diff options
Diffstat (limited to 'gnu/packages/patches/openssl-CVE-2016-2178.patch')
| -rw-r--r-- | gnu/packages/patches/openssl-CVE-2016-2178.patch | 112 |
1 files changed, 112 insertions, 0 deletions
diff --git a/gnu/packages/patches/openssl-CVE-2016-2178.patch b/gnu/packages/patches/openssl-CVE-2016-2178.patch new file mode 100644 index 0000000000..37cf2763af --- /dev/null +++ b/gnu/packages/patches/openssl-CVE-2016-2178.patch @@ -0,0 +1,112 @@ +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 + |