diff options
Diffstat (limited to 'src/secp256k1/src/ecmult_gen_impl.h')
-rw-r--r-- | src/secp256k1/src/ecmult_gen_impl.h | 25 |
1 files changed, 14 insertions, 11 deletions
diff --git a/src/secp256k1/src/ecmult_gen_impl.h b/src/secp256k1/src/ecmult_gen_impl.h index 07859ab04b..5a5b16ce14 100644 --- a/src/secp256k1/src/ecmult_gen_impl.h +++ b/src/secp256k1/src/ecmult_gen_impl.h @@ -23,8 +23,8 @@ typedef struct { * precomputed (call it prec(i, n_i)). The formula now becomes sum(prec(i, n_i), i=0..63). * None of the resulting prec group elements have a known scalar, and neither do any of * the intermediate sums while computing a*G. - * To make memory access uniform, the bytes of prec(i, n_i) are sliced per value of n_i. */ - unsigned char prec[64][sizeof(secp256k1_ge_t)][16]; /* prec[j][k][i] = k'th byte of (16^j * i * G + U_i) */ + */ + secp256k1_fe_t prec[64][16][2]; /* prec[j][i] = (16^j * i * G + U_i).{x,y} */ } secp256k1_ecmult_gen_consts_t; static const secp256k1_ecmult_gen_consts_t *secp256k1_ecmult_gen_consts = NULL; @@ -34,7 +34,7 @@ static void secp256k1_ecmult_gen_start(void) { return; /* Allocate the precomputation table. */ - secp256k1_ecmult_gen_consts_t *ret = (secp256k1_ecmult_gen_consts_t*)malloc(sizeof(secp256k1_ecmult_gen_consts_t)); + secp256k1_ecmult_gen_consts_t *ret = (secp256k1_ecmult_gen_consts_t*)checked_malloc(sizeof(secp256k1_ecmult_gen_consts_t)); /* get the generator */ const secp256k1_ge_t *g = &secp256k1_ge_consts->g; @@ -45,9 +45,9 @@ static void secp256k1_ecmult_gen_start(void) { { static const unsigned char nums_b32[32] = "The scalar for this x is unknown"; secp256k1_fe_t nums_x; - secp256k1_fe_set_b32(&nums_x, nums_b32); + VERIFY_CHECK(secp256k1_fe_set_b32(&nums_x, nums_b32)); secp256k1_ge_t nums_ge; - VERIFY_CHECK(secp256k1_ge_set_xo(&nums_ge, &nums_x, 0)); + VERIFY_CHECK(secp256k1_ge_set_xo_var(&nums_ge, &nums_x, 0)); 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, g); @@ -73,7 +73,7 @@ static void secp256k1_ecmult_gen_start(void) { secp256k1_gej_double_var(&numsbase, &numsbase); if (j == 62) { /* In the last iteration, numsbase is (1 - 2^j) * nums instead. */ - secp256k1_gej_neg(&numsbase, &numsbase); + secp256k1_gej_neg_var(&numsbase, &numsbase); secp256k1_gej_add_var(&numsbase, &numsbase, &nums_gej); } } @@ -81,9 +81,9 @@ static void secp256k1_ecmult_gen_start(void) { } for (int j=0; j<64; j++) { for (int i=0; i<16; i++) { - const unsigned char* raw = (const unsigned char*)(&prec[j*16 + i]); - for (size_t k=0; k<sizeof(secp256k1_ge_t); k++) - ret->prec[j][k][i] = raw[k]; + VERIFY_CHECK(!secp256k1_ge_is_infinity(&prec[j*16 + i])); + ret->prec[j][i][0] = prec[j*16 + i].x; + ret->prec[j][i][1] = prec[j*16 + i].y; } } @@ -104,11 +104,14 @@ static void secp256k1_ecmult_gen(secp256k1_gej_t *r, const secp256k1_scalar_t *g const secp256k1_ecmult_gen_consts_t *c = secp256k1_ecmult_gen_consts; secp256k1_gej_set_infinity(r); secp256k1_ge_t add; + add.infinity = 0; int bits; for (int j=0; j<64; j++) { bits = secp256k1_scalar_get_bits(gn, j * 4, 4); - for (size_t k=0; k<sizeof(secp256k1_ge_t); k++) - ((unsigned char*)(&add))[k] = c->prec[j][k][bits]; + for (int i=0; i<16; i++) { + secp256k1_fe_cmov(&add.x, &c->prec[j][i][0], i == bits); + secp256k1_fe_cmov(&add.y, &c->prec[j][i][1], i == bits); + } secp256k1_gej_add_ge(r, r, &add); } bits = 0; |