Based on a patch by ae@. Reviewed by: gbe (man page), pauamma (man page) Sponsored by: Rubicon Communications, LLC ("Netgate") Differential Revision: https://reviews.freebsd.org/D37180
1083 lines
29 KiB
C
1083 lines
29 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 "opt_ipsec.h"
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#include <sys/param.h>
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#include <sys/systm.h>
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#include <sys/malloc.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/mutex.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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#define SPI_SIZE 4
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VNET_DEFINE(int, esp_enable) = 1;
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VNET_DEFINE_STATIC(int, esp_ctr_compatibility) = 1;
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#define V_esp_ctr_compatibility VNET(esp_ctr_compatibility)
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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_INT(_net_inet_esp, OID_AUTO, ctr_compatibility,
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CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(esp_ctr_compatibility), 0,
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"Align AES-CTR encrypted transmitted frames to blocksize");
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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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static MALLOC_DEFINE(M_ESP, "esp", "IPsec ESP");
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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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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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const struct enc_xform *txform;
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struct crypto_session_params csp;
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int keylen;
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int error;
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txform = enc_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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SAV_ISCHACHA(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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if (SAV_ISCTRORGCM(sav) || SAV_ISCHACHA(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->ivsize;
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memset(&csp, 0, sizeof(csp));
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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, &csp);
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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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csp.csp_mode = CSP_MODE_AEAD;
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if (sav->flags & SADB_X_SAFLAGS_ESN)
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csp.csp_flags |= CSP_F_SEPARATE_AAD;
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} else if (sav->alg_enc == SADB_X_EALG_CHACHA20POLY1305) {
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sav->alg_auth = SADB_X_AALG_CHACHA20POLY1305;
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sav->tdb_authalgxform = &auth_hash_poly1305;
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csp.csp_mode = CSP_MODE_AEAD;
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if (sav->flags & SADB_X_SAFLAGS_ESN)
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csp.csp_flags |= CSP_F_SEPARATE_AAD;
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} else if (sav->alg_auth != 0) {
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csp.csp_mode = CSP_MODE_ETA;
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if (sav->flags & SADB_X_SAFLAGS_ESN)
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csp.csp_flags |= CSP_F_ESN;
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} else
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csp.csp_mode = CSP_MODE_CIPHER;
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/* Initialize crypto session. */
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csp.csp_cipher_alg = sav->tdb_encalgxform->type;
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if (csp.csp_cipher_alg != CRYPTO_NULL_CBC) {
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csp.csp_cipher_key = sav->key_enc->key_data;
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csp.csp_cipher_klen = _KEYBITS(sav->key_enc) / 8 -
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SAV_ISCTRORGCM(sav) * 4 - SAV_ISCHACHA(sav) * 4;
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};
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csp.csp_ivlen = txform->ivsize;
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error = crypto_newsession(&sav->tdb_cryptoid, &csp, V_crypto_support);
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return error;
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}
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static void
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esp_cleanup(struct secasvar *sav)
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{
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crypto_freesession(sav->tdb_cryptoid);
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sav->tdb_cryptoid = NULL;
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sav->tdb_authalgxform = NULL;
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sav->tdb_encalgxform = NULL;
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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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IPSEC_DEBUG_DECLARE(char buf[128]);
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const struct auth_hash *esph;
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const struct enc_xform *espx;
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struct xform_data *xd;
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struct cryptop *crp;
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struct newesp *esp;
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uint8_t *ivp;
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crypto_session_t cryptoid;
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int alen, error, hlen, plen;
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uint32_t seqh;
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const struct crypto_session_params *csp;
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SECASVAR_RLOCK_TRACKER;
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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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error = EINVAL;
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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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goto bad;
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}
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if (m->m_len < skip + sizeof(*esp)) {
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m = m_pullup(m, skip + sizeof(*esp));
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if (m == NULL) {
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DPRINTF(("%s: cannot pullup header\n", __func__));
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ESPSTAT_INC(esps_hdrops); /*XXX*/
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error = ENOBUFS;
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goto bad;
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}
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}
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esp = (struct newesp *)(mtod(m, caddr_t) + skip);
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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
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hlen = sizeof (struct newesp) + sav->ivlen;
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alen = xform_ah_authsize(esph);
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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(("%s: payload of %d octets not a multiple of %d octets,"
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" SA %s/%08lx\n", __func__, plen, espx->blocksize,
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ipsec_address(&sav->sah->saidx.dst, buf, sizeof(buf)),
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(u_long)ntohl(sav->spi)));
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ESPSTAT_INC(esps_badilen);
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goto bad;
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}
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/*
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* Check sequence number.
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*/
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SECASVAR_RLOCK(sav);
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if (esph != NULL && sav->replay != NULL && sav->replay->wsize != 0) {
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if (ipsec_chkreplay(ntohl(esp->esp_seq), &seqh, sav) == 0) {
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SECASVAR_RUNLOCK(sav);
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DPRINTF(("%s: packet replay check for %s\n", __func__,
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ipsec_sa2str(sav, buf, sizeof(buf))));
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ESPSTAT_INC(esps_replay);
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error = EACCES;
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goto bad;
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}
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seqh = htonl(seqh);
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}
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cryptoid = sav->tdb_cryptoid;
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SECASVAR_RUNLOCK(sav);
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/* Update the counters */
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ESPSTAT_ADD(esps_ibytes, m->m_pkthdr.len - (skip + hlen + alen));
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/* Get crypto descriptors */
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crp = crypto_getreq(cryptoid, M_NOWAIT);
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if (crp == NULL) {
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DPRINTF(("%s: failed to acquire crypto descriptors\n",
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__func__));
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ESPSTAT_INC(esps_crypto);
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error = ENOBUFS;
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goto bad;
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}
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/* Get IPsec-specific opaque pointer */
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xd = malloc(sizeof(*xd), M_ESP, M_NOWAIT | M_ZERO);
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if (xd == NULL) {
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DPRINTF(("%s: failed to allocate xform_data\n", __func__));
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goto xd_fail;
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}
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if (esph != NULL) {
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crp->crp_op = CRYPTO_OP_VERIFY_DIGEST;
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if (SAV_ISGCM(sav) || SAV_ISCHACHA(sav))
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crp->crp_aad_length = 8; /* RFC4106 5, SPI + SN */
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else
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crp->crp_aad_length = hlen;
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csp = crypto_get_params(crp->crp_session);
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if ((csp->csp_flags & CSP_F_SEPARATE_AAD) &&
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(sav->replay != NULL) && (sav->replay->wsize != 0)) {
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int aad_skip;
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crp->crp_aad_length += sizeof(seqh);
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crp->crp_aad = malloc(crp->crp_aad_length, M_ESP, M_NOWAIT);
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if (crp->crp_aad == NULL) {
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DPRINTF(("%s: failed to allocate xform_data\n",
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__func__));
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goto crp_aad_fail;
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}
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|
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/* SPI */
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m_copydata(m, skip, SPI_SIZE, crp->crp_aad);
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aad_skip = SPI_SIZE;
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|
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/* ESN */
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bcopy(&seqh, (char *)crp->crp_aad + aad_skip, sizeof(seqh));
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aad_skip += sizeof(seqh);
|
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|
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/* Rest of aad */
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if (crp->crp_aad_length - aad_skip > 0)
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m_copydata(m, skip + SPI_SIZE,
|
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crp->crp_aad_length - aad_skip,
|
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(char *)crp->crp_aad + aad_skip);
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} else
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crp->crp_aad_start = skip;
|
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|
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if (csp->csp_flags & CSP_F_ESN &&
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sav->replay != NULL && sav->replay->wsize != 0)
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memcpy(crp->crp_esn, &seqh, sizeof(seqh));
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|
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crp->crp_digest_start = m->m_pkthdr.len - alen;
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}
|
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|
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/* Crypto operation descriptor */
|
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crp->crp_flags = CRYPTO_F_CBIFSYNC;
|
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crypto_use_mbuf(crp, m);
|
|
crp->crp_callback = esp_input_cb;
|
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crp->crp_opaque = xd;
|
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|
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/* These are passed as-is to the callback */
|
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xd->sav = sav;
|
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xd->protoff = protoff;
|
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xd->skip = skip;
|
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xd->cryptoid = cryptoid;
|
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xd->vnet = curvnet;
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|
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/* Decryption descriptor */
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crp->crp_op |= CRYPTO_OP_DECRYPT;
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crp->crp_payload_start = skip + hlen;
|
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crp->crp_payload_length = m->m_pkthdr.len - (skip + hlen + alen);
|
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|
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/* Generate or read cipher IV. */
|
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if (SAV_ISCTRORGCM(sav) || SAV_ISCHACHA(sav)) {
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ivp = &crp->crp_iv[0];
|
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|
|
/*
|
|
* AES-GCM and AES-CTR use similar cipher IV formats
|
|
* defined in RFC 4106 section 4 and RFC 3686 section
|
|
* 4, respectively.
|
|
*
|
|
* The first 4 bytes of the cipher IV contain an
|
|
* implicit salt, or nonce, obtained from the last 4
|
|
* bytes of the encryption key. The next 8 bytes hold
|
|
* an explicit IV unique to each packet. This
|
|
* explicit IV is used as the ESP IV for the packet.
|
|
* The last 4 bytes hold a big-endian block counter
|
|
* incremented for each block. For AES-GCM, the block
|
|
* counter's initial value is defined as part of the
|
|
* algorithm. For AES-CTR, the block counter's
|
|
* initial value for each packet is defined as 1 by
|
|
* RFC 3686.
|
|
*
|
|
* ------------------------------------------
|
|
* | Salt | Explicit ESP IV | Block Counter |
|
|
* ------------------------------------------
|
|
* 4 bytes 8 bytes 4 bytes
|
|
*/
|
|
memcpy(ivp, sav->key_enc->key_data +
|
|
_KEYLEN(sav->key_enc) - 4, 4);
|
|
m_copydata(m, skip + hlen - sav->ivlen, sav->ivlen, &ivp[4]);
|
|
if (SAV_ISCTR(sav)) {
|
|
be32enc(&ivp[sav->ivlen + 4], 1);
|
|
}
|
|
crp->crp_flags |= CRYPTO_F_IV_SEPARATE;
|
|
} else if (sav->ivlen != 0)
|
|
crp->crp_iv_start = skip + hlen - sav->ivlen;
|
|
|
|
if (V_async_crypto)
|
|
return (crypto_dispatch_async(crp, CRYPTO_ASYNC_ORDERED));
|
|
else
|
|
return (crypto_dispatch(crp));
|
|
|
|
crp_aad_fail:
|
|
free(xd, M_ESP);
|
|
xd_fail:
|
|
crypto_freereq(crp);
|
|
ESPSTAT_INC(esps_crypto);
|
|
error = ENOBUFS;
|
|
bad:
|
|
m_freem(m);
|
|
key_freesav(&sav);
|
|
return (error);
|
|
}
|
|
|
|
/*
|
|
* ESP input callback from the crypto driver.
|
|
*/
|
|
static int
|
|
esp_input_cb(struct cryptop *crp)
|
|
{
|
|
IPSEC_DEBUG_DECLARE(char buf[128]);
|
|
uint8_t lastthree[3];
|
|
const struct auth_hash *esph;
|
|
struct mbuf *m;
|
|
struct xform_data *xd;
|
|
struct secasvar *sav;
|
|
struct secasindex *saidx;
|
|
crypto_session_t cryptoid;
|
|
int hlen, skip, protoff, error, alen;
|
|
|
|
SECASVAR_RLOCK_TRACKER;
|
|
|
|
m = crp->crp_buf.cb_mbuf;
|
|
xd = crp->crp_opaque;
|
|
CURVNET_SET(xd->vnet);
|
|
sav = xd->sav;
|
|
skip = xd->skip;
|
|
protoff = xd->protoff;
|
|
cryptoid = xd->cryptoid;
|
|
saidx = &sav->sah->saidx;
|
|
esph = sav->tdb_authalgxform;
|
|
|
|
/* Check for crypto errors */
|
|
if (crp->crp_etype) {
|
|
if (crp->crp_etype == EAGAIN) {
|
|
/* Reset the session ID */
|
|
if (ipsec_updateid(sav, &crp->crp_session, &cryptoid) != 0)
|
|
crypto_freesession(cryptoid);
|
|
xd->cryptoid = crp->crp_session;
|
|
CURVNET_RESTORE();
|
|
return (crypto_dispatch(crp));
|
|
}
|
|
|
|
/* EBADMSG indicates authentication failure. */
|
|
if (!(crp->crp_etype == EBADMSG && esph != NULL)) {
|
|
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]);
|
|
if (crp->crp_etype == EBADMSG) {
|
|
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;
|
|
}
|
|
m->m_flags |= M_AUTHIPDGM;
|
|
/* Remove trailing authenticator */
|
|
m_adj(m, -alen);
|
|
}
|
|
|
|
/* Release the crypto descriptors */
|
|
free(xd, M_ESP), xd = NULL;
|
|
free(crp->crp_aad, M_ESP), crp->crp_aad = 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);
|
|
SECASVAR_RLOCK(sav);
|
|
if (ipsec_updatereplay(ntohl(seq), sav)) {
|
|
SECASVAR_RUNLOCK(sav);
|
|
DPRINTF(("%s: packet replay check for %s\n", __func__,
|
|
ipsec_sa2str(sav, buf, sizeof(buf))));
|
|
ESPSTAT_INC(esps_replay);
|
|
error = EACCES;
|
|
goto bad;
|
|
}
|
|
SECASVAR_RUNLOCK(sav);
|
|
}
|
|
|
|
/* 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;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* RFC4303 2.6:
|
|
* Silently drop packet if next header field is IPPROTO_NONE.
|
|
*/
|
|
if (lastthree[2] == IPPROTO_NONE)
|
|
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);
|
|
}
|
|
CURVNET_RESTORE();
|
|
return error;
|
|
bad:
|
|
if (sav != NULL)
|
|
key_freesav(&sav);
|
|
if (m != NULL)
|
|
m_freem(m);
|
|
if (xd != NULL)
|
|
free(xd, M_ESP);
|
|
if (crp != NULL) {
|
|
free(crp->crp_aad, M_ESP);
|
|
crypto_freereq(crp);
|
|
}
|
|
CURVNET_RESTORE();
|
|
return error;
|
|
}
|
|
/*
|
|
* ESP output routine, called by ipsec[46]_perform_request().
|
|
*/
|
|
static int
|
|
esp_output(struct mbuf *m, struct secpolicy *sp, struct secasvar *sav,
|
|
u_int idx, int skip, int protoff)
|
|
{
|
|
IPSEC_DEBUG_DECLARE(char buf[IPSEC_ADDRSTRLEN]);
|
|
struct cryptop *crp;
|
|
const struct auth_hash *esph;
|
|
const struct enc_xform *espx;
|
|
struct mbuf *mo = NULL;
|
|
struct xform_data *xd;
|
|
struct secasindex *saidx;
|
|
unsigned char *pad;
|
|
uint8_t *ivp;
|
|
uint64_t cntr;
|
|
crypto_session_t cryptoid;
|
|
int hlen, rlen, padding, blks, alen, i, roff;
|
|
int error, maxpacketsize;
|
|
uint8_t prot;
|
|
uint32_t seqh;
|
|
const struct crypto_session_params *csp;
|
|
|
|
SECASVAR_RLOCK_TRACKER;
|
|
|
|
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.
|
|
* Old versions of FreeBSD can't decrypt partial blocks encrypted
|
|
* with AES-CTR. Align payload to native_blocksize (16 bytes)
|
|
* in order to preserve compatibility.
|
|
*/
|
|
if (SAV_ISCTR(sav) && V_esp_ctr_compatibility)
|
|
blks = MAX(4, espx->native_blocksize); /* Cipher blocksize */
|
|
else
|
|
blks = MAX(4, espx->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(uint32_t));
|
|
SECASVAR_RLOCK(sav);
|
|
if (sav->replay) {
|
|
uint32_t replay;
|
|
|
|
SECREPLAY_LOCK(sav->replay);
|
|
#ifdef REGRESSION
|
|
/* Emulate replay attack when ipsec_replay is TRUE. */
|
|
if (!V_ipsec_replay)
|
|
#endif
|
|
sav->replay->count++;
|
|
replay = htonl((uint32_t)sav->replay->count);
|
|
|
|
bcopy((caddr_t) &replay, mtod(mo, caddr_t) + roff +
|
|
sizeof(uint32_t), sizeof(uint32_t));
|
|
|
|
seqh = htonl((uint32_t)(sav->replay->count >> IPSEC_SEQH_SHIFT));
|
|
SECREPLAY_UNLOCK(sav->replay);
|
|
}
|
|
cryptoid = sav->tdb_cryptoid;
|
|
if (SAV_ISCTRORGCM(sav) || SAV_ISCHACHA(sav))
|
|
cntr = sav->cntr++;
|
|
SECASVAR_RUNLOCK(sav);
|
|
|
|
/*
|
|
* 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:
|
|
arc4random_buf(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 descriptor. */
|
|
crp = crypto_getreq(cryptoid, M_NOWAIT);
|
|
if (crp == NULL) {
|
|
DPRINTF(("%s: failed to acquire crypto descriptor\n",
|
|
__func__));
|
|
ESPSTAT_INC(esps_crypto);
|
|
error = ENOBUFS;
|
|
goto bad;
|
|
}
|
|
|
|
/* IPsec-specific opaque crypto info. */
|
|
xd = malloc(sizeof(struct xform_data), M_ESP, M_NOWAIT | M_ZERO);
|
|
if (xd == NULL) {
|
|
DPRINTF(("%s: failed to allocate xform_data\n", __func__));
|
|
goto xd_fail;
|
|
}
|
|
|
|
/* Encryption descriptor. */
|
|
crp->crp_payload_start = skip + hlen;
|
|
crp->crp_payload_length = m->m_pkthdr.len - (skip + hlen + alen);
|
|
crp->crp_op = CRYPTO_OP_ENCRYPT;
|
|
|
|
/* Generate cipher and ESP IVs. */
|
|
ivp = &crp->crp_iv[0];
|
|
if (SAV_ISCTRORGCM(sav) || SAV_ISCHACHA(sav)) {
|
|
/*
|
|
* See comment in esp_input() for details on the
|
|
* cipher IV. A simple per-SA counter stored in
|
|
* 'cntr' is used as the explicit ESP IV.
|
|
*/
|
|
memcpy(ivp, sav->key_enc->key_data +
|
|
_KEYLEN(sav->key_enc) - 4, 4);
|
|
be64enc(&ivp[4], cntr);
|
|
if (SAV_ISCTR(sav)) {
|
|
be32enc(&ivp[sav->ivlen + 4], 1);
|
|
}
|
|
m_copyback(m, skip + hlen - sav->ivlen, sav->ivlen, &ivp[4]);
|
|
crp->crp_flags |= CRYPTO_F_IV_SEPARATE;
|
|
} else if (sav->ivlen != 0) {
|
|
arc4rand(ivp, sav->ivlen, 0);
|
|
crp->crp_iv_start = skip + hlen - sav->ivlen;
|
|
m_copyback(m, crp->crp_iv_start, sav->ivlen, ivp);
|
|
}
|
|
|
|
/* Callback parameters */
|
|
xd->sp = sp;
|
|
xd->sav = sav;
|
|
xd->idx = idx;
|
|
xd->cryptoid = cryptoid;
|
|
xd->vnet = curvnet;
|
|
|
|
/* Crypto operation descriptor. */
|
|
crp->crp_flags |= CRYPTO_F_CBIFSYNC;
|
|
crypto_use_mbuf(crp, m);
|
|
crp->crp_callback = esp_output_cb;
|
|
crp->crp_opaque = xd;
|
|
|
|
if (esph) {
|
|
/* Authentication descriptor. */
|
|
crp->crp_op |= CRYPTO_OP_COMPUTE_DIGEST;
|
|
if (SAV_ISGCM(sav) || SAV_ISCHACHA(sav))
|
|
crp->crp_aad_length = 8; /* RFC4106 5, SPI + SN */
|
|
else
|
|
crp->crp_aad_length = hlen;
|
|
|
|
csp = crypto_get_params(crp->crp_session);
|
|
if (csp->csp_flags & CSP_F_SEPARATE_AAD &&
|
|
sav->replay != NULL) {
|
|
int aad_skip;
|
|
|
|
crp->crp_aad_length += sizeof(seqh);
|
|
crp->crp_aad = malloc(crp->crp_aad_length, M_ESP, M_NOWAIT);
|
|
if (crp->crp_aad == NULL) {
|
|
DPRINTF(("%s: failed to allocate xform_data\n",
|
|
__func__));
|
|
goto crp_aad_fail;
|
|
}
|
|
|
|
/* SPI */
|
|
m_copydata(m, skip, SPI_SIZE, crp->crp_aad);
|
|
aad_skip = SPI_SIZE;
|
|
|
|
/* ESN */
|
|
bcopy(&seqh, (char *)crp->crp_aad + aad_skip, sizeof(seqh));
|
|
aad_skip += sizeof(seqh);
|
|
|
|
/* Rest of aad */
|
|
if (crp->crp_aad_length - aad_skip > 0)
|
|
m_copydata(m, skip + SPI_SIZE,
|
|
crp->crp_aad_length - aad_skip,
|
|
(char *)crp->crp_aad + aad_skip);
|
|
} else
|
|
crp->crp_aad_start = skip;
|
|
|
|
if (csp->csp_flags & CSP_F_ESN && sav->replay != NULL)
|
|
memcpy(crp->crp_esn, &seqh, sizeof(seqh));
|
|
|
|
crp->crp_digest_start = m->m_pkthdr.len - alen;
|
|
}
|
|
|
|
if (V_async_crypto)
|
|
return (crypto_dispatch_async(crp, CRYPTO_ASYNC_ORDERED));
|
|
else
|
|
return (crypto_dispatch(crp));
|
|
|
|
crp_aad_fail:
|
|
free(xd, M_ESP);
|
|
xd_fail:
|
|
crypto_freereq(crp);
|
|
ESPSTAT_INC(esps_crypto);
|
|
error = ENOBUFS;
|
|
bad:
|
|
if (m)
|
|
m_freem(m);
|
|
key_freesav(&sav);
|
|
key_freesp(&sp);
|
|
return (error);
|
|
}
|
|
/*
|
|
* ESP output callback from the crypto driver.
|
|
*/
|
|
static int
|
|
esp_output_cb(struct cryptop *crp)
|
|
{
|
|
struct xform_data *xd;
|
|
struct secpolicy *sp;
|
|
struct secasvar *sav;
|
|
struct mbuf *m;
|
|
crypto_session_t cryptoid;
|
|
u_int idx;
|
|
int error;
|
|
|
|
xd = (struct xform_data *) crp->crp_opaque;
|
|
CURVNET_SET(xd->vnet);
|
|
m = crp->crp_buf.cb_mbuf;
|
|
sp = xd->sp;
|
|
sav = xd->sav;
|
|
idx = xd->idx;
|
|
cryptoid = xd->cryptoid;
|
|
|
|
/* Check for crypto errors. */
|
|
if (crp->crp_etype) {
|
|
if (crp->crp_etype == EAGAIN) {
|
|
/* Reset the session ID */
|
|
if (ipsec_updateid(sav, &crp->crp_session, &cryptoid) != 0)
|
|
crypto_freesession(cryptoid);
|
|
xd->cryptoid = crp->crp_session;
|
|
CURVNET_RESTORE();
|
|
return (crypto_dispatch(crp));
|
|
}
|
|
ESPSTAT_INC(esps_noxform);
|
|
DPRINTF(("%s: crypto error %d\n", __func__, crp->crp_etype));
|
|
error = crp->crp_etype;
|
|
m_freem(m);
|
|
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;
|
|
}
|
|
free(xd, M_ESP);
|
|
free(crp->crp_aad, M_ESP);
|
|
crypto_freereq(crp);
|
|
ESPSTAT_INC(esps_hist[sav->alg_enc]);
|
|
if (sav->tdb_authalgxform != NULL)
|
|
AHSTAT_INC(ahs_hist[sav->alg_auth]);
|
|
|
|
#ifdef REGRESSION
|
|
/* Emulate man-in-the-middle attack when ipsec_integrity is TRUE. */
|
|
if (V_ipsec_integrity) {
|
|
static unsigned char ipseczeroes[AH_HMAC_MAXHASHLEN];
|
|
const 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, sp, sav, idx);
|
|
CURVNET_RESTORE();
|
|
return (error);
|
|
bad:
|
|
free(xd, M_ESP);
|
|
free(crp->crp_aad, M_ESP);
|
|
crypto_freereq(crp);
|
|
key_freesav(&sav);
|
|
key_freesp(&sp);
|
|
CURVNET_RESTORE();
|
|
return (error);
|
|
}
|
|
|
|
static struct xformsw esp_xformsw = {
|
|
.xf_type = XF_ESP,
|
|
.xf_name = "IPsec ESP",
|
|
.xf_init = esp_init,
|
|
.xf_cleanup = esp_cleanup,
|
|
.xf_input = esp_input,
|
|
.xf_output = esp_output,
|
|
};
|
|
|
|
SYSINIT(esp_xform_init, SI_SUB_PROTO_DOMAIN, SI_ORDER_MIDDLE,
|
|
xform_attach, &esp_xformsw);
|
|
SYSUNINIT(esp_xform_uninit, SI_SUB_PROTO_DOMAIN, SI_ORDER_MIDDLE,
|
|
xform_detach, &esp_xformsw);
|