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 
66 int 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 
105 int 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 
158 int 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