diff options
| author | Andrew Golovashevich <tankist.scratch.p@gmail.com> | 2024-05-05 14:27:26 +0300 |
|---|---|---|
| committer | Tomas Mraz <tomas@openssl.org> | 2024-05-15 13:37:48 +0200 |
| commit | aaa1bda7187c8d920cf9e426c2cf8ec7c1c65576 (patch) | |
| tree | 5951432ff285f06fa34a518a4fc3fd230a6fd2a7 /include | |
| parent | 5a0c92cf093b4f0aa65f4fdbff88d7bdc83491f3 (diff) | |
Optimizated calculation of shared power of 2 in bn_gcd
Reviewed-by: Paul Dale <ppzgs1@gmail.com>
Reviewed-by: Bernd Edlinger <bernd.edlinger@hotmail.de>
Reviewed-by: Tomas Mraz <tomas@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/24332)
Diffstat (limited to 'include')
| -rw-r--r-- | include/internal/constant_time.h | 18 |
1 files changed, 18 insertions, 0 deletions
diff --git a/include/internal/constant_time.h b/include/internal/constant_time.h index f2572ded51..9ffa4399a3 100644 --- a/include/internal/constant_time.h +++ b/include/internal/constant_time.h @@ -141,6 +141,17 @@ static ossl_inline uint64_t constant_time_lt_64(uint64_t a, uint64_t b) } #ifdef BN_ULONG +static ossl_inline BN_ULONG value_barrier_bn(BN_ULONG a) +{ +#if !defined(OPENSSL_NO_ASM) && defined(__GNUC__) + BN_ULONG r; + __asm__("" : "=r"(r) : "0"(a)); +#else + volatile BN_ULONG r = a; +#endif + return r; +} + static ossl_inline BN_ULONG constant_time_msb_bn(BN_ULONG a) { return 0 - (a >> (sizeof(a) * 8 - 1)); @@ -161,6 +172,13 @@ static ossl_inline BN_ULONG constant_time_eq_bn(BN_ULONG a, { return constant_time_is_zero_bn(a ^ b); } + +static ossl_inline BN_ULONG constant_time_select_bn(BN_ULONG mask, + BN_ULONG a, + BN_ULONG b) +{ + return (value_barrier_bn(mask) & a) | (value_barrier_bn(~mask) & b); +} #endif static ossl_inline unsigned int constant_time_ge(unsigned int a, |