1 /* $OpenBSD: hm_ameth.c,v 1.20 2024/01/04 17:01:26 tb Exp $ */
2 /* Written by Dr Stephen N Henson (steve@openssl.org) for the OpenSSL
3 * project 2007.
4 */
5 /* ====================================================================
6 * Copyright (c) 2007 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 * licensing@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 <limits.h>
60 #include <stdio.h>
61 #include <string.h>
62
63 #include <openssl/evp.h>
64 #include <openssl/hmac.h>
65
66 #include "asn1_local.h"
67 #include "bytestring.h"
68 #include "evp_local.h"
69 #include "hmac_local.h"
70
71 static int
hmac_pkey_public_cmp(const EVP_PKEY * a,const EVP_PKEY * b)72 hmac_pkey_public_cmp(const EVP_PKEY *a, const EVP_PKEY *b)
73 {
74 /* The ameth pub_cmp must return 1 on match, 0 on mismatch. */
75 return ASN1_OCTET_STRING_cmp(a->pkey.ptr, b->pkey.ptr) == 0;
76 }
77
78 static int
hmac_size(const EVP_PKEY * pkey)79 hmac_size(const EVP_PKEY *pkey)
80 {
81 return EVP_MAX_MD_SIZE;
82 }
83
84 static void
hmac_key_free(EVP_PKEY * pkey)85 hmac_key_free(EVP_PKEY *pkey)
86 {
87 ASN1_OCTET_STRING *os;
88
89 if ((os = pkey->pkey.ptr) == NULL)
90 return;
91
92 if (os->data != NULL)
93 explicit_bzero(os->data, os->length);
94
95 ASN1_OCTET_STRING_free(os);
96 }
97
98 static int
hmac_pkey_ctrl(EVP_PKEY * pkey,int op,long arg1,void * arg2)99 hmac_pkey_ctrl(EVP_PKEY *pkey, int op, long arg1, void *arg2)
100 {
101 switch (op) {
102 case ASN1_PKEY_CTRL_DEFAULT_MD_NID:
103 *(int *)arg2 = NID_sha1;
104 return 1;
105 default:
106 return -2;
107 }
108 }
109
110 static int
hmac_set_priv_key(EVP_PKEY * pkey,const unsigned char * priv,size_t len)111 hmac_set_priv_key(EVP_PKEY *pkey, const unsigned char *priv, size_t len)
112 {
113 ASN1_OCTET_STRING *os = NULL;
114
115 if (pkey->pkey.ptr != NULL)
116 goto err;
117
118 if (len > INT_MAX)
119 goto err;
120
121 if ((os = ASN1_OCTET_STRING_new()) == NULL)
122 goto err;
123
124 if (!ASN1_OCTET_STRING_set(os, priv, len))
125 goto err;
126
127 pkey->pkey.ptr = os;
128
129 return 1;
130
131 err:
132 ASN1_OCTET_STRING_free(os);
133
134 return 0;
135 }
136
137 static int
hmac_get_priv_key(const EVP_PKEY * pkey,unsigned char * priv,size_t * len)138 hmac_get_priv_key(const EVP_PKEY *pkey, unsigned char *priv, size_t *len)
139 {
140 ASN1_OCTET_STRING *os;
141 CBS cbs;
142
143 if ((os = pkey->pkey.ptr) == NULL)
144 return 0;
145
146 if (priv == NULL) {
147 *len = os->length;
148 return 1;
149 }
150
151 CBS_init(&cbs, os->data, os->length);
152 return CBS_write_bytes(&cbs, priv, *len, len);
153 }
154
155 const EVP_PKEY_ASN1_METHOD hmac_asn1_meth = {
156 .base_method = &hmac_asn1_meth,
157 .pkey_id = EVP_PKEY_HMAC,
158
159 .pem_str = "HMAC",
160 .info = "OpenSSL HMAC method",
161
162 .pub_cmp = hmac_pkey_public_cmp,
163
164 .pkey_size = hmac_size,
165
166 .pkey_free = hmac_key_free,
167 .pkey_ctrl = hmac_pkey_ctrl,
168
169 .set_priv_key = hmac_set_priv_key,
170 .get_priv_key = hmac_get_priv_key,
171 };
172