rsa_ssl.c revision 296465 
1/* crypto/rsa/rsa_ssl.c */
2/* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
3 * All rights reserved.
4 *
5 * This package is an SSL implementation written
6 * by Eric Young (eay@cryptsoft.com).
7 * The implementation was written so as to conform with Netscapes SSL.
8 *
9 * This library is free for commercial and non-commercial use as long as
10 * the following conditions are aheared to.  The following conditions
11 * apply to all code found in this distribution, be it the RC4, RSA,
12 * lhash, DES, etc., code; not just the SSL code.  The SSL documentation
13 * included with this distribution is covered by the same copyright terms
14 * except that the holder is Tim Hudson (tjh@cryptsoft.com).
15 *
16 * Copyright remains Eric Young's, and as such any Copyright notices in
17 * the code are not to be removed.
18 * If this package is used in a product, Eric Young should be given attribution
19 * as the author of the parts of the library used.
20 * This can be in the form of a textual message at program startup or
21 * in documentation (online or textual) provided with the package.
22 *
23 * Redistribution and use in source and binary forms, with or without
24 * modification, are permitted provided that the following conditions
25 * are met:
26 * 1. Redistributions of source code must retain the copyright
27 *    notice, this list of conditions and the following disclaimer.
28 * 2. Redistributions in binary form must reproduce the above copyright
29 *    notice, this list of conditions and the following disclaimer in the
30 *    documentation and/or other materials provided with the distribution.
31 * 3. All advertising materials mentioning features or use of this software
32 *    must display the following acknowledgement:
33 *    "This product includes cryptographic software written by
34 *     Eric Young (eay@cryptsoft.com)"
35 *    The word 'cryptographic' can be left out if the rouines from the library
36 *    being used are not cryptographic related :-).
37 * 4. If you include any Windows specific code (or a derivative thereof) from
38 *    the apps directory (application code) you must include an acknowledgement:
39 *    "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
40 *
41 * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
42 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
43 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
44 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
45 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
46 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
47 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
48 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
49 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
50 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
51 * SUCH DAMAGE.
52 *
53 * The licence and distribution terms for any publically available version or
54 * derivative of this code cannot be changed.  i.e. this code cannot simply be
55 * copied and put under another distribution licence
56 * [including the GNU Public Licence.]
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
65int RSA_padding_add_SSLv23(unsigned char *to, int tlen,
66                           const unsigned char *from, int flen)
67{
68    int i, j;
69    unsigned char *p;
70
71    if (flen > (tlen - 11)) {
72        RSAerr(RSA_F_RSA_PADDING_ADD_SSLV23,
73               RSA_R_DATA_TOO_LARGE_FOR_KEY_SIZE);
74        return (0);
75    }
76
77    p = (unsigned char *)to;
78
79    *(p++) = 0;
80    *(p++) = 2;                 /* Public Key BT (Block Type) */
81
82    /* pad out with non-zero random data */
83    j = tlen - 3 - 8 - flen;
84
85    if (RAND_bytes(p, j) <= 0)
86        return (0);
87    for (i = 0; i < j; i++) {
88        if (*p == '\0')
89            do {
90                if (RAND_bytes(p, 1) <= 0)
91                    return (0);
92            } while (*p == '\0');
93        p++;
94    }
95
96    memset(p, 3, 8);
97    p += 8;
98    *(p++) = '\0';
99
100    memcpy(p, from, (unsigned int)flen);
101    return (1);
102}
103
104int RSA_padding_check_SSLv23(unsigned char *to, int tlen,
105                             const unsigned char *from, int flen, int num)
106{
107    int i, j, k;
108    const unsigned char *p;
109
110    p = from;
111    if (flen < 10) {
112        RSAerr(RSA_F_RSA_PADDING_CHECK_SSLV23, RSA_R_DATA_TOO_SMALL);
113        return (-1);
114    }
115    if ((num != (flen + 1)) || (*(p++) != 02)) {
116        RSAerr(RSA_F_RSA_PADDING_CHECK_SSLV23, RSA_R_BLOCK_TYPE_IS_NOT_02);
117        return (-1);
118    }
119
120    /* scan over padding data */
121    j = flen - 1;               /* one for type */
122    for (i = 0; i < j; i++)
123        if (*(p++) == 0)
124            break;
125
126    if ((i == j) || (i < 8)) {
127        RSAerr(RSA_F_RSA_PADDING_CHECK_SSLV23,
128               RSA_R_NULL_BEFORE_BLOCK_MISSING);
129        return (-1);
130    }
131    for (k = -9; k < -1; k++) {
132        if (p[k] != 0x03)
133            break;
134    }
135    if (k == -1) {
136        RSAerr(RSA_F_RSA_PADDING_CHECK_SSLV23, RSA_R_SSLV3_ROLLBACK_ATTACK);
137        return (-1);
138    }
139
140    i++;                        /* Skip over the '\0' */
141    j -= i;
142    if (j > tlen) {
143        RSAerr(RSA_F_RSA_PADDING_CHECK_SSLV23, RSA_R_DATA_TOO_LARGE);
144        return (-1);
145    }
146    memcpy(to, p, (unsigned int)j);
147
148    return (j);
149}
150