xref: /openbsd/lib/libradius/radius_eapmsk.c (revision e1d9e6fd)
1 /*	$OpenBSD: radius_eapmsk.c,v 1.3 2024/02/09 11:59:23 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 <stdint.h>
30 #include <string.h>
31 
32 #include "radius.h"
33 
34 #include "radius_local.h"
35 
36 int
radius_get_eap_msk(const RADIUS_PACKET * packet,void * buf,size_t * len,const char * secret)37 radius_get_eap_msk(const RADIUS_PACKET * packet, void *buf, size_t *len,
38     const char *secret)
39 {
40 	uint8_t	 buf0[256];
41 	uint8_t	 buf1[256];
42 	size_t	 len0, len1, msklen;
43 
44 	/* RFC 3748 defines the MSK minimum size is 64 bytes */
45 	if (*len < 64)
46 		return (-1);
47 	len0 = sizeof(buf0);
48 	len1 = sizeof(buf1);
49 	if (radius_get_mppe_recv_key_attr(packet, buf0, &len0, secret) == 0 &&
50 	    radius_get_mppe_send_key_attr(packet, buf1, &len1, secret) == 0) {
51 		/* addition cannot overflow since len{0,1} are limited to 256 */
52 		msklen = len0 + len1;
53 		if (msklen > *len)
54 			return (-1);	/* not enougth */
55 		memcpy(buf, buf0, len0);
56 		memcpy(((char *)buf) + len0, buf1, len1);
57 		/* zero padding to the minimum size, 64 bytes.  */
58 		if (msklen < 64) {
59 			memset(((char *)buf) + msklen, 0, 64 - msklen);
60 			msklen = 64;
61 		}
62 		*len = msklen;
63 		return (0);
64 	}
65 
66 	return (-1);
67 }
68