NetBSD/sys/netipsec/xform_tcp.c

156 lines
4.6 KiB
C

/* $NetBSD: xform_tcp.c,v 1.24 2019/11/01 04:23:21 knakahara Exp $ */
/* $FreeBSD: xform_tcp.c,v 1.1.2.1 2004/02/14 22:24:09 bms Exp $ */
/*
* 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). Dummy code, everything is handled
* in TCP directly.
*/
#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: xform_tcp.c,v 1.24 2019/11/01 04:23:21 knakahara Exp $");
#if defined(_KERNEL_OPT)
#include "opt_inet.h"
#endif
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/mbuf.h>
#include <sys/kernel.h>
#include <netinet/in.h>
#include <netinet/in_systm.h>
#include <netinet/ip.h>
#include <netinet/ip_var.h>
#ifdef TCP_SIGNATURE
#include <netinet/tcp_timer.h>
#include <netinet/tcp.h>
#include <netinet/tcp_var.h>
#endif
#include <netipsec/ipsec.h>
#include <netipsec/xform.h>
#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, const struct xformsw *xsp)
{
int keylen;
if (sav->spi != htonl(TCP_SIG_SPI)) {
DPRINTF("SPI %x must be TCP_SIG_SPI (0x1000)\n", sav->alg_auth);
return EINVAL;
}
if (sav->alg_auth != SADB_X_AALG_TCP_MD5) {
DPRINTF("unsupported authentication algorithm %u\n",
sav->alg_auth);
return EINVAL;
}
if (sav->key_auth == NULL) {
DPRINTF("no authentication key present\n");
return EINVAL;
}
keylen = _KEYLEN(sav->key_auth);
if ((keylen < TCP_KEYLEN_MIN) || (keylen > TCP_KEYLEN_MAX)) {
DPRINTF("invalid key length %u\n", keylen);
return EINVAL;
}
return 0;
}
static int
tcpsignature_zeroize(struct secasvar *sav)
{
if (sav->key_auth) {
explicit_memset(_KEYBUF(sav->key_auth), 0,
_KEYLEN(sav->key_auth));
}
sav->tdb_cryptoid = 0;
sav->tdb_authalgxform = NULL;
sav->tdb_xform = NULL;
return 0;
}
static int
tcpsignature_input(struct mbuf *m, struct secasvar *sav, int skip,
int protoff)
{
panic("%s: should not have been called", __func__);
}
static int
tcpsignature_output(struct mbuf *m, const struct ipsecrequest *isr,
struct secasvar *sav, int skip, int protoff, int flags)
{
panic("%s: should not have been called", __func__);
}
static struct xformsw tcpsignature_xformsw = {
.xf_type = XF_TCPSIGNATURE,
.xf_flags = XFT_AUTH,
.xf_name = "TCPMD5",
.xf_init = tcpsignature_init,
.xf_zeroize = tcpsignature_zeroize,
.xf_input = tcpsignature_input,
.xf_output = tcpsignature_output,
.xf_next = NULL,
};
void
tcpsignature_attach(void)
{
xform_register(&tcpsignature_xformsw);
}