src/crypto/des-internal.c

/*
 * DES and 3DES-EDE ciphers
 *
 * Modifications to LibTomCrypt implementation:
 * Copyright (c) 2006-2009, Jouni Malinen <j@w1.fi>
 *
 * This software may be distributed under the terms of the BSD license.
 * See README for more details.
 */

#include "includes.h"

#include "common.h"
#include "crypto.h"
#include "des_i.h"

/*
 * This implementation is based on a DES implementation included in
 * LibTomCrypt. The version here is modified to fit in wpa_supplicant/hostapd
 * coding style.
 */

/* LibTomCrypt, modular cryptographic library -- Tom St Denis
 *
 * LibTomCrypt is a library that provides various cryptographic
 * algorithms in a highly modular and flexible manner.
 *
 * The library is free for all purposes without any express
 * guarantee it works.
 *
 * Tom St Denis, tomstdenis@gmail.com, http://libtomcrypt.com
 */

/**
  DES code submitted by Dobes Vandermeer
*/

#define ROLc(x, y) \
	((((unsigned long) (x) << (unsigned long) ((y) & 31)) | \
	  (((unsigned long) (x) & 0xFFFFFFFFUL) >> \
	   (unsigned long) (32 - ((y) & 31)))) & 0xFFFFFFFFUL)
#define RORc(x, y) \
	(((((unsigned long) (x) & 0xFFFFFFFFUL) >> \
	   (unsigned long) ((y) & 31)) | \
	  ((unsigned long) (x) << (unsigned long) (32 - ((y) & 31)))) & \
	 0xFFFFFFFFUL)


static const u32 bytebit[8] =
{
	0200, 0100, 040, 020, 010, 04, 02, 01
};

static const u32 bigbyte[24] =
{
	0x800000UL,  0x400000UL,  0x200000UL,  0x100000UL,
	0x80000UL,   0x40000UL,   0x20000UL,   0x10000UL,
	0x8000UL,    0x4000UL,    0x2000UL,    0x1000UL,
	0x800UL,     0x400UL,     0x200UL,     0x100UL,
	0x80UL,      0x40UL,      0x20UL,      0x10UL,
	0x8UL,       0x4UL,       0x2UL,       0x1L
};

/* Use the key schedule specific in the standard (ANSI X3.92-1981) */

static const u8 pc1[56] = {
	56, 48, 40, 32, 24, 16,  8,  0, 57, 49, 41, 33, 25, 17,
	 9,  1, 58, 50, 42, 34, 26, 18, 10,  2, 59, 51, 43, 35,
	62, 54, 46, 38, 30, 22, 14,  6, 61, 53, 45, 37, 29, 21,
	13,  5, 60, 52, 44, 36, 28, 20, 12,  4, 27, 19, 11,  3
};

static const u8 totrot[16] = {
	1,   2,  4,  6,
	8,  10, 12, 14,
	15, 17, 19, 21,
	23, 25, 27, 28
};

static const u8 pc2[48] = {
	13, 16, 10, 23,  0,  4,      2, 27, 14,  5, 20,  9,
	22, 18, 11,  3, 25,  7,     15,  6, 26, 19, 12,  1,
	40, 51, 30, 36, 46, 54,     29, 39, 50, 44, 32, 47,
	43, 48, 38, 55, 33, 52,     45, 41, 49, 35, 28, 31
};


static const u32 SP1[64] =
{
	0x01010400UL, 0x00000000UL, 0x00010000UL, 0x01010404UL,
	0x01010004UL, 0x00010404UL, 0x00000004UL, 0x00010000UL,
	0x00000400UL, 0x01010400UL, 0x01010404UL, 0x00000400UL,
	0x01000404UL, 0x01010004UL, 0x01000000UL, 0x00000004UL,
	0x00000404UL, 0x01000400UL, 0x01000400UL, 0x00010400UL,
	0x00010400UL, 0x01010000UL, 0x01010000UL, 0x01000404UL,
	0x00010004UL, 0x01000004UL, 0x01000004UL, 0x00010004UL,
	0x00000000UL, 0x00000404UL, 0x00010404UL, 0x01000000UL,
	0x00010000UL, 0x01010404UL, 0x00000004UL, 0x01010000UL,
	0x01010400UL, 0x01000000UL, 0x01000000UL, 0x00000400UL,
	0x01010004UL, 0x00010000UL, 0x00010400UL, 0x01000004UL,
	0x00000400UL, 0x00000004UL, 0x01000404UL, 0x00010404UL,
	0x01010404UL, 0x00010004UL, 0x01010000UL, 0x01000404UL,
	0x01000004UL, 0x00000404UL, 0x00010404UL, 0x01010400UL,
	0x00000404UL, 0x01000400UL, 0x01000400UL, 0x00000000UL,
	0x00010004UL, 0x00010400UL, 0x00000000UL, 0x01010004UL
};

static const u32 SP2[64] =
{
	0x80108020UL, 0x80008000UL, 0x00008000UL, 0x00108020UL,
	0x00100000UL, 0x00000020UL, 0x80100020UL, 0x80008020UL,
	0x80000020UL, 0x80108020UL, 0x80108000UL, 0x80000000UL,
	0x80008000UL, 0x00100000UL, 0x00000020UL, 0x80100020UL,
	0x00108000UL, 0x00100020UL, 0x80008020UL, 0x00000000UL,
	0x80000000UL, 0x00008000UL, 0x00108020UL, 0x80100000UL,
	0x00100020UL, 0x80000020UL, 0x00000000UL, 0x00108000UL,
	0x00008020UL, 0x80108000UL, 0x80100000UL, 0x00008020UL,
	0x00000000UL, 0x00108020UL, 0x80100020UL, 0x00100000UL,
	0x80008020UL, 0x80100000UL, 0x80108000UL, 0x00008000UL,
	0x80100000UL, 0x80008000UL, 0x00000020UL, 0x80108020UL,
	0x00108020UL, 0x00000020UL, 0x00008000UL, 0x80000000UL,
	0x00008020UL, 0x80108000UL, 0x00100000UL, 0x80000020UL,
	0x00100020UL, 0x80008020UL, 0x80000020UL, 0x00100020UL,
	0x00108000UL, 0x00000000UL, 0x80008000UL, 0x00008020UL,
	0x80000000UL, 0x80100020UL, 0x80108020UL, 0x00108000UL
};

static const u32 SP3[64] =
{
	0x00000208UL, 0x08020200UL, 0x00000000UL, 0x08020008UL,
	0x08000200UL, 0x00000000UL, 0x00020208UL, 0x08000200UL,
	0x00020008UL, 0x08000008UL, 0x08000008UL, 0x00020000UL,
	0x08020208UL, 0x00020008UL, 0x08020000UL, 0x00000208UL,
	0x08000000UL, 0x00000008UL, 0x08020200UL, 0x00000200UL,
	0x00020200UL, 0x08020000UL, 0x08020008UL, 0x00020208UL,
	0x08000208UL, 0x00020200UL, 0x00020000UL, 0x08000208UL,
	0x00000008UL, 0x08020208UL, 0x00000200UL, 0x08000000UL,
	0x08020200UL, 0x08000000UL, 0x00020008UL, 0x00000208UL,
	0x00020000UL, 0x08020200UL, 0x08000200UL, 0x00000000UL,
	0x00000200UL, 0x00020008UL, 0x08020208UL, 0x08000200UL,
	0x08000008UL, 0x00000200UL, 0x00000000UL, 0x08020008UL,
	0x08000208UL, 0x00020000UL, 0x08000000UL, 0x08020208UL,
	0x00000008UL, 0x00020208UL, 0x00020200UL, 0x08000008UL,
	0x08020000UL, 0x08000208UL, 0x00000208UL, 0x08020000UL,
	0x00020208UL, 0x00000008UL, 0x08020008UL, 0x00020200UL
};

static const u32 SP4[64] =
{
	0x00802001UL, 0x00002081UL, 0x00002081UL, 0x00000080UL,
	0x00802080UL, 0x00800081UL, 0x00800001UL, 0x00002001UL,
	0x00000000UL, 0x00802000UL, 0x00802000UL, 0x00802081UL,
	0x00000081UL, 0x00000000UL, 0x00800080UL, 0x00800001UL,
	0x00000001UL, 0x00002000UL, 0x00800000UL, 0x00802001UL,
	0x00000080UL, 0x00800000UL, 0x00002001UL, 0x00002080UL,
	0x00800081UL, 0x00000001UL, 0x00002080UL, 0x00800080UL,
	0x00002000UL, 0x00802080UL, 0x00802081UL, 0x00000081UL,
	0x00800080UL, 0x00800001UL, 0x00802000UL, 0x00802081UL,
	0x00000081UL, 0x00000000UL, 0x00000000UL, 0x00802000UL,
	0x00002080UL, 0x00800080UL, 0x00800081UL, 0x00000001UL,
	0x00802001UL, 0x00002081UL, 0x00002081UL, 0x00000080UL,
	0x00802081UL, 0x00000081UL, 0x00000001UL, 0x00002000UL,
	0x00800001UL, 0x00002001UL, 0x00802080UL, 0x00800081UL,
	0x00002001UL, 0x00002080UL, 0x00800000UL, 0x00802001UL,
	0x00000080UL, 0x00800000UL, 0x00002000UL, 0x00802080UL
};

static const u32 SP5[64] =
{
	0x00000100UL, 0x02080100UL, 0x02080000UL, 0x42000100UL,
	0x00080000UL, 0x00000100UL, 0x40000000UL, 0x02080000UL,
	0x40080100UL, 0x00080000UL, 0x02000100UL, 0x40080100UL,
	0x42000100UL, 0x42080000UL, 0x00080100UL, 0x40000000UL,
	0x02000000UL, 0x40080000UL, 0x40080000UL, 0x00000000UL,
	0x40000100UL, 0x42080100UL, 0x42080100UL, 0x02000100UL,
	0x42080000UL, 0x40000100UL, 0x00000000UL, 0x42000000UL,
	0x02080100UL, 0x02000000UL, 0x42000000UL, 0x00080100UL,
	0x00080000UL, 0x42000100UL, 0x00000100UL, 0x02000000UL,
	0x40000000UL, 0x02080000UL, 0x42000100UL, 0x40080100UL,
	0x02000100UL, 0x40000000UL, 0x42080000UL, 0x02080100UL,
	0x40080100UL, 0x00000100UL, 0x02000000UL, 0x42080000UL,
	0x42080100UL, 0x00080100UL, 0x42000000UL, 0x42080100UL,
	0x02080000UL, 0x00000000UL, 0x40080000UL, 0x42000000UL,
	0x00080100UL, 0x02000100UL, 0x40000100UL, 0x00080000UL,
	0x00000000UL, 0x40080000UL, 0x02080100UL, 0x40000100UL
};

static const u32 SP6[64] =
{
	0x20000010UL, 0x20400000UL, 0x00004000UL, 0x20404010UL,
	0x20400000UL, 0x00000010UL, 0x20404010UL, 0x00400000UL,
	0x20004000UL, 0x00404010UL, 0x00400000UL, 0x20000010UL,
	0x00400010UL, 0x20004000UL, 0x20000000UL, 0x00004010UL,
	0x00000000UL, 0x00400010UL, 0x20004010UL, 0x00004000UL,
	0x00404000UL, 0x20004010UL, 0x00000010UL, 0x20400010UL,
	0x20400010UL, 0x00000000UL, 0x00404010UL, 0x20404000UL,
	0x00004010UL, 0x00404000UL, 0x20404000UL, 0x20000000UL,
	0x20004000UL, 0x00000010UL, 0x20400010UL, 0x00404000UL,
	0x20404010UL, 0x00400000UL, 0x00004010UL, 0x20000010UL,
	0x00400000UL, 0x20004000UL, 0x20000000UL, 0x00004010UL,
	0x20000010UL, 0x20404010UL, 0x00404000UL, 0x20400000UL,
	0x00404010UL, 0x20404000UL, 0x00000000UL, 0x20400010UL,
	0x00000010UL, 0x00004000UL, 0x20400000UL, 0x00404010UL,
	0x00004000UL, 0x00400010UL, 0x20004010UL, 0x00000000UL,
	0x20404000UL, 0x20000000UL, 0x00400010UL, 0x20004010UL
};

static const u32 SP7[64] =
{
	0x00200000UL, 0x04200002UL, 0x04000802UL, 0x00000000UL,
	0x00000800UL, 0x04000802UL, 0x00200802UL, 0x04200800UL,
	0x04200802UL, 0x00200000UL, 0x00000000UL, 0x04000002UL,
	0x00000002UL, 0x04000000UL, 0x04200002UL, 0x00000802UL,
	0x04000800UL, 0x00200802UL, 0x00200002UL, 0x04000800UL,
	0x04000002UL, 0x04200000UL, 0x04200800UL, 0x00200002UL,
	0x04200000UL, 0x00000800UL, 0x00000802UL, 0x04200802UL,
	0x00200800UL, 0x00000002UL, 0x04000000UL, 0x00200800UL,
	0x04000000UL, 0x00200800UL, 0x00200000UL, 0x04000802UL,
	0x04000802UL, 0x04200002UL, 0x04200002UL, 0x00000002UL,
	0x00200002UL, 0x04000000UL, 0x04000800UL, 0x00200000UL,
	0x04200800UL, 0x00000802UL, 0x00200802UL, 0x04200800UL,
	0x00000802UL, 0x04000002UL, 0x04200802UL, 0x04200000UL,
	0x00200800UL, 0x00000000UL, 0x00000002UL, 0x04200802UL,
	0x00000000UL, 0x00200802UL, 0x04200000UL, 0x00000800UL,
	0x04000002UL, 0x04000800UL, 0x00000800UL, 0x00200002UL
};

static const u32 SP8[64] =
{
	0x10001040UL, 0x00001000UL, 0x00040000UL, 0x10041040UL,
	0x10000000UL, 0x10001040UL, 0x00000040UL, 0x10000000UL,
	0x00040040UL, 0x10040000UL, 0x10041040UL, 0x00041000UL,
	0x10041000UL, 0x00041040UL, 0x00001000UL, 0x00000040UL,
	0x10040000UL, 0x10000040UL, 0x10001000UL, 0x00001040UL,
	0x00041000UL, 0x00040040UL, 0x10040040UL, 0x10041000UL,
	0x00001040UL, 0x00000000UL, 0x00000000UL, 0x10040040UL,
	0x10000040UL, 0x10001000UL, 0x00041040UL, 0x00040000UL,
	0x00041040UL, 0x00040000UL, 0x10041000UL, 0x00001000UL,
	0x00000040UL, 0x10040040UL, 0x00001000UL, 0x00041040UL,
	0x10001000UL, 0x00000040UL, 0x10000040UL, 0x10040000UL,
	0x10040040UL, 0x10000000UL, 0x00040000UL, 0x10001040UL,
	0x00000000UL, 0x10041040UL, 0x00040040UL, 0x10000040UL,
	0x10040000UL, 0x10001000UL, 0x10001040UL, 0x00000000UL,
	0x10041040UL, 0x00041000UL, 0x00041000UL, 0x00001040UL,
	0x00001040UL, 0x00040040UL, 0x10000000UL, 0x10041000UL
};


static void cookey(const u32 *raw1, u32 *keyout)
{
	u32 *cook;
	const u32 *raw0;
	u32 dough[32];
	int i;

	cook = dough;
	for (i = 0; i < 16; i++, raw1++) {
		raw0 = raw1++;
		*cook    = (*raw0 & 0x00fc0000L) << 6;
		*cook   |= (*raw0 & 0x00000fc0L) << 10;
		*cook   |= (*raw1 & 0x00fc0000L) >> 10;
		*cook++ |= (*raw1 & 0x00000fc0L) >> 6;
		*cook    = (*raw0 & 0x0003f000L) << 12;
		*cook   |= (*raw0 & 0x0000003fL) << 16;
		*cook   |= (*raw1 & 0x0003f000L) >> 4;
		*cook++ |= (*raw1 & 0x0000003fL);
	}

	os_memcpy(keyout, dough, sizeof(dough));
}


static void deskey(const u8 *key, int decrypt, u32 *keyout)
{
	u32 i, j, l, m, n, kn[32];
	u8 pc1m[56], pcr[56];

	for (j = 0; j < 56; j++) {
		l = (u32) pc1[j];
		m = l & 7;
		pc1m[j] = (u8)
			((key[l >> 3U] & bytebit[m]) == bytebit[m] ? 1 : 0);
	}

	for (i = 0; i < 16; i++) {
		if (decrypt)
			m = (15 - i) << 1;
		else
			m = i << 1;
		n = m + 1;
		kn[m] = kn[n] = 0L;
		for (j = 0; j < 28; j++) {
			l = j + (u32) totrot[i];
			if (l < 28)
				pcr[j] = pc1m[l];
			else
				pcr[j] = pc1m[l - 28];
		}
		for (/* j = 28 */; j < 56; j++) {
			l = j + (u32) totrot[i];
			if (l < 56)
				pcr[j] = pc1m[l];
			else
				pcr[j] = pc1m[l - 28];
		}
		for (j = 0; j < 24; j++) {
			if ((int) pcr[(int) pc2[j]] != 0)
				kn[m] |= bigbyte[j];
			if ((int) pcr[(int) pc2[j + 24]] != 0)
				kn[n] |= bigbyte[j];
		}
	}

	cookey(kn, keyout);
}


static void desfunc(u32 *block, const u32 *keys)
{
	u32 work, right, leftt;
	int cur_round;

	leftt = block[0];
	right = block[1];

	work = ((leftt >> 4)  ^ right) & 0x0f0f0f0fL;
	right ^= work;
	leftt ^= (work << 4);

	work = ((leftt >> 16) ^ right) & 0x0000ffffL;
	right ^= work;
	leftt ^= (work << 16);

	work = ((right >> 2)  ^ leftt) & 0x33333333L;
	leftt ^= work;
	right ^= (work << 2);

	work = ((right >> 8)  ^ leftt) & 0x00ff00ffL;
	leftt ^= work;
	right ^= (work << 8);

	right = ROLc(right, 1);
	work = (leftt ^ right) & 0xaaaaaaaaL;

	leftt ^= work;
	right ^= work;
	leftt = ROLc(leftt, 1);

	for (cur_round = 0; cur_round < 8; cur_round++) {
		work  = RORc(right, 4) ^ *keys++;
		leftt ^= SP7[work        & 0x3fL]
			^ SP5[(work >>  8) & 0x3fL]
			^ SP3[(work >> 16) & 0x3fL]
			^ SP1[(work >> 24) & 0x3fL];
		work  = right ^ *keys++;
		leftt ^= SP8[ work        & 0x3fL]
			^  SP6[(work >>  8) & 0x3fL]
			^  SP4[(work >> 16) & 0x3fL]
			^  SP2[(work >> 24) & 0x3fL];

		work = RORc(leftt, 4) ^ *keys++;
		right ^= SP7[ work        & 0x3fL]
			^  SP5[(work >>  8) & 0x3fL]
			^  SP3[(work >> 16) & 0x3fL]
			^  SP1[(work >> 24) & 0x3fL];
		work  = leftt ^ *keys++;
		right ^= SP8[ work        & 0x3fL]
			^  SP6[(work >>  8) & 0x3fL]
			^  SP4[(work >> 16) & 0x3fL]
			^  SP2[(work >> 24) & 0x3fL];
	}

	right = RORc(right, 1);
	work = (leftt ^ right) & 0xaaaaaaaaL;
	leftt ^= work;
	right ^= work;
	leftt = RORc(leftt, 1);
	work = ((leftt >> 8) ^ right) & 0x00ff00ffL;
	right ^= work;
	leftt ^= (work << 8);
	/* -- */
	work = ((leftt >> 2) ^ right) & 0x33333333L;
	right ^= work;
	leftt ^= (work << 2);
	work = ((right >> 16) ^ leftt) & 0x0000ffffL;
	leftt ^= work;
	right ^= (work << 16);
	work = ((right >> 4) ^ leftt) & 0x0f0f0f0fL;
	leftt ^= work;
	right ^= (work << 4);

	block[0] = right;
	block[1] = leftt;
}


/* wpa_supplicant/hostapd specific wrapper */

int des_encrypt(const u8 *clear, const u8 *key, u8 *cypher)
{
	u8 pkey[8], next, tmp;
	int i;
	u32 ek[32], work[2];

	/* Add parity bits to the key */
	next = 0;
	for (i = 0; i < 7; i++) {
		tmp = key[i];
		pkey[i] = (tmp >> i) | next | 1;
		next = tmp << (7 - i);
	}
	pkey[i] = next | 1;

	deskey(pkey, 0, ek);

	work[0] = WPA_GET_BE32(clear);
	work[1] = WPA_GET_BE32(clear + 4);
	desfunc(work, ek);
	WPA_PUT_BE32(cypher, work[0]);
	WPA_PUT_BE32(cypher + 4, work[1]);

	os_memset(pkey, 0, sizeof(pkey));
	os_memset(ek, 0, sizeof(ek));
	return 0;
}


void des_key_setup(const u8 *key, u32 *ek, u32 *dk)
{
	deskey(key, 0, ek);
	deskey(key, 1, dk);
}


void des_block_encrypt(const u8 *plain, const u32 *ek, u8 *crypt)
{
	u32 work[2];
	work[0] = WPA_GET_BE32(plain);
	work[1] = WPA_GET_BE32(plain + 4);
	desfunc(work, ek);
	WPA_PUT_BE32(crypt, work[0]);
	WPA_PUT_BE32(crypt + 4, work[1]);
}


void des_block_decrypt(const u8 *crypt, const u32 *dk, u8 *plain)
{
	u32 work[2];
	work[0] = WPA_GET_BE32(crypt);
	work[1] = WPA_GET_BE32(crypt + 4);
	desfunc(work, dk);
	WPA_PUT_BE32(plain, work[0]);
	WPA_PUT_BE32(plain + 4, work[1]);
}


void des3_key_setup(const u8 *key, struct des3_key_s *dkey)
{
	deskey(key, 0, dkey->ek[0]);
	deskey(key + 8, 1, dkey->ek[1]);
	deskey(key + 16, 0, dkey->ek[2]);

	deskey(key, 1, dkey->dk[2]);
	deskey(key + 8, 0, dkey->dk[1]);
	deskey(key + 16, 1, dkey->dk[0]);
}


void des3_encrypt(const u8 *plain, const struct des3_key_s *key, u8 *crypt)
{
	u32 work[2];

	work[0] = WPA_GET_BE32(plain);
	work[1] = WPA_GET_BE32(plain + 4);
	desfunc(work, key->ek[0]);
	desfunc(work, key->ek[1]);
	desfunc(work, key->ek[2]);
	WPA_PUT_BE32(crypt, work[0]);
	WPA_PUT_BE32(crypt + 4, work[1]);
}


void des3_decrypt(const u8 *crypt, const struct des3_key_s *key, u8 *plain)
{
	u32 work[2];

	work[0] = WPA_GET_BE32(crypt);
	work[1] = WPA_GET_BE32(crypt + 4);
	desfunc(work, key->dk[0]);
	desfunc(work, key->dk[1]);
	desfunc(work, key->dk[2]);
	WPA_PUT_BE32(plain, work[0]);
	WPA_PUT_BE32(plain + 4, work[1]);
}