2 * Copyright (c) 2001 Markus Friedl. All rights reserved.
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
7 * 1. Redistributions of source code must retain the above copyright
8 * notice, this list of conditions and the following disclaimer.
9 * 2. Redistributions in binary form must reproduce the above copyright
10 * notice, this list of conditions and the following disclaimer in the
11 * documentation and/or other materials provided with the distribution.
13 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
14 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
15 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
16 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
17 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
18 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
19 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
20 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
21 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
22 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26 RCSID("$OpenBSD: mac.c,v 1.6 2003/09/18 13:02:21 miod Exp $");
28 #include <openssl/hmac.h>
39 const EVP_MD * (*mdfunc)(void);
40 int truncatebits; /* truncate digest if != 0 */
42 { "hmac-sha1", EVP_sha1, 0, },
43 { "hmac-sha1-96", EVP_sha1, 96 },
44 { "hmac-md5", EVP_md5, 0 },
45 { "hmac-md5-96", EVP_md5, 96 },
46 { "hmac-ripemd160", EVP_ripemd160, 0 },
47 { "hmac-ripemd160@openssh.com", EVP_ripemd160, 0 },
52 mac_init(Mac *mac, char *name)
55 for (i = 0; macs[i].name; i++) {
56 if (strcmp(name, macs[i].name) == 0) {
58 mac->md = (*macs[i].mdfunc)();
59 mac->key_len = mac->mac_len = EVP_MD_size(mac->md);
60 if (macs[i].truncatebits != 0)
61 mac->mac_len = macs[i].truncatebits/8;
63 debug2("mac_init: found %s", name);
67 debug2("mac_init: unknown %s", name);
72 mac_compute(Mac *mac, u_int32_t seqno, u_char *data, int datalen)
75 static u_char m[EVP_MAX_MD_SIZE];
79 fatal("mac_compute: no key");
80 if ((u_int)mac->mac_len > sizeof(m))
81 fatal("mac_compute: mac too long");
82 HMAC_Init(&c, mac->key, mac->key_len, mac->md);
84 HMAC_Update(&c, b, sizeof(b));
85 HMAC_Update(&c, data, datalen);
86 HMAC_Final(&c, m, NULL);
91 /* XXX copied from ciphers_valid */
94 mac_valid(const char *names)
96 char *maclist, *cp, *p;
98 if (names == NULL || strcmp(names, "") == 0)
100 maclist = cp = xstrdup(names);
101 for ((p = strsep(&cp, MAC_SEP)); p && *p != '\0';
102 (p = strsep(&cp, MAC_SEP))) {
103 if (mac_init(NULL, p) < 0) {
104 debug("bad mac %s [%s]", p, names);
108 debug3("mac ok: %s [%s]", p, names);
111 debug3("macs ok: [%s]", names);