diff options
Diffstat (limited to 'crypto/bn/bn_lib.c')
| -rw-r--r-- | crypto/bn/bn_lib.c | 108 |
1 files changed, 39 insertions, 69 deletions
diff --git a/crypto/bn/bn_lib.c b/crypto/bn/bn_lib.c index f9c65f9f948a9..27b9bdbc3c287 100644 --- a/crypto/bn/bn_lib.c +++ b/crypto/bn/bn_lib.c @@ -144,74 +144,47 @@ const BIGNUM *BN_value_one(void) int BN_num_bits_word(BN_ULONG l) { - static const unsigned char bits[256] = { - 0, 1, 2, 2, 3, 3, 3, 3, 4, 4, 4, 4, 4, 4, 4, 4, - 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, - 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, - 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, - 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, - 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, - 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, - 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, - 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, - 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, - 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, - 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, - 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, - 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, - 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, - 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, - }; + BN_ULONG x, mask; + int bits = (l != 0); -#if defined(SIXTY_FOUR_BIT_LONG) - if (l & 0xffffffff00000000L) { - if (l & 0xffff000000000000L) { - if (l & 0xff00000000000000L) { - return (bits[(int)(l >> 56)] + 56); - } else - return (bits[(int)(l >> 48)] + 48); - } else { - if (l & 0x0000ff0000000000L) { - return (bits[(int)(l >> 40)] + 40); - } else - return (bits[(int)(l >> 32)] + 32); - } - } else -#else -# ifdef SIXTY_FOUR_BIT - if (l & 0xffffffff00000000LL) { - if (l & 0xffff000000000000LL) { - if (l & 0xff00000000000000LL) { - return (bits[(int)(l >> 56)] + 56); - } else - return (bits[(int)(l >> 48)] + 48); - } else { - if (l & 0x0000ff0000000000LL) { - return (bits[(int)(l >> 40)] + 40); - } else - return (bits[(int)(l >> 32)] + 32); - } - } else -# endif -#endif - { -#if defined(THIRTY_TWO_BIT) || defined(SIXTY_FOUR_BIT) || defined(SIXTY_FOUR_BIT_LONG) - if (l & 0xffff0000L) { - if (l & 0xff000000L) - return (bits[(int)(l >> 24L)] + 24); - else - return (bits[(int)(l >> 16L)] + 16); - } else +#if BN_BITS2 > 32 + x = l >> 32; + mask = (0 - x) & BN_MASK2; + mask = (0 - (mask >> (BN_BITS2 - 1))); + bits += 32 & mask; + l ^= (x ^ l) & mask; #endif - { -#if defined(THIRTY_TWO_BIT) || defined(SIXTY_FOUR_BIT) || defined(SIXTY_FOUR_BIT_LONG) - if (l & 0xff00L) - return (bits[(int)(l >> 8)] + 8); - else -#endif - return (bits[(int)(l)]); - } - } + + x = l >> 16; + mask = (0 - x) & BN_MASK2; + mask = (0 - (mask >> (BN_BITS2 - 1))); + bits += 16 & mask; + l ^= (x ^ l) & mask; + + x = l >> 8; + mask = (0 - x) & BN_MASK2; + mask = (0 - (mask >> (BN_BITS2 - 1))); + bits += 8 & mask; + l ^= (x ^ l) & mask; + + x = l >> 4; + mask = (0 - x) & BN_MASK2; + mask = (0 - (mask >> (BN_BITS2 - 1))); + bits += 4 & mask; + l ^= (x ^ l) & mask; + + x = l >> 2; + mask = (0 - x) & BN_MASK2; + mask = (0 - (mask >> (BN_BITS2 - 1))); + bits += 2 & mask; + l ^= (x ^ l) & mask; + + x = l >> 1; + mask = (0 - x) & BN_MASK2; + mask = (0 - (mask >> (BN_BITS2 - 1))); + bits += 1 & mask; + + return bits; } int BN_num_bits(const BIGNUM *a) @@ -524,9 +497,6 @@ BIGNUM *BN_copy(BIGNUM *a, const BIGNUM *b) memcpy(a->d, b->d, sizeof(b->d[0]) * b->top); #endif - if (BN_get_flags(b, BN_FLG_CONSTTIME) != 0) - BN_set_flags(a, BN_FLG_CONSTTIME); - a->top = b->top; a->neg = b->neg; bn_check_top(a); |