/*
* Accept a set of transforms offered by the initiator and chose one we can
* handle.
*/
int
ike_phase_1_responder_recv_SA (struct message *msg)
{
struct exchange *exchange = msg->exchange;
struct sa *sa = TAILQ_FIRST (&exchange->sa_list);
struct ipsec_sa *isa = sa->data;
struct payload *sa_p = TAILQ_FIRST (&msg->payload[ISAKMP_PAYLOAD_SA]);
struct payload *prop = TAILQ_FIRST (&msg->payload[ISAKMP_PAYLOAD_PROPOSAL]);
struct ipsec_exch *ie = exchange->data;
/* Mark the SA as handled. */
sa_p->flags |= PL_MARK;
/* IKE requires that only one SA with only one proposal exists. */
if (TAILQ_NEXT (sa_p, link) || TAILQ_NEXT (prop, link))
{
log_print ("ike_phase_1_responder_recv_SA: "
"multiple SA or proposal payloads in phase 1");
/* XXX Is there a better notification type? */
message_drop (msg, ISAKMP_NOTIFY_PAYLOAD_MALFORMED, 0, 1, 0);
return -1;
}
/* Chose a transform from the SA. */
if (message_negotiate_sa (msg, ike_phase_1_validate_prop)
|| !TAILQ_FIRST (&sa->protos))
return -1;
/* XXX Move into message_negotiate_sa? */
ipsec_decode_transform (msg, sa, TAILQ_FIRST (&sa->protos),
TAILQ_FIRST (&sa->protos)->chosen->p);
ie->group = group_get (isa->group_desc);
/*
* Check that the mandatory attributes: encryption, hash, authentication
* method and Diffie-Hellman group description, has been supplied.
*/
if (!exchange->crypto || !ie->hash || !ie->ike_auth || !ie->group)
{
message_drop (msg, ISAKMP_NOTIFY_PAYLOAD_MALFORMED, 0, 1, 0);
return -1;
}
/* Save the body for later hash computation. */
ie->sa_i_b_len = GET_ISAKMP_GEN_LENGTH (sa_p->p) - ISAKMP_GEN_SZ;
ie->sa_i_b = malloc (ie->sa_i_b_len);
if (!ie->sa_i_b)
{
/* XXX How to notify peer? */
log_error ("ike_phase_1_responder_recv_SA: malloc (%lu) failed",
(unsigned long)ie->sa_i_b_len);
return -1;
}
memcpy (ie->sa_i_b, sa_p->p + ISAKMP_GEN_SZ, ie->sa_i_b_len);
return 0;
}
int
cfg_verify_hash(struct message *msg)
{
struct payload *hashp = payload_first(msg, ISAKMP_PAYLOAD_HASH);
struct ipsec_sa *isa = msg->isakmp_sa->data;
struct prf *prf;
u_int8_t *hash, *comp_hash;
size_t hash_len;
if (!hashp) {
log_print("cfg_verify_hash: phase 2 message missing HASH");
message_drop(msg, ISAKMP_NOTIFY_INVALID_HASH_INFORMATION,
0, 1, 0);
return -1;
}
hash = hashp->p;
hash_len = GET_ISAKMP_GEN_LENGTH(hash);
comp_hash = malloc(hash_len - ISAKMP_GEN_SZ);
if (!comp_hash) {
log_error("cfg_verify_hash: malloc (%lu) failed",
(unsigned long)hash_len - ISAKMP_GEN_SZ);
return -1;
}
/* Verify hash. */
prf = prf_alloc(isa->prf_type, isa->hash, isa->skeyid_a,
isa->skeyid_len);
if (!prf) {
free(comp_hash);
return -1;
}
prf->Init(prf->prfctx);
prf->Update(prf->prfctx, msg->exchange->message_id,
ISAKMP_HDR_MESSAGE_ID_LEN);
prf->Update(prf->prfctx, hash + hash_len,
msg->iov[0].iov_len - ISAKMP_HDR_SZ - hash_len);
prf->Final(comp_hash, prf->prfctx);
prf_free(prf);
if (memcmp(hash + ISAKMP_GEN_SZ, comp_hash, hash_len - ISAKMP_GEN_SZ)
!= 0) {
message_drop(msg, ISAKMP_NOTIFY_INVALID_HASH_INFORMATION,
0, 1, 0);
free(comp_hash);
return -1;
}
free(comp_hash);
/* Mark the HASH as handled. */
hashp->flags |= PL_MARK;
/* Mark message authenticated. */
msg->flags |= MSG_AUTHENTICATED;
return 0;
}
/* Receive HASH and check that the exchange has been consistent. */
int
ike_phase_1_recv_AUTH (struct message *msg)
{
struct exchange *exchange = msg->exchange;
struct ipsec_exch *ie = exchange->data;
struct prf *prf;
struct hash *hash = ie->hash;
char header[80];
size_t hashsize = hash->hashsize;
int initiator = exchange->initiator;
u_int8_t **hash_p, *id;
size_t id_len;
/* Choose the right fields to fill in */
hash_p = initiator ? &ie->hash_r : &ie->hash_i;
id = initiator ? exchange->id_r : exchange->id_i;
id_len = initiator ? exchange->id_r_len : exchange->id_i_len;
/* The decoded hash will be in ie->hash_r or ie->hash_i */
if (ie->ike_auth->decode_hash (msg))
{
message_drop (msg, ISAKMP_NOTIFY_INVALID_ID_INFORMATION, 0, 1, 0);
return -1;
}
/* Allocate the prf and start calculating his HASH. */
prf = prf_alloc (ie->prf_type, hash->type, ie->skeyid, ie->skeyid_len);
if (!prf)
{
/* XXX Log? */
return -1;
}
prf->Init (prf->prfctx);
prf->Update (prf->prfctx, initiator ? ie->g_xr : ie->g_xi, ie->g_x_len);
prf->Update (prf->prfctx, initiator ? ie->g_xi : ie->g_xr, ie->g_x_len);
prf->Update (prf->prfctx,
exchange->cookies
+ (initiator ? ISAKMP_HDR_RCOOKIE_OFF : ISAKMP_HDR_ICOOKIE_OFF),
ISAKMP_HDR_ICOOKIE_LEN);
prf->Update (prf->prfctx,
exchange->cookies
+ (initiator ? ISAKMP_HDR_ICOOKIE_OFF : ISAKMP_HDR_RCOOKIE_OFF),
ISAKMP_HDR_ICOOKIE_LEN);
prf->Update (prf->prfctx, ie->sa_i_b, ie->sa_i_b_len);
prf->Update (prf->prfctx, id, id_len);
prf->Final (hash->digest, prf->prfctx);
prf_free (prf);
snprintf (header, sizeof header, "ike_phase_1_recv_AUTH: computed HASH_%c",
initiator ? 'R' : 'I');
LOG_DBG_BUF ((LOG_NEGOTIATION, 80, header, hash->digest, hashsize));
/* Check that the hash we got matches the one we computed. */
if (memcmp (*hash_p, hash->digest, hashsize) != 0)
{
/* XXX Log? */
return -1;
}
return 0;
}
static int
isakmp_responder(struct message *msg)
{
struct payload *p;
u_int16_t type;
switch (msg->exchange->type) {
case ISAKMP_EXCH_INFO:
for (p = payload_first(msg, ISAKMP_PAYLOAD_NOTIFY); p;
p = TAILQ_NEXT(p, link)) {
type = GET_ISAKMP_NOTIFY_MSG_TYPE(p->p);
LOG_DBG((LOG_EXCHANGE, 10, "isakmp_responder: "
"got NOTIFY of type %s",
constant_name(isakmp_notify_cst,
type)));
switch (type) {
case ISAKMP_NOTIFY_STATUS_DPD_R_U_THERE:
case ISAKMP_NOTIFY_STATUS_DPD_R_U_THERE_ACK:
dpd_handle_notify(msg, p);
break;
default:
p->flags |= PL_MARK;
break;
}
}
for (p = payload_first(msg, ISAKMP_PAYLOAD_DELETE); p;
p = TAILQ_NEXT(p, link)) {
LOG_DBG((LOG_EXCHANGE, 10,
"isakmp_responder: got DELETE, ignoring"));
p->flags |= PL_MARK;
}
return 0;
case ISAKMP_EXCH_TRANSACTION:
/* return 0 isakmp_cfg_responder (msg); */
default:
/* XXX So far we don't accept any proposals. */
if (payload_first(msg, ISAKMP_PAYLOAD_SA)) {
message_drop(msg, ISAKMP_NOTIFY_NO_PROPOSAL_CHOSEN,
0, 1, 0);
return -1;
}
}
return 0;
}
/* Figure out what transform the responder chose. */
int
ike_phase_1_initiator_recv_SA (struct message *msg)
{
struct exchange *exchange = msg->exchange;
struct sa *sa = TAILQ_FIRST (&exchange->sa_list);
struct ipsec_exch *ie = exchange->data;
struct ipsec_sa *isa = sa->data;
struct payload *sa_p = TAILQ_FIRST (&msg->payload[ISAKMP_PAYLOAD_SA]);
struct payload *prop = TAILQ_FIRST (&msg->payload[ISAKMP_PAYLOAD_PROPOSAL]);
struct payload *xf = TAILQ_FIRST (&msg->payload[ISAKMP_PAYLOAD_TRANSFORM]);
/*
* IKE requires that only one SA with only one proposal exists and since
* we are getting an answer on our transform offer, only one transform.
*/
if (TAILQ_NEXT (sa_p, link) || TAILQ_NEXT (prop, link)
|| TAILQ_NEXT (xf, link))
{
log_print ("ike_phase_1_initiator_recv_SA: "
"multiple SA, proposal or transform payloads in phase 1");
/* XXX Is there a better notification type? */
message_drop (msg, ISAKMP_NOTIFY_PAYLOAD_MALFORMED, 0, 1, 0);
return -1;
}
/* Check that the chosen transform matches an offer. */
if (message_negotiate_sa (msg, ike_phase_1_validate_prop)
|| !TAILQ_FIRST (&sa->protos))
return -1;
ipsec_decode_transform (msg, sa, TAILQ_FIRST (&sa->protos), xf->p);
/* XXX I don't like exchange-specific stuff in here. */
if (exchange->type != ISAKMP_EXCH_AGGRESSIVE)
ie->group = group_get (isa->group_desc);
/* Mark the SA as handled. */
sa_p->flags |= PL_MARK;
return 0;
}
/*
* As "the server", this starts REQ/REPLY (initiated by the client).
* As "the client", this starts SET/ACK (initiated by the server).
*/
static int
cfg_responder_recv_ATTR(struct message *msg)
{
struct payload *attrp = payload_first(msg, ISAKMP_PAYLOAD_ATTRIBUTE);
struct ipsec_exch *ie = msg->exchange->data;
struct sa *isakmp_sa = msg->isakmp_sa;
struct isakmp_cfg_attr *attr;
struct sockaddr *sa;
char *addr;
if (msg->exchange->phase == 2)
if (cfg_verify_hash(msg))
return -1;
ie->cfg_id = GET_ISAKMP_ATTRIBUTE_ID(attrp->p);
ie->cfg_type = attrp->p[ISAKMP_ATTRIBUTE_TYPE_OFF];
switch (ie->cfg_type) {
case ISAKMP_CFG_REQUEST:
case ISAKMP_CFG_SET:
break;
default:
message_drop(msg, ISAKMP_NOTIFY_PAYLOAD_MALFORMED, 0, 1, 0);
log_print("cfg_responder_recv_ATTR: "
"unexpected configuration message type %d", ie->cfg_type);
return -1;
}
attribute_map(attrp->p + ISAKMP_ATTRIBUTE_ATTRS_OFF,
GET_ISAKMP_GEN_LENGTH(attrp->p) - ISAKMP_TRANSFORM_SA_ATTRS_OFF,
cfg_decode_attribute, ie);
switch (ie->cfg_type) {
case ISAKMP_CFG_REQUEST:
/* We're done. */
break;
case ISAKMP_CFG_SET: {
/* SET/ACK -- Client side (SET from server) */
const char *uk_addr = "<unknown>";
msg->transport->vtbl->get_dst(isakmp_sa->transport,
&sa);
if (sockaddr2text(sa, &addr, 0) < 0)
addr = (char *) uk_addr;
for (attr = LIST_FIRST(&ie->attrs); attr;
attr = LIST_NEXT(attr, link))
LOG_DBG((LOG_NEGOTIATION, 50,
"cfg_responder_recv_ATTR: "
"server %s asks us to SET attribute %s",
addr, constant_name(isakmp_cfg_attr_cst,
attr->type)));
/*
* XXX Here's the place to add code to walk through
* XXX each attribute and send them along to dhclient
* XXX or whatever. Each attribute that we act upon
* XXX (such as setting a netmask), should be marked
* XXX like this for us to send the proper ACK
* XXX response: attr->attr_used++;
*/
if (addr != uk_addr)
free(addr);
}
break;
default:
break;
}
attrp->flags |= PL_MARK;
return 0;
}
/*
* As "the server", this ends SET/ACK.
* As "the client", this ends REQ/REPLY.
*/
static int
cfg_initiator_recv_ATTR(struct message *msg)
{
struct payload *attrp = payload_first(msg, ISAKMP_PAYLOAD_ATTRIBUTE);
struct ipsec_exch *ie = msg->exchange->data;
struct sa *isakmp_sa = msg->isakmp_sa;
struct isakmp_cfg_attr *attr;
struct sockaddr *sa;
const char *uk_addr = "<unknown>";
char *addr;
if (msg->exchange->phase == 2)
if (cfg_verify_hash(msg))
return -1;
/* Sanity. */
if (ie->cfg_id != GET_ISAKMP_ATTRIBUTE_ID(attrp->p)) {
log_print("cfg_initiator_recv_ATTR: "
"cfg packet ID does not match!");
message_drop(msg, ISAKMP_NOTIFY_PAYLOAD_MALFORMED, 0, 1, 0);
return -1;
}
switch (attrp->p[ISAKMP_ATTRIBUTE_TYPE_OFF]) {
case ISAKMP_CFG_ACK:
if (ie->cfg_type != ISAKMP_CFG_SET) {
log_print("cfg_initiator_recv_ATTR: "
"bad packet type ACK");
message_drop(msg, ISAKMP_NOTIFY_PAYLOAD_MALFORMED,
0, 1, 0);
return -1;
}
break;
case ISAKMP_CFG_REPLY:
if (ie->cfg_type != ISAKMP_CFG_REQUEST) {
log_print("cfg_initiator_recv_ATTR: "
"bad packet type REPLY");
message_drop(msg, ISAKMP_NOTIFY_PAYLOAD_MALFORMED,
0, 1, 0);
return -1;
}
break;
default:
log_print("cfg_initiator_recv_ATTR: unexpected configuration "
"message type %d", attrp->p[ISAKMP_ATTRIBUTE_TYPE_OFF]);
message_drop(msg, ISAKMP_NOTIFY_PAYLOAD_MALFORMED, 0, 1, 0);
return -1;
}
attribute_map(attrp->p + ISAKMP_ATTRIBUTE_ATTRS_OFF,
GET_ISAKMP_GEN_LENGTH(attrp->p) - ISAKMP_TRANSFORM_SA_ATTRS_OFF,
cfg_decode_attribute, ie);
switch (ie->cfg_type) {
case ISAKMP_CFG_ACK: {
/* SET/ACK -- Server side (ACK from client) */
msg->transport->vtbl->get_src(isakmp_sa->transport,
&sa);
if (sockaddr2text(sa, &addr, 0) < 0)
addr = (char *) uk_addr;
for (attr = LIST_FIRST(&ie->attrs); attr;
attr = LIST_NEXT(attr, link))
LOG_DBG((LOG_NEGOTIATION, 50,
"cfg_initiator_recv_ATTR: "
"client %s ACKs attribute %s", addr,
constant_name(isakmp_cfg_attr_cst,
attr->type)));
if (addr != uk_addr)
free(addr);
}
break;
case ISAKMP_CFG_REPLY: {
/*
* REQ/REPLY: effect attributes we've gotten
* responses on.
*/
msg->transport->vtbl->get_src(isakmp_sa->transport,
&sa);
if (sockaddr2text(sa, &addr, 0) < 0)
addr = (char *) uk_addr;
for (attr = LIST_FIRST(&ie->attrs); attr;
attr = LIST_NEXT(attr, link))
LOG_DBG((LOG_NEGOTIATION, 50,
"cfg_initiator_recv_ATTR: "
"server %s replied with attribute %s",
addr, constant_name(isakmp_cfg_attr_cst,
attr->type)));
if (addr != uk_addr)
free(addr);
}
break;
default:
break;
}
attrp->flags |= PL_MARK;
return 0;
}
