	/* aes_enc.c */
	/*
	    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
	    it under the terms of the GNU General Public License as published by
	    the Free Software Foundation, either version 3 of the License, or
	    (at your option) any later version.
	
	    This program is distributed in the hope that it will be useful,
	    but WITHOUT ANY WARRANTY; without even the implied warranty of
	    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
	    GNU General Public License for more details.
	
	    You should have received a copy of the GNU General Public License
	    along with this program.  If not, see <http://www.gnu.org/licenses/>.
	*/
	/**
	 * \file     aes_enc.c
	 * \email    daniel.otte@rub.de
	 * \author   Daniel Otte
	 * \date     2008-12-30
	 * \license  GPLv3 or later
	 *
	 */
	
	#include <stdint.h>
	#include <string.h>
	#include "aes.h"
	#include "gf256mul.h"
	#include "aes_sbox.h"
	#include "aes_enc.h"
	#include <avr/pgmspace.h>
	
	#include <avr/io.h>
	
	void aes_shiftcol(void* data, uint8_t shift){
	        uint8_t 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], t;
	        uint8_t i;
	        /* subBytes */
	        for(i=0; i<16; ++i){
	                tmp[i] = pgm_read_byte(aes_sbox+state->s[i]);
        }    
	        /* shiftRows */
	        aes_shiftcol(tmp+1, 1);
					
			/* Vypne LED0 a LED1 pri sifrovani prvni rundy sifry AES. */
			PORTB = ~0b00000000;
					
	        aes_shiftcol(tmp+2, 2);
	        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]^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 */
	        for(i=0; i<16; ++i){
	                state->s[i] ^= k->ks[i];
	        }
	}
	
	
	static
	void aes_enc_lastround(aes_cipher_state_t* state,const aes_roundkey_t* k){
	        uint8_t i;
	        /* subBytes */
	        for(i=0; i<16; ++i){
	                state->s[i] = pgm_read_byte(aes_sbox+state->s[i]);
	        }
	        /* shiftRows */
	        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];
	        }
	}
	
	void aes_encrypt_core(aes_cipher_state_t* state, const aes_genctx_t* ks, uint8_t rounds){
	        uint8_t i;
			
			/* Zapne LED0 a LED1 pri zacatku operace AddRoundKey. */
			PORTB = ~0b00000011;
			
	        for(i=0; i<16; ++i){
	                state->s[i] ^= ks->key[0].ks[i];
	        }
	        i=1;
			for(; rounds>1; --rounds){
				aes_enc_round(state, &(ks->key[i]));
				++i;	               
	        }
	        aes_enc_lastround(state, &(ks->key[i]));
	}
	
	/*
	void aes_encrypt_core(aes_cipher_state_t* state, const aes_genctx_t* ks, uint8_t rounds){
			uint8_t i;
			for(i=0; i<16; ++i){
				state->s[i] ^= ks->key[0].ks[i];
			}
			i=1;
			for(;rounds>1;--rounds){
				aes_enc_round(state, &(ks->key[i]));
				++i;
			}
			aes_enc_lastround(state, &(ks->key[i]));
	}
	*/