1 /* $OpenBSD: ecs_vrf.c,v 1.4 2015/01/28 04:14:31 beck Exp $ */
2 /*
3  * Written by Nils Larsch for the OpenSSL project
4  */
5 /* ====================================================================
6  * Copyright (c) 1998-2002 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  *    openssl-core@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 <string.h>
60 #include <openssl/opensslconf.h>
61 
62 #include "ecs_locl.h"
63 #ifndef OPENSSL_NO_ENGINE
64 #include <openssl/engine.h>
65 #endif
66 
67 /* returns
68  *      1: correct signature
69  *      0: incorrect signature
70  *     -1: error
71  */
72 int
73 ECDSA_do_verify(const unsigned char *dgst, int dgst_len, const ECDSA_SIG *sig,
74     EC_KEY *eckey)
75 {
76 	ECDSA_DATA *ecdsa = ecdsa_check(eckey);
77 
78 	if (ecdsa == NULL)
79 		return 0;
80 	return ecdsa->meth->ecdsa_do_verify(dgst, dgst_len, sig, eckey);
81 }
82 
83 /* returns
84  *      1: correct signature
85  *      0: incorrect signature
86  *     -1: error
87  */
88 int
89 ECDSA_verify(int type, const unsigned char *dgst, int dgst_len,
90     const unsigned char *sigbuf, int sig_len, EC_KEY *eckey)
91 {
92 	ECDSA_SIG *s;
93 	unsigned char *der = NULL;
94 	const unsigned char *p = sigbuf;
95 	int derlen = -1;
96 	int ret = -1;
97 
98 	s = ECDSA_SIG_new();
99 	if (s == NULL)
100 		return (ret);
101 	if (d2i_ECDSA_SIG(&s, &p, sig_len) == NULL)
102 		goto err;
103 	/* Ensure signature uses DER and doesn't have trailing garbage */
104 	derlen = i2d_ECDSA_SIG(s, &der);
105 	if (derlen != sig_len || memcmp(sigbuf, der, derlen))
106 		goto err;
107 	ret = ECDSA_do_verify(dgst, dgst_len, s, eckey);
108 
109 err:
110 	if (derlen > 0) {
111 		explicit_bzero(der, derlen);
112 		free(der);
113 	}
114 	ECDSA_SIG_free(s);
115 	return (ret);
116 }
117