_scalar_get_b32(&sig64[32], &e);
memczero(sig64, 64, !ret); memczero(sig64, 64, !ret);
secp256k1_scalar_clear(&k); secp256k1_scalar_clear(&k);
secp256k1_scalar_clear(&sk); secp256k1_scalar_clear(&sk);
memset(seckey, 0, sizeof(seckey)); memset(seckey, 0, sizeof(seckey));
return ret; return ret;
} }
int secp256k1_schnorrsig_verify(const secp256k1_context* ctx, const unsigned char *sig64, const unsigned char *msg32, const secp256k1_xonly_pubkey *pubkey) { int secp256k1_schnorrsig_verify(const secp256k1_context* ctx, const unsigned char *sig64, const unsigned char *msg32, const secp256k1_xonly_pubkey *pubkey) {
secp256k1_scalar s; secp256k1_scalar s;
secp256k1_scalar e; secp256k1_scalar e;
secp256k1_gej rj; secp256k1_gej rj;
secp256k1_ge pk; secp256k1_ge pk;
secp256k1_gej pkj; secp256k1_gej pkj;
secp256k1_fe rx; secp256k1_fe rx;
secp256k1_ge r; secp256k1_ge r;
secp256k1_sha256 sha;
unsigned char buf[32]; unsigned char buf[32];
int overflow; int overflow;
VERIFY_CHECK(ctx != NULL); VERIFY_CHECK(ctx != NULL);
ARG_CHECK(secp256k1_ecmult_context_is_built(&ctx->ecmult_ctx)); ARG_CHECK(secp256k1_ecmult_context_is_built(&ctx->ecmult_ctx));
ARG_CHECK(sig64 != NULL); ARG_CHECK(sig64 != NULL);
ARG_CHECK(msg32 != NULL); ARG_CHECK(msg32 != NULL);
ARG_CHECK(pubkey != NULL); ARG_CHECK(pubkey != NULL);
if (!secp256k1_fe_set_b32(&rx, &sig64[0])) { if (!secp256k1_fe_set_b32(&rx, &sig64[0])) {
return 0; return 0;
} }
secp256k1_scalar_set_b32(&s, &sig64[32], &overflow); secp256k1_scalar_set_b32(&s, &sig64[32], &overflow);
if (overflow) { if (overflow) {
return 0; return 0;
} }
if (!secp256k1_xonly_pubkey_load(ctx, &pk, pubkey)) { if (!secp256k1_xonly_pubkey_load(ctx, &pk, pubkey)) {
return 0; return 0;
} }
secp256k1_schnorrsig_sha256_tagged(&sha); /* Compute e. */
secp256k1_sha256_write(&sha, &sig64[0], 32);
secp256k1_fe_get_b32(buf, &pk.x); secp256k1_fe_get_b32(buf, &pk.x);
secp256k1_sha256_write(&sha, buf, sizeof(buf)); secp256k1_schnorrsig_challenge(&e, &sig64[0], msg32, buf);
secp256k1_sha256_write(&sha, msg32, 32);
secp256k1_sha256_finalize(&sha, buf);
secp256k1_scalar_set_b32(&e, buf, NULL);
/* Compute rj = s*G + (-e)*pkj */ /* Compute rj = s*G + (-e)*pkj */
secp256k1_scalar_negate(&e, &e); secp256k1_scalar_negate(&e, &e);
secp256k1_gej_set_ge(&pkj, &pk); secp256k1_gej_set_ge(&pkj, &pk);
secp256k1_ecmult(&ctx->ecmult_ctx, &rj, &pkj, &e, &s); secp256k1_ecmult(&ctx->ecmult_ctx, &rj, &pkj, &e, &s);
secp256k1_ge_set_gej_var(&r, &rj); secp256k1_ge_set_gej_var(&r, &rj);
if (secp256k1_ge_is_infinity(&r)) { if (secp256k1_ge_is_infinity(&r)) {
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