mirror of
https://github.com/openwrt/openwrt.git
synced 2024-12-23 07:22:33 +00:00
b463a13881
This fixes the following security problems: * CVE-2019-9494: cache attack against SAE * CVE-2019-9495: cache attack against EAP-pwd * CVE-2019-9496: SAE confirm missing state validation in hostapd/AP * CVE-2019-9497: EAP-pwd server not checking for reflection attack) * CVE-2019-9498: EAP-pwd server missing commit validation for scalar/element * CVE-2019-9499: EAP-pwd peer missing commit validation for scalar/element * CVE-2019-11555: EAP-pwd message reassembly issue with unexpected fragment Most of these problems are not relevant for normal users, SAE is only used in ieee80211s mesh mode and EAP-pwd is normally not activated. Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>
89 lines
3.3 KiB
Diff
89 lines
3.3 KiB
Diff
From d42c477cc794163a3757956bbffca5cea000923c Mon Sep 17 00:00:00 2001
|
|
From: Jouni Malinen <jouni@codeaurora.org>
|
|
Date: Tue, 26 Feb 2019 11:43:03 +0200
|
|
Subject: [PATCH 01/14] OpenSSL: Use constant time operations for private
|
|
bignums
|
|
|
|
This helps in reducing measurable timing differences in operations
|
|
involving private information. BoringSSL has removed BN_FLG_CONSTTIME
|
|
and expects specific constant time functions to be called instead, so a
|
|
bit different approach is needed depending on which library is used.
|
|
|
|
The main operation that needs protection against side channel attacks is
|
|
BN_mod_exp() that depends on private keys (the public key validation
|
|
step in crypto_dh_derive_secret() is an exception that can use the
|
|
faster version since it does not depend on private keys).
|
|
|
|
crypto_bignum_div() is currently used only in SAE FFC case with not
|
|
safe-prime groups and only with values that do not depend on private
|
|
keys, so it is not critical to protect it.
|
|
|
|
crypto_bignum_inverse() is currently used only in SAE FFC PWE
|
|
derivation. The additional protection here is targeting only OpenSSL.
|
|
BoringSSL may need conversion to using BN_mod_inverse_blinded().
|
|
|
|
This is related to CVE-2019-9494 and CVE-2019-9495.
|
|
|
|
Signed-off-by: Jouni Malinen <jouni@codeaurora.org>
|
|
---
|
|
src/crypto/crypto_openssl.c | 20 +++++++++++++++-----
|
|
1 file changed, 15 insertions(+), 5 deletions(-)
|
|
|
|
--- a/src/crypto/crypto_openssl.c
|
|
+++ b/src/crypto/crypto_openssl.c
|
|
@@ -548,7 +548,8 @@ int crypto_mod_exp(const u8 *base, size_
|
|
bn_result == NULL)
|
|
goto error;
|
|
|
|
- if (BN_mod_exp(bn_result, bn_base, bn_exp, bn_modulus, ctx) != 1)
|
|
+ if (BN_mod_exp_mont_consttime(bn_result, bn_base, bn_exp, bn_modulus,
|
|
+ ctx, NULL) != 1)
|
|
goto error;
|
|
|
|
*result_len = BN_bn2bin(bn_result, result);
|
|
@@ -1294,8 +1295,9 @@ int crypto_bignum_exptmod(const struct c
|
|
bnctx = BN_CTX_new();
|
|
if (bnctx == NULL)
|
|
return -1;
|
|
- res = BN_mod_exp((BIGNUM *) d, (const BIGNUM *) a, (const BIGNUM *) b,
|
|
- (const BIGNUM *) c, bnctx);
|
|
+ res = BN_mod_exp_mont_consttime((BIGNUM *) d, (const BIGNUM *) a,
|
|
+ (const BIGNUM *) b, (const BIGNUM *) c,
|
|
+ bnctx, NULL);
|
|
BN_CTX_free(bnctx);
|
|
|
|
return res ? 0 : -1;
|
|
@@ -1314,6 +1316,11 @@ int crypto_bignum_inverse(const struct c
|
|
bnctx = BN_CTX_new();
|
|
if (bnctx == NULL)
|
|
return -1;
|
|
+#ifdef OPENSSL_IS_BORINGSSL
|
|
+ /* TODO: use BN_mod_inverse_blinded() ? */
|
|
+#else /* OPENSSL_IS_BORINGSSL */
|
|
+ BN_set_flags((BIGNUM *) a, BN_FLG_CONSTTIME);
|
|
+#endif /* OPENSSL_IS_BORINGSSL */
|
|
res = BN_mod_inverse((BIGNUM *) c, (const BIGNUM *) a,
|
|
(const BIGNUM *) b, bnctx);
|
|
BN_CTX_free(bnctx);
|
|
@@ -1347,6 +1354,9 @@ int crypto_bignum_div(const struct crypt
|
|
bnctx = BN_CTX_new();
|
|
if (bnctx == NULL)
|
|
return -1;
|
|
+#ifndef OPENSSL_IS_BORINGSSL
|
|
+ BN_set_flags((BIGNUM *) a, BN_FLG_CONSTTIME);
|
|
+#endif /* OPENSSL_IS_BORINGSSL */
|
|
res = BN_div((BIGNUM *) c, NULL, (const BIGNUM *) a,
|
|
(const BIGNUM *) b, bnctx);
|
|
BN_CTX_free(bnctx);
|
|
@@ -1438,8 +1448,8 @@ int crypto_bignum_legendre(const struct
|
|
/* exp = (p-1) / 2 */
|
|
!BN_sub(exp, (const BIGNUM *) p, BN_value_one()) ||
|
|
!BN_rshift1(exp, exp) ||
|
|
- !BN_mod_exp(tmp, (const BIGNUM *) a, exp, (const BIGNUM *) p,
|
|
- bnctx))
|
|
+ !BN_mod_exp_mont_consttime(tmp, (const BIGNUM *) a, exp,
|
|
+ (const BIGNUM *) p, bnctx, NULL))
|
|
goto fail;
|
|
|
|
if (BN_is_word(tmp, 1))
|