1 /* $OpenBSD: mac.c,v 1.11 2006/07/22 20:48:23 stevesk Exp $ */
3 * Copyright (c) 2001 Markus Friedl. All rights reserved.
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
15 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
16 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
17 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
18 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
19 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
20 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
21 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
22 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
23 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
28 #include <openssl/hmac.h>
41 const EVP_MD * (*mdfunc)(void);
42 int truncatebits; /* truncate digest if != 0 */
44 { "hmac-sha1", EVP_sha1, 0, },
45 { "hmac-sha1-96", EVP_sha1, 96 },
46 { "hmac-md5", EVP_md5, 0 },
47 { "hmac-md5-96", EVP_md5, 96 },
48 { "hmac-ripemd160", EVP_ripemd160, 0 },
49 { "hmac-ripemd160@openssh.com", EVP_ripemd160, 0 },
54 mac_init(Mac *mac, char *name)
58 for (i = 0; macs[i].name; i++) {
59 if (strcmp(name, macs[i].name) == 0) {
61 mac->md = (*macs[i].mdfunc)();
62 if ((evp_len = EVP_MD_size(mac->md)) <= 0)
63 fatal("mac %s len %d", name, evp_len);
64 mac->key_len = mac->mac_len = (u_int)evp_len;
65 if (macs[i].truncatebits != 0)
66 mac->mac_len = macs[i].truncatebits/8;
68 debug2("mac_init: found %s", name);
72 debug2("mac_init: unknown %s", name);
77 mac_compute(Mac *mac, u_int32_t seqno, u_char *data, int datalen)
80 static u_char m[EVP_MAX_MD_SIZE];
84 fatal("mac_compute: no key");
85 if (mac->mac_len > sizeof(m))
86 fatal("mac_compute: mac too long");
87 HMAC_Init(&c, mac->key, mac->key_len, mac->md);
89 HMAC_Update(&c, b, sizeof(b));
90 HMAC_Update(&c, data, datalen);
91 HMAC_Final(&c, m, NULL);
96 /* XXX copied from ciphers_valid */
99 mac_valid(const char *names)
101 char *maclist, *cp, *p;
103 if (names == NULL || strcmp(names, "") == 0)
105 maclist = cp = xstrdup(names);
106 for ((p = strsep(&cp, MAC_SEP)); p && *p != '\0';
107 (p = strsep(&cp, MAC_SEP))) {
108 if (mac_init(NULL, p) < 0) {
109 debug("bad mac %s [%s]", p, names);
113 debug3("mac ok: %s [%s]", p, names);
116 debug3("macs ok: [%s]", names);