diff options
author | Samuel Weiser <samuel.weiser@iaik.tugraz.at> | 2017-09-15 22:12:53 +0200 |
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committer | Matt Caswell <matt@openssl.org> | 2017-09-27 10:03:31 +0100 |
commit | 3de81a5912041a70884cf4e52e7213f3b5dfa747 (patch) | |
tree | 5444dc1c4baf00a99eaee7766d9a477c791aca7a /crypto/bn | |
parent | 7966101e20abdcf1da4815dc41e47f52cce02f0f (diff) |
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)
Diffstat (limited to 'crypto/bn')
-rw-r--r-- | crypto/bn/bn_mont.c | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/crypto/bn/bn_mont.c b/crypto/bn/bn_mont.c index 9dad113d02..0985de2d82 100644 --- a/crypto/bn/bn_mont.c +++ b/crypto/bn/bn_mont.c @@ -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) |