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-rw-r--r--src/secp256k1/src/ecmult_gen_impl.h102
1 files changed, 64 insertions, 38 deletions
diff --git a/src/secp256k1/src/ecmult_gen_impl.h b/src/secp256k1/src/ecmult_gen_impl.h
index 4697753ac8..b63c4d8662 100644
--- a/src/secp256k1/src/ecmult_gen_impl.h
+++ b/src/secp256k1/src/ecmult_gen_impl.h
@@ -11,22 +11,26 @@
#include "group.h"
#include "ecmult_gen.h"
#include "hash_impl.h"
-
-static void secp256k1_ecmult_gen_context_init(secp256k1_ecmult_gen_context_t *ctx) {
+#ifdef USE_ECMULT_STATIC_PRECOMPUTATION
+#include "ecmult_static_context.h"
+#endif
+static void secp256k1_ecmult_gen_context_init(secp256k1_ecmult_gen_context *ctx) {
ctx->prec = NULL;
}
-static void secp256k1_ecmult_gen_context_build(secp256k1_ecmult_gen_context_t *ctx) {
- secp256k1_ge_t prec[1024];
- secp256k1_gej_t gj;
- secp256k1_gej_t nums_gej;
+static void secp256k1_ecmult_gen_context_build(secp256k1_ecmult_gen_context *ctx, const secp256k1_callback* cb) {
+#ifndef USE_ECMULT_STATIC_PRECOMPUTATION
+ secp256k1_ge prec[1024];
+ secp256k1_gej gj;
+ secp256k1_gej nums_gej;
int i, j;
+#endif
if (ctx->prec != NULL) {
return;
}
-
- ctx->prec = (secp256k1_ge_storage_t (*)[64][16])checked_malloc(sizeof(*ctx->prec));
+#ifndef USE_ECMULT_STATIC_PRECOMPUTATION
+ ctx->prec = (secp256k1_ge_storage (*)[64][16])checked_malloc(cb, sizeof(*ctx->prec));
/* get the generator */
secp256k1_gej_set_ge(&gj, &secp256k1_ge_const_g);
@@ -34,77 +38,93 @@ static void secp256k1_ecmult_gen_context_build(secp256k1_ecmult_gen_context_t *c
/* Construct a group element with no known corresponding scalar (nothing up my sleeve). */
{
static const unsigned char nums_b32[33] = "The scalar for this x is unknown";
- secp256k1_fe_t nums_x;
- secp256k1_ge_t nums_ge;
- VERIFY_CHECK(secp256k1_fe_set_b32(&nums_x, nums_b32));
- VERIFY_CHECK(secp256k1_ge_set_xo_var(&nums_ge, &nums_x, 0));
+ secp256k1_fe nums_x;
+ secp256k1_ge nums_ge;
+ int r;
+ r = secp256k1_fe_set_b32(&nums_x, nums_b32);
+ (void)r;
+ VERIFY_CHECK(r);
+ r = secp256k1_ge_set_xo_var(&nums_ge, &nums_x, 0);
+ (void)r;
+ VERIFY_CHECK(r);
secp256k1_gej_set_ge(&nums_gej, &nums_ge);
/* Add G to make the bits in x uniformly distributed. */
- secp256k1_gej_add_ge_var(&nums_gej, &nums_gej, &secp256k1_ge_const_g);
+ secp256k1_gej_add_ge_var(&nums_gej, &nums_gej, &secp256k1_ge_const_g, NULL);
}
/* compute prec. */
{
- secp256k1_gej_t precj[1024]; /* Jacobian versions of prec. */
- secp256k1_gej_t gbase;
- secp256k1_gej_t numsbase;
+ secp256k1_gej precj[1024]; /* Jacobian versions of prec. */
+ secp256k1_gej gbase;
+ secp256k1_gej numsbase;
gbase = gj; /* 16^j * G */
numsbase = nums_gej; /* 2^j * nums. */
for (j = 0; j < 64; j++) {
/* Set precj[j*16 .. j*16+15] to (numsbase, numsbase + gbase, ..., numsbase + 15*gbase). */
precj[j*16] = numsbase;
for (i = 1; i < 16; i++) {
- secp256k1_gej_add_var(&precj[j*16 + i], &precj[j*16 + i - 1], &gbase);
+ secp256k1_gej_add_var(&precj[j*16 + i], &precj[j*16 + i - 1], &gbase, NULL);
}
/* Multiply gbase by 16. */
for (i = 0; i < 4; i++) {
- secp256k1_gej_double_var(&gbase, &gbase);
+ secp256k1_gej_double_var(&gbase, &gbase, NULL);
}
/* Multiply numbase by 2. */
- secp256k1_gej_double_var(&numsbase, &numsbase);
+ secp256k1_gej_double_var(&numsbase, &numsbase, NULL);
if (j == 62) {
/* In the last iteration, numsbase is (1 - 2^j) * nums instead. */
secp256k1_gej_neg(&numsbase, &numsbase);
- secp256k1_gej_add_var(&numsbase, &numsbase, &nums_gej);
+ secp256k1_gej_add_var(&numsbase, &numsbase, &nums_gej, NULL);
}
}
- secp256k1_ge_set_all_gej_var(1024, prec, precj);
+ secp256k1_ge_set_all_gej_var(1024, prec, precj, cb);
}
for (j = 0; j < 64; j++) {
for (i = 0; i < 16; i++) {
secp256k1_ge_to_storage(&(*ctx->prec)[j][i], &prec[j*16 + i]);
}
}
+#else
+ (void)cb;
+ ctx->prec = (secp256k1_ge_storage (*)[64][16])secp256k1_ecmult_static_context;
+#endif
secp256k1_ecmult_gen_blind(ctx, NULL);
}
-static int secp256k1_ecmult_gen_context_is_built(const secp256k1_ecmult_gen_context_t* ctx) {
+static int secp256k1_ecmult_gen_context_is_built(const secp256k1_ecmult_gen_context* ctx) {
return ctx->prec != NULL;
}
-static void secp256k1_ecmult_gen_context_clone(secp256k1_ecmult_gen_context_t *dst,
- const secp256k1_ecmult_gen_context_t *src) {
+static void secp256k1_ecmult_gen_context_clone(secp256k1_ecmult_gen_context *dst,
+ const secp256k1_ecmult_gen_context *src, const secp256k1_callback* cb) {
if (src->prec == NULL) {
dst->prec = NULL;
} else {
- dst->prec = (secp256k1_ge_storage_t (*)[64][16])checked_malloc(sizeof(*dst->prec));
+#ifndef USE_ECMULT_STATIC_PRECOMPUTATION
+ dst->prec = (secp256k1_ge_storage (*)[64][16])checked_malloc(cb, sizeof(*dst->prec));
memcpy(dst->prec, src->prec, sizeof(*dst->prec));
+#else
+ (void)cb;
+ dst->prec = src->prec;
+#endif
dst->initial = src->initial;
dst->blind = src->blind;
}
}
-static void secp256k1_ecmult_gen_context_clear(secp256k1_ecmult_gen_context_t *ctx) {
+static void secp256k1_ecmult_gen_context_clear(secp256k1_ecmult_gen_context *ctx) {
+#ifndef USE_ECMULT_STATIC_PRECOMPUTATION
free(ctx->prec);
+#endif
secp256k1_scalar_clear(&ctx->blind);
secp256k1_gej_clear(&ctx->initial);
ctx->prec = NULL;
}
-static void secp256k1_ecmult_gen(const secp256k1_ecmult_gen_context_t *ctx, secp256k1_gej_t *r, const secp256k1_scalar_t *gn) {
- secp256k1_ge_t add;
- secp256k1_ge_storage_t adds;
- secp256k1_scalar_t gnb;
+static void secp256k1_ecmult_gen(const secp256k1_ecmult_gen_context *ctx, secp256k1_gej *r, const secp256k1_scalar *gn) {
+ secp256k1_ge add;
+ secp256k1_ge_storage adds;
+ secp256k1_scalar gnb;
int bits;
int i, j;
memset(&adds, 0, sizeof(adds));
@@ -136,14 +156,15 @@ static void secp256k1_ecmult_gen(const secp256k1_ecmult_gen_context_t *ctx, secp
}
/* Setup blinding values for secp256k1_ecmult_gen. */
-static void secp256k1_ecmult_gen_blind(secp256k1_ecmult_gen_context_t *ctx, const unsigned char *seed32) {
- secp256k1_scalar_t b;
- secp256k1_gej_t gb;
- secp256k1_fe_t s;
+static void secp256k1_ecmult_gen_blind(secp256k1_ecmult_gen_context *ctx, const unsigned char *seed32) {
+ secp256k1_scalar b;
+ secp256k1_gej gb;
+ secp256k1_fe s;
unsigned char nonce32[32];
secp256k1_rfc6979_hmac_sha256_t rng;
int retry;
- if (!seed32) {
+ unsigned char keydata[64] = {0};
+ if (seed32 == NULL) {
/* When seed is NULL, reset the initial point and blinding value. */
secp256k1_gej_set_ge(&ctx->initial, &secp256k1_ge_const_g);
secp256k1_gej_neg(&ctx->initial, &ctx->initial);
@@ -155,13 +176,18 @@ static void secp256k1_ecmult_gen_blind(secp256k1_ecmult_gen_context_t *ctx, cons
* and guards against weak or adversarial seeds. This is a simpler and safer interface than
* asking the caller for blinding values directly and expecting them to retry on failure.
*/
- secp256k1_rfc6979_hmac_sha256_initialize(&rng, seed32 ? seed32 : nonce32, 32, nonce32, 32, NULL, 0);
+ memcpy(keydata, nonce32, 32);
+ if (seed32 != NULL) {
+ memcpy(keydata + 32, seed32, 32);
+ }
+ secp256k1_rfc6979_hmac_sha256_initialize(&rng, keydata, seed32 ? 64 : 32);
+ memset(keydata, 0, sizeof(keydata));
/* Retry for out of range results to achieve uniformity. */
do {
secp256k1_rfc6979_hmac_sha256_generate(&rng, nonce32, 32);
retry = !secp256k1_fe_set_b32(&s, nonce32);
retry |= secp256k1_fe_is_zero(&s);
- } while (retry);
+ } while (retry); /* This branch true is cryptographically unreachable. Requires sha256_hmac output > Fp. */
/* Randomize the projection to defend against multiplier sidechannels. */
secp256k1_gej_rescale(&ctx->initial, &s);
secp256k1_fe_clear(&s);
@@ -170,7 +196,7 @@ static void secp256k1_ecmult_gen_blind(secp256k1_ecmult_gen_context_t *ctx, cons
secp256k1_scalar_set_b32(&b, nonce32, &retry);
/* A blinding value of 0 works, but would undermine the projection hardening. */
retry |= secp256k1_scalar_is_zero(&b);
- } while (retry);
+ } while (retry); /* This branch true is cryptographically unreachable. Requires sha256_hmac output > order. */
secp256k1_rfc6979_hmac_sha256_finalize(&rng);
memset(nonce32, 0, 32);
secp256k1_ecmult_gen(ctx, &gb, &b);
generated by cgit v1.2.3 (git 2.26.2) at 2024-12-03 06:33:47 +0000