From: leslie <unknown>
Date: Thu, 3 Jan 2008 16:08:06 +0000 (+0100)
Subject: made RotateBytes robust against bad input
X-Git-Tag: 0.8.7~20
X-Git-Url: http://www.vanbest.org/gitweb/?a=commitdiff_plain;h=33f046204c27b23f17d33487b35709c6a04f67a4;p=sasc-ng.git

made RotateBytes robust against bad input
---

diff --git a/crypto.c b/crypto.c
index c1e64cc..a6c5bb4 100644
--- a/crypto.c
+++ b/crypto.c
@@ -29,22 +29,22 @@
 
 void RotateBytes(unsigned char *out, const unsigned char *in, int n)
 {
-  // loop is executed atleast once, so it's not a good idea to
-  // call with n=0 !!
-  out+=n;
-  do { *(--out)=*(in++); } while(--n);
+  if(n>0) {
+    out+=n;
+    do { *(--out)=*(in++); } while(--n);
+    }
 }
 
 void RotateBytes(unsigned char *in, int n)
 {
-  // loop is executed atleast once, so it's not a good idea to
-  // call with n=0 !!
-  unsigned char *e=in+n-1;
-  do {
-    unsigned char temp=*in;
-    *in++=*e;
-    *e-- =temp;
-    } while(in<e);
+  if(n>1) {
+    unsigned char *e=in+n-1;
+    do {
+      unsigned char temp=*in;
+      *in++=*e;
+      *e-- =temp;
+      } while(in<e);
+    }
 }
 
 // -- cBN ----------------------------------------------------------------------