1/* $OpenBSD: rsa_saos.c,v 1.25 2023/07/08 12:26:45 beck Exp $ */
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 <string.h>
61
62#include <openssl/bn.h>
63#include <openssl/err.h>
64#include <openssl/objects.h>
65#include <openssl/rsa.h>
66#include <openssl/x509.h>
67
68int
69RSA_sign_ASN1_OCTET_STRING(int type, const unsigned char *m, unsigned int m_len,
70    unsigned char *sigret, unsigned int *siglen, RSA *rsa)
71{
72	ASN1_OCTET_STRING sig;
73	int i, j, ret = 1;
74	unsigned char *p, *s;
75
76	sig.type = V_ASN1_OCTET_STRING;
77	sig.length = m_len;
78	sig.data = (unsigned char *)m;
79
80	i = i2d_ASN1_OCTET_STRING(&sig, NULL);
81	j = RSA_size(rsa);
82	if (i > (j - RSA_PKCS1_PADDING_SIZE)) {
83		RSAerror(RSA_R_DIGEST_TOO_BIG_FOR_RSA_KEY);
84		return 0;
85	}
86	s = malloc(j + 1);
87	if (s == NULL) {
88		RSAerror(ERR_R_MALLOC_FAILURE);
89		return 0;
90	}
91	p = s;
92	i2d_ASN1_OCTET_STRING(&sig, &p);
93	i = RSA_private_encrypt(i, s, sigret, rsa, RSA_PKCS1_PADDING);
94	if (i <= 0)
95		ret = 0;
96	else
97		*siglen = i;
98
99	freezero(s, (unsigned int)j + 1);
100	return ret;
101}
102LCRYPTO_ALIAS(RSA_sign_ASN1_OCTET_STRING);
103
104int
105RSA_verify_ASN1_OCTET_STRING(int dtype, const unsigned char *m,
106    unsigned int m_len, unsigned char *sigbuf, unsigned int siglen, RSA *rsa)
107{
108	int i, ret = 0;
109	unsigned char *s;
110	const unsigned char *p;
111	ASN1_OCTET_STRING *sig = NULL;
112
113	if (siglen != (unsigned int)RSA_size(rsa)) {
114		RSAerror(RSA_R_WRONG_SIGNATURE_LENGTH);
115		return 0;
116	}
117
118	s = malloc(siglen);
119	if (s == NULL) {
120		RSAerror(ERR_R_MALLOC_FAILURE);
121		goto err;
122	}
123	i = RSA_public_decrypt((int)siglen, sigbuf, s, rsa, RSA_PKCS1_PADDING);
124
125	if (i <= 0)
126		goto err;
127
128	p = s;
129	sig = d2i_ASN1_OCTET_STRING(NULL, &p, (long)i);
130	if (sig == NULL)
131		goto err;
132
133	if ((unsigned int)sig->length != m_len ||
134	    timingsafe_bcmp(m, sig->data, m_len) != 0) {
135		RSAerror(RSA_R_BAD_SIGNATURE);
136	} else
137		ret = 1;
138err:
139	ASN1_OCTET_STRING_free(sig);
140	freezero(s, (unsigned int)siglen);
141	return ret;
142}
143LCRYPTO_ALIAS(RSA_verify_ASN1_OCTET_STRING);
144