xref: /openbsd/lib/libradius/radius_eapmsk.c (revision 4cfece93)
1 /*	$OpenBSD: radius_eapmsk.c,v 1.1 2015/07/20 23:52:29 yasuoka Exp $ */
2 
3 /*-
4  * Copyright (c) 2013 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/md5.h>
39 
40 #include "radius.h"
41 
42 #include "radius_local.h"
43 
44 int
45 radius_get_eap_msk(const RADIUS_PACKET * packet, void *buf, size_t * len,
46     const char *secret)
47 {
48 	/*
49 	 * Unfortunately, the way to pass EAP MSK/EMSK over RADIUS
50 	 * is not standardized.
51 	 */
52 	uint8_t	 buf0[256];
53 	uint8_t	 buf1[256];
54 	size_t	 len0, len1;
55 
56 	/*
57 	 * EAP MSK via MPPE keys
58 	 *
59 	 * MSK = MPPE-Recv-Key + MPPE-Send-Key + 32byte zeros
60 	 * http://msdn.microsoft.com/en-us/library/cc224635.aspx
61 	 */
62 	len0 = sizeof(buf0);
63 	len1 = sizeof(buf1);
64 	if (radius_get_mppe_recv_key_attr(packet, buf0, &len0, secret) == 0 &&
65 	    radius_get_mppe_send_key_attr(packet, buf1, &len1, secret) == 0) {
66 		if (len0 < 16 || len1 < 16)
67 			return (-1);
68 		if (*len < 64)
69 			return (-1);
70 		memcpy(buf, buf0, 16);
71 		memcpy(((char *)buf) + 16, buf1, 16);
72 		memset(((char *)buf) + 32, 0, 32);
73 		*len = 64;
74 		return (0);
75 	}
76 
77 	return (-1);
78 }
79