lilliput-ae-reference-implementation

commit ae461f64bd249f959411b8b7cf56e549bb2ecb5c
parent efc65320b38cb51b2786c8f08df1a37de75e97a2
Author: Kévin Le Gouguec <kevin.legouguec@gmail.com>
Date:   Fri,  1 Feb 2019 14:00:05 +0100

Implémentation de M₁

Diffstat:
M
src/add_developedtweakey/tweakey.c
 | 
16
+++++++++++++---

1 file changed, 13 insertions(+), 3 deletions(-)
diff --git a/src/add_developedtweakey/tweakey.c b/src/add_developedtweakey/tweakey.c
@@ -43,6 +43,11 @@ void tweakey_state_extract(
 }
 
 
+static uint8_t _M1(uint8_t x)
+{
+    return x<<3 ^ x>>3;
+}
+
 static void _multiply_M(const uint8_t X[LANE_BYTES], uint8_t Y[LANE_BYTES])
 {
     Y[7] = X[6];
@@ -57,9 +62,14 @@ static void _multiply_M(const uint8_t X[LANE_BYTES], uint8_t Y[LANE_BYTES])
 
 static void _multiply_M2(const uint8_t X[LANE_BYTES], uint8_t Y[LANE_BYTES])
 {
-    uint8_t M_X[LANE_BYTES];
-    _multiply_M(X, M_X);
-    _multiply_M(M_X, Y);
+    Y[7] = X[5];
+    Y[6] = X[5]<<3 ^ X[4];
+    Y[5] = X[5]<<6 ^ _M1(X[4]) ^ X[3];
+    Y[4] = X[4]>>6 ^ X[3]>>3   ^ X[2];
+    Y[3] = X[6]<<2 ^ X[1];
+    Y[2] = X[5]<<2 ^ X[0];
+    Y[1] = X[7];
+    Y[0] = X[6];
 }
 
 static void _multiply_M3(const uint8_t X[LANE_BYTES], uint8_t Y[LANE_BYTES])