[u/mdw/catacomb] / cfb.h

/* -*-c-*-
 *
 * $Id: cfb.h,v 1.3 2000/06/17 10:50:55 mdw Exp $
 *
 * Ciphertext feedback for block ciphers
 *
 * (c) 1999 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: cfb.h,v $
 * Revision 1.3  2000/06/17 10:50:55  mdw
 * Change buffer offset to be unsigned.
 *
 * Revision 1.2  1999/12/10 23:16:39  mdw
 * Split mode macros into interface and implementation.
 *
 * Revision 1.1  1999/09/03 08:41:11  mdw
 * Initial import.
 *
 */

#ifndef CATACOMB_CFB_H
#define CATACOMB_CFB_H

#ifdef __cplusplus
  extern "C" {
#endif

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

#include <stddef.h>

#include <mLib/bits.h>

#ifndef CATACOMB_GCIPHER_H
#  include "gcipher.h"
#endif

/*----- Data structures ---------------------------------------------------*/

/* --- @CFB_DECL@ --- *
 *
 * Arguments:	@PRE@, @pre@ = prefixes for the underlying block cipher
 *
 * Use:		Creates declarations for CFB mode.
 */

#define CFB_DECL(PRE, pre)						\
									\
/* --- Ciphertext feedback context --- */				\
									\
typedef struct pre##_cfbctx {						\
  pre##_ctx ctx;			/* Underlying cipher context */	\
  unsigned off;				/* Offset into @iv@ buffer */	\
  octet iv[PRE##_BLKSZ];		/* Previous ciphertext or IV */	\
} pre##_cfbctx;								\
									\
/* --- @pre_cfbgetiv@ --- *						\
 *									\
 * Arguments:	@const pre_cfbctx *ctx@ = pointer to CFB context block	\
 *		@void *iv#@ = pointer to output data block		\
 *									\
 * Returns:	---							\
 *									\
 * Use:		Reads the currently set IV.  Reading and setting an IV	\
 *		is not transparent to the cipher.  It will add a `step'	\
 *		which must be matched by a similar operation during	\
 *		decryption.						\
 */									\
									\
extern void pre##_cfbgetiv(const pre##_cfbctx */*ctx*/,			\
			   void */*iv*/);				\
									\
/* --- @pre_cfbsetiv@ --- *						\
 *									\
 * Arguments:	@pre_cfbctx *ctx@ = pointer to CFB context block	\
 *		@cnost void *iv@ = pointer to IV to set			\
 *									\
 * Returns:	---							\
 *									\
 * Use:		Sets the IV to use for subsequent encryption.		\
 */									\
									\
extern void pre##_cfbsetiv(pre##_cfbctx */*ctx*/,			\
			   const void */*iv*/);				\
									\
/* --- @pre_cfbbdry@ --- *						\
 *									\
 * Arguments:	@pre_cfbctx *ctx@ = pointer to CFB context block	\
 *									\
 * Returns:	---							\
 *									\
 * Use:		Inserts a boundary during encryption.  Successful	\
 *		decryption must place a similar boundary.		\
 */									\
									\
extern void pre##_cfbbdry(pre##_cfbctx */*ctx*/);			\
									\
/* --- @pre_cfbsetkey@ --- *						\
 *									\
 * Arguments:	@pre_cfbctx *ctx@ = pointer to CFB context block	\
 *		@const pre_ctx *k@ = pointer to cipher context		\
 *									\
 * Returns:	---							\
 *									\
 * Use:		Sets the CFB context to use a different cipher key.	\
 */									\
									\
extern void pre##_cfbsetkey(pre##_cfbctx */*ctx*/,			\
			    const pre##_ctx */*k*/);			\
									\
/* --- @pre_cfbinit@ --- *						\
 *									\
 * Arguments:	@pre_cfbctx *ctx@ = pointer to cipher context		\
 *		@const void *key@ = pointer to the key buffer		\
 *		@size_t sz@ = size of the key				\
 *		@const void *iv@ = pointer to initialization vector	\
 *									\
 * Returns:	---							\
 *									\
 * Use:		Initializes a CFB context ready for use.  You should	\
 *		ensure that the IV chosen is unique: reusing an IV will	\
 *		compromise the security of at least the first block	\
 *		encrypted.  This is equivalent to calls to @pre_init@,	\
 *		@pre_cfbsetkey@ and @pre_cfbsetiv@.			\
 */									\
									\
extern void pre##_cfbinit(pre##_cfbctx */*ctx*/,			\
			  const void */*key*/, size_t /*sz*/,		\
			  const void */*iv*/);				\
									\
/* --- @pre_cfbencrypt@ --- *						\
 *									\
 * Arguments:	@pre_cfbctx *ctx@ = pointer to CFB context block	\
 *		@const void *src@ = pointer to source data		\
 *		@void *dest@ = pointer to destination data		\
 *		@size_t sz@ = size of block to be encrypted		\
 *									\
 * Returns:	---							\
 *									\
 * Use:		Encrypts a block with a block cipher in CFB mode.  The	\
 *		input block may be arbitrary in size.  CFB mode is not	\
 *		sensitive to block boundaries.				\
 */									\
									\
extern void pre##_cfbencrypt(pre##_cfbctx */*ctx*/,			\
			     const void */*src*/, void */*dest*/,	\
			     size_t /*sz*/);				\
									\
/* --- @pre_cfbencrypt@ --- *						\
 *									\
 * Arguments:	@pre_cfbctx *ctx@ = pointer to CFB context block	\
 *		@const void *src@ = pointer to source data		\
 *		@void *dest@ = pointer to destination data		\
 *		@size_t sz@ = size of block to be encrypted		\
 *									\
 * Returns:	---							\
 *									\
 * Use:		Decrypts a block with a block cipher in CFB mode.  The	\
 *		input block may be arbitrary in size.  CFB mode is not	\
 *		sensitive to block boundaries.				\
 */									\
									\
extern void pre##_cfbdecrypt(pre##_cfbctx */*ctx*/,			\
			     const void */*src*/, void */*dest*/,	\
			     size_t /*sz*/);				\
									\
/* --- Generic cipher interface --- */					\
									\
extern const gccipher pre##_cfb;

/*----- That's all, folks -------------------------------------------------*/

#ifdef __cplusplus
  }
#endif

#endif
Commit	Line	Data
d03ab969	1	/* --c--
d03ab969	2	*
e97df21b	3	* $Id: cfb.h,v 1.3 2000/06/17 10:50:55 mdw Exp $
d03ab969	4	*
	5	* Ciphertext feedback for block ciphers
	6	*
	7	* (c) 1999 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: cfb.h,v $
e97df21b	33	* Revision 1.3 2000/06/17 10:50:55 mdw
	34	* Change buffer offset to be unsigned.
	35	*
79ba130c	36	* Revision 1.2 1999/12/10 23:16:39 mdw
	37	* Split mode macros into interface and implementation.
	38	*
d03ab969	39	* Revision 1.1 1999/09/03 08:41:11 mdw
	40	* Initial import.
	41	*
	42	*/
	43
79ba130c	44	#ifndef CATACOMB_CFB_H
79ba130c	45	#define CATACOMB_CFB_H
d03ab969	46
	47	#ifdef __cplusplus
	48	extern "C" {
	49	#endif
	50
	51	/----- Header files ------------------------------------------------------/
	52
79ba130c	53	#include <stddef.h>
d03ab969	54
	55	#include <mLib/bits.h>
	56
79ba130c	57	#ifndef CATACOMB_GCIPHER_H
79ba130c	58	# include "gcipher.h"
d03ab969	59	#endif
	60
	61	/----- Data structures ---------------------------------------------------/
	62
	63	/* --- @CFB_DECL@ --- *
	64	*
	65	* Arguments: @PRE@, @pre@ = prefixes for the underlying block cipher
	66	*
	67	* Use: Creates declarations for CFB mode.
	68	*/
	69
	70	#define CFB_DECL(PRE, pre) \
	71	\
79ba130c	72	/* --- Ciphertext feedback context --- */ \
d03ab969	73	\
79ba130c	74	typedef struct pre##_cfbctx { \
79ba130c	75	pre##_ctx ctx; /* Underlying cipher context */ \
e97df21b	76	unsigned off; /* Offset into @iv@ buffer */ \
79ba130c	77	octet iv[PRE##_BLKSZ]; /* Previous ciphertext or IV */ \
79ba130c	78	} pre##_cfbctx; \
d03ab969	79	\
	80	/* --- @pre_cfbgetiv@ --- * \
	81	* \
	82	* Arguments: @const pre_cfbctx *ctx@ = pointer to CFB context block \
	83	* @void *iv#@ = pointer to output data block \
	84	* \
	85	* Returns: --- \
	86	* \
	87	* Use: Reads the currently set IV. Reading and setting an IV \
	88	* is not transparent to the cipher. It will add a `step' \
	89	* which must be matched by a similar operation during \
	90	* decryption. \
	91	*/ \
	92	\
79ba130c	93	extern void pre##_cfbgetiv(const pre##_cfbctx /ctx*/, \
79ba130c	94	void /iv*/); \
d03ab969	95	\
	96	/* --- @pre_cfbsetiv@ --- * \
	97	* \
	98	* Arguments: @pre_cfbctx *ctx@ = pointer to CFB context block \
	99	* @cnost void *iv@ = pointer to IV to set \
	100	* \
	101	* Returns: --- \
	102	* \
	103	* Use: Sets the IV to use for subsequent encryption. \
	104	*/ \
	105	\
79ba130c	106	extern void pre##_cfbsetiv(pre##_cfbctx /ctx*/, \
79ba130c	107	const void /iv*/); \
d03ab969	108	\
	109	/* --- @pre_cfbbdry@ --- * \
	110	* \
	111	* Arguments: @pre_cfbctx *ctx@ = pointer to CFB context block \
	112	* \
	113	* Returns: --- \
	114	* \
	115	* Use: Inserts a boundary during encryption. Successful \
	116	* decryption must place a similar boundary. \
	117	*/ \
	118	\
79ba130c	119	extern void pre##_cfbbdry(pre##_cfbctx /ctx*/); \
d03ab969	120	\
	121	/* --- @pre_cfbsetkey@ --- * \
	122	* \
	123	* Arguments: @pre_cfbctx *ctx@ = pointer to CFB context block \
	124	* @const pre_ctx *k@ = pointer to cipher context \
	125	* \
	126	* Returns: --- \
	127	* \
	128	* Use: Sets the CFB context to use a different cipher key. \
	129	*/ \
	130	\
79ba130c	131	extern void pre##_cfbsetkey(pre##_cfbctx /ctx*/, \
79ba130c	132	const pre##_ctx /k*/); \
d03ab969	133	\
	134	/* --- @pre_cfbinit@ --- * \
	135	* \
	136	* Arguments: @pre_cfbctx *ctx@ = pointer to cipher context \
	137	* @const void *key@ = pointer to the key buffer \
	138	* @size_t sz@ = size of the key \
	139	* @const void *iv@ = pointer to initialization vector \
	140	* \
	141	* Returns: --- \
	142	* \
	143	* Use: Initializes a CFB context ready for use. You should \
	144	* ensure that the IV chosen is unique: reusing an IV will \
	145	* compromise the security of at least the first block \
	146	* encrypted. This is equivalent to calls to @pre_init@, \
	147	* @pre_cfbsetkey@ and @pre_cfbsetiv@. \
	148	*/ \
	149	\
79ba130c	150	extern void pre##_cfbinit(pre##_cfbctx /ctx*/, \
	151	const void /key/, size_t /sz*/, \
	152	const void /iv*/); \
d03ab969	153	\
	154	/* --- @pre_cfbencrypt@ --- * \
	155	* \
	156	* Arguments: @pre_cfbctx *ctx@ = pointer to CFB context block \
	157	* @const void *src@ = pointer to source data \
	158	* @void *dest@ = pointer to destination data \
	159	* @size_t sz@ = size of block to be encrypted \
	160	* \
	161	* Returns: --- \
	162	* \
	163	* Use: Encrypts a block with a block cipher in CFB mode. The \
	164	* input block may be arbitrary in size. CFB mode is not \
	165	* sensitive to block boundaries. \
	166	*/ \
	167	\
79ba130c	168	extern void pre##_cfbencrypt(pre##_cfbctx /ctx*/, \
	169	const void /src/, void /dest/, \
	170	size_t /sz/); \
d03ab969	171	\
79ba130c	172	/* --- @pre_cfbencrypt@ --- * \
d03ab969	173	* \
	174	* Arguments: @pre_cfbctx *ctx@ = pointer to CFB context block \
	175	* @const void *src@ = pointer to source data \
	176	* @void *dest@ = pointer to destination data \
	177	* @size_t sz@ = size of block to be encrypted \
	178	* \
	179	* Returns: --- \
	180	* \
79ba130c	181	* Use: Decrypts a block with a block cipher in CFB mode. The \
	182	* input block may be arbitrary in size. CFB mode is not \
	183	* sensitive to block boundaries. \
d03ab969	184	*/ \
d03ab969	185	\
79ba130c	186	extern void pre##_cfbdecrypt(pre##_cfbctx /ctx*/, \
	187	const void /src/, void /dest/, \
	188	size_t /sz/); \
d03ab969	189	\
79ba130c	190	/* --- Generic cipher interface --- */ \
d03ab969	191	\
79ba130c	192	extern const gccipher pre##_cfb;
d03ab969	193
	194	/----- That's all, folks -------------------------------------------------/
	195
	196	#ifdef __cplusplus
	197	}
	198	#endif
	199
	200	#endif