diff options
Diffstat (limited to 'src/secp256k1/src/num_gmp_impl.h')
-rw-r--r-- | src/secp256k1/src/num_gmp_impl.h | 184 |
1 files changed, 20 insertions, 164 deletions
diff --git a/src/secp256k1/src/num_gmp_impl.h b/src/secp256k1/src/num_gmp_impl.h index e45a59e0cd..19d474e59f 100644 --- a/src/secp256k1/src/num_gmp_impl.h +++ b/src/secp256k1/src/num_gmp_impl.h @@ -22,35 +22,10 @@ static void secp256k1_num_sanity(const secp256k1_num_t *a) { #define secp256k1_num_sanity(a) do { } while(0) #endif -static void secp256k1_num_init(secp256k1_num_t *r) { - r->neg = 0; - r->limbs = 1; - r->data[0] = 0; -} - -static void secp256k1_num_clear(secp256k1_num_t *r) { - memset(r, 0, sizeof(*r)); -} - -static void secp256k1_num_free(secp256k1_num_t *r) { - (void)r; -} - static void secp256k1_num_copy(secp256k1_num_t *r, const secp256k1_num_t *a) { *r = *a; } -static int secp256k1_num_bits(const secp256k1_num_t *a) { - int ret=(a->limbs-1)*GMP_NUMB_BITS; - mp_limb_t x=a->data[a->limbs-1]; - while (x) { - x >>= 1; - ret++; - } - return ret; -} - - static void secp256k1_num_get_bin(unsigned char *r, unsigned int rlen, const secp256k1_num_t *a) { unsigned char tmp[65]; int len = 0; @@ -71,18 +46,16 @@ static void secp256k1_num_set_bin(secp256k1_num_t *r, const unsigned char *a, un VERIFY_CHECK(alen > 0); VERIFY_CHECK(alen <= 64); int len = mpn_set_str(r->data, a, alen, 256); + if (len == 0) { + r->data[0] = 0; + len = 1; + } VERIFY_CHECK(len <= NUM_LIMBS*2); r->limbs = len; r->neg = 0; while (r->limbs > 1 && r->data[r->limbs-1]==0) r->limbs--; } -static void secp256k1_num_set_int(secp256k1_num_t *r, int a) { - r->limbs = 1; - r->neg = (a < 0); - r->data[0] = (a < 0) ? -a : a; -} - static void secp256k1_num_add_abs(secp256k1_num_t *r, const secp256k1_num_t *a, const secp256k1_num_t *b) { mp_limb_t c = mpn_add(r->data, a->data, a->limbs, b->data, b->limbs); r->limbs = a->limbs; @@ -161,10 +134,6 @@ static int secp256k1_num_is_zero(const secp256k1_num_t *a) { return (a->limbs == 1 && a->data[0] == 0); } -static int secp256k1_num_is_odd(const secp256k1_num_t *a) { - return a->data[0] & 1; -} - static int secp256k1_num_is_neg(const secp256k1_num_t *a) { return (a->limbs > 1 || a->data[0] != 0) && a->neg; } @@ -237,140 +206,27 @@ static void secp256k1_num_mul(secp256k1_num_t *r, const secp256k1_num_t *a, cons memset(tmp, 0, sizeof(tmp)); } -static void secp256k1_num_div(secp256k1_num_t *r, const secp256k1_num_t *a, const secp256k1_num_t *b) { - secp256k1_num_sanity(a); - secp256k1_num_sanity(b); - if (b->limbs > a->limbs) { - r->limbs = 1; - r->data[0] = 0; - r->neg = 0; - return; - } - - mp_limb_t quo[2*NUM_LIMBS+1]; - mp_limb_t rem[2*NUM_LIMBS+1]; - mpn_tdiv_qr(quo, rem, 0, a->data, a->limbs, b->data, b->limbs); - mpn_copyi(r->data, quo, a->limbs - b->limbs + 1); - r->limbs = a->limbs - b->limbs + 1; - while (r->limbs > 1 && r->data[r->limbs - 1]==0) r->limbs--; - r->neg = a->neg ^ b->neg; -} - -static void secp256k1_num_mod_mul(secp256k1_num_t *r, const secp256k1_num_t *a, const secp256k1_num_t *b, const secp256k1_num_t *m) { - secp256k1_num_mul(r, a, b); - secp256k1_num_mod(r, m); -} - - -static int secp256k1_num_shift(secp256k1_num_t *r, int bits) { - VERIFY_CHECK(bits <= GMP_NUMB_BITS); - mp_limb_t ret = mpn_rshift(r->data, r->data, r->limbs, bits); - if (r->limbs>1 && r->data[r->limbs-1]==0) r->limbs--; - ret >>= (GMP_NUMB_BITS - bits); - return ret; -} - -static int secp256k1_num_get_bit(const secp256k1_num_t *a, int pos) { - return (a->limbs*GMP_NUMB_BITS > pos) && ((a->data[pos/GMP_NUMB_BITS] >> (pos % GMP_NUMB_BITS)) & 1); -} - -static void secp256k1_num_inc(secp256k1_num_t *r) { - mp_limb_t ret = mpn_add_1(r->data, r->data, r->limbs, (mp_limb_t)1); - if (ret) { - VERIFY_CHECK(r->limbs < 2*NUM_LIMBS); - r->data[r->limbs++] = ret; - } -} - -static void secp256k1_num_set_hex(secp256k1_num_t *r, const char *a, int alen) { - static const unsigned char cvt[256] = { - 0, 0, 0, 0, 0, 0, 0,0,0,0,0,0,0,0,0,0, - 0, 0, 0, 0, 0, 0, 0,0,0,0,0,0,0,0,0,0, - 0, 0, 0, 0, 0, 0, 0,0,0,0,0,0,0,0,0,0, - 0, 1, 2, 3, 4, 5, 6,7,8,9,0,0,0,0,0,0, - 0,10,11,12,13,14,15,0,0,0,0,0,0,0,0,0, - 0, 0, 0, 0, 0, 0, 0,0,0,0,0,0,0,0,0,0, - 0,10,11,12,13,14,15,0,0,0,0,0,0,0,0,0, - 0, 0, 0, 0, 0, 0, 0,0,0,0,0,0,0,0,0,0, - 0, 0, 0, 0, 0, 0, 0,0,0,0,0,0,0,0,0,0, - 0, 0, 0, 0, 0, 0, 0,0,0,0,0,0,0,0,0,0, - 0, 0, 0, 0, 0, 0, 0,0,0,0,0,0,0,0,0,0, - 0, 0, 0, 0, 0, 0, 0,0,0,0,0,0,0,0,0,0, - 0, 0, 0, 0, 0, 0, 0,0,0,0,0,0,0,0,0,0, - 0, 0, 0, 0, 0, 0, 0,0,0,0,0,0,0,0,0,0, - 0, 0, 0, 0, 0, 0, 0,0,0,0,0,0,0,0,0,0, - 0, 0, 0, 0, 0, 0, 0,0,0,0,0,0,0,0,0,0 - }; - unsigned char num[257] = {}; - for (int i=0; i<alen; i++) { - num[i] = cvt[(unsigned char)a[i]]; - } - r->limbs = mpn_set_str(r->data, num, alen, 16); - r->neg = 0; - while (r->limbs > 1 && r->data[r->limbs-1] == 0) r->limbs--; -} - -static void secp256k1_num_get_hex(char *r, int rlen, const secp256k1_num_t *a) { - static const unsigned char cvt[16] = {'0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'A', 'B', 'C', 'D', 'E', 'F'}; - unsigned char *tmp = malloc(257); - mp_size_t len = mpn_get_str(tmp, 16, (mp_limb_t*)a->data, a->limbs); - VERIFY_CHECK(len <= rlen); - for (int i=0; i<len; i++) { - VERIFY_CHECK(rlen-len+i >= 0); - VERIFY_CHECK(rlen-len+i < rlen); - VERIFY_CHECK(tmp[i] < 16); - r[rlen-len+i] = cvt[tmp[i]]; - } - for (int i=0; i<rlen-len; i++) { - VERIFY_CHECK(i >= 0); - VERIFY_CHECK(i < rlen); - r[i] = cvt[0]; - } - free(tmp); -} - -static void secp256k1_num_split(secp256k1_num_t *rl, secp256k1_num_t *rh, const secp256k1_num_t *a, int bits) { - VERIFY_CHECK(bits > 0); - rh->neg = a->neg; - if (bits >= a->limbs * GMP_NUMB_BITS) { - *rl = *a; - rh->limbs = 1; - rh->data[0] = 0; - return; - } - rl->limbs = 0; - rl->neg = a->neg; - int left = bits; - while (left >= GMP_NUMB_BITS) { - rl->data[rl->limbs] = a->data[rl->limbs]; - rl->limbs++; - left -= GMP_NUMB_BITS; - } - if (left == 0) { - mpn_copyi(rh->data, a->data + rl->limbs, a->limbs - rl->limbs); - rh->limbs = a->limbs - rl->limbs; - } else { - mpn_rshift(rh->data, a->data + rl->limbs, a->limbs - rl->limbs, left); - rh->limbs = a->limbs - rl->limbs; - while (rh->limbs>1 && rh->data[rh->limbs-1]==0) rh->limbs--; - } - if (left > 0) { - rl->data[rl->limbs] = a->data[rl->limbs] & ((((mp_limb_t)1) << left) - 1); - rl->limbs++; +static void secp256k1_num_shift(secp256k1_num_t *r, int bits) { + if (bits % GMP_NUMB_BITS) { + // Shift within limbs. + mpn_rshift(r->data, r->data, r->limbs, bits % GMP_NUMB_BITS); + } + if (bits >= GMP_NUMB_BITS) { + // Shift full limbs. + for (int i = 0; i < r->limbs; i++) { + int index = i + (bits / GMP_NUMB_BITS); + if (index < r->limbs && index < 2*NUM_LIMBS) { + r->data[i] = r->data[index]; + } else { + r->data[i] = 0; + } + } } - while (rl->limbs>1 && rl->data[rl->limbs-1]==0) rl->limbs--; + while (r->limbs>1 && r->data[r->limbs-1]==0) r->limbs--; } static void secp256k1_num_negate(secp256k1_num_t *r) { r->neg ^= 1; } -static int secp256k1_num_get_bits(const secp256k1_num_t *a, int offset, int count) { - int ret = 0; - for (int i = 0; i < count; i++) { - ret |= ((a->data[(offset + i) / GMP_NUMB_BITS] >> ((offset + i) % GMP_NUMB_BITS)) & 1) << i; - } - return ret; -} - #endif |