1/* rsa_x931.c */
2/* Written by Dr Stephen N Henson (steve@openssl.org) for the OpenSSL
3 * project 2005.
4 */
5/* ====================================================================
6 * Copyright (c) 2005 The OpenSSL Project.  All rights reserved.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 *
12 * 1. Redistributions of source code must retain the above copyright
13 *    notice, this list of conditions and the following disclaimer.
14 *
15 * 2. Redistributions in binary form must reproduce the above copyright
16 *    notice, this list of conditions and the following disclaimer in
17 *    the documentation and/or other materials provided with the
18 *    distribution.
19 *
20 * 3. All advertising materials mentioning features or use of this
21 *    software must display the following acknowledgment:
22 *    "This product includes software developed by the OpenSSL Project
23 *    for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)"
24 *
25 * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
26 *    endorse or promote products derived from this software without
27 *    prior written permission. For written permission, please contact
28 *    licensing@OpenSSL.org.
29 *
30 * 5. Products derived from this software may not be called "OpenSSL"
31 *    nor may "OpenSSL" appear in their names without prior written
32 *    permission of the OpenSSL Project.
33 *
34 * 6. Redistributions of any form whatsoever must retain the following
35 *    acknowledgment:
36 *    "This product includes software developed by the OpenSSL Project
37 *    for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)"
38 *
39 * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
40 * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
41 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
42 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
43 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
44 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
45 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
46 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
47 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
48 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
49 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
50 * OF THE POSSIBILITY OF SUCH DAMAGE.
51 * ====================================================================
52 *
53 * This product includes cryptographic software written by Eric Young
54 * (eay@cryptsoft.com).  This product includes software written by Tim
55 * Hudson (tjh@cryptsoft.com).
56 *
57 */
58
59#include <stdio.h>
60#include "cryptlib.h"
61#include <openssl/bn.h>
62#include <openssl/rsa.h>
63#include <openssl/rand.h>
64#include <openssl/objects.h>
65
66int RSA_padding_add_X931(unsigned char *to, int tlen,
67	     const unsigned char *from, int flen)
68	{
69	int j;
70	unsigned char *p;
71
72	/* Absolute minimum amount of padding is 1 header nibble, 1 padding
73	 * nibble and 2 trailer bytes: but 1 hash if is already in 'from'.
74	 */
75
76	j = tlen - flen - 2;
77
78	if (j < 0)
79		{
80		RSAerr(RSA_F_RSA_PADDING_ADD_X931,RSA_R_DATA_TOO_LARGE_FOR_KEY_SIZE);
81		return -1;
82		}
83
84	p=(unsigned char *)to;
85
86	/* If no padding start and end nibbles are in one byte */
87	if (j == 0)
88		*p++ = 0x6A;
89	else
90		{
91		*p++ = 0x6B;
92		if (j > 1)
93			{
94			memset(p, 0xBB, j - 1);
95			p += j - 1;
96			}
97		*p++ = 0xBA;
98		}
99	memcpy(p,from,(unsigned int)flen);
100	p += flen;
101	*p = 0xCC;
102	return(1);
103	}
104
105int RSA_padding_check_X931(unsigned char *to, int tlen,
106	     const unsigned char *from, int flen, int num)
107	{
108	int i = 0,j;
109	const unsigned char *p;
110
111	p=from;
112	if ((num != flen) || ((*p != 0x6A) && (*p != 0x6B)))
113		{
114		RSAerr(RSA_F_RSA_PADDING_CHECK_X931,RSA_R_INVALID_HEADER);
115		return -1;
116		}
117
118	if (*p++ == 0x6B)
119		{
120		j=flen-3;
121		for (i = 0; i < j; i++)
122			{
123			unsigned char c = *p++;
124			if (c == 0xBA)
125				break;
126			if (c != 0xBB)
127				{
128				RSAerr(RSA_F_RSA_PADDING_CHECK_X931,
129					RSA_R_INVALID_PADDING);
130				return -1;
131				}
132			}
133
134		j -= i;
135
136		if (i == 0)
137			{
138			RSAerr(RSA_F_RSA_PADDING_CHECK_X931, RSA_R_INVALID_PADDING);
139			return -1;
140			}
141
142		}
143	else j = flen - 2;
144
145	if (p[j] != 0xCC)
146		{
147		RSAerr(RSA_F_RSA_PADDING_CHECK_X931, RSA_R_INVALID_TRAILER);
148		return -1;
149		}
150
151	memcpy(to,p,(unsigned int)j);
152
153	return(j);
154	}
155
156/* Translate between X931 hash ids and NIDs */
157
158int RSA_X931_hash_id(int nid)
159	{
160	switch (nid)
161		{
162		case NID_sha1:
163		return 0x33;
164
165		case NID_sha256:
166		return 0x34;
167
168		case NID_sha384:
169		return 0x36;
170
171		case NID_sha512:
172		return 0x35;
173
174		}
175	return -1;
176	}
177
178