1052 lines
27 KiB
C
1052 lines
27 KiB
C
/* $NetBSD: xform_esp.c,v 1.18 2008/04/23 06:09:05 thorpej Exp $ */
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/* $FreeBSD: src/sys/netipsec/xform_esp.c,v 1.2.2.1 2003/01/24 05:11:36 sam Exp $ */
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/* $OpenBSD: ip_esp.c,v 1.69 2001/06/26 06:18:59 angelos Exp $ */
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/*
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* The authors of this code are John Ioannidis (ji@tla.org),
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* Angelos D. Keromytis (kermit@csd.uch.gr) and
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* Niels Provos (provos@physnet.uni-hamburg.de).
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*
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* The original version of this code was written by John Ioannidis
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* for BSD/OS in Athens, Greece, in November 1995.
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*
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* Ported to OpenBSD and NetBSD, with additional transforms, in December 1996,
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* by Angelos D. Keromytis.
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*
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* Additional transforms and features in 1997 and 1998 by Angelos D. Keromytis
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* and Niels Provos.
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*
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* Additional features in 1999 by Angelos D. Keromytis.
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*
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* Copyright (C) 1995, 1996, 1997, 1998, 1999 by John Ioannidis,
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* Angelos D. Keromytis and Niels Provos.
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* Copyright (c) 2001 Angelos D. Keromytis.
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*
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* Permission to use, copy, and modify this software with or without fee
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* is hereby granted, provided that this entire notice is included in
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* all copies of any software which is or includes a copy or
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* modification of this software.
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* You may use this code under the GNU public license if you so wish. Please
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* contribute changes back to the authors under this freer than GPL license
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* so that we may further the use of strong encryption without limitations to
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* all.
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*
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* THIS SOFTWARE IS BEING PROVIDED "AS IS", WITHOUT ANY EXPRESS OR
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* IMPLIED WARRANTY. IN PARTICULAR, NONE OF THE AUTHORS MAKES ANY
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* REPRESENTATION OR WARRANTY OF ANY KIND CONCERNING THE
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* MERCHANTABILITY OF THIS SOFTWARE OR ITS FITNESS FOR ANY PARTICULAR
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* PURPOSE.
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*/
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#include <sys/cdefs.h>
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__KERNEL_RCSID(0, "$NetBSD: xform_esp.c,v 1.18 2008/04/23 06:09:05 thorpej Exp $");
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#include "opt_inet.h"
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#ifdef __FreeBSD__
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#include "opt_inet6.h"
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#endif
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#include <sys/param.h>
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#include <sys/systm.h>
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#include <sys/mbuf.h>
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#include <sys/socket.h>
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#include <sys/syslog.h>
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#include <sys/kernel.h>
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/*#include <sys/random.h>*/
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#include <sys/sysctl.h>
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#include <net/if.h>
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#include <netinet/in.h>
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#include <netinet/in_systm.h>
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#include <netinet/ip.h>
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#include <netinet/ip_ecn.h>
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#include <netinet/ip6.h>
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#include <net/route.h>
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#include <netipsec/ipsec.h>
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#include <netipsec/ipsec_private.h>
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#include <netipsec/ah.h>
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#include <netipsec/ah_var.h>
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#include <netipsec/esp.h>
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#include <netipsec/esp_var.h>
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#include <netipsec/xform.h>
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#ifdef INET6
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#include <netinet6/ip6_var.h>
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#include <netipsec/ipsec6.h>
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# ifdef __FreeBSD__
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# include <netinet6/ip6_ecn.h>
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# endif
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#endif
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#include <netipsec/key.h>
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#include <netipsec/key_debug.h>
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#include <netipsec/ipsec_osdep.h>
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#include <opencrypto/cryptodev.h>
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#include <opencrypto/xform.h>
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percpu_t *espstat_percpu;
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int esp_enable = 1;
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#ifdef __FreeBSD__
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SYSCTL_DECL(_net_inet_esp);
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SYSCTL_INT(_net_inet_esp, OID_AUTO,
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esp_enable, CTLFLAG_RW, &esp_enable, 0, "");
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SYSCTL_STRUCT(_net_inet_esp, IPSECCTL_STATS,
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stats, CTLFLAG_RD, &espstat, espstat, "");
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#endif /* __FreeBSD__ */
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static int esp_max_ivlen; /* max iv length over all algorithms */
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static int esp_input_cb(struct cryptop *op);
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static int esp_output_cb(struct cryptop *crp);
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/*
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* NB: this is public for use by the PF_KEY support.
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* NB: if you add support here; be sure to add code to esp_attach below!
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*/
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struct enc_xform *
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esp_algorithm_lookup(int alg)
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{
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if (alg >= ESP_ALG_MAX)
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return NULL;
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switch (alg) {
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case SADB_EALG_DESCBC:
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return &enc_xform_des;
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case SADB_EALG_3DESCBC:
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return &enc_xform_3des;
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case SADB_X_EALG_AES:
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return &enc_xform_rijndael128;
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case SADB_X_EALG_BLOWFISHCBC:
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return &enc_xform_blf;
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case SADB_X_EALG_CAST128CBC:
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return &enc_xform_cast5;
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case SADB_X_EALG_SKIPJACK:
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return &enc_xform_skipjack;
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case SADB_EALG_NULL:
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return &enc_xform_null;
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}
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return NULL;
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}
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size_t
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esp_hdrsiz(struct secasvar *sav)
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{
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size_t size;
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if (sav != NULL) {
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/*XXX not right for null algorithm--does it matter??*/
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IPSEC_ASSERT(sav->tdb_encalgxform != NULL,
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("esp_hdrsiz: SA with null xform"));
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if (sav->flags & SADB_X_EXT_OLD)
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size = sizeof (struct esp);
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else
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size = sizeof (struct newesp);
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size += sav->tdb_encalgxform->blocksize + 9;
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/*XXX need alg check???*/
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if (sav->tdb_authalgxform != NULL && sav->replay)
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size += ah_hdrsiz(sav);
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} else {
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/*
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* base header size
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* + max iv length for CBC mode
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* + max pad length
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* + sizeof (pad length field)
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* + sizeof (next header field)
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* + max icv supported.
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*/
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size = sizeof (struct newesp) + esp_max_ivlen + 9 + 16;
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}
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return size;
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}
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/*
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* esp_init() is called when an SPI is being set up.
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*/
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static int
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esp_init(struct secasvar *sav, struct xformsw *xsp)
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{
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struct enc_xform *txform;
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struct cryptoini cria, crie;
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int keylen;
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int error;
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txform = esp_algorithm_lookup(sav->alg_enc);
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if (txform == NULL) {
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DPRINTF(("esp_init: unsupported encryption algorithm %d\n",
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sav->alg_enc));
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return EINVAL;
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}
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if (sav->key_enc == NULL) {
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DPRINTF(("esp_init: no encoding key for %s algorithm\n",
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txform->name));
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return EINVAL;
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}
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if ((sav->flags&(SADB_X_EXT_OLD|SADB_X_EXT_IV4B)) == SADB_X_EXT_IV4B) {
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DPRINTF(("esp_init: 4-byte IV not supported with protocol\n"));
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return EINVAL;
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}
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keylen = _KEYLEN(sav->key_enc);
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if (txform->minkey > keylen || keylen > txform->maxkey) {
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DPRINTF(("esp_init: invalid key length %u, must be in "
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"the range [%u..%u] for algorithm %s\n",
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keylen, txform->minkey, txform->maxkey,
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txform->name));
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return EINVAL;
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}
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/*
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* NB: The null xform needs a non-zero blocksize to keep the
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* crypto code happy but if we use it to set ivlen then
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* the ESP header will be processed incorrectly. The
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* compromise is to force it to zero here.
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*/
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sav->ivlen = (txform == &enc_xform_null ? 0 : txform->blocksize);
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sav->iv = malloc(sav->ivlen, M_SECA, M_WAITOK);
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if (sav->iv == NULL) {
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DPRINTF(("esp_init: no memory for IV\n"));
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return EINVAL;
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}
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key_randomfill(sav->iv, sav->ivlen); /*XXX*/
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/*
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* Setup AH-related state.
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*/
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if (sav->alg_auth != 0) {
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error = ah_init0(sav, xsp, &cria);
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if (error)
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return error;
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}
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/* NB: override anything set in ah_init0 */
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sav->tdb_xform = xsp;
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sav->tdb_encalgxform = txform;
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/* Initialize crypto session. */
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bzero(&crie, sizeof (crie));
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crie.cri_alg = sav->tdb_encalgxform->type;
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crie.cri_klen = _KEYBITS(sav->key_enc);
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crie.cri_key = _KEYBUF(sav->key_enc);
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/* XXX Rounds ? */
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mutex_spin_enter(&crypto_mtx);
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if (sav->tdb_authalgxform && sav->tdb_encalgxform) {
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/* init both auth & enc */
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crie.cri_next = &cria;
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error = crypto_newsession(&sav->tdb_cryptoid,
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&crie, crypto_support);
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} else if (sav->tdb_encalgxform) {
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error = crypto_newsession(&sav->tdb_cryptoid,
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&crie, crypto_support);
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} else if (sav->tdb_authalgxform) {
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error = crypto_newsession(&sav->tdb_cryptoid,
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&cria, crypto_support);
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} else {
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/* XXX cannot happen? */
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DPRINTF(("esp_init: no encoding OR authentication xform!\n"));
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error = EINVAL;
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}
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mutex_spin_exit(&crypto_mtx);
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return error;
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}
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/*
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* Paranoia.
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*/
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static int
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esp_zeroize(struct secasvar *sav)
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{
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/* NB: ah_zerorize free's the crypto session state */
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int error = ah_zeroize(sav);
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if (sav->key_enc)
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bzero(_KEYBUF(sav->key_enc), _KEYLEN(sav->key_enc));
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/* NB: sav->iv is freed elsewhere, even though we malloc it! */
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sav->tdb_encalgxform = NULL;
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sav->tdb_xform = NULL;
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return error;
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}
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/*
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* ESP input processing, called (eventually) through the protocol switch.
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*/
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static int
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esp_input(struct mbuf *m, struct secasvar *sav, int skip, int protoff)
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{
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struct auth_hash *esph;
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struct enc_xform *espx;
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struct tdb_ident *tdbi;
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struct tdb_crypto *tc;
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int plen, alen, hlen;
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struct m_tag *mtag;
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struct newesp *esp;
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struct cryptodesc *crde;
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struct cryptop *crp;
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IPSEC_SPLASSERT_SOFTNET("esp_input");
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IPSEC_ASSERT(sav != NULL, ("esp_input: null SA"));
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IPSEC_ASSERT(sav->tdb_encalgxform != NULL,
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("esp_input: null encoding xform"));
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IPSEC_ASSERT((skip&3) == 0 && (m->m_pkthdr.len&3) == 0,
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("esp_input: misaligned packet, skip %u pkt len %u",
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skip, m->m_pkthdr.len));
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/* XXX don't pullup, just copy header */
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IP6_EXTHDR_GET(esp, struct newesp *, m, skip, sizeof (struct newesp));
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esph = sav->tdb_authalgxform;
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espx = sav->tdb_encalgxform;
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/* Determine the ESP header length */
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if (sav->flags & SADB_X_EXT_OLD)
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hlen = sizeof (struct esp) + sav->ivlen;
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else
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hlen = sizeof (struct newesp) + sav->ivlen;
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/* Authenticator hash size */
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alen = esph ? AH_HMAC_HASHLEN : 0;
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/*
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* Verify payload length is multiple of encryption algorithm
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* block size.
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*
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* NB: This works for the null algorithm because the blocksize
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* is 4 and all packets must be 4-byte aligned regardless
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* of the algorithm.
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*/
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plen = m->m_pkthdr.len - (skip + hlen + alen);
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if ((plen & (espx->blocksize - 1)) || (plen <= 0)) {
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DPRINTF(("esp_input: "
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"payload of %d octets not a multiple of %d octets,"
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" SA %s/%08lx\n",
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plen, espx->blocksize,
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ipsec_address(&sav->sah->saidx.dst),
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(u_long) ntohl(sav->spi)));
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ESP_STATINC(ESP_STAT_BADILEN);
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m_freem(m);
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return EINVAL;
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}
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/*
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* Check sequence number.
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*/
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if (esph && sav->replay && !ipsec_chkreplay(ntohl(esp->esp_seq), sav)) {
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DPRINTF(("esp_input: packet replay check for %s\n",
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ipsec_logsastr(sav))); /*XXX*/
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ESP_STATINC(ESP_STAT_REPLAY);
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m_freem(m);
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return ENOBUFS; /*XXX*/
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}
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/* Update the counters */
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ESP_STATADD(ESP_STAT_IBYTES, m->m_pkthdr.len - skip - hlen - alen);
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/* Find out if we've already done crypto */
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for (mtag = m_tag_find(m, PACKET_TAG_IPSEC_IN_CRYPTO_DONE, NULL);
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mtag != NULL;
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mtag = m_tag_find(m, PACKET_TAG_IPSEC_IN_CRYPTO_DONE, mtag)) {
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tdbi = (struct tdb_ident *) (mtag + 1);
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if (tdbi->proto == sav->sah->saidx.proto &&
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tdbi->spi == sav->spi &&
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!bcmp(&tdbi->dst, &sav->sah->saidx.dst,
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sizeof(union sockaddr_union)))
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break;
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}
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/* Get crypto descriptors */
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crp = crypto_getreq(esph && espx ? 2 : 1);
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if (crp == NULL) {
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DPRINTF(("esp_input: failed to acquire crypto descriptors\n"));
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ESP_STATINC(ESP_STAT_CRYPTO);
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m_freem(m);
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return ENOBUFS;
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}
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/* Get IPsec-specific opaque pointer */
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if (esph == NULL || mtag != NULL)
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tc = (struct tdb_crypto *) malloc(sizeof(struct tdb_crypto),
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M_XDATA, M_NOWAIT|M_ZERO);
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else
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tc = (struct tdb_crypto *) malloc(sizeof(struct tdb_crypto) + alen,
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M_XDATA, M_NOWAIT|M_ZERO);
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if (tc == NULL) {
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crypto_freereq(crp);
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DPRINTF(("esp_input: failed to allocate tdb_crypto\n"));
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ESP_STATINC(ESP_STAT_CRYPTO);
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m_freem(m);
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return ENOBUFS;
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}
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tc->tc_ptr = mtag;
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if (esph) {
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struct cryptodesc *crda = crp->crp_desc;
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IPSEC_ASSERT(crda != NULL, ("esp_input: null ah crypto descriptor"));
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/* Authentication descriptor */
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crda->crd_skip = skip;
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crda->crd_len = m->m_pkthdr.len - (skip + alen);
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crda->crd_inject = m->m_pkthdr.len - alen;
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crda->crd_alg = esph->type;
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crda->crd_key = _KEYBUF(sav->key_auth);
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crda->crd_klen = _KEYBITS(sav->key_auth);
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/* Copy the authenticator */
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if (mtag == NULL)
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m_copydata(m, m->m_pkthdr.len - alen, alen,
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(tc + 1));
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/* Chain authentication request */
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crde = crda->crd_next;
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} else {
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crde = crp->crp_desc;
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}
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/* Crypto operation descriptor */
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crp->crp_ilen = m->m_pkthdr.len; /* Total input length */
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crp->crp_flags = CRYPTO_F_IMBUF;
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crp->crp_buf = m;
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crp->crp_callback = esp_input_cb;
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crp->crp_sid = sav->tdb_cryptoid;
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crp->crp_opaque = tc;
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/* These are passed as-is to the callback */
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tc->tc_spi = sav->spi;
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tc->tc_dst = sav->sah->saidx.dst;
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tc->tc_proto = sav->sah->saidx.proto;
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tc->tc_protoff = protoff;
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tc->tc_skip = skip;
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/* Decryption descriptor */
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if (espx) {
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IPSEC_ASSERT(crde != NULL, ("esp_input: null esp crypto descriptor"));
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crde->crd_skip = skip + hlen;
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crde->crd_len = m->m_pkthdr.len - (skip + hlen + alen);
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crde->crd_inject = skip + hlen - sav->ivlen;
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crde->crd_alg = espx->type;
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crde->crd_key = _KEYBUF(sav->key_enc);
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crde->crd_klen = _KEYBITS(sav->key_enc);
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/* XXX Rounds ? */
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}
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if (mtag == NULL)
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return crypto_dispatch(crp);
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else
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return esp_input_cb(crp);
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}
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#ifdef INET6
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#define IPSEC_COMMON_INPUT_CB(m, sav, skip, protoff, mtag) do { \
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if (saidx->dst.sa.sa_family == AF_INET6) { \
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error = ipsec6_common_input_cb(m, sav, skip, protoff, mtag); \
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} else { \
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error = ipsec4_common_input_cb(m, sav, skip, protoff, mtag); \
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} \
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} while (0)
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#else
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#define IPSEC_COMMON_INPUT_CB(m, sav, skip, protoff, mtag) \
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(error = ipsec4_common_input_cb(m, sav, skip, protoff, mtag))
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#endif
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/*
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* ESP input callback from the crypto driver.
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*/
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static int
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esp_input_cb(struct cryptop *crp)
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{
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u_int8_t lastthree[3], aalg[AH_HMAC_HASHLEN];
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int s, hlen, skip, protoff, error;
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struct mbuf *m;
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struct cryptodesc *crd;
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struct auth_hash *esph;
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struct enc_xform *espx;
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struct tdb_crypto *tc;
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struct m_tag *mtag;
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struct secasvar *sav;
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struct secasindex *saidx;
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void *ptr;
|
|
u_int16_t dport = 0;
|
|
u_int16_t sport = 0;
|
|
#ifdef IPSEC_NAT_T
|
|
struct m_tag * tag = NULL;
|
|
#endif
|
|
|
|
crd = crp->crp_desc;
|
|
IPSEC_ASSERT(crd != NULL, ("esp_input_cb: null crypto descriptor!"));
|
|
|
|
tc = (struct tdb_crypto *) crp->crp_opaque;
|
|
IPSEC_ASSERT(tc != NULL, ("esp_input_cb: null opaque crypto data area!"));
|
|
skip = tc->tc_skip;
|
|
protoff = tc->tc_protoff;
|
|
mtag = (struct m_tag *) tc->tc_ptr;
|
|
m = (struct mbuf *) crp->crp_buf;
|
|
|
|
#ifdef IPSEC_NAT_T
|
|
/* find the source port for NAT-T */
|
|
if ((tag = m_tag_find(m, PACKET_TAG_IPSEC_NAT_T_PORTS, NULL))) {
|
|
sport = ((u_int16_t *)(tag + 1))[0];
|
|
dport = ((u_int16_t *)(tag + 1))[1];
|
|
}
|
|
#endif
|
|
|
|
s = splsoftnet();
|
|
|
|
sav = KEY_ALLOCSA(&tc->tc_dst, tc->tc_proto, tc->tc_spi, sport, dport);
|
|
if (sav == NULL) {
|
|
ESP_STATINC(ESP_STAT_NOTDB);
|
|
DPRINTF(("esp_input_cb: SA expired while in crypto "
|
|
"(SA %s/%08lx proto %u)\n", ipsec_address(&tc->tc_dst),
|
|
(u_long) ntohl(tc->tc_spi), tc->tc_proto));
|
|
error = ENOBUFS; /*XXX*/
|
|
goto bad;
|
|
}
|
|
|
|
saidx = &sav->sah->saidx;
|
|
IPSEC_ASSERT(saidx->dst.sa.sa_family == AF_INET ||
|
|
saidx->dst.sa.sa_family == AF_INET6,
|
|
("ah_input_cb: unexpected protocol family %u",
|
|
saidx->dst.sa.sa_family));
|
|
|
|
esph = sav->tdb_authalgxform;
|
|
espx = sav->tdb_encalgxform;
|
|
|
|
/* Check for crypto errors */
|
|
if (crp->crp_etype) {
|
|
/* Reset the session ID */
|
|
if (sav->tdb_cryptoid != 0)
|
|
sav->tdb_cryptoid = crp->crp_sid;
|
|
|
|
if (crp->crp_etype == EAGAIN) {
|
|
KEY_FREESAV(&sav);
|
|
splx(s);
|
|
return crypto_dispatch(crp);
|
|
}
|
|
|
|
ESP_STATINC(ESP_STAT_NOXFORM);
|
|
DPRINTF(("esp_input_cb: crypto error %d\n", crp->crp_etype));
|
|
error = crp->crp_etype;
|
|
goto bad;
|
|
}
|
|
|
|
/* Shouldn't happen... */
|
|
if (m == NULL) {
|
|
ESP_STATINC(ESP_STAT_CRYPTO);
|
|
DPRINTF(("esp_input_cb: bogus returned buffer from crypto\n"));
|
|
error = EINVAL;
|
|
goto bad;
|
|
}
|
|
ESP_STATINC(ESP_STAT_HIST + sav->alg_enc);
|
|
|
|
/* If authentication was performed, check now. */
|
|
if (esph != NULL) {
|
|
/*
|
|
* If we have a tag, it means an IPsec-aware NIC did
|
|
* the verification for us. Otherwise we need to
|
|
* check the authentication calculation.
|
|
*/
|
|
AH_STATINC(AH_STAT_HIST + sav->alg_auth);
|
|
if (mtag == NULL) {
|
|
/* Copy the authenticator from the packet */
|
|
m_copydata(m, m->m_pkthdr.len - esph->authsize,
|
|
esph->authsize, aalg);
|
|
|
|
ptr = (tc + 1);
|
|
|
|
/* Verify authenticator */
|
|
if (bcmp(ptr, aalg, esph->authsize) != 0) {
|
|
DPRINTF(("esp_input_cb: "
|
|
"authentication hash mismatch for packet in SA %s/%08lx\n",
|
|
ipsec_address(&saidx->dst),
|
|
(u_long) ntohl(sav->spi)));
|
|
ESP_STATINC(ESP_STAT_BADAUTH);
|
|
error = EACCES;
|
|
goto bad;
|
|
}
|
|
}
|
|
|
|
/* Remove trailing authenticator */
|
|
m_adj(m, -(esph->authsize));
|
|
}
|
|
|
|
/* Release the crypto descriptors */
|
|
free(tc, M_XDATA), tc = NULL;
|
|
crypto_freereq(crp), crp = NULL;
|
|
|
|
/*
|
|
* Packet is now decrypted.
|
|
*/
|
|
m->m_flags |= M_DECRYPTED;
|
|
|
|
/*
|
|
* Update replay sequence number, if appropriate.
|
|
*/
|
|
if (sav->replay) {
|
|
u_int32_t seq;
|
|
|
|
m_copydata(m, skip + offsetof(struct newesp, esp_seq),
|
|
sizeof (seq), &seq);
|
|
if (ipsec_updatereplay(ntohl(seq), sav)) {
|
|
DPRINTF(("%s: packet replay check for %s\n", __func__,
|
|
ipsec_logsastr(sav)));
|
|
ESP_STATINC(ESP_STAT_REPLAY);
|
|
error = ENOBUFS;
|
|
goto bad;
|
|
}
|
|
}
|
|
|
|
/* Determine the ESP header length */
|
|
if (sav->flags & SADB_X_EXT_OLD)
|
|
hlen = sizeof (struct esp) + sav->ivlen;
|
|
else
|
|
hlen = sizeof (struct newesp) + sav->ivlen;
|
|
|
|
/* Remove the ESP header and IV from the mbuf. */
|
|
error = m_striphdr(m, skip, hlen);
|
|
if (error) {
|
|
ESP_STATINC(ESP_STAT_HDROPS);
|
|
DPRINTF(("esp_input_cb: bad mbuf chain, SA %s/%08lx\n",
|
|
ipsec_address(&sav->sah->saidx.dst),
|
|
(u_long) ntohl(sav->spi)));
|
|
goto bad;
|
|
}
|
|
|
|
/* Save the last three bytes of decrypted data */
|
|
m_copydata(m, m->m_pkthdr.len - 3, 3, lastthree);
|
|
|
|
/* Verify pad length */
|
|
if (lastthree[1] + 2 > m->m_pkthdr.len - skip) {
|
|
ESP_STATINC(ESP_STAT_BADILEN);
|
|
DPRINTF(("esp_input_cb: invalid padding length %d "
|
|
"for %u byte packet in SA %s/%08lx\n",
|
|
lastthree[1], m->m_pkthdr.len - skip,
|
|
ipsec_address(&sav->sah->saidx.dst),
|
|
(u_long) ntohl(sav->spi)));
|
|
error = EINVAL;
|
|
goto bad;
|
|
}
|
|
|
|
/* Verify correct decryption by checking the last padding bytes */
|
|
if ((sav->flags & SADB_X_EXT_PMASK) != SADB_X_EXT_PRAND) {
|
|
if (lastthree[1] != lastthree[0] && lastthree[1] != 0) {
|
|
ESP_STATINC(ESP_STAT_BADENC);
|
|
DPRINTF(("esp_input_cb: decryption failed "
|
|
"for packet in SA %s/%08lx\n",
|
|
ipsec_address(&sav->sah->saidx.dst),
|
|
(u_long) ntohl(sav->spi)));
|
|
DPRINTF(("esp_input_cb: %x %x\n", lastthree[0], lastthree[1]));
|
|
error = EINVAL;
|
|
goto bad;
|
|
}
|
|
}
|
|
|
|
/* Trim the mbuf chain to remove trailing authenticator and padding */
|
|
m_adj(m, -(lastthree[1] + 2));
|
|
|
|
/* Restore the Next Protocol field */
|
|
m = m_copyback_cow(m, protoff, sizeof (u_int8_t), lastthree + 2,
|
|
M_DONTWAIT);
|
|
|
|
if (m == NULL) {
|
|
ESP_STATINC(ESP_STAT_CRYPTO);
|
|
DPRINTF(("esp_input_cb: failed to allocate mbuf\n"));
|
|
error = ENOBUFS;
|
|
goto bad;
|
|
}
|
|
|
|
IPSEC_COMMON_INPUT_CB(m, sav, skip, protoff, mtag);
|
|
|
|
KEY_FREESAV(&sav);
|
|
splx(s);
|
|
return error;
|
|
bad:
|
|
if (sav)
|
|
KEY_FREESAV(&sav);
|
|
splx(s);
|
|
if (m != NULL)
|
|
m_freem(m);
|
|
if (tc != NULL)
|
|
free(tc, M_XDATA);
|
|
if (crp != NULL)
|
|
crypto_freereq(crp);
|
|
return error;
|
|
}
|
|
|
|
/*
|
|
* ESP output routine, called by ipsec[46]_process_packet().
|
|
*/
|
|
static int
|
|
esp_output(
|
|
struct mbuf *m,
|
|
struct ipsecrequest *isr,
|
|
struct mbuf **mp,
|
|
int skip,
|
|
int protoff
|
|
)
|
|
{
|
|
struct enc_xform *espx;
|
|
struct auth_hash *esph;
|
|
int hlen, rlen, plen, padding, blks, alen, i, roff;
|
|
struct mbuf *mo = (struct mbuf *) NULL;
|
|
struct tdb_crypto *tc;
|
|
struct secasvar *sav;
|
|
struct secasindex *saidx;
|
|
unsigned char *pad;
|
|
u_int8_t prot;
|
|
int error, maxpacketsize;
|
|
|
|
struct cryptodesc *crde = NULL, *crda = NULL;
|
|
struct cryptop *crp;
|
|
|
|
IPSEC_SPLASSERT_SOFTNET("esp_output");
|
|
|
|
sav = isr->sav;
|
|
IPSEC_ASSERT(sav != NULL, ("esp_output: null SA"));
|
|
esph = sav->tdb_authalgxform;
|
|
espx = sav->tdb_encalgxform;
|
|
IPSEC_ASSERT(espx != NULL, ("esp_output: null encoding xform"));
|
|
|
|
if (sav->flags & SADB_X_EXT_OLD)
|
|
hlen = sizeof (struct esp) + sav->ivlen;
|
|
else
|
|
hlen = sizeof (struct newesp) + sav->ivlen;
|
|
|
|
rlen = m->m_pkthdr.len - skip; /* Raw payload length. */
|
|
/*
|
|
* NB: The null encoding transform has a blocksize of 4
|
|
* so that headers are properly aligned.
|
|
*/
|
|
blks = espx->blocksize; /* IV blocksize */
|
|
|
|
/* XXX clamp padding length a la KAME??? */
|
|
padding = ((blks - ((rlen + 2) % blks)) % blks) + 2;
|
|
plen = rlen + padding; /* Padded payload length. */
|
|
|
|
if (esph)
|
|
alen = AH_HMAC_HASHLEN;
|
|
else
|
|
alen = 0;
|
|
|
|
ESP_STATINC(ESP_STAT_OUTPUT);
|
|
|
|
saidx = &sav->sah->saidx;
|
|
/* Check for maximum packet size violations. */
|
|
switch (saidx->dst.sa.sa_family) {
|
|
#ifdef INET
|
|
case AF_INET:
|
|
maxpacketsize = IP_MAXPACKET;
|
|
break;
|
|
#endif /* INET */
|
|
#ifdef INET6
|
|
case AF_INET6:
|
|
maxpacketsize = IPV6_MAXPACKET;
|
|
break;
|
|
#endif /* INET6 */
|
|
default:
|
|
DPRINTF(("esp_output: unknown/unsupported protocol "
|
|
"family %d, SA %s/%08lx\n",
|
|
saidx->dst.sa.sa_family, ipsec_address(&saidx->dst),
|
|
(u_long) ntohl(sav->spi)));
|
|
ESP_STATINC(ESP_STAT_NOPF);
|
|
error = EPFNOSUPPORT;
|
|
goto bad;
|
|
}
|
|
if (skip + hlen + rlen + padding + alen > maxpacketsize) {
|
|
DPRINTF(("esp_output: packet in SA %s/%08lx got too big "
|
|
"(len %u, max len %u)\n",
|
|
ipsec_address(&saidx->dst), (u_long) ntohl(sav->spi),
|
|
skip + hlen + rlen + padding + alen, maxpacketsize));
|
|
ESP_STATINC(ESP_STAT_TOOBIG);
|
|
error = EMSGSIZE;
|
|
goto bad;
|
|
}
|
|
|
|
/* Update the counters. */
|
|
ESP_STATADD(ESP_STAT_OUTPUT, m->m_pkthdr.len - skip);
|
|
|
|
m = m_clone(m);
|
|
if (m == NULL) {
|
|
DPRINTF(("esp_output: cannot clone mbuf chain, SA %s/%08lx\n",
|
|
ipsec_address(&saidx->dst), (u_long) ntohl(sav->spi)));
|
|
ESP_STATINC(ESP_STAT_HDROPS);
|
|
error = ENOBUFS;
|
|
goto bad;
|
|
}
|
|
|
|
/* Inject ESP header. */
|
|
mo = m_makespace(m, skip, hlen, &roff);
|
|
if (mo == NULL) {
|
|
DPRINTF(("esp_output: failed to inject %u byte ESP hdr for SA "
|
|
"%s/%08lx\n",
|
|
hlen, ipsec_address(&saidx->dst),
|
|
(u_long) ntohl(sav->spi)));
|
|
ESP_STATINC(ESP_STAT_HDROPS); /* XXX diffs from openbsd */
|
|
error = ENOBUFS;
|
|
goto bad;
|
|
}
|
|
|
|
/* Initialize ESP header. */
|
|
bcopy(&sav->spi, mtod(mo, char *) + roff, sizeof(u_int32_t));
|
|
if (sav->replay) {
|
|
u_int32_t replay;
|
|
|
|
#ifdef IPSEC_DEBUG
|
|
/* Emulate replay attack when ipsec_replay is TRUE. */
|
|
if (!ipsec_replay)
|
|
#endif
|
|
sav->replay->count++;
|
|
|
|
replay = htonl(sav->replay->count);
|
|
bcopy(&replay,
|
|
mtod(mo,char *) + roff + sizeof(u_int32_t),
|
|
sizeof(u_int32_t));
|
|
}
|
|
|
|
/*
|
|
* Add padding -- better to do it ourselves than use the crypto engine,
|
|
* although if/when we support compression, we'd have to do that.
|
|
*/
|
|
pad = (u_char *) m_pad(m, padding + alen);
|
|
if (pad == NULL) {
|
|
DPRINTF(("esp_output: m_pad failed for SA %s/%08lx\n",
|
|
ipsec_address(&saidx->dst), (u_long) ntohl(sav->spi)));
|
|
m = NULL; /* NB: free'd by m_pad */
|
|
error = ENOBUFS;
|
|
goto bad;
|
|
}
|
|
|
|
/*
|
|
* Add padding: random, zero, or self-describing.
|
|
* XXX catch unexpected setting
|
|
*/
|
|
switch (sav->flags & SADB_X_EXT_PMASK) {
|
|
case SADB_X_EXT_PRAND:
|
|
(void) read_random(pad, padding - 2);
|
|
break;
|
|
case SADB_X_EXT_PZERO:
|
|
bzero(pad, padding - 2);
|
|
break;
|
|
case SADB_X_EXT_PSEQ:
|
|
for (i = 0; i < padding - 2; i++)
|
|
pad[i] = i+1;
|
|
break;
|
|
}
|
|
|
|
/* Fix padding length and Next Protocol in padding itself. */
|
|
pad[padding - 2] = padding - 2;
|
|
m_copydata(m, protoff, sizeof(u_int8_t), pad + padding - 1);
|
|
|
|
/* Fix Next Protocol in IPv4/IPv6 header. */
|
|
prot = IPPROTO_ESP;
|
|
m_copyback(m, protoff, sizeof(u_int8_t), (u_char *) &prot);
|
|
|
|
/* Get crypto descriptors. */
|
|
crp = crypto_getreq(esph && espx ? 2 : 1);
|
|
if (crp == NULL) {
|
|
DPRINTF(("esp_output: failed to acquire crypto descriptors\n"));
|
|
ESP_STATINC(ESP_STAT_CRYPTO);
|
|
error = ENOBUFS;
|
|
goto bad;
|
|
}
|
|
|
|
if (espx) {
|
|
crde = crp->crp_desc;
|
|
crda = crde->crd_next;
|
|
|
|
/* Encryption descriptor. */
|
|
crde->crd_skip = skip + hlen;
|
|
crde->crd_len = m->m_pkthdr.len - (skip + hlen + alen);
|
|
crde->crd_flags = CRD_F_ENCRYPT;
|
|
crde->crd_inject = skip + hlen - sav->ivlen;
|
|
|
|
/* Encryption operation. */
|
|
crde->crd_alg = espx->type;
|
|
crde->crd_key = _KEYBUF(sav->key_enc);
|
|
crde->crd_klen = _KEYBITS(sav->key_enc);
|
|
/* XXX Rounds ? */
|
|
} else
|
|
crda = crp->crp_desc;
|
|
|
|
/* IPsec-specific opaque crypto info. */
|
|
tc = (struct tdb_crypto *) malloc(sizeof(struct tdb_crypto),
|
|
M_XDATA, M_NOWAIT|M_ZERO);
|
|
if (tc == NULL) {
|
|
crypto_freereq(crp);
|
|
DPRINTF(("esp_output: failed to allocate tdb_crypto\n"));
|
|
ESP_STATINC(ESP_STAT_CRYPTO);
|
|
error = ENOBUFS;
|
|
goto bad;
|
|
}
|
|
|
|
/* Callback parameters */
|
|
tc->tc_isr = isr;
|
|
tc->tc_spi = sav->spi;
|
|
tc->tc_dst = saidx->dst;
|
|
tc->tc_proto = saidx->proto;
|
|
|
|
/* Crypto operation descriptor. */
|
|
crp->crp_ilen = m->m_pkthdr.len; /* Total input length. */
|
|
crp->crp_flags = CRYPTO_F_IMBUF;
|
|
crp->crp_buf = m;
|
|
crp->crp_callback = esp_output_cb;
|
|
crp->crp_opaque = tc;
|
|
crp->crp_sid = sav->tdb_cryptoid;
|
|
|
|
if (esph) {
|
|
/* Authentication descriptor. */
|
|
crda->crd_skip = skip;
|
|
crda->crd_len = m->m_pkthdr.len - (skip + alen);
|
|
crda->crd_inject = m->m_pkthdr.len - alen;
|
|
|
|
/* Authentication operation. */
|
|
crda->crd_alg = esph->type;
|
|
crda->crd_key = _KEYBUF(sav->key_auth);
|
|
crda->crd_klen = _KEYBITS(sav->key_auth);
|
|
}
|
|
|
|
return crypto_dispatch(crp);
|
|
bad:
|
|
if (m)
|
|
m_freem(m);
|
|
return (error);
|
|
}
|
|
|
|
/*
|
|
* ESP output callback from the crypto driver.
|
|
*/
|
|
static int
|
|
esp_output_cb(struct cryptop *crp)
|
|
{
|
|
struct tdb_crypto *tc;
|
|
struct ipsecrequest *isr;
|
|
struct secasvar *sav;
|
|
struct mbuf *m;
|
|
int s, err, error;
|
|
|
|
tc = (struct tdb_crypto *) crp->crp_opaque;
|
|
IPSEC_ASSERT(tc != NULL, ("esp_output_cb: null opaque data area!"));
|
|
m = (struct mbuf *) crp->crp_buf;
|
|
|
|
s = splsoftnet();
|
|
|
|
isr = tc->tc_isr;
|
|
sav = KEY_ALLOCSA(&tc->tc_dst, tc->tc_proto, tc->tc_spi, 0, 0);
|
|
if (sav == NULL) {
|
|
ESP_STATINC(ESP_STAT_NOTDB);
|
|
DPRINTF(("esp_output_cb: SA expired while in crypto "
|
|
"(SA %s/%08lx proto %u)\n", ipsec_address(&tc->tc_dst),
|
|
(u_long) ntohl(tc->tc_spi), tc->tc_proto));
|
|
error = ENOBUFS; /*XXX*/
|
|
goto bad;
|
|
}
|
|
IPSEC_ASSERT(isr->sav == sav,
|
|
("esp_output_cb: SA changed was %p now %p\n", isr->sav, sav));
|
|
|
|
/* Check for crypto errors. */
|
|
if (crp->crp_etype) {
|
|
/* Reset session ID. */
|
|
if (sav->tdb_cryptoid != 0)
|
|
sav->tdb_cryptoid = crp->crp_sid;
|
|
|
|
if (crp->crp_etype == EAGAIN) {
|
|
KEY_FREESAV(&sav);
|
|
splx(s);
|
|
return crypto_dispatch(crp);
|
|
}
|
|
|
|
ESP_STATINC(ESP_STAT_NOXFORM);
|
|
DPRINTF(("esp_output_cb: crypto error %d\n", crp->crp_etype));
|
|
error = crp->crp_etype;
|
|
goto bad;
|
|
}
|
|
|
|
/* Shouldn't happen... */
|
|
if (m == NULL) {
|
|
ESP_STATINC(ESP_STAT_CRYPTO);
|
|
DPRINTF(("esp_output_cb: bogus returned buffer from crypto\n"));
|
|
error = EINVAL;
|
|
goto bad;
|
|
}
|
|
ESP_STATINC(ESP_STAT_HIST + sav->alg_enc);
|
|
if (sav->tdb_authalgxform != NULL)
|
|
AH_STATINC(sav->alg_auth + sav->alg_auth);
|
|
|
|
/* Release crypto descriptors. */
|
|
free(tc, M_XDATA);
|
|
crypto_freereq(crp);
|
|
|
|
#ifdef IPSEC_DEBUG
|
|
/* Emulate man-in-the-middle attack when ipsec_integrity is TRUE. */
|
|
if (ipsec_integrity) {
|
|
static unsigned char ipseczeroes[AH_HMAC_HASHLEN];
|
|
struct auth_hash *esph;
|
|
|
|
/*
|
|
* Corrupt HMAC if we want to test integrity verification of
|
|
* the other side.
|
|
*/
|
|
esph = sav->tdb_authalgxform;
|
|
if (esph != NULL) {
|
|
m_copyback(m, m->m_pkthdr.len - AH_HMAC_HASHLEN,
|
|
AH_HMAC_HASHLEN, ipseczeroes);
|
|
}
|
|
}
|
|
#endif
|
|
|
|
/* NB: m is reclaimed by ipsec_process_done. */
|
|
err = ipsec_process_done(m, isr);
|
|
KEY_FREESAV(&sav);
|
|
splx(s);
|
|
return err;
|
|
bad:
|
|
if (sav)
|
|
KEY_FREESAV(&sav);
|
|
splx(s);
|
|
if (m)
|
|
m_freem(m);
|
|
free(tc, M_XDATA);
|
|
crypto_freereq(crp);
|
|
return error;
|
|
}
|
|
|
|
static struct xformsw esp_xformsw = {
|
|
XF_ESP, XFT_CONF|XFT_AUTH, "IPsec ESP",
|
|
esp_init, esp_zeroize, esp_input,
|
|
esp_output,
|
|
NULL,
|
|
};
|
|
|
|
INITFN void
|
|
esp_attach(void)
|
|
{
|
|
|
|
espstat_percpu = percpu_alloc(sizeof(uint64_t) * ESP_NSTATS);
|
|
|
|
#define MAXIV(xform) \
|
|
if (xform.blocksize > esp_max_ivlen) \
|
|
esp_max_ivlen = xform.blocksize \
|
|
|
|
esp_max_ivlen = 0;
|
|
MAXIV(enc_xform_des); /* SADB_EALG_DESCBC */
|
|
MAXIV(enc_xform_3des); /* SADB_EALG_3DESCBC */
|
|
MAXIV(enc_xform_rijndael128); /* SADB_X_EALG_AES */
|
|
MAXIV(enc_xform_blf); /* SADB_X_EALG_BLOWFISHCBC */
|
|
MAXIV(enc_xform_cast5); /* SADB_X_EALG_CAST128CBC */
|
|
MAXIV(enc_xform_skipjack); /* SADB_X_EALG_SKIPJACK */
|
|
MAXIV(enc_xform_null); /* SADB_EALG_NULL */
|
|
|
|
xform_register(&esp_xformsw);
|
|
#undef MAXIV
|
|
}
|
|
#ifdef __FreeBSD__
|
|
SYSINIT(esp_xform_init, SI_SUB_DRIVERS, SI_ORDER_FIRST, esp_attach, NULL)
|
|
#else
|
|
#endif
|