rsa_x931.c revision 296465 
1/* rsa_x931.c */
2/*
3 * Written by Dr Stephen N Henson (steve@openssl.org) for the OpenSSL project
4 * 2005.
5 */
6/* ====================================================================
7 * Copyright (c) 2005 The OpenSSL Project.  All rights reserved.
8 *
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
11 * are met:
12 *
13 * 1. Redistributions of source code must retain the above copyright
14 *    notice, this list of conditions and the following disclaimer.
15 *
16 * 2. Redistributions in binary form must reproduce the above copyright
17 *    notice, this list of conditions and the following disclaimer in
18 *    the documentation and/or other materials provided with the
19 *    distribution.
20 *
21 * 3. All advertising materials mentioning features or use of this
22 *    software must display the following acknowledgment:
23 *    "This product includes software developed by the OpenSSL Project
24 *    for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)"
25 *
26 * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
27 *    endorse or promote products derived from this software without
28 *    prior written permission. For written permission, please contact
29 *    licensing@OpenSSL.org.
30 *
31 * 5. Products derived from this software may not be called "OpenSSL"
32 *    nor may "OpenSSL" appear in their names without prior written
33 *    permission of the OpenSSL Project.
34 *
35 * 6. Redistributions of any form whatsoever must retain the following
36 *    acknowledgment:
37 *    "This product includes software developed by the OpenSSL Project
38 *    for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)"
39 *
40 * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
41 * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
42 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
43 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
44 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
45 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
46 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
47 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
48 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
49 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
50 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
51 * OF THE POSSIBILITY OF SUCH DAMAGE.
52 * ====================================================================
53 *
54 * This product includes cryptographic software written by Eric Young
55 * (eay@cryptsoft.com).  This product includes software written by Tim
56 * Hudson (tjh@cryptsoft.com).
57 *
58 */
59
60#include <stdio.h>
61#include "cryptlib.h"
62#include <openssl/bn.h>
63#include <openssl/rsa.h>
64#include <openssl/rand.h>
65#include <openssl/objects.h>
66
67int RSA_padding_add_X931(unsigned char *to, int tlen,
68                         const unsigned char *from, int flen)
69{
70    int j;
71    unsigned char *p;
72
73    /*
74     * Absolute minimum amount of padding is 1 header nibble, 1 padding
75     * nibble and 2 trailer bytes: but 1 hash if is already in 'from'.
76     */
77
78    j = tlen - flen - 2;
79
80    if (j < 0) {
81        RSAerr(RSA_F_RSA_PADDING_ADD_X931, RSA_R_DATA_TOO_LARGE_FOR_KEY_SIZE);
82        return -1;
83    }
84
85    p = (unsigned char *)to;
86
87    /* If no padding start and end nibbles are in one byte */
88    if (j == 0)
89        *p++ = 0x6A;
90    else {
91        *p++ = 0x6B;
92        if (j > 1) {
93            memset(p, 0xBB, j - 1);
94            p += j - 1;
95        }
96        *p++ = 0xBA;
97    }
98    memcpy(p, from, (unsigned int)flen);
99    p += flen;
100    *p = 0xCC;
101    return (1);
102}
103
104int RSA_padding_check_X931(unsigned char *to, int tlen,
105                           const unsigned char *from, int flen, int num)
106{
107    int i = 0, j;
108    const unsigned char *p;
109
110    p = from;
111    if ((num != flen) || ((*p != 0x6A) && (*p != 0x6B))) {
112        RSAerr(RSA_F_RSA_PADDING_CHECK_X931, RSA_R_INVALID_HEADER);
113        return -1;
114    }
115
116    if (*p++ == 0x6B) {
117        j = flen - 3;
118        for (i = 0; i < j; i++) {
119            unsigned char c = *p++;
120            if (c == 0xBA)
121                break;
122            if (c != 0xBB) {
123                RSAerr(RSA_F_RSA_PADDING_CHECK_X931, RSA_R_INVALID_PADDING);
124                return -1;
125            }
126        }
127
128        j -= i;
129
130        if (i == 0) {
131            RSAerr(RSA_F_RSA_PADDING_CHECK_X931, RSA_R_INVALID_PADDING);
132            return -1;
133        }
134
135    } else
136        j = flen - 2;
137
138    if (p[j] != 0xCC) {
139        RSAerr(RSA_F_RSA_PADDING_CHECK_X931, RSA_R_INVALID_TRAILER);
140        return -1;
141    }
142
143    memcpy(to, p, (unsigned int)j);
144
145    return (j);
146}
147
148/* Translate between X931 hash ids and NIDs */
149
150int RSA_X931_hash_id(int nid)
151{
152    switch (nid) {
153    case NID_sha1:
154        return 0x33;
155
156    case NID_sha256:
157        return 0x34;
158
159    case NID_sha384:
160        return 0x36;
161
162    case NID_sha512:
163        return 0x35;
164
165    }
166    return -1;
167}
168