/* 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"
#include "string.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 t = 0;
for (bit = 0; bit < 8; ++bit) {
uint8_t 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;
}
}
/******************************************************************************/