/* aes_enc.c */
/*
- This file is part of the Crypto-avr-lib/microcrypt-lib.
+ This file is part of the AVR-Crypto-Lib.
Copyright (C) 2008 Daniel Otte (daniel.otte@rub.de)
This program is free software: you can redistribute it and/or modify
#include "aes_enc.h"
#include <avr/pgmspace.h>
-
-void aes_shiftrow(void* data, uint8_t shift){
+void aes_shiftcol(void* data, uint8_t shift){
uint8_t tmp[4];
- tmp[0] = ((uint8_t*)data)[(0+shift)&3];
- tmp[1] = ((uint8_t*)data)[(1+shift)&3];
- tmp[2] = ((uint8_t*)data)[(2+shift)&3];
- tmp[3] = ((uint8_t*)data)[(3+shift)&3];
- memcpy(data, tmp, 4);
+ tmp[0] = ((uint8_t*)data)[ 0];
+ tmp[1] = ((uint8_t*)data)[ 4];
+ tmp[2] = ((uint8_t*)data)[ 8];
+ tmp[3] = ((uint8_t*)data)[12];
+ ((uint8_t*)data)[ 0] = tmp[(shift+0)&3];
+ ((uint8_t*)data)[ 4] = tmp[(shift+1)&3];
+ ((uint8_t*)data)[ 8] = tmp[(shift+2)&3];
+ ((uint8_t*)data)[12] = tmp[(shift+3)&3];
}
#define GF256MUL_1(a) (a)
#define GF256MUL_2(a) (gf256mul(2, (a), 0x1b))
#define GF256MUL_3(a) (gf256mul(3, (a), 0x1b))
-
-
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){
tmp[i] = pgm_read_byte(aes_sbox+state->s[i]);
}
/* shiftRows */
- aes_shiftrow(tmp+4, 1);
- aes_shiftrow(tmp+8, 2);
- aes_shiftrow(tmp+12, 3);
+ aes_shiftcol(tmp+1, 1);
+ aes_shiftcol(tmp+2, 2);
+ aes_shiftcol(tmp+3, 3);
/* mixColums */
for(i=0; i<4; ++i){
- state->s[4*0+i] =
- GF256MUL_2(tmp[4*0+i])
- ^ GF256MUL_3(tmp[4*1+i])
- ^ GF256MUL_1(tmp[4*2+i])
- ^ GF256MUL_1(tmp[4*3+i]);
- state->s[4*1+i] =
- GF256MUL_1(tmp[4*0+i])
- ^ GF256MUL_2(tmp[4*1+i])
- ^ GF256MUL_3(tmp[4*2+i])
- ^ GF256MUL_1(tmp[4*3+i]);
- state->s[4*2+i] =
- GF256MUL_1(tmp[4*0+i])
- ^ GF256MUL_1(tmp[4*1+i])
- ^ GF256MUL_2(tmp[4*2+i])
- ^ GF256MUL_3(tmp[4*3+i]);
- state->s[4*3+i] =
- GF256MUL_3(tmp[4*0+i])
- ^ GF256MUL_1(tmp[4*1+i])
- ^ GF256MUL_1(tmp[4*2+i])
- ^ GF256MUL_2(tmp[4*3+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]^tmp[4*i+1])
+ ^ tmp[4*i+0]
+ ^ t;
+ state->s[4*i+1] =
+ GF256MUL_2(tmp[4*i+1]^tmp[4*i+2])
+ ^ tmp[4*i+1]
+ ^ t;
+ state->s[4*i+2] =
+ GF256MUL_2(tmp[4*i+2]^tmp[4*i+3])
+ ^ tmp[4*i+2]
+ ^ t;
+ state->s[4*i+3] =
+ GF256MUL_2(tmp[4*i+3]^tmp[4*i+0])
+ ^ tmp[4*i+3]
+ ^ t;
}
/* addKey */
state->s[i] = pgm_read_byte(aes_sbox+state->s[i]);
}
/* shiftRows */
- aes_shiftrow(state->s+4, 1);
- aes_shiftrow(state->s+8, 2);
- aes_shiftrow(state->s+12, 3);
+ aes_shiftcol(state->s+1, 1);
+ aes_shiftcol(state->s+2, 2);
+ aes_shiftcol(state->s+3, 3);
/* keyAdd */
for(i=0; i<16; ++i){
state->s[i] ^= k->ks[i];