defines the keys differently than NIST does, so we have to muck with key lengths and nonce/IVs to be standard compliant... Remove the iv from secasvar as it was unused... Add a counter protected by a mutex to ensure that the counter for GCM and ICM will never be repeated.. This is a requirement for security.. I would use atomics, but we don't have a 64bit one on all platforms.. Fix a bug where IPsec was depending upon the OCF to ensure that the blocksize was always at least 4 bytes to maintain alignment... Move this logic into IPsec so changes to OCF won't break IPsec... In one place, espx was always non-NULL, so don't test that it's non-NULL before doing work.. minor style cleanups... drop setting key and klen as they were not used... Enforce that OCF won't pass invalid key lengths to AES that would panic the machine... This was has been tested by others too... I tested this against NetBSD 6.1.5 using mini-test suite in https://github.com/jmgurney/ipseccfgs and the only things that don't pass are keyed md5 and sha1, and 3des-deriv (setkey syntax error), all other modes listed in setkey's man page... The nice thing is that NetBSD uses setkey, so same config files were used on both... Reviewed by: gnn
1026 lines
27 KiB
C
1026 lines
27 KiB
C
/* $FreeBSD$ */
|
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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 "opt_inet.h"
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#include "opt_inet6.h"
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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/lock.h>
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#include <sys/random.h>
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#include <sys/rwlock.h>
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#include <sys/sysctl.h>
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#include <sys/mutex.h>
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#include <machine/atomic.h>
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#include <net/if.h>
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#include <net/vnet.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 <netipsec/ipsec.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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#include <netinet6/ip6_ecn.h>
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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 <opencrypto/cryptodev.h>
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#include <opencrypto/xform.h>
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VNET_DEFINE(int, esp_enable) = 1;
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VNET_PCPUSTAT_DEFINE(struct espstat, espstat);
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VNET_PCPUSTAT_SYSINIT(espstat);
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#ifdef VIMAGE
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VNET_PCPUSTAT_SYSUNINIT(espstat);
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#endif /* VIMAGE */
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SYSCTL_DECL(_net_inet_esp);
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SYSCTL_INT(_net_inet_esp, OID_AUTO, esp_enable,
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CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(esp_enable), 0, "");
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SYSCTL_VNET_PCPUSTAT(_net_inet_esp, IPSECCTL_STATS, stats,
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struct espstat, espstat,
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"ESP statistics (struct espstat, netipsec/esp_var.h");
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|
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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_EALG_NULL:
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return &enc_xform_null;
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case SADB_X_EALG_CAMELLIACBC:
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return &enc_xform_camellia;
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case SADB_X_EALG_AESCTR:
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return &enc_xform_aes_icm;
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case SADB_X_EALG_AESGCM16:
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return &enc_xform_aes_nist_gcm;
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case SADB_X_EALG_AESGMAC:
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return &enc_xform_aes_nist_gmac;
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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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("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) + EALG_MAX_BLOCK_LEN + 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(("%s: unsupported encryption algorithm %d\n",
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__func__, 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(("%s: no encoding key for %s algorithm\n",
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__func__, 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)) ==
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SADB_X_EXT_IV4B) {
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DPRINTF(("%s: 4-byte IV not supported with protocol\n",
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__func__));
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return EINVAL;
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}
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/* subtract off the salt, RFC4106, 8.1 and RFC3686, 5.1 */
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keylen = _KEYLEN(sav->key_enc) - SAV_ISCTRORGCM(sav) * 4;
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if (txform->minkey > keylen || keylen > txform->maxkey) {
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DPRINTF(("%s: invalid key length %u, must be in the range "
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"[%u..%u] for algorithm %s\n", __func__,
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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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if (SAV_ISCTRORGCM(sav))
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sav->ivlen = 8; /* RFC4106 3.1 and RFC3686 3.1 */
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else
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sav->ivlen = (txform == &enc_xform_null ? 0 : txform->ivsize);
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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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/*
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* Whenever AES-GCM is used for encryption, one
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* of the AES authentication algorithms is chosen
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* as well, based on the key size.
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*/
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if (sav->alg_enc == SADB_X_EALG_AESGCM16) {
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switch (keylen) {
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case AES_128_GMAC_KEY_LEN:
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sav->alg_auth = SADB_X_AALG_AES128GMAC;
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sav->tdb_authalgxform = &auth_hash_nist_gmac_aes_128;
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break;
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case AES_192_GMAC_KEY_LEN:
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sav->alg_auth = SADB_X_AALG_AES192GMAC;
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sav->tdb_authalgxform = &auth_hash_nist_gmac_aes_192;
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break;
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case AES_256_GMAC_KEY_LEN:
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sav->alg_auth = SADB_X_AALG_AES256GMAC;
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sav->tdb_authalgxform = &auth_hash_nist_gmac_aes_256;
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break;
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default:
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DPRINTF(("%s: invalid key length %u"
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"for algorithm %s\n", __func__,
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keylen, txform->name));
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return EINVAL;
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}
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bzero(&cria, sizeof(cria));
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cria.cri_alg = sav->tdb_authalgxform->type;
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cria.cri_key = sav->key_enc->key_data;
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cria.cri_klen = _KEYBITS(sav->key_enc) - SAV_ISGCM(sav) * 32;
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}
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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_key = sav->key_enc->key_data;
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crie.cri_klen = _KEYBITS(sav->key_enc) - SAV_ISCTRORGCM(sav) * 32;
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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, V_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, V_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, V_crypto_support);
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} else {
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/* XXX cannot happen? */
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DPRINTF(("%s: no encoding OR authentication xform!\n",
|
|
__func__));
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error = EINVAL;
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|
}
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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);
|
|
|
|
if (sav->key_enc)
|
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bzero(sav->key_enc->key_data, _KEYLEN(sav->key_enc));
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sav->tdb_encalgxform = NULL;
|
|
sav->tdb_xform = NULL;
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return error;
|
|
}
|
|
|
|
/*
|
|
* ESP input processing, called (eventually) through the protocol switch.
|
|
*/
|
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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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char buf[128];
|
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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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uint8_t *ivp;
|
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int plen, alen, hlen;
|
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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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|
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IPSEC_ASSERT(sav != NULL, ("null SA"));
|
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IPSEC_ASSERT(sav->tdb_encalgxform != NULL, ("null encoding xform"));
|
|
|
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/* Valid IP Packet length ? */
|
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if ( (skip&3) || (m->m_pkthdr.len&3) ){
|
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DPRINTF(("%s: misaligned packet, skip %u pkt len %u",
|
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__func__, skip, m->m_pkthdr.len));
|
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ESPSTAT_INC(esps_badilen);
|
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m_freem(m);
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return EINVAL;
|
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}
|
|
/* XXX don't pullup, just copy header */
|
|
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 and auth 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
|
|
hlen = sizeof (struct newesp) + sav->ivlen;
|
|
|
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alen = xform_ah_authsize(esph);
|
|
|
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/*
|
|
* Verify payload length is multiple of encryption algorithm
|
|
* block size.
|
|
*
|
|
* NB: This works for the null algorithm because the blocksize
|
|
* is 4 and all packets must be 4-byte aligned regardless
|
|
* of the algorithm.
|
|
*/
|
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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(("%s: payload of %d octets not a multiple of %d octets,"
|
|
" SA %s/%08lx\n", __func__, plen, espx->blocksize,
|
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ipsec_address(&sav->sah->saidx.dst, buf, sizeof(buf)),
|
|
(u_long)ntohl(sav->spi)));
|
|
ESPSTAT_INC(esps_badilen);
|
|
m_freem(m);
|
|
return EINVAL;
|
|
}
|
|
|
|
/*
|
|
* Check sequence number.
|
|
*/
|
|
if (esph != NULL && sav->replay != NULL &&
|
|
!ipsec_chkreplay(ntohl(esp->esp_seq), sav)) {
|
|
DPRINTF(("%s: packet replay check for %s\n", __func__,
|
|
ipsec_logsastr(sav, buf, sizeof(buf)))); /*XXX*/
|
|
ESPSTAT_INC(esps_replay);
|
|
m_freem(m);
|
|
return ENOBUFS; /*XXX*/
|
|
}
|
|
|
|
/* Update the counters */
|
|
ESPSTAT_ADD(esps_ibytes, m->m_pkthdr.len - (skip + hlen + alen));
|
|
|
|
/* Get crypto descriptors */
|
|
crp = crypto_getreq(esph && espx ? 2 : 1);
|
|
if (crp == NULL) {
|
|
DPRINTF(("%s: failed to acquire crypto descriptors\n",
|
|
__func__));
|
|
ESPSTAT_INC(esps_crypto);
|
|
m_freem(m);
|
|
return ENOBUFS;
|
|
}
|
|
|
|
/* Get IPsec-specific opaque pointer */
|
|
tc = (struct tdb_crypto *) malloc(sizeof(struct tdb_crypto) + alen,
|
|
M_XDATA, M_NOWAIT | M_ZERO);
|
|
if (tc == NULL) {
|
|
crypto_freereq(crp);
|
|
DPRINTF(("%s: failed to allocate tdb_crypto\n", __func__));
|
|
ESPSTAT_INC(esps_crypto);
|
|
m_freem(m);
|
|
return ENOBUFS;
|
|
}
|
|
|
|
if (esph != NULL) {
|
|
struct cryptodesc *crda = crp->crp_desc;
|
|
|
|
IPSEC_ASSERT(crda != NULL, ("null ah crypto descriptor"));
|
|
|
|
/* Authentication descriptor */
|
|
crda->crd_skip = skip;
|
|
if (SAV_ISGCM(sav))
|
|
crda->crd_len = 8; /* RFC4106 5, SPI + SN */
|
|
else
|
|
crda->crd_len = m->m_pkthdr.len - (skip + alen);
|
|
crda->crd_inject = m->m_pkthdr.len - alen;
|
|
|
|
crda->crd_alg = esph->type;
|
|
|
|
/* Copy the authenticator */
|
|
m_copydata(m, m->m_pkthdr.len - alen, alen,
|
|
(caddr_t) (tc + 1));
|
|
|
|
/* Chain authentication request */
|
|
crde = crda->crd_next;
|
|
} else {
|
|
crde = crp->crp_desc;
|
|
}
|
|
|
|
/* Crypto operation descriptor */
|
|
crp->crp_ilen = m->m_pkthdr.len; /* Total input length */
|
|
crp->crp_flags = CRYPTO_F_IMBUF | CRYPTO_F_CBIFSYNC;
|
|
crp->crp_buf = (caddr_t) m;
|
|
crp->crp_callback = esp_input_cb;
|
|
crp->crp_sid = sav->tdb_cryptoid;
|
|
crp->crp_opaque = (caddr_t) tc;
|
|
|
|
/* These are passed as-is to the callback */
|
|
tc->tc_spi = sav->spi;
|
|
tc->tc_dst = sav->sah->saidx.dst;
|
|
tc->tc_proto = sav->sah->saidx.proto;
|
|
tc->tc_protoff = protoff;
|
|
tc->tc_skip = skip;
|
|
KEY_ADDREFSA(sav);
|
|
tc->tc_sav = sav;
|
|
|
|
/* Decryption descriptor */
|
|
IPSEC_ASSERT(crde != NULL, ("null esp crypto descriptor"));
|
|
crde->crd_skip = skip + hlen;
|
|
crde->crd_len = m->m_pkthdr.len - (skip + hlen + alen);
|
|
crde->crd_inject = skip + hlen - sav->ivlen;
|
|
|
|
if (SAV_ISCTRORGCM(sav)) {
|
|
ivp = &crde->crd_iv[0];
|
|
|
|
/* GCM IV Format: RFC4106 4 */
|
|
/* CTR IV Format: RFC3686 4 */
|
|
/* Salt is last four bytes of key, RFC4106 8.1 */
|
|
/* Nonce is last four bytes of key, RFC3686 5.1 */
|
|
memcpy(ivp, sav->key_enc->key_data +
|
|
_KEYLEN(sav->key_enc) - 4, 4);
|
|
|
|
if (SAV_ISCTR(sav)) {
|
|
/* Initial block counter is 1, RFC3686 4 */
|
|
be32enc(&ivp[sav->ivlen + 4], 1);
|
|
}
|
|
|
|
m_copydata(m, skip + hlen - sav->ivlen, sav->ivlen, &ivp[4]);
|
|
crde->crd_flags |= CRD_F_IV_EXPLICIT;
|
|
}
|
|
|
|
crde->crd_alg = espx->type;
|
|
|
|
return (crypto_dispatch(crp));
|
|
}
|
|
|
|
/*
|
|
* ESP input callback from the crypto driver.
|
|
*/
|
|
static int
|
|
esp_input_cb(struct cryptop *crp)
|
|
{
|
|
char buf[128];
|
|
u_int8_t lastthree[3], aalg[AH_HMAC_MAXHASHLEN];
|
|
int hlen, skip, protoff, error, alen;
|
|
struct mbuf *m;
|
|
struct cryptodesc *crd;
|
|
struct auth_hash *esph;
|
|
struct enc_xform *espx;
|
|
struct tdb_crypto *tc;
|
|
struct secasvar *sav;
|
|
struct secasindex *saidx;
|
|
caddr_t ptr;
|
|
|
|
crd = crp->crp_desc;
|
|
IPSEC_ASSERT(crd != NULL, ("null crypto descriptor!"));
|
|
|
|
tc = (struct tdb_crypto *) crp->crp_opaque;
|
|
IPSEC_ASSERT(tc != NULL, ("null opaque crypto data area!"));
|
|
skip = tc->tc_skip;
|
|
protoff = tc->tc_protoff;
|
|
m = (struct mbuf *) crp->crp_buf;
|
|
|
|
sav = tc->tc_sav;
|
|
IPSEC_ASSERT(sav != NULL, ("null SA!"));
|
|
|
|
saidx = &sav->sah->saidx;
|
|
IPSEC_ASSERT(saidx->dst.sa.sa_family == AF_INET ||
|
|
saidx->dst.sa.sa_family == AF_INET6,
|
|
("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)
|
|
return (crypto_dispatch(crp));
|
|
|
|
ESPSTAT_INC(esps_noxform);
|
|
DPRINTF(("%s: crypto error %d\n", __func__, crp->crp_etype));
|
|
error = crp->crp_etype;
|
|
goto bad;
|
|
}
|
|
|
|
/* Shouldn't happen... */
|
|
if (m == NULL) {
|
|
ESPSTAT_INC(esps_crypto);
|
|
DPRINTF(("%s: bogus returned buffer from crypto\n", __func__));
|
|
error = EINVAL;
|
|
goto bad;
|
|
}
|
|
ESPSTAT_INC(esps_hist[sav->alg_enc]);
|
|
|
|
/* If authentication was performed, check now. */
|
|
if (esph != NULL) {
|
|
alen = xform_ah_authsize(esph);
|
|
AHSTAT_INC(ahs_hist[sav->alg_auth]);
|
|
/* Copy the authenticator from the packet */
|
|
m_copydata(m, m->m_pkthdr.len - alen, alen, aalg);
|
|
ptr = (caddr_t) (tc + 1);
|
|
|
|
/* Verify authenticator */
|
|
if (timingsafe_bcmp(ptr, aalg, alen) != 0) {
|
|
DPRINTF(("%s: authentication hash mismatch for "
|
|
"packet in SA %s/%08lx\n", __func__,
|
|
ipsec_address(&saidx->dst, buf, sizeof(buf)),
|
|
(u_long) ntohl(sav->spi)));
|
|
ESPSTAT_INC(esps_badauth);
|
|
error = EACCES;
|
|
goto bad;
|
|
}
|
|
|
|
/* Remove trailing authenticator */
|
|
m_adj(m, -alen);
|
|
}
|
|
|
|
/* 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), (caddr_t) &seq);
|
|
if (ipsec_updatereplay(ntohl(seq), sav)) {
|
|
DPRINTF(("%s: packet replay check for %s\n", __func__,
|
|
ipsec_logsastr(sav, buf, sizeof(buf))));
|
|
ESPSTAT_INC(esps_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) {
|
|
ESPSTAT_INC(esps_hdrops);
|
|
DPRINTF(("%s: bad mbuf chain, SA %s/%08lx\n", __func__,
|
|
ipsec_address(&sav->sah->saidx.dst, buf, sizeof(buf)),
|
|
(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) {
|
|
ESPSTAT_INC(esps_badilen);
|
|
DPRINTF(("%s: invalid padding length %d for %u byte packet "
|
|
"in SA %s/%08lx\n", __func__, lastthree[1],
|
|
m->m_pkthdr.len - skip,
|
|
ipsec_address(&sav->sah->saidx.dst, buf, sizeof(buf)),
|
|
(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) {
|
|
ESPSTAT_INC(esps_badenc);
|
|
DPRINTF(("%s: decryption failed for packet in "
|
|
"SA %s/%08lx\n", __func__, ipsec_address(
|
|
&sav->sah->saidx.dst, buf, sizeof(buf)),
|
|
(u_long) ntohl(sav->spi)));
|
|
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_copyback(m, protoff, sizeof (u_int8_t), lastthree + 2);
|
|
|
|
switch (saidx->dst.sa.sa_family) {
|
|
#ifdef INET6
|
|
case AF_INET6:
|
|
error = ipsec6_common_input_cb(m, sav, skip, protoff);
|
|
break;
|
|
#endif
|
|
#ifdef INET
|
|
case AF_INET:
|
|
error = ipsec4_common_input_cb(m, sav, skip, protoff);
|
|
break;
|
|
#endif
|
|
default:
|
|
panic("%s: Unexpected address family: %d saidx=%p", __func__,
|
|
saidx->dst.sa.sa_family, saidx);
|
|
}
|
|
|
|
KEY_FREESAV(&sav);
|
|
return error;
|
|
bad:
|
|
if (sav)
|
|
KEY_FREESAV(&sav);
|
|
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)
|
|
{
|
|
char buf[INET6_ADDRSTRLEN];
|
|
struct enc_xform *espx;
|
|
struct auth_hash *esph;
|
|
uint8_t *ivp;
|
|
uint64_t cntr;
|
|
int hlen, rlen, 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;
|
|
|
|
sav = isr->sav;
|
|
IPSEC_ASSERT(sav != NULL, ("null SA"));
|
|
esph = sav->tdb_authalgxform;
|
|
espx = sav->tdb_encalgxform;
|
|
IPSEC_ASSERT(espx != NULL, ("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. */
|
|
/*
|
|
* RFC4303 2.4 Requires 4 byte alignment.
|
|
*/
|
|
blks = MAX(4, espx->blocksize); /* Cipher blocksize */
|
|
|
|
/* XXX clamp padding length a la KAME??? */
|
|
padding = ((blks - ((rlen + 2) % blks)) % blks) + 2;
|
|
|
|
alen = xform_ah_authsize(esph);
|
|
|
|
ESPSTAT_INC(esps_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(("%s: unknown/unsupported protocol "
|
|
"family %d, SA %s/%08lx\n", __func__,
|
|
saidx->dst.sa.sa_family, ipsec_address(&saidx->dst,
|
|
buf, sizeof(buf)), (u_long) ntohl(sav->spi)));
|
|
ESPSTAT_INC(esps_nopf);
|
|
error = EPFNOSUPPORT;
|
|
goto bad;
|
|
}
|
|
DPRINTF(("%s: skip %d hlen %d rlen %d padding %d alen %d blksd %d\n",
|
|
__func__, skip, hlen, rlen, padding, alen, blks));
|
|
if (skip + hlen + rlen + padding + alen > maxpacketsize) {
|
|
DPRINTF(("%s: packet in SA %s/%08lx got too big "
|
|
"(len %u, max len %u)\n", __func__,
|
|
ipsec_address(&saidx->dst, buf, sizeof(buf)),
|
|
(u_long) ntohl(sav->spi),
|
|
skip + hlen + rlen + padding + alen, maxpacketsize));
|
|
ESPSTAT_INC(esps_toobig);
|
|
error = EMSGSIZE;
|
|
goto bad;
|
|
}
|
|
|
|
/* Update the counters. */
|
|
ESPSTAT_ADD(esps_obytes, m->m_pkthdr.len - skip);
|
|
|
|
m = m_unshare(m, M_NOWAIT);
|
|
if (m == NULL) {
|
|
DPRINTF(("%s: cannot clone mbuf chain, SA %s/%08lx\n", __func__,
|
|
ipsec_address(&saidx->dst, buf, sizeof(buf)),
|
|
(u_long) ntohl(sav->spi)));
|
|
ESPSTAT_INC(esps_hdrops);
|
|
error = ENOBUFS;
|
|
goto bad;
|
|
}
|
|
|
|
/* Inject ESP header. */
|
|
mo = m_makespace(m, skip, hlen, &roff);
|
|
if (mo == NULL) {
|
|
DPRINTF(("%s: %u byte ESP hdr inject failed for SA %s/%08lx\n",
|
|
__func__, hlen, ipsec_address(&saidx->dst, buf,
|
|
sizeof(buf)), (u_long) ntohl(sav->spi)));
|
|
ESPSTAT_INC(esps_hdrops); /* XXX diffs from openbsd */
|
|
error = ENOBUFS;
|
|
goto bad;
|
|
}
|
|
|
|
/* Initialize ESP header. */
|
|
bcopy((caddr_t) &sav->spi, mtod(mo, caddr_t) + roff, sizeof(u_int32_t));
|
|
if (sav->replay) {
|
|
u_int32_t replay;
|
|
|
|
#ifdef REGRESSION
|
|
/* Emulate replay attack when ipsec_replay is TRUE. */
|
|
if (!V_ipsec_replay)
|
|
#endif
|
|
sav->replay->count++;
|
|
replay = htonl(sav->replay->count);
|
|
bcopy((caddr_t) &replay,
|
|
mtod(mo, caddr_t) + 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(("%s: m_pad failed for SA %s/%08lx\n", __func__,
|
|
ipsec_address(&saidx->dst, buf, sizeof(buf)),
|
|
(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 != NULL ? 2 : 1);
|
|
if (crp == NULL) {
|
|
DPRINTF(("%s: failed to acquire crypto descriptors\n",
|
|
__func__));
|
|
ESPSTAT_INC(esps_crypto);
|
|
error = ENOBUFS;
|
|
goto bad;
|
|
}
|
|
|
|
/* 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(("%s: failed to allocate tdb_crypto\n", __func__));
|
|
ESPSTAT_INC(esps_crypto);
|
|
error = ENOBUFS;
|
|
goto bad;
|
|
}
|
|
|
|
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;
|
|
if (SAV_ISCTRORGCM(sav)) {
|
|
ivp = &crde->crd_iv[0];
|
|
|
|
/* GCM IV Format: RFC4106 4 */
|
|
/* CTR IV Format: RFC3686 4 */
|
|
/* Salt is last four bytes of key, RFC4106 8.1 */
|
|
/* Nonce is last four bytes of key, RFC3686 5.1 */
|
|
memcpy(ivp, sav->key_enc->key_data +
|
|
_KEYLEN(sav->key_enc) - 4, 4);
|
|
SECASVAR_LOCK(sav);
|
|
cntr = sav->cntr++;
|
|
SECASVAR_UNLOCK(sav);
|
|
be64enc(&ivp[4], cntr);
|
|
|
|
if (SAV_ISCTR(sav)) {
|
|
/* Initial block counter is 1, RFC3686 4 */
|
|
be32enc(&ivp[sav->ivlen + 4], 1);
|
|
}
|
|
|
|
m_copyback(m, skip + hlen - sav->ivlen, sav->ivlen, &ivp[4]);
|
|
crde->crd_flags |= CRD_F_IV_EXPLICIT|CRD_F_IV_PRESENT;
|
|
}
|
|
|
|
/* Callback parameters */
|
|
tc->tc_isr = isr;
|
|
KEY_ADDREFSA(sav);
|
|
tc->tc_sav = sav;
|
|
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 | CRYPTO_F_CBIFSYNC;
|
|
crp->crp_buf = (caddr_t) m;
|
|
crp->crp_callback = esp_output_cb;
|
|
crp->crp_opaque = (caddr_t) tc;
|
|
crp->crp_sid = sav->tdb_cryptoid;
|
|
|
|
if (esph) {
|
|
/* Authentication descriptor. */
|
|
crda->crd_alg = esph->type;
|
|
crda->crd_skip = skip;
|
|
if (SAV_ISGCM(sav))
|
|
crda->crd_len = 8; /* RFC4106 5, SPI + SN */
|
|
else
|
|
crda->crd_len = m->m_pkthdr.len - (skip + alen);
|
|
crda->crd_inject = m->m_pkthdr.len - alen;
|
|
}
|
|
|
|
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)
|
|
{
|
|
char buf[INET6_ADDRSTRLEN];
|
|
struct tdb_crypto *tc;
|
|
struct ipsecrequest *isr;
|
|
struct secasvar *sav;
|
|
struct mbuf *m;
|
|
int error;
|
|
|
|
tc = (struct tdb_crypto *) crp->crp_opaque;
|
|
IPSEC_ASSERT(tc != NULL, ("null opaque data area!"));
|
|
m = (struct mbuf *) crp->crp_buf;
|
|
|
|
isr = tc->tc_isr;
|
|
IPSEC_ASSERT(isr->sp != NULL, ("NULL isr->sp"));
|
|
IPSECREQUEST_LOCK(isr);
|
|
sav = tc->tc_sav;
|
|
|
|
/* With the isr lock released, SA pointer may have changed. */
|
|
if (sav != isr->sav) {
|
|
ESPSTAT_INC(esps_notdb);
|
|
DPRINTF(("%s: SA gone during crypto (SA %s/%08lx proto %u)\n",
|
|
__func__, ipsec_address(&tc->tc_dst, buf, sizeof(buf)),
|
|
(u_long) ntohl(tc->tc_spi), tc->tc_proto));
|
|
error = ENOBUFS; /*XXX*/
|
|
goto bad;
|
|
}
|
|
|
|
/* 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) {
|
|
IPSECREQUEST_UNLOCK(isr);
|
|
return (crypto_dispatch(crp));
|
|
}
|
|
|
|
ESPSTAT_INC(esps_noxform);
|
|
DPRINTF(("%s: crypto error %d\n", __func__, crp->crp_etype));
|
|
error = crp->crp_etype;
|
|
goto bad;
|
|
}
|
|
|
|
/* Shouldn't happen... */
|
|
if (m == NULL) {
|
|
ESPSTAT_INC(esps_crypto);
|
|
DPRINTF(("%s: bogus returned buffer from crypto\n", __func__));
|
|
error = EINVAL;
|
|
goto bad;
|
|
}
|
|
ESPSTAT_INC(esps_hist[sav->alg_enc]);
|
|
if (sav->tdb_authalgxform != NULL)
|
|
AHSTAT_INC(ahs_hist[sav->alg_auth]);
|
|
|
|
/* Release crypto descriptors. */
|
|
free(tc, M_XDATA);
|
|
crypto_freereq(crp);
|
|
|
|
#ifdef REGRESSION
|
|
/* Emulate man-in-the-middle attack when ipsec_integrity is TRUE. */
|
|
if (V_ipsec_integrity) {
|
|
static unsigned char ipseczeroes[AH_HMAC_MAXHASHLEN];
|
|
struct auth_hash *esph;
|
|
|
|
/*
|
|
* Corrupt HMAC if we want to test integrity verification of
|
|
* the other side.
|
|
*/
|
|
esph = sav->tdb_authalgxform;
|
|
if (esph != NULL) {
|
|
int alen;
|
|
|
|
alen = xform_ah_authsize(esph);
|
|
m_copyback(m, m->m_pkthdr.len - alen,
|
|
alen, ipseczeroes);
|
|
}
|
|
}
|
|
#endif
|
|
|
|
/* NB: m is reclaimed by ipsec_process_done. */
|
|
error = ipsec_process_done(m, isr);
|
|
KEY_FREESAV(&sav);
|
|
IPSECREQUEST_UNLOCK(isr);
|
|
KEY_FREESP(&isr->sp);
|
|
return (error);
|
|
bad:
|
|
if (sav)
|
|
KEY_FREESAV(&sav);
|
|
IPSECREQUEST_UNLOCK(isr);
|
|
KEY_FREESP(&isr->sp);
|
|
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
|
|
};
|
|
|
|
static void
|
|
esp_attach(void)
|
|
{
|
|
|
|
xform_register(&esp_xformsw);
|
|
}
|
|
SYSINIT(esp_xform_init, SI_SUB_PROTO_DOMAIN, SI_ORDER_MIDDLE, esp_attach, NULL);
|