/* aes_key.c */
/*
 * Copyright (C) 2005
 * Akira Iwata & Masayuki Sato
 * Akira Iwata Laboratory,
 * Nagoya Institute of Technology in Japan.
 *
 * All rights reserved.
 *
 * This software is written by Masayuki Sato.
 * And if you want to contact us, send an email to Kimitake Wakayama
 * (wakayama@elcom.nitech.ac.jp)
 *
 * Redistribution and use in source and binary forms, with or without modification,
 * are permitted provided that the following conditions are met:
 * 
 * 1. Redistributions of source code must retain the above copyright notice,
 *    this list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright notice,
 *    this list of conditions and the following disclaimer in the documentation
 *    and/or other materials provided with the distribution.
 *
 * 3. All advertising materials mentioning features or use of this software must
 *    display the following acknowledgment:
 *    "This product includes software developed by Akira Iwata Laboratory,
 *    Nagoya Institute of Technology in Japan (http://mars.elcom.nitech.ac.jp/)."
 *
 * 4. Redistributions of any form whatsoever must retain the following
 *    acknowledgment:
 *    "This product includes software developed by Akira Iwata Laboratory,
 *     Nagoya Institute of Technology in Japan (http://mars.elcom.nitech.ac.jp/)."
 *
 *   THIS SOFTWARE IS PROVIDED "AS IS" WITHOUT EXPRESS OR IMPLIED WARRANTY.
 *   AKIRA IWATA LABORATORY DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS
 *   SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS,
 *   IN NO EVENT SHALL AKIRA IWATA LABORATORY BE LIABLE FOR ANY SPECIAL,
 *   INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING
 *   FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT,
 *   NEGLIGENCE OR OTHER TORTUOUS ACTION, ARISING OUT OF OR IN CONNECTION
 *   WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 *
 */
#include <stdio.h>
#include <stdlib.h>
#include <time.h>
#include "aes.h"

/* **************key generate & key display *******************/
int MakeKey(void){
       int ret,i;
    int ini[32] = {1,2,5,2,1,4,1,5,2,3,2,3,1,5,2,3,2,4,5,2,
		   1,2,4,5,2,5,3,2,3,4,3,2};
       i=0;
    srand(time(NULL));
    while (i < 32) {
	key[i]=(ret=rand()) % 256;srand(ret << ini[i]);++i;
    }
    return 0;
}



int  Key_out(int key[32],int keytype){
    int i=0;int outp;
    switch (keytype / 1000){
    case 128:
	outp = 4;break;
    case 192:
	outp = 6;break;
    case 256:
	outp = 8;break;
    }
	printf("key generate.Key is\t");
    for (i;i < outp*4;++i){
	if (key[i] < 16) printf("0");
	printf("%x",key[i]);}
    printf("\n");
    return 0;
}



/*  **************** key expand ************************ */
int KeySchedule(int type,int key[32]){
    int nk,nb,round;
    int Rcon0[30] = { 
	0x01,0x02, 0x04, 0x08, 
	0x10, 0x20, 0x40, 0x80, 
	0x1b, 0x36, 0x6c, 0xd8, 
	0xab, 0x4d, 0x9a, 0x2f, 
	0x5e, 0xbc, 0x63, 0xc6, 
	0x97, 0x35, 0x6a, 0xd4, 
	0xb3, 0x7d, 0xfa, 0xef, 
	0xc5, 0x91, };
    int i,j,temp[4];
    switch(type) {
    case 128128:
	nk = 4;nb = 4;round = 10;break;
    case 128192:
	nk = 4;nb = 6;round = 12;break;
    case 128256:
	nk = 4;nb = 8;round = 14;break;
    case 192128:
	nk = 6;nb = 4;round = 12;break;
    case 192192:
	nk = 6;nb = 6;round = 12;break;
    case 192256:
	nk = 6;nb = 8;round = 14;break;
    case 256128:
	nk = 8;nb = 4;round = 14;break;
    case 256192:
	nk = 8;nb = 6;round = 14;break;
    case 256256:
	nk = 8;nb = 8;round = 14;break;
    default:
	return -1;
}
      for (j=0;j < nk;++j)
	for (i=0;i < 4;++i)
	    /* 0 word */
	    word[i][j]= key[i+j*4];
    
    /* expanded key is generated */
    for (j=nk;j < nb*(round+1);++j){

	/* RotByte */
	if ((j % nk) == 0){
       			
      temp[0] = SubByte(word[1][j-1]) ^ Rcon0[(j/nk)-1];
		temp[1] = SubByte(word[2][j-1]);
		temp[2] = SubByte(word[3][j-1]);
		temp[3] = SubByte(word[0][j-1]);
	}	
	   
	if ((j % nk) != 0){
	       temp[0] = word[0][j-1];
	       temp[1] = word[1][j-1];
	       temp[2] = word[2][j-1];
	       temp[3] = word[3][j-1];}


	if (nk > 6 && j % nk == 4)
	    for (i=0;i<4;++i) temp[i]=SubByte(temp[i]);
	for (i=0;i<4;++i)
	    word[i][j] = word[i][j-nk] ^ temp[i];
    }
    return 0;
}