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bitcoin/src/secp256k1/src/secp256k1.c

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/***********************************************************************
* Copyright (c) 2013-2015 Pieter Wuille *
* Distributed under the MIT software license, see the accompanying *
* file COPYING or https://www.opensource.org/licenses/mit-license.php.*
***********************************************************************/
/* This is a C project. It should not be compiled with a C++ compiler,
* and we error out if we detect one.
*
* We still want to be able to test the project with a C++ compiler
* because it is still good to know if this will lead to real trouble, so
* there is a possibility to override the check. But be warned that
* compiling with a C++ compiler is not supported. */
#if defined(__cplusplus) && !defined(SECP256K1_CPLUSPLUS_TEST_OVERRIDE)
#error Trying to compile a C project with a C++ compiler.
#endif
#define SECP256K1_BUILD
#include "../include/secp256k1.h"
#include "../include/secp256k1_preallocated.h"
#include "assumptions.h"
#include "util.h"
#include "field_impl.h"
#include "scalar_impl.h"
#include "group_impl.h"
#include "ecmult_impl.h"
#include "ecmult_const_impl.h"
#include "ecmult_gen_impl.h"
#include "ecdsa_impl.h"
#include "eckey_impl.h"
#include "hash_impl.h"
#include "int128_impl.h"
#include "scratch_impl.h"
#include "selftest.h"
#ifdef SECP256K1_NO_BUILD
# error "secp256k1.h processed without SECP256K1_BUILD defined while building secp256k1.c"
#endif
#if defined(VALGRIND)
# include <valgrind/memcheck.h>
#endif
#define ARG_CHECK(cond) do { \
if (EXPECT(!(cond), 0)) { \
secp256k1_callback_call(&ctx->illegal_callback, #cond); \
return 0; \
} \
} while(0)
#define ARG_CHECK_NO_RETURN(cond) do { \
if (EXPECT(!(cond), 0)) { \
secp256k1_callback_call(&ctx->illegal_callback, #cond); \
} \
} while(0)
/* Note that whenever you change the context struct, you must also change the
* context_eq function. */
struct secp256k1_context_struct {
secp256k1_ecmult_gen_context ecmult_gen_ctx;
secp256k1_callback illegal_callback;
secp256k1_callback error_callback;
int declassify;
};
static const secp256k1_context secp256k1_context_static_ = {
{ 0 },
{ secp256k1_default_illegal_callback_fn, 0 },
{ secp256k1_default_error_callback_fn, 0 },
0
};
const secp256k1_context *secp256k1_context_static = &secp256k1_context_static_;
const secp256k1_context *secp256k1_context_no_precomp = &secp256k1_context_static_;
void secp256k1_selftest(void) {
if (!secp256k1_selftest_passes()) {
secp256k1_callback_call(&default_error_callback, "self test failed");
}
}
size_t secp256k1_context_preallocated_size(unsigned int flags) {
size_t ret = sizeof(secp256k1_context);
/* A return value of 0 is reserved as an indicator for errors when we call this function internally. */
VERIFY_CHECK(ret != 0);
if (EXPECT((flags & SECP256K1_FLAGS_TYPE_MASK) != SECP256K1_FLAGS_TYPE_CONTEXT, 0)) {
secp256k1_callback_call(&default_illegal_callback,
"Invalid flags");
return 0;
}
return ret;
}
size_t secp256k1_context_preallocated_clone_size(const secp256k1_context* ctx) {
size_t ret = sizeof(secp256k1_context);
VERIFY_CHECK(ctx != NULL);
return ret;
}
secp256k1_context* secp256k1_context_preallocated_create(void* prealloc, unsigned int flags) {
size_t prealloc_size;
secp256k1_context* ret;
secp256k1_selftest();
prealloc_size = secp256k1_context_preallocated_size(flags);
if (prealloc_size == 0) {
return NULL;
}
VERIFY_CHECK(prealloc != NULL);
ret = (secp256k1_context*)prealloc;
ret->illegal_callback = default_illegal_callback;
ret->error_callback = default_error_callback;
/* Flags have been checked by secp256k1_context_preallocated_size. */
VERIFY_CHECK((flags & SECP256K1_FLAGS_TYPE_MASK) == SECP256K1_FLAGS_TYPE_CONTEXT);
secp256k1_ecmult_gen_context_build(&ret->ecmult_gen_ctx);
ret->declassify = !!(flags & SECP256K1_FLAGS_BIT_CONTEXT_DECLASSIFY);
return ret;
}
secp256k1_context* secp256k1_context_create(unsigned int flags) {
size_t const prealloc_size = secp256k1_context_preallocated_size(flags);
secp256k1_context* ctx = (secp256k1_context*)checked_malloc(&default_error_callback, prealloc_size);
if (EXPECT(secp256k1_context_preallocated_create(ctx, flags) == NULL, 0)) {
free(ctx);
return NULL;
}
return ctx;
}
secp256k1_context* secp256k1_context_preallocated_clone(const secp256k1_context* ctx, void* prealloc) {
secp256k1_context* ret;
VERIFY_CHECK(ctx != NULL);
ARG_CHECK(prealloc != NULL);
ret = (secp256k1_context*)prealloc;
*ret = *ctx;
return ret;
}
secp256k1_context* secp256k1_context_clone(const secp256k1_context* ctx) {
secp256k1_context* ret;
size_t prealloc_size;
VERIFY_CHECK(ctx != NULL);
prealloc_size = secp256k1_context_preallocated_clone_size(ctx);
ret = (secp256k1_context*)checked_malloc(&ctx->error_callback, prealloc_size);
ret = secp256k1_context_preallocated_clone(ctx, ret);
return ret;
}
void secp256k1_context_preallocated_destroy(secp256k1_context* ctx) {
ARG_CHECK_NO_RETURN(ctx != secp256k1_context_static);
if (ctx != NULL) {
secp256k1_ecmult_gen_context_clear(&ctx->ecmult_gen_ctx);
}
}
void secp256k1_context_destroy(secp256k1_context* ctx) {
if (ctx != NULL) {
secp256k1_context_preallocated_destroy(ctx);
free(ctx);
}
}
void secp256k1_context_set_illegal_callback(secp256k1_context* ctx, void (*fun)(const char* message, void* data), const void* data) {
ARG_CHECK_NO_RETURN(ctx != secp256k1_context_static);
if (fun == NULL) {
fun = secp256k1_default_illegal_callback_fn;
}
ctx->illegal_callback.fn = fun;
ctx->illegal_callback.data = data;
}
void secp256k1_context_set_error_callback(secp256k1_context* ctx, void (*fun)(const char* message, void* data), const void* data) {
ARG_CHECK_NO_RETURN(ctx != secp256k1_context_static);
if (fun == NULL) {
fun = secp256k1_default_error_callback_fn;
}
ctx->error_callback.fn = fun;
ctx->error_callback.data = data;
}
secp256k1_scratch_space* secp256k1_scratch_space_create(const secp256k1_context* ctx, size_t max_size) {
VERIFY_CHECK(ctx != NULL);
return secp256k1_scratch_create(&ctx->error_callback, max_size);
}
void secp256k1_scratch_space_destroy(const secp256k1_context *ctx, secp256k1_scratch_space* scratch) {
VERIFY_CHECK(ctx != NULL);
secp256k1_scratch_destroy(&ctx->error_callback, scratch);
}
/* Mark memory as no-longer-secret for the purpose of analysing constant-time behaviour
* of the software. This is setup for use with valgrind but could be substituted with
* the appropriate instrumentation for other analysis tools.
*/
static SECP256K1_INLINE void secp256k1_declassify(const secp256k1_context* ctx, const void *p, size_t len) {
#if defined(VALGRIND)
if (EXPECT(ctx->declassify,0)) VALGRIND_MAKE_MEM_DEFINED(p, len);
#else
(void)ctx;
(void)p;
(void)len;
#endif
}
static int secp256k1_pubkey_load(const secp256k1_context* ctx, secp256k1_ge* ge, const secp256k1_pubkey* pubkey) {
if (sizeof(secp256k1_ge_storage) == 64) {
/* When the secp256k1_ge_storage type is exactly 64 byte, use its
* representation inside secp256k1_pubkey, as conversion is very fast.
* Note that secp256k1_pubkey_save must use the same representation. */
secp256k1_ge_storage s;
memcpy(&s, &pubkey->data[0], sizeof(s));
secp256k1_ge_from_storage(ge, &s);
} else {
/* Otherwise, fall back to 32-byte big endian for X and Y. */
secp256k1_fe x, y;
secp256k1_fe_set_b32(&x, pubkey->data);
secp256k1_fe_set_b32(&y, pubkey->data + 32);
secp256k1_ge_set_xy(ge, &x, &y);
}
ARG_CHECK(!secp256k1_fe_is_zero(&ge->x));
return 1;
}
static void secp256k1_pubkey_save(secp256k1_pubkey* pubkey, secp256k1_ge* ge) {
if (sizeof(secp256k1_ge_storage) == 64) {
secp256k1_ge_storage s;
secp256k1_ge_to_storage(&s, ge);
memcpy(&pubkey->data[0], &s, sizeof(s));
} else {
VERIFY_CHECK(!secp256k1_ge_is_infinity(ge));
secp256k1_fe_normalize_var(&ge->x);
secp256k1_fe_normalize_var(&ge->y);
secp256k1_fe_get_b32(pubkey->data, &ge->x);
secp256k1_fe_get_b32(pubkey->data + 32, &ge->y);
}
}
int secp256k1_ec_pubkey_parse(const secp256k1_context* ctx, secp256k1_pubkey* pubkey, const unsigned char *input, size_t inputlen) {
secp256k1_ge Q;
VERIFY_CHECK(ctx != NULL);
ARG_CHECK(pubkey != NULL);
memset(pubkey, 0, sizeof(*pubkey));
ARG_CHECK(input != NULL);
if (!secp256k1_eckey_pubkey_parse(&Q, input, inputlen)) {
return 0;
}
if (!secp256k1_ge_is_in_correct_subgroup(&Q)) {
return 0;
}
secp256k1_pubkey_save(pubkey, &Q);
secp256k1_ge_clear(&Q);
return 1;
}
int secp256k1_ec_pubkey_serialize(const secp256k1_context* ctx, unsigned char *output, size_t *outputlen, const secp256k1_pubkey* pubkey, unsigned int flags) {
secp256k1_ge Q;
size_t len;
int ret = 0;
VERIFY_CHECK(ctx != NULL);
ARG_CHECK(outputlen != NULL);
ARG_CHECK(*outputlen >= ((flags & SECP256K1_FLAGS_BIT_COMPRESSION) ? 33u : 65u));
len = *outputlen;
*outputlen = 0;
ARG_CHECK(output != NULL);
memset(output, 0, len);
ARG_CHECK(pubkey != NULL);
ARG_CHECK((flags & SECP256K1_FLAGS_TYPE_MASK) == SECP256K1_FLAGS_TYPE_COMPRESSION);
if (secp256k1_pubkey_load(ctx, &Q, pubkey)) {
ret = secp256k1_eckey_pubkey_serialize(&Q, output, &len, flags & SECP256K1_FLAGS_BIT_COMPRESSION);
if (ret) {
*outputlen = len;
}
}
return ret;
}
int secp256k1_ec_pubkey_cmp(const secp256k1_context* ctx, const secp256k1_pubkey* pubkey0, const secp256k1_pubkey* pubkey1) {
unsigned char out[2][33];
const secp256k1_pubkey* pk[2];
int i;
VERIFY_CHECK(ctx != NULL);
pk[0] = pubkey0; pk[1] = pubkey1;
for (i = 0; i < 2; i++) {
size_t out_size = sizeof(out[i]);
/* If the public key is NULL or invalid, ec_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_ec_pubkey_serialize(ctx, out[i], &out_size, pk[i], SECP256K1_EC_COMPRESSED)) {
/* Note that ec_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[0]));
}
static void secp256k1_ecdsa_signature_load(const secp256k1_context* ctx, secp256k1_scalar* r, secp256k1_scalar* s, const secp256k1_ecdsa_signature* sig) {
(void)ctx;
if (sizeof(secp256k1_scalar) == 32) {
/* When the secp256k1_scalar type is exactly 32 byte, use its
* representation inside secp256k1_ecdsa_signature, as conversion is very fast.
* Note that secp256k1_ecdsa_signature_save must use the same representation. */
memcpy(r, &sig->data[0], 32);
memcpy(s, &sig->data[32], 32);
} else {
secp256k1_scalar_set_b32(r, &sig->data[0], NULL);
secp256k1_scalar_set_b32(s, &sig->data[32], NULL);
}
}
static void secp256k1_ecdsa_signature_save(secp256k1_ecdsa_signature* sig, const secp256k1_scalar* r, const secp256k1_scalar* s) {
if (sizeof(secp256k1_scalar) == 32) {
memcpy(&sig->data[0], r, 32);
memcpy(&sig->data[32], s, 32);
} else {
secp256k1_scalar_get_b32(&sig->data[0], r);
secp256k1_scalar_get_b32(&sig->data[32], s);
}
}
int secp256k1_ecdsa_signature_parse_der(const secp256k1_context* ctx, secp256k1_ecdsa_signature* sig, const unsigned char *input, size_t inputlen) {
secp256k1_scalar r, s;
VERIFY_CHECK(ctx != NULL);
ARG_CHECK(sig != NULL);
ARG_CHECK(input != NULL);
if (secp256k1_ecdsa_sig_parse(&r, &s, input, inputlen)) {
secp256k1_ecdsa_signature_save(sig, &r, &s);
return 1;
} else {
memset(sig, 0, sizeof(*sig));
return 0;
}
}
int secp256k1_ecdsa_signature_parse_compact(const secp256k1_context* ctx, secp256k1_ecdsa_signature* sig, const unsigned char *input64) {
secp256k1_scalar r, s;
int ret = 1;
int overflow = 0;
VERIFY_CHECK(ctx != NULL);
ARG_CHECK(sig != NULL);
ARG_CHECK(input64 != NULL);
secp256k1_scalar_set_b32(&r, &input64[0], &overflow);
ret &= !overflow;
secp256k1_scalar_set_b32(&s, &input64[32], &overflow);
ret &= !overflow;
if (ret) {
secp256k1_ecdsa_signature_save(sig, &r, &s);
} else {
memset(sig, 0, sizeof(*sig));
}
return ret;
}
int secp256k1_ecdsa_signature_serialize_der(const secp256k1_context* ctx, unsigned char *output, size_t *outputlen, const secp256k1_ecdsa_signature* sig) {
secp256k1_scalar r, s;
VERIFY_CHECK(ctx != NULL);
ARG_CHECK(output != NULL);
ARG_CHECK(outputlen != NULL);
ARG_CHECK(sig != NULL);
secp256k1_ecdsa_signature_load(ctx, &r, &s, sig);
return secp256k1_ecdsa_sig_serialize(output, outputlen, &r, &s);
}
int secp256k1_ecdsa_signature_serialize_compact(const secp256k1_context* ctx, unsigned char *output64, const secp256k1_ecdsa_signature* sig) {
secp256k1_scalar r, s;
VERIFY_CHECK(ctx != NULL);
ARG_CHECK(output64 != NULL);
ARG_CHECK(sig != NULL);
secp256k1_ecdsa_signature_load(ctx, &r, &s, sig);
secp256k1_scalar_get_b32(&output64[0], &r);
secp256k1_scalar_get_b32(&output64[32], &s);
return 1;
}
int secp256k1_ecdsa_signature_normalize(const secp256k1_context* ctx, secp256k1_ecdsa_signature *sigout, const secp256k1_ecdsa_signature *sigin) {
secp256k1_scalar r, s;
int ret = 0;
VERIFY_CHECK(ctx != NULL);
ARG_CHECK(sigin != NULL);
secp256k1_ecdsa_signature_load(ctx, &r, &s, sigin);
ret = secp256k1_scalar_is_high(&s);
if (sigout != NULL) {
if (ret) {
secp256k1_scalar_negate(&s, &s);
}
secp256k1_ecdsa_signature_save(sigout, &r, &s);
}
return ret;
}
int secp256k1_ecdsa_verify(const secp256k1_context* ctx, const secp256k1_ecdsa_signature *sig, const unsigned char *msghash32, const secp256k1_pubkey *pubkey) {
secp256k1_ge q;
secp256k1_scalar r, s;
secp256k1_scalar m;
VERIFY_CHECK(ctx != NULL);
ARG_CHECK(msghash32 != NULL);
ARG_CHECK(sig != NULL);
ARG_CHECK(pubkey != NULL);
secp256k1_scalar_set_b32(&m, msghash32, NULL);
secp256k1_ecdsa_signature_load(ctx, &r, &s, sig);
return (!secp256k1_scalar_is_high(&s) &&
secp256k1_pubkey_load(ctx, &q, pubkey) &&
secp256k1_ecdsa_sig_verify(&r, &s, &q, &m));
}
static SECP256K1_INLINE void buffer_append(unsigned char *buf, unsigned int *offset, const void *data, unsigned int len) {
memcpy(buf + *offset, data, len);
*offset += len;
}
static int nonce_function_rfc6979(unsigned char *nonce32, const unsigned char *msg32, const unsigned char *key32, const unsigned char *algo16, void *data, unsigned int counter) {
unsigned char keydata[112];
unsigned int offset = 0;
secp256k1_rfc6979_hmac_sha256 rng;
unsigned int i;
secp256k1_scalar msg;
unsigned char msgmod32[32];
secp256k1_scalar_set_b32(&msg, msg32, NULL);
secp256k1_scalar_get_b32(msgmod32, &msg);
/* We feed a byte array to the PRNG as input, consisting of:
* - the private key (32 bytes) and reduced message (32 bytes), see RFC 6979 3.2d.
* - optionally 32 extra bytes of data, see RFC 6979 3.6 Additional Data.
* - optionally 16 extra bytes with the algorithm name.
* Because the arguments have distinct fixed lengths it is not possible for
* different argument mixtures to emulate each other and result in the same
* nonces.
*/
buffer_append(keydata, &offset, key32, 32);
buffer_append(keydata, &offset, msgmod32, 32);
if (data != NULL) {
buffer_append(keydata, &offset, data, 32);
}
if (algo16 != NULL) {
buffer_append(keydata, &offset, algo16, 16);
}
secp256k1_rfc6979_hmac_sha256_initialize(&rng, keydata, offset);
memset(keydata, 0, sizeof(keydata));
for (i = 0; i <= counter; i++) {
secp256k1_rfc6979_hmac_sha256_generate(&rng, nonce32, 32);
}
secp256k1_rfc6979_hmac_sha256_finalize(&rng);
return 1;
}
const secp256k1_nonce_function secp256k1_nonce_function_rfc6979 = nonce_function_rfc6979;
const secp256k1_nonce_function secp256k1_nonce_function_default = nonce_function_rfc6979;
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;
/* 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;
}
/* Fail if the secret key is invalid. */
is_sec_valid = secp256k1_scalar_set_b32_seckey(&sec, seckey);
secp256k1_scalar_cmov(&sec, &secp256k1_scalar_one, !is_sec_valid);
secp256k1_scalar_set_b32(&msg, msg32, NULL);
while (1) {
int is_nonce_valid;
ret = !!noncefp(nonce32, msg32, seckey, NULL, (void*)noncedata, count);
if (!ret) {
break;
}
is_nonce_valid = secp256k1_scalar_set_b32_seckey(&non, nonce32);
/* 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, 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) {
break;
}
}
count++;
}
/* We don't want to declassify is_sec_valid and therefore the range of
* seckey. As a result is_sec_valid is included in ret only after ret was
* used as a branching variable. */
ret &= is_sec_valid;
memset(nonce32, 0, 32);
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);
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 *msghash32, 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(msghash32 != NULL);
ARG_CHECK(signature != NULL);
ARG_CHECK(seckey != NULL);
ret = secp256k1_ecdsa_sign_inner(ctx, &r, &s, NULL, msghash32, seckey, noncefp, noncedata);
secp256k1_ecdsa_signature_save(signature, &r, &s);
return ret;
}
int secp256k1_ec_seckey_verify(const secp256k1_context* ctx, const unsigned char *seckey) {
secp256k1_scalar sec;
int ret;
VERIFY_CHECK(ctx != NULL);
ARG_CHECK(seckey != NULL);
ret = secp256k1_scalar_set_b32_seckey(&sec, seckey);
secp256k1_scalar_clear(&sec);
return ret;
}
static int secp256k1_ec_pubkey_create_helper(const secp256k1_ecmult_gen_context *ecmult_gen_ctx, secp256k1_scalar *seckey_scalar, secp256k1_ge *p, const unsigned char *seckey) {
secp256k1_gej pj;
int ret;
ret = secp256k1_scalar_set_b32_seckey(seckey_scalar, seckey);
secp256k1_scalar_cmov(seckey_scalar, &secp256k1_scalar_one, !ret);
secp256k1_ecmult_gen(ecmult_gen_ctx, &pj, seckey_scalar);
secp256k1_ge_set_gej(p, &pj);
return ret;
}
int secp256k1_ec_pubkey_create(const secp256k1_context* ctx, secp256k1_pubkey *pubkey, const unsigned char *seckey) {
secp256k1_ge p;
secp256k1_scalar seckey_scalar;
int ret = 0;
VERIFY_CHECK(ctx != NULL);
ARG_CHECK(pubkey != NULL);
memset(pubkey, 0, sizeof(*pubkey));
ARG_CHECK(secp256k1_ecmult_gen_context_is_built(&ctx->ecmult_gen_ctx));
ARG_CHECK(seckey != NULL);
ret = secp256k1_ec_pubkey_create_helper(&ctx->ecmult_gen_ctx, &seckey_scalar, &p, seckey);
secp256k1_pubkey_save(pubkey, &p);
secp256k1_memczero(pubkey, sizeof(*pubkey), !ret);
secp256k1_scalar_clear(&seckey_scalar);
return ret;
}
int secp256k1_ec_seckey_negate(const secp256k1_context* ctx, unsigned char *seckey) {
secp256k1_scalar sec;
int ret = 0;
VERIFY_CHECK(ctx != NULL);
ARG_CHECK(seckey != NULL);
ret = secp256k1_scalar_set_b32_seckey(&sec, seckey);
secp256k1_scalar_cmov(&sec, &secp256k1_scalar_zero, !ret);
secp256k1_scalar_negate(&sec, &sec);
secp256k1_scalar_get_b32(seckey, &sec);
secp256k1_scalar_clear(&sec);
return ret;
}
int secp256k1_ec_privkey_negate(const secp256k1_context* ctx, unsigned char *seckey) {
return secp256k1_ec_seckey_negate(ctx, seckey);
}
int secp256k1_ec_pubkey_negate(const secp256k1_context* ctx, secp256k1_pubkey *pubkey) {
int ret = 0;
secp256k1_ge p;
VERIFY_CHECK(ctx != NULL);
ARG_CHECK(pubkey != NULL);
ret = secp256k1_pubkey_load(ctx, &p, pubkey);
memset(pubkey, 0, sizeof(*pubkey));
if (ret) {
secp256k1_ge_neg(&p, &p);
secp256k1_pubkey_save(pubkey, &p);
}
return ret;
}
static int secp256k1_ec_seckey_tweak_add_helper(secp256k1_scalar *sec, const unsigned char *tweak32) {
secp256k1_scalar term;
int overflow = 0;
int ret = 0;
secp256k1_scalar_set_b32(&term, tweak32, &overflow);
ret = (!overflow) & secp256k1_eckey_privkey_tweak_add(sec, &term);
secp256k1_scalar_clear(&term);
return ret;
}
int secp256k1_ec_seckey_tweak_add(const secp256k1_context* ctx, unsigned char *seckey, const unsigned char *tweak32) {
secp256k1_scalar sec;
int ret = 0;
VERIFY_CHECK(ctx != NULL);
ARG_CHECK(seckey != NULL);
ARG_CHECK(tweak32 != NULL);
ret = secp256k1_scalar_set_b32_seckey(&sec, seckey);
ret &= secp256k1_ec_seckey_tweak_add_helper(&sec, tweak32);
secp256k1_scalar_cmov(&sec, &secp256k1_scalar_zero, !ret);
secp256k1_scalar_get_b32(seckey, &sec);
secp256k1_scalar_clear(&sec);
return ret;
}
int secp256k1_ec_privkey_tweak_add(const secp256k1_context* ctx, unsigned char *seckey, const unsigned char *tweak32) {
return secp256k1_ec_seckey_tweak_add(ctx, seckey, tweak32);
}
static int secp256k1_ec_pubkey_tweak_add_helper(secp256k1_ge *p, const unsigned char *tweak32) {
secp256k1_scalar term;
int overflow = 0;
secp256k1_scalar_set_b32(&term, tweak32, &overflow);
return !overflow && secp256k1_eckey_pubkey_tweak_add(p, &term);
}
int secp256k1_ec_pubkey_tweak_add(const secp256k1_context* ctx, secp256k1_pubkey *pubkey, const unsigned char *tweak32) {
secp256k1_ge p;
int ret = 0;
VERIFY_CHECK(ctx != NULL);
ARG_CHECK(pubkey != NULL);
ARG_CHECK(tweak32 != NULL);
ret = secp256k1_pubkey_load(ctx, &p, pubkey);
memset(pubkey, 0, sizeof(*pubkey));
ret = ret && secp256k1_ec_pubkey_tweak_add_helper(&p, tweak32);
if (ret) {
secp256k1_pubkey_save(pubkey, &p);
}
return ret;
}
int secp256k1_ec_seckey_tweak_mul(const secp256k1_context* ctx, unsigned char *seckey, const unsigned char *tweak32) {
secp256k1_scalar factor;
secp256k1_scalar sec;
int ret = 0;
int overflow = 0;
VERIFY_CHECK(ctx != NULL);
ARG_CHECK(seckey != NULL);
ARG_CHECK(tweak32 != NULL);
secp256k1_scalar_set_b32(&factor, tweak32, &overflow);
ret = secp256k1_scalar_set_b32_seckey(&sec, seckey);
ret &= (!overflow) & secp256k1_eckey_privkey_tweak_mul(&sec, &factor);
secp256k1_scalar_cmov(&sec, &secp256k1_scalar_zero, !ret);
secp256k1_scalar_get_b32(seckey, &sec);
secp256k1_scalar_clear(&sec);
secp256k1_scalar_clear(&factor);
return ret;
}
int secp256k1_ec_privkey_tweak_mul(const secp256k1_context* ctx, unsigned char *seckey, const unsigned char *tweak32) {
return secp256k1_ec_seckey_tweak_mul(ctx, seckey, tweak32);
}
int secp256k1_ec_pubkey_tweak_mul(const secp256k1_context* ctx, secp256k1_pubkey *pubkey, const unsigned char *tweak32) {
secp256k1_ge p;
secp256k1_scalar factor;
int ret = 0;
int overflow = 0;
VERIFY_CHECK(ctx != NULL);
ARG_CHECK(pubkey != NULL);
ARG_CHECK(tweak32 != NULL);
secp256k1_scalar_set_b32(&factor, tweak32, &overflow);
ret = !overflow && secp256k1_pubkey_load(ctx, &p, pubkey);
memset(pubkey, 0, sizeof(*pubkey));
if (ret) {
if (secp256k1_eckey_pubkey_tweak_mul(&p, &factor)) {
secp256k1_pubkey_save(pubkey, &p);
} else {
ret = 0;
}
}
return ret;
}
int secp256k1_context_randomize(secp256k1_context* ctx, const unsigned char *seed32) {
VERIFY_CHECK(ctx != NULL);
if (secp256k1_ecmult_gen_context_is_built(&ctx->ecmult_gen_ctx)) {
secp256k1_ecmult_gen_blind(&ctx->ecmult_gen_ctx, seed32);
}
return 1;
}
int secp256k1_ec_pubkey_combine(const secp256k1_context* ctx, secp256k1_pubkey *pubnonce, const secp256k1_pubkey * const *pubnonces, size_t n) {
size_t i;
secp256k1_gej Qj;
secp256k1_ge Q;
VERIFY_CHECK(ctx != NULL);
ARG_CHECK(pubnonce != NULL);
memset(pubnonce, 0, sizeof(*pubnonce));
ARG_CHECK(n >= 1);
ARG_CHECK(pubnonces != NULL);
secp256k1_gej_set_infinity(&Qj);
for (i = 0; i < n; i++) {
ARG_CHECK(pubnonces[i] != NULL);
secp256k1_pubkey_load(ctx, &Q, pubnonces[i]);
secp256k1_gej_add_ge(&Qj, &Qj, &Q);
}
if (secp256k1_gej_is_infinity(&Qj)) {
return 0;
}
secp256k1_ge_set_gej(&Q, &Qj);
secp256k1_pubkey_save(pubnonce, &Q);
return 1;
}
int secp256k1_tagged_sha256(const secp256k1_context* ctx, unsigned char *hash32, const unsigned char *tag, size_t taglen, const unsigned char *msg, size_t msglen) {
secp256k1_sha256 sha;
VERIFY_CHECK(ctx != NULL);
ARG_CHECK(hash32 != NULL);
ARG_CHECK(tag != NULL);
ARG_CHECK(msg != NULL);
secp256k1_sha256_initialize_tagged(&sha, tag, taglen);
secp256k1_sha256_write(&sha, msg, msglen);
secp256k1_sha256_finalize(&sha, hash32);
return 1;
}
#ifdef ENABLE_MODULE_ECDH
# include "modules/ecdh/main_impl.h"
#endif
#ifdef ENABLE_MODULE_RECOVERY
# include "modules/recovery/main_impl.h"
#endif
#ifdef ENABLE_MODULE_EXTRAKEYS
# include "modules/extrakeys/main_impl.h"
#endif
#ifdef ENABLE_MODULE_SCHNORRSIG
# include "modules/schnorrsig/main_impl.h"
#endif
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