1 /* $NetBSD: xform_tcp.c,v 1.21 2018/05/14 02:16:29 ozaki-r Exp $ */ 2 /* $FreeBSD: 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 /* 32 * TCP MD5 Signature Option (RFC2385). Dummy code, everything is handled 33 * in TCP directly. 34 */ 35 36 #include <sys/cdefs.h> 37 __KERNEL_RCSID(0, "$NetBSD: xform_tcp.c,v 1.21 2018/05/14 02:16:29 ozaki-r Exp $"); 38 39 #if defined(_KERNEL_OPT) 40 #include "opt_inet.h" 41 #endif 42 43 #include <sys/param.h> 44 #include <sys/systm.h> 45 #include <sys/mbuf.h> 46 #include <sys/kernel.h> 47 48 #include <netinet/in.h> 49 #include <netinet/in_systm.h> 50 #include <netinet/ip.h> 51 #include <netinet/ip_var.h> 52 #ifdef TCP_SIGNATURE 53 #include <netinet/tcp_timer.h> 54 #include <netinet/tcp.h> 55 #include <netinet/tcp_var.h> 56 #endif 57 58 #include <netipsec/ipsec.h> 59 #include <netipsec/xform.h> 60 61 #include <netipsec/key.h> 62 #include <netipsec/key_debug.h> 63 64 /* 65 * Initialize a TCP-MD5 SA. Called when the SA is being set up. 66 * 67 * We don't need to set up the tdb prefixed fields, as we don't use the 68 * opencrypto code; we just perform a key length check. 69 * 70 * XXX: Currently we only allow a single 'magic' SPI to be used. 71 * 72 * This allows per-host granularity without affecting the userland 73 * interface, which is a simple socket option toggle switch, 74 * TCP_SIGNATURE_ENABLE. 75 * 76 * To allow per-service granularity requires that we have a means 77 * of mapping port to SPI. The mandated way of doing this is to 78 * use SPD entries to specify packet flows which get the TCP-MD5 79 * treatment, however the code to do this is currently unstable 80 * and unsuitable for production use. 81 * 82 * Therefore we use this compromise in the meantime. 83 */ 84 static int 85 tcpsignature_init(struct secasvar *sav, const struct xformsw *xsp) 86 { 87 int keylen; 88 89 if (sav->spi != htonl(TCP_SIG_SPI)) { 90 DPRINTF(("%s: SPI %x must be TCP_SIG_SPI (0x1000)\n", 91 __func__, sav->alg_auth)); 92 return EINVAL; 93 } 94 if (sav->alg_auth != SADB_X_AALG_TCP_MD5) { 95 DPRINTF(("%s: unsupported authentication algorithm %u\n", 96 __func__, sav->alg_auth)); 97 return EINVAL; 98 } 99 if (sav->key_auth == NULL) { 100 DPRINTF(("%s: no authentication key present\n", __func__)); 101 return EINVAL; 102 } 103 keylen = _KEYLEN(sav->key_auth); 104 if ((keylen < TCP_KEYLEN_MIN) || (keylen > TCP_KEYLEN_MAX)) { 105 DPRINTF(("%s: invalid key length %u\n", __func__, keylen)); 106 return EINVAL; 107 } 108 109 return 0; 110 } 111 112 static int 113 tcpsignature_zeroize(struct secasvar *sav) 114 { 115 if (sav->key_auth) { 116 explicit_memset(_KEYBUF(sav->key_auth), 0, 117 _KEYLEN(sav->key_auth)); 118 } 119 120 sav->tdb_cryptoid = 0; 121 sav->tdb_authalgxform = NULL; 122 sav->tdb_xform = NULL; 123 124 return 0; 125 } 126 127 static int 128 tcpsignature_input(struct mbuf *m, struct secasvar *sav, int skip, 129 int protoff) 130 { 131 panic("%s: should not have been called", __func__); 132 } 133 134 static int 135 tcpsignature_output(struct mbuf *m, const struct ipsecrequest *isr, 136 struct secasvar *sav, int skip, int protoff) 137 { 138 panic("%s: should not have been called", __func__); 139 } 140 141 static struct xformsw tcpsignature_xformsw = { 142 .xf_type = XF_TCPSIGNATURE, 143 .xf_flags = XFT_AUTH, 144 .xf_name = "TCPMD5", 145 .xf_init = tcpsignature_init, 146 .xf_zeroize = tcpsignature_zeroize, 147 .xf_input = tcpsignature_input, 148 .xf_output = tcpsignature_output, 149 .xf_next = NULL, 150 }; 151 152 void 153 tcpsignature_attach(void) 154 { 155 xform_register(&tcpsignature_xformsw); 156 } 157