[u/mdw/catacomb] / pkcs1.c

/* -*-c-*-
 *
 * $Id: pkcs1.c,v 1.3 2000/10/08 12:07:04 mdw Exp $
 *
 * PKCS#1 1.5 packing
 *
 * (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: pkcs1.c,v $
 * Revision 1.3  2000/10/08 12:07:04  mdw
 * Don't do arithmetic on @void *@ pointers.
 *
 * Revision 1.2  2000/07/05 17:49:48  mdw
 * Fix decoding functions, so that they don't run off the end of the
 * buffer.
 *
 * Revision 1.1  2000/07/01 11:17:38  mdw
 * New support for PKCS#1 message encoding.
 *
 */

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

#include <string.h>

#include <mLib/bits.h>
#include <mLib/dstr.h>

#include "grand.h"
#include "pkcs1.h"

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

/* --- @pkcs1_cryptencode@ --- *
 *
 * Arguments:	@const void *msg@ = pointer to message data
 *		@size_t msz@ = size of message data
 *		@void *buf@ = pointer to output buffer
 *		@size_t sz@ = size of the output buffer
 *		@void *p@ = pointer to PKCS1 parameter block
 *
 * Returns:	Zero if all went well, negative on failure.
 *
 * Use:		Implements the operation @EME-PKCS1-V1_5-ENCODE@, as defined
 *		in PKCS#1 v. 2.0 (RFC2437).
 */

int pkcs1_cryptencode(const void *msg, size_t msz, void *buf, size_t sz,
		      void *p)
{
  pkcs1 *pp = p;
  grand *r = pp->r;
  octet *q, *qq;
  size_t i, n;

  /* --- Ensure that the buffer is sensibly sized --- */

  if (pp->epsz + msz + 11 > sz)
    return (-1);

  /* --- Fill in the buffer --- */

  q = buf;
  qq = q + sz;
  *q++ = 0;
  *q++ = 2;
  n = sz - msz - pp->epsz - 3;
  r->ops->fill(r, q, n);
  for (i = 0; i < n; i++) {
    if (*q == 0)
      *q = r->ops->range(r, 255) + 1;
    q++;
  }
  *q++ = 0;
  memcpy(q, pp->ep, pp->epsz);
  q += pp->epsz;
  memcpy(q, msg, msz);
  return (0);
}

/* --- @pkcs1_cryptdecode@ --- *
 *
 * Arguments:	@const void *buf@ = pointer to encoded buffer
 *		@size_t sz@ = size of the encoded buffer
 *		@dstr *d@ = pointer to destination string
 *		@void *p@ = pointer to PKCS1 parameter block
 *
 * Returns:	The length of the output string if successful, negative on
 *		failure.
 *
 * Use:		Implements the operation @EME-PKCS1-V1_5-DECODE@, as defined
 *		in PKCS#1 v. 2.0 (RFC2437).
 */

int pkcs1_cryptdecode(const void *buf, size_t sz, dstr *d, void *p)
{
  pkcs1 *pp = p;
  const octet *q, *qq;
  size_t n, i;

  /* --- Check the size of the block looks sane --- */

  if (pp->epsz + 11 > sz)
    return (-1);
  q = buf;
  qq = q + sz;

  /* --- Ensure that the block looks OK --- */

  if (*q++ != 0 || *q++ != 2)
    return (-1);

  /* --- Check the nonzero padding --- */

  i = 0;
  while (*q != 0 && q < qq)
    i++, q++;
  if (i < 8 || qq - q < pp->epsz + 1)
    return (-1);
  q++;

  /* --- Check the encoding parameters --- */

  if (memcmp(q, pp->ep, pp->epsz) != 0)
    return (-1);
  q += pp->epsz;

  /* --- Done --- */

  n = qq - q;
  dstr_putm(d, q, n);
  return (n);
}

/* --- @pkcs1_sigencode@ --- *
 *
 * Arguments:	@const void *msg@ = pointer to message data
 *		@size_t msz@ = size of message data
 *		@void *buf@ = pointer to output buffer
 *		@size_t sz@ = size of the output buffer
 *		@void *p@ = pointer to PKCS1 parameter block
 *
 * Returns:	Zero if all went well, negative on failure.
 *
 * Use:		Implements the operation @EMSA-PKCS1-V1_5-ENCODE@, as defined
 *		in PKCS#1 v. 2.0 (RFC2437).
 */

int pkcs1_sigencode(const void *msg, size_t msz, void *buf, size_t sz,
		      void *p)
{
  pkcs1 *pp = p;
  octet *q, *qq;
  size_t n;

  /* --- Ensure that the buffer is sensibly sized --- */

  if (pp->epsz + msz + 11 > sz)
    return (-1);

  /* --- Fill in the buffer --- */

  q = buf;
  qq = q + sz;
  *q++ = 0;
  *q++ = 1;
  n = sz - msz - pp->epsz - 3;
  memset(q, 0xff, n);
  q += n;
  *q++ = 0;
  memcpy(q, pp->ep, pp->epsz);
  q += pp->epsz;
  memcpy(q, msg, msz);
  return (0);
}

/* --- @pkcs1_sigdecode@ --- *
 *
 * Arguments:	@const void *buf@ = pointer to encoded buffer
 *		@size_t sz@ = size of the encoded buffer
 *		@dstr *d@ = pointer to destination string
 *		@void *p@ = pointer to PKCS1 parameter block
 *
 * Returns:	The length of the output string if successful, negative on
 *		failure.
 *
 * Use:		Implements the operation @EMSA-PKCS1-V1_5-DECODE@, as defined
 *		in PKCS#1 v. 2.0 (RFC2437).
 */

int pkcs1_sigdecode(const void *buf, size_t sz, dstr *d, void *p)
{
  pkcs1 *pp = p;
  const octet *q, *qq;
  size_t i, n;

  /* --- Check the size of the block looks sane --- */

  if (pp->epsz + 10 > sz)
    return (-1);
  q = buf;
  qq = q + sz;

  /* --- Ensure that the block looks OK --- */

  if (*q++ != 0 || *q++ != 1)
    return (-1);

  /* --- Check the padding --- */

  i = 0;
  while (*q == 0xff && q < qq)
    i++, q++;
  if (i < 8 || qq - q < pp->epsz + 1 || *q++ != 0)
    return (-1);

  /* --- Check the encoding parameters --- */

  if (memcmp(q, pp->ep, pp->epsz) != 0)
    return (-1);
  q += pp->epsz;

  /* --- Done --- */

  n = qq - q;
  dstr_putm(d, q, n);
  return (n);
}

/*----- That's all, folks -------------------------------------------------*/
Commit	Line	Data
cd6c3eeb	1	/* --c--
cd6c3eeb	2	*
7629bca8	3	* $Id: pkcs1.c,v 1.3 2000/10/08 12:07:04 mdw Exp $
cd6c3eeb	4	*
	5	* PKCS#1 1.5 packing
	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: pkcs1.c,v $
7629bca8	33	* Revision 1.3 2000/10/08 12:07:04 mdw
	34	* Don't do arithmetic on @void *@ pointers.
	35	*
0586d2a1	36	* Revision 1.2 2000/07/05 17:49:48 mdw
	37	* Fix decoding functions, so that they don't run off the end of the
	38	* buffer.
	39	*
cd6c3eeb	40	* Revision 1.1 2000/07/01 11:17:38 mdw
	41	* New support for PKCS#1 message encoding.
	42	*
	43	*/
	44
	45	/----- Header files ------------------------------------------------------/
	46
	47	#include <string.h>
	48
	49	#include <mLib/bits.h>
	50	#include <mLib/dstr.h>
	51
	52	#include "grand.h"
	53	#include "pkcs1.h"
	54
	55	/----- Main code ---------------------------------------------------------/
	56
	57	/* --- @pkcs1_cryptencode@ --- *
	58	*
	59	* Arguments: @const void *msg@ = pointer to message data
	60	* @size_t msz@ = size of message data
	61	* @void *buf@ = pointer to output buffer
	62	* @size_t sz@ = size of the output buffer
	63	* @void *p@ = pointer to PKCS1 parameter block
	64	*
	65	* Returns: Zero if all went well, negative on failure.
	66	*
	67	* Use: Implements the operation @EME-PKCS1-V1_5-ENCODE@, as defined
	68	* in PKCS#1 v. 2.0 (RFC2437).
	69	*/
	70
	71	int pkcs1_cryptencode(const void msg, size_t msz, void buf, size_t sz,
	72	void *p)
	73	{
	74	pkcs1 *pp = p;
	75	grand *r = pp->r;
	76	octet q, qq;
	77	size_t i, n;
	78
	79	/* --- Ensure that the buffer is sensibly sized --- */
	80
	81	if (pp->epsz + msz + 11 > sz)
	82	return (-1);
	83
	84	/* --- Fill in the buffer --- */
	85
	86	q = buf;
	87	qq = q + sz;
	88	*q++ = 0;
	89	*q++ = 2;
	90	n = sz - msz - pp->epsz - 3;
	91	r->ops->fill(r, q, n);
	92	for (i = 0; i < n; i++) {
	93	if (*q == 0)
	94	*q = r->ops->range(r, 255) + 1;
	95	q++;
	96	}
	97	*q++ = 0;
	98	memcpy(q, pp->ep, pp->epsz);
	99	q += pp->epsz;
	100	memcpy(q, msg, msz);
	101	return (0);
	102	}
	103
104	/* --- @pkcs1_cryptdecode@ --- *
105	*
106	* Arguments: @const void *buf@ = pointer to encoded buffer
107	* @size_t sz@ = size of the encoded buffer
108	* @dstr *d@ = pointer to destination string
109	* @void *p@ = pointer to PKCS1 parameter block
110	*
111	* Returns: The length of the output string if successful, negative on
112	* failure.
113	*
114	* Use: Implements the operation @EME-PKCS1-V1_5-DECODE@, as defined
115	* in PKCS#1 v. 2.0 (RFC2437).
116	*/
117
118	int pkcs1_cryptdecode(const void buf, size_t sz, dstr d, void *p)
119	{
120	pkcs1 *pp = p;
121	const octet q, qq;
122	size_t n, i;
123
124	/* --- Check the size of the block looks sane --- */
125
126	if (pp->epsz + 11 > sz)
127	return (-1);
128	q = buf;
7629bca8	129	qq = q + sz;
cd6c3eeb	130
	131	/* --- Ensure that the block looks OK --- */
	132
	133	if (q++ != 0 \|\| q++ != 2)
	134	return (-1);
	135
	136	/* --- Check the nonzero padding --- */
	137
	138	i = 0;
	139	while (*q != 0 && q < qq)
	140	i++, q++;
0586d2a1	141	if (i < 8 \|\| qq - q < pp->epsz + 1)
cd6c3eeb	142	return (-1);
	143	q++;
	144
	145	/* --- Check the encoding parameters --- */
	146
	147	if (memcmp(q, pp->ep, pp->epsz) != 0)
	148	return (-1);
	149	q += pp->epsz;
	150
	151	/* --- Done --- */
	152
	153	n = qq - q;
	154	dstr_putm(d, q, n);
	155	return (n);
	156	}
	157
	158	/* --- @pkcs1_sigencode@ --- *
	159	*
	160	* Arguments: @const void *msg@ = pointer to message data
	161	* @size_t msz@ = size of message data
	162	* @void *buf@ = pointer to output buffer
	163	* @size_t sz@ = size of the output buffer
	164	* @void *p@ = pointer to PKCS1 parameter block
	165	*
	166	* Returns: Zero if all went well, negative on failure.
	167	*
	168	* Use: Implements the operation @EMSA-PKCS1-V1_5-ENCODE@, as defined
	169	* in PKCS#1 v. 2.0 (RFC2437).
	170	*/
	171
	172	int pkcs1_sigencode(const void msg, size_t msz, void buf, size_t sz,
	173	void *p)
	174	{
	175	pkcs1 *pp = p;
	176	octet q, qq;
	177	size_t n;
	178
	179	/* --- Ensure that the buffer is sensibly sized --- */
	180
	181	if (pp->epsz + msz + 11 > sz)
	182	return (-1);
	183
	184	/* --- Fill in the buffer --- */
	185
	186	q = buf;
	187	qq = q + sz;
	188	*q++ = 0;
	189	*q++ = 1;
	190	n = sz - msz - pp->epsz - 3;
	191	memset(q, 0xff, n);
	192	q += n;
	193	*q++ = 0;
	194	memcpy(q, pp->ep, pp->epsz);
	195	q += pp->epsz;
	196	memcpy(q, msg, msz);
	197	return (0);
	198	}
	199
	200	/* --- @pkcs1_sigdecode@ --- *
	201	*
	202	* Arguments: @const void *buf@ = pointer to encoded buffer
	203	* @size_t sz@ = size of the encoded buffer
	204	* @dstr *d@ = pointer to destination string
	205	* @void *p@ = pointer to PKCS1 parameter block
206	*
207	* Returns: The length of the output string if successful, negative on
208	* failure.
209	*
210	* Use: Implements the operation @EMSA-PKCS1-V1_5-DECODE@, as defined
211	* in PKCS#1 v. 2.0 (RFC2437).
212	*/
213
214	int pkcs1_sigdecode(const void buf, size_t sz, dstr d, void *p)
215	{
216	pkcs1 *pp = p;
217	const octet q, qq;
218	size_t i, n;
219
220	/* --- Check the size of the block looks sane --- */
221
222	if (pp->epsz + 10 > sz)
223	return (-1);
224	q = buf;
7629bca8	225	qq = q + sz;
cd6c3eeb	226
	227	/* --- Ensure that the block looks OK --- */
	228
	229	if (q++ != 0 \|\| q++ != 1)
	230	return (-1);
	231
	232	/* --- Check the padding --- */
	233
	234	i = 0;
	235	while (*q == 0xff && q < qq)
	236	i++, q++;
0586d2a1	237	if (i < 8 \|\| qq - q < pp->epsz + 1 \|\| *q++ != 0)
cd6c3eeb	238	return (-1);
cd6c3eeb	239
	240	/* --- Check the encoding parameters --- */
	241
	242	if (memcmp(q, pp->ep, pp->epsz) != 0)
	243	return (-1);
	244	q += pp->epsz;
	245
	246	/* --- Done --- */
	247
	248	n = qq - q;
	249	dstr_putm(d, q, n);
	250	return (n);
	251	}
	252
	253	/----- That's all, folks -------------------------------------------------/