Adaptation du code de α₃

1 files changed, 10 insertions, 10 deletions

diff --git a/src/add_tweakeyunrolled/tweakey.c b/src/add_tweakeyunrolled/tweakey.c
index a5b88a8..7f80a2a 100644
--- a/src/add_tweakeyunrolled/tweakey.c
+++ b/src/add_tweakeyunrolled/tweakey.c
@@ -67,11 +67,6 @@ static uint8_t _M1(uint8_t x)
     return x<<3 ^ x>>3;
 }
 
-static uint8_t _M2(uint8_t x)
-{
-    return x<<6 ^ (x>>3)<<3 ^ x>>6;
-}
-
 static uint8_t _M3(uint8_t x)
 {
     return (uint8_t)(x<<3) >> 3;
@@ -111,12 +106,17 @@ static void _multiply_M2(const uint8_t x[LANE_BYTES], uint8_t y[LANE_BYTES])
 
 static void _multiply_M3(const uint8_t x[LANE_BYTES], uint8_t y[LANE_BYTES])
 {
-    y[7] = x[5]<<3   ^ x[4];
-    y[6] = x[5]<<6   ^ _M1(x[4]) ^ x[3];
-    y[5] = _M2(x[4]) ^ _M1(x[3]) ^ x[2];
-    y[4] = x[6]<<2   ^ x[3]>>6   ^ x[2]>>3 ^ x[1];
+    uint8_t x_M_5  = x[5]<<3  ^ x[4];
+    uint8_t x_M_4  = x[4]>>3  ^ x[3];
+    uint8_t x_M2_5 = x_M_5<<3 ^ x_M_4;
+    uint8_t x_M2_4 = x_M_4>>3 ^ x[2];
+
+    y[7] = x_M_5;
+    y[6] = x_M2_5;
+    y[5] = x_M2_5<<3 ^ x_M2_4;
+    y[4] = x_M2_4>>3 ^ x[6]<<2 ^ x[1];
     y[3] = x[5]<<2   ^ x[0];
-    y[2] = x[7]      ^ x[5]<<5   ^ x[4]<<2;
+    y[2] = x_M_5<<2  ^ x[7];
     y[1] = x[6];
     y[0] = x[5];
 }