OpenBSD-4.6/sbin/isakmpd/message.c
/* $OpenBSD: message.c,v 1.126 2007/06/02 01:29:11 pvalchev Exp $ */
/* $EOM: message.c,v 1.156 2000/10/10 12:36:39 provos Exp $ */
/*
* Copyright (c) 1998, 1999, 2000, 2001 Niklas Hallqvist. All rights reserved.
* Copyright (c) 1999 Angelos D. Keromytis. All rights reserved.
* Copyright (c) 1999, 2000, 2001, 2004 Håkan Olsson. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
/*
* This code was written under funding by Ericsson Radio Systems.
*/
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <stdlib.h>
#include <string.h>
#include "attribute.h"
#include "cert.h"
#include "constants.h"
#include "crypto.h"
#include "doi.h"
#include "dpd.h"
#include "exchange.h"
#include "field.h"
#include "hash.h"
#include "ipsec.h"
#include "ipsec_num.h"
#include "isakmp.h"
#include "log.h"
#include "message.h"
#include "nat_traversal.h"
#include "prf.h"
#include "sa.h"
#include "timer.h"
#include "transport.h"
#include "util.h"
#include "vendor.h"
#include "virtual.h"
/* A local set datatype, coincidentally fd_set suits our purpose fine. */
typedef fd_set set;
#define ISSET FD_ISSET
#define SET FD_SET
#define ZERO FD_ZERO
static int message_check_duplicate(struct message *);
static int message_encrypt(struct message *);
static int message_index_payload(struct message *, struct payload *,
u_int8_t ,u_int8_t *);
static int message_parse_transform(struct message *, struct payload *,
u_int8_t, u_int8_t *);
static struct field *message_get_field(u_int8_t);
static int message_validate_payload(struct message *, struct payload *,
u_int8_t);
static u_int16_t message_payload_sz(u_int8_t);
static int message_validate_attribute(struct message *, struct payload *);
static int message_validate_cert(struct message *, struct payload *);
static int message_validate_cert_req(struct message *, struct payload *);
static int message_validate_delete(struct message *, struct payload *);
static int message_validate_hash(struct message *, struct payload *);
static int message_validate_id(struct message *, struct payload *);
static int message_validate_key_exch(struct message *, struct payload *);
static int message_validate_nat_d(struct message *, struct payload *);
static int message_validate_nat_oa(struct message *, struct payload *);
static int message_validate_nonce(struct message *, struct payload *);
static int message_validate_notify(struct message *, struct payload *);
static int message_validate_proposal(struct message *, struct payload *);
static int message_validate_sa(struct message *, struct payload *);
static int message_validate_sig(struct message *, struct payload *);
static int message_validate_transform(struct message *, struct payload *);
static int message_validate_vendor(struct message *, struct payload *);
static void message_packet_log(struct message *);
/*
* Fields used for checking monotonic increasing of proposal and transform
* numbers.
*/
static u_int8_t *last_sa = 0;
static u_int32_t last_prop_no;
static u_int8_t *last_prop = 0;
static u_int32_t last_xf_no;
/*
* Allocate a message structure bound to transport T, and with a first
* segment buffer sized SZ, copied from BUF if given.
*/
struct message *
message_alloc(struct transport *t, u_int8_t *buf, size_t sz)
{
struct message *msg;
int i;
/*
* We use calloc(3) because it zeroes the structure which we rely on in
* message_free when determining what sub-allocations to free.
*/
msg = (struct message *)calloc(1, sizeof *msg);
if (!msg)
return 0;
msg->iov = calloc(1, sizeof *msg->iov);
if (!msg->iov) {
message_free(msg);
return 0;
}
msg->iov[0].iov_len = sz;
msg->iov[0].iov_base = malloc(sz);
if (!msg->iov[0].iov_base) {
message_free(msg);
return 0;
}
msg->iovlen = 1;
if (buf)
memcpy(msg->iov[0].iov_base, buf, sz);
msg->nextp = (u_int8_t *)msg->iov[0].iov_base +
ISAKMP_HDR_NEXT_PAYLOAD_OFF;
msg->transport = t;
transport_reference(t);
msg->payload = (struct payload_head *)calloc(ISAKMP_PAYLOAD_MAX,
sizeof *msg->payload);
if (!msg->payload) {
message_free(msg);
return 0;
}
for (i = 0; i < ISAKMP_PAYLOAD_MAX; i++)
TAILQ_INIT(&msg->payload[i]);
TAILQ_INIT(&msg->post_send);
LOG_DBG((LOG_MESSAGE, 90, "message_alloc: allocated %p", msg));
return msg;
}
/*
* Allocate a message suitable for a reply to MSG. Just allocate an empty
* ISAKMP header as the first segment.
*/
struct message *
message_alloc_reply(struct message *msg)
{
struct message *reply;
reply = message_alloc(msg->transport, 0, ISAKMP_HDR_SZ);
reply->exchange = msg->exchange;
reply->isakmp_sa = msg->isakmp_sa;
reply->flags = msg->flags;
if (msg->isakmp_sa)
sa_reference(msg->isakmp_sa);
return reply;
}
/* Free up all resources used by the MSG message. */
void
message_free(struct message *msg)
{
u_int32_t i;
struct payload *payload;
struct post_send *node;
LOG_DBG((LOG_MESSAGE, 20, "message_free: freeing %p", msg));
if (!msg)
return;
if (msg->iov) {
if (msg->orig && msg->orig != (u_int8_t *)msg->iov[0].iov_base)
free(msg->orig);
for (i = 0; i < msg->iovlen; i++)
free(msg->iov[i].iov_base);
free(msg->iov);
}
if (msg->retrans)
timer_remove_event(msg->retrans);
if (msg->payload) {
for (i = 0; i < ISAKMP_PAYLOAD_MAX; i++)
while ((payload = TAILQ_FIRST(&msg->payload[i]))) {
TAILQ_REMOVE(&msg->payload[i], payload, link);
free(payload);
}
free(msg->payload);
}
while ((node = TAILQ_FIRST(&msg->post_send)))
TAILQ_REMOVE(&msg->post_send, node, link);
if (msg->transport) {
/* If we are on the send queue, remove us from there. */
if (msg->flags & MSG_IN_TRANSIT)
TAILQ_REMOVE(msg->transport->vtbl->get_queue(msg),
msg, link);
transport_release(msg->transport);
}
if (msg->isakmp_sa)
sa_release(msg->isakmp_sa);
free(msg);
}
/*
* Generic ISAKMP parser.
* MSG is the ISAKMP message to be parsed. NEXT is the type of the first
* payload to be parsed, and it's pointed to by BUF. ACCEPTED_PAYLOADS
* tells what payloads are accepted and FUNC is a pointer to a function
* to be called for each payload found, which is also responsible for
* freeing the passed ISAKMP message in the failure case.
* Returns the total length of the parsed payloads.
*/
static int
message_parse_payloads(struct message *msg, struct payload *p, u_int8_t next,
u_int8_t *buf, set *accepted_payloads, int (*func)(struct message *,
struct payload *, u_int8_t, u_int8_t *))
{
u_int8_t payload;
u_int16_t len;
int sz = 0;
do {
LOG_DBG((LOG_MESSAGE, 50,
"message_parse_payloads: offset %ld payload %s",
(long)(buf - (u_int8_t *) msg->iov[0].iov_base),
constant_name(isakmp_payload_cst, next)));
/* Does this payload's header fit? */
if (buf + ISAKMP_GEN_SZ > (u_int8_t *)msg->iov[0].iov_base +
msg->iov[0].iov_len) {
log_print("message_parse_payloads: short message");
message_drop(msg,
ISAKMP_NOTIFY_UNEQUAL_PAYLOAD_LENGTHS, 0, 1, 1);
return -1;
}
/* Ponder on the payload that is at BUF... */
payload = next;
/* Look at the next payload's type. */
next = GET_ISAKMP_GEN_NEXT_PAYLOAD(buf);
if (next >= ISAKMP_PAYLOAD_RESERVED_MIN &&
next <= ISAKMP_PAYLOAD_RESERVED_MAX) {
log_print("message_parse_payloads: invalid next "
"payload type %s in payload of type %d",
constant_name(isakmp_payload_cst, next), payload);
message_drop(msg, ISAKMP_NOTIFY_INVALID_PAYLOAD_TYPE,
0, 1, 1);
return -1;
}
/* Reserved fields in ISAKMP messages should be zero. */
if (GET_ISAKMP_GEN_RESERVED(buf) != 0) {
log_print("message_parse_payloads: reserved field "
"non-zero: %x", GET_ISAKMP_GEN_RESERVED(buf));
message_drop(msg, ISAKMP_NOTIFY_PAYLOAD_MALFORMED,
0, 1, 1);
return -1;
}
/*
* Decode and validate the payload length field.
*/
len = GET_ISAKMP_GEN_LENGTH(buf);
if (message_payload_sz(payload) == 0) {
log_print("message_parse_payloads: unknown minimum "
"payload size for payload type %s",
constant_name(isakmp_payload_cst, payload));
message_drop(msg, ISAKMP_NOTIFY_PAYLOAD_MALFORMED,
0, 1, 1);
return -1;
}
if (len < message_payload_sz(payload)) {
log_print("message_parse_payloads: payload too "
"short: %u", len);
message_drop(msg, ISAKMP_NOTIFY_PAYLOAD_MALFORMED,
0, 1, 1);
return -1;
}
if (buf + len > (u_int8_t *)msg->iov[0].iov_base +
msg->iov[0].iov_len) {
log_print("message_parse_payloads: payload too "
"long: %u", len);
message_drop(msg, ISAKMP_NOTIFY_PAYLOAD_MALFORMED,
0, 1, 1);
return -1;
}
/* Ignore most private payloads. */
if (next >= ISAKMP_PAYLOAD_PRIVATE_MIN &&
next != ISAKMP_PAYLOAD_NAT_D_DRAFT &&
next != ISAKMP_PAYLOAD_NAT_OA_DRAFT) {
LOG_DBG((LOG_MESSAGE, 30, "message_parse_payloads: "
"private next payload type %s in payload of "
"type %d ignored",
constant_name(isakmp_payload_cst, next), payload));
goto next_payload;
}
/*
* Check if the current payload is one of the accepted ones at
* this stage.
*/
if (!ISSET(payload, accepted_payloads)) {
log_print("message_parse_payloads: payload type %s "
"unexpected", constant_name(isakmp_payload_cst,
payload));
message_drop(msg, ISAKMP_NOTIFY_INVALID_PAYLOAD_TYPE,
0, 1, 1);
return -1;
}
/* Call the payload handler specified by the caller. */
if (func(msg, p, payload, buf))
return -1;
next_payload:
/* Advance to next payload. */
buf += len;
sz += len;
} while (next != ISAKMP_PAYLOAD_NONE);
return sz;
}
/*
* Parse a proposal payload found in message MSG. PAYLOAD is always
* ISAKMP_PAYLOAD_PROPOSAL and ignored in here. It's needed as the API for
* message_parse_payloads requires it. BUF points to the proposal's
* generic payload header.
*/
static int
message_parse_proposal(struct message *msg, struct payload *p,
u_int8_t payload, u_int8_t *buf)
{
set payload_set;
/* Put the proposal into the proposal bucket. */
if (message_index_payload(msg, p, payload, buf) == -1)
return -1;
ZERO(&payload_set);
SET(ISAKMP_PAYLOAD_TRANSFORM, &payload_set);
if (message_parse_payloads(msg,
TAILQ_LAST(&msg->payload[ISAKMP_PAYLOAD_PROPOSAL], payload_head),
ISAKMP_PAYLOAD_TRANSFORM, buf + ISAKMP_PROP_SPI_OFF +
GET_ISAKMP_PROP_SPI_SZ(buf), &payload_set, message_parse_transform)
== -1)
return -1;
return 0;
}
static int
message_parse_transform(struct message *msg, struct payload *p,
u_int8_t payload, u_int8_t *buf)
{
/* Put the transform into the transform bucket. */
if (message_index_payload(msg, p, payload, buf) == -1)
return -1;
LOG_DBG((LOG_MESSAGE, 50, "Transform %d's attributes",
GET_ISAKMP_TRANSFORM_NO(buf)));
attribute_map(buf + ISAKMP_TRANSFORM_SA_ATTRS_OFF,
GET_ISAKMP_GEN_LENGTH(buf) - ISAKMP_TRANSFORM_SA_ATTRS_OFF,
msg->exchange->doi->debug_attribute, msg);
return 0;
}
static struct field *
message_get_field(u_int8_t payload)
{
switch (payload) {
case ISAKMP_PAYLOAD_SA:
return isakmp_sa_fld;
case ISAKMP_PAYLOAD_PROPOSAL:
return isakmp_prop_fld;
case ISAKMP_PAYLOAD_TRANSFORM:
return isakmp_transform_fld;
case ISAKMP_PAYLOAD_KEY_EXCH:
return isakmp_ke_fld;
case ISAKMP_PAYLOAD_ID:
return isakmp_id_fld;
case ISAKMP_PAYLOAD_CERT:
return isakmp_cert_fld;
case ISAKMP_PAYLOAD_CERT_REQ:
return isakmp_certreq_fld;
case ISAKMP_PAYLOAD_HASH:
return isakmp_hash_fld;
case ISAKMP_PAYLOAD_SIG:
return isakmp_sig_fld;
case ISAKMP_PAYLOAD_NONCE:
return isakmp_nonce_fld;
case ISAKMP_PAYLOAD_NOTIFY:
return isakmp_notify_fld;
case ISAKMP_PAYLOAD_DELETE:
return isakmp_delete_fld;
case ISAKMP_PAYLOAD_VENDOR:
return isakmp_vendor_fld;
case ISAKMP_PAYLOAD_ATTRIBUTE:
return isakmp_attribute_fld;
case ISAKMP_PAYLOAD_NAT_D:
case ISAKMP_PAYLOAD_NAT_D_DRAFT:
return isakmp_nat_d_fld;
case ISAKMP_PAYLOAD_NAT_OA:
case ISAKMP_PAYLOAD_NAT_OA_DRAFT:
return isakmp_nat_oa_fld;
/* Not yet supported and any other unknown payloads. */
case ISAKMP_PAYLOAD_SAK:
case ISAKMP_PAYLOAD_SAT:
case ISAKMP_PAYLOAD_KD:
case ISAKMP_PAYLOAD_SEQ:
case ISAKMP_PAYLOAD_POP:
default:
break;
}
return NULL;
}
static int
message_validate_payload(struct message *m, struct payload *p, u_int8_t payload)
{
switch (payload) {
case ISAKMP_PAYLOAD_SA:
return message_validate_sa(m, p);
case ISAKMP_PAYLOAD_PROPOSAL:
return message_validate_proposal(m, p);
case ISAKMP_PAYLOAD_TRANSFORM:
return message_validate_transform(m, p);
case ISAKMP_PAYLOAD_KEY_EXCH:
return message_validate_key_exch(m, p);
case ISAKMP_PAYLOAD_ID:
return message_validate_id(m, p);
case ISAKMP_PAYLOAD_CERT:
return message_validate_cert(m, p);
case ISAKMP_PAYLOAD_CERT_REQ:
return message_validate_cert_req(m, p);
case ISAKMP_PAYLOAD_HASH:
return message_validate_hash(m, p);
case ISAKMP_PAYLOAD_SIG:
return message_validate_sig(m, p);
case ISAKMP_PAYLOAD_NONCE:
return message_validate_nonce(m, p);
case ISAKMP_PAYLOAD_NOTIFY:
return message_validate_notify(m, p);
case ISAKMP_PAYLOAD_DELETE:
return message_validate_delete(m, p);
case ISAKMP_PAYLOAD_VENDOR:
return message_validate_vendor(m, p);
case ISAKMP_PAYLOAD_ATTRIBUTE:
return message_validate_attribute(m, p);
case ISAKMP_PAYLOAD_NAT_D:
case ISAKMP_PAYLOAD_NAT_D_DRAFT:
return message_validate_nat_d(m, p);
case ISAKMP_PAYLOAD_NAT_OA:
case ISAKMP_PAYLOAD_NAT_OA_DRAFT:
return message_validate_nat_oa(m, p);
/* Not yet supported and any other unknown payloads. */
case ISAKMP_PAYLOAD_SAK:
case ISAKMP_PAYLOAD_SAT:
case ISAKMP_PAYLOAD_KD:
case ISAKMP_PAYLOAD_SEQ:
case ISAKMP_PAYLOAD_POP:
default:
break;
}
message_drop(m, ISAKMP_NOTIFY_INVALID_PAYLOAD_TYPE, 0, 1, 1);
return -1;
}
/* Check payloads for their required minimum size. */
static u_int16_t
message_payload_sz(u_int8_t payload)
{
switch (payload) {
case ISAKMP_PAYLOAD_SA:
return ISAKMP_SA_SZ;
case ISAKMP_PAYLOAD_PROPOSAL:
return ISAKMP_PROP_SZ;
case ISAKMP_PAYLOAD_TRANSFORM:
return ISAKMP_TRANSFORM_SZ;
case ISAKMP_PAYLOAD_KEY_EXCH:
return ISAKMP_KE_SZ;
case ISAKMP_PAYLOAD_ID:
return ISAKMP_ID_SZ;
case ISAKMP_PAYLOAD_CERT:
return ISAKMP_CERT_SZ;
case ISAKMP_PAYLOAD_CERT_REQ:
return ISAKMP_CERTREQ_SZ;
case ISAKMP_PAYLOAD_HASH:
return ISAKMP_HASH_SZ;
case ISAKMP_PAYLOAD_SIG:
return ISAKMP_SIG_SZ;
case ISAKMP_PAYLOAD_NONCE:
return ISAKMP_NONCE_SZ;
case ISAKMP_PAYLOAD_NOTIFY:
return ISAKMP_NOTIFY_SZ;
case ISAKMP_PAYLOAD_DELETE:
return ISAKMP_DELETE_SZ;
case ISAKMP_PAYLOAD_VENDOR:
return ISAKMP_VENDOR_SZ;
case ISAKMP_PAYLOAD_ATTRIBUTE:
return ISAKMP_ATTRIBUTE_SZ;
case ISAKMP_PAYLOAD_NAT_D:
case ISAKMP_PAYLOAD_NAT_D_DRAFT:
return ISAKMP_NAT_D_SZ;
case ISAKMP_PAYLOAD_NAT_OA:
case ISAKMP_PAYLOAD_NAT_OA_DRAFT:
return ISAKMP_NAT_OA_SZ;
/* Not yet supported and any other unknown payloads. */
case ISAKMP_PAYLOAD_SAK:
case ISAKMP_PAYLOAD_SAT:
case ISAKMP_PAYLOAD_KD:
case ISAKMP_PAYLOAD_SEQ:
case ISAKMP_PAYLOAD_POP:
default:
return 0;
}
}
/* Validate the attribute payload P in message MSG. */
static int
message_validate_attribute(struct message *msg, struct payload *p)
{
/* If we don't have an exchange yet, create one. */
if (!msg->exchange) {
if (zero_test((u_int8_t *) msg->iov[0].iov_base +
ISAKMP_HDR_MESSAGE_ID_OFF, ISAKMP_HDR_MESSAGE_ID_LEN))
msg->exchange = exchange_setup_p1(msg,
IPSEC_DOI_IPSEC);
else
msg->exchange = exchange_setup_p2(msg,
IPSEC_DOI_IPSEC);
if (!msg->exchange) {
log_print("message_validate_attribute: can not "
"create exchange");
message_free(msg);
return -1;
}
}
return 0;
}
/* Validate the certificate payload P in message MSG. */
static int
message_validate_cert(struct message *msg, struct payload *p)
{
if (GET_ISAKMP_CERT_ENCODING(p->p) >= ISAKMP_CERTENC_RESERVED_MIN) {
message_drop(msg, ISAKMP_NOTIFY_INVALID_CERT_ENCODING, 0, 1,
1);
return -1;
}
return 0;
}
/* Validate the certificate request payload P in message MSG. */
static int
message_validate_cert_req(struct message *msg, struct payload *p)
{
struct cert_handler *cert;
size_t len =
GET_ISAKMP_GEN_LENGTH(p->p) - ISAKMP_CERTREQ_AUTHORITY_OFF;
if (GET_ISAKMP_CERTREQ_TYPE(p->p) >= ISAKMP_CERTENC_RESERVED_MIN) {
message_drop(msg, ISAKMP_NOTIFY_INVALID_CERT_ENCODING, 0, 1,
1);
return -1;
}
/*
* Check the certificate types we support and if an acceptable
* authority is included in the payload check if it can be decoded
*/
cert = cert_get(GET_ISAKMP_CERTREQ_TYPE(p->p));
if (!cert || (len && !cert->certreq_validate(p->p +
ISAKMP_CERTREQ_AUTHORITY_OFF, len))) {
message_drop(msg, ISAKMP_NOTIFY_CERT_TYPE_UNSUPPORTED, 0, 1,
1);
return -1;
}
return 0;
}
/*
* Validate the delete payload P in message MSG. As a side-effect, create
* an exchange if we do not have one already.
*/
static int
message_validate_delete(struct message *msg, struct payload *p)
{
u_int8_t proto = GET_ISAKMP_DELETE_PROTO(p->p);
struct doi *doi;
struct sa *sa, *isakmp_sa;
struct sockaddr *dst, *dst_isa;
u_int32_t nspis = GET_ISAKMP_DELETE_NSPIS(p->p);
u_int8_t *spis = (u_int8_t *)p->p + ISAKMP_DELETE_SPI_OFF;
u_int32_t i;
char *addr;
/* Only accept authenticated DELETEs. */
if ((msg->flags & MSG_AUTHENTICATED) == 0) {
log_print("message_validate_delete: "
"got unauthenticated DELETE");
message_free(msg);
return -1;
}
doi = doi_lookup(GET_ISAKMP_DELETE_DOI(p->p));
if (!doi) {
log_print("message_validate_delete: DOI not supported");
message_free(msg);
return -1;
}
/* If we don't have an exchange yet, create one. */
if (!msg->exchange) {
if (zero_test((u_int8_t *) msg->iov[0].iov_base
+ ISAKMP_HDR_MESSAGE_ID_OFF, ISAKMP_HDR_MESSAGE_ID_LEN))
msg->exchange = exchange_setup_p1(msg, doi->id);
else
msg->exchange = exchange_setup_p2(msg, doi->id);
if (!msg->exchange) {
log_print("message_validate_delete: can not create "
"exchange");
message_free(msg);
return -1;
}
}
/* Only accept DELETE as part of an INFORMATIONAL exchange. */
if (msg->exchange->type != ISAKMP_EXCH_INFO) {
log_print("message_validate_delete: delete in exchange other "
"than INFO: %s", constant_name(isakmp_exch_cst,
msg->exchange->type));
message_free(msg);
return -1;
}
if (proto != ISAKMP_PROTO_ISAKMP && doi->validate_proto(proto)) {
log_print("message_validate_delete: protocol not supported");
message_free(msg);
return -1;
}
/* Validate the SPIs. */
for (i = 0; i < nspis; i++) {
/* Get ISAKMP SA protecting this message. */
isakmp_sa = msg->isakmp_sa;
if (!isakmp_sa) {
/* XXX should not happen? */
log_print("message_validate_delete: invalid spi (no "
"valid ISAKMP SA found)");
message_free(msg);
return -1;
}
isakmp_sa->transport->vtbl->get_dst(isakmp_sa->transport,
&dst_isa);
/* Get SA to be deleted. */
msg->transport->vtbl->get_dst(msg->transport, &dst);
if (proto == ISAKMP_PROTO_ISAKMP)
sa = sa_lookup_isakmp_sa(dst, spis + i
* ISAKMP_HDR_COOKIES_LEN);
else
sa = ipsec_sa_lookup(dst, ((u_int32_t *) spis)[i],
proto);
if (!sa) {
LOG_DBG((LOG_MESSAGE, 50, "message_validate_delete: "
"invalid spi (no valid SA found)"));
message_free(msg);
return -1;
}
sa->transport->vtbl->get_dst(sa->transport, &dst);
/* Destination addresses must match. */
if (dst->sa_family != dst_isa->sa_family ||
memcmp(sockaddr_addrdata(dst_isa), sockaddr_addrdata(dst),
sockaddr_addrlen(dst))) {
sockaddr2text(dst_isa, &addr, 0);
log_print("message_validate_delete: invalid spi "
"(illegal delete request from %s)", addr);
free(addr);
message_free(msg);
return -1;
}
}
return 0;
}
/*
* Validate the hash payload P in message MSG.
*/
static int
message_validate_hash(struct message *msg, struct payload *p)
{
struct sa *isakmp_sa = msg->isakmp_sa;
struct ipsec_sa *isa;
struct hash *hash;
struct payload *hashp = payload_first(msg, ISAKMP_PAYLOAD_HASH);
struct prf *prf;
u_int8_t *rest;
u_int8_t message_id[ISAKMP_HDR_MESSAGE_ID_LEN];
size_t rest_len;
/* active exchanges other than INFORMATIONAL validates hash payload. */
if (msg->exchange && (msg->exchange->type != ISAKMP_EXCH_INFO))
return 0;
if (isakmp_sa == NULL)
goto invalid;
isa = isakmp_sa->data;
hash = hash_get(isa->hash);
if (hash == NULL)
goto invalid;
/* If no SKEYID_a, we can not do anything (should not happen). */
if (!isa->skeyid_a)
goto invalid;
/* Allocate the prf and start calculating our HASH(1). */
LOG_DBG_BUF((LOG_MISC, 90, "message_validate_hash: SKEYID_a",
isa->skeyid_a, isa->skeyid_len));
prf = prf_alloc(isa->prf_type, hash->type, isa->skeyid_a,
isa->skeyid_len);
if (!prf) {
message_free(msg);
return -1;
}
/* This is not an active exchange. */
GET_ISAKMP_HDR_MESSAGE_ID(msg->iov[0].iov_base, message_id);
prf->Init(prf->prfctx);
LOG_DBG_BUF((LOG_MISC, 90, "message_validate_hash: message_id",
message_id, ISAKMP_HDR_MESSAGE_ID_LEN));
prf->Update(prf->prfctx, message_id, ISAKMP_HDR_MESSAGE_ID_LEN);
rest = hashp->p + GET_ISAKMP_GEN_LENGTH(hashp->p);
rest_len = (GET_ISAKMP_HDR_LENGTH(msg->iov[0].iov_base) - (rest -
(u_int8_t *)msg->iov[0].iov_base));
LOG_DBG_BUF((LOG_MISC, 90,
"message_validate_hash: payloads after HASH(1)", rest, rest_len));
prf->Update(prf->prfctx, rest, rest_len);
prf->Final(hash->digest, prf->prfctx);
prf_free(prf);
if (memcmp(hashp->p + ISAKMP_HASH_DATA_OFF, hash->digest,
hash->hashsize))
goto invalid;
/* Mark the HASH as handled. */
hashp->flags |= PL_MARK;
/* Mark message as authenticated. */
msg->flags |= MSG_AUTHENTICATED;
return 0;
invalid:
log_print("message_validate_hash: invalid hash information");
message_drop(msg, ISAKMP_NOTIFY_INVALID_HASH_INFORMATION, 0, 1, 1);
return -1;
}
/* Validate the identification payload P in message MSG. */
static int
message_validate_id(struct message *msg, struct payload *p)
{
struct exchange *exchange = msg->exchange;
size_t len = GET_ISAKMP_GEN_LENGTH(p->p);
if (!exchange) {
/* We should have an exchange at this point. */
log_print("message_validate_id: payload out of sequence");
message_drop(msg, ISAKMP_NOTIFY_PAYLOAD_MALFORMED, 0, 1, 1);
return -1;
}
if (exchange->doi &&
exchange->doi->validate_id_information(GET_ISAKMP_ID_TYPE(p->p),
p->p + ISAKMP_ID_DOI_DATA_OFF, p->p + ISAKMP_ID_DATA_OFF,
len - ISAKMP_ID_DATA_OFF, exchange)) {
message_drop(msg, ISAKMP_NOTIFY_INVALID_ID_INFORMATION, 0, 1,
1);
return -1;
}
return 0;
}
/* Validate the key exchange payload P in message MSG. */
static int
message_validate_key_exch(struct message *msg, struct payload *p)
{
struct exchange *exchange = msg->exchange;
size_t len = GET_ISAKMP_GEN_LENGTH(p->p);
if (!exchange) {
/* We should have an exchange at this point. */
log_print("message_validate_key_exch: "
"payload out of sequence");
message_drop(msg, ISAKMP_NOTIFY_PAYLOAD_MALFORMED, 0, 1, 1);
return -1;
}
if (exchange->doi && exchange->doi->validate_key_information(p->p +
ISAKMP_KE_DATA_OFF, len - ISAKMP_KE_DATA_OFF)) {
message_drop(msg, ISAKMP_NOTIFY_INVALID_KEY_INFORMATION,
0, 1, 1);
return -1;
}
return 0;
}
/* Validate the NAT-D payload P in message MSG. */
static int
message_validate_nat_d(struct message *msg, struct payload *p)
{
struct exchange *exchange = msg->exchange;
if (!exchange) {
/* We should have an exchange at this point. */
log_print("message_validate_nat_d: payload out of sequence");
message_drop(msg, ISAKMP_NOTIFY_PAYLOAD_MALFORMED, 0, 1, 1);
return -1;
}
if (exchange->phase != 1) {
log_print("message_validate_nat_d: "
"NAT-D payload must be in phase 1");
message_drop(msg, ISAKMP_NOTIFY_PAYLOAD_MALFORMED, 0, 1, 1);
return -1;
}
/* Mark as handled. */
p->flags |= PL_MARK;
return 0;
}
/* Validate the NAT-OA payload P in message MSG. */
static int
message_validate_nat_oa(struct message *msg, struct payload *p)
{
struct exchange *exchange = msg->exchange;
if (!exchange) {
/* We should have an exchange at this point. */
log_print("message_validate_nat_d: payload out of sequence");
message_drop(msg, ISAKMP_NOTIFY_PAYLOAD_MALFORMED, 0, 1, 1);
return -1;
}
#ifdef notyet /* XXX Probably never, due to patent issues. */
/* Mark as handled. */
p->flags |= PL_MARK;
#endif
return 0;
}
/* Validate the nonce payload P in message MSG. */
static int
message_validate_nonce(struct message *msg, struct payload *p)
{
if (!msg->exchange) {
/* We should have an exchange at this point. */
log_print("message_validate_nonce: payload out of sequence");
message_drop(msg, ISAKMP_NOTIFY_PAYLOAD_MALFORMED, 0, 1, 1);
return -1;
}
/* Nonces require no specific validation. */
return 0;
}
/*
* Validate the notify payload P in message MSG. As a side-effect, create
* an exchange if we do not have one already.
*/
static int
message_validate_notify(struct message *msg, struct payload *p)
{
u_int8_t proto = GET_ISAKMP_NOTIFY_PROTO(p->p);
u_int16_t type = GET_ISAKMP_NOTIFY_MSG_TYPE(p->p);
struct doi *doi;
doi = doi_lookup(GET_ISAKMP_NOTIFY_DOI(p->p));
if (!doi) {
log_print("message_validate_notify: DOI not supported");
message_free(msg);
return -1;
}
/* If we don't have an exchange yet, create one. */
if (!msg->exchange) {
if (zero_test((u_int8_t *) msg->iov[0].iov_base +
ISAKMP_HDR_MESSAGE_ID_OFF, ISAKMP_HDR_MESSAGE_ID_LEN))
msg->exchange = exchange_setup_p1(msg, doi->id);
else
msg->exchange = exchange_setup_p2(msg, doi->id);
if (!msg->exchange) {
log_print("message_validate_notify: can not create "
"exchange");
message_free(msg);
return -1;
}
}
if (proto != ISAKMP_PROTO_ISAKMP && doi->validate_proto(proto)) {
log_print("message_validate_notify: protocol not supported");
message_free(msg);
return -1;
}
/* Validate the SPI. XXX Just ISAKMP for now. */
if (proto == ISAKMP_PROTO_ISAKMP &&
GET_ISAKMP_NOTIFY_SPI_SZ(p->p) == ISAKMP_HDR_COOKIES_LEN &&
msg->isakmp_sa &&
memcmp(p->p + ISAKMP_NOTIFY_SPI_OFF, msg->isakmp_sa->cookies,
ISAKMP_HDR_COOKIES_LEN) != 0) {
log_print("message_validate_notify: bad cookies");
message_drop(msg, ISAKMP_NOTIFY_INVALID_SPI, 0, 1, 1);
return -1;
}
if (type < ISAKMP_NOTIFY_INVALID_PAYLOAD_TYPE ||
(type >= ISAKMP_NOTIFY_RESERVED_MIN &&
type < ISAKMP_NOTIFY_PRIVATE_MIN) ||
(type >= ISAKMP_NOTIFY_STATUS_RESERVED1_MIN &&
type <= ISAKMP_NOTIFY_STATUS_RESERVED1_MAX) ||
(type >= ISAKMP_NOTIFY_STATUS_DOI_MIN &&
type <= ISAKMP_NOTIFY_STATUS_DOI_MAX &&
doi->validate_notification(type)) ||
type >= ISAKMP_NOTIFY_STATUS_RESERVED2_MIN) {
log_print("message_validate_notify: "
"message type not supported");
message_free(msg);
return -1;
}
return 0;
}
/* Validate the proposal payload P in message MSG. */
static int
message_validate_proposal(struct message *msg, struct payload *p)
{
u_int8_t proto = GET_ISAKMP_PROP_PROTO(p->p);
u_int8_t *sa = p->context->p;
if (!msg->exchange) {
/* We should have an exchange at this point. */
log_print("message_validate_proposal: "
"payload out of sequence");
message_drop(msg, ISAKMP_NOTIFY_PAYLOAD_MALFORMED, 0, 1, 1);
return -1;
}
if (proto != ISAKMP_PROTO_ISAKMP &&
msg->exchange->doi->validate_proto(proto)) {
message_drop(msg, ISAKMP_NOTIFY_INVALID_PROTOCOL_ID, 0, 1, 1);
return -1;
}
/* Check that we get monotonically increasing proposal IDs per SA. */
if (sa != last_sa)
last_sa = sa;
else if (GET_ISAKMP_PROP_NO(p->p) < last_prop_no) {
message_drop(msg, ISAKMP_NOTIFY_BAD_PROPOSAL_SYNTAX, 0, 1, 1);
return -1;
}
last_prop_no = GET_ISAKMP_PROP_NO(p->p);
/* XXX Validate the SPI, and other syntactic things. */
return 0;
}
/*
* Validate the SA payload P in message MSG.
* Aside from normal validation, note what DOI is in use for other
* validation routines to look at. Also index the proposal payloads
* on the fly.
* XXX This assumes PAYLOAD_SA is always the first payload
* to be validated, which is true for IKE, except for quick mode where
* a PAYLOAD_HASH comes first, but in that specific case it does not matter.
* XXX Make sure the above comment is relevant, isn't SA always checked
* first due to the IANA assigned payload number?
*/
static int
message_validate_sa(struct message *msg, struct payload *p)
{
set payload_set;
size_t len;
u_int32_t doi_id;
struct exchange *exchange = msg->exchange;
u_int8_t *pkt = msg->iov[0].iov_base;
doi_id = GET_ISAKMP_SA_DOI(p->p);
if (!doi_lookup(doi_id)) {
log_print("message_validate_sa: DOI not supported");
message_drop(msg, ISAKMP_NOTIFY_DOI_NOT_SUPPORTED, 0, 1, 1);
return -1;
}
/*
* It's time to figure out what SA this message is about. If it is
* already set, then we are creating a new phase 1 SA. Otherwise,
* lookup the SA using the cookies and the message ID. If we cannot
* find it, and the phase 1 SA is ready, setup a phase 2 SA.
*/
if (!exchange) {
if (zero_test(pkt + ISAKMP_HDR_RCOOKIE_OFF,
ISAKMP_HDR_RCOOKIE_LEN))
exchange = exchange_setup_p1(msg, doi_id);
else if (msg->isakmp_sa->flags & SA_FLAG_READY)
exchange = exchange_setup_p2(msg, doi_id);
else {
/* XXX What to do here? */
message_free(msg);
return -1;
}
if (!exchange) {
/* XXX Log? */
message_free(msg);
return -1;
}
}
msg->exchange = exchange;
/*
* Create a struct sa for each SA payload handed to us unless we are
* the initiator where we only will count them.
*/
if (exchange->initiator) {
/* XXX Count SA payloads. */
} else if (sa_create(exchange, msg->transport)) {
/* XXX Remove exchange if we just created it? */
message_free(msg);
return -1;
}
if (exchange->phase == 1) {
msg->isakmp_sa = TAILQ_FIRST(&exchange->sa_list);
if (msg->isakmp_sa)
sa_reference(msg->isakmp_sa);
}
/*
* Let the DOI validate the situation, at the same time it tells us
* what the length of the situation field is.
*/
if (exchange->doi->validate_situation(p->p + ISAKMP_SA_SIT_OFF, &len,
GET_ISAKMP_GEN_LENGTH(p->p) - ISAKMP_SA_SIT_OFF)) {
log_print("message_validate_sa: situation not supported");
message_drop(msg, ISAKMP_NOTIFY_SITUATION_NOT_SUPPORTED,
0, 1, 1);
return -1;
}
/*
* Reset the fields we base our proposal & transform number checks
* on.
*/
last_sa = last_prop = 0;
last_prop_no = last_xf_no = 0;
/* Go through the PROPOSAL payloads. */
ZERO(&payload_set);
SET(ISAKMP_PAYLOAD_PROPOSAL, &payload_set);
if (message_parse_payloads(msg, p, ISAKMP_PAYLOAD_PROPOSAL,
p->p + ISAKMP_SA_SIT_OFF + len, &payload_set,
message_parse_proposal) == -1)
return -1;
return 0;
}
/* Validate the signature payload P in message MSG. */
static int
message_validate_sig(struct message *msg, struct payload *p)
{
if (!msg->exchange) {
/* We should have an exchange at this point. */
log_print("message_validate_sig: payload out of sequence");
message_drop(msg, ISAKMP_NOTIFY_PAYLOAD_MALFORMED, 0, 1, 1);
return -1;
}
/* XXX Not implemented yet. */
return 0;
}
/* Validate the transform payload P in message MSG. */
static int
message_validate_transform(struct message *msg, struct payload *p)
{
u_int8_t proto = GET_ISAKMP_PROP_PROTO(p->context->p);
u_int8_t *prop = p->context->p;
if (!msg->exchange) {
/* We should have an exchange at this point. */
log_print("message_validate_transform: "
"payload out of sequence");
message_drop(msg, ISAKMP_NOTIFY_PAYLOAD_MALFORMED, 0, 1, 1);
return -1;
}
if (msg->exchange->doi
->validate_transform_id(proto, GET_ISAKMP_TRANSFORM_ID(p->p))) {
message_drop(msg, ISAKMP_NOTIFY_INVALID_TRANSFORM_ID, 0, 1, 1);
return -1;
}
/* Check that the reserved field is zero. */
if (!zero_test(p->p + ISAKMP_TRANSFORM_RESERVED_OFF,
ISAKMP_TRANSFORM_RESERVED_LEN)) {
message_drop(msg, ISAKMP_NOTIFY_PAYLOAD_MALFORMED, 0, 1, 1);
return -1;
}
/*
* Check that we get monotonically increasing transform numbers per
* proposal.
*/
if (prop != last_prop)
last_prop = prop;
else if (GET_ISAKMP_TRANSFORM_NO(p->p) <= last_xf_no) {
message_drop(msg, ISAKMP_NOTIFY_BAD_PROPOSAL_SYNTAX, 0, 1, 1);
return -1;
}
last_xf_no = GET_ISAKMP_TRANSFORM_NO(p->p);
/* Validate the attributes. */
if (attribute_map(p->p + ISAKMP_TRANSFORM_SA_ATTRS_OFF,
GET_ISAKMP_GEN_LENGTH(p->p) - ISAKMP_TRANSFORM_SA_ATTRS_OFF,
msg->exchange->doi->validate_attribute, msg)) {
message_drop(msg, ISAKMP_NOTIFY_ATTRIBUTES_NOT_SUPPORTED,
0, 1, 1);
return -1;
}
return 0;
}
/* Validate the vendor payload P in message MSG. */
static int
message_validate_vendor(struct message *msg, struct payload *p)
{
if (!msg->exchange) {
/* We should have an exchange at this point. */
log_print("message_validate_vendor: payload out of sequence");
message_drop(msg, ISAKMP_NOTIFY_PAYLOAD_MALFORMED, 0, 1, 1);
return -1;
}
/* Vendor IDs are only allowed in phase 1. */
if (msg->exchange->phase != 1) {
message_drop(msg, ISAKMP_NOTIFY_INVALID_PAYLOAD_TYPE, 0, 1, 1);
return -1;
}
check_vendor_openbsd(msg, p);
dpd_check_vendor_payload(msg, p);
nat_t_check_vendor_payload(msg, p);
if (!(p->flags & PL_MARK))
LOG_DBG((LOG_MESSAGE, 40, "message_validate_vendor: "
"vendor ID seen"));
return 0;
}
/*
* Add an index-record pointing to the payload at BUF in message MSG
* to the PAYLOAD bucket of payloads. This allows us to quickly reference
* payloads by type. Also stash the parent payload P link into the new
* node so we can go from transforms -> payloads -> SAs.
*/
static int
message_index_payload(struct message *msg, struct payload *p, u_int8_t payload,
u_int8_t *buf)
{
struct payload *payload_node;
/* Put the payload pointer into the right bucket. */
payload_node = malloc(sizeof *payload_node);
if (!payload_node) {
message_free(msg);
return -1;
}
payload_node->p = buf;
payload_node->context = p;
payload_node->flags = 0;
TAILQ_INSERT_TAIL(&msg->payload[payload], payload_node, link);
return 0;
}
/*
* Group each payload found in MSG by type for easy reference later.
* While doing this, validate the generic parts of the message structure too.
* NEXT is the 1st payload's type. This routine will also register the
* computed message length (i.e. without padding) in msg->iov[0].iov_len.
*/
static int
message_sort_payloads(struct message *msg, u_int8_t next)
{
set payload_set;
int i, sz;
ZERO(&payload_set);
for (i = ISAKMP_PAYLOAD_SA; i < ISAKMP_PAYLOAD_MAX; i++)
if (i != ISAKMP_PAYLOAD_PROPOSAL && i !=
ISAKMP_PAYLOAD_TRANSFORM)
SET(i, &payload_set);
sz = message_parse_payloads(msg, 0, next,
(u_int8_t *)msg->iov[0].iov_base + ISAKMP_HDR_SZ, &payload_set,
message_index_payload);
if (sz == -1)
return -1;
msg->iov[0].iov_len = ISAKMP_HDR_SZ + sz;
SET_ISAKMP_HDR_LENGTH(msg->iov[0].iov_base, ISAKMP_HDR_SZ + sz);
return 0;
}
/* Run all the generic payload tests that the drafts specify. */
static int
message_validate_payloads(struct message *msg)
{
int i;
struct payload *p;
struct field *f;
for (i = ISAKMP_PAYLOAD_SA; i < ISAKMP_PAYLOAD_MAX; i++)
TAILQ_FOREACH(p, &msg->payload[i], link) {
LOG_DBG((LOG_MESSAGE, 60, "message_validate_payloads: "
"payload %s at %p of message %p",
constant_name(isakmp_payload_cst, i), p->p, msg));
if ((f = message_get_field(i)) != NULL)
field_dump_payload(f, p->p);
if (message_validate_payload(msg, p, i))
return -1;
}
return 0;
}
/*
* All incoming messages go through here. We do generic validity checks
* and try to find or establish SAs. Last but not least we try to find
* the exchange this message, MSG, is part of, and feed it there.
*/
int
message_recv(struct message *msg)
{
u_int8_t *buf = msg->iov[0].iov_base;
size_t sz = msg->iov[0].iov_len;
u_int8_t exch_type;
int setup_isakmp_sa, msgid_is_zero;
u_int8_t flags;
struct keystate *ks = 0;
struct proto tmp_proto;
struct sa tmp_sa;
struct transport *t;
/* Messages shorter than an ISAKMP header are bad. */
if (sz < ISAKMP_HDR_SZ || sz != GET_ISAKMP_HDR_LENGTH(buf)) {
log_print("message_recv: bad message length");
message_drop(msg, 0, 0, 1, 1);
return -1;
}
/* Possibly dump a raw hex image of the message to the log channel. */
message_dump_raw("message_recv", msg, LOG_MESSAGE);
/*
* If the responder cookie is zero, this is a request to setup an
* ISAKMP SA. Otherwise the cookies should refer to an existing
* ISAKMP SA.
*
* XXX This is getting ugly, please reread later to see if it can be
* made nicer.
*/
setup_isakmp_sa = zero_test(buf + ISAKMP_HDR_RCOOKIE_OFF,
ISAKMP_HDR_RCOOKIE_LEN);
if (setup_isakmp_sa) {
/*
* This might be a retransmission of a former ISAKMP SA setup
* message. If so, just drop it.
* XXX Must we really look in both the SA and exchange pools?
*/
if (exchange_lookup_from_icookie(buf + ISAKMP_HDR_ICOOKIE_OFF) ||
sa_lookup_from_icookie(buf + ISAKMP_HDR_ICOOKIE_OFF)) {
/*
* XXX Later we should differentiate between
* retransmissions and potential replay attacks.
*/
LOG_DBG((LOG_MESSAGE, 90,
"message_recv: dropping setup for existing SA"));
message_free(msg);
return -1;
}
} else {
msg->isakmp_sa = sa_lookup_by_header(buf, 0);
if (msg->isakmp_sa)
sa_reference(msg->isakmp_sa);
/*
* If we cannot find an ISAKMP SA out of the cookies, this is
* either a responder's first reply, and we need to upgrade
* our exchange, or it's just plain invalid cookies.
*/
if (!msg->isakmp_sa) {
msg->exchange = exchange_lookup_from_icookie(buf +
ISAKMP_HDR_ICOOKIE_OFF);
if (msg->exchange && msg->exchange->phase == 1 &&
zero_test(msg->exchange->cookies +
ISAKMP_HDR_RCOOKIE_OFF, ISAKMP_HDR_RCOOKIE_LEN))
exchange_upgrade_p1(msg);
else {
log_print("message_recv: invalid cookie(s) "
"%08x%08x %08x%08x",
decode_32(buf + ISAKMP_HDR_ICOOKIE_OFF),
decode_32(buf + ISAKMP_HDR_ICOOKIE_OFF + 4),
decode_32(buf + ISAKMP_HDR_RCOOKIE_OFF),
decode_32(buf + ISAKMP_HDR_RCOOKIE_OFF + 4));
tmp_proto.sa = &tmp_sa;
tmp_sa.doi = doi_lookup(ISAKMP_DOI_ISAKMP);
tmp_proto.proto = ISAKMP_PROTO_ISAKMP;
tmp_proto.spi_sz[1] = ISAKMP_HDR_COOKIES_LEN;
tmp_proto.spi[1] =
buf + ISAKMP_HDR_COOKIES_OFF;
message_drop(msg, ISAKMP_NOTIFY_INVALID_COOKIE,
&tmp_proto, 1, 1);
return -1;
}
#if 0
msg->isakmp_sa = sa_lookup_from_icookie(buf +
ISAKMP_HDR_ICOOKIE_OFF);
if (msg->isakmp_sa)
sa_isakmp_upgrade(msg);
#endif
}
msg->exchange = exchange_lookup(buf, 1);
}
if (message_check_duplicate(msg))
return -1;
if (GET_ISAKMP_HDR_NEXT_PAYLOAD(buf) >= ISAKMP_PAYLOAD_RESERVED_MIN) {
log_print("message_recv: invalid payload type %d in ISAKMP "
"header (check passphrases, if applicable and in Phase 1)",
GET_ISAKMP_HDR_NEXT_PAYLOAD(buf));
message_drop(msg, ISAKMP_NOTIFY_INVALID_PAYLOAD_TYPE, 0, 1, 1);
return -1;
}
/* Validate that the message is of version 1.0. */
if (ISAKMP_VERSION_MAJOR(GET_ISAKMP_HDR_VERSION(buf)) != 1) {
log_print("message_recv: invalid version major %d",
ISAKMP_VERSION_MAJOR(GET_ISAKMP_HDR_VERSION(buf)));
message_drop(msg, ISAKMP_NOTIFY_INVALID_MAJOR_VERSION, 0, 1,
1);
return -1;
}
if (ISAKMP_VERSION_MINOR(GET_ISAKMP_HDR_VERSION(buf)) != 0) {
log_print("message_recv: invalid version minor %d",
ISAKMP_VERSION_MINOR(GET_ISAKMP_HDR_VERSION(buf)));
message_drop(msg, ISAKMP_NOTIFY_INVALID_MINOR_VERSION, 0, 1,
1);
return -1;
}
/*
* Validate the exchange type. If it's a DOI-specified exchange wait
* until after all payloads have been seen for the validation as the
* SA payload might not yet have been parsed, thus the DOI might be
* unknown.
*/
exch_type = GET_ISAKMP_HDR_EXCH_TYPE(buf);
if (exch_type == ISAKMP_EXCH_NONE ||
(exch_type >= ISAKMP_EXCH_FUTURE_MIN &&
exch_type <= ISAKMP_EXCH_FUTURE_MAX) ||
(setup_isakmp_sa && exch_type >= ISAKMP_EXCH_DOI_MIN)) {
log_print("message_recv: invalid exchange type %s",
constant_name(isakmp_exch_cst, exch_type));
message_drop(msg, ISAKMP_NOTIFY_INVALID_EXCHANGE_TYPE, 0, 1,
1);
return -1;
}
/*
* Check for unrecognized flags, or the encryption flag when we don't
* have an ISAKMP SA to decrypt with.
*/
flags = GET_ISAKMP_HDR_FLAGS(buf);
if (flags & ~(ISAKMP_FLAGS_ENC | ISAKMP_FLAGS_COMMIT |
ISAKMP_FLAGS_AUTH_ONLY)) {
log_print("message_recv: invalid flags 0x%x",
GET_ISAKMP_HDR_FLAGS(buf));
message_drop(msg, ISAKMP_NOTIFY_INVALID_FLAGS, 0, 1, 1);
return -1;
}
/*
* If we are about to setup an ISAKMP SA, the message ID must be
* zero.
*/
msgid_is_zero = zero_test(buf + ISAKMP_HDR_MESSAGE_ID_OFF,
ISAKMP_HDR_MESSAGE_ID_LEN);
if (setup_isakmp_sa && !msgid_is_zero) {
log_print("message_recv: invalid message id");
message_drop(msg, ISAKMP_NOTIFY_INVALID_MESSAGE_ID, 0, 1, 1);
return -1;
}
if (!setup_isakmp_sa && msgid_is_zero) {
/*
* XXX Very likely redundant, look at the else clause of the
* if (setup_isakmp_sa) statement above.
*/
msg->exchange = exchange_lookup(buf, 0);
if (!msg->exchange) {
log_print("message_recv: phase 1 message after "
"ISAKMP SA is ready");
message_free(msg);
return -1;
} else if (msg->exchange->last_sent) {
LOG_DBG((LOG_MESSAGE, 80, "message_recv: resending "
"last message from phase 1"));
message_send(msg->exchange->last_sent);
}
}
if (flags & ISAKMP_FLAGS_ENC) {
if (!msg->isakmp_sa) {
LOG_DBG((LOG_MISC, 10, "message_recv: no isakmp_sa "
"for encrypted message"));
message_free(msg);
return -1;
}
/* Decrypt rest of message using a DOI-specified IV. */
ks = msg->isakmp_sa->doi->get_keystate(msg);
if (!ks) {
message_free(msg);
return -1;
}
msg->orig = malloc(sz);
if (!msg->orig) {
message_free(msg);
free(ks);
return -1;
}
memcpy(msg->orig, buf, sz);
crypto_decrypt(ks, buf + ISAKMP_HDR_SZ, sz - ISAKMP_HDR_SZ);
} else
msg->orig = buf;
msg->orig_sz = sz;
/* IKE packet capture */
message_packet_log(msg);
/*
* Check the overall payload structure at the same time as indexing
* them by type.
*/
if (GET_ISAKMP_HDR_NEXT_PAYLOAD(buf) != ISAKMP_PAYLOAD_NONE &&
message_sort_payloads(msg, GET_ISAKMP_HDR_NEXT_PAYLOAD(buf))) {
free(ks);
return -1;
}
/*
* Run generic payload tests now. If anything fails these checks, the
* message needs either to be retained for later duplicate checks or
* freed entirely.
* XXX Should SAs and even transports be cleaned up then too?
*/
if (message_validate_payloads(msg)) {
free(ks);
return -1;
}
/*
* If we have not found an exchange by now something is definitely
* wrong.
*/
if (!msg->exchange) {
log_print("message_recv: no exchange");
message_drop(msg, ISAKMP_NOTIFY_PAYLOAD_MALFORMED, 0, 1, 1);
free(ks);
return -1;
}
/*
* NAT-T may have switched ports for us. We need to replace the
* old ISAKMP SA transport here with one that contains the proper
* (i.e translated) ports.
*/
if (msg->isakmp_sa && msg->exchange->phase == 1) {
t = msg->isakmp_sa->transport;
msg->isakmp_sa->transport = msg->transport;
transport_reference(msg->transport);
transport_release(t);
}
/*
* Now we can validate DOI-specific exchange types. If we have no SA
* DOI-specific exchange types are definitely wrong.
*/
if (exch_type >= ISAKMP_EXCH_DOI_MIN &&
msg->exchange->doi->validate_exchange(exch_type)) {
log_print("message_recv: invalid DOI exchange type %d",
exch_type);
message_drop(msg, ISAKMP_NOTIFY_INVALID_EXCHANGE_TYPE, 0, 1,
1);
free(ks);
return -1;
}
/* Make sure the IV we used gets saved in the proper SA. */
if (ks) {
if (!msg->exchange->keystate) {
msg->exchange->keystate = ks;
msg->exchange->crypto = ks->xf;
} else
free(ks);
}
/* Handle the flags. */
if (flags & ISAKMP_FLAGS_ENC)
msg->exchange->flags |= EXCHANGE_FLAG_ENCRYPT;
if ((msg->exchange->flags & EXCHANGE_FLAG_COMMITTED) == 0 &&
(flags & ISAKMP_FLAGS_COMMIT))
msg->exchange->flags |= EXCHANGE_FLAG_HE_COMMITTED;
/*
* Except for the 3rd Aggressive Mode message, require encryption
* as soon as we have the keystate for it.
*/
if ((flags & ISAKMP_FLAGS_ENC) == 0 &&
(msg->exchange->phase == 2 ||
(msg->exchange->keystate &&
msg->exchange->type != ISAKMP_EXCH_AGGRESSIVE))) {
log_print("message_recv: cleartext phase %d message",
msg->exchange->phase);
message_drop(msg, ISAKMP_NOTIFY_INVALID_FLAGS, 0, 1, 1);
return -1;
}
/* OK let the exchange logic do the rest. */
exchange_run(msg);
return 0;
}
void
message_send_expire(struct message *msg)
{
msg->retrans = 0;
message_send(msg);
}
/* Queue up message MSG for transmittal. */
void
message_send(struct message *msg)
{
struct exchange *exchange = msg->exchange;
struct message *m;
struct msg_head *q;
/* Remove retransmissions on this message */
if (msg->retrans) {
timer_remove_event(msg->retrans);
msg->retrans = 0;
}
/* IKE packet capture */
message_packet_log(msg);
/*
* If the ISAKMP SA has set up encryption, encrypt the message.
* However, in a retransmit, it is already encrypted.
*/
if ((msg->flags & MSG_ENCRYPTED) == 0 &&
exchange->flags & EXCHANGE_FLAG_ENCRYPT) {
if (!exchange->keystate) {
exchange->keystate = exchange->doi->get_keystate(msg);
if (!exchange->keystate)
return;
exchange->crypto = exchange->keystate->xf;
exchange->flags |= EXCHANGE_FLAG_ENCRYPT;
}
if (message_encrypt(msg)) {
/* XXX Log. */
return;
}
}
/* Keep the COMMIT bit on. */
if (exchange->flags & EXCHANGE_FLAG_COMMITTED)
SET_ISAKMP_HDR_FLAGS(msg->iov[0].iov_base,
GET_ISAKMP_HDR_FLAGS(msg->iov[0].iov_base)
| ISAKMP_FLAGS_COMMIT);
message_dump_raw("message_send", msg, LOG_MESSAGE);
msg->flags |= MSG_IN_TRANSIT;
exchange->in_transit = msg;
/*
* If we get a retransmission of a message before our response
* has left the queue, don't queue it again, as it will result
* in a circular list.
*/
q = msg->transport->vtbl->get_queue(msg);
for (m = TAILQ_FIRST(q); m; m = TAILQ_NEXT(m, link))
if (m == msg) {
LOG_DBG((LOG_MESSAGE, 60,
"message_send: msg %p already on sendq %p", m, q));
return;
}
TAILQ_INSERT_TAIL(q, msg, link);
}
/*
* Setup the ISAKMP message header for message MSG. EXCHANGE is the exchange
* type, FLAGS are the ISAKMP header flags and MSG_ID is message ID
* identifying the exchange.
*/
void
message_setup_header(struct message *msg, u_int8_t exchange, u_int8_t flags,
u_int8_t *msg_id)
{
u_int8_t *buf = msg->iov[0].iov_base;
SET_ISAKMP_HDR_ICOOKIE(buf, msg->exchange->cookies);
SET_ISAKMP_HDR_RCOOKIE(buf, msg->exchange->cookies +
ISAKMP_HDR_ICOOKIE_LEN);
SET_ISAKMP_HDR_NEXT_PAYLOAD(buf, ISAKMP_PAYLOAD_NONE);
SET_ISAKMP_HDR_VERSION(buf, ISAKMP_VERSION_MAKE(1, 0));
SET_ISAKMP_HDR_EXCH_TYPE(buf, exchange);
SET_ISAKMP_HDR_FLAGS(buf, flags);
SET_ISAKMP_HDR_MESSAGE_ID(buf, msg_id);
SET_ISAKMP_HDR_LENGTH(buf, msg->iov[0].iov_len);
}
/*
* Add the payload of type PAYLOAD in BUF sized SZ to the MSG message.
* The caller thereby is released from the responsibility of freeing BUF,
* unless we return a failure of course. If LINK is set the former
* payload's "next payload" field to PAYLOAD.
*
* XXX We might want to resize the iov array several slots at a time.
*/
int
message_add_payload(struct message *msg, u_int8_t payload, u_int8_t *buf,
size_t sz, int link)
{
struct iovec *new_iov;
struct payload *payload_node;
payload_node = calloc(1, sizeof *payload_node);
if (!payload_node) {
log_error("message_add_payload: calloc (1, %lu) failed",
(unsigned long)sizeof *payload_node);
return -1;
}
new_iov = (struct iovec *) realloc(msg->iov, (msg->iovlen + 1) *
sizeof *msg->iov);
if (!new_iov) {
log_error("message_add_payload: realloc (%p, %lu) failed",
msg->iov, (msg->iovlen + 1) *
(unsigned long)sizeof *msg->iov);
free(payload_node);
return -1;
}
msg->iov = new_iov;
new_iov[msg->iovlen].iov_base = buf;
new_iov[msg->iovlen].iov_len = sz;
msg->iovlen++;
if (link)
*msg->nextp = payload;
msg->nextp = buf + ISAKMP_GEN_NEXT_PAYLOAD_OFF;
*msg->nextp = ISAKMP_PAYLOAD_NONE;
SET_ISAKMP_GEN_RESERVED(buf, 0);
SET_ISAKMP_GEN_LENGTH(buf, sz);
SET_ISAKMP_HDR_LENGTH(msg->iov[0].iov_base,
GET_ISAKMP_HDR_LENGTH(msg->iov[0].iov_base) + sz);
/*
* For the sake of exchange_validate we index the payloads even in
* outgoing messages, however context and flags are uninteresting in
* this situation.
*/
payload_node->p = buf;
TAILQ_INSERT_TAIL(&msg->payload[payload], payload_node, link);
return 0;
}
/* XXX Move up when ready. */
struct info_args {
char discr;
u_int32_t doi;
u_int8_t proto;
u_int16_t spi_sz;
union {
struct {
u_int16_t msg_type;
u_int8_t *spi;
} n;
struct {
u_int16_t nspis;
u_int8_t *spis;
} d;
struct {
u_int16_t msg_type;
u_int8_t *spi;
u_int32_t seq;
} dpd;
} u;
};
/*
* As a reaction to the incoming message MSG create an informational exchange
* protected by ISAKMP_SA and send a notify payload of type NOTIFY, with
* fields initialized from SA. INCOMING is true if the SPI field should be
* filled with the incoming SPI and false if it is to be filled with the
* outgoing one.
*
* XXX Should we handle sending multiple notify payloads? The draft allows
* it, but do we need it? Furthermore, should we not return a success
* status value?
*/
void
message_send_notification(struct message *msg, struct sa *isakmp_sa,
u_int16_t notify, struct proto *proto, int incoming)
{
struct info_args args;
struct sa *doi_sa = proto ? proto->sa : isakmp_sa;
args.discr = 'N';
args.doi = doi_sa ? doi_sa->doi->id : ISAKMP_DOI_ISAKMP;
args.proto = proto ? proto->proto : ISAKMP_PROTO_ISAKMP;
args.spi_sz = proto ? proto->spi_sz[incoming] : 0;
args.u.n.msg_type = notify;
args.u.n.spi = proto ? proto->spi[incoming] : 0;
if (isakmp_sa && (isakmp_sa->flags & SA_FLAG_READY))
exchange_establish_p2(isakmp_sa, ISAKMP_EXCH_INFO, 0, &args,
0, 0);
else
exchange_establish_p1(msg->transport, ISAKMP_EXCH_INFO,
msg->exchange ? msg->exchange->doi->id : ISAKMP_DOI_ISAKMP,
0, &args, 0, 0, 0);
}
/* Send a DELETE inside an informational exchange for each protocol in SA. */
void
message_send_delete(struct sa *sa)
{
struct info_args args;
struct proto *proto;
struct sa *isakmp_sa;
struct sockaddr *dst;
if (!sa->transport)
return;
sa->transport->vtbl->get_dst(sa->transport, &dst);
isakmp_sa = sa_isakmp_lookup_by_peer(dst, SA_LEN(dst));
if (!isakmp_sa) {
/*
* XXX We ought to setup an ISAKMP SA with our peer here and
* send the DELETE over that one.
*/
return;
}
args.discr = 'D';
args.doi = sa->doi->id;
args.u.d.nspis = 1;
for (proto = TAILQ_FIRST(&sa->protos); proto;
proto = TAILQ_NEXT(proto, link)) {
switch (proto->proto) {
case ISAKMP_PROTO_ISAKMP:
args.spi_sz = ISAKMP_HDR_COOKIES_LEN;
args.u.d.spis = sa->cookies;
break;
case IPSEC_PROTO_IPSEC_AH:
case IPSEC_PROTO_IPSEC_ESP:
case IPSEC_PROTO_IPCOMP:
args.spi_sz = proto->spi_sz[1];
args.u.d.spis = proto->spi[1];
break;
default:
log_print("message_send_delete: cannot delete unknown "
"protocol %d", proto->proto);
continue;
}
args.proto = proto->proto;
exchange_establish_p2(isakmp_sa, ISAKMP_EXCH_INFO, 0, &args,
0, 0);
}
}
void
message_send_dpd_notify(struct sa* isakmp_sa, u_int16_t notify, u_int32_t seq)
{
struct info_args args;
args.discr = 'P';
args.doi = IPSEC_DOI_IPSEC;
args.proto = ISAKMP_PROTO_ISAKMP;
args.spi_sz = ISAKMP_HDR_COOKIES_LEN;
args.u.dpd.msg_type = notify;
args.u.dpd.spi = isakmp_sa->cookies;
args.u.dpd.seq = htonl(seq);
exchange_establish_p2(isakmp_sa, ISAKMP_EXCH_INFO, 0, &args, 0, 0);
}
/* Build the informational message into MSG. */
int
message_send_info(struct message *msg)
{
u_int8_t *buf;
size_t sz = 0;
struct info_args *args = msg->extra;
u_int8_t payload;
/* Let the DOI get the first hand on the message. */
if (msg->exchange->doi->informational_pre_hook)
if (msg->exchange->doi->informational_pre_hook(msg))
return -1;
switch (args->discr) {
case 'P':
sz = sizeof args->u.dpd.seq;
/* FALLTHROUGH */
case 'N':
sz += ISAKMP_NOTIFY_SPI_OFF + args->spi_sz;
break;
case 'D':
default: /* Silence gcc */
sz = ISAKMP_DELETE_SPI_OFF + args->u.d.nspis * args->spi_sz;
break;
}
buf = calloc(1, sz);
if (!buf) {
log_error("message_send_info: calloc (1, %lu) failed",
(unsigned long)sz);
message_free(msg);
return -1;
}
switch (args->discr) {
case 'P':
memcpy(buf + ISAKMP_NOTIFY_SPI_OFF + args->spi_sz,
&args->u.dpd.seq, sizeof args->u.dpd.seq);
/* FALLTHROUGH */
case 'N':
/* Build the NOTIFY payload. */
payload = ISAKMP_PAYLOAD_NOTIFY;
SET_ISAKMP_NOTIFY_DOI(buf, args->doi);
SET_ISAKMP_NOTIFY_PROTO(buf, args->proto);
SET_ISAKMP_NOTIFY_SPI_SZ(buf, args->spi_sz);
SET_ISAKMP_NOTIFY_MSG_TYPE(buf, args->u.n.msg_type);
memcpy(buf + ISAKMP_NOTIFY_SPI_OFF, args->u.n.spi,
args->spi_sz);
break;
case 'D':
default: /* Silence GCC. */
/* Build the DELETE payload. */
payload = ISAKMP_PAYLOAD_DELETE;
SET_ISAKMP_DELETE_DOI(buf, args->doi);
SET_ISAKMP_DELETE_PROTO(buf, args->proto);
SET_ISAKMP_DELETE_SPI_SZ(buf, args->spi_sz);
SET_ISAKMP_DELETE_NSPIS(buf, args->u.d.nspis);
memcpy(buf + ISAKMP_DELETE_SPI_OFF, args->u.d.spis,
args->u.d.nspis * args->spi_sz);
msg->flags |= MSG_PRIORITIZED;
break;
}
if (message_add_payload(msg, payload, buf, sz, 1)) {
free(buf);
message_free(msg);
return -1;
}
/* Let the DOI get the last hand on the message. */
if (msg->exchange->doi->informational_post_hook)
if (msg->exchange->doi->informational_post_hook(msg)) {
message_free(msg);
return -1;
}
return 0;
}
/*
* Drop the MSG message due to reason given in NOTIFY. If NOTIFY is set
* send out a notification to the originator. Fill this notification with
* values from PROTO. INCOMING decides which SPI to include. If CLEAN is
* set, free the message when ready with it.
*/
void
message_drop(struct message *msg, int notify, struct proto *proto,
int incoming, int clean)
{
struct transport *t = msg->transport;
struct sockaddr *dst;
char *address;
short port = 0;
t->vtbl->get_dst(t, &dst);
if (sockaddr2text(dst, &address, 0)) {
log_error("message_drop: sockaddr2text () failed");
address = 0;
}
switch (dst->sa_family) {
case AF_INET:
port = ((struct sockaddr_in *)dst)->sin_port;
break;
case AF_INET6:
port = ((struct sockaddr_in6 *)dst)->sin6_port;
break;
default:
log_print("message_drop: unknown protocol family %d",
dst->sa_family);
}
log_print("dropped message from %s port %d due to notification type "
"%s", address ? address : "<unknown>", htons(port),
constant_name(isakmp_notify_cst, notify));
free(address);
/* If specified, return a notification. */
if (notify)
message_send_notification(msg, msg->isakmp_sa, notify, proto,
incoming);
if (clean)
message_free(msg);
}
/*
* If the user demands debug printouts, printout MSG with as much detail
* as we can without resorting to per-payload handling.
*/
void
message_dump_raw(char *header, struct message *msg, int class)
{
u_int32_t i, j, k = 0;
char buf[80], *p = buf;
LOG_DBG((class, 70, "%s: message %p", header, msg));
field_dump_payload(isakmp_hdr_fld, msg->iov[0].iov_base);
for (i = 0; i < msg->iovlen; i++)
for (j = 0; j < msg->iov[i].iov_len; j++) {
snprintf(p, sizeof buf - (int) (p - buf), "%02x",
((u_int8_t *) msg->iov[i].iov_base)[j]);
p += strlen(p);
if (++k % 32 == 0) {
*p = '\0';
LOG_DBG((class, 70, "%s: %s", header, buf));
p = buf;
} else if (k % 4 == 0)
*p++ = ' ';
}
*p = '\0';
if (p != buf)
LOG_DBG((class, 70, "%s: %s", header, buf));
}
static void
message_packet_log(struct message *msg)
{
struct sockaddr *src, *dst;
struct transport *t = msg->transport;
/* Don't log retransmissions. Redundant for incoming packets... */
if (msg->xmits > 0)
return;
if (msg->exchange && msg->exchange->flags & EXCHANGE_FLAG_NAT_T_ENABLE)
t = ((struct virtual_transport *)msg->transport)->encap;
/* Figure out direction. */
if (msg->exchange &&
msg->exchange->initiator ^ (msg->exchange->step % 2)) {
t->vtbl->get_src(t, &src);
t->vtbl->get_dst(t, &dst);
} else {
t->vtbl->get_src(t, &dst);
t->vtbl->get_dst(t, &src);
}
log_packet_iov(src, dst, msg->iov, msg->iovlen);
}
/*
* Encrypt an outgoing message MSG. As outgoing messages are represented
* with an iovec with one segment per payload, we need to coalesce them
* into just une buffer containing all payloads and some padding before
* we encrypt.
*/
static int
message_encrypt(struct message *msg)
{
struct exchange *exchange = msg->exchange;
size_t i, sz = 0;
u_int8_t *buf;
/* If no payloads, nothing to do. */
if (msg->iovlen == 1)
return 0;
/*
* For encryption we need to put all payloads together in a single
* buffer. This buffer should be padded to the current crypto
* transform's blocksize.
*/
for (i = 1; i < msg->iovlen; i++)
sz += msg->iov[i].iov_len;
sz = ((sz + exchange->crypto->blocksize - 1) /
exchange->crypto->blocksize) * exchange->crypto->blocksize;
buf = realloc(msg->iov[1].iov_base, sz);
if (!buf) {
log_error("message_encrypt: realloc (%p, %lu) failed",
msg->iov[1].iov_base, (unsigned long) sz);
return -1;
}
msg->iov[1].iov_base = buf;
for (i = 2; i < msg->iovlen; i++) {
memcpy(buf + msg->iov[1].iov_len, msg->iov[i].iov_base,
msg->iov[i].iov_len);
msg->iov[1].iov_len += msg->iov[i].iov_len;
free(msg->iov[i].iov_base);
}
/* Pad with zeroes. */
memset(buf + msg->iov[1].iov_len, '\0', sz - msg->iov[1].iov_len);
msg->iov[1].iov_len = sz;
msg->iovlen = 2;
SET_ISAKMP_HDR_FLAGS(msg->iov[0].iov_base,
GET_ISAKMP_HDR_FLAGS(msg->iov[0].iov_base) | ISAKMP_FLAGS_ENC);
SET_ISAKMP_HDR_LENGTH(msg->iov[0].iov_base, ISAKMP_HDR_SZ + sz);
crypto_encrypt(exchange->keystate, buf, msg->iov[1].iov_len);
msg->flags |= MSG_ENCRYPTED;
/* Update the IV so we can decrypt the next incoming message. */
crypto_update_iv(exchange->keystate);
return 0;
}
/*
* Check whether the message MSG is a duplicate of the last one negotiating
* this specific SA.
*/
static int
message_check_duplicate(struct message *msg)
{
struct exchange *exchange = msg->exchange;
size_t sz = msg->iov[0].iov_len;
u_int8_t *pkt = msg->iov[0].iov_base;
/* If no SA has been found, we cannot test, thus it's good. */
if (!exchange)
return 0;
LOG_DBG((LOG_MESSAGE, 90, "message_check_duplicate: last_received %p",
exchange->last_received));
if (exchange->last_received) {
LOG_DBG_BUF((LOG_MESSAGE, 95,
"message_check_duplicate: last_received",
exchange->last_received->orig,
exchange->last_received->orig_sz));
/* Is it a duplicate, lose the new one. */
if (sz == exchange->last_received->orig_sz &&
memcmp(pkt, exchange->last_received->orig, sz) == 0) {
LOG_DBG((LOG_MESSAGE, 80,
"message_check_duplicate: dropping dup"));
/*
* Retransmit if the previous sent message was the last
* of an exchange, otherwise just wait for the
* ordinary retransmission.
*/
if (exchange->last_sent && (exchange->last_sent->flags
& MSG_LAST))
message_send(exchange->last_sent);
message_free(msg);
return -1;
}
}
/*
* As this new message is an indication that state is moving forward
* at the peer, remove the retransmit timer on our last message.
*/
if (exchange->last_sent) {
if (exchange->last_sent == exchange->in_transit) {
struct message *m = exchange->in_transit;
TAILQ_REMOVE(m->transport->vtbl->get_queue(m), m,
link);
exchange->in_transit = 0;
}
message_free(exchange->last_sent);
exchange->last_sent = 0;
}
return 0;
}
/* Helper to message_negotiate_sa. */
static __inline struct payload *
step_transform(struct payload *tp, struct payload **propp,
struct payload **sap)
{
tp = TAILQ_NEXT(tp, link);
if (tp) {
*propp = tp->context;
*sap = (*propp)->context;
}
return tp;
}
/*
* Pick out the first transforms out of MSG (which should contain at least one
* SA payload) we accept as a full protection suite.
*/
int
message_negotiate_sa(struct message *msg, int (*validate)(struct exchange *,
struct sa *, struct sa *))
{
struct payload *tp, *propp, *sap, *next_tp = 0, *next_propp, *next_sap;
struct payload *saved_tp = 0, *saved_propp = 0, *saved_sap = 0;
struct sa *sa;
struct proto *proto;
int suite_ok_so_far = 0;
struct exchange *exchange = msg->exchange;
/*
* This algorithm is a weird bottom-up thing... mostly due to the
* payload links pointing upwards.
*
* The algorithm goes something like this:
* Foreach transform
* If transform is compatible
* Remember that this protocol can work
* Skip to last transform of this protocol
* If next transform belongs to a new protocol inside the same suite
* If no transform was found for the current protocol
* Forget all earlier transforms for protocols in this suite
* Skip to last transform of this suite
* If next transform belongs to a new suite
* If the current protocol had an OK transform
* Skip to the last transform of this SA
* If the next transform belongs to a new SA
* If no transforms have been chosen
* Issue a NO_PROPOSAL_CHOSEN notification
*/
sa = TAILQ_FIRST(&exchange->sa_list);
for (tp = payload_first(msg, ISAKMP_PAYLOAD_TRANSFORM); tp;
tp = next_tp) {
propp = tp->context;
sap = propp->context;
sap->flags |= PL_MARK;
next_tp = step_transform(tp, &next_propp, &next_sap);
/* For each transform, see if it is compatible. */
if (!attribute_map(tp->p + ISAKMP_TRANSFORM_SA_ATTRS_OFF,
GET_ISAKMP_GEN_LENGTH(tp->p) -
ISAKMP_TRANSFORM_SA_ATTRS_OFF,
exchange->doi->is_attribute_incompatible, msg)) {
LOG_DBG((LOG_NEGOTIATION, 30, "message_negotiate_sa: "
"transform %d proto %d proposal %d ok",
GET_ISAKMP_TRANSFORM_NO(tp->p),
GET_ISAKMP_PROP_PROTO(propp->p),
GET_ISAKMP_PROP_NO(propp->p)));
if (sa_add_transform(sa, tp, exchange->initiator,
&proto))
goto cleanup;
suite_ok_so_far = 1;
saved_tp = next_tp;
saved_propp = next_propp;
saved_sap = next_sap;
/* Skip to last transform of this protocol proposal. */
while ((next_tp = step_transform(tp, &next_propp,
&next_sap)) && next_propp == propp)
tp = next_tp;
}
retry_transform:
/*
* Figure out if we will be looking at a new protocol proposal
* inside the current protection suite.
*/
if (next_tp && propp != next_propp && sap == next_sap &&
(GET_ISAKMP_PROP_NO(propp->p) ==
GET_ISAKMP_PROP_NO(next_propp->p))) {
if (!suite_ok_so_far) {
LOG_DBG((LOG_NEGOTIATION, 30,
"message_negotiate_sa: proto %d proposal "
"%d failed",
GET_ISAKMP_PROP_PROTO(propp->p),
GET_ISAKMP_PROP_NO(propp->p)));
/*
* Remove potentially succeeded choices from
* the SA.
*/
while ((proto = TAILQ_FIRST(&sa->protos)))
TAILQ_REMOVE(&sa->protos, proto, link);
/*
* Skip to the last transform of this
* protection suite.
*/
while ((next_tp = step_transform(tp,
&next_propp, &next_sap)) &&
(GET_ISAKMP_PROP_NO(next_propp->p) ==
GET_ISAKMP_PROP_NO(propp->p)) &&
next_sap == sap)
tp = next_tp;
}
suite_ok_so_far = 0;
}
/*
* Figure out if we will be looking at a new protection
* suite.
*/
if (!next_tp ||
(propp != next_propp && (GET_ISAKMP_PROP_NO(propp->p) !=
GET_ISAKMP_PROP_NO(next_propp->p))) ||
sap != next_sap) {
/*
* Check if the suite we just considered was OK, if so
* we check it against the accepted ones.
*/
if (suite_ok_so_far) {
if (!validate || validate(exchange, sa,
msg->isakmp_sa)) {
LOG_DBG((LOG_NEGOTIATION, 30,
"message_negotiate_sa: proposal "
"%d succeeded",
GET_ISAKMP_PROP_NO(propp->p)));
/*
* Skip to the last transform of this
* SA.
*/
while ((next_tp = step_transform(tp,
&next_propp, &next_sap)) &&
next_sap == sap)
tp = next_tp;
} else {
/* Backtrack. */
LOG_DBG((LOG_NEGOTIATION, 30,
"message_negotiate_sa: proposal "
"%d failed",
GET_ISAKMP_PROP_NO(propp->p)));
next_tp = saved_tp;
next_propp = saved_propp;
next_sap = saved_sap;
suite_ok_so_far = 0;
/*
* Remove potentially succeeded
* choices from the SA.
*/
while ((proto =
TAILQ_FIRST(&sa->protos)))
TAILQ_REMOVE(&sa->protos,
proto, link);
goto retry_transform;
}
}
}
/* Have we walked all the proposals of an SA? */
if (!next_tp || sap != next_sap) {
if (!suite_ok_so_far) {
/*
* XXX We cannot possibly call this a drop...
* seeing we just turn down one of the offers,
* can we? I suggest renaming message_drop to
* something else.
*/
log_print("message_negotiate_sa: no "
"compatible proposal found");
message_drop(msg,
ISAKMP_NOTIFY_NO_PROPOSAL_CHOSEN, 0, 1, 0);
}
sa = TAILQ_NEXT(sa, next);
}
}
return 0;
cleanup:
/*
* Remove potentially succeeded choices from the SA.
* XXX Do we leak struct protos and related data here?
*/
while ((proto = TAILQ_FIRST(&sa->protos)))
TAILQ_REMOVE(&sa->protos, proto, link);
return -1;
}
/*
* Add SA, proposal and transform payload(s) to MSG out of information
* found in the exchange MSG is part of..
*/
int
message_add_sa_payload(struct message *msg)
{
struct exchange *exchange = msg->exchange;
u_int8_t *sa_buf, *saved_nextp_sa, *saved_nextp_prop;
size_t sa_len, extra_sa_len;
int i, nprotos = 0;
struct proto *proto;
u_int8_t **transforms = 0, **proposals = 0;
size_t *transform_lens = 0, *proposal_lens = 0;
struct sa *sa;
struct doi *doi = exchange->doi;
u_int8_t *spi = 0;
size_t spi_sz;
/*
* Generate SA payloads.
*/
for (sa = TAILQ_FIRST(&exchange->sa_list); sa;
sa = TAILQ_NEXT(sa, next)) {
/* Setup a SA payload. */
sa_len = ISAKMP_SA_SIT_OFF + doi->situation_size();
extra_sa_len = 0;
sa_buf = malloc(sa_len);
if (!sa_buf) {
log_error("message_add_sa_payload: "
"malloc (%lu) failed", (unsigned long)sa_len);
goto cleanup;
}
SET_ISAKMP_SA_DOI(sa_buf, doi->id);
doi->setup_situation(sa_buf);
/* Count transforms. */
nprotos = 0;
for (proto = TAILQ_FIRST(&sa->protos); proto;
proto = TAILQ_NEXT(proto, link))
nprotos++;
/*
* Allocate transient transform and proposal payload/size
* vectors.
*/
transforms = calloc(nprotos, sizeof *transforms);
if (!transforms) {
log_error("message_add_sa_payload: calloc (%d, %lu) "
"failed", nprotos,
(unsigned long)sizeof *transforms);
goto cleanup;
}
transform_lens = calloc(nprotos, sizeof *transform_lens);
if (!transform_lens) {
log_error("message_add_sa_payload: calloc (%d, %lu) "
"failed", nprotos,
(unsigned long) sizeof *transform_lens);
goto cleanup;
}
proposals = calloc(nprotos, sizeof *proposals);
if (!proposals) {
log_error("message_add_sa_payload: calloc (%d, %lu) "
"failed", nprotos,
(unsigned long)sizeof *proposals);
goto cleanup;
}
proposal_lens = calloc(nprotos, sizeof *proposal_lens);
if (!proposal_lens) {
log_error("message_add_sa_payload: calloc (%d, %lu) "
"failed", nprotos,
(unsigned long)sizeof *proposal_lens);
goto cleanup;
}
/* Pick out the chosen transforms. */
for (proto = TAILQ_FIRST(&sa->protos), i = 0; proto;
proto = TAILQ_NEXT(proto, link), i++) {
transform_lens[i] =
GET_ISAKMP_GEN_LENGTH(proto->chosen->p);
transforms[i] = malloc(transform_lens[i]);
if (!transforms[i]) {
log_error("message_add_sa_payload: malloc "
"(%lu) failed",
(unsigned long)transform_lens[i]);
goto cleanup;
}
/* Get incoming SPI from application. */
if (doi->get_spi) {
spi = doi->get_spi(&spi_sz,
GET_ISAKMP_PROP_PROTO(proto->chosen->context->p),
msg);
if (spi_sz && !spi)
goto cleanup;
proto->spi[1] = spi;
proto->spi_sz[1] = spi_sz;
} else
spi_sz = 0;
proposal_lens[i] = ISAKMP_PROP_SPI_OFF + spi_sz;
proposals[i] = malloc(proposal_lens[i]);
if (!proposals[i]) {
log_error("message_add_sa_payload: malloc "
"(%lu) failed",
(unsigned long)proposal_lens[i]);
goto cleanup;
}
memcpy(transforms[i], proto->chosen->p,
transform_lens[i]);
memcpy(proposals[i], proto->chosen->context->p,
ISAKMP_PROP_SPI_OFF);
SET_ISAKMP_PROP_NTRANSFORMS(proposals[i], 1);
SET_ISAKMP_PROP_SPI_SZ(proposals[i], spi_sz);
if (spi_sz)
memcpy(proposals[i] + ISAKMP_PROP_SPI_OFF, spi,
spi_sz);
extra_sa_len += proposal_lens[i] + transform_lens[i];
}
/*
* Add the payloads. As this is a SA, we need to recompute the
* lengths of the payloads containing others. We also need to
* reset these payload's "next payload type" field.
*/
if (message_add_payload(msg, ISAKMP_PAYLOAD_SA, sa_buf,
sa_len, 1))
goto cleanup;
SET_ISAKMP_GEN_LENGTH(sa_buf, sa_len + extra_sa_len);
sa_buf = 0;
saved_nextp_sa = msg->nextp;
for (proto = TAILQ_FIRST(&sa->protos), i = 0; proto;
proto = TAILQ_NEXT(proto, link), i++) {
if (message_add_payload(msg, ISAKMP_PAYLOAD_PROPOSAL,
proposals[i], proposal_lens[i], i > 0))
goto cleanup;
SET_ISAKMP_GEN_LENGTH(proposals[i], proposal_lens[i] +
transform_lens[i]);
proposals[i] = 0;
saved_nextp_prop = msg->nextp;
if (message_add_payload(msg, ISAKMP_PAYLOAD_TRANSFORM,
transforms[i], transform_lens[i], 0))
goto cleanup;
msg->nextp = saved_nextp_prop;
transforms[i] = 0;
}
msg->nextp = saved_nextp_sa;
/* Free the temporary allocations made above. */
free(transforms);
free(transform_lens);
free(proposals);
free(proposal_lens);
}
return 0;
cleanup:
free(sa_buf);
for (i = 0; i < nprotos; i++) {
free(transforms[i]);
free(proposals[i]);
}
free(transforms);
free(transform_lens);
free(proposals);
free(proposal_lens);
return -1;
}
/*
* Return a copy of MSG's constants starting from OFFSET and stash the size
* in SZP. It is the callers responsibility to free this up.
*/
u_int8_t *
message_copy(struct message *msg, size_t offset, size_t *szp)
{
int skip = 0;
size_t i, sz = 0;
ssize_t start = -1;
u_int8_t *buf, *p;
/* Calculate size of message and where we want to start to copy. */
for (i = 1; i < msg->iovlen; i++) {
sz += msg->iov[i].iov_len;
if (sz <= offset)
skip = i;
else if (start < 0)
start = offset - (sz - msg->iov[i].iov_len);
}
/* Allocate and copy. */
*szp = sz - offset;
buf = malloc(*szp);
if (!buf)
return 0;
p = buf;
for (i = skip + 1; i < msg->iovlen; i++) {
memcpy(p, (u_int8_t *) msg->iov[i].iov_base + start,
msg->iov[i].iov_len - start);
p += msg->iov[i].iov_len - start;
start = 0;
}
return buf;
}
/* Register a post-send function POST_SEND with message MSG. */
int
message_register_post_send(struct message *msg,
void (*post_send)(struct message *))
{
struct post_send *node;
node = malloc(sizeof *node);
if (!node)
return -1;
node->func = post_send;
TAILQ_INSERT_TAIL(&msg->post_send, node, link);
return 0;
}
/* Run the post-send functions of message MSG. */
void
message_post_send(struct message *msg)
{
struct post_send *node;
while ((node = TAILQ_FIRST(&msg->post_send)) != 0) {
TAILQ_REMOVE(&msg->post_send, node, link);
node->func(msg);
free(node);
}
}
struct payload *
payload_first(struct message *msg, u_int8_t payload)
{
return TAILQ_FIRST(&msg->payload[payload]);
}