From: Samuel Weiser <samuel.weiser@iaik.tugraz.at>
Date: Fri, 29 Sep 2017 11:29:25 +0000 (+0200)
Subject: Added const-time flag to DSA key decoding to avoid potential leak of privkey
X-Git-Tag: OpenSSL_1_1_0g~58
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=15ab3217799db508dec4c78cbfd185129f8fdfec;p=openssl

Added const-time flag to DSA key decoding to avoid potential leak of privkey

Reviewed-by: Richard Levitte <levitte@openssl.org>
Reviewed-by: Rich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/4440)

(cherry picked from commit 6364475a990449ef33fc270ac00472f7210220f2)
---

diff --git a/crypto/dsa/dsa_ameth.c b/crypto/dsa/dsa_ameth.c
index 7c0428d3f6..fbb9121469 100644
--- a/crypto/dsa/dsa_ameth.c
+++ b/crypto/dsa/dsa_ameth.c
@@ -175,6 +175,7 @@ static int dsa_priv_decode(EVP_PKEY *pkey, const PKCS8_PRIV_KEY_INFO *p8)
         goto dsaerr;
     }
 
+    BN_set_flags(dsa->priv_key, BN_FLG_CONSTTIME);
     if (!BN_mod_exp(dsa->pub_key, dsa->g, dsa->priv_key, dsa->p, ctx)) {
         DSAerr(DSA_F_DSA_PRIV_DECODE, DSA_R_BN_ERROR);
         goto dsaerr;