MySensors/drivers/AES/AES.cpp

#include "AES.h"

/*
 ---------------------------------------------------------------------------
 Copyright (c) 1998-2008, Brian Gladman, Worcester, UK. All rights reserved.

 LICENSE TERMS

 The redistribution and use of this software (with or without changes)
 is allowed without the payment of fees or royalties provided that:

  1. source code distributions include the above copyright notice, this
     list of conditions and the following disclaimer;

  2. binary distributions include the above copyright notice, this list
     of conditions and the following disclaimer in their documentation;

  3. the name of the copyright holder is not used to endorse products
     built using this software without specific written permission.

 DISCLAIMER

 This software is provided 'as is' with no explicit or implied warranties
 in respect of its properties, including, but not limited to, correctness
 and/or fitness for purpose.
 ---------------------------------------------------------------------------
 Issue 09/09/2006

 This is an AES implementation that uses only 8-bit byte operations on the
 cipher state (there are options to use 32-bit types if available).

 The combination of mix columns and byte substitution used here is based on
 that developed by Karl Malbrain. His contribution is acknowledged.
 */

/* This version derived by Mark Tillotson 2012-01-23, tidied up, slimmed down
   and tailored to 8-bit microcontroller abilities and Arduino datatypes.

   The s-box and inverse s-box were retained as tables (0.5kB PROGMEM) but all
   the other transformations are coded to save table space.  Many efficiency
   improvments to the routines mix_sub_columns() and inv_mix_sub_columns()
   (mainly common sub-expression elimination).

   Only the routines with precalculated subkey schedule are retained (together
   with set_key() - this does however mean each AES object takes 240 bytes of
   RAM, alas)

   The CBC routines side-effect the iv argument (so that successive calls work
   together correctly).

   All the encryption and decryption routines work with plain == cipher for
   in-place encryption, note.

*/


/* functions for finite field multiplication in the AES Galois field    */

/* code was modified by george spanos <spaniakos@gmail.com>
 * 16/12/14
 */

// GF(2^8) stuff

#define WPOLY   0x011B
#define DPOLY   0x008D

const static byte s_fwd [0x100] PROGMEM = {
	0x63, 0x7c, 0x77, 0x7b, 0xf2, 0x6b, 0x6f, 0xc5, 0x30, 0x01, 0x67, 0x2b, 0xfe, 0xd7, 0xab, 0x76,
	0xca, 0x82, 0xc9, 0x7d, 0xfa, 0x59, 0x47, 0xf0, 0xad, 0xd4, 0xa2, 0xaf, 0x9c, 0xa4, 0x72, 0xc0,
	0xb7, 0xfd, 0x93, 0x26, 0x36, 0x3f, 0xf7, 0xcc, 0x34, 0xa5, 0xe5, 0xf1, 0x71, 0xd8, 0x31, 0x15,
	0x04, 0xc7, 0x23, 0xc3, 0x18, 0x96, 0x05, 0x9a, 0x07, 0x12, 0x80, 0xe2, 0xeb, 0x27, 0xb2, 0x75,
	0x09, 0x83, 0x2c, 0x1a, 0x1b, 0x6e, 0x5a, 0xa0, 0x52, 0x3b, 0xd6, 0xb3, 0x29, 0xe3, 0x2f, 0x84,
	0x53, 0xd1, 0x00, 0xed, 0x20, 0xfc, 0xb1, 0x5b, 0x6a, 0xcb, 0xbe, 0x39, 0x4a, 0x4c, 0x58, 0xcf,
	0xd0, 0xef, 0xaa, 0xfb, 0x43, 0x4d, 0x33, 0x85, 0x45, 0xf9, 0x02, 0x7f, 0x50, 0x3c, 0x9f, 0xa8,
	0x51, 0xa3, 0x40, 0x8f, 0x92, 0x9d, 0x38, 0xf5, 0xbc, 0xb6, 0xda, 0x21, 0x10, 0xff, 0xf3, 0xd2,
	0xcd, 0x0c, 0x13, 0xec, 0x5f, 0x97, 0x44, 0x17, 0xc4, 0xa7, 0x7e, 0x3d, 0x64, 0x5d, 0x19, 0x73,
	0x60, 0x81, 0x4f, 0xdc, 0x22, 0x2a, 0x90, 0x88, 0x46, 0xee, 0xb8, 0x14, 0xde, 0x5e, 0x0b, 0xdb,
	0xe0, 0x32, 0x3a, 0x0a, 0x49, 0x06, 0x24, 0x5c, 0xc2, 0xd3, 0xac, 0x62, 0x91, 0x95, 0xe4, 0x79,
	0xe7, 0xc8, 0x37, 0x6d, 0x8d, 0xd5, 0x4e, 0xa9, 0x6c, 0x56, 0xf4, 0xea, 0x65, 0x7a, 0xae, 0x08,
	0xba, 0x78, 0x25, 0x2e, 0x1c, 0xa6, 0xb4, 0xc6, 0xe8, 0xdd, 0x74, 0x1f, 0x4b, 0xbd, 0x8b, 0x8a,
	0x70, 0x3e, 0xb5, 0x66, 0x48, 0x03, 0xf6, 0x0e, 0x61, 0x35, 0x57, 0xb9, 0x86, 0xc1, 0x1d, 0x9e,
	0xe1, 0xf8, 0x98, 0x11, 0x69, 0xd9, 0x8e, 0x94, 0x9b, 0x1e, 0x87, 0xe9, 0xce, 0x55, 0x28, 0xdf,
	0x8c, 0xa1, 0x89, 0x0d, 0xbf, 0xe6, 0x42, 0x68, 0x41, 0x99, 0x2d, 0x0f, 0xb0, 0x54, 0xbb, 0x16,
} ;

const static byte s_inv [0x100] PROGMEM = {
	0x52, 0x09, 0x6a, 0xd5, 0x30, 0x36, 0xa5, 0x38, 0xbf, 0x40, 0xa3, 0x9e, 0x81, 0xf3, 0xd7, 0xfb,
	0x7c, 0xe3, 0x39, 0x82, 0x9b, 0x2f, 0xff, 0x87, 0x34, 0x8e, 0x43, 0x44, 0xc4, 0xde, 0xe9, 0xcb,
	0x54, 0x7b, 0x94, 0x32, 0xa6, 0xc2, 0x23, 0x3d, 0xee, 0x4c, 0x95, 0x0b, 0x42, 0xfa, 0xc3, 0x4e,
	0x08, 0x2e, 0xa1, 0x66, 0x28, 0xd9, 0x24, 0xb2, 0x76, 0x5b, 0xa2, 0x49, 0x6d, 0x8b, 0xd1, 0x25,
	0x72, 0xf8, 0xf6, 0x64, 0x86, 0x68, 0x98, 0x16, 0xd4, 0xa4, 0x5c, 0xcc, 0x5d, 0x65, 0xb6, 0x92,
	0x6c, 0x70, 0x48, 0x50, 0xfd, 0xed, 0xb9, 0xda, 0x5e, 0x15, 0x46, 0x57, 0xa7, 0x8d, 0x9d, 0x84,
	0x90, 0xd8, 0xab, 0x00, 0x8c, 0xbc, 0xd3, 0x0a, 0xf7, 0xe4, 0x58, 0x05, 0xb8, 0xb3, 0x45, 0x06,
	0xd0, 0x2c, 0x1e, 0x8f, 0xca, 0x3f, 0x0f, 0x02, 0xc1, 0xaf, 0xbd, 0x03, 0x01, 0x13, 0x8a, 0x6b,
	0x3a, 0x91, 0x11, 0x41, 0x4f, 0x67, 0xdc, 0xea, 0x97, 0xf2, 0xcf, 0xce, 0xf0, 0xb4, 0xe6, 0x73,
	0x96, 0xac, 0x74, 0x22, 0xe7, 0xad, 0x35, 0x85, 0xe2, 0xf9, 0x37, 0xe8, 0x1c, 0x75, 0xdf, 0x6e,
	0x47, 0xf1, 0x1a, 0x71, 0x1d, 0x29, 0xc5, 0x89, 0x6f, 0xb7, 0x62, 0x0e, 0xaa, 0x18, 0xbe, 0x1b,
	0xfc, 0x56, 0x3e, 0x4b, 0xc6, 0xd2, 0x79, 0x20, 0x9a, 0xdb, 0xc0, 0xfe, 0x78, 0xcd, 0x5a, 0xf4,
	0x1f, 0xdd, 0xa8, 0x33, 0x88, 0x07, 0xc7, 0x31, 0xb1, 0x12, 0x10, 0x59, 0x27, 0x80, 0xec, 0x5f,
	0x60, 0x51, 0x7f, 0xa9, 0x19, 0xb5, 0x4a, 0x0d, 0x2d, 0xe5, 0x7a, 0x9f, 0x93, 0xc9, 0x9c, 0xef,
	0xa0, 0xe0, 0x3b, 0x4d, 0xae, 0x2a, 0xf5, 0xb0, 0xc8, 0xeb, 0xbb, 0x3c, 0x83, 0x53, 0x99, 0x61,
	0x17, 0x2b, 0x04, 0x7e, 0xba, 0x77, 0xd6, 0x26, 0xe1, 0x69, 0x14, 0x63, 0x55, 0x21, 0x0c, 0x7d,
} ;

// times 2 in the GF(2^8)
#define f2(x)   (((x) & 0x80) ? (x << 1) ^ WPOLY : x << 1)
#define d2(x)  (((x) >> 1) ^ ((x) & 1 ? DPOLY : 0))

static byte s_box (byte x)
{
	//  return fwd_affine (pgm_read_byte (&inv [x])) ;
	return pgm_read_byte (& s_fwd [x]) ;
}

// Inverse Sbox
static byte is_box (byte x)
{
	// return pgm_read_byte (&inv [inv_affine (x)]) ;
	return pgm_read_byte (& s_inv [x]) ;
}


static void xor_block (byte * d, byte * s)
{
	for (byte i = 0 ; i < N_BLOCK ; i += 4) {
		*d++ ^= *s++ ;  // some unrolling
		*d++ ^= *s++ ;
		*d++ ^= *s++ ;
		*d++ ^= *s++ ;
	}
}

static void copy_and_key (byte * d, byte * s, byte * k)
{
	for (byte i = 0 ; i < N_BLOCK ; i += 4) {
		*d++ = *s++ ^ *k++ ;  // some unrolling
		*d++ = *s++ ^ *k++ ;
		*d++ = *s++ ^ *k++ ;
		*d++ = *s++ ^ *k++ ;
	}
}

// #define add_round_key(d, k) xor_block (d, k)

/* SUB ROW PHASE */

static void shift_sub_rows (byte st [N_BLOCK])
{
	st [0] = s_box (st [0]) ;
	st [4]  = s_box (st [4]) ;
	st [8] = s_box (st [8]) ;
	st [12] = s_box (st [12]) ;

	byte tt = st [1] ;
	st [1] = s_box (st [5]) ;
	st [5]  = s_box (st [9]) ;
	st [9] = s_box (st [13]) ;
	st [13] = s_box (tt) ;

	tt = st[2] ;
	st [2] = s_box (st [10]) ;
	st [10] = s_box (tt) ;
	tt = st[6] ;
	st [6] = s_box (st [14]) ;
	st [14] = s_box (tt) ;

	tt = st[15] ;
	st [15] = s_box (st [11]) ;
	st [11] = s_box (st [7]) ;
	st [7]  = s_box (st [3]) ;
	st [3]  = s_box (tt) ;
}

static void inv_shift_sub_rows (byte st[N_BLOCK])
{
	st [0] = is_box (st[0]) ;
	st [4] = is_box (st [4]);
	st [8] = is_box (st[8]) ;
	st [12] = is_box (st [12]);

	byte tt = st[13] ;
	st [13] = is_box (st [9]) ;
	st [9] = is_box (st [5]) ;
	st [5]  = is_box (st [1]) ;
	st [1] = is_box (tt) ;

	tt = st [2] ;
	st [2] = is_box (st [10]) ;
	st [10] = is_box (tt) ;
	tt = st [6] ;
	st [6] = is_box (st [14]) ;
	st [14] = is_box (tt) ;

	tt = st [3] ;
	st [3]  = is_box (st [7])  ;
	st [7]  = is_box (st [11]) ;
	st [11] = is_box (st [15]) ;
	st [15] = is_box (tt) ;
}

/* SUB COLUMNS PHASE */

static void mix_sub_columns (byte dt[N_BLOCK], byte st[N_BLOCK])
{
	byte j = 5 ;
	byte k = 10 ;
	byte l = 15 ;
	for (byte i = 0 ; i < N_BLOCK ; i += N_COL) {
		byte a = st [i] ;
		byte b = st [j] ;
		j = (j+N_COL) & 15 ;
		byte c = st [k] ;
		k = (k+N_COL) & 15 ;
		byte d = st [l] ;
		l = (l+N_COL) & 15 ;
		byte a1 = s_box (a), b1 = s_box (b), c1 = s_box (c), d1 = s_box (d) ;
		byte a2 = f2(a1),    b2 = f2(b1),    c2 = f2(c1),    d2 = f2(d1) ;
		dt[i]   = a2     ^  b2^b1  ^  c1     ^  d1 ;
		dt[i+1] = a1     ^  b2     ^  c2^c1  ^  d1 ;
		dt[i+2] = a1     ^  b1     ^  c2     ^  d2^d1 ;
		dt[i+3] = a2^a1  ^  b1     ^  c1     ^  d2 ;
	}
}

static void inv_mix_sub_columns (byte dt[N_BLOCK], byte st[N_BLOCK])
{
	for (byte i = 0 ; i < N_BLOCK ; i += N_COL) {
		byte a1 = st [i] ;
		byte b1 = st [i+1] ;
		byte c1 = st [i+2] ;
		byte d1 = st [i+3] ;
		byte a2 = f2(a1), b2 = f2(b1), c2 = f2(c1), d2 = f2(d1) ;
		byte a4 = f2(a2), b4 = f2(b2), c4 = f2(c2), d4 = f2(d2) ;
		byte a8 = f2(a4), b8 = f2(b4), c8 = f2(c4), d8 = f2(d4) ;
		byte a9 = a8 ^ a1,b9 = b8 ^ b1,c9 = c8 ^ c1,d9 = d8 ^ d1 ;
		byte ac = a8 ^ a4,bc = b8 ^ b4,cc = c8 ^ c4,dc = d8 ^ d4 ;

		dt[i]         = is_box (ac^a2  ^  b9^b2  ^  cc^c1  ^  d9) ;
		dt[(i+5)&15]  = is_box (a9     ^  bc^b2  ^  c9^c2  ^  dc^d1) ;
		dt[(i+10)&15] = is_box (ac^a1  ^  b9     ^  cc^c2  ^  d9^d2) ;
		dt[(i+15)&15] = is_box (a9^a2  ^  bc^b1  ^  c9     ^  dc^d2) ;
	}
}

/******************************************************************************/

AES::AES()
{
	byte ar_iv[8] = { 0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x01 };
	IVC = 0x01;
	round = 0;
	pad = 0;
	size = 0;
	memset(key_sched, 0, KEY_SCHEDULE_BYTES);
	memcpy(iv,ar_iv,8);
	memcpy(iv+8,ar_iv,8);
	arr_pad[0] = 0x01;
	arr_pad[1] = 0x02;
	arr_pad[2] = 0x03;
	arr_pad[3] = 0x04;
	arr_pad[4] = 0x05;
	arr_pad[5] = 0x06;
	arr_pad[6] = 0x07;
	arr_pad[7] = 0x08;
	arr_pad[8] = 0x09;
	arr_pad[9] = 0x0a;
	arr_pad[10] = 0x0b;
	arr_pad[11] = 0x0c;
	arr_pad[12] = 0x0d;
	arr_pad[13] = 0x0e;
	arr_pad[14] = 0x0f;
}

/******************************************************************************/

byte AES::set_key (byte key [], int keylen)
{
	byte hi ;
	switch (keylen) {
	case 16:
	case 128:
		keylen = 16; // 10 rounds
		round = 10 ;
		break;
	case 24:
	case 192:
		keylen = 24; // 12 rounds
		round = 12 ;
		break;
	case 32:
	case 256:
		keylen = 32; // 14 rounds
		round = 14 ;
		break;
	default:
		round = 0;
		return AES_FAILURE;
	}
	hi = (round + 1) << 4 ;
	copy_n_bytes (key_sched, key, keylen) ;
	byte t[4] ;
	byte next = keylen ;
	for (byte cc = keylen, rc = 1 ; cc < hi ; cc += N_COL) {
		for (byte i = 0 ; i < N_COL ; i++) {
			t[i] = key_sched [cc-4+i] ;
		}
		if (cc == next) {
			next += keylen ;
			byte ttt = t[0] ;
			t[0] = s_box (t[1]) ^ rc ;
			t[1] = s_box (t[2]) ;
			t[2] = s_box (t[3]) ;
			t[3] = s_box (ttt) ;
			rc = f2 (rc) ;
		} else if (keylen == 32 && (cc & 31) == 16) {
			for (byte i = 0 ; i < 4 ; i++) {
				t[i] = s_box (t[i]) ;
			}
		}
		byte tt = cc - keylen ;
		for (byte i = 0 ; i < N_COL ; i++) {
			key_sched [cc + i] = key_sched [tt + i] ^ t[i] ;
		}
	}
	return AES_SUCCESS ;
}

/******************************************************************************/

void AES::clean ()
{
	for (byte i = 0 ; i < KEY_SCHEDULE_BYTES ; i++) {
		key_sched [i] = 0 ;
	}
	round = 0 ;
}

/******************************************************************************/

void AES::copy_n_bytes (byte * d, byte * s, byte nn)
{
	while (nn >= 4) {
		*d++ = *s++ ;  // some unrolling
		*d++ = *s++ ;
		*d++ = *s++ ;
		*d++ = *s++ ;
		nn -= 4 ;
	}
	while (nn--) {
		*d++ = *s++ ;
	}
}

/******************************************************************************/

byte AES::encrypt (byte plain [N_BLOCK], byte cipher [N_BLOCK])
{
	if (round) {
		byte s1 [N_BLOCK], r ;
		copy_and_key (s1, plain, (byte*) (key_sched)) ;

		for (r = 1 ; r < round ; r++) {
			byte s2 [N_BLOCK] ;
			mix_sub_columns (s2, s1) ;
			copy_and_key (s1, s2, (byte*) (key_sched + r * N_BLOCK)) ;
		}
		shift_sub_rows (s1) ;
		copy_and_key (cipher, s1, (byte*) (key_sched + r * N_BLOCK)) ;
	} else {
		return AES_FAILURE ;
	}
	return AES_SUCCESS ;
}

/******************************************************************************/

byte AES::cbc_encrypt (byte * plain, byte * cipher, int n_block, byte iv [N_BLOCK])
{
	while (n_block--) {
		xor_block (iv, plain) ;
		if (encrypt (iv, iv) != AES_SUCCESS) {
			return AES_FAILURE ;
		}
		copy_n_bytes (cipher, iv, N_BLOCK) ;
		plain  += N_BLOCK ;
		cipher += N_BLOCK ;
	}
	return AES_SUCCESS ;
}

/******************************************************************************/

byte AES::cbc_encrypt (byte * plain, byte * cipher, int n_block)
{
	while (n_block--) {
		xor_block (iv, plain) ;
		if (encrypt (iv, iv) != AES_SUCCESS) {
			return AES_FAILURE ;
		}
		copy_n_bytes (cipher, iv, N_BLOCK) ;
		plain  += N_BLOCK ;
		cipher += N_BLOCK ;
	}
	return AES_SUCCESS ;
}

/******************************************************************************/

byte AES::decrypt (byte plain [N_BLOCK], byte cipher [N_BLOCK])
{
	if (round) {
		byte s1 [N_BLOCK] ;
		copy_and_key (s1, plain, (byte*) (key_sched + round * N_BLOCK)) ;
		inv_shift_sub_rows (s1) ;

		for (byte r = round ; --r ; ) {
			byte s2 [N_BLOCK] ;
			copy_and_key (s2, s1, (byte*) (key_sched + r * N_BLOCK)) ;
			inv_mix_sub_columns (s1, s2) ;
		}
		copy_and_key (cipher, s1, (byte*) (key_sched)) ;
	} else {
		return AES_FAILURE ;
	}
	return AES_SUCCESS ;
}

/******************************************************************************/

byte AES::cbc_decrypt (byte * cipher, byte * plain, int n_block, byte iv [N_BLOCK])
{
	while (n_block--) {
		byte tmp [N_BLOCK] ;
		copy_n_bytes (tmp, cipher, N_BLOCK) ;
		if (decrypt (cipher, plain) != AES_SUCCESS) {
			return AES_FAILURE ;
		}
		xor_block (plain, iv) ;
		copy_n_bytes (iv, tmp, N_BLOCK) ;
		plain  += N_BLOCK ;
		cipher += N_BLOCK;
	}
	return AES_SUCCESS ;
}

/******************************************************************************/

byte AES::cbc_decrypt (byte * cipher, byte * plain, int n_block)
{
	while (n_block--) {
		byte tmp [N_BLOCK] ;
		copy_n_bytes (tmp, cipher, N_BLOCK) ;
		if (decrypt (cipher, plain) != AES_SUCCESS) {
			return AES_FAILURE ;
		}
		xor_block (plain, iv) ;
		copy_n_bytes (iv, tmp, N_BLOCK) ;
		plain  += N_BLOCK ;
		cipher += N_BLOCK;
	}
	return AES_SUCCESS ;
}

/*****************************************************************************/

void AES::set_IV(unsigned long long int IVCl)
{
	memcpy(iv,&IVCl,8);
	memcpy(iv+8,&IVCl,8);
	IVC = IVCl;
}

/******************************************************************************/

void AES::iv_inc()
{
	IVC += 1;
	memcpy(iv,&IVC,8);
	memcpy(iv+8,&IVC,8);
}

/******************************************************************************/

int AES::get_size()
{
	return size;
}

/******************************************************************************/

void AES::set_size(int sizel)
{
	size = sizel;
}


/******************************************************************************/

void AES::get_IV(byte *out)
{
	memcpy(out,&IVC,8);
	memcpy(out+8,&IVC,8);
}

/******************************************************************************/

void AES::calc_size_n_pad(int p_size)
{
	int s_of_p = p_size - 1;
	if ( s_of_p % N_BLOCK == 0) {
		size = s_of_p;
	} else {
		size = s_of_p +  (N_BLOCK-(s_of_p % N_BLOCK));
	}
	pad = size - s_of_p;
}

/******************************************************************************/

void AES::padPlaintext(void* in,byte* out)
{
	memcpy(out,in,size);
	for (int i = size-pad; i < size; i++) {
		;
		out[i] = arr_pad[pad - 1];
	}
}

/******************************************************************************/

bool AES::CheckPad(byte* in,int lsize)
{
	if (in[lsize-1] <= 0x0f) {
		int lpad = (int)in[lsize-1];
		for (int i = lsize - 1; i >= lsize-lpad; i--) {
			if (arr_pad[lpad - 1] != in[i]) {
				return false;
			}
		}
	} else {
		return true;
	}
	return true;
}

/******************************************************************************/

void AES::printArray(byte output[],bool p_pad)
{
	uint8_t i,j;
	uint8_t loops = size/N_BLOCK;
	uint8_t outp = N_BLOCK;
	for (j = 0; j < loops; j += 1) {
		if (p_pad && (j == (loops  - 1)) ) {
			outp = N_BLOCK - pad;
		}
		for (i = 0; i < outp; i++) {
			printf_P(PSTR("%c"),output[j*N_BLOCK + i]);
		}
	}
	printf_P(PSTR("\n"));
}

/******************************************************************************/

void AES::printArray(byte output[],int sizel)
{
	for (int i = 0; i < sizel; i++) {
		printf_P(PSTR("%x"),output[i]);
	}
	printf_P(PSTR("\n"));
}


/******************************************************************************/

void AES::do_aes_encrypt(byte *plain,int size_p,byte *cipher,byte *key, int bits,
                         byte ivl [N_BLOCK])
{
	calc_size_n_pad(size_p);
	byte plain_p[get_size()];
	padPlaintext(plain,plain_p);
	int blocks = get_size() / N_BLOCK;
	set_key (key, bits) ;
	cbc_encrypt (plain_p, cipher, blocks, ivl);
}

/******************************************************************************/

void AES::do_aes_encrypt(byte *plain,int size_p,byte *cipher,byte *key, int bits)
{
	calc_size_n_pad(size_p);
	byte plain_p[get_size()];
	padPlaintext(plain,plain_p);
	int blocks = get_size() / N_BLOCK;
	set_key (key, bits) ;
	cbc_encrypt (plain_p, cipher, blocks);
}

/******************************************************************************/

void AES::do_aes_decrypt(byte *cipher,int size_c,byte *plain,byte *key, int bits,
                         byte ivl [N_BLOCK])
{
	set_size(size_c);
	int blocks = size_c / N_BLOCK;
	set_key (key, bits);
	cbc_decrypt (cipher,plain, blocks, ivl);
}

/******************************************************************************/

void AES::do_aes_decrypt(byte *cipher,int size_c,byte *plain,byte *key, int bits)
{
	set_size(size_c);
	int blocks = size_c / N_BLOCK;
	set_key (key, bits);
	cbc_decrypt (cipher,plain, blocks);
}


/******************************************************************************/

#if defined(AES_LINUX)
double AES::millis()
{
	gettimeofday(&tv, NULL);
	return (tv.tv_sec + 0.000001 * tv.tv_usec);
}
#endif