[u/mdw/catacomb] / skipjack.c

/* -*-c-*-
 *
 * $Id: skipjack.c,v 1.5 2004/04/08 01:36:15 mdw Exp $
 *
 * The Skipjack block cipher
 *
 * (c) 2000 Straylight/Edgeware
 */

/*----- Licensing notice --------------------------------------------------* 
 *
 * This file is part of Catacomb.
 *
 * Catacomb is free software; you can redistribute it and/or modify
 * it under the terms of the GNU Library General Public License as
 * published by the Free Software Foundation; either version 2 of the
 * License, or (at your option) any later version.
 * 
 * Catacomb 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 Library General Public License for more details.
 * 
 * You should have received a copy of the GNU Library General Public
 * License along with Catacomb; if not, write to the Free
 * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
 * MA 02111-1307, USA.
 */

/*----- Header files ------------------------------------------------------*/

#include <mLib/bits.h>

#include "blkc.h"
#include "gcipher.h"
#include "skipjack.h"
#include "skipjack-tab.h"

/*----- Global variables --------------------------------------------------*/

const octet skipjack_keysz[] = { KSZ_SET, 10, 0 };

/*----- The Skipjack S-box ------------------------------------------------*/

static const octet f[256] = SKIPJACK_S;

/*----- Main code ---------------------------------------------------------*/

/* --- @skipjack_init@ --- *
 *
 * Arguments:   @skipjack_ctx *k@ = pointer to key block
 *              @const void *buf@ = pointer to key buffer
 *              @size_t sz@ = size of key material
 *
 * Returns:     ---
 *
 * Use:         Initializes a Skipjack key buffer.  The key buffer must be
 *		exactly 10 bytes long.
 */

void skipjack_init(skipjack_ctx *k, const void *buf, size_t sz)
{
  const octet *b = buf;
  uint32 crud;
  KSZ_ASSERT(skipjack, sz);
  k->ka = LOAD32(b);
  k->kb = LOAD32(b + 4);
  crud = LOAD16(b + 8);
  k->kc = U32((crud << 16) | (k->ka >> 16));
  k->kd = U32((k->ka << 16) | (k->kb >> 16));
  k->ke = U32((k->kb << 16) | crud);
  crud = 0;
}

/* --- @skipjack_eblk@, @skipjack_dblk@ --- *
 *
 * Arguments:   @const skipjack_ctx *k@ = pointer to key block
 *              @const uint32 s[2]@ = pointer to source block
 *              @uint32 d[2]@ = pointer to skipjacktination block
 *
 * Returns:     ---
 *
 * Use:         Low-level block encryption and decryption.
 */

#define G(x, k) do {							\
  octet _x = U8(x >> 8), _y = U8(x);					\
  _x ^= f[_y ^ U8(k >> 24)];						\
  _y ^= f[_x ^ U8(k >> 16)];						\
  _x ^= f[_y ^ U8(k >>  8)];						\
  _y ^= f[_x ^ U8(k >>  0)];						\
  x = (_x << 8) | _y;							\
} while (0)

#define RULE_A(w, x, y, z, n, k) do {					\
  G(w, k); z ^= w ^ n++;						\
} while (0)

#define RULE_B(w, x, y, z, n, k) do {					\
  x ^= w ^ n++; G(w, k);						\
} while (0)

void skipjack_eblk(const skipjack_ctx *k, const uint32 *s, uint32 *d)
{
  unsigned n = 1;
  uint16 w = U16(s[0] >> 16), x = U16(s[0]);
  uint16 y = U16(s[1] >> 16), z = U16(s[1]);
  uint32 ka = k->ka, kb = k->kb, kc = k->kc, kd = k->kd, ke = k->ke;

  RULE_A(w, x, y, z, n, ka); RULE_A(z, w, x, y, n, kb);
  RULE_A(y, z, w, x, n, kc); RULE_A(x, y, z, w, n, kd);
  RULE_A(w, x, y, z, n, ke); RULE_A(z, w, x, y, n, ka);
  RULE_A(y, z, w, x, n, kb); RULE_A(x, y, z, w, n, kc);
  RULE_B(w, x, y, z, n, kd); RULE_B(z, w, x, y, n, ke);
  RULE_B(y, z, w, x, n, ka); RULE_B(x, y, z, w, n, kb);
  RULE_B(w, x, y, z, n, kc); RULE_B(z, w, x, y, n, kd);
  RULE_B(y, z, w, x, n, ke); RULE_B(x, y, z, w, n, ka);
  RULE_A(w, x, y, z, n, kb); RULE_A(z, w, x, y, n, kc);
  RULE_A(y, z, w, x, n, kd); RULE_A(x, y, z, w, n, ke);
  RULE_A(w, x, y, z, n, ka); RULE_A(z, w, x, y, n, kb);
  RULE_A(y, z, w, x, n, kc); RULE_A(x, y, z, w, n, kd);
  RULE_B(w, x, y, z, n, ke); RULE_B(z, w, x, y, n, ka);
  RULE_B(y, z, w, x, n, kb); RULE_B(x, y, z, w, n, kc);
  RULE_B(w, x, y, z, n, kd); RULE_B(z, w, x, y, n, ke);
  RULE_B(y, z, w, x, n, ka); RULE_B(x, y, z, w, n, kb);

  d[0] = ((uint32)w << 16) | (uint32)x;
  d[1] = ((uint32)y << 16) | (uint32)z;
}

#define G_INV(x, k) do {						\
  octet _x = U8(x >> 8), _y = U8(x);					\
  _y ^= f[_x ^ U8(k >>  0)];						\
  _x ^= f[_y ^ U8(k >>  8)];						\
  _y ^= f[_x ^ U8(k >> 16)];						\
  _x ^= f[_y ^ U8(k >> 24)];						\
  x = (_x << 8) | _y;							\
} while (0)

#define RULE_A_INV(w, x, y, z, n, i) do {				\
  w ^= x ^ --n; G_INV(x, i);						\
} while (0)

#define RULE_B_INV(w, x, y, z, n, i) do {				\
  G_INV(x, i); y ^= x ^ --n;						\
} while (0)

void skipjack_dblk(const skipjack_ctx *k, const uint32 *s, uint32 *d)
{
  unsigned n = 33;
  uint16 w = U16(s[0] >> 16), x = U16(s[0]);
  uint16 y = U16(s[1] >> 16), z = U16(s[1]);
  uint32 ka = k->ka, kb = k->kb, kc = k->kc, kd = k->kd, ke = k->ke;

  RULE_B_INV(w, x, y, z, n, kb); RULE_B_INV(x, y, z, w, n, ka);
  RULE_B_INV(y, z, w, x, n, ke); RULE_B_INV(z, w, x, y, n, kd);
  RULE_B_INV(w, x, y, z, n, kc); RULE_B_INV(x, y, z, w, n, kb);
  RULE_B_INV(y, z, w, x, n, ka); RULE_B_INV(z, w, x, y, n, ke);
  RULE_A_INV(w, x, y, z, n, kd); RULE_A_INV(x, y, z, w, n, kc);
  RULE_A_INV(y, z, w, x, n, kb); RULE_A_INV(z, w, x, y, n, ka);
  RULE_A_INV(w, x, y, z, n, ke); RULE_A_INV(x, y, z, w, n, kd);
  RULE_A_INV(y, z, w, x, n, kc); RULE_A_INV(z, w, x, y, n, kb);
  RULE_B_INV(w, x, y, z, n, ka); RULE_B_INV(x, y, z, w, n, ke);
  RULE_B_INV(y, z, w, x, n, kd); RULE_B_INV(z, w, x, y, n, kc);
  RULE_B_INV(w, x, y, z, n, kb); RULE_B_INV(x, y, z, w, n, ka);
  RULE_B_INV(y, z, w, x, n, ke); RULE_B_INV(z, w, x, y, n, kd);
  RULE_A_INV(w, x, y, z, n, kc); RULE_A_INV(x, y, z, w, n, kb);
  RULE_A_INV(y, z, w, x, n, ka); RULE_A_INV(z, w, x, y, n, ke);
  RULE_A_INV(w, x, y, z, n, kd); RULE_A_INV(x, y, z, w, n, kc);
  RULE_A_INV(y, z, w, x, n, kb); RULE_A_INV(z, w, x, y, n, ka);

  d[0] = ((uint32)w << 16) | (uint32)x;
  d[1] = ((uint32)y << 16) | (uint32)z;
}

BLKC_TEST(SKIPJACK, skipjack)

/*----- That's all, folks -------------------------------------------------*/
Commit	Line	Data
6a0a5bdc	1	/* --c--
6a0a5bdc	2	*
b817bfc6	3	* $Id: skipjack.c,v 1.5 2004/04/08 01:36:15 mdw Exp $
6a0a5bdc	4	*
	5	* The Skipjack block cipher
	6	*
	7	* (c) 2000 Straylight/Edgeware
	8	*/
	9
	10	/----- Licensing notice --------------------------------------------------
	11	*
	12	* This file is part of Catacomb.
	13	*
	14	* Catacomb is free software; you can redistribute it and/or modify
	15	* it under the terms of the GNU Library General Public License as
	16	* published by the Free Software Foundation; either version 2 of the
	17	* License, or (at your option) any later version.
	18	*
	19	* Catacomb is distributed in the hope that it will be useful,
	20	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	21	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	22	* GNU Library General Public License for more details.
	23	*
	24	* You should have received a copy of the GNU Library General Public
	25	* License along with Catacomb; if not, write to the Free
	26	* Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
	27	* MA 02111-1307, USA.
	28	*/
6a0a5bdc	29
	30	/----- Header files ------------------------------------------------------/
	31
	32	#include <mLib/bits.h>
	33
	34	#include "blkc.h"
	35	#include "gcipher.h"
	36	#include "skipjack.h"
	37	#include "skipjack-tab.h"
	38
	39	/----- Global variables --------------------------------------------------/
	40
	41	const octet skipjack_keysz[] = { KSZ_SET, 10, 0 };
	42
	43	/----- The Skipjack S-box ------------------------------------------------/
	44
4e66da02	45	static const octet f[256] = SKIPJACK_S;
6a0a5bdc	46
	47	/----- Main code ---------------------------------------------------------/
	48
	49	/* --- @skipjack_init@ --- *
	50	*
	51	* Arguments: @skipjack_ctx *k@ = pointer to key block
	52	* @const void *buf@ = pointer to key buffer
	53	* @size_t sz@ = size of key material
	54	*
	55	* Returns: ---
	56	*
	57	* Use: Initializes a Skipjack key buffer. The key buffer must be
	58	* exactly 10 bytes long.
	59	*/
	60
	61	void skipjack_init(skipjack_ctx k, const void buf, size_t sz)
	62	{
fe371977	63	const octet *b = buf;
fe371977	64	uint32 crud;
6a0a5bdc	65	KSZ_ASSERT(skipjack, sz);
fe371977	66	k->ka = LOAD32(b);
	67	k->kb = LOAD32(b + 4);
	68	crud = LOAD16(b + 8);
	69	k->kc = U32((crud << 16) \| (k->ka >> 16));
	70	k->kd = U32((k->ka << 16) \| (k->kb >> 16));
	71	k->ke = U32((k->kb << 16) \| crud);
	72	crud = 0;
6a0a5bdc	73	}
	74
	75	/* --- @skipjack_eblk@, @skipjack_dblk@ --- *
	76	*
	77	* Arguments: @const skipjack_ctx *k@ = pointer to key block
	78	* @const uint32 s[2]@ = pointer to source block
	79	* @uint32 d[2]@ = pointer to skipjacktination block
	80	*
	81	* Returns: ---
	82	*
	83	* Use: Low-level block encryption and decryption.
	84	*/
	85
fe371977	86	#define G(x, k) do { \
6a0a5bdc	87	octet _x = U8(x >> 8), _y = U8(x); \
fe371977	88	_x ^= f[_y ^ U8(k >> 24)]; \
	89	_y ^= f[_x ^ U8(k >> 16)]; \
	90	_x ^= f[_y ^ U8(k >> 8)]; \
	91	_y ^= f[_x ^ U8(k >> 0)]; \
	92	x = (_x << 8) \| _y; \
6a0a5bdc	93	} while (0)
6a0a5bdc	94
fe371977	95	#define RULE_A(w, x, y, z, n, k) do { \
fe371977	96	G(w, k); z ^= w ^ n++; \
6a0a5bdc	97	} while (0)
6a0a5bdc	98
fe371977	99	#define RULE_B(w, x, y, z, n, k) do { \
fe371977	100	x ^= w ^ n++; G(w, k); \
6a0a5bdc	101	} while (0)
	102
	103	void skipjack_eblk(const skipjack_ctx k, const uint32 s, uint32 *d)
	104	{
6a0a5bdc	105	unsigned n = 1;
	106	uint16 w = U16(s[0] >> 16), x = U16(s[0]);
	107	uint16 y = U16(s[1] >> 16), z = U16(s[1]);
fe371977	108	uint32 ka = k->ka, kb = k->kb, kc = k->kc, kd = k->kd, ke = k->ke;
	109
	110	RULE_A(w, x, y, z, n, ka); RULE_A(z, w, x, y, n, kb);
	111	RULE_A(y, z, w, x, n, kc); RULE_A(x, y, z, w, n, kd);
	112	RULE_A(w, x, y, z, n, ke); RULE_A(z, w, x, y, n, ka);
	113	RULE_A(y, z, w, x, n, kb); RULE_A(x, y, z, w, n, kc);
	114	RULE_B(w, x, y, z, n, kd); RULE_B(z, w, x, y, n, ke);
	115	RULE_B(y, z, w, x, n, ka); RULE_B(x, y, z, w, n, kb);
	116	RULE_B(w, x, y, z, n, kc); RULE_B(z, w, x, y, n, kd);
	117	RULE_B(y, z, w, x, n, ke); RULE_B(x, y, z, w, n, ka);
	118	RULE_A(w, x, y, z, n, kb); RULE_A(z, w, x, y, n, kc);
	119	RULE_A(y, z, w, x, n, kd); RULE_A(x, y, z, w, n, ke);
	120	RULE_A(w, x, y, z, n, ka); RULE_A(z, w, x, y, n, kb);
	121	RULE_A(y, z, w, x, n, kc); RULE_A(x, y, z, w, n, kd);
	122	RULE_B(w, x, y, z, n, ke); RULE_B(z, w, x, y, n, ka);
	123	RULE_B(y, z, w, x, n, kb); RULE_B(x, y, z, w, n, kc);
	124	RULE_B(w, x, y, z, n, kd); RULE_B(z, w, x, y, n, ke);
	125	RULE_B(y, z, w, x, n, ka); RULE_B(x, y, z, w, n, kb);
6a0a5bdc	126
	127	d[0] = ((uint32)w << 16) \| (uint32)x;
	128	d[1] = ((uint32)y << 16) \| (uint32)z;
	129	}
	130
fe371977	131	#define G_INV(x, k) do { \
6a0a5bdc	132	octet _x = U8(x >> 8), _y = U8(x); \
fe371977	133	_y ^= f[_x ^ U8(k >> 0)]; \
	134	_x ^= f[_y ^ U8(k >> 8)]; \
	135	_y ^= f[_x ^ U8(k >> 16)]; \
	136	_x ^= f[_y ^ U8(k >> 24)]; \
	137	x = (_x << 8) \| _y; \
6a0a5bdc	138	} while (0)
	139
	140	#define RULE_A_INV(w, x, y, z, n, i) do { \
	141	w ^= x ^ --n; G_INV(x, i); \
	142	} while (0)
	143
	144	#define RULE_B_INV(w, x, y, z, n, i) do { \
	145	G_INV(x, i); y ^= x ^ --n; \
	146	} while (0)
	147
	148	void skipjack_dblk(const skipjack_ctx k, const uint32 s, uint32 *d)
	149	{
6a0a5bdc	150	unsigned n = 33;
	151	uint16 w = U16(s[0] >> 16), x = U16(s[0]);
	152	uint16 y = U16(s[1] >> 16), z = U16(s[1]);
fe371977	153	uint32 ka = k->ka, kb = k->kb, kc = k->kc, kd = k->kd, ke = k->ke;
	154
	155	RULE_B_INV(w, x, y, z, n, kb); RULE_B_INV(x, y, z, w, n, ka);
	156	RULE_B_INV(y, z, w, x, n, ke); RULE_B_INV(z, w, x, y, n, kd);
	157	RULE_B_INV(w, x, y, z, n, kc); RULE_B_INV(x, y, z, w, n, kb);
	158	RULE_B_INV(y, z, w, x, n, ka); RULE_B_INV(z, w, x, y, n, ke);
	159	RULE_A_INV(w, x, y, z, n, kd); RULE_A_INV(x, y, z, w, n, kc);
	160	RULE_A_INV(y, z, w, x, n, kb); RULE_A_INV(z, w, x, y, n, ka);
	161	RULE_A_INV(w, x, y, z, n, ke); RULE_A_INV(x, y, z, w, n, kd);
	162	RULE_A_INV(y, z, w, x, n, kc); RULE_A_INV(z, w, x, y, n, kb);
	163	RULE_B_INV(w, x, y, z, n, ka); RULE_B_INV(x, y, z, w, n, ke);
	164	RULE_B_INV(y, z, w, x, n, kd); RULE_B_INV(z, w, x, y, n, kc);
	165	RULE_B_INV(w, x, y, z, n, kb); RULE_B_INV(x, y, z, w, n, ka);
	166	RULE_B_INV(y, z, w, x, n, ke); RULE_B_INV(z, w, x, y, n, kd);
	167	RULE_A_INV(w, x, y, z, n, kc); RULE_A_INV(x, y, z, w, n, kb);
	168	RULE_A_INV(y, z, w, x, n, ka); RULE_A_INV(z, w, x, y, n, ke);
	169	RULE_A_INV(w, x, y, z, n, kd); RULE_A_INV(x, y, z, w, n, kc);
	170	RULE_A_INV(y, z, w, x, n, kb); RULE_A_INV(z, w, x, y, n, ka);
6a0a5bdc	171
	172	d[0] = ((uint32)w << 16) \| (uint32)x;
	173	d[1] = ((uint32)y << 16) \| (uint32)z;
	174	}
	175
	176	BLKC_TEST(SKIPJACK, skipjack)
	177
	178	/----- That's all, folks -------------------------------------------------/