From: Dmitry Eremin-Solenikov <dbaryshkov@gmail.com>
Date: Wed, 10 Oct 2018 17:26:25 +0000 (+0200)
Subject: ctr16: fix encryption if src == dst
X-Git-Tag: nettle_3.5rc1~43
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=cd2d1e28184b9924bceda22aab7d09e8034352b3;p=thirdparty%2Fnettle.git

ctr16: fix encryption if src == dst
---

diff --git a/ChangeLog b/ChangeLog
index 16560c14..01515575 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+2018-10-10  Dmitry Eremin-Solenikov  <dbaryshkov@gmail.com>
+
+	* ctr16.c (_ctr_crypt16): Bugfix for the src == dst case, when
+	processing more than on full block of size CTR_BUFFER_LIMIT, src
+	and dst arguments to memxor3 were not properly updated.
+
 2018-10-10  Niels Möller  <nisse@lysator.liu.se>
 
 	* aes-set-encrypt-key.c: Add missing include of stdlib.h.
diff --git a/ctr16.c b/ctr16.c
index 60418e8b..7e1c23d2 100644
--- a/ctr16.c
+++ b/ctr16.c
@@ -91,7 +91,7 @@ _ctr_crypt16(const void *ctx, nettle_cipher_func *f,
 	  f(ctx, CTR_BUFFER_LIMIT, buffer->b, buffer->b);
 	  if (length - i < CTR_BUFFER_LIMIT)
 	    goto done;
-	  memxor3 (dst, src, buffer->b, CTR_BUFFER_LIMIT);
+	  memxor3 (dst + i, src + i, buffer->b, CTR_BUFFER_LIMIT);
 	}
 
       if (blocks > 0)