X-Git-Url: https://git.cryptolib.org/?a=blobdiff_plain;f=host%2Fgf256mul.c;h=d10b69cab50b173a36c7659bc2976f98bb996cf6;hb=ba3a6079e5184898daed9b3cd67e453a0fc5e637;hp=3da67cb53fc0e6a8087124dce458aa1c702ce723;hpb=b3daeff2bc9d451afc9c311034a122c6495cc1ab;p=avr-crypto-lib.git

diff --git a/host/gf256mul.c b/host/gf256mul.c
index 3da67cb..d10b69c 100644
--- a/host/gf256mul.c
+++ b/host/gf256mul.c
@@ -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;
 }