svn commit: r483393 - in head/security/openssl111: . files
Cy Schubert
Cy.Schubert at cschubert.com
Mon Oct 29 19:29:06 UTC 2018
In message <201810291807.w9TI7eeg048928 at repo.freebsd.org>, Bernard Spil
writes:
> Author: brnrd
> Date: Mon Oct 29 18:07:39 2018
> New Revision: 483393
> URL: https://svnweb.freebsd.org/changeset/ports/483393
>
> Log:
> security/openssl111: Fix vulnerabilities
>
> MFH: 2018Q4
> Security: 238ae7de-dba2-11e8-b713-b499baebfeaf
>
> Added:
> head/security/openssl111/files/patch-CVE-2018-0734 (contents, props chang
> ed)
> head/security/openssl111/files/patch-CVE-2018-0735 (contents, props chang
> ed)
> Modified:
> head/security/openssl111/Makefile
>
> Modified: head/security/openssl111/Makefile
> =============================================================================
> =
> --- head/security/openssl111/Makefile Mon Oct 29 17:58:14 2018 (r48339
> 2)
> +++ head/security/openssl111/Makefile Mon Oct 29 18:07:39 2018 (r48339
> 3)
> @@ -3,7 +3,7 @@
>
> PORTNAME= openssl
> DISTVERSION= 1.1.1
> -PORTREVISION= 1
> +PORTREVISION= 2
> CATEGORIES= security devel
> MASTER_SITES= https://www.openssl.org/source/ \
> ftp://ftp.cert.dfn.de/pub/tools/net/openssl/source/
>
> Added: head/security/openssl111/files/patch-CVE-2018-0734
> =============================================================================
> =
> --- /dev/null 00:00:00 1970 (empty, because file is newly added)
> +++ head/security/openssl111/files/patch-CVE-2018-0734 Mon Oct 29 18:0
> 7:39 2018 (r483393)
> @@ -0,0 +1,98 @@
> +Timing vulnerability in DSA signature generation (CVE-2018-0734).
> +
> +Avoid a timing attack that leaks information via a side channel that
> +triggers when a BN is resized. Increasing the size of the BNs
> +prior to doing anything with them suppresses the attack.
> +
> +Thanks due to Samuel Weiser for finding and locating this.
> +
> +Reviewed-by: Bernd Edlinger <bernd.edlinger at hotmail.de>
> +(Merged from #7486)
> +
> +(cherry picked from commit a9cfb8c)
> +
> +https://github.com/openssl/openssl/commit/8abfe72e8c1de1b95f50aa0d9134803b4d
> 00070f
> +--- crypto/dsa/dsa_ossl.c.orig 2018-09-11 12:48:21 UTC
> ++++ crypto/dsa/dsa_ossl.c
> +@@ -9,6 +9,7 @@
> +
> + #include <stdio.h>
> + #include "internal/cryptlib.h"
> ++#include "internal/bn_int.h"
> + #include <openssl/bn.h>
> + #include <openssl/sha.h>
> + #include "dsa_locl.h"
> +@@ -178,9 +179,9 @@ static int dsa_sign_setup(DSA *dsa, BN_C
> + {
> + BN_CTX *ctx = NULL;
> + BIGNUM *k, *kinv = NULL, *r = *rp;
> +- BIGNUM *l, *m;
> ++ BIGNUM *l;
> + int ret = 0;
> +- int q_bits;
> ++ int q_bits, q_words;
> +
> + if (!dsa->p || !dsa->q || !dsa->g) {
> + DSAerr(DSA_F_DSA_SIGN_SETUP, DSA_R_MISSING_PARAMETERS);
> +@@ -189,8 +190,7 @@ static int dsa_sign_setup(DSA *dsa, BN_C
> +
> + k = BN_new();
> + l = BN_new();
> +- m = BN_new();
> +- if (k == NULL || l == NULL || m == NULL)
> ++ if (k == NULL || l == NULL)
> + goto err;
> +
> + if (ctx_in == NULL) {
> +@@ -201,9 +201,9 @@ static int dsa_sign_setup(DSA *dsa, BN_C
> +
> + /* Preallocate space */
> + q_bits = BN_num_bits(dsa->q);
> +- if (!BN_set_bit(k, q_bits)
> +- || !BN_set_bit(l, q_bits)
> +- || !BN_set_bit(m, q_bits))
> ++ q_words = bn_get_top(dsa->q);
> ++ if (!bn_wexpand(k, q_words + 2)
> ++ || !bn_wexpand(l, q_words + 2))
> + goto err;
> +
> + /* Get random k */
> +@@ -238,14 +238,17 @@ static int dsa_sign_setup(DSA *dsa, BN_C
> + * small timing information leakage. We then choose the sum that is
> + * one bit longer than the modulus.
> + *
> +- * TODO: revisit the BN_copy aiming for a memory access agnostic
> +- * conditional copy.
> ++ * There are some concerns about the efficacy of doing this. More
> ++ * specificly refer to the discussion starting with:
> ++ * https://github.com/openssl/openssl/pull/7486#discussion_r2283237
> 05
> ++ * The fix is to rework BN so these gymnastics aren't required.
> + */
> + if (!BN_add(l, k, dsa->q)
> +- || !BN_add(m, l, dsa->q)
> +- || !BN_copy(k, BN_num_bits(l) > q_bits ? l : m))
> ++ || !BN_add(k, l, dsa->q))
> + goto err;
> +
> ++ BN_consttime_swap(BN_is_bit_set(l, q_bits), k, l, q_words + 2);
> ++
> + if ((dsa)->meth->bn_mod_exp != NULL) {
> + if (!dsa->meth->bn_mod_exp(dsa, r, dsa->g, k, dsa->p, ctx,
> + dsa->method_mont_p))
> +@@ -258,7 +261,7 @@ static int dsa_sign_setup(DSA *dsa, BN_C
> + if (!BN_mod(r, r, dsa->q, ctx))
> + goto err;
> +
> +- /* Compute part of 's = inv(k) (m + xr) mod q' */
> ++ /* Compute part of 's = inv(k) (m + xr) mod q' */
> + if ((kinv = BN_mod_inverse(NULL, k, dsa->q, ctx)) == NULL)
> + goto err;
> +
> +@@ -273,7 +276,6 @@ static int dsa_sign_setup(DSA *dsa, BN_C
> + BN_CTX_free(ctx);
> + BN_clear_free(k);
> + BN_clear_free(l);
> +- BN_clear_free(m);
> + return ret;
> + }
> +
>
> Added: head/security/openssl111/files/patch-CVE-2018-0735
> =============================================================================
> =
> --- /dev/null 00:00:00 1970 (empty, because file is newly added)
> +++ head/security/openssl111/files/patch-CVE-2018-0735 Mon Oct 29 18:0
> 7:39 2018 (r483393)
> @@ -0,0 +1,33 @@
> +Timing vulnerability in ECDSA signature generation (CVE-2018-0735)
> +
> +Preallocate an extra limb for some of the big numbers to avoid a reallocatio
> n
> +that can potentially provide a side channel.
> +
> +Reviewed-by: Bernd Edlinger <bernd.edlinger at hotmail.de>
> +(Merged from #7486)
> +
> +(cherry picked from commit 99540ec)
> +
> +https://www.openssl.org/news/secadv/20181029.txt
> +--- crypto/ec/ec_mult.c.orig 2018-09-11 12:48:21 UTC
> ++++ crypto/ec/ec_mult.c
> +@@ -206,8 +206,8 @@ int ec_scalar_mul_ladder(const EC_GROUP
> + */
> + cardinality_bits = BN_num_bits(cardinality);
> + group_top = bn_get_top(cardinality);
> +- if ((bn_wexpand(k, group_top + 1) == NULL)
> +- || (bn_wexpand(lambda, group_top + 1) == NULL)) {
> ++ if ((bn_wexpand(k, group_top + 2) == NULL)
> ++ || (bn_wexpand(lambda, group_top + 2) == NULL)) {
> + ECerr(EC_F_EC_SCALAR_MUL_LADDER, ERR_R_BN_LIB);
> + goto err;
> + }
> +@@ -244,7 +244,7 @@ int ec_scalar_mul_ladder(const EC_GROUP
> + * k := scalar + 2*cardinality
> + */
> + kbit = BN_is_bit_set(lambda, cardinality_bits);
> +- BN_consttime_swap(kbit, k, lambda, group_top + 1);
> ++ BN_consttime_swap(kbit, k, lambda, group_top + 2);
> +
> + group_top = bn_get_top(group->field);
> + if ((bn_wexpand(s->X, group_top) == NULL)
>
Is this something we might want to apply to base as well before 12 is
released?
--
Cheers,
Cy Schubert <Cy.Schubert at cschubert.com>
FreeBSD UNIX: <cy at FreeBSD.org> Web: http://www.FreeBSD.org
The need of the many outweighs the greed of the few.
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