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authorSamuel Weiser <samuel.weiser@iaik.tugraz.at>2017-09-15 22:12:53 +0200
committerMatt Caswell <matt@openssl.org>2017-09-27 10:03:31 +0100
commit3de81a5912041a70884cf4e52e7213f3b5dfa747 (patch)
tree5444dc1c4baf00a99eaee7766d9a477c791aca7a /crypto/bn/bn_mont.c
parent7966101e20abdcf1da4815dc41e47f52cce02f0f (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/bn_mont.c')
-rw-r--r--crypto/bn/bn_mont.c5
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)