Fixed error in propagating BN_FLG_CONSTTIME flag through BN_MONT_CTX_set, which could lead to information disclosure on RSA primes p and q.

Reviewed-by: Paul Dale <paul.dale@oracle.com>
Reviewed-by: Matt Caswell <matt@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/4377)
This commit is contained in:
Samuel Weiser 2017-09-15 22:12:53 +02:00 committed by Matt Caswell
parent 7966101e20
commit 3de81a5912

View File

@ -258,6 +258,8 @@ int BN_MONT_CTX_set(BN_MONT_CTX *mont, const BIGNUM *mod, BN_CTX *ctx)
R = &(mont->RR); /* grab RR as a temp */
if (!BN_copy(&(mont->N), mod))
goto err; /* Set N */
if (BN_get_flags(mod, BN_FLG_CONSTTIME) != 0)
BN_set_flags(&(mont->N), BN_FLG_CONSTTIME);
mont->N.neg = 0;
#ifdef MONT_WORD
@ -270,6 +272,9 @@ int BN_MONT_CTX_set(BN_MONT_CTX *mont, const BIGNUM *mod, BN_CTX *ctx)
tmod.dmax = 2;
tmod.neg = 0;
if (BN_get_flags(mod, BN_FLG_CONSTTIME) != 0)
BN_set_flags(&tmod, BN_FLG_CONSTTIME);
mont->ri = (BN_num_bits(mod) + (BN_BITS2 - 1)) / BN_BITS2 * BN_BITS2;
# if defined(OPENSSL_BN_ASM_MONT) && (BN_BITS2<=32)