X-Git-Url: https://git.cryptolib.org/?p=avr-crypto-lib.git;a=blobdiff_plain;f=host%2Fgf256mul.c;h=fe6548652483220d4b63d9e9ef6385911a0f758e;hp=3da67cb53fc0e6a8087124dce458aa1c702ce723;hb=4b5da1dc27a791b5c448274a3db09cd035b33493;hpb=b3daeff2bc9d451afc9c311034a122c6495cc1ab

diff --git a/host/gf256mul.c b/host/gf256mul.c
index 3da67cb..fe65486 100644
--- a/host/gf256mul.c
+++ b/host/gf256mul.c
@@ -1,7 +1,7 @@
 /* gf256mul.c */
 /*
-    This file is part of the Crypto-avr-lib/microcrypt-lib.
-    Copyright (C) 2008  Daniel Otte (daniel.otte@rub.de)
+    This file is part of the AVR-Crypto-Lib.
+    Copyright (C) 2006-2015 Daniel Otte (bg@nerilex.org)
 
     This program is free software: you can redistribute it and/or modify
     it under the terms of the GNU General Public License as published by
@@ -18,7 +18,7 @@
 */
 /**
  * \file     gf256mul.c
- * \email    daniel.otte@rub.de
+ * \email    bg@nerilex.org
  * \author   Daniel Otte 
  * \date     2009-01-13
  * \license  GPLv3 or later
@@ -28,15 +28,16 @@
 #include "gf256mul.h"
 
 uint8_t gf256mul(uint8_t a, uint8_t b, uint8_t reducer){
-	uint8_t t,ret=0;
-	while(a){
-		if(a&1)
-			ret ^= b;
+	uint8_t i;
+	uint8_t p=0,t;
+	for(i=0; i<8; ++i){
+		if(b&1)
+			p ^= a;
 		t=a&0x80;
-		b<<=1;
+		a<<=1;
 		if(t)
-			b^=reducer;
-		a>>=1;
+			a ^= reducer;
+		b>>=1;
 	}
-	return ret;
+	return p;
 }