[patch] random-drbg-dont-memset-zero.patch

0001-random-random-drbg.c-Don-t-memset-if-length-is-zero.patch (text/plain), 1.41 KB, created by Kristian Fiskerstrand (RETIRED) on 2017-01-25 17:02:05 UTC

From 1e9313920e1fa8a8f82b0ecaa43e84a1669b0081 Mon Sep 17 00:00:00 2001
From: Kristian Fiskerstrand <[e-mail]>
Date: Wed, 25 Jan 2017 17:55:47 +0100
Subject: [PATCH] (random/random-drbg.c) Don't memset if length is zero

A zero length memset triggers __warn_memset_zero_len() in glibc, so
only invoking memset if non-zero value

--
A user reported an issue in
https://bugs.gentoo.org/show_bug.cgi?id=606740

/usr/include/bits/string3.h:86:7: warning: call to
'__warn_memset_zero_len' declared with attribute warning: memset used
with constant zero length parameter; this could be due to transposed
parameters
       __warn_memset_zero_len ();

which subsequently resulted in linking error for
./.libs/libgcrypt.so: undefined reference to `__warn_memset_zero_len'
---
 random/random-drbg.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/random/random-drbg.c b/random/random-drbg.c
index e2fe861..33ae645 100644
--- a/random/random-drbg.c
+++ b/random/random-drbg.c
@@ -1021,7 +1021,8 @@ drbg_hmac_update (drbg_state_t drbg, drbg_string_t *seed, int reseed)
     {
       /* 10.1.2.3 step 2 already implicitly covered with
        * the initial memset(0) of drbg->C */
-      memset (drbg->V, 1, drbg_statelen (drbg));
+      if(drbg_statelen (drbg))
+        memset (drbg->V, 1, drbg_statelen (drbg));
       ret = drbg_hmac_setkey (drbg, drbg->C);
       if (ret)
 	return ret;
-- 
2.10.2