9c4a8514d6
* gnu/packages/patches/openssl-CVE-2016-2177.patch, gnu/packages/patches/openssl-CVE-2016-2178.patch: New files. * gnu/local.mk (dist_patch_DATA): Add them. * gnu/packages/tls.scm (openssl/fixed): Use them.
113 lines
3.6 KiB
Diff
113 lines
3.6 KiB
Diff
Fix CVE-2016-2178.
|
|
|
|
<https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2016-2178>
|
|
|
|
Source:
|
|
<https://git.openssl.org/?p=openssl.git;a=commit;h=621eaf49a289bfac26d4cbcdb7396e796784c534>
|
|
<https://git.openssl.org/?p=openssl.git;a=commit;h=b7d0f2834e139a20560d64c73e2565e93715ce2b>
|
|
|
|
From 621eaf49a289bfac26d4cbcdb7396e796784c534 Mon Sep 17 00:00:00 2001
|
|
From: Cesar Pereida <cesar.pereida@aalto.fi>
|
|
Date: Mon, 23 May 2016 12:45:25 +0300
|
|
Subject: [PATCH 1/2] Fix DSA, preserve BN_FLG_CONSTTIME
|
|
|
|
Operations in the DSA signing algorithm should run in constant time in
|
|
order to avoid side channel attacks. A flaw in the OpenSSL DSA
|
|
implementation means that a non-constant time codepath is followed for
|
|
certain operations. This has been demonstrated through a cache-timing
|
|
attack to be sufficient for an attacker to recover the private DSA key.
|
|
|
|
CVE-2016-2178
|
|
|
|
Reviewed-by: Richard Levitte <levitte@openssl.org>
|
|
Reviewed-by: Matt Caswell <matt@openssl.org>
|
|
---
|
|
crypto/dsa/dsa_ossl.c | 6 +++---
|
|
1 file changed, 3 insertions(+), 3 deletions(-)
|
|
|
|
diff --git a/crypto/dsa/dsa_ossl.c b/crypto/dsa/dsa_ossl.c
|
|
index efc4f1b..b29eb4b 100644
|
|
--- a/crypto/dsa/dsa_ossl.c
|
|
+++ b/crypto/dsa/dsa_ossl.c
|
|
@@ -248,9 +248,6 @@ static int dsa_sign_setup(DSA *dsa, BN_CTX *ctx_in, BIGNUM **kinvp,
|
|
if (!BN_rand_range(&k, dsa->q))
|
|
goto err;
|
|
while (BN_is_zero(&k)) ;
|
|
- if ((dsa->flags & DSA_FLAG_NO_EXP_CONSTTIME) == 0) {
|
|
- BN_set_flags(&k, BN_FLG_CONSTTIME);
|
|
- }
|
|
|
|
if (dsa->flags & DSA_FLAG_CACHE_MONT_P) {
|
|
if (!BN_MONT_CTX_set_locked(&dsa->method_mont_p,
|
|
@@ -279,9 +276,12 @@ static int dsa_sign_setup(DSA *dsa, BN_CTX *ctx_in, BIGNUM **kinvp,
|
|
}
|
|
|
|
K = &kq;
|
|
+
|
|
+ BN_set_flags(K, BN_FLG_CONSTTIME);
|
|
} else {
|
|
K = &k;
|
|
}
|
|
+
|
|
DSA_BN_MOD_EXP(goto err, dsa, r, dsa->g, K, dsa->p, ctx,
|
|
dsa->method_mont_p);
|
|
if (!BN_mod(r, r, dsa->q, ctx))
|
|
--
|
|
2.8.4
|
|
|
|
From b7d0f2834e139a20560d64c73e2565e93715ce2b Mon Sep 17 00:00:00 2001
|
|
From: Matt Caswell <matt@openssl.org>
|
|
Date: Tue, 7 Jun 2016 09:12:51 +0100
|
|
Subject: [PATCH 2/2] More fix DSA, preserve BN_FLG_CONSTTIME
|
|
|
|
The previous "fix" still left "k" exposed to constant time problems in
|
|
the later BN_mod_inverse() call. Ensure both k and kq have the
|
|
BN_FLG_CONSTTIME flag set at the earliest opportunity after creation.
|
|
|
|
CVE-2016-2178
|
|
|
|
Reviewed-by: Rich Salz <rsalz@openssl.org>
|
|
---
|
|
crypto/dsa/dsa_ossl.c | 11 ++++++++---
|
|
1 file changed, 8 insertions(+), 3 deletions(-)
|
|
|
|
diff --git a/crypto/dsa/dsa_ossl.c b/crypto/dsa/dsa_ossl.c
|
|
index b29eb4b..58013a4 100644
|
|
--- a/crypto/dsa/dsa_ossl.c
|
|
+++ b/crypto/dsa/dsa_ossl.c
|
|
@@ -247,7 +247,12 @@ static int dsa_sign_setup(DSA *dsa, BN_CTX *ctx_in, BIGNUM **kinvp,
|
|
do
|
|
if (!BN_rand_range(&k, dsa->q))
|
|
goto err;
|
|
- while (BN_is_zero(&k)) ;
|
|
+ while (BN_is_zero(&k));
|
|
+
|
|
+ if ((dsa->flags & DSA_FLAG_NO_EXP_CONSTTIME) == 0) {
|
|
+ BN_set_flags(&k, BN_FLG_CONSTTIME);
|
|
+ }
|
|
+
|
|
|
|
if (dsa->flags & DSA_FLAG_CACHE_MONT_P) {
|
|
if (!BN_MONT_CTX_set_locked(&dsa->method_mont_p,
|
|
@@ -261,6 +266,8 @@ static int dsa_sign_setup(DSA *dsa, BN_CTX *ctx_in, BIGNUM **kinvp,
|
|
if (!BN_copy(&kq, &k))
|
|
goto err;
|
|
|
|
+ BN_set_flags(&kq, BN_FLG_CONSTTIME);
|
|
+
|
|
/*
|
|
* We do not want timing information to leak the length of k, so we
|
|
* compute g^k using an equivalent exponent of fixed length. (This
|
|
@@ -276,8 +283,6 @@ static int dsa_sign_setup(DSA *dsa, BN_CTX *ctx_in, BIGNUM **kinvp,
|
|
}
|
|
|
|
K = &kq;
|
|
-
|
|
- BN_set_flags(K, BN_FLG_CONSTTIME);
|
|
} else {
|
|
K = &k;
|
|
}
|
|
--
|
|
2.8.4
|
|
|