aboutsummaryrefslogtreecommitdiff
path: root/sys/netipsec/xform_tcp.c
blob: a5edb15dcf2cfb1e56e076d5a059501de6ecbe40 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
/*	$FreeBSD$ */

/*-
 * Copyright (c) 2003 Bruce M. Simpson <bms@spc.org>
 *
 * 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.
 * 3. The name of the author may not be used to endorse or promote products
 *   derived from this software without specific prior written permission.
 *
 * 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.
 */

/* TCP MD5 Signature Option (RFC2385) */
#include "opt_inet.h"
#include "opt_inet6.h"

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/mbuf.h>
#include <sys/lock.h>
#include <sys/socket.h>
#include <sys/kernel.h>
#include <sys/protosw.h>
#include <sys/sysctl.h>

#include <netinet/in.h>
#include <netinet/in_systm.h>
#include <netinet/ip.h>
#include <netinet/ip_var.h>
#include <netinet/tcp.h>
#include <netinet/tcp_var.h>

#include <net/route.h>
#include <net/vnet.h>

#include <netipsec/ipsec.h>
#include <netipsec/xform.h>

#ifdef INET6
#include <netinet/ip6.h>
#include <netipsec/ipsec6.h>
#endif

#include <netipsec/key.h>
#include <netipsec/key_debug.h>

/*
 * Initialize a TCP-MD5 SA. Called when the SA is being set up.
 *
 * We don't need to set up the tdb prefixed fields, as we don't use the
 * opencrypto code; we just perform a key length check.
 *
 * XXX: Currently we only allow a single 'magic' SPI to be used.
 *
 * This allows per-host granularity without affecting the userland
 * interface, which is a simple socket option toggle switch,
 * TCP_SIGNATURE_ENABLE.
 *
 * To allow per-service granularity requires that we have a means
 * of mapping port to SPI. The mandated way of doing this is to
 * use SPD entries to specify packet flows which get the TCP-MD5
 * treatment, however the code to do this is currently unstable
 * and unsuitable for production use.
 *
 * Therefore we use this compromise in the meantime.
 */
static int
tcpsignature_init(struct secasvar *sav, struct xformsw *xsp)
{
	int keylen;

	if (sav->spi != htonl(TCP_SIG_SPI)) {
		DPRINTF(("%s: SPI must be TCP_SIG_SPI (0x1000)\n",
		    __func__));
		return (EINVAL);
	}
	if (sav->alg_auth != SADB_X_AALG_TCP_MD5) {
		DPRINTF(("%s: unsupported authentication algorithm %u\n",
		    __func__, sav->alg_auth));
		return (EINVAL);
	}
	if (sav->key_auth == NULL) {
		DPRINTF(("%s: no authentication key present\n", __func__));
		return (EINVAL);
	}
	keylen = _KEYLEN(sav->key_auth);
	if ((keylen < TCP_KEYLEN_MIN) || (keylen > TCP_KEYLEN_MAX)) {
		DPRINTF(("%s: invalid key length %u\n", __func__, keylen));
		return (EINVAL);
	}

	return (0);
}

/*
 * Paranoia.
 *
 * Called when the SA is deleted.
 */
static int
tcpsignature_zeroize(struct secasvar *sav)
{

	if (sav->key_auth)
		bzero(sav->key_auth->key_data, _KEYLEN(sav->key_auth));

	sav->tdb_cryptoid = 0;
	sav->tdb_authalgxform = NULL;
	sav->tdb_xform = NULL;

	return (0);
}

/*
 * Verify that an input packet passes authentication.
 * Called from the ipsec layer.
 * We do this from within tcp itself, so this routine is just a stub.
 */
static int
tcpsignature_input(struct mbuf *m, struct secasvar *sav, int skip,
    int protoff)
{

	return (0);
}

/*
 * Prepend the authentication header.
 * Called from the ipsec layer.
 * We do this from within tcp itself, so this routine is just a stub.
 */
static int
tcpsignature_output(struct mbuf *m, struct ipsecrequest *isr,
    struct mbuf **mp, int skip, int protoff)
{

	return (EINVAL);
}

static struct xformsw tcpsignature_xformsw = {
	XF_TCPSIGNATURE,	XFT_AUTH,		"TCPMD5",
	tcpsignature_init,	tcpsignature_zeroize,
	tcpsignature_input,	tcpsignature_output
};

static void
tcpsignature_attach(void)
{

	xform_register(&tcpsignature_xformsw);
}

SYSINIT(tcpsignature_xform_init, SI_SUB_DRIVERS, SI_ORDER_FIRST,
    tcpsignature_attach, NULL);