[u/mdw/catacomb] / ofb.h

/* -*-c-*-
 *
 * $Id: ofb.h,v 1.3 2000/06/17 11:48:24 mdw Exp $
 *
 * Output 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: ofb.h,v $
 * Revision 1.3  2000/06/17 11:48:24  mdw
 * Change buffer offset to be unsigned.
 *
 * Revision 1.2  1999/12/10 23:16:40  mdw
 * Split mode macros into interface and implementation.
 *
 * Revision 1.1  1999/09/03 08:41:12  mdw
 * Initial import.
 *
 */

#ifndef CATACOMB_OFB_H
#define CATACOMB_OFB_H

#ifdef __cplusplus
  extern "C" {
#endif

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

#include <stddef.h>

#include <mLib/bits.h>

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

#ifndef CATACOMB_GRAND_H
#  include "grand.h"
#endif

/*----- Macros ------------------------------------------------------------*/

/* --- @OFB_DECL@ --- *
 *
 * Arguments:	@PRE@, @pre@ = prefixes for block cipher definitions
 *
 * Use:		Makes declarations for output feedback mode.
 */

#define OFB_DECL(PRE, pre)						\
									\
/* --- Output feedback context --- */					\
									\
typedef struct pre##_ofbctx {						\
  pre##_ctx ctx;			/* Underlying cipher context */	\
  unsigned off;				/* Current offset in buffer */	\
  octet iv[PRE##_BLKSZ];		/* Output buffer and IV */	\
} pre##_ofbctx;								\
									\
/* --- @pre_ofbgetiv@ --- *						\
 *									\
 * Arguments:	@const pre_ofbctx *ctx@ = pointer to OFB 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##_ofbgetiv(const pre##_ofbctx */*ctx*/,			\
			   void */*iv*/);				\
									\
/* --- @pre_ofbsetiv@ --- *						\
 *									\
 * Arguments:	@pre_ofbctx *ctx@ = pointer to OFB context block	\
 *		@cnost void *iv@ = pointer to IV to set			\
 *									\
 * Returns:	---							\
 *									\
 * Use:		Sets the IV to use for subsequent encryption.		\
 */									\
									\
extern void pre##_ofbsetiv(pre##_ofbctx */*ctx*/,			\
			   const void */*iv*/);				\
									\
/* --- @pre_ofbbdry@ --- *						\
 *									\
 * Arguments:	@pre_ofbctx *ctx@ = pointer to OFB context block	\
 *									\
 * Returns:	---							\
 *									\
 * Use:		Inserts a boundary during encryption.  Successful	\
 *		decryption must place a similar boundary.		\
 */									\
									\
extern void pre##_ofbbdry(pre##_ofbctx */*ctx*/);			\
									\
/* --- @pre_ofbsetkey@ --- *						\
 *									\
 * Arguments:	@pre_ofbctx *ctx@ = pointer to OFB context block	\
 *		@const pre_ctx *k@ = pointer to cipher context		\
 *									\
 * Returns:	---							\
 *									\
 * Use:		Sets the OFB context to use a different cipher key.	\
 */									\
									\
extern void pre##_ofbsetkey(pre##_ofbctx */*ctx*/,			\
			    const pre##_ctx */*k*/);			\
									\
/* --- @pre_ofbinit@ --- *						\
 *									\
 * Arguments:	@pre_ofbctx *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 OFB context ready for use.  You should	\
 *		ensure that the IV chosen is unique: reusing an IV will	\
 *		compromise the security of the entire plaintext.  This	\
 *		is equivalent to calls to @pre_init@, @pre_ofbsetkey@	\
 *		and @pre_ofbsetiv@.					\
 */									\
									\
extern void pre##_ofbinit(pre##_ofbctx */*ctx*/,			\
			  const void */*key*/, size_t /*sz*/,		\
			  const void */*iv*/);				\
									\
/* --- @pre_ofbencrypt@ --- *						\
 *									\
 * Arguments:	@pre_ofbctx *ctx@ = pointer to OFB 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 or decrypts a block with a block cipher in OFB	\
 *		mode: encryption and decryption are the same in OFB.	\
 *		The destination may be null to just churn the feedback	\
 *		round for a bit.  The source may be null to use the	\
 *		cipher as a random data generator.			\
 */									\
									\
extern void pre##_ofbencrypt(pre##_ofbctx */*ctx*/,			\
			     const void */*src*/, void */*dest*/,	\
			     size_t /*sz*/);				\
									\
/* --- @pre_ofbrand@ --- *						\
 *									\
 * Arguments:	@const void *k@ = pointer to key material		\
 *		@size_t sz@ = size of key material			\
 *									\
 * Returns:	Pointer to generic random number generator interface.	\
 *									\
 * Use:		Creates a random number interface wrapper around an	\
 *		OFB-mode block cipher.					\
 */									\
									\
extern grand *pre##_ofbrand(const void */*k*/, size_t /*sz*/);		\
									\
/* --- Generic cipher interface --- */					\
									\
extern const gccipher pre##_ofb;

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

#ifdef __cplusplus
  }
#endif

#endif
Commit	Line	Data
d03ab969	1	/* --c--
d03ab969	2	*
75b1b624	3	* $Id: ofb.h,v 1.3 2000/06/17 11:48:24 mdw Exp $
d03ab969	4	*
	5	* Output 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: ofb.h,v $
75b1b624	33	* Revision 1.3 2000/06/17 11:48:24 mdw
	34	* Change buffer offset to be unsigned.
	35	*
79ba130c	36	* Revision 1.2 1999/12/10 23:16:40 mdw
	37	* Split mode macros into interface and implementation.
	38	*
d03ab969	39	* Revision 1.1 1999/09/03 08:41:12 mdw
	40	* Initial import.
	41	*
	42	*/
	43
79ba130c	44	#ifndef CATACOMB_OFB_H
79ba130c	45	#define CATACOMB_OFB_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
d03ab969	60
79ba130c	61	#ifndef CATACOMB_GRAND_H
79ba130c	62	# include "grand.h"
d03ab969	63	#endif
	64
	65	/----- Macros ------------------------------------------------------------/
	66
	67	/* --- @OFB_DECL@ --- *
	68	*
	69	* Arguments: @PRE@, @pre@ = prefixes for block cipher definitions
	70	*
	71	* Use: Makes declarations for output feedback mode.
	72	*/
	73
	74	#define OFB_DECL(PRE, pre) \
	75	\
79ba130c	76	/* --- Output feedback context --- */ \
d03ab969	77	\
79ba130c	78	typedef struct pre##_ofbctx { \
79ba130c	79	pre##_ctx ctx; /* Underlying cipher context */ \
75b1b624	80	unsigned off; /* Current offset in buffer */ \
79ba130c	81	octet iv[PRE##_BLKSZ]; /* Output buffer and IV */ \
79ba130c	82	} pre##_ofbctx; \
d03ab969	83	\
	84	/* --- @pre_ofbgetiv@ --- * \
	85	* \
	86	* Arguments: @const pre_ofbctx *ctx@ = pointer to OFB context block \
	87	* @void *iv#@ = pointer to output data block \
	88	* \
	89	* Returns: --- \
	90	* \
	91	* Use: Reads the currently set IV. Reading and setting an IV \
	92	* is not transparent to the cipher. It will add a `step' \
	93	* which must be matched by a similar operation during \
	94	* decryption. \
	95	*/ \
	96	\
79ba130c	97	extern void pre##_ofbgetiv(const pre##_ofbctx /ctx*/, \
79ba130c	98	void /iv*/); \
d03ab969	99	\
	100	/* --- @pre_ofbsetiv@ --- * \
	101	* \
	102	* Arguments: @pre_ofbctx *ctx@ = pointer to OFB context block \
	103	* @cnost void *iv@ = pointer to IV to set \
	104	* \
	105	* Returns: --- \
	106	* \
	107	* Use: Sets the IV to use for subsequent encryption. \
	108	*/ \
	109	\
79ba130c	110	extern void pre##_ofbsetiv(pre##_ofbctx /ctx*/, \
79ba130c	111	const void /iv*/); \
d03ab969	112	\
	113	/* --- @pre_ofbbdry@ --- * \
	114	* \
	115	* Arguments: @pre_ofbctx *ctx@ = pointer to OFB context block \
	116	* \
	117	* Returns: --- \
	118	* \
	119	* Use: Inserts a boundary during encryption. Successful \
	120	* decryption must place a similar boundary. \
	121	*/ \
	122	\
79ba130c	123	extern void pre##_ofbbdry(pre##_ofbctx /ctx*/); \
d03ab969	124	\
	125	/* --- @pre_ofbsetkey@ --- * \
	126	* \
	127	* Arguments: @pre_ofbctx *ctx@ = pointer to OFB context block \
	128	* @const pre_ctx *k@ = pointer to cipher context \
	129	* \
	130	* Returns: --- \
	131	* \
	132	* Use: Sets the OFB context to use a different cipher key. \
	133	*/ \
	134	\
79ba130c	135	extern void pre##_ofbsetkey(pre##_ofbctx /ctx*/, \
79ba130c	136	const pre##_ctx /k*/); \
d03ab969	137	\
	138	/* --- @pre_ofbinit@ --- * \
	139	* \
	140	* Arguments: @pre_ofbctx *ctx@ = pointer to cipher context \
	141	* @const void *key@ = pointer to the key buffer \
	142	* @size_t sz@ = size of the key \
	143	* @const void *iv@ = pointer to initialization vector \
	144	* \
	145	* Returns: --- \
	146	* \
	147	* Use: Initializes a OFB context ready for use. You should \
	148	* ensure that the IV chosen is unique: reusing an IV will \
	149	* compromise the security of the entire plaintext. This \
	150	* is equivalent to calls to @pre_init@, @pre_ofbsetkey@ \
	151	* and @pre_ofbsetiv@. \
	152	*/ \
	153	\
79ba130c	154	extern void pre##_ofbinit(pre##_ofbctx /ctx*/, \
	155	const void /key/, size_t /sz*/, \
	156	const void /iv*/); \
d03ab969	157	\
	158	/* --- @pre_ofbencrypt@ --- * \
	159	* \
	160	* Arguments: @pre_ofbctx *ctx@ = pointer to OFB context block \
	161	* @const void *src@ = pointer to source data \
	162	* @void *dest@ = pointer to destination data \
	163	* @size_t sz@ = size of block to be encrypted \
	164	* \
	165	* Returns: --- \
	166	* \
	167	* Use: Encrypts or decrypts a block with a block cipher in OFB \
	168	* mode: encryption and decryption are the same in OFB. \
	169	* The destination may be null to just churn the feedback \
	170	* round for a bit. The source may be null to use the \
	171	* cipher as a random data generator. \
	172	*/ \
	173	\
79ba130c	174	extern void pre##_ofbencrypt(pre##_ofbctx /ctx*/, \
	175	const void /src/, void /dest/, \
	176	size_t /sz/); \
d03ab969	177	\
79ba130c	178	/* --- @pre_ofbrand@ --- * \
	179	* \
	180	* Arguments: @const void *k@ = pointer to key material \
	181	* @size_t sz@ = size of key material \
	182	* \
	183	* Returns: Pointer to generic random number generator interface. \
	184	* \
	185	* Use: Creates a random number interface wrapper around an \
	186	* OFB-mode block cipher. \
	187	*/ \
d03ab969	188	\
79ba130c	189	extern grand pre##_ofbrand(const void /k/, size_t /sz/); \
d03ab969	190	\
79ba130c	191	/* --- Generic cipher interface --- */ \
d03ab969	192	\
79ba130c	193	extern const gccipher pre##_ofb;
d03ab969	194
	195	/----- That's all, folks -------------------------------------------------/
	196
	197	#ifdef __cplusplus
	198	}
	199	#endif
	200
	201	#endif