NetBSD-5.0.2/sys/netipsec/xform_ah.c
/* $NetBSD: xform_ah.c,v 1.21 2008/04/23 06:09:05 thorpej Exp $ */
/* $FreeBSD: src/sys/netipsec/xform_ah.c,v 1.1.4.1 2003/01/24 05:11:36 sam Exp $ */
/* $OpenBSD: ip_ah.c,v 1.63 2001/06/26 06:18:58 angelos Exp $ */
/*
* The authors of this code are John Ioannidis (ji@tla.org),
* Angelos D. Keromytis (kermit@csd.uch.gr) and
* Niels Provos (provos@physnet.uni-hamburg.de).
*
* The original version of this code was written by John Ioannidis
* for BSD/OS in Athens, Greece, in November 1995.
*
* Ported to OpenBSD and NetBSD, with additional transforms, in December 1996,
* by Angelos D. Keromytis.
*
* Additional transforms and features in 1997 and 1998 by Angelos D. Keromytis
* and Niels Provos.
*
* Additional features in 1999 by Angelos D. Keromytis and Niklas Hallqvist.
*
* Copyright (c) 1995, 1996, 1997, 1998, 1999 by John Ioannidis,
* Angelos D. Keromytis and Niels Provos.
* Copyright (c) 1999 Niklas Hallqvist.
* Copyright (c) 2001 Angelos D. Keromytis.
*
* Permission to use, copy, and modify this software with or without fee
* is hereby granted, provided that this entire notice is included in
* all copies of any software which is or includes a copy or
* modification of this software.
* You may use this code under the GNU public license if you so wish. Please
* contribute changes back to the authors under this freer than GPL license
* so that we may further the use of strong encryption without limitations to
* all.
*
* THIS SOFTWARE IS BEING PROVIDED "AS IS", WITHOUT ANY EXPRESS OR
* IMPLIED WARRANTY. IN PARTICULAR, NONE OF THE AUTHORS MAKES ANY
* REPRESENTATION OR WARRANTY OF ANY KIND CONCERNING THE
* MERCHANTABILITY OF THIS SOFTWARE OR ITS FITNESS FOR ANY PARTICULAR
* PURPOSE.
*/
#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: xform_ah.c,v 1.21 2008/04/23 06:09:05 thorpej Exp $");
#include "opt_inet.h"
#ifdef __FreeBSD__
#include "opt_inet6.h"
#endif
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/mbuf.h>
#include <sys/socket.h>
#include <sys/syslog.h>
#include <sys/kernel.h>
#include <sys/sysctl.h>
#include <net/if.h>
#include <netinet/in.h>
#include <netinet/in_systm.h>
#include <netinet/ip.h>
#include <netinet/ip_ecn.h>
#include <netinet/ip6.h>
#include <net/route.h>
#include <netipsec/ipsec.h>
#include <netipsec/ipsec_private.h>
#include <netipsec/ah.h>
#include <netipsec/ah_var.h>
#include <netipsec/xform.h>
#ifdef INET6
#include <netinet6/ip6_var.h>
#include <netipsec/ipsec6.h>
# ifdef __FreeBSD__
# include <netinet6/ip6_ecn.h>
# endif
#endif
#include <netipsec/key.h>
#include <netipsec/key_debug.h>
#include <netipsec/ipsec_osdep.h>
#include <opencrypto/cryptodev.h>
/*
* Return header size in bytes. The old protocol did not support
* the replay counter; the new protocol always includes the counter.
*/
#define HDRSIZE(sav) \
(((sav)->flags & SADB_X_EXT_OLD) ? \
sizeof (struct ah) : sizeof (struct ah) + sizeof (u_int32_t))
/*
* Return authenticator size in bytes. The old protocol is known
* to use a fixed 16-byte authenticator. The new algorithm gets
* this size from the xform but is (currently) always 12.
*/
#define AUTHSIZE(sav) \
((sav->flags & SADB_X_EXT_OLD) ? 16 : (sav)->tdb_authalgxform->authsize)
percpu_t *ahstat_percpu;
int ah_enable = 1; /* control flow of packets with AH */
int ip4_ah_cleartos = 1; /* clear ip_tos when doing AH calc */
#ifdef __FreeBSD__
SYSCTL_DECL(_net_inet_ah);
SYSCTL_INT(_net_inet_ah, OID_AUTO,
ah_enable, CTLFLAG_RW, &ah_enable, 0, "");
SYSCTL_INT(_net_inet_ah, OID_AUTO,
ah_cleartos, CTLFLAG_RW, &ip4_ah_cleartos, 0, "");
SYSCTL_STRUCT(_net_inet_ah, IPSECCTL_STATS,
stats, CTLFLAG_RD, &ahstat, ahstat, "");
#endif /* __FreeBSD__ */
static unsigned char ipseczeroes[256]; /* larger than an ip6 extension hdr */
static int ah_input_cb(struct cryptop*);
static int ah_output_cb(struct cryptop*);
/*
* NB: this is public for use by the PF_KEY support.
*/
struct auth_hash *
ah_algorithm_lookup(int alg)
{
if (alg >= AH_ALG_MAX)
return NULL;
switch (alg) {
case SADB_X_AALG_NULL:
return &auth_hash_null;
case SADB_AALG_MD5HMAC:
return &auth_hash_hmac_md5_96;
case SADB_AALG_SHA1HMAC:
return &auth_hash_hmac_sha1_96;
case SADB_X_AALG_RIPEMD160HMAC:
return &auth_hash_hmac_ripemd_160_96;
case SADB_X_AALG_MD5:
return &auth_hash_key_md5;
case SADB_X_AALG_SHA:
return &auth_hash_key_sha1;
case SADB_X_AALG_SHA2_256:
return &auth_hash_hmac_sha2_256;
case SADB_X_AALG_SHA2_384:
return &auth_hash_hmac_sha2_384;
case SADB_X_AALG_SHA2_512:
return &auth_hash_hmac_sha2_512;
}
return NULL;
}
size_t
ah_hdrsiz(struct secasvar *sav)
{
size_t size;
if (sav != NULL) {
int authsize;
IPSEC_ASSERT(sav->tdb_authalgxform != NULL,
("ah_hdrsiz: null xform"));
/*XXX not right for null algorithm--does it matter??*/
authsize = AUTHSIZE(sav);
size = roundup(authsize, sizeof (u_int32_t)) + HDRSIZE(sav);
} else {
/* default guess */
size = sizeof (struct ah) + sizeof (u_int32_t) + 16;
}
return size;
}
/*
* NB: public for use by esp_init.
*/
int
ah_init0(struct secasvar *sav, struct xformsw *xsp, struct cryptoini *cria)
{
struct auth_hash *thash;
int keylen;
thash = ah_algorithm_lookup(sav->alg_auth);
if (thash == NULL) {
DPRINTF(("ah_init: unsupported authentication algorithm %u\n",
sav->alg_auth));
return EINVAL;
}
/*
* Verify the replay state block allocation is consistent with
* the protocol type. We check here so we can make assumptions
* later during protocol processing.
*/
/* NB: replay state is setup elsewhere (sigh) */
if (((sav->flags&SADB_X_EXT_OLD) == 0) ^ (sav->replay != NULL)) {
DPRINTF(("ah_init: replay state block inconsistency, "
"%s algorithm %s replay state\n",
(sav->flags & SADB_X_EXT_OLD) ? "old" : "new",
sav->replay == NULL ? "without" : "with"));
return EINVAL;
}
if (sav->key_auth == NULL) {
DPRINTF(("ah_init: no authentication key for %s "
"algorithm\n", thash->name));
return EINVAL;
}
keylen = _KEYLEN(sav->key_auth);
if (keylen != thash->keysize && thash->keysize != 0) {
DPRINTF(("ah_init: invalid keylength %d, algorithm "
"%s requires keysize %d\n",
keylen, thash->name, thash->keysize));
return EINVAL;
}
sav->tdb_xform = xsp;
sav->tdb_authalgxform = thash;
/* Initialize crypto session. */
bzero(cria, sizeof (*cria));
cria->cri_alg = sav->tdb_authalgxform->type;
cria->cri_klen = _KEYBITS(sav->key_auth);
cria->cri_key = _KEYBUF(sav->key_auth);
return 0;
}
/*
* ah_init() is called when an SPI is being set up.
*/
static int
ah_init(struct secasvar *sav, struct xformsw *xsp)
{
struct cryptoini cria;
int error;
error = ah_init0(sav, xsp, &cria);
if (!error) {
mutex_spin_enter(&crypto_mtx);
error = crypto_newsession(&sav->tdb_cryptoid,
&cria, crypto_support);
mutex_spin_exit(&crypto_mtx);
}
return error;
}
/*
* Paranoia.
*
* NB: public for use by esp_zeroize (XXX).
*/
int
ah_zeroize(struct secasvar *sav)
{
int err;
if (sav->key_auth)
bzero(_KEYBUF(sav->key_auth), _KEYLEN(sav->key_auth));
mutex_spin_enter(&crypto_mtx);
err = crypto_freesession(sav->tdb_cryptoid);
mutex_spin_exit(&crypto_mtx);
sav->tdb_cryptoid = 0;
sav->tdb_authalgxform = NULL;
sav->tdb_xform = NULL;
return err;
}
/*
* Massage IPv4/IPv6 headers for AH processing.
*/
static int
ah_massage_headers(struct mbuf **m0, int proto, int skip, int alg, int out)
{
struct mbuf *m = *m0;
unsigned char *ptr;
int off, count;
#ifdef INET
struct ip *ip;
#endif /* INET */
#ifdef INET6
struct ip6_ext *ip6e;
struct ip6_hdr ip6;
int alloc, len, ad;
#endif /* INET6 */
switch (proto) {
#ifdef INET
case AF_INET:
/*
* This is the least painful way of dealing with IPv4 header
* and option processing -- just make sure they're in
* contiguous memory.
*/
*m0 = m = m_pullup(m, skip);
if (m == NULL) {
DPRINTF(("ah_massage_headers: m_pullup failed\n"));
return ENOBUFS;
}
/* Fix the IP header */
ip = mtod(m, struct ip *);
if (ip4_ah_cleartos)
ip->ip_tos = 0;
ip->ip_ttl = 0;
ip->ip_sum = 0;
ip->ip_off = htons(ntohs(ip->ip_off) & ip4_ah_offsetmask);
/*
* On FreeBSD, ip_off and ip_len assumed in host endian;
* they are converted (if necessary) by ip_input().
* On NetBSD, ip_off and ip_len are in network byte order.
* They must be massaged back to network byte order
* before verifying the HMAC. Moreover, on FreeBSD,
* we should add `skip' back into the massaged ip_len
* (presumably ip_input() deducted it before we got here?)
* whereas on NetBSD, we should not.
*/
#ifdef __FreeBSD__
#define TOHOST(x) (x)
#else
#define TOHOST(x) (ntohs(x))
#endif
if (!out) {
u_int16_t inlen = TOHOST(ip->ip_len);
#ifdef __FreeBSD__
ip->ip_len = htons(inlen + skip);
#else /*!__FreeBSD__ */
ip->ip_len = htons(inlen);
#endif /*!__FreeBSD__ */
DPRINTF(("ip len: skip %d, "
"in %d host %d: new: raw %d host %d\n",
skip,
inlen, TOHOST(inlen),
ip->ip_len, ntohs(ip->ip_len)));
if (alg == CRYPTO_MD5_KPDK || alg == CRYPTO_SHA1_KPDK)
ip->ip_off &= IP_OFF_CONVERT(IP_DF);
else
ip->ip_off = 0;
} else {
if (alg == CRYPTO_MD5_KPDK || alg == CRYPTO_SHA1_KPDK)
ip->ip_off &= IP_OFF_CONVERT(IP_DF);
else
ip->ip_off = 0;
}
ptr = mtod(m, unsigned char *) + sizeof(struct ip);
/* IPv4 option processing */
for (off = sizeof(struct ip); off < skip;) {
if (ptr[off] == IPOPT_EOL || ptr[off] == IPOPT_NOP ||
off + 1 < skip)
;
else {
DPRINTF(("ah_massage_headers: illegal IPv4 "
"option length for option %d\n",
ptr[off]));
m_freem(m);
return EINVAL;
}
switch (ptr[off]) {
case IPOPT_EOL:
off = skip; /* End the loop. */
break;
case IPOPT_NOP:
off++;
break;
case IPOPT_SECURITY: /* 0x82 */
case 0x85: /* Extended security. */
case 0x86: /* Commercial security. */
case 0x94: /* Router alert */
case 0x95: /* RFC1770 */
/* Sanity check for option length. */
if (ptr[off + 1] < 2) {
DPRINTF(("ah_massage_headers: "
"illegal IPv4 option length for "
"option %d\n", ptr[off]));
m_freem(m);
return EINVAL;
}
off += ptr[off + 1];
break;
case IPOPT_LSRR:
case IPOPT_SSRR:
/* Sanity check for option length. */
if (ptr[off + 1] < 2) {
DPRINTF(("ah_massage_headers: "
"illegal IPv4 option length for "
"option %d\n", ptr[off]));
m_freem(m);
return EINVAL;
}
/*
* On output, if we have either of the
* source routing options, we should
* swap the destination address of the
* IP header with the last address
* specified in the option, as that is
* what the destination's IP header
* will look like.
*/
if (out)
bcopy(ptr + off + ptr[off + 1] -
sizeof(struct in_addr),
&(ip->ip_dst), sizeof(struct in_addr));
/* Fall through */
default:
/* Sanity check for option length. */
if (ptr[off + 1] < 2) {
DPRINTF(("ah_massage_headers: "
"illegal IPv4 option length for "
"option %d\n", ptr[off]));
m_freem(m);
return EINVAL;
}
/* Zeroize all other options. */
count = ptr[off + 1];
bcopy(ipseczeroes, ptr, count);
off += count;
break;
}
/* Sanity check. */
if (off > skip) {
DPRINTF(("ah_massage_headers(): malformed "
"IPv4 options header\n"));
m_freem(m);
return EINVAL;
}
}
break;
#endif /* INET */
#ifdef INET6
case AF_INET6: /* Ugly... */
/* Copy and "cook" the IPv6 header. */
m_copydata(m, 0, sizeof(ip6), &ip6);
/* We don't do IPv6 Jumbograms. */
if (ip6.ip6_plen == 0) {
DPRINTF(("ah_massage_headers: unsupported IPv6 jumbogram\n"));
m_freem(m);
return EMSGSIZE;
}
ip6.ip6_flow = 0;
ip6.ip6_hlim = 0;
ip6.ip6_vfc &= ~IPV6_VERSION_MASK;
ip6.ip6_vfc |= IPV6_VERSION;
/* Scoped address handling. */
if (IN6_IS_SCOPE_LINKLOCAL(&ip6.ip6_src))
ip6.ip6_src.s6_addr16[1] = 0;
if (IN6_IS_SCOPE_LINKLOCAL(&ip6.ip6_dst))
ip6.ip6_dst.s6_addr16[1] = 0;
/* Done with IPv6 header. */
m_copyback(m, 0, sizeof(struct ip6_hdr), &ip6);
/* Let's deal with the remaining headers (if any). */
if (skip - sizeof(struct ip6_hdr) > 0) {
if (m->m_len <= skip) {
ptr = (unsigned char *) malloc(
skip - sizeof(struct ip6_hdr),
M_XDATA, M_NOWAIT);
if (ptr == NULL) {
DPRINTF(("ah_massage_headers: failed "
"to allocate memory for IPv6 "
"headers\n"));
m_freem(m);
return ENOBUFS;
}
/*
* Copy all the protocol headers after
* the IPv6 header.
*/
m_copydata(m, sizeof(struct ip6_hdr),
skip - sizeof(struct ip6_hdr), ptr);
alloc = 1;
} else {
/* No need to allocate memory. */
ptr = mtod(m, unsigned char *) +
sizeof(struct ip6_hdr);
alloc = 0;
}
} else
break;
off = ip6.ip6_nxt & 0xff; /* Next header type. */
for (len = 0; len < skip - sizeof(struct ip6_hdr);)
switch (off) {
case IPPROTO_HOPOPTS:
case IPPROTO_DSTOPTS:
ip6e = (struct ip6_ext *) (ptr + len);
/*
* Process the mutable/immutable
* options -- borrows heavily from the
* KAME code.
*/
for (count = len + sizeof(struct ip6_ext);
count < len + ((ip6e->ip6e_len + 1) << 3);) {
if (ptr[count] == IP6OPT_PAD1) {
count++;
continue; /* Skip padding. */
}
/* Sanity check. */
if (count > len +
((ip6e->ip6e_len + 1) << 3)) {
m_freem(m);
/* Free, if we allocated. */
if (alloc)
FREE(ptr, M_XDATA);
return EINVAL;
}
ad = ptr[count + 1];
/* If mutable option, zeroize. */
if (ptr[count] & IP6OPT_MUTABLE)
bcopy(ipseczeroes, ptr + count,
ptr[count + 1]);
count += ad;
/* Sanity check. */
if (count >
skip - sizeof(struct ip6_hdr)) {
m_freem(m);
/* Free, if we allocated. */
if (alloc)
FREE(ptr, M_XDATA);
return EINVAL;
}
}
/* Advance. */
len += ((ip6e->ip6e_len + 1) << 3);
off = ip6e->ip6e_nxt;
break;
case IPPROTO_ROUTING:
/*
* Always include routing headers in
* computation.
*/
ip6e = (struct ip6_ext *) (ptr + len);
len += ((ip6e->ip6e_len + 1) << 3);
off = ip6e->ip6e_nxt;
break;
default:
DPRINTF(("ah_massage_headers: unexpected "
"IPv6 header type %d", off));
if (alloc)
FREE(ptr, M_XDATA);
m_freem(m);
return EINVAL;
}
/* Copyback and free, if we allocated. */
if (alloc) {
m_copyback(m, sizeof(struct ip6_hdr),
skip - sizeof(struct ip6_hdr), ptr);
free(ptr, M_XDATA);
}
break;
#endif /* INET6 */
}
return 0;
}
/*
* ah_input() gets called to verify that an input packet
* passes authentication.
*/
static int
ah_input(struct mbuf *m, struct secasvar *sav, int skip, int protoff)
{
struct auth_hash *ahx;
struct tdb_ident *tdbi;
struct tdb_crypto *tc;
struct m_tag *mtag;
struct newah *ah;
int hl, rplen, authsize;
struct cryptodesc *crda;
struct cryptop *crp;
IPSEC_SPLASSERT_SOFTNET("ah_input");
IPSEC_ASSERT(sav != NULL, ("ah_input: null SA"));
IPSEC_ASSERT(sav->key_auth != NULL,
("ah_input: null authentication key"));
IPSEC_ASSERT(sav->tdb_authalgxform != NULL,
("ah_input: null authentication xform"));
/* Figure out header size. */
rplen = HDRSIZE(sav);
/* XXX don't pullup, just copy header */
IP6_EXTHDR_GET(ah, struct newah *, m, skip, rplen);
if (ah == NULL) {
DPRINTF(("ah_input: cannot pullup header\n"));
AH_STATINC(AH_STAT_HDROPS); /*XXX*/
m_freem(m);
return ENOBUFS;
}
/* Check replay window, if applicable. */
if (sav->replay && !ipsec_chkreplay(ntohl(ah->ah_seq), sav)) {
AH_STATINC(AH_STAT_REPLAY);
DPRINTF(("ah_input: packet replay failure: %s\n",
ipsec_logsastr(sav)));
m_freem(m);
return ENOBUFS;
}
/* Verify AH header length. */
hl = ah->ah_len * sizeof (u_int32_t);
ahx = sav->tdb_authalgxform;
authsize = AUTHSIZE(sav);
if (hl != authsize + rplen - sizeof (struct ah)) {
DPRINTF(("ah_input: bad authenticator length %u (expecting %lu)"
" for packet in SA %s/%08lx\n",
hl, (u_long) (authsize + rplen - sizeof (struct ah)),
ipsec_address(&sav->sah->saidx.dst),
(u_long) ntohl(sav->spi)));
AH_STATINC(AH_STAT_BADAUTHL);
m_freem(m);
return EACCES;
}
AH_STATADD(AH_STAT_IBYTES, m->m_pkthdr.len - skip - hl);
DPRINTF(("ah_input skip %d poff %d\n"
"len: hl %d authsize %d rpl %d expect %ld\n",
skip, protoff,
hl, authsize, rplen,
(long)(authsize + rplen - sizeof(struct ah))));
/* Get crypto descriptors. */
crp = crypto_getreq(1);
if (crp == NULL) {
DPRINTF(("ah_input: failed to acquire crypto descriptor\n"));
AH_STATINC(AH_STAT_CRYPTO);
m_freem(m);
return ENOBUFS;
}
crda = crp->crp_desc;
IPSEC_ASSERT(crda != NULL, ("ah_input: null crypto descriptor"));
crda->crd_skip = 0;
crda->crd_len = m->m_pkthdr.len;
crda->crd_inject = skip + rplen;
/* Authentication operation. */
crda->crd_alg = ahx->type;
crda->crd_key = _KEYBUF(sav->key_auth);
crda->crd_klen = _KEYBITS(sav->key_auth);
/* Find out if we've already done crypto. */
for (mtag = m_tag_find(m, PACKET_TAG_IPSEC_IN_CRYPTO_DONE, NULL);
mtag != NULL;
mtag = m_tag_find(m, PACKET_TAG_IPSEC_IN_CRYPTO_DONE, mtag)) {
tdbi = (struct tdb_ident *) (mtag + 1);
if (tdbi->proto == sav->sah->saidx.proto &&
tdbi->spi == sav->spi &&
!bcmp(&tdbi->dst, &sav->sah->saidx.dst,
sizeof (union sockaddr_union)))
break;
}
/* Allocate IPsec-specific opaque crypto info. */
if (mtag == NULL) {
tc = (struct tdb_crypto *) malloc(sizeof (struct tdb_crypto) +
skip + rplen + authsize, M_XDATA, M_NOWAIT|M_ZERO);
} else {
/* Hash verification has already been done successfully. */
tc = (struct tdb_crypto *) malloc(sizeof (struct tdb_crypto),
M_XDATA, M_NOWAIT|M_ZERO);
}
if (tc == NULL) {
DPRINTF(("ah_input: failed to allocate tdb_crypto\n"));
AH_STATINC(AH_STAT_CRYPTO);
crypto_freereq(crp);
m_freem(m);
return ENOBUFS;
}
/* Only save information if crypto processing is needed. */
if (mtag == NULL) {
int error;
/*
* Save the authenticator, the skipped portion of the packet,
* and the AH header.
*/
m_copydata(m, 0, skip + rplen + authsize, (char *)(tc+1));
{
u_int8_t *pppp = ((char *)(tc+1))+skip+rplen;
DPRINTF(("ah_input: zeroing %d bytes of authent " \
"%02x%02x:%02x%02x:%02x%02x:%02x%02x:%02x%02x:%02x%02x\n",
authsize,
pppp[0], pppp[1], pppp[2], pppp[3],
pppp[4], pppp[5], pppp[6], pppp[7],
pppp[8], pppp[9], pppp[10], pppp[11]));
}
/* Zeroize the authenticator on the packet. */
m_copyback(m, skip + rplen, authsize, ipseczeroes);
/* "Massage" the packet headers for crypto processing. */
error = ah_massage_headers(&m, sav->sah->saidx.dst.sa.sa_family,
skip, ahx->type, 0);
if (error != 0) {
/* NB: mbuf is free'd by ah_massage_headers */
AH_STATINC(AH_STAT_HDROPS);
free(tc, M_XDATA);
crypto_freereq(crp);
return error;
}
}
/* Crypto operation descriptor. */
crp->crp_ilen = m->m_pkthdr.len; /* Total input length. */
crp->crp_flags = CRYPTO_F_IMBUF;
crp->crp_buf = m;
crp->crp_callback = ah_input_cb;
crp->crp_sid = sav->tdb_cryptoid;
crp->crp_opaque = 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_nxt = ah->ah_nxt;
tc->tc_protoff = protoff;
tc->tc_skip = skip;
tc->tc_ptr = mtag; /* Save the mtag we've identified. */
DPRINTF(("ah: hash over %d bytes, skip %d: "
"crda len %d skip %d inject %d\n",
crp->crp_ilen, tc->tc_skip,
crda->crd_len, crda->crd_skip, crda->crd_inject));
if (mtag == NULL)
return crypto_dispatch(crp);
else
return ah_input_cb(crp);
}
#ifdef INET6
#define IPSEC_COMMON_INPUT_CB(m, sav, skip, protoff, mtag) do { \
if (saidx->dst.sa.sa_family == AF_INET6) { \
error = ipsec6_common_input_cb(m, sav, skip, protoff, mtag); \
} else { \
error = ipsec4_common_input_cb(m, sav, skip, protoff, mtag); \
} \
} while (0)
#else
#define IPSEC_COMMON_INPUT_CB(m, sav, skip, protoff, mtag) \
(error = ipsec4_common_input_cb(m, sav, skip, protoff, mtag))
#endif
/*
* AH input callback from the crypto driver.
*/
static int
ah_input_cb(struct cryptop *crp)
{
int rplen, error, skip, protoff;
unsigned char calc[AH_ALEN_MAX];
struct mbuf *m;
struct cryptodesc *crd;
struct auth_hash *ahx;
struct tdb_crypto *tc;
struct m_tag *mtag;
struct secasvar *sav;
struct secasindex *saidx;
u_int8_t nxt;
char *ptr;
int s, authsize;
u_int16_t dport = 0;
u_int16_t sport = 0;
#ifdef IPSEC_NAT_T
struct m_tag * tag = NULL;
#endif
crd = crp->crp_desc;
tc = (struct tdb_crypto *) crp->crp_opaque;
IPSEC_ASSERT(tc != NULL, ("ah_input_cb: null opaque crypto data area!"));
skip = tc->tc_skip;
nxt = tc->tc_nxt;
protoff = tc->tc_protoff;
mtag = (struct m_tag *) tc->tc_ptr;
m = (struct mbuf *) crp->crp_buf;
#ifdef IPSEC_NAT_T
/* find the source port for NAT-T */
if ((tag = m_tag_find(m, PACKET_TAG_IPSEC_NAT_T_PORTS, NULL))) {
sport = ((u_int16_t *)(tag + 1))[0];
dport = ((u_int16_t *)(tag + 1))[1];
}
#endif
s = splsoftnet();
sav = KEY_ALLOCSA(&tc->tc_dst, tc->tc_proto, tc->tc_spi, sport, dport);
if (sav == NULL) {
AH_STATINC(AH_STAT_NOTDB);
DPRINTF(("ah_input_cb: SA expired while in crypto\n"));
error = ENOBUFS; /*XXX*/
goto bad;
}
saidx = &sav->sah->saidx;
IPSEC_ASSERT(saidx->dst.sa.sa_family == AF_INET ||
saidx->dst.sa.sa_family == AF_INET6,
("ah_input_cb: unexpected protocol family %u",
saidx->dst.sa.sa_family));
ahx = (struct auth_hash *) sav->tdb_authalgxform;
/* Check for crypto errors. */
if (crp->crp_etype) {
if (sav->tdb_cryptoid != 0)
sav->tdb_cryptoid = crp->crp_sid;
if (crp->crp_etype == EAGAIN)
return crypto_dispatch(crp);
AH_STATINC(AH_STAT_NOXFORM);
DPRINTF(("ah_input_cb: crypto error %d\n", crp->crp_etype));
error = crp->crp_etype;
goto bad;
} else {
AH_STATINC(AH_STAT_HIST + sav->alg_auth);
crypto_freereq(crp); /* No longer needed. */
crp = NULL;
}
/* Shouldn't happen... */
if (m == NULL) {
AH_STATINC(AH_STAT_CRYPTO);
DPRINTF(("ah_input_cb: bogus returned buffer from crypto\n"));
error = EINVAL;
goto bad;
}
/* Figure out header size. */
rplen = HDRSIZE(sav);
authsize = AUTHSIZE(sav);
if (ipsec_debug)
bzero(calc, sizeof(calc));
/* Copy authenticator off the packet. */
m_copydata(m, skip + rplen, authsize, calc);
/*
* If we have an mtag, we don't need to verify the authenticator --
* it has been verified by an IPsec-aware NIC.
*/
if (mtag == NULL) {
ptr = (char *) (tc + 1);
/* Verify authenticator. */
if (bcmp(ptr + skip + rplen, calc, authsize)) {
u_int8_t *pppp = ptr + skip+rplen;
DPRINTF(("ah_input: authentication hash mismatch " \
"over %d bytes " \
"for packet in SA %s/%08lx:\n" \
"%02x%02x:%02x%02x:%02x%02x:%02x%02x:%02x%02x:%02x%02x, " \
"%02x%02x:%02x%02x:%02x%02x:%02x%02x:%02x%02x:%02x%02x\n",
authsize,
ipsec_address(&saidx->dst),
(u_long) ntohl(sav->spi),
calc[0], calc[1], calc[2], calc[3],
calc[4], calc[5], calc[6], calc[7],
calc[8], calc[9], calc[10], calc[11],
pppp[0], pppp[1], pppp[2], pppp[3],
pppp[4], pppp[5], pppp[6], pppp[7],
pppp[8], pppp[9], pppp[10], pppp[11]
));
AH_STATINC(AH_STAT_BADAUTH);
error = EACCES;
goto bad;
}
/* Fix the Next Protocol field. */
((u_int8_t *) ptr)[protoff] = nxt;
/* Copyback the saved (uncooked) network headers. */
m_copyback(m, 0, skip, ptr);
} else {
/* Fix the Next Protocol field. */
m_copyback(m, protoff, sizeof(u_int8_t), &nxt);
}
free(tc, M_XDATA), tc = NULL; /* No longer needed */
/*
* Header is now authenticated.
*/
m->m_flags |= M_AUTHIPHDR|M_AUTHIPDGM;
/*
* Update replay sequence number, if appropriate.
*/
if (sav->replay) {
u_int32_t seq;
m_copydata(m, skip + offsetof(struct newah, ah_seq),
sizeof (seq), &seq);
if (ipsec_updatereplay(ntohl(seq), sav)) {
AH_STATINC(AH_STAT_REPLAY);
error = ENOBUFS; /*XXX as above*/
goto bad;
}
}
/*
* Remove the AH header and authenticator from the mbuf.
*/
error = m_striphdr(m, skip, rplen + authsize);
if (error) {
DPRINTF(("ah_input_cb: mangled mbuf chain for SA %s/%08lx\n",
ipsec_address(&saidx->dst), (u_long) ntohl(sav->spi)));
AH_STATINC(AH_STAT_HDROPS);
goto bad;
}
IPSEC_COMMON_INPUT_CB(m, sav, skip, protoff, mtag);
KEY_FREESAV(&sav);
splx(s);
return error;
bad:
if (sav)
KEY_FREESAV(&sav);
splx(s);
if (m != NULL)
m_freem(m);
if (tc != NULL)
free(tc, M_XDATA);
if (crp != NULL)
crypto_freereq(crp);
return error;
}
/*
* AH output routine, called by ipsec[46]_process_packet().
*/
static int
ah_output(
struct mbuf *m,
struct ipsecrequest *isr,
struct mbuf **mp,
int skip,
int protoff
)
{
struct secasvar *sav;
struct auth_hash *ahx;
struct cryptodesc *crda;
struct tdb_crypto *tc;
struct mbuf *mi;
struct cryptop *crp;
u_int16_t iplen;
int error, rplen, authsize, maxpacketsize, roff;
u_int8_t prot;
struct newah *ah;
IPSEC_SPLASSERT_SOFTNET("ah_output");
sav = isr->sav;
IPSEC_ASSERT(sav != NULL, ("ah_output: null SA"));
ahx = sav->tdb_authalgxform;
IPSEC_ASSERT(ahx != NULL, ("ah_output: null authentication xform"));
AH_STATINC(AH_STAT_OUTPUT);
/* Figure out header size. */
rplen = HDRSIZE(sav);
/* Check for maximum packet size violations. */
switch (sav->sah->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(("ah_output: unknown/unsupported protocol "
"family %u, SA %s/%08lx\n",
sav->sah->saidx.dst.sa.sa_family,
ipsec_address(&sav->sah->saidx.dst),
(u_long) ntohl(sav->spi)));
AH_STATINC(AH_STAT_NOPF);
error = EPFNOSUPPORT;
goto bad;
}
authsize = AUTHSIZE(sav);
if (rplen + authsize + m->m_pkthdr.len > maxpacketsize) {
DPRINTF(("ah_output: packet in SA %s/%08lx got too big "
"(len %u, max len %u)\n",
ipsec_address(&sav->sah->saidx.dst),
(u_long) ntohl(sav->spi),
rplen + authsize + m->m_pkthdr.len, maxpacketsize));
AH_STATINC(AH_STAT_TOOBIG);
error = EMSGSIZE;
goto bad;
}
/* Update the counters. */
AH_STATADD(AH_STAT_OBYTES, m->m_pkthdr.len - skip);
m = m_clone(m);
if (m == NULL) {
DPRINTF(("ah_output: cannot clone mbuf chain, SA %s/%08lx\n",
ipsec_address(&sav->sah->saidx.dst),
(u_long) ntohl(sav->spi)));
AH_STATINC(AH_STAT_HDROPS);
error = ENOBUFS;
goto bad;
}
/* Inject AH header. */
mi = m_makespace(m, skip, rplen + authsize, &roff);
if (mi == NULL) {
DPRINTF(("ah_output: failed to inject %u byte AH header for SA "
"%s/%08lx\n",
rplen + authsize,
ipsec_address(&sav->sah->saidx.dst),
(u_long) ntohl(sav->spi)));
AH_STATINC(AH_STAT_HDROPS); /*XXX differs from openbsd */
error = ENOBUFS;
goto bad;
}
/*
* The AH header is guaranteed by m_makespace() to be in
* contiguous memory, at roff bytes offset into the returned mbuf.
*/
ah = (struct newah *)(mtod(mi, char *) + roff);
/* Initialize the AH header. */
m_copydata(m, protoff, sizeof(u_int8_t), (char *) &ah->ah_nxt);
ah->ah_len = (rplen + authsize - sizeof(struct ah)) / sizeof(u_int32_t);
ah->ah_reserve = 0;
ah->ah_spi = sav->spi;
/* Zeroize authenticator. */
m_copyback(m, skip + rplen, authsize, ipseczeroes);
/* Insert packet replay counter, as requested. */
if (sav->replay) {
if (sav->replay->count == ~0 &&
(sav->flags & SADB_X_EXT_CYCSEQ) == 0) {
DPRINTF(("ah_output: replay counter wrapped for SA "
"%s/%08lx\n",
ipsec_address(&sav->sah->saidx.dst),
(u_long) ntohl(sav->spi)));
AH_STATINC(AH_STAT_WRAP);
error = EINVAL;
goto bad;
}
#ifdef IPSEC_DEBUG
/* Emulate replay attack when ipsec_replay is TRUE. */
if (!ipsec_replay)
#endif
sav->replay->count++;
ah->ah_seq = htonl(sav->replay->count);
}
/* Get crypto descriptors. */
crp = crypto_getreq(1);
if (crp == NULL) {
DPRINTF(("ah_output: failed to acquire crypto descriptors\n"));
AH_STATINC(AH_STAT_CRYPTO);
error = ENOBUFS;
goto bad;
}
crda = crp->crp_desc;
crda->crd_skip = 0;
crda->crd_inject = skip + rplen;
crda->crd_len = m->m_pkthdr.len;
/* Authentication operation. */
crda->crd_alg = ahx->type;
crda->crd_key = _KEYBUF(sav->key_auth);
crda->crd_klen = _KEYBITS(sav->key_auth);
/* Allocate IPsec-specific opaque crypto info. */
tc = (struct tdb_crypto *) malloc(
sizeof(struct tdb_crypto) + skip, M_XDATA, M_NOWAIT|M_ZERO);
if (tc == NULL) {
crypto_freereq(crp);
DPRINTF(("ah_output: failed to allocate tdb_crypto\n"));
AH_STATINC(AH_STAT_CRYPTO);
error = ENOBUFS;
goto bad;
}
/* Save the skipped portion of the packet. */
m_copydata(m, 0, skip, (tc + 1));
/*
* Fix IP header length on the header used for
* authentication. We don't need to fix the original
* header length as it will be fixed by our caller.
*/
switch (sav->sah->saidx.dst.sa.sa_family) {
#ifdef INET
case AF_INET:
bcopy(((char *)(tc + 1)) +
offsetof(struct ip, ip_len),
&iplen, sizeof(u_int16_t));
iplen = htons(ntohs(iplen) + rplen + authsize);
m_copyback(m, offsetof(struct ip, ip_len),
sizeof(u_int16_t), &iplen);
break;
#endif /* INET */
#ifdef INET6
case AF_INET6:
bcopy(((char *)(tc + 1)) +
offsetof(struct ip6_hdr, ip6_plen),
&iplen, sizeof(u_int16_t));
iplen = htons(ntohs(iplen) + rplen + authsize);
m_copyback(m, offsetof(struct ip6_hdr, ip6_plen),
sizeof(u_int16_t), &iplen);
break;
#endif /* INET6 */
}
/* Fix the Next Header field in saved header. */
((u_int8_t *) (tc + 1))[protoff] = IPPROTO_AH;
/* Update the Next Protocol field in the IP header. */
prot = IPPROTO_AH;
m_copyback(m, protoff, sizeof(u_int8_t), &prot);
/* "Massage" the packet headers for crypto processing. */
error = ah_massage_headers(&m, sav->sah->saidx.dst.sa.sa_family,
skip, ahx->type, 1);
if (error != 0) {
m = NULL; /* mbuf was free'd by ah_massage_headers. */
free(tc, M_XDATA);
crypto_freereq(crp);
goto bad;
}
/* Crypto operation descriptor. */
crp->crp_ilen = m->m_pkthdr.len; /* Total input length. */
crp->crp_flags = CRYPTO_F_IMBUF;
crp->crp_buf = m;
crp->crp_callback = ah_output_cb;
crp->crp_sid = sav->tdb_cryptoid;
crp->crp_opaque = tc;
/* These are passed as-is to the callback. */
tc->tc_isr = isr;
tc->tc_spi = sav->spi;
tc->tc_dst = sav->sah->saidx.dst;
tc->tc_proto = sav->sah->saidx.proto;
tc->tc_skip = skip;
tc->tc_protoff = protoff;
return crypto_dispatch(crp);
bad:
if (m)
m_freem(m);
return (error);
}
/*
* AH output callback from the crypto driver.
*/
static int
ah_output_cb(struct cryptop *crp)
{
int skip, protoff, error;
struct tdb_crypto *tc;
struct ipsecrequest *isr;
struct secasvar *sav;
struct mbuf *m;
void *ptr;
int s, err;
tc = (struct tdb_crypto *) crp->crp_opaque;
IPSEC_ASSERT(tc != NULL, ("ah_output_cb: null opaque data area!"));
skip = tc->tc_skip;
protoff = tc->tc_protoff;
ptr = (tc + 1);
m = (struct mbuf *) crp->crp_buf;
s = splsoftnet();
isr = tc->tc_isr;
sav = KEY_ALLOCSA(&tc->tc_dst, tc->tc_proto, tc->tc_spi, 0, 0);
if (sav == NULL) {
AH_STATINC(AH_STAT_NOTDB);
DPRINTF(("ah_output_cb: SA expired while in crypto\n"));
error = ENOBUFS; /*XXX*/
goto bad;
}
IPSEC_ASSERT(isr->sav == sav, ("ah_output_cb: SA changed\n"));
/* Check for crypto errors. */
if (crp->crp_etype) {
if (sav->tdb_cryptoid != 0)
sav->tdb_cryptoid = crp->crp_sid;
if (crp->crp_etype == EAGAIN) {
KEY_FREESAV(&sav);
splx(s);
return crypto_dispatch(crp);
}
AH_STATINC(AH_STAT_NOXFORM);
DPRINTF(("ah_output_cb: crypto error %d\n", crp->crp_etype));
error = crp->crp_etype;
goto bad;
}
/* Shouldn't happen... */
if (m == NULL) {
AH_STATINC(AH_STAT_CRYPTO);
DPRINTF(("ah_output_cb: bogus returned buffer from crypto\n"));
error = EINVAL;
goto bad;
}
AH_STATINC(AH_STAT_HIST + sav->alg_auth);
/*
* Copy original headers (with the new protocol number) back
* in place.
*/
m_copyback(m, 0, skip, ptr);
/* No longer needed. */
free(tc, M_XDATA);
crypto_freereq(crp);
#ifdef IPSEC_DEBUG
/* Emulate man-in-the-middle attack when ipsec_integrity is TRUE. */
if (ipsec_integrity) {
int alen;
/*
* Corrupt HMAC if we want to test integrity verification of
* the other side.
*/
alen = AUTHSIZE(sav);
m_copyback(m, m->m_pkthdr.len - alen, alen, ipseczeroes);
}
#endif
/* NB: m is reclaimed by ipsec_process_done. */
err = ipsec_process_done(m, isr);
KEY_FREESAV(&sav);
splx(s);
return err;
bad:
if (sav)
KEY_FREESAV(&sav);
splx(s);
if (m)
m_freem(m);
free(tc, M_XDATA);
crypto_freereq(crp);
return error;
}
static struct xformsw ah_xformsw = {
XF_AH, XFT_AUTH, "IPsec AH",
ah_init, ah_zeroize, ah_input, ah_output,
NULL,
};
INITFN void
ah_attach(void)
{
ahstat_percpu = percpu_alloc(sizeof(uint64_t) * AH_NSTATS);
xform_register(&ah_xformsw);
}
#ifdef __FreeBSD__
SYSINIT(ah_xform_init, SI_SUB_PROTO_DOMAIN, SI_ORDER_MIDDLE, ah_attach, NULL);
#endif