From: Bodo Möller <bodo@openssl.org>
Date: Tue, 27 Aug 2002 13:32:35 +0000 (+0000)
Subject: don't write beyond buffer
X-Git-Tag: OpenSSL_0_9_7-beta4~168^2~16
X-Git-Url: https://git.librecmc.org/?a=commitdiff_plain;h=c237de058f91072b5d54ad9c570049c14df6957e;p=oweals%2Fopenssl.git

don't write beyond buffer

Submitted by: Nils Larsch
---

diff --git a/crypto/bn/bn_gf2m.c b/crypto/bn/bn_gf2m.c
index 8bd17e0e7c..dea1fd3b87 100644
--- a/crypto/bn/bn_gf2m.c
+++ b/crypto/bn/bn_gf2m.c
@@ -370,12 +370,16 @@ int BN_GF2m_mod_arr(BIGNUM *r, const BIGNUM *a, const unsigned int p[])
 
 		for (k = 1; p[k] > 0; k++)
 			{
+			BN_ULONG tmp_ulong;
+
 			/* reducing component t^p[k]*/
 			n = p[k] / BN_BITS2;   
 			d0 = p[k] % BN_BITS2;
 			d1 = BN_BITS2 - d0;
 			z[n] ^= (zz << d0);
-			if (d0) z[n+1] ^= (zz >> d1);
+			tmp_ulong = zz >> d1;
+                        if (d0 && tmp_ulong)
+                                z[n+1] ^= tmp_ulong;
 			}