Remove the blinding later to avoid leaking information on the length

of kinv.

Pointed out and fix suggested by David Schrammel and Samuel Weiser

ok jsing

1 files changed, 3 insertions, 3 deletions

diff --git a/src/lib/libcrypto/dsa/dsa_ossl.c b/src/lib/libcrypto/dsa/dsa_ossl.c
index fd56e8feee..50a73c0fa9 100644
--- a/src/lib/libcrypto/dsa/dsa_ossl.c
+++ b/src/lib/libcrypto/dsa/dsa_ossl.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: dsa_ossl.c,v 1.40 2018/11/06 07:02:33 tb Exp $ */
+/* $OpenBSD: dsa_ossl.c,v 1.41 2019/06/04 18:10:11 tb Exp $ */
 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
  * All rights reserved.
  *
@@ -165,9 +165,9 @@ dsa_do_sign(const unsigned char *dgst, int dlen, DSA *dsa)
                 goto err;
         if (!BN_mod_add(s, &bxr, &bm, dsa->q, ctx))             /* s = bm + bxr */
                 goto err;
-        if (!BN_mod_mul(s, s, &binv, dsa->q, ctx))              /* s = m + xr */
+        if (!BN_mod_mul(s, s, kinv, dsa->q, ctx))       /* s = b(m + xr)k^-1 */
                 goto err;
-        if (!BN_mod_mul(s, s, kinv, dsa->q, ctx))
+        if (!BN_mod_mul(s, s, &binv, dsa->q, ctx))      /* s = (m + xr)k^-1 */
                 goto err;
 
         /*