diff --git a/crypto/bn/bn_exp.c b/crypto/bn/bn_exp.c index cfbaf2b66f..6e3a7264d5 100644 --- a/crypto/bn/bn_exp.c +++ b/crypto/bn/bn_exp.c @@ -691,7 +691,8 @@ int BN_mod_exp_mont_consttime(BIGNUM *rr, const BIGNUM *a, const BIGNUM *p, * RSAZ exponentiation. For further information see * crypto/bn/rsaz_exp.c and accompanying assembly modules. */ - if ((16 == a->top) && (16 == p->top) && (BN_num_bits(m) == 1024) + if (((OPENSSL_ia32cap_P[2]&0x80100) != 0x80100) /* check for MULX/AD*X */ + && (16 == a->top) && (16 == p->top) && (BN_num_bits(m) == 1024) && rsaz_avx2_eligible()) { if (NULL == bn_wexpand(rr, 16)) goto err;