[u/mdw/catacomb] / skipjack.c

/* -*-c-*-
 *
 * $Id: skipjack.c,v 1.2 2000/07/15 20:48:45 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.
 */

/*----- Revision history --------------------------------------------------* 
 *
 * $Log: skipjack.c,v $
 * Revision 1.2  2000/07/15 20:48:45  mdw
 * Remove some useless tests in the G function.
 *
 * Revision 1.1  2000/07/15 15:39:33  mdw
 * The NSA's Skipjack block cipher.
 *
 */

/*----- 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 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)
{
  KSZ_ASSERT(skipjack, sz);
  memcpy(k->k, buf, sz);
}

/* --- @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, i) do {							\
  octet _x = U8(x >> 8), _y = U8(x);					\
  _x ^= f[_y ^ k->k[i++]];						\
  _y ^= f[_x ^ k->k[i++]]; if (i >= 10) i = 0;				\
  _x ^= f[_y ^ k->k[i++]];						\
  _y ^= f[_x ^ k->k[i++]]; if (i >= 10) i = 0;				\
  x = U16((_x << 8) | _y);						\
} while (0)

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

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

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

  RULE_A(w, x, y, z, n, i); RULE_A(z, w, x, y, n, i);
  RULE_A(y, z, w, x, n, i); RULE_A(x, y, z, w, n, i);
  RULE_A(w, x, y, z, n, i); RULE_A(z, w, x, y, n, i);
  RULE_A(y, z, w, x, n, i); RULE_A(x, y, z, w, n, i);
  RULE_B(w, x, y, z, n, i); RULE_B(z, w, x, y, n, i);
  RULE_B(y, z, w, x, n, i); RULE_B(x, y, z, w, n, i);
  RULE_B(w, x, y, z, n, i); RULE_B(z, w, x, y, n, i);
  RULE_B(y, z, w, x, n, i); RULE_B(x, y, z, w, n, i);
  RULE_A(w, x, y, z, n, i); RULE_A(z, w, x, y, n, i);
  RULE_A(y, z, w, x, n, i); RULE_A(x, y, z, w, n, i);
  RULE_A(w, x, y, z, n, i); RULE_A(z, w, x, y, n, i);
  RULE_A(y, z, w, x, n, i); RULE_A(x, y, z, w, n, i);
  RULE_B(w, x, y, z, n, i); RULE_B(z, w, x, y, n, i);
  RULE_B(y, z, w, x, n, i); RULE_B(x, y, z, w, n, i);
  RULE_B(w, x, y, z, n, i); RULE_B(z, w, x, y, n, i);
  RULE_B(y, z, w, x, n, i); RULE_B(x, y, z, w, n, i);

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

#define G_INV(x, i) do {						\
  octet _x = U8(x >> 8), _y = U8(x);					\
  _y ^= f[_x ^ k->k[--i]];						\
  _x ^= f[_y ^ k->k[--i]]; if (i == 0) i = 10;				\
  _y ^= f[_x ^ k->k[--i]];						\
  _x ^= f[_y ^ k->k[--i]]; if (i == 0) i = 10;				\
  x = U16((_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 i = 8;
  unsigned n = 33;
  uint16 w = U16(s[0] >> 16), x = U16(s[0]);
  uint16 y = U16(s[1] >> 16), z = U16(s[1]);

  RULE_B_INV(w, x, y, z, n, i); RULE_B_INV(x, y, z, w, n, i);
  RULE_B_INV(y, z, w, x, n, i); RULE_B_INV(z, w, x, y, n, i);
  RULE_B_INV(w, x, y, z, n, i); RULE_B_INV(x, y, z, w, n, i);
  RULE_B_INV(y, z, w, x, n, i); RULE_B_INV(z, w, x, y, n, i);
  RULE_A_INV(w, x, y, z, n, i); RULE_A_INV(x, y, z, w, n, i);
  RULE_A_INV(y, z, w, x, n, i); RULE_A_INV(z, w, x, y, n, i);
  RULE_A_INV(w, x, y, z, n, i); RULE_A_INV(x, y, z, w, n, i);
  RULE_A_INV(y, z, w, x, n, i); RULE_A_INV(z, w, x, y, n, i);
  RULE_B_INV(w, x, y, z, n, i); RULE_B_INV(x, y, z, w, n, i);
  RULE_B_INV(y, z, w, x, n, i); RULE_B_INV(z, w, x, y, n, i);
  RULE_B_INV(w, x, y, z, n, i); RULE_B_INV(x, y, z, w, n, i);
  RULE_B_INV(y, z, w, x, n, i); RULE_B_INV(z, w, x, y, n, i);
  RULE_A_INV(w, x, y, z, n, i); RULE_A_INV(x, y, z, w, n, i);
  RULE_A_INV(y, z, w, x, n, i); RULE_A_INV(z, w, x, y, n, i);
  RULE_A_INV(w, x, y, z, n, i); RULE_A_INV(x, y, z, w, n, i);
  RULE_A_INV(y, z, w, x, n, i); RULE_A_INV(z, w, x, y, n, i);

  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	*
5125b5b7	3	* $Id: skipjack.c,v 1.2 2000/07/15 20:48:45 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	*/
	29
	30	/----- Revision history --------------------------------------------------
	31	*
	32	* $Log: skipjack.c,v $
5125b5b7	33	* Revision 1.2 2000/07/15 20:48:45 mdw
	34	* Remove some useless tests in the G function.
	35	*
6a0a5bdc	36	* Revision 1.1 2000/07/15 15:39:33 mdw
	37	* The NSA's Skipjack block cipher.
	38	*
	39	*/
	40
	41	/----- Header files ------------------------------------------------------/
	42
	43	#include <mLib/bits.h>
	44
	45	#include "blkc.h"
	46	#include "gcipher.h"
	47	#include "skipjack.h"
	48	#include "skipjack-tab.h"
	49
	50	/----- Global variables --------------------------------------------------/
	51
	52	const octet skipjack_keysz[] = { KSZ_SET, 10, 0 };
	53
	54	/----- The Skipjack S-box ------------------------------------------------/
	55
	56	static octet f[256] = SKIPJACK_S;
	57
	58	/----- Main code ---------------------------------------------------------/
	59
	60	/* --- @skipjack_init@ --- *
	61	*
	62	* Arguments: @skipjack_ctx *k@ = pointer to key block
	63	* @const void *buf@ = pointer to key buffer
	64	* @size_t sz@ = size of key material
	65	*
	66	* Returns: ---
	67	*
	68	* Use: Initializes a Skipjack key buffer. The key buffer must be
	69	* exactly 10 bytes long.
	70	*/
	71
	72	void skipjack_init(skipjack_ctx k, const void buf, size_t sz)
	73	{
	74	KSZ_ASSERT(skipjack, sz);
	75	memcpy(k->k, buf, sz);
	76	}
	77
	78	/* --- @skipjack_eblk@, @skipjack_dblk@ --- *
	79	*
	80	* Arguments: @const skipjack_ctx *k@ = pointer to key block
	81	* @const uint32 s[2]@ = pointer to source block
	82	* @uint32 d[2]@ = pointer to skipjacktination block
	83	*
	84	* Returns: ---
	85	*
	86	* Use: Low-level block encryption and decryption.
	87	*/
	88
	89	#define G(x, i) do { \
	90	octet _x = U8(x >> 8), _y = U8(x); \
5125b5b7	91	_x ^= f[_y ^ k->k[i++]]; \
6a0a5bdc	92	_y ^= f[_x ^ k->k[i++]]; if (i >= 10) i = 0; \
5125b5b7	93	_x ^= f[_y ^ k->k[i++]]; \
6a0a5bdc	94	_y ^= f[_x ^ k->k[i++]]; if (i >= 10) i = 0; \
	95	x = U16((_x << 8) \| _y); \
	96	} while (0)
	97
	98	#define RULE_A(w, x, y, z, n, i) do { \
	99	G(w, i); z ^= w ^ n++; \
	100	} while (0)
	101
	102	#define RULE_B(w, x, y, z, n, i) do { \
	103	x ^= w ^ n++; G(w, i); \
	104	} while (0)
	105
	106	void skipjack_eblk(const skipjack_ctx k, const uint32 s, uint32 *d)
	107	{
	108	unsigned i = 0;
	109	unsigned n = 1;
	110	uint16 w = U16(s[0] >> 16), x = U16(s[0]);
	111	uint16 y = U16(s[1] >> 16), z = U16(s[1]);
	112
	113	RULE_A(w, x, y, z, n, i); RULE_A(z, w, x, y, n, i);
	114	RULE_A(y, z, w, x, n, i); RULE_A(x, y, z, w, n, i);
	115	RULE_A(w, x, y, z, n, i); RULE_A(z, w, x, y, n, i);
	116	RULE_A(y, z, w, x, n, i); RULE_A(x, y, z, w, n, i);
	117	RULE_B(w, x, y, z, n, i); RULE_B(z, w, x, y, n, i);
	118	RULE_B(y, z, w, x, n, i); RULE_B(x, y, z, w, n, i);
	119	RULE_B(w, x, y, z, n, i); RULE_B(z, w, x, y, n, i);
	120	RULE_B(y, z, w, x, n, i); RULE_B(x, y, z, w, n, i);
	121	RULE_A(w, x, y, z, n, i); RULE_A(z, w, x, y, n, i);
	122	RULE_A(y, z, w, x, n, i); RULE_A(x, y, z, w, n, i);
	123	RULE_A(w, x, y, z, n, i); RULE_A(z, w, x, y, n, i);
	124	RULE_A(y, z, w, x, n, i); RULE_A(x, y, z, w, n, i);
	125	RULE_B(w, x, y, z, n, i); RULE_B(z, w, x, y, n, i);
	126	RULE_B(y, z, w, x, n, i); RULE_B(x, y, z, w, n, i);
	127	RULE_B(w, x, y, z, n, i); RULE_B(z, w, x, y, n, i);
	128	RULE_B(y, z, w, x, n, i); RULE_B(x, y, z, w, n, i);
	129
	130	d[0] = ((uint32)w << 16) \| (uint32)x;
	131	d[1] = ((uint32)y << 16) \| (uint32)z;
	132	}
	133
	134	#define G_INV(x, i) do { \
	135	octet _x = U8(x >> 8), _y = U8(x); \
5125b5b7	136	_y ^= f[_x ^ k->k[--i]]; \
6a0a5bdc	137	_x ^= f[_y ^ k->k[--i]]; if (i == 0) i = 10; \
5125b5b7	138	_y ^= f[_x ^ k->k[--i]]; \
6a0a5bdc	139	_x ^= f[_y ^ k->k[--i]]; if (i == 0) i = 10; \
	140	x = U16((_x << 8) \| _y); \
	141	} while (0)
	142
	143	#define RULE_A_INV(w, x, y, z, n, i) do { \
	144	w ^= x ^ --n; G_INV(x, i); \
	145	} while (0)
	146
	147	#define RULE_B_INV(w, x, y, z, n, i) do { \
	148	G_INV(x, i); y ^= x ^ --n; \
	149	} while (0)
	150
	151	void skipjack_dblk(const skipjack_ctx k, const uint32 s, uint32 *d)
	152	{
	153	unsigned i = 8;
	154	unsigned n = 33;
	155	uint16 w = U16(s[0] >> 16), x = U16(s[0]);
	156	uint16 y = U16(s[1] >> 16), z = U16(s[1]);
	157
	158	RULE_B_INV(w, x, y, z, n, i); RULE_B_INV(x, y, z, w, n, i);
	159	RULE_B_INV(y, z, w, x, n, i); RULE_B_INV(z, w, x, y, n, i);
	160	RULE_B_INV(w, x, y, z, n, i); RULE_B_INV(x, y, z, w, n, i);
	161	RULE_B_INV(y, z, w, x, n, i); RULE_B_INV(z, w, x, y, n, i);
	162	RULE_A_INV(w, x, y, z, n, i); RULE_A_INV(x, y, z, w, n, i);
	163	RULE_A_INV(y, z, w, x, n, i); RULE_A_INV(z, w, x, y, n, i);
	164	RULE_A_INV(w, x, y, z, n, i); RULE_A_INV(x, y, z, w, n, i);
	165	RULE_A_INV(y, z, w, x, n, i); RULE_A_INV(z, w, x, y, n, i);
	166	RULE_B_INV(w, x, y, z, n, i); RULE_B_INV(x, y, z, w, n, i);
	167	RULE_B_INV(y, z, w, x, n, i); RULE_B_INV(z, w, x, y, n, i);
	168	RULE_B_INV(w, x, y, z, n, i); RULE_B_INV(x, y, z, w, n, i);
	169	RULE_B_INV(y, z, w, x, n, i); RULE_B_INV(z, w, x, y, n, i);
	170	RULE_A_INV(w, x, y, z, n, i); RULE_A_INV(x, y, z, w, n, i);
	171	RULE_A_INV(y, z, w, x, n, i); RULE_A_INV(z, w, x, y, n, i);
	172	RULE_A_INV(w, x, y, z, n, i); RULE_A_INV(x, y, z, w, n, i);
	173	RULE_A_INV(y, z, w, x, n, i); RULE_A_INV(z, w, x, y, n, i);
	174
	175	d[0] = ((uint32)w << 16) \| (uint32)x;
	176	d[1] = ((uint32)y << 16) \| (uint32)z;
	177	}
	178
	179	BLKC_TEST(SKIPJACK, skipjack)
	180
	181	/----- That's all, folks -------------------------------------------------/