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[proxmark3-svn] / armsrc / des.c

/* des.c */
/*
    This file is part of the ARM-Crypto-Lib.
    Copyright (C) 2006-2010  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     des.c
 * \author   Daniel Otte
 * \email    daniel.otte@rub.de
 * \date     2007-06-16
 * \brief    DES and EDE-DES implementation
 * \license	 GPLv3 or later
 * 
 */

#include "des.h"

const uint8_t sbox[256]  = {
  /* S-box 1 */
  0xE4, 0xD1, 0x2F, 0xB8, 0x3A, 0x6C, 0x59, 0x07,
  0x0F, 0x74, 0xE2, 0xD1, 0xA6, 0xCB, 0x95, 0x38,
  0x41, 0xE8, 0xD6, 0x2B, 0xFC, 0x97, 0x3A, 0x50,
  0xFC, 0x82, 0x49, 0x17, 0x5B, 0x3E, 0xA0, 0x6D,
  /* S-box 2 */
  0xF1, 0x8E, 0x6B, 0x34, 0x97, 0x2D, 0xC0, 0x5A,
  0x3D, 0x47, 0xF2, 0x8E, 0xC0, 0x1A, 0x69, 0xB5,
  0x0E, 0x7B, 0xA4, 0xD1, 0x58, 0xC6, 0x93, 0x2F,
  0xD8, 0xA1, 0x3F, 0x42, 0xB6, 0x7C, 0x05, 0xE9,
  /* S-box 3 */
  0xA0, 0x9E, 0x63, 0xF5, 0x1D, 0xC7, 0xB4, 0x28,
  0xD7, 0x09, 0x34, 0x6A, 0x28, 0x5E, 0xCB, 0xF1,
  0xD6, 0x49, 0x8F, 0x30, 0xB1, 0x2C, 0x5A, 0xE7,
  0x1A, 0xD0, 0x69, 0x87, 0x4F, 0xE3, 0xB5, 0x2C,
  /* S-box 4 */
  0x7D, 0xE3, 0x06, 0x9A, 0x12, 0x85, 0xBC, 0x4F,
  0xD8, 0xB5, 0x6F, 0x03, 0x47, 0x2C, 0x1A, 0xE9,
  0xA6, 0x90, 0xCB, 0x7D, 0xF1, 0x3E, 0x52, 0x84,
  0x3F, 0x06, 0xA1, 0xD8, 0x94, 0x5B, 0xC7, 0x2E,
  /* S-box 5 */
  0x2C, 0x41, 0x7A, 0xB6, 0x85, 0x3F, 0xD0, 0xE9,
  0xEB, 0x2C, 0x47, 0xD1, 0x50, 0xFA, 0x39, 0x86,
  0x42, 0x1B, 0xAD, 0x78, 0xF9, 0xC5, 0x63, 0x0E,
  0xB8, 0xC7, 0x1E, 0x2D, 0x6F, 0x09, 0xA4, 0x53,
  /* S-box 6 */
  0xC1, 0xAF, 0x92, 0x68, 0x0D, 0x34, 0xE7, 0x5B,
  0xAF, 0x42, 0x7C, 0x95, 0x61, 0xDE, 0x0B, 0x38,
  0x9E, 0xF5, 0x28, 0xC3, 0x70, 0x4A, 0x1D, 0xB6,
  0x43, 0x2C, 0x95, 0xFA, 0xBE, 0x17, 0x60, 0x8D,
  /* S-box 7 */
  0x4B, 0x2E, 0xF0, 0x8D, 0x3C, 0x97, 0x5A, 0x61,
  0xD0, 0xB7, 0x49, 0x1A, 0xE3, 0x5C, 0x2F, 0x86,
  0x14, 0xBD, 0xC3, 0x7E, 0xAF, 0x68, 0x05, 0x92,
  0x6B, 0xD8, 0x14, 0xA7, 0x95, 0x0F, 0xE2, 0x3C,
  /* S-box 8 */
  0xD2, 0x84, 0x6F, 0xB1, 0xA9, 0x3E, 0x50, 0xC7,
  0x1F, 0xD8, 0xA3, 0x74, 0xC5, 0x6B, 0x0E, 0x92,
  0x7B, 0x41, 0x9C, 0xE2, 0x06, 0xAD, 0xF3, 0x58,
  0x21, 0xE7, 0x4A, 0x8D, 0xFC, 0x90, 0x35, 0x6B
};

const uint8_t e_permtab[] ={
	 4,  6, 					/* 4 bytes in 6 bytes out*/
	32,  1,  2,  3,  4,  5,
	 4,  5,  6,  7,  8,  9,
	 8,  9, 10, 11, 12, 13,
	12, 13, 14, 15, 16, 17,
	16, 17, 18, 19, 20, 21,
	20, 21, 22, 23, 24, 25,
	24, 25, 26, 27, 28, 29,
	28, 29, 30, 31, 32,  1
};

const uint8_t p_permtab[] ={
	 4,  4,						/* 32 bit -> 32 bit */
	16,  7, 20, 21,
	29, 12, 28, 17,
	 1, 15, 23, 26,
	 5, 18, 31, 10,
	 2,  8, 24, 14,
	32, 27,  3,  9,
	19, 13, 30,  6,
	22, 11,  4, 25
};

const uint8_t ip_permtab[] ={
	 8,  8,						/* 64 bit -> 64 bit */
	58, 50, 42, 34, 26, 18, 10, 2,
	60, 52, 44, 36, 28, 20, 12, 4,
	62, 54, 46, 38, 30, 22, 14, 6,
	64, 56, 48, 40, 32, 24, 16, 8,
	57, 49, 41, 33, 25, 17,  9, 1,
	59, 51, 43, 35, 27, 19, 11, 3,
	61, 53, 45, 37, 29, 21, 13, 5,
	63, 55, 47, 39, 31, 23, 15, 7
};

const uint8_t inv_ip_permtab[] ={
	 8, 8,						/* 64 bit -> 64 bit */
	40, 8, 48, 16, 56, 24, 64, 32,
	39, 7, 47, 15, 55, 23, 63, 31,
	38, 6, 46, 14, 54, 22, 62, 30,
	37, 5, 45, 13, 53, 21, 61, 29,
	36, 4, 44, 12, 52, 20, 60, 28,
	35, 3, 43, 11, 51, 19, 59, 27,
	34, 2, 42, 10, 50, 18, 58, 26,
	33, 1, 41,  9, 49, 17, 57, 25
};

const uint8_t pc1_permtab[] ={
	 8,  7, 					/* 64 bit -> 56 bit*/
	57, 49, 41, 33, 25, 17,  9,
	 1, 58, 50, 42, 34, 26, 18,
	10,  2, 59, 51, 43, 35, 27,
	19, 11,  3, 60, 52, 44, 36,
	63, 55, 47, 39, 31, 23, 15,
	 7, 62, 54, 46, 38, 30, 22,
	14,  6, 61, 53, 45, 37, 29,
	21, 13,  5, 28, 20, 12,  4
};

const uint8_t pc2_permtab[] ={
	 7,	 6, 					/* 56 bit -> 48 bit */
	14, 17, 11, 24,  1,  5,
	 3, 28, 15,  6, 21, 10,
	23, 19, 12,  4, 26,  8,
	16,  7, 27, 20, 13,  2,
	41, 52, 31, 37, 47, 55,
	30, 40, 51, 45, 33, 48,
	44, 49, 39, 56, 34, 53,
	46, 42, 50, 36, 29, 32
};

const uint8_t splitin6bitword_permtab[] = {
	 8,  8, 					/* 64 bit -> 64 bit */
	64, 64,  1,  6,  2,  3,  4,  5, 
	64, 64,  7, 12,  8,  9, 10, 11, 
	64, 64, 13, 18, 14, 15, 16, 17, 
	64, 64, 19, 24, 20, 21, 22, 23, 
	64, 64, 25, 30, 26, 27, 28, 29, 
	64, 64, 31, 36, 32, 33, 34, 35, 
	64, 64, 37, 42, 38, 39, 40, 41, 
	64, 64, 43, 48, 44, 45, 46, 47 
};

const uint8_t shiftkey_permtab[] = {
	 7,  7, 					/* 56 bit -> 56 bit */
	 2,  3,  4,  5,  6,  7,  8,  9,
	10, 11, 12, 13, 14, 15, 16, 17,
	18, 19, 20, 21, 22, 23, 24, 25, 
	26, 27, 28,  1, 
	30, 31, 32, 33, 34, 35, 36, 37, 
	38, 39, 40, 41, 42, 43, 44, 45, 
	46, 47, 48, 49, 50, 51, 52, 53, 
	54, 55, 56, 29
};

const uint8_t shiftkeyinv_permtab[] = {
	 7,  7,
	28,  1,  2,  3,  4,  5,  6,  7,
	 8,  9, 10, 11, 12, 13, 14, 15,
	16, 17, 18, 19, 20, 21, 22, 23,
	24, 25, 26, 27,
	56, 29, 30, 31, 32, 33, 34, 35, 
	36, 37, 38, 39, 40, 41, 42, 43, 
	44, 45, 46, 47, 48, 49, 50, 51, 
	52, 53, 54, 55
};

/*
1 0
1 0
2 1
2 1
2 1
2 1
2 1
2 1
----
1 0
2 1
2 1
2 1
2 1
2 1
2 1
1 0
*/
#define ROTTABLE      0x7EFC 
#define ROTTABLE_INV  0x3F7E
/******************************************************************************/

void permute(const uint8_t *ptable, const uint8_t *in, uint8_t *out){
	uint8_t ob; /* in-bytes and out-bytes */
	uint8_t byte, bit; /* counter for bit and byte */
	ob = ptable[1];
	ptable = &(ptable[2]);
	for(byte=0; byte<ob; ++byte){
		uint8_t x,t=0;
		for(bit=0; bit<8; ++bit){
			x = *ptable++ - 1;
				t<<=1;
			if((in[x/8]) & (0x80>>(x%8)) ){
				t|=0x01;
			}
		}
		out[byte]=t;
	}
}

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

void changeendian32(uint32_t * a){
	*a = (*a & 0x000000FF) << 24 |
		 (*a & 0x0000FF00) <<  8 |
		 (*a & 0x00FF0000) >>  8 |
		 (*a & 0xFF000000) >> 24;
}

/******************************************************************************/
static inline
void shiftkey(uint8_t *key){
	uint8_t k[7];
	memcpy(k, key, 7);
	permute((uint8_t*)shiftkey_permtab, k, key);	
}

/******************************************************************************/
static inline
void shiftkey_inv(uint8_t *key){
	uint8_t k[7];
	memcpy(k, key, 7);
	permute((uint8_t*)shiftkeyinv_permtab, k, key);
	
}

/******************************************************************************/
static inline
uint64_t splitin6bitwords(uint64_t a){
	uint64_t ret=0;
	a &= 0x0000ffffffffffffLL;
	permute((uint8_t*)splitin6bitword_permtab, (uint8_t*)&a, (uint8_t*)&ret);	
	return ret;
}

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

static inline
uint8_t substitute(uint8_t a, uint8_t * sbp){
	uint8_t x;	
	x = sbp[a>>1];
	x = (a&1)?x&0x0F:x>>4;
	return x;
	
}

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

uint32_t des_f(uint32_t r, uint8_t* kr){
	uint8_t i;
	uint32_t t=0,ret;
	uint64_t data;
	uint8_t *sbp; /* sboxpointer */ 
	permute((uint8_t*)e_permtab, (uint8_t*)&r, (uint8_t*)&data);
	for(i=0; i<6; ++i)
		((uint8_t*)&data)[i] ^= kr[i];
	
	/* Sbox substitution */
	data = splitin6bitwords(data);
	sbp=(uint8_t*)sbox;
	for(i=0; i<8; ++i){
		uint8_t x;
		x = substitute(((uint8_t*)&data)[i], sbp);
		t<<=4;
		t |= x;
		sbp += 32;
	}
	changeendian32(&t);
		
	permute((uint8_t*)p_permtab,(uint8_t*)&t, (uint8_t*)&ret);

	return ret;
}

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

typedef struct {
	union {
		uint8_t  v8[8];
		uint32_t v32[2];
	} d;
} data_t;
#define R (data.d.v32[1])
#define L (data.d.v32[0])

void des_enc(void* out, const void* in, const void* key){

	uint8_t kr[6], k[7];
	uint8_t i;
	data_t data;
	
	permute((uint8_t*)ip_permtab, (uint8_t*)in, data.d.v8);
	permute((uint8_t*)pc1_permtab, (const uint8_t*)key, k);

	for(i=0; i<8; ++i){
		shiftkey(k);
		if(ROTTABLE&((1<<((i<<1)+0))) )
			shiftkey(k);
		permute((uint8_t*)pc2_permtab, k, kr);
		L ^= des_f(R, kr);
		
		shiftkey(k);
		if(ROTTABLE&((1<<((i<<1)+1))) )
			shiftkey(k);
		permute((uint8_t*)pc2_permtab, k, kr);
		R ^= des_f(L, kr);

	}
	/* L <-> R*/
	R ^= L;
	L ^= R;
	R ^= L;
	
	permute((uint8_t*)inv_ip_permtab, data.d.v8, (uint8_t*)out);
}

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

void des_dec(void* out, const void* in, const uint8_t* key){

	uint8_t kr[6],k[7];
	int8_t i;
	data_t data;
	
	permute((uint8_t*)ip_permtab, (uint8_t*)in, data.d.v8);
	permute((uint8_t*)pc1_permtab, (const uint8_t*)key, k);
	for(i=7; i>=0; --i){
		
		permute((uint8_t*)pc2_permtab, k, kr);
		L ^= des_f(R, kr);
		shiftkey_inv(k);
		if(ROTTABLE&((1<<((i<<1)+1))) ){
			shiftkey_inv(k);
		}

		permute((uint8_t*)pc2_permtab, k, kr);
		R ^= des_f(L, kr);
		shiftkey_inv(k);
		if(ROTTABLE&((1<<((i<<1)+0))) ){
			shiftkey_inv(k);
		}

	}
	/* L <-> R*/
	R ^= L;
	L ^= R;
	R ^= L;
	
	permute((uint8_t*)inv_ip_permtab, data.d.v8, (uint8_t*)out);
}

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

void tdes_enc(void* out, void* in, const void* key){
	des_enc(out,  in, (uint8_t*)key + 0);
	des_dec(out, out, (uint8_t*)key + 8);
	des_enc(out, out, (uint8_t*)key +16);
}

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

void tdes_dec(void* out, void* in, const uint8_t* key){
	des_dec(out,  in, (uint8_t*)key +16);
	des_enc(out, out, (uint8_t*)key + 8);
	des_dec(out, out, (uint8_t*)key + 0);
}

 void tdes_2key_enc(void* out, const void* in, size_t length, const void* key, unsigned char iv[8]){

	if( length % 8 ) return; 

	uint8_t i;
	uint8_t* tin = (uint8_t*) in;
	uint8_t* tout = (uint8_t*) out;
	
	while( length > 0 )
	{
		for( i = 0; i < 8; i++ )
				tout[i] = (unsigned char)( tin[i] ^ iv[i] );
		
		des_enc(tout,  tin, (uint8_t*)key + 0);
		des_dec(tout, tout, (uint8_t*)key + 8);
		des_enc(tout, tout, (uint8_t*)key + 0);
		
		memcpy( iv, tout, 8 );
		
		tin  += 8;
		tout += 8;
		length -= 8;
	}
 }
 
 void tdes_2key_dec(void* out, const void* in, size_t length, const void* key, unsigned char iv[8]){
	
	if( length % 8 ) return; 

	uint8_t i;
	unsigned char temp[8];
	uint8_t* tin = (uint8_t*) in;
	uint8_t* tout = (uint8_t*) out;
	
	while( length > 0 )
	{
		memcpy( temp, tin, 8 );
		
		des_dec(tout,  tin, (uint8_t*)key + 0);
		des_enc(tout, tout, (uint8_t*)key + 8);
		des_dec(tout, tout, (uint8_t*)key + 0);	 	 

		for( i = 0; i < 8; i++ )
			tout[i] = (unsigned char)( tout[i] ^ iv[i] );

		memcpy( iv, temp, 8 );
		
		tin  += 8;
		tout += 8;
		length -= 8;
	}
 }


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