diff options
Diffstat (limited to 'crypto/bn/bn_lib.c')
| -rw-r--r-- | crypto/bn/bn_lib.c | 13 |
1 files changed, 13 insertions, 0 deletions
diff --git a/crypto/bn/bn_lib.c b/crypto/bn/bn_lib.c index 57fe45288b..a446880ec7 100644 --- a/crypto/bn/bn_lib.c +++ b/crypto/bn/bn_lib.c @@ -739,6 +739,19 @@ void BN_consttime_swap(BN_ULONG condition, BIGNUM *a, BIGNUM *b, int nwords) a->top ^= t; b->top ^= t; + t = (a->neg ^ b->neg) & condition; + a->neg ^= t; + b->neg ^= t; + + /* + * cannot just arbitrarily swap flags. + * The way a->d is allocated etc. + * BN_FLG_MALLOCED, BN_FLG_STATIC_DATA, ... + */ + t = (a->flags ^ b->flags) & condition & BN_FLG_CONSTTIME; + a->flags ^= t; + b->flags ^= t; + #define BN_CONSTTIME_SWAP(ind) \ do { \ t = (a->d[ind] ^ b->d[ind]) & condition; \ |