/*
* ESP input callback from the crypto driver.
*/
static int
esp_input_cb(struct cryptop *crp)
{
u_int8_t lastthree[3], aalg[AH_HMAC_HASHLEN];
int s, hlen, skip, protoff, error;
struct mbuf *m;
struct cryptodesc *crd;
struct auth_hash *esph;
struct enc_xform *espx;
struct tdb_crypto *tc;
struct m_tag *mtag;
struct secasvar *sav;
struct secasindex *saidx;
caddr_t ptr;
crd = crp->crp_desc;
KASSERT(crd != NULL, ("esp_input_cb: null crypto descriptor!"));
tc = (struct tdb_crypto *) crp->crp_opaque;
KASSERT(tc != NULL, ("esp_input_cb: null opaque crypto data area!"));
skip = tc->tc_skip;
protoff = tc->tc_protoff;
mtag = (struct m_tag *) tc->tc_ptr;
m = (struct mbuf *) crp->crp_buf;
s = splnet();
sav = KEY_ALLOCSA(&tc->tc_dst, tc->tc_proto, tc->tc_spi);
if (sav == NULL) {
espstat.esps_notdb++;
DPRINTF(("esp_input_cb: SA expired while in crypto "
"(SA %s/%08lx proto %u)\n", ipsec_address(&tc->tc_dst),
(u_long) ntohl(tc->tc_spi), tc->tc_proto));
error = ENOBUFS; /*XXX*/
goto bad;
}
saidx = &sav->sah->saidx;
KASSERT(saidx->dst.sa.sa_family == AF_INET ||
saidx->dst.sa.sa_family == AF_INET6,
("ah_input_cb: unexpected protocol family %u",
saidx->dst.sa.sa_family));
esph = sav->tdb_authalgxform;
espx = sav->tdb_encalgxform;
/* Check for crypto errors */
if (crp->crp_etype) {
/* Reset the session ID */
if (sav->tdb_cryptoid != 0)
sav->tdb_cryptoid = crp->crp_sid;
if (crp->crp_etype == EAGAIN) {
KEY_FREESAV(&sav);
splx(s);
return crypto_dispatch(crp);
}
espstat.esps_noxform++;
DPRINTF(("esp_input_cb: crypto error %d\n", crp->crp_etype));
error = crp->crp_etype;
goto bad;
}
/* Shouldn't happen... */
if (m == NULL) {
espstat.esps_crypto++;
DPRINTF(("esp_input_cb: bogus returned buffer from crypto\n"));
error = EINVAL;
goto bad;
}
espstat.esps_hist[sav->alg_enc]++;
/* If authentication was performed, check now. */
if (esph != NULL) {
/*
* If we have a tag, it means an IPsec-aware NIC did
* the verification for us. Otherwise we need to
* check the authentication calculation.
*/
ahstat.ahs_hist[sav->alg_auth]++;
if (mtag == NULL) {
/* Copy the authenticator from the packet */
m_copydata(m, m->m_pkthdr.len - esph->authsize,
esph->authsize, aalg);
ptr = (caddr_t) (tc + 1);
/* Verify authenticator */
if (bcmp(ptr, aalg, esph->authsize) != 0) {
DPRINTF(("esp_input_cb: "
"authentication hash mismatch for packet in SA %s/%08lx\n",
ipsec_address(&saidx->dst),
(u_long) ntohl(sav->spi)));
espstat.esps_badauth++;
error = EACCES;
goto bad;
}
}
/* Remove trailing authenticator */
m_adj(m, -(esph->authsize));
}
/* Release the crypto descriptors */
free(tc, M_XDATA), tc = NULL;
crypto_freereq(crp), crp = NULL;
/*
* Packet is now decrypted.
*/
m->m_flags |= M_DECRYPTED;
/* 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.esps_hdrops++;
DPRINTF(("esp_input_cb: bad mbuf chain, SA %s/%08lx\n",
ipsec_address(&sav->sah->saidx.dst),
(u_long) ntohl(sav->spi)));
goto bad;
}
/* Save the last three bytes of decrypted data */
m_copydata(m, m->m_pkthdr.len - 3, 3, lastthree);
/* Verify pad length */
if (lastthree[1] + 2 > m->m_pkthdr.len - skip) {
espstat.esps_badilen++;
DPRINTF(("esp_input_cb: invalid padding length %d "
"for %u byte packet in SA %s/%08lx\n",
lastthree[1], m->m_pkthdr.len - skip,
ipsec_address(&sav->sah->saidx.dst),
(u_long) ntohl(sav->spi)));
error = EINVAL;
goto bad;
}
/* Verify correct decryption by checking the last padding bytes */
if ((sav->flags & SADB_X_EXT_PMASK) != SADB_X_EXT_PRAND) {
if (lastthree[1] != lastthree[0] && lastthree[1] != 0) {
espstat.esps_badenc++;
DPRINTF(("esp_input_cb: decryption failed "
"for packet in SA %s/%08lx\n",
ipsec_address(&sav->sah->saidx.dst),
(u_long) ntohl(sav->spi)));
DPRINTF(("esp_input_cb: %x %x\n", lastthree[0], lastthree[1]));
error = EINVAL;
goto bad;
}
}
/* Trim the mbuf chain to remove trailing authenticator and padding */
m_adj(m, -(lastthree[1] + 2));
/* Restore the Next Protocol field */
m_copyback(m, protoff, sizeof (u_int8_t), lastthree + 2);
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;
}
+++ sys/netipsec/xform_ipcomp.c 29 Mar 2011 19:24:04 -0000
@@ -326,6 +326,14 @@ ipcomp_input_cb(struct cryptop *crp)
/* Keep the next protocol field */
addr = (uint8_t*) mtod(m, struct ip *) + skip;
nproto = ((struct ipcomp *) addr)->comp_nxt;
+ if (nproto == IPPROTO_IPCOMP || nproto == IPPROTO_AH || nproto == IPPROTO_ESP) {
+ IPCOMP_STATINC(IPCOMP_STAT_HDROPS);
+ DPRINTF(("ipcomp_input_cb: nested ipcomp, IPCA %s/%08lx\n",
+ ipsec_address(&sav->sah->saidx.dst),
+ (u_long) ntohl(sav->spi)));
+ error = EINVAL;
+ goto bad;
+ }
/* Remove the IPCOMP header */
error = m_striphdr(m, skip, hlen);
-------------- next part --------------
Index: sys/netinet6/ipcomp_input.c
===================================================================
RCS file: /cvsroot/src/sys/netinet6/ipcomp_input.c,v
retrieving revision 1.36
diff -u -u -p -r1.36 ipcomp_input.c
--- sys/netinet6/ipcomp_input.c 5 May 2008 13:41:30 -0000 1.36
+++ sys/netinet6/ipcomp_input.c 29 Mar 2011 19:19:00 -0000
@@ -148,6 +148,13 @@ ipcomp4_input(m, va_alist)
ipcomp = mtod(md, struct ipcomp *);
ip = mtod(m, struct ip *);
nxt = ipcomp->comp_nxt;
+ if (nxt == IPPROTO_IPCOMP || nxt == IPPROTO_AH || nxt == IPPROTO_ESP) {
+ /* nested ipcomp - possible attack, not likely useful */
+ ipseclog((LOG_DEBUG, "IPv4 IPComp input: nested ipcomp "
/*
* Potentially decap ESP in UDP frame. Check for an ESP header.
* If present, strip the UDP header and push the result through IPSec.
*
* Returns error if mbuf consumed and/or processed, otherwise 0.
*/
int
udp_ipsec_input(struct mbuf *m, int off, int af)
{
union sockaddr_union dst;
struct secasvar *sav;
struct udphdr *udp;
struct ip *ip;
uint32_t spi;
int hlen;
/*
* Just return if packet doesn't have enough data.
* We need at least [IP header + UDP header + ESP header].
* NAT-Keepalive packet has only one byte of payload, so it
* by default will not be processed.
*/
if (m->m_pkthdr.len < off + sizeof(struct esp))
return (0);
m_copydata(m, off, sizeof(uint32_t), (caddr_t)&spi);
if (spi == 0) /* Non-ESP marker. */
return (0);
/*
* Find SA and check that it is configured for UDP
* encapsulation.
*/
bzero(&dst, sizeof(dst));
dst.sa.sa_family = af;
switch (af) {
#ifdef INET
case AF_INET:
dst.sin.sin_len = sizeof(struct sockaddr_in);
ip = mtod(m, struct ip *);
ip->ip_p = IPPROTO_ESP;
off = offsetof(struct ip, ip_p);
hlen = ip->ip_hl << 2;
dst.sin.sin_addr = ip->ip_dst;
break;
#endif
#ifdef INET6
case AF_INET6:
/* Not yet */
/* FALLTHROUGH */
#endif
default:
ESPSTAT_INC(esps_nopf);
m_freem(m);
return (EPFNOSUPPORT);
}
sav = key_allocsa(&dst, IPPROTO_ESP, spi);
if (sav == NULL) {
ESPSTAT_INC(esps_notdb);
m_freem(m);
return (ENOENT);
}
udp = mtodo(m, hlen);
if (sav->natt == NULL ||
sav->natt->sport != udp->uh_sport ||
sav->natt->dport != udp->uh_dport) {
/* XXXAE: should we check source address? */
ESPSTAT_INC(esps_notdb);
key_freesav(&sav);
m_freem(m);
return (ENOENT);
}
/*
* Remove the UDP header
* Before:
* <--- off --->
* +----+------+-----+
* | IP | UDP | ESP |
* +----+------+-----+
* <-skip->
* After:
* +----+-----+
* | IP | ESP |
* +----+-----+
* <-skip->
*/
m_striphdr(m, hlen, sizeof(*udp));
/*
* We cannot yet update the cksums so clear any h/w cksum flags
* as they are no longer valid.
*/
if (m->m_pkthdr.csum_flags & CSUM_DATA_VALID)
m->m_pkthdr.csum_flags &= ~(CSUM_DATA_VALID | CSUM_PSEUDO_HDR);
/*
* We can update ip_len and ip_sum here, but ipsec4_input_cb()
* will do this anyway, so don't touch them here.
*/
ESPSTAT_INC(esps_input);
(*sav->tdb_xform->xf_input)(m, sav, hlen, off);
return (EINPROGRESS); /* Consumed by IPsec. */
}
