[gssapi-openssh.git] / openssh / mac.c

/*
 * Copyright (c) 2001 Markus Friedl.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#include "includes.h"
RCSID("$OpenBSD: mac.c,v 1.2 2001/04/05 10:42:51 markus Exp $");

#include <openssl/hmac.h>

#include "xmalloc.h"
#include "getput.h"
#include "log.h"
#include "cipher.h"
#include "kex.h"
#include "mac.h"

struct {
	char		*name;
	EVP_MD *	(*mdfunc)(void);
	int		truncatebits;	/* truncate digest if != 0 */
} macs[] = {
	{ "hmac-sha1",			EVP_sha1, 0, },
	{ "hmac-sha1-96",		EVP_sha1, 96 },
	{ "hmac-md5",			EVP_md5, 0 },
	{ "hmac-md5-96",		EVP_md5, 96 },
	{ "hmac-ripemd160",		EVP_ripemd160, 0 },
	{ "hmac-ripemd160@openssh.com",	EVP_ripemd160, 0 },
	{ NULL,				NULL, 0 }
};

int
mac_init(Mac *mac, char *name)
{
	int i;
	for (i = 0; macs[i].name; i++) {
		if (strcmp(name, macs[i].name) == 0) {
			if (mac != NULL) {
				mac->md = (*macs[i].mdfunc)();
				mac->key_len = mac->mac_len = mac->md->md_size;
				if (macs[i].truncatebits != 0)
					mac->mac_len = macs[i].truncatebits/8;
			}
			debug2("mac_init: found %s", name);
			return (0);
		}
	}
	debug2("mac_init: unknown %s", name);
	return (-1);
}

u_char *
mac_compute(Mac *mac, u_int32_t seqno, u_char *data, int datalen)
{
	HMAC_CTX c;
	static u_char m[EVP_MAX_MD_SIZE];
	u_char b[4];

	if (mac->key == NULL)
		fatal("mac_compute: no key");
	if (mac->mac_len > sizeof(m))
		fatal("mac_compute: mac too long");
	HMAC_Init(&c, mac->key, mac->key_len, mac->md);
	PUT_32BIT(b, seqno);
	HMAC_Update(&c, b, sizeof(b));
	HMAC_Update(&c, data, datalen);
	HMAC_Final(&c, m, NULL);
	HMAC_cleanup(&c);
	return (m);
}

/* XXX copied from ciphers_valid */
#define	MAC_SEP	","
int
mac_valid(const char *names)
{
	char *maclist, *cp, *p;

	if (names == NULL || strcmp(names, "") == 0)
		return (0);
	maclist = cp = xstrdup(names);
	for ((p = strsep(&cp, MAC_SEP)); p && *p != '\0';
	     (p = strsep(&cp, MAC_SEP))) {
		if (mac_init(NULL, p) < 0) {
			debug("bad mac %s [%s]", p, names);
			xfree(maclist);
			return (0);
		} else {
			debug3("mac ok: %s [%s]", p, names);
		}
	}
	debug3("macs ok: [%s]", names);
	xfree(maclist);
	return (1);
}
Commit	Line	Data
3c0ef626	1	/*
	2	* Copyright (c) 2001 Markus Friedl. All rights reserved.
	3	*
	4	* Redistribution and use in source and binary forms, with or without
	5	* modification, are permitted provided that the following conditions
	6	* are met:
	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.
	12	*
	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.
	23	*/
	24
	25	#include "includes.h"
	26	RCSID("$OpenBSD: mac.c,v 1.2 2001/04/05 10:42:51 markus Exp $");
	27
	28	#include <openssl/hmac.h>
	29
	30	#include "xmalloc.h"
	31	#include "getput.h"
	32	#include "log.h"
	33	#include "cipher.h"
	34	#include "kex.h"
	35	#include "mac.h"
	36
	37	struct {
	38	char *name;
	39	EVP_MD * (*mdfunc)(void);
	40	int truncatebits; /* truncate digest if != 0 */
	41	} macs[] = {
	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 },
	48	{ NULL, NULL, 0 }
	49	};
	50
	51	int
	52	mac_init(Mac mac, char name)
	53	{
	54	int i;
	55	for (i = 0; macs[i].name; i++) {
	56	if (strcmp(name, macs[i].name) == 0) {
	57	if (mac != NULL) {
	58	mac->md = (*macs[i].mdfunc)();
	59	mac->key_len = mac->mac_len = mac->md->md_size;
	60	if (macs[i].truncatebits != 0)
	61	mac->mac_len = macs[i].truncatebits/8;
	62	}
	63	debug2("mac_init: found %s", name);
	64	return (0);
65	}
66	}
67	debug2("mac_init: unknown %s", name);
68	return (-1);
69	}
70
71	u_char *
72	mac_compute(Mac mac, u_int32_t seqno, u_char data, int datalen)
73	{
74	HMAC_CTX c;
75	static u_char m[EVP_MAX_MD_SIZE];
76	u_char b[4];
77
78	if (mac->key == NULL)
79	fatal("mac_compute: no key");
80	if (mac->mac_len > sizeof(m))
81	fatal("mac_compute: mac too long");
82	HMAC_Init(&c, mac->key, mac->key_len, mac->md);
83	PUT_32BIT(b, seqno);
84	HMAC_Update(&c, b, sizeof(b));
85	HMAC_Update(&c, data, datalen);
86	HMAC_Final(&c, m, NULL);
87	HMAC_cleanup(&c);
88	return (m);
89	}
90
91	/* XXX copied from ciphers_valid */
92	#define MAC_SEP ","
93	int
94	mac_valid(const char *names)
95	{
96	char maclist, cp, *p;
97
98	if (names == NULL \|\| strcmp(names, "") == 0)
99	return (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);
105	xfree(maclist);
106	return (0);
107	} else {
108	debug3("mac ok: %s [%s]", p, names);
109	}
110	}
111	debug3("macs ok: [%s]", names);
112	xfree(maclist);
113	return (1);
114	}