vendor libsecp256k1 so it doesn't depend on a shared library.
This commit is contained in:
fiatjaf
285
libsecp256k1/src/modules/extrakeys/main_impl.h
Normal file
285
libsecp256k1/src/modules/extrakeys/main_impl.h
Normal file
@@ -0,0 +1,285 @@
|
||||
/***********************************************************************
|
||||
* Copyright (c) 2020 Jonas Nick *
|
||||
* Distributed under the MIT software license, see the accompanying *
|
||||
* file COPYING or https://www.opensource.org/licenses/mit-license.php.*
|
||||
***********************************************************************/
|
||||
|
||||
#ifndef SECP256K1_MODULE_EXTRAKEYS_MAIN_H
|
||||
#define SECP256K1_MODULE_EXTRAKEYS_MAIN_H
|
||||
|
||||
#include "../../../include/secp256k1.h"
|
||||
#include "../../../include/secp256k1_extrakeys.h"
|
||||
#include "../../util.h"
|
||||
|
||||
static SECP256K1_INLINE int secp256k1_xonly_pubkey_load(const secp256k1_context* ctx, secp256k1_ge *ge, const secp256k1_xonly_pubkey *pubkey) {
|
||||
return secp256k1_pubkey_load(ctx, ge, (const secp256k1_pubkey *) pubkey);
|
||||
}
|
||||
|
||||
static SECP256K1_INLINE void secp256k1_xonly_pubkey_save(secp256k1_xonly_pubkey *pubkey, secp256k1_ge *ge) {
|
||||
secp256k1_pubkey_save((secp256k1_pubkey *) pubkey, ge);
|
||||
}
|
||||
|
||||
int secp256k1_xonly_pubkey_parse(const secp256k1_context* ctx, secp256k1_xonly_pubkey *pubkey, const unsigned char *input32) {
|
||||
secp256k1_ge pk;
|
||||
secp256k1_fe x;
|
||||
|
||||
VERIFY_CHECK(ctx != NULL);
|
||||
ARG_CHECK(pubkey != NULL);
|
||||
memset(pubkey, 0, sizeof(*pubkey));
|
||||
ARG_CHECK(input32 != NULL);
|
||||
|
||||
if (!secp256k1_fe_set_b32_limit(&x, input32)) {
|
||||
return 0;
|
||||
}
|
||||
if (!secp256k1_ge_set_xo_var(&pk, &x, 0)) {
|
||||
return 0;
|
||||
}
|
||||
if (!secp256k1_ge_is_in_correct_subgroup(&pk)) {
|
||||
return 0;
|
||||
}
|
||||
secp256k1_xonly_pubkey_save(pubkey, &pk);
|
||||
return 1;
|
||||
}
|
||||
|
||||
int secp256k1_xonly_pubkey_serialize(const secp256k1_context* ctx, unsigned char *output32, const secp256k1_xonly_pubkey *pubkey) {
|
||||
secp256k1_ge pk;
|
||||
|
||||
VERIFY_CHECK(ctx != NULL);
|
||||
ARG_CHECK(output32 != NULL);
|
||||
memset(output32, 0, 32);
|
||||
ARG_CHECK(pubkey != NULL);
|
||||
|
||||
if (!secp256k1_xonly_pubkey_load(ctx, &pk, pubkey)) {
|
||||
return 0;
|
||||
}
|
||||
secp256k1_fe_get_b32(output32, &pk.x);
|
||||
return 1;
|
||||
}
|
||||
|
||||
int secp256k1_xonly_pubkey_cmp(const secp256k1_context* ctx, const secp256k1_xonly_pubkey* pk0, const secp256k1_xonly_pubkey* pk1) {
|
||||
unsigned char out[2][32];
|
||||
const secp256k1_xonly_pubkey* pk[2];
|
||||
int i;
|
||||
|
||||
VERIFY_CHECK(ctx != NULL);
|
||||
pk[0] = pk0; pk[1] = pk1;
|
||||
for (i = 0; i < 2; i++) {
|
||||
/* If the public key is NULL or invalid, xonly_pubkey_serialize will
|
||||
* call the illegal_callback and return 0. In that case we will
|
||||
* serialize the key as all zeros which is less than any valid public
|
||||
* key. This results in consistent comparisons even if NULL or invalid
|
||||
* pubkeys are involved and prevents edge cases such as sorting
|
||||
* algorithms that use this function and do not terminate as a
|
||||
* result. */
|
||||
if (!secp256k1_xonly_pubkey_serialize(ctx, out[i], pk[i])) {
|
||||
/* Note that xonly_pubkey_serialize should already set the output to
|
||||
* zero in that case, but it's not guaranteed by the API, we can't
|
||||
* test it and writing a VERIFY_CHECK is more complex than
|
||||
* explicitly memsetting (again). */
|
||||
memset(out[i], 0, sizeof(out[i]));
|
||||
}
|
||||
}
|
||||
return secp256k1_memcmp_var(out[0], out[1], sizeof(out[1]));
|
||||
}
|
||||
|
||||
/** Keeps a group element as is if it has an even Y and otherwise negates it.
|
||||
* y_parity is set to 0 in the former case and to 1 in the latter case.
|
||||
* Requires that the coordinates of r are normalized. */
|
||||
static int secp256k1_extrakeys_ge_even_y(secp256k1_ge *r) {
|
||||
int y_parity = 0;
|
||||
VERIFY_CHECK(!secp256k1_ge_is_infinity(r));
|
||||
|
||||
if (secp256k1_fe_is_odd(&r->y)) {
|
||||
secp256k1_fe_negate(&r->y, &r->y, 1);
|
||||
y_parity = 1;
|
||||
}
|
||||
return y_parity;
|
||||
}
|
||||
|
||||
int secp256k1_xonly_pubkey_from_pubkey(const secp256k1_context* ctx, secp256k1_xonly_pubkey *xonly_pubkey, int *pk_parity, const secp256k1_pubkey *pubkey) {
|
||||
secp256k1_ge pk;
|
||||
int tmp;
|
||||
|
||||
VERIFY_CHECK(ctx != NULL);
|
||||
ARG_CHECK(xonly_pubkey != NULL);
|
||||
ARG_CHECK(pubkey != NULL);
|
||||
|
||||
if (!secp256k1_pubkey_load(ctx, &pk, pubkey)) {
|
||||
return 0;
|
||||
}
|
||||
tmp = secp256k1_extrakeys_ge_even_y(&pk);
|
||||
if (pk_parity != NULL) {
|
||||
*pk_parity = tmp;
|
||||
}
|
||||
secp256k1_xonly_pubkey_save(xonly_pubkey, &pk);
|
||||
return 1;
|
||||
}
|
||||
|
||||
int secp256k1_xonly_pubkey_tweak_add(const secp256k1_context* ctx, secp256k1_pubkey *output_pubkey, const secp256k1_xonly_pubkey *internal_pubkey, const unsigned char *tweak32) {
|
||||
secp256k1_ge pk;
|
||||
|
||||
VERIFY_CHECK(ctx != NULL);
|
||||
ARG_CHECK(output_pubkey != NULL);
|
||||
memset(output_pubkey, 0, sizeof(*output_pubkey));
|
||||
ARG_CHECK(internal_pubkey != NULL);
|
||||
ARG_CHECK(tweak32 != NULL);
|
||||
|
||||
if (!secp256k1_xonly_pubkey_load(ctx, &pk, internal_pubkey)
|
||||
|| !secp256k1_ec_pubkey_tweak_add_helper(&pk, tweak32)) {
|
||||
return 0;
|
||||
}
|
||||
secp256k1_pubkey_save(output_pubkey, &pk);
|
||||
return 1;
|
||||
}
|
||||
|
||||
int secp256k1_xonly_pubkey_tweak_add_check(const secp256k1_context* ctx, const unsigned char *tweaked_pubkey32, int tweaked_pk_parity, const secp256k1_xonly_pubkey *internal_pubkey, const unsigned char *tweak32) {
|
||||
secp256k1_ge pk;
|
||||
unsigned char pk_expected32[32];
|
||||
|
||||
VERIFY_CHECK(ctx != NULL);
|
||||
ARG_CHECK(internal_pubkey != NULL);
|
||||
ARG_CHECK(tweaked_pubkey32 != NULL);
|
||||
ARG_CHECK(tweak32 != NULL);
|
||||
|
||||
if (!secp256k1_xonly_pubkey_load(ctx, &pk, internal_pubkey)
|
||||
|| !secp256k1_ec_pubkey_tweak_add_helper(&pk, tweak32)) {
|
||||
return 0;
|
||||
}
|
||||
secp256k1_fe_normalize_var(&pk.x);
|
||||
secp256k1_fe_normalize_var(&pk.y);
|
||||
secp256k1_fe_get_b32(pk_expected32, &pk.x);
|
||||
|
||||
return secp256k1_memcmp_var(&pk_expected32, tweaked_pubkey32, 32) == 0
|
||||
&& secp256k1_fe_is_odd(&pk.y) == tweaked_pk_parity;
|
||||
}
|
||||
|
||||
static void secp256k1_keypair_save(secp256k1_keypair *keypair, const secp256k1_scalar *sk, secp256k1_ge *pk) {
|
||||
secp256k1_scalar_get_b32(&keypair->data[0], sk);
|
||||
secp256k1_pubkey_save((secp256k1_pubkey *)&keypair->data[32], pk);
|
||||
}
|
||||
|
||||
|
||||
static int secp256k1_keypair_seckey_load(const secp256k1_context* ctx, secp256k1_scalar *sk, const secp256k1_keypair *keypair) {
|
||||
int ret;
|
||||
|
||||
ret = secp256k1_scalar_set_b32_seckey(sk, &keypair->data[0]);
|
||||
/* We can declassify ret here because sk is only zero if a keypair function
|
||||
* failed (which zeroes the keypair) and its return value is ignored. */
|
||||
secp256k1_declassify(ctx, &ret, sizeof(ret));
|
||||
ARG_CHECK(ret);
|
||||
return ret;
|
||||
}
|
||||
|
||||
/* Load a keypair into pk and sk (if non-NULL). This function declassifies pk
|
||||
* and ARG_CHECKs that the keypair is not invalid. It always initializes sk and
|
||||
* pk with dummy values. */
|
||||
static int secp256k1_keypair_load(const secp256k1_context* ctx, secp256k1_scalar *sk, secp256k1_ge *pk, const secp256k1_keypair *keypair) {
|
||||
int ret;
|
||||
const secp256k1_pubkey *pubkey = (const secp256k1_pubkey *)&keypair->data[32];
|
||||
|
||||
/* Need to declassify the pubkey because pubkey_load ARG_CHECKs if it's
|
||||
* invalid. */
|
||||
secp256k1_declassify(ctx, pubkey, sizeof(*pubkey));
|
||||
ret = secp256k1_pubkey_load(ctx, pk, pubkey);
|
||||
if (sk != NULL) {
|
||||
ret = ret && secp256k1_keypair_seckey_load(ctx, sk, keypair);
|
||||
}
|
||||
if (!ret) {
|
||||
*pk = secp256k1_ge_const_g;
|
||||
if (sk != NULL) {
|
||||
*sk = secp256k1_scalar_one;
|
||||
}
|
||||
}
|
||||
return ret;
|
||||
}
|
||||
|
||||
int secp256k1_keypair_create(const secp256k1_context* ctx, secp256k1_keypair *keypair, const unsigned char *seckey32) {
|
||||
secp256k1_scalar sk;
|
||||
secp256k1_ge pk;
|
||||
int ret = 0;
|
||||
VERIFY_CHECK(ctx != NULL);
|
||||
ARG_CHECK(keypair != NULL);
|
||||
memset(keypair, 0, sizeof(*keypair));
|
||||
ARG_CHECK(secp256k1_ecmult_gen_context_is_built(&ctx->ecmult_gen_ctx));
|
||||
ARG_CHECK(seckey32 != NULL);
|
||||
|
||||
ret = secp256k1_ec_pubkey_create_helper(&ctx->ecmult_gen_ctx, &sk, &pk, seckey32);
|
||||
secp256k1_keypair_save(keypair, &sk, &pk);
|
||||
secp256k1_memczero(keypair, sizeof(*keypair), !ret);
|
||||
|
||||
secp256k1_scalar_clear(&sk);
|
||||
return ret;
|
||||
}
|
||||
|
||||
int secp256k1_keypair_sec(const secp256k1_context* ctx, unsigned char *seckey, const secp256k1_keypair *keypair) {
|
||||
VERIFY_CHECK(ctx != NULL);
|
||||
ARG_CHECK(seckey != NULL);
|
||||
memset(seckey, 0, 32);
|
||||
ARG_CHECK(keypair != NULL);
|
||||
|
||||
memcpy(seckey, &keypair->data[0], 32);
|
||||
return 1;
|
||||
}
|
||||
|
||||
int secp256k1_keypair_pub(const secp256k1_context* ctx, secp256k1_pubkey *pubkey, const secp256k1_keypair *keypair) {
|
||||
VERIFY_CHECK(ctx != NULL);
|
||||
ARG_CHECK(pubkey != NULL);
|
||||
memset(pubkey, 0, sizeof(*pubkey));
|
||||
ARG_CHECK(keypair != NULL);
|
||||
|
||||
memcpy(pubkey->data, &keypair->data[32], sizeof(*pubkey));
|
||||
return 1;
|
||||
}
|
||||
|
||||
int secp256k1_keypair_xonly_pub(const secp256k1_context* ctx, secp256k1_xonly_pubkey *pubkey, int *pk_parity, const secp256k1_keypair *keypair) {
|
||||
secp256k1_ge pk;
|
||||
int tmp;
|
||||
|
||||
VERIFY_CHECK(ctx != NULL);
|
||||
ARG_CHECK(pubkey != NULL);
|
||||
memset(pubkey, 0, sizeof(*pubkey));
|
||||
ARG_CHECK(keypair != NULL);
|
||||
|
||||
if (!secp256k1_keypair_load(ctx, NULL, &pk, keypair)) {
|
||||
return 0;
|
||||
}
|
||||
tmp = secp256k1_extrakeys_ge_even_y(&pk);
|
||||
if (pk_parity != NULL) {
|
||||
*pk_parity = tmp;
|
||||
}
|
||||
secp256k1_xonly_pubkey_save(pubkey, &pk);
|
||||
|
||||
return 1;
|
||||
}
|
||||
|
||||
int secp256k1_keypair_xonly_tweak_add(const secp256k1_context* ctx, secp256k1_keypair *keypair, const unsigned char *tweak32) {
|
||||
secp256k1_ge pk;
|
||||
secp256k1_scalar sk;
|
||||
int y_parity;
|
||||
int ret;
|
||||
|
||||
VERIFY_CHECK(ctx != NULL);
|
||||
ARG_CHECK(keypair != NULL);
|
||||
ARG_CHECK(tweak32 != NULL);
|
||||
|
||||
ret = secp256k1_keypair_load(ctx, &sk, &pk, keypair);
|
||||
memset(keypair, 0, sizeof(*keypair));
|
||||
|
||||
y_parity = secp256k1_extrakeys_ge_even_y(&pk);
|
||||
if (y_parity == 1) {
|
||||
secp256k1_scalar_negate(&sk, &sk);
|
||||
}
|
||||
|
||||
ret &= secp256k1_ec_seckey_tweak_add_helper(&sk, tweak32);
|
||||
ret &= secp256k1_ec_pubkey_tweak_add_helper(&pk, tweak32);
|
||||
|
||||
secp256k1_declassify(ctx, &ret, sizeof(ret));
|
||||
if (ret) {
|
||||
secp256k1_keypair_save(keypair, &sk, &pk);
|
||||
}
|
||||
|
||||
secp256k1_scalar_clear(&sk);
|
||||
return ret;
|
||||
}
|
||||
|
||||
#endif
|
||||
269
libsecp256k1/src/modules/schnorrsig/main_impl.h
Normal file
269
libsecp256k1/src/modules/schnorrsig/main_impl.h
Normal file
@@ -0,0 +1,269 @@
|
||||
/***********************************************************************
|
||||
* Copyright (c) 2018-2020 Andrew Poelstra, Jonas Nick *
|
||||
* Distributed under the MIT software license, see the accompanying *
|
||||
* file COPYING or https://www.opensource.org/licenses/mit-license.php.*
|
||||
***********************************************************************/
|
||||
|
||||
#ifndef SECP256K1_MODULE_SCHNORRSIG_MAIN_H
|
||||
#define SECP256K1_MODULE_SCHNORRSIG_MAIN_H
|
||||
|
||||
#include "../../../include/secp256k1.h"
|
||||
#include "../../../include/secp256k1_schnorrsig.h"
|
||||
#include "../../hash.h"
|
||||
|
||||
/* Initializes SHA256 with fixed midstate. This midstate was computed by applying
|
||||
* SHA256 to SHA256("BIP0340/nonce")||SHA256("BIP0340/nonce"). */
|
||||
static void secp256k1_nonce_function_bip340_sha256_tagged(secp256k1_sha256 *sha) {
|
||||
secp256k1_sha256_initialize(sha);
|
||||
sha->s[0] = 0x46615b35ul;
|
||||
sha->s[1] = 0xf4bfbff7ul;
|
||||
sha->s[2] = 0x9f8dc671ul;
|
||||
sha->s[3] = 0x83627ab3ul;
|
||||
sha->s[4] = 0x60217180ul;
|
||||
sha->s[5] = 0x57358661ul;
|
||||
sha->s[6] = 0x21a29e54ul;
|
||||
sha->s[7] = 0x68b07b4cul;
|
||||
|
||||
sha->bytes = 64;
|
||||
}
|
||||
|
||||
/* Initializes SHA256 with fixed midstate. This midstate was computed by applying
|
||||
* SHA256 to SHA256("BIP0340/aux")||SHA256("BIP0340/aux"). */
|
||||
static void secp256k1_nonce_function_bip340_sha256_tagged_aux(secp256k1_sha256 *sha) {
|
||||
secp256k1_sha256_initialize(sha);
|
||||
sha->s[0] = 0x24dd3219ul;
|
||||
sha->s[1] = 0x4eba7e70ul;
|
||||
sha->s[2] = 0xca0fabb9ul;
|
||||
sha->s[3] = 0x0fa3166dul;
|
||||
sha->s[4] = 0x3afbe4b1ul;
|
||||
sha->s[5] = 0x4c44df97ul;
|
||||
sha->s[6] = 0x4aac2739ul;
|
||||
sha->s[7] = 0x249e850aul;
|
||||
|
||||
sha->bytes = 64;
|
||||
}
|
||||
|
||||
/* algo argument for nonce_function_bip340 to derive the nonce exactly as stated in BIP-340
|
||||
* by using the correct tagged hash function. */
|
||||
static const unsigned char bip340_algo[] = {'B', 'I', 'P', '0', '3', '4', '0', '/', 'n', 'o', 'n', 'c', 'e'};
|
||||
|
||||
static const unsigned char schnorrsig_extraparams_magic[4] = SECP256K1_SCHNORRSIG_EXTRAPARAMS_MAGIC;
|
||||
|
||||
static int nonce_function_bip340(unsigned char *nonce32, const unsigned char *msg, size_t msglen, const unsigned char *key32, const unsigned char *xonly_pk32, const unsigned char *algo, size_t algolen, void *data) {
|
||||
secp256k1_sha256 sha;
|
||||
unsigned char masked_key[32];
|
||||
int i;
|
||||
|
||||
if (algo == NULL) {
|
||||
return 0;
|
||||
}
|
||||
|
||||
if (data != NULL) {
|
||||
secp256k1_nonce_function_bip340_sha256_tagged_aux(&sha);
|
||||
secp256k1_sha256_write(&sha, data, 32);
|
||||
secp256k1_sha256_finalize(&sha, masked_key);
|
||||
for (i = 0; i < 32; i++) {
|
||||
masked_key[i] ^= key32[i];
|
||||
}
|
||||
} else {
|
||||
/* Precomputed TaggedHash("BIP0340/aux", 0x0000...00); */
|
||||
static const unsigned char ZERO_MASK[32] = {
|
||||
84, 241, 105, 207, 201, 226, 229, 114,
|
||||
116, 128, 68, 31, 144, 186, 37, 196,
|
||||
136, 244, 97, 199, 11, 94, 165, 220,
|
||||
170, 247, 175, 105, 39, 10, 165, 20
|
||||
};
|
||||
for (i = 0; i < 32; i++) {
|
||||
masked_key[i] = key32[i] ^ ZERO_MASK[i];
|
||||
}
|
||||
}
|
||||
|
||||
/* Tag the hash with algo which is important to avoid nonce reuse across
|
||||
* algorithms. If this nonce function is used in BIP-340 signing as defined
|
||||
* in the spec, an optimized tagging implementation is used. */
|
||||
if (algolen == sizeof(bip340_algo)
|
||||
&& secp256k1_memcmp_var(algo, bip340_algo, algolen) == 0) {
|
||||
secp256k1_nonce_function_bip340_sha256_tagged(&sha);
|
||||
} else {
|
||||
secp256k1_sha256_initialize_tagged(&sha, algo, algolen);
|
||||
}
|
||||
|
||||
/* Hash masked-key||pk||msg using the tagged hash as per the spec */
|
||||
secp256k1_sha256_write(&sha, masked_key, 32);
|
||||
secp256k1_sha256_write(&sha, xonly_pk32, 32);
|
||||
secp256k1_sha256_write(&sha, msg, msglen);
|
||||
secp256k1_sha256_finalize(&sha, nonce32);
|
||||
secp256k1_sha256_clear(&sha);
|
||||
return 1;
|
||||
}
|
||||
|
||||
const secp256k1_nonce_function_hardened secp256k1_nonce_function_bip340 = nonce_function_bip340;
|
||||
|
||||
/* Initializes SHA256 with fixed midstate. This midstate was computed by applying
|
||||
* SHA256 to SHA256("BIP0340/challenge")||SHA256("BIP0340/challenge"). */
|
||||
static void secp256k1_schnorrsig_sha256_tagged(secp256k1_sha256 *sha) {
|
||||
secp256k1_sha256_initialize(sha);
|
||||
sha->s[0] = 0x9cecba11ul;
|
||||
sha->s[1] = 0x23925381ul;
|
||||
sha->s[2] = 0x11679112ul;
|
||||
sha->s[3] = 0xd1627e0ful;
|
||||
sha->s[4] = 0x97c87550ul;
|
||||
sha->s[5] = 0x003cc765ul;
|
||||
sha->s[6] = 0x90f61164ul;
|
||||
sha->s[7] = 0x33e9b66aul;
|
||||
sha->bytes = 64;
|
||||
}
|
||||
|
||||
static void secp256k1_schnorrsig_challenge(secp256k1_scalar* e, const unsigned char *r32, const unsigned char *msg, size_t msglen, const unsigned char *pubkey32)
|
||||
{
|
||||
unsigned char buf[32];
|
||||
secp256k1_sha256 sha;
|
||||
|
||||
/* tagged hash(r.x, pk.x, msg) */
|
||||
secp256k1_schnorrsig_sha256_tagged(&sha);
|
||||
secp256k1_sha256_write(&sha, r32, 32);
|
||||
secp256k1_sha256_write(&sha, pubkey32, 32);
|
||||
secp256k1_sha256_write(&sha, msg, msglen);
|
||||
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);
|
||||
}
|
||||
|
||||
static int secp256k1_schnorrsig_sign_internal(const secp256k1_context* ctx, unsigned char *sig64, const unsigned char *msg, size_t msglen, const secp256k1_keypair *keypair, secp256k1_nonce_function_hardened noncefp, void *ndata) {
|
||||
secp256k1_scalar sk;
|
||||
secp256k1_scalar e;
|
||||
secp256k1_scalar k;
|
||||
secp256k1_gej rj;
|
||||
secp256k1_ge pk;
|
||||
secp256k1_ge r;
|
||||
unsigned char buf[32] = { 0 };
|
||||
unsigned char pk_buf[32];
|
||||
unsigned char seckey[32];
|
||||
int ret = 1;
|
||||
|
||||
VERIFY_CHECK(ctx != NULL);
|
||||
ARG_CHECK(secp256k1_ecmult_gen_context_is_built(&ctx->ecmult_gen_ctx));
|
||||
ARG_CHECK(sig64 != NULL);
|
||||
ARG_CHECK(msg != NULL || msglen == 0);
|
||||
ARG_CHECK(keypair != NULL);
|
||||
|
||||
if (noncefp == NULL) {
|
||||
noncefp = secp256k1_nonce_function_bip340;
|
||||
}
|
||||
|
||||
ret &= secp256k1_keypair_load(ctx, &sk, &pk, keypair);
|
||||
/* Because we are signing for a x-only pubkey, the secret key is negated
|
||||
* before signing if the point corresponding to the secret key does not
|
||||
* have an even Y. */
|
||||
if (secp256k1_fe_is_odd(&pk.y)) {
|
||||
secp256k1_scalar_negate(&sk, &sk);
|
||||
}
|
||||
|
||||
secp256k1_scalar_get_b32(seckey, &sk);
|
||||
secp256k1_fe_get_b32(pk_buf, &pk.x);
|
||||
ret &= !!noncefp(buf, msg, msglen, seckey, pk_buf, bip340_algo, sizeof(bip340_algo), ndata);
|
||||
secp256k1_scalar_set_b32(&k, buf, NULL);
|
||||
ret &= !secp256k1_scalar_is_zero(&k);
|
||||
secp256k1_scalar_cmov(&k, &secp256k1_scalar_one, !ret);
|
||||
|
||||
secp256k1_ecmult_gen(&ctx->ecmult_gen_ctx, &rj, &k);
|
||||
secp256k1_ge_set_gej(&r, &rj);
|
||||
|
||||
/* We declassify r to allow using it as a branch point. This is fine
|
||||
* because r is not a secret. */
|
||||
secp256k1_declassify(ctx, &r, sizeof(r));
|
||||
secp256k1_fe_normalize_var(&r.y);
|
||||
if (secp256k1_fe_is_odd(&r.y)) {
|
||||
secp256k1_scalar_negate(&k, &k);
|
||||
}
|
||||
secp256k1_fe_normalize_var(&r.x);
|
||||
secp256k1_fe_get_b32(&sig64[0], &r.x);
|
||||
|
||||
secp256k1_schnorrsig_challenge(&e, &sig64[0], msg, msglen, pk_buf);
|
||||
secp256k1_scalar_mul(&e, &e, &sk);
|
||||
secp256k1_scalar_add(&e, &e, &k);
|
||||
secp256k1_scalar_get_b32(&sig64[32], &e);
|
||||
|
||||
secp256k1_memczero(sig64, 64, !ret);
|
||||
secp256k1_scalar_clear(&k);
|
||||
secp256k1_scalar_clear(&sk);
|
||||
secp256k1_memclear(seckey, sizeof(seckey));
|
||||
secp256k1_gej_clear(&rj);
|
||||
|
||||
return ret;
|
||||
}
|
||||
|
||||
int secp256k1_schnorrsig_sign32(const secp256k1_context* ctx, unsigned char *sig64, const unsigned char *msg32, const secp256k1_keypair *keypair, const unsigned char *aux_rand32) {
|
||||
/* We cast away const from the passed aux_rand32 argument since we know the default nonce function does not modify it. */
|
||||
return secp256k1_schnorrsig_sign_internal(ctx, sig64, msg32, 32, keypair, secp256k1_nonce_function_bip340, (unsigned char*)aux_rand32);
|
||||
}
|
||||
|
||||
int secp256k1_schnorrsig_sign(const secp256k1_context* ctx, unsigned char *sig64, const unsigned char *msg32, const secp256k1_keypair *keypair, const unsigned char *aux_rand32) {
|
||||
return secp256k1_schnorrsig_sign32(ctx, sig64, msg32, keypair, aux_rand32);
|
||||
}
|
||||
|
||||
int secp256k1_schnorrsig_sign_custom(const secp256k1_context* ctx, unsigned char *sig64, const unsigned char *msg, size_t msglen, const secp256k1_keypair *keypair, secp256k1_schnorrsig_extraparams *extraparams) {
|
||||
secp256k1_nonce_function_hardened noncefp = NULL;
|
||||
void *ndata = NULL;
|
||||
VERIFY_CHECK(ctx != NULL);
|
||||
|
||||
if (extraparams != NULL) {
|
||||
ARG_CHECK(secp256k1_memcmp_var(extraparams->magic,
|
||||
schnorrsig_extraparams_magic,
|
||||
sizeof(extraparams->magic)) == 0);
|
||||
noncefp = extraparams->noncefp;
|
||||
ndata = extraparams->ndata;
|
||||
}
|
||||
return secp256k1_schnorrsig_sign_internal(ctx, sig64, msg, msglen, keypair, noncefp, ndata);
|
||||
}
|
||||
|
||||
int secp256k1_schnorrsig_verify(const secp256k1_context* ctx, const unsigned char *sig64, const unsigned char *msg, size_t msglen, const secp256k1_xonly_pubkey *pubkey) {
|
||||
secp256k1_scalar s;
|
||||
secp256k1_scalar e;
|
||||
secp256k1_gej rj;
|
||||
secp256k1_ge pk;
|
||||
secp256k1_gej pkj;
|
||||
secp256k1_fe rx;
|
||||
secp256k1_ge r;
|
||||
unsigned char buf[32];
|
||||
int overflow;
|
||||
|
||||
VERIFY_CHECK(ctx != NULL);
|
||||
ARG_CHECK(sig64 != NULL);
|
||||
ARG_CHECK(msg != NULL || msglen == 0);
|
||||
ARG_CHECK(pubkey != NULL);
|
||||
|
||||
if (!secp256k1_fe_set_b32_limit(&rx, &sig64[0])) {
|
||||
return 0;
|
||||
}
|
||||
|
||||
secp256k1_scalar_set_b32(&s, &sig64[32], &overflow);
|
||||
if (overflow) {
|
||||
return 0;
|
||||
}
|
||||
|
||||
if (!secp256k1_xonly_pubkey_load(ctx, &pk, pubkey)) {
|
||||
return 0;
|
||||
}
|
||||
|
||||
/* Compute e. */
|
||||
secp256k1_fe_get_b32(buf, &pk.x);
|
||||
secp256k1_schnorrsig_challenge(&e, &sig64[0], msg, msglen, buf);
|
||||
|
||||
/* Compute rj = s*G + (-e)*pkj */
|
||||
secp256k1_scalar_negate(&e, &e);
|
||||
secp256k1_gej_set_ge(&pkj, &pk);
|
||||
secp256k1_ecmult(&rj, &pkj, &e, &s);
|
||||
|
||||
secp256k1_ge_set_gej_var(&r, &rj);
|
||||
if (secp256k1_ge_is_infinity(&r)) {
|
||||
return 0;
|
||||
}
|
||||
|
||||
secp256k1_fe_normalize_var(&r.y);
|
||||
return !secp256k1_fe_is_odd(&r.y) &&
|
||||
secp256k1_fe_equal(&rx, &r.x);
|
||||
}
|
||||
|
||||
#endif
|
||||
Reference in New Issue
Block a user