speed up

[avr-crypto-lib.git] / aes_enc.c

diff --git a/aes_enc.c b/aes_enc.c
index 244dcff5e2da381eb1945479af70cd12a1717c9b..a9a2607802351fbc736fbfc9130ac48910988af3 100644 (file)
--- a/aes_enc.c
+++ b/aes_enc.c
@@ -51,7 +51,7 @@ void aes_shiftcol(void* data, uint8_t shift){
 
 static
 void aes_enc_round(aes_cipher_state_t* state, const aes_roundkey_t* k){
-       uint8_t tmp[16];
+       uint8_t tmp[16], t;
        uint8_t i;
        /* subBytes */
        for(i=0; i<16; ++i){
@@ -63,26 +63,23 @@ void aes_enc_round(aes_cipher_state_t* state, const aes_roundkey_t* k){
        aes_shiftcol(tmp+3, 3);
        /* mixColums */
        for(i=0; i<4; ++i){
+               t = tmp[4*i+0] ^ tmp[4*i+1] ^ tmp[4*i+2] ^ tmp[4*i+3];
                state->s[4*i+0] =
-                         GF256MUL_2(tmp[4*i+0])
-                       ^ GF256MUL_3(tmp[4*i+1])
-                       ^ GF256MUL_1(tmp[4*i+2])
-                       ^ GF256MUL_1(tmp[4*i+3]);
+                         GF256MUL_2(tmp[4*i+0]^tmp[4*i+1])
+                       ^ tmp[4*i+0]
+                       ^ t;
                state->s[4*i+1] =
-                         GF256MUL_1(tmp[4*i+0])
-                       ^ GF256MUL_2(tmp[4*i+1])
-                       ^ GF256MUL_3(tmp[4*i+2])
-                       ^ GF256MUL_1(tmp[4*i+3]);
+                         GF256MUL_2(tmp[4*i+1]^tmp[4*i+2])
+                       ^ tmp[4*i+1]
+                       ^ t;
                state->s[4*i+2] =
-                         GF256MUL_1(tmp[4*i+0])
-                       ^ GF256MUL_1(tmp[4*i+1])
-                       ^ GF256MUL_2(tmp[4*i+2])
-                       ^ GF256MUL_3(tmp[4*i+3]);
+                         GF256MUL_2(tmp[4*i+2]^tmp[4*i+3])
+                       ^ tmp[4*i+2]
+                       ^ t;
                state->s[4*i+3] =
-                         GF256MUL_3(tmp[4*i+0])
-                       ^ GF256MUL_1(tmp[4*i+1])
-                       ^ GF256MUL_1(tmp[4*i+2])
-                       ^ GF256MUL_2(tmp[4*i+3]);               
+                         GF256MUL_2(tmp[4*i+3]^tmp[4*i+0])
+                       ^ tmp[4*i+3]
+                       ^ t;
        }
 
        /* addKey */