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		{
73		RSAerr(RSA_F_RSA_PADDING_ADD_SSLV23,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		{
89		if (*p == '\0')
90			do	{
91				if (RAND_bytes(p,1) <= 0)
92					return(0);
93				} while (*p == '\0');
94		p++;
95		}
96
97	memset(p,3,8);
98	p+=8;
99	*(p++)='\0';
100
101	memcpy(p,from,(unsigned int)flen);
102	return(1);
103	}
104
105int RSA_padding_check_SSLv23(unsigned char *to, int tlen,
106	const unsigned char *from, int flen, int num)
107	{
108	int i,j,k;
109	const unsigned char *p;
110
111	p=from;
112	if (flen < 10)
113		{
114		RSAerr(RSA_F_RSA_PADDING_CHECK_SSLV23,RSA_R_DATA_TOO_SMALL);
115		return(-1);
116		}
117	if ((num != (flen+1)) || (*(p++) != 02))
118		{
119		RSAerr(RSA_F_RSA_PADDING_CHECK_SSLV23,RSA_R_BLOCK_TYPE_IS_NOT_02);
120		return(-1);
121		}
122
123	/* scan over padding data */
124	j=flen-1; /* one for type */
125	for (i=0; i<j; i++)
126		if (*(p++) == 0) break;
127
128	if ((i == j) || (i < 8))
129		{
130		RSAerr(RSA_F_RSA_PADDING_CHECK_SSLV23,RSA_R_NULL_BEFORE_BLOCK_MISSING);
131		return(-1);
132		}
133	for (k = -9; k<-1; k++)
134		{
135		if (p[k] !=  0x03) break;
136		}
137	if (k == -1)
138		{
139		RSAerr(RSA_F_RSA_PADDING_CHECK_SSLV23,RSA_R_SSLV3_ROLLBACK_ATTACK);
140		return(-1);
141		}
142
143	i++; /* Skip over the '\0' */
144	j-=i;
145	if (j > tlen)
146		{
147		RSAerr(RSA_F_RSA_PADDING_CHECK_SSLV23,RSA_R_DATA_TOO_LARGE);
148		return(-1);
149		}
150	memcpy(to,p,(unsigned int)j);
151
152	return(j);
153	}
154
155