radius_msgauth.c revision 1.1 
1/*	$OpenBSD: radius_msgauth.c,v 1.1 2015/07/20 23:52:29 yasuoka Exp $ */
2
3/*-
4 * Copyright (c) 2009 Internet Initiative Japan Inc.
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 *    notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 *    notice, this list of conditions and the following disclaimer in the
14 *    documentation and/or other materials provided with the distribution.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE"AUTHOR" AND CONTRIBUTORS AS IS'' AND
17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26 * SUCH DAMAGE.
27 */
28
29#include <sys/types.h>
30#include <sys/socket.h>
31#include <netinet/in.h>
32
33#include <stdbool.h>
34#include <stdio.h>
35#include <stdlib.h>
36#include <string.h>
37
38#include <openssl/hmac.h>
39
40#include "radius.h"
41
42#include "radius_local.h"
43
44static void
45radius_calc_message_authenticator(RADIUS_PACKET * packet, const char *secret,
46    void *ma)
47{
48	const RADIUS_ATTRIBUTE	*attr;
49	const RADIUS_ATTRIBUTE	*end;
50	u_char			 zero16[16];
51	HMAC_CTX		 ctx;
52	int			 mdlen;
53
54	memset(zero16, 0, sizeof(zero16));
55
56	HMAC_Init(&ctx, secret, strlen(secret), EVP_md5());
57
58	/*
59	 * Traverse the radius packet.
60	 */
61	if (packet->request != NULL) {
62		HMAC_Update(&ctx, (const u_char *)packet->pdata, 4);
63		HMAC_Update(&ctx, (unsigned char *)packet->request->pdata
64		    ->authenticator, 16);
65	} else {
66		HMAC_Update(&ctx, (const u_char *)packet->pdata,
67		    sizeof(RADIUS_PACKET_DATA));
68	}
69
70	attr = ATTRS_BEGIN(packet->pdata);
71	end = ATTRS_END(packet->pdata);
72
73	for (; attr < end; ATTRS_ADVANCE(attr)) {
74		if (attr->type == RADIUS_TYPE_MESSAGE_AUTHENTICATOR) {
75			HMAC_Update(&ctx, (u_char *)attr, 2);
76			HMAC_Update(&ctx, (u_char *)zero16, sizeof(zero16));
77		} else
78			HMAC_Update(&ctx, (u_char *)attr, (int) attr->length);
79	}
80
81	HMAC_Final(&ctx, (u_char *)ma, &mdlen);
82
83	HMAC_cleanup(&ctx);
84}
85
86int
87radius_put_message_authenticator(RADIUS_PACKET * packet, const char *secret)
88{
89	u_char	 ma[16];
90
91	/*
92	 * It is not required to initialize ma
93	 * because content of Message-Authenticator attribute is assumed zero
94	 * during calculation.
95	 */
96	if (radius_put_raw_attr(packet, RADIUS_TYPE_MESSAGE_AUTHENTICATOR,
97		ma, sizeof(ma)) != 0)
98		return (-1);
99
100	return (radius_set_message_authenticator(packet, secret));
101}
102
103int
104radius_set_message_authenticator(RADIUS_PACKET * packet, const char *secret)
105{
106	u_char	 ma[16];
107
108	radius_calc_message_authenticator(packet, secret, ma);
109
110	return (radius_set_raw_attr(packet, RADIUS_TYPE_MESSAGE_AUTHENTICATOR,
111	    ma, sizeof(ma)));
112}
113
114int
115radius_check_message_authenticator(RADIUS_PACKET * packet, const char *secret)
116{
117	int	 rval;
118	size_t	 len;
119	u_char	 ma0[16], ma1[16];
120
121	radius_calc_message_authenticator(packet, secret, ma0);
122
123	len = sizeof(ma1);
124	if ((rval = radius_get_raw_attr(packet,
125		    RADIUS_TYPE_MESSAGE_AUTHENTICATOR, ma1, &len)) != 0)
126		return (rval);
127
128	if (len != sizeof(ma1))
129		return (-1);
130
131	return (memcmp(ma0, ma1, sizeof(ma1)));
132}
133