1 /* $NetBSD: xform_tcp.c,v 1.2 2005/02/26 22:45:13 perry Exp $ */
2 /* $FreeBSD: sys/netipsec/xform_tcp.c,v 1.1.2.1 2004/02/14 22:24:09 bms Exp $ */
3
4 /*
5 * Copyright (c) 2003 Bruce M. Simpson <bms@spc.org>
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 *
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 * 3. The name of the author may not be used to endorse or promote products
17 * derived from this software without specific prior written permission.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
20 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
21 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
22 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
23 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
24 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
25 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
26 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
27 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
28 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
29 */
30
31 /* TCP MD5 Signature Option (RFC2385) */
32 #include "opt_inet.h"
33
34 #include <sys/param.h>
35 #include <sys/systm.h>
36 #include <sys/mbuf.h>
37 #include <sys/lock.h>
38 #include <sys/socket.h>
39 #include <sys/kernel.h>
40 #include <sys/protosw.h>
41 #include <sys/sysctl.h>
42
43 #include <netinet/in.h>
44 #include <netinet/in_systm.h>
45 #include <netinet/ip.h>
46 #include <netinet/ip_var.h>
47 #include <netinet/tcp_timer.h>
48 #include <netinet/tcp.h>
49 #include <netinet/tcp_var.h>
50
51 #include <net/route.h>
52 #include <netipsec/ipsec.h>
53 #include <netipsec/xform.h>
54
55 #ifdef INET6
56 #include <netinet/ip6.h>
57 #include <netipsec/ipsec6.h>
58 #endif
59
60 #include <netipsec/key.h>
61 #include <netipsec/key_debug.h>
62
63 /*
64 * Initialize a TCP-MD5 SA. Called when the SA is being set up.
65 *
66 * We don't need to set up the tdb prefixed fields, as we don't use the
67 * opencrypto code; we just perform a key length check.
68 *
69 * XXX: Currently we only allow a single 'magic' SPI to be used.
70 *
71 * This allows per-host granularity without affecting the userland
72 * interface, which is a simple socket option toggle switch,
73 * TCP_SIGNATURE_ENABLE.
74 *
75 * To allow per-service granularity requires that we have a means
76 * of mapping port to SPI. The mandated way of doing this is to
77 * use SPD entries to specify packet flows which get the TCP-MD5
78 * treatment, however the code to do this is currently unstable
79 * and unsuitable for production use.
80 *
81 * Therefore we use this compromise in the meantime.
82 */
83 static int
84 tcpsignature_init(struct secasvar *sav, struct xformsw *xsp)
85 {
86 int keylen;
87
88 if (sav->spi != htonl(TCP_SIG_SPI)) {
89 DPRINTF(("%s: SPI %x must be TCP_SIG_SPI (0x1000)\n",
90 __func__, sav->alg_auth));
91 return (EINVAL);
92 }
93 if (sav->alg_auth != SADB_X_AALG_TCP_MD5) {
94 DPRINTF(("%s: unsupported authentication algorithm %u\n",
95 __func__, sav->alg_auth));
96 return (EINVAL);
97 }
98 if (sav->key_auth == NULL) {
99 DPRINTF(("%s: no authentication key present\n", __func__));
100 return (EINVAL);
101 }
102 keylen = _KEYLEN(sav->key_auth);
103 if ((keylen < TCP_KEYLEN_MIN) || (keylen > TCP_KEYLEN_MAX)) {
104 DPRINTF(("%s: invalid key length %u\n", __func__, keylen));
105 return (EINVAL);
106 }
107
108 return (0);
109 }
110
111 /*
112 * Paranoia.
113 *
114 * Called when the SA is deleted.
115 */
116 static int
117 tcpsignature_zeroize(struct secasvar *sav)
118 {
119
120 if (sav->key_auth)
121 bzero(_KEYBUF(sav->key_auth), _KEYLEN(sav->key_auth));
122
123 sav->tdb_cryptoid = 0;
124 sav->tdb_authalgxform = NULL;
125 sav->tdb_xform = NULL;
126
127 return (0);
128 }
129
130 /*
131 * Verify that an input packet passes authentication.
132 * Called from the ipsec layer.
133 * We do this from within tcp itself, so this routine is just a stub.
134 */
135 static int
136 tcpsignature_input(struct mbuf *m, struct secasvar *sav, int skip,
137 int protoff)
138 {
139
140 return (0);
141 }
142
143 /*
144 * Prepend the authentication header.
145 * Called from the ipsec layer.
146 * We do this from within tcp itself, so this routine is just a stub.
147 */
148 static int
149 tcpsignature_output(struct mbuf *m, struct ipsecrequest *isr,
150 struct mbuf **mp, int skip, int protoff)
151 {
152
153 return (EINVAL);
154 }
155
156 static struct xformsw tcpsignature_xformsw = {
157 XF_TCPSIGNATURE, XFT_AUTH, "TCPMD5",
158 tcpsignature_init, tcpsignature_zeroize,
159 tcpsignature_input, tcpsignature_output
160 };
161
162 INITFN void
163 tcpsignature_attach(void)
164 {
165
166 xform_register(&tcpsignature_xformsw);
167 }
168
169 #ifdef __FreeBSD__
170 SYSINIT(tcpsignature_xform_init, SI_SUB_DRIVERS, SI_ORDER_FIRST,
171 tcpsignature_attach, NULL)
172
173 #endif
174
Cache object: 768a25fcd2b8a98ea46d1501b2e15d25
|