diff options
Diffstat (limited to 'nss/lib/freebl/ecl/uint128.c')
| -rw-r--r-- | nss/lib/freebl/ecl/uint128.c | 5 |
1 files changed, 4 insertions, 1 deletions
diff --git a/nss/lib/freebl/ecl/uint128.c b/nss/lib/freebl/ecl/uint128.c index 22cbd02..5465875 100644 --- a/nss/lib/freebl/ecl/uint128.c +++ b/nss/lib/freebl/ecl/uint128.c @@ -31,6 +31,9 @@ init128x(uint64_t x) return ret; } +#define CONSTANT_TIME_CARRY(a, b) \ + ((a ^ ((a ^ b) | ((a - b) ^ b))) >> (sizeof(a) * 8 - 1)) + /* arithmetic */ uint128_t @@ -38,7 +41,7 @@ add128(uint128_t a, uint128_t b) { uint128_t ret; ret.lo = a.lo + b.lo; - ret.hi = a.hi + b.hi + (ret.lo < b.lo); + ret.hi = a.hi + b.hi + CONSTANT_TIME_CARRY(ret.lo, b.lo); return ret; } |