OpenBSD-4.6/sbin/isakmpd/sa.c
/* $OpenBSD: sa.c,v 1.113 2007/09/02 15:19:24 deraadt Exp $ */
/* $EOM: sa.c,v 1.112 2000/12/12 00:22:52 niklas Exp $ */
/*
* Copyright (c) 1998, 1999, 2000, 2001 Niklas Hallqvist. All rights reserved.
* Copyright (c) 1999, 2001 Angelos D. Keromytis. All rights reserved.
* Copyright (c) 2003, 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 <stdlib.h>
#include <string.h>
#include <netdb.h>
#include <regex.h>
#include <keynote.h>
#include "sysdep.h"
#include "attribute.h"
#include "conf.h"
#include "connection.h"
#include "cookie.h"
#include "doi.h"
#include "exchange.h"
#include "isakmp.h"
#include "log.h"
#include "message.h"
#include "monitor.h"
#include "sa.h"
#include "timer.h"
#include "transport.h"
#include "util.h"
#include "cert.h"
#include "policy.h"
#include "key.h"
#include "ipsec.h"
#include "ipsec_num.h"
/* Initial number of bits from the cookies used as hash. */
#define INITIAL_BUCKET_BITS 6
/*
* Don't try to use more bits than this as a hash.
* We only XOR 16 bits so going above that means changing the code below
* too.
*/
#define MAX_BUCKET_BITS 16
#if 0
static void sa_resize(void);
#endif
static void sa_soft_expire(void *);
static void sa_hard_expire(void *);
static LIST_HEAD(sa_list, sa) *sa_tab;
/* Works both as a maximum index and a mask. */
static int bucket_mask;
void
sa_init(void)
{
int i;
bucket_mask = (1 << INITIAL_BUCKET_BITS) - 1;
sa_tab = calloc(bucket_mask + 1, sizeof(struct sa_list));
if (!sa_tab)
log_fatal("sa_init: malloc (%lu) failed",
(bucket_mask + 1) * (unsigned long)sizeof(struct sa_list));
for (i = 0; i <= bucket_mask; i++)
LIST_INIT(&sa_tab[i]);
}
#if 0
/* XXX We don't yet resize. */
static void
sa_resize(void)
{
int new_mask = (bucket_mask + 1) * 2 - 1;
int i;
struct sa_list *new_tab;
new_tab = realloc(sa_tab, (new_mask + 1) * sizeof(struct sa_list));
if (!new_tab)
return;
sa_tab = new_tab;
for (i = bucket_mask + 1; i <= new_mask; i++)
LIST_INIT(&sa_tab[i]);
bucket_mask = new_mask;
/* XXX Rehash existing entries. */
}
#endif
/* Lookup an SA with the help from a user-supplied checking function. */
struct sa *
sa_find(int (*check) (struct sa*, void *), void *arg)
{
int i;
struct sa *sa;
for (i = 0; i <= bucket_mask; i++)
for (sa = LIST_FIRST(&sa_tab[i]); sa; sa = LIST_NEXT(sa, link))
if (check(sa, arg)) {
LOG_DBG((LOG_SA, 90, "sa_find: return SA %p",
sa));
return sa;
}
LOG_DBG((LOG_SA, 90, "sa_find: no SA matched query"));
return 0;
}
/* Check if SA is an ISAKMP SA with an initiator cookie equal to ICOOKIE. */
static int
sa_check_icookie(struct sa *sa, void *icookie)
{
return sa->phase == 1 &&
memcmp(sa->cookies, icookie, ISAKMP_HDR_ICOOKIE_LEN) == 0;
}
/* Lookup an ISAKMP SA out of just the initiator cookie. */
struct sa *
sa_lookup_from_icookie(u_int8_t *cookie)
{
return sa_find(sa_check_icookie, cookie);
}
struct name_phase_arg {
char *name;
u_int8_t phase;
};
/* Check if SA has the name and phase given by V_ARG. */
static int
sa_check_name_phase(struct sa *sa, void *v_arg)
{
struct name_phase_arg *arg = v_arg;
return sa->name && strcasecmp(sa->name, arg->name) == 0 &&
sa->phase == arg->phase && !(sa->flags & SA_FLAG_REPLACED);
}
/* Lookup an SA by name, case-independent, and phase. */
struct sa *
sa_lookup_by_name(char *name, int phase)
{
struct name_phase_arg arg;
arg.name = name;
arg.phase = phase;
return sa_find(sa_check_name_phase, &arg);
}
struct addr_arg {
struct sockaddr *addr;
socklen_t len;
int phase;
int flags;
};
/*
* Check if SA is ready and has a peer with an address equal the one given
* by V_ADDR. Furthermore if we are searching for a specific phase, check
* that too.
*/
static int
sa_check_peer(struct sa *sa, void *v_addr)
{
struct addr_arg *addr = v_addr;
struct sockaddr *dst;
if (!sa->transport || (sa->flags & SA_FLAG_READY) == 0 ||
(addr->phase && addr->phase != sa->phase))
return 0;
sa->transport->vtbl->get_dst(sa->transport, &dst);
return (net_addrcmp(dst, addr->addr) == 0);
}
struct dst_isakmpspi_arg {
struct sockaddr *dst;
u_int8_t *spi; /* must be ISAKMP_SPI_SIZE octets */
};
/*
* Check if SA matches what we are asking for through V_ARG. It has to
* be a finished phase 1 (ISAKMP) SA.
*/
static int
isakmp_sa_check(struct sa *sa, void *v_arg)
{
struct dst_isakmpspi_arg *arg = v_arg;
struct sockaddr *dst, *src;
if (sa->phase != 1 || !(sa->flags & SA_FLAG_READY))
return 0;
/* verify address is either src or dst for this sa */
sa->transport->vtbl->get_dst(sa->transport, &dst);
sa->transport->vtbl->get_src(sa->transport, &src);
if (memcmp(src, arg->dst, SA_LEN(src)) &&
memcmp(dst, arg->dst, SA_LEN(dst)))
return 0;
/* match icookie+rcookie against spi */
if (memcmp(sa->cookies, arg->spi, ISAKMP_HDR_COOKIES_LEN) == 0)
return 1;
return 0;
}
/*
* Find an ISAKMP SA with a "name" of DST & SPI.
*/
struct sa *
sa_lookup_isakmp_sa(struct sockaddr *dst, u_int8_t *spi)
{
struct dst_isakmpspi_arg arg;
arg.dst = dst;
arg.spi = spi;
return sa_find(isakmp_sa_check, &arg);
}
/* Lookup a ready SA by the peer's address. */
struct sa *
sa_lookup_by_peer(struct sockaddr *dst, socklen_t dstlen, int phase)
{
struct addr_arg arg;
arg.addr = dst;
arg.len = dstlen;
arg.phase = phase;
return sa_find(sa_check_peer, &arg);
}
/* Lookup a ready ISAKMP SA given its peer address. */
struct sa *
sa_isakmp_lookup_by_peer(struct sockaddr *dst, socklen_t dstlen)
{
struct addr_arg arg;
arg.addr = dst;
arg.len = dstlen;
arg.phase = 1;
return sa_find(sa_check_peer, &arg);
}
int
sa_enter(struct sa *sa)
{
u_int16_t bucket = 0;
int i;
u_int8_t *cp;
/* XXX We might resize if we are crossing a certain threshold */
for (i = 0; i < ISAKMP_HDR_COOKIES_LEN; i += 2) {
cp = sa->cookies + i;
/* Doing it this way avoids alignment problems. */
bucket ^= cp[0] | cp[1] << 8;
}
for (i = 0; i < ISAKMP_HDR_MESSAGE_ID_LEN; i += 2) {
cp = sa->message_id + i;
/* Doing it this way avoids alignment problems. */
bucket ^= cp[0] | cp[1] << 8;
}
bucket &= bucket_mask;
LIST_INSERT_HEAD(&sa_tab[bucket], sa, link);
sa_reference(sa);
LOG_DBG((LOG_SA, 70, "sa_enter: SA %p added to SA list", sa));
return 1;
}
/*
* Lookup the SA given by the header fields MSG. PHASE2 is false when
* looking for phase 1 SAa and true otherwise.
*/
struct sa *
sa_lookup_by_header(u_int8_t *msg, int phase2)
{
return sa_lookup(msg + ISAKMP_HDR_COOKIES_OFF,
phase2 ? msg + ISAKMP_HDR_MESSAGE_ID_OFF : 0);
}
/*
* Lookup the SA given by the COOKIES and possibly the MESSAGE_ID unless
* a null pointer, meaning we are looking for phase 1 SAs.
*/
struct sa *
sa_lookup(u_int8_t *cookies, u_int8_t *message_id)
{
u_int16_t bucket = 0;
int i;
struct sa *sa;
u_int8_t *cp;
/*
* We use the cookies to get bits to use as an index into sa_tab, as at
* least one (our cookie) is a good hash, xoring all the bits, 16 at a
* time, and then masking, should do. Doing it this way means we can
* validate cookies very fast thus delimiting the effects of "Denial of
* service"-attacks using packet flooding.
*/
for (i = 0; i < ISAKMP_HDR_COOKIES_LEN; i += 2) {
cp = cookies + i;
/* Doing it this way avoids alignment problems. */
bucket ^= cp[0] | cp[1] << 8;
}
if (message_id)
for (i = 0; i < ISAKMP_HDR_MESSAGE_ID_LEN; i += 2) {
cp = message_id + i;
/* Doing it this way avoids alignment problems. */
bucket ^= cp[0] | cp[1] << 8;
}
bucket &= bucket_mask;
for (sa = LIST_FIRST(&sa_tab[bucket]);
sa && (memcmp(cookies, sa->cookies, ISAKMP_HDR_COOKIES_LEN) != 0 ||
(message_id && memcmp(message_id, sa->message_id,
ISAKMP_HDR_MESSAGE_ID_LEN) != 0) ||
(!message_id && !zero_test(sa->message_id, ISAKMP_HDR_MESSAGE_ID_LEN)));
sa = LIST_NEXT(sa, link))
;
return sa;
}
/* Create an SA. */
int
sa_create(struct exchange *exchange, struct transport *t)
{
struct sa *sa;
/*
* We want the SA zeroed for sa_free to be able to find out what fields
* have been filled-in.
*/
sa = calloc(1, sizeof *sa);
if (!sa) {
log_error("sa_create: calloc (1, %lu) failed",
(unsigned long)sizeof *sa);
return -1;
}
sa->transport = t;
if (t)
transport_reference(t);
sa->phase = exchange->phase;
memcpy(sa->cookies, exchange->cookies, ISAKMP_HDR_COOKIES_LEN);
memcpy(sa->message_id, exchange->message_id,
ISAKMP_HDR_MESSAGE_ID_LEN);
sa->doi = exchange->doi;
sa->policy_id = -1;
if (sa->doi->sa_size) {
/*
* Allocate the DOI-specific structure and initialize it to
* zeroes.
*/
sa->data = calloc(1, sa->doi->sa_size);
if (!sa->data) {
log_error("sa_create: calloc (1, %lu) failed",
(unsigned long)sa->doi->sa_size);
free(sa);
return -1;
}
}
TAILQ_INIT(&sa->protos);
sa_enter(sa);
TAILQ_INSERT_TAIL(&exchange->sa_list, sa, next);
sa_reference(sa);
LOG_DBG((LOG_SA, 60,
"sa_create: sa %p phase %d added to exchange %p (%s)", sa,
sa->phase, exchange,
exchange->name ? exchange->name : "<unnamed>"));
return 0;
}
/*
* Dump the internal state of SA to the report channel, with HEADER
* prepended to each line.
*/
void
sa_dump(int cls, int level, char *header, struct sa *sa)
{
struct proto *proto;
char spi_header[80];
int i;
LOG_DBG((cls, level, "%s: %p %s phase %d doi %d flags 0x%x", header,
sa, sa->name ? sa->name : "<unnamed>", sa->phase, sa->doi->id,
sa->flags));
LOG_DBG((cls, level, "%s: icookie %08x%08x rcookie %08x%08x", header,
decode_32(sa->cookies), decode_32(sa->cookies + 4),
decode_32(sa->cookies + 8), decode_32(sa->cookies + 12)));
LOG_DBG((cls, level, "%s: msgid %08x refcnt %d", header,
decode_32(sa->message_id), sa->refcnt));
LOG_DBG((cls, level, "%s: life secs %llu kb %llu", header, sa->seconds,
sa->kilobytes));
for (proto = TAILQ_FIRST(&sa->protos); proto;
proto = TAILQ_NEXT(proto, link)) {
LOG_DBG((cls, level, "%s: suite %d proto %d", header,
proto->no, proto->proto));
LOG_DBG((cls, level,
"%s: spi_sz[0] %d spi[0] %p spi_sz[1] %d spi[1] %p",
header, proto->spi_sz[0], proto->spi[0], proto->spi_sz[1],
proto->spi[1]));
LOG_DBG((cls, level, "%s: %s, %s", header,
!sa->doi ? "<nodoi>" :
sa->doi->decode_ids("initiator id: %s, responder id: %s",
sa->id_i, sa->id_i_len,
sa->id_r, sa->id_r_len, 0),
!sa->transport ? "<no transport>" :
sa->transport->vtbl->decode_ids(sa->transport)));
for (i = 0; i < 2; i++)
if (proto->spi[i]) {
snprintf(spi_header, sizeof spi_header,
"%s: spi[%d]", header, i);
LOG_DBG_BUF((cls, level, spi_header,
proto->spi[i], proto->spi_sz[i]));
}
}
}
/*
* Display the SA's two SPI values.
*/
static void
report_spi(FILE *fd, const u_int8_t *buf, size_t sz, int spi)
{
#define SBUFSZ (2 * 32 + 9)
char s[SBUFSZ];
size_t i, j;
for (i = j = 0; i < sz;) {
snprintf(s + j, sizeof s - j, "%02x", buf[i++]);
j += strlen(s + j);
if (i % 4 == 0) {
if (i % 32 == 0) {
s[j] = '\0';
fprintf(fd, "%s", s);
j = 0;
} else
s[j++] = ' ';
}
}
if (j) {
s[j] = '\0';
fprintf(fd, "SPI %d: %s\n", spi, s);
}
}
/*
* Display the transform names to file.
* Structure is taken from pf_key_v2.c, pf_key_v2_set_spi.
* Transform names are taken from /usr/src/sys/crypto/xform.c.
*/
static void
report_proto(FILE *fd, struct proto *proto)
{
struct ipsec_proto *iproto;
int keylen, hashlen;
switch (proto->proto) {
case IPSEC_PROTO_IPSEC_ESP:
keylen = ipsec_esp_enckeylength(proto);
hashlen = ipsec_esp_authkeylength(proto);
fprintf(fd, "Transform: IPsec ESP\n");
fprintf(fd, "Encryption key length: %d\n", keylen);
fprintf(fd, "Authentication key length: %d\n", hashlen);
fprintf(fd, "Encryption algorithm: ");
switch (proto->id) {
case IPSEC_ESP_DES:
case IPSEC_ESP_DES_IV32:
case IPSEC_ESP_DES_IV64:
fprintf(fd, "DES\n");
break;
case IPSEC_ESP_3DES:
fprintf(fd, "3DES\n");
break;
case IPSEC_ESP_AES:
fprintf(fd, "AES-128 (CBC)\n");
break;
case IPSEC_ESP_AES_128_CTR:
fprintf(fd, "AES-128 (CTR)\n");
break;
case IPSEC_ESP_CAST:
fprintf(fd, "Cast-128\n");
break;
case IPSEC_ESP_BLOWFISH:
fprintf(fd, "Blowfish\n");
break;
default:
fprintf(fd, "unknown (%d)\n", proto->id);
}
fprintf(fd, "Authentication algorithm: ");
if (!proto->data) {
fprintf(fd, "none\n");
break;
}
iproto = proto->data;
switch (iproto->auth) {
case IPSEC_AUTH_HMAC_MD5:
fprintf(fd, "HMAC-MD5\n");
break;
case IPSEC_AUTH_HMAC_SHA:
fprintf(fd, "HMAC-SHA1\n");
break;
case IPSEC_AUTH_HMAC_RIPEMD:
fprintf(fd, "HMAC-RIPEMD-160\n");
break;
case IPSEC_AUTH_HMAC_SHA2_256:
fprintf(fd, "HMAC-SHA2-256\n");
break;
case IPSEC_AUTH_HMAC_SHA2_384:
fprintf(fd, "HMAC-SHA2-384\n");
break;
case IPSEC_AUTH_HMAC_SHA2_512:
fprintf(fd, "HMAC-SHA2-512\n");
break;
case IPSEC_AUTH_DES_MAC:
case IPSEC_AUTH_KPDK:
/* XXX We should be supporting KPDK */
fprintf(fd, "unknown (%d)", iproto->auth);
break;
default:
fprintf(fd, "none\n");
}
break;
case IPSEC_PROTO_IPSEC_AH:
hashlen = ipsec_ah_keylength(proto);
fprintf(fd, "Transform: IPsec AH\n");
fprintf(fd, "Encryption not used.\n");
fprintf(fd, "Authentication key length: %d\n", hashlen);
fprintf(fd, "Authentication algorithm: ");
switch (proto->id) {
case IPSEC_AH_MD5:
fprintf(fd, "HMAC-MD5\n");
break;
case IPSEC_AH_SHA:
fprintf(fd, "HMAC-SHA1\n");
break;
case IPSEC_AH_RIPEMD:
fprintf(fd, "HMAC-RIPEMD-160\n");
break;
case IPSEC_AH_SHA2_256:
fprintf(fd, "HMAC-SHA2-256\n");
break;
case IPSEC_AH_SHA2_384:
fprintf(fd, "HMAC-SHA2-384\n");
break;
case IPSEC_AH_SHA2_512:
fprintf(fd, "HMAC-SHA2-512\n");
break;
default:
fprintf(fd, "unknown (%d)", proto->id);
}
break;
default:
fprintf(fd, "report_proto: invalid proto %d\n", proto->proto);
}
}
/*
* Display SA lifetimes.
*/
static void
report_lifetimes(FILE *fd, struct sa *sa)
{
long timeout;
if (sa->seconds)
fprintf(fd, "Lifetime: %llu seconds\n", sa->seconds);
if (sa->soft_death) {
timeout = get_timeout(&sa->soft_death->expiration);
if (timeout < 0)
fprintf(fd, "<no soft timeout>\n");
else
fprintf(fd, "Soft timeout in %ld seconds\n", timeout);
}
if (sa->death) {
timeout = get_timeout(&sa->death->expiration);
if (timeout < 0)
fprintf(fd, "No hard timeout>\n");
else
fprintf(fd, "Hard timeout in %ld seconds\n", timeout);
}
if (sa->kilobytes)
fprintf(fd, "Lifetime: %llu kilobytes\n", sa->kilobytes);
}
/*
* Print phase 1 specific information.
*/
static void
report_phase1(FILE *fd, struct sa *sa)
{
/* Cookies. */
fprintf(fd, "icookie %08x%08x rcookie %08x%08x\n",
decode_32(sa->cookies), decode_32(sa->cookies + 4),
decode_32(sa->cookies + 8), decode_32(sa->cookies + 12));
}
/*
* Print phase 2 specific information.
*/
static void
report_phase2(FILE *fd, struct sa *sa)
{
struct proto *proto;
int i;
/* Transform information. */
for (proto = TAILQ_FIRST(&sa->protos); proto;
proto = TAILQ_NEXT(proto, link)) {
/* SPI values. */
for (i = 0; i < 2; i++)
if (proto->spi[i])
report_spi(fd, proto->spi[i],
proto->spi_sz[i], i);
else
fprintf(fd, "SPI %d not defined.\n", i);
/* Proto values. */
report_proto(fd, proto);
}
}
/* Report all the SAs to the report channel. */
void
sa_report(void)
{
struct sa *sa;
int i;
for (i = 0; i <= bucket_mask; i++)
for (sa = LIST_FIRST(&sa_tab[i]); sa; sa = LIST_NEXT(sa, link))
sa_dump(LOG_REPORT, 0, "sa_report", sa);
}
/*
* Print an SA's connection details to file SA_FILE.
*/
static void
sa_dump_all(FILE *fd, struct sa *sa)
{
/* SA name and phase. */
fprintf(fd, "SA name: %s", sa->name ? sa->name : "<unnamed>");
fprintf(fd, " (Phase %d%s)\n", sa->phase, sa->phase == 1 ?
(sa->initiator ? "/Initiator" : "/Responder") : "");
/* Source and destination IPs. */
fprintf(fd, "%s", sa->transport == NULL ? "<no transport>" :
sa->transport->vtbl->decode_ids(sa->transport));
fprintf(fd, "\n");
/* Lifetimes */
report_lifetimes(fd, sa);
fprintf(fd, "Flags 0x%08x\n", sa->flags);
if (sa->phase == 1)
report_phase1(fd, sa);
else if (sa->phase == 2)
report_phase2(fd, sa);
else {
/* Should not happen, but... */
fprintf(fd, "<unknown phase>\n");
}
/* SA separator. */
fprintf(fd, "\n");
}
/* Report info of all SAs to file 'fd'. */
void
sa_report_all(FILE *fd)
{
struct sa *sa;
int i;
for (i = 0; i <= bucket_mask; i++)
for (sa = LIST_FIRST(&sa_tab[i]); sa; sa = LIST_NEXT(sa, link))
sa_dump_all(fd, sa);
}
/* Free the protocol structure pointed to by PROTO. */
void
proto_free(struct proto *proto)
{
struct proto_attr *pa;
struct sa *sa = proto->sa;
int i;
for (i = 0; i < 2; i++)
if (proto->spi[i]) {
if (sa->doi->delete_spi)
sa->doi->delete_spi(sa, proto, i);
free(proto->spi[i]);
}
TAILQ_REMOVE(&sa->protos, proto, link);
if (proto->data) {
if (sa->doi && sa->doi->free_proto_data)
sa->doi->free_proto_data(proto->data);
free(proto->data);
}
if (proto->xf_cnt)
while ((pa = TAILQ_FIRST(&proto->xfs)) != NULL) {
free(pa->attrs);
TAILQ_REMOVE(&proto->xfs, pa, next);
free(pa);
}
LOG_DBG((LOG_SA, 90, "proto_free: freeing %p", proto));
free(proto);
}
/* Release all resources this SA is using. */
void
sa_free(struct sa *sa)
{
if (sa->death) {
timer_remove_event(sa->death);
sa->death = 0;
sa->refcnt--;
}
if (sa->soft_death) {
timer_remove_event(sa->soft_death);
sa->soft_death = 0;
sa->refcnt--;
}
if (sa->dpd_event) {
timer_remove_event(sa->dpd_event);
sa->dpd_event = 0;
}
sa_remove(sa);
}
/* Remove the SA from the hash table of live SAs. */
void
sa_remove(struct sa *sa)
{
LIST_REMOVE(sa, link);
LOG_DBG((LOG_SA, 70, "sa_remove: SA %p removed from SA list", sa));
sa_release(sa);
}
/* Raise the reference count of SA. */
void
sa_reference(struct sa *sa)
{
sa->refcnt++;
LOG_DBG((LOG_SA, 80, "sa_reference: SA %p now has %d references",
sa, sa->refcnt));
}
/* Release a reference to SA. */
void
sa_release(struct sa *sa)
{
struct cert_handler *handler;
struct proto *proto;
LOG_DBG((LOG_SA, 80, "sa_release: SA %p had %d references",
sa, sa->refcnt));
if (--sa->refcnt)
return;
LOG_DBG((LOG_SA, 60, "sa_release: freeing SA %p", sa));
while ((proto = TAILQ_FIRST(&sa->protos)) != 0)
proto_free(proto);
if (sa->data) {
if (sa->doi && sa->doi->free_sa_data)
sa->doi->free_sa_data(sa->data);
free(sa->data);
}
free(sa->id_i);
free(sa->id_r);
if (sa->recv_cert) {
handler = cert_get(sa->recv_certtype);
if (handler)
handler->cert_free(sa->recv_cert);
}
if (sa->sent_cert) {
handler = cert_get(sa->sent_certtype);
if (handler)
handler->cert_free(sa->sent_cert);
}
if (sa->recv_key)
key_free(sa->recv_keytype, ISAKMP_KEYTYPE_PUBLIC,
sa->recv_key);
free(sa->keynote_key); /* This is just a string */
if (sa->policy_id != -1)
kn_close(sa->policy_id);
free(sa->name);
free(sa->keystate);
if (sa->nat_t_keepalive)
timer_remove_event(sa->nat_t_keepalive);
if (sa->dpd_event)
timer_remove_event(sa->dpd_event);
if (sa->transport)
transport_release(sa->transport);
free(sa->tag);
free(sa);
}
/*
* Rehash the ISAKMP SA this MSG is negotiating with the responder cookie
* filled in.
*/
void
sa_isakmp_upgrade(struct message *msg)
{
struct sa *sa = TAILQ_FIRST(&msg->exchange->sa_list);
sa_remove(sa);
GET_ISAKMP_HDR_RCOOKIE(msg->iov[0].iov_base,
sa->cookies + ISAKMP_HDR_ICOOKIE_LEN);
/*
* We don't install a transport in the initiator case as we don't know
* what local address will be chosen. Do it now instead.
*/
sa->transport = msg->transport;
transport_reference(sa->transport);
sa_enter(sa);
}
#define ATTRS_SIZE (IKE_ATTR_BLOCK_SIZE + 1) /* XXX Should be dynamic. */
struct attr_validation_state {
u_int8_t *attrp[ATTRS_SIZE];
u_int8_t checked[ATTRS_SIZE];
u_int16_t len[ATTRS_SIZE];
int phase; /* IKE (1) or IPSEC (2) attrs? */
int mode; /* 0 = 'load', 1 = check */
};
/* Validate an attribute. Return 0 on match. */
static int
sa_validate_xf_attrs(u_int16_t type, u_int8_t *value, u_int16_t len,
void *arg)
{
int val0, val1;
struct attr_validation_state *avs =
(struct attr_validation_state *)arg;
LOG_DBG((LOG_SA, 95, "sa_validate_xf_attrs: phase %d mode %d type %d "
"len %d", avs->phase, avs->mode, type, len));
/* Make sure the phase and type are valid. */
if (avs->phase == 1) {
if (type < IKE_ATTR_ENCRYPTION_ALGORITHM ||
type > IKE_ATTR_BLOCK_SIZE)
return 1;
} else if (avs->phase == 2) {
if (type < IPSEC_ATTR_SA_LIFE_TYPE ||
type > IPSEC_ATTR_ECN_TUNNEL)
return 1;
} else
return 1;
if (avs->mode == 0) { /* Load attrs. */
avs->attrp[type] = value;
avs->len[type] = len;
return 0;
}
/* Checking for a missing attribute is an immediate failure. */
if (!avs->attrp[type])
return 1;
/* Match the loaded attribute against this one, mark it as checked. */
avs->checked[type]++;
switch (len) {
case 2:
val0 = (int)decode_16(value);
break;
case 4:
val0 = (int)decode_32(value);
break;
default:
return 1;
}
switch (avs->len[type]) {
case 2:
val1 = (int)decode_16(avs->attrp[type]);
break;
case 4:
val1 = (int)decode_32(avs->attrp[type]);
break;
default:
return 1;
}
/* Return 0 when the values are equal. */
return (val0 != val1);
}
/*
* This function is used to validate the returned proposal (protection suite)
* we get from the responder against a proposal we sent. Only run as initiator.
* We return 0 if a match is found (in any transform of this proposal), 1
* otherwise. Also see note in sa_add_transform() below.
*/
static int
sa_validate_proto_xf(struct proto *match, struct payload *xf, int phase)
{
struct attr_validation_state *avs;
struct proto_attr *pa;
int found = 0;
size_t i;
u_int8_t xf_id;
if (!match->xf_cnt)
return 0;
if (match->proto != GET_ISAKMP_PROP_PROTO(xf->context->p)) {
LOG_DBG((LOG_SA, 70, "sa_validate_proto_xf: proto %p (#%d) "
"protocol mismatch", match, match->no));
return 1;
}
avs = (struct attr_validation_state *)calloc(1, sizeof *avs);
if (!avs) {
log_error("sa_validate_proto_xf: calloc (1, %lu)",
(unsigned long)sizeof *avs);
return 1;
}
avs->phase = phase;
/* Load the "proposal candidate" attribute set. */
(void)attribute_map(xf->p + ISAKMP_TRANSFORM_SA_ATTRS_OFF,
GET_ISAKMP_GEN_LENGTH(xf->p) - ISAKMP_TRANSFORM_SA_ATTRS_OFF,
sa_validate_xf_attrs, avs);
xf_id = GET_ISAKMP_TRANSFORM_ID(xf->p);
/* Check against the transforms we suggested. */
avs->mode++;
for (pa = TAILQ_FIRST(&match->xfs); pa && !found;
pa = TAILQ_NEXT(pa, next)) {
if (xf_id != GET_ISAKMP_TRANSFORM_ID(pa->attrs))
continue;
bzero(avs->checked, sizeof avs->checked);
if (attribute_map(pa->attrs + ISAKMP_TRANSFORM_SA_ATTRS_OFF,
pa->len - ISAKMP_TRANSFORM_SA_ATTRS_OFF,
sa_validate_xf_attrs, avs) == 0)
found++;
LOG_DBG((LOG_SA, 80, "sa_validate_proto_xf: attr_map "
"xf %p proto %p pa %p found %d", xf, match, pa, found));
if (!found)
continue;
/*
* Require all attributes present and checked. XXX perhaps
* not?
*/
for (i = 0; i < sizeof avs->checked; i++)
if (avs->attrp[i] && !avs->checked[i])
found = 0;
LOG_DBG((LOG_SA, 80, "sa_validate_proto_xf: req_attr "
"xf %p proto %p pa %p found %d", xf, match, pa, found));
}
free(avs);
return found ? 0 : 1;
}
/*
* Register the chosen transform XF into SA. As a side effect set PROTOP
* to point at the corresponding proto structure. INITIATOR is true if we
* are the initiator.
*/
int
sa_add_transform(struct sa *sa, struct payload *xf, int initiator,
struct proto **protop)
{
struct proto *proto;
struct payload *prop = xf->context;
*protop = 0;
if (!initiator) {
proto = calloc(1, sizeof *proto);
if (!proto)
log_error("sa_add_transform: calloc (1, %lu) failed",
(unsigned long)sizeof *proto);
} else {
/*
* RFC 2408, section 4.2 states the responder SHOULD use the
* proposal number from the initiator (i.e us), in it's
* selected proposal to make this lookup easier. Most vendors
* follow this. One noted exception is the CiscoPIX (and
* perhaps other Cisco products).
*
* We start by matching on the proposal number, as before.
*/
for (proto = TAILQ_FIRST(&sa->protos);
proto && proto->no != GET_ISAKMP_PROP_NO(prop->p);
proto = TAILQ_NEXT(proto, link))
;
/*
* If we did not find a match, search through all proposals
* and xforms.
*/
if (!proto || sa_validate_proto_xf(proto, xf, sa->phase) != 0)
for (proto = TAILQ_FIRST(&sa->protos);
proto && sa_validate_proto_xf(proto, xf, sa->phase) != 0;
proto = TAILQ_NEXT(proto, link))
;
}
if (!proto)
return -1;
*protop = proto;
/* Allocate DOI-specific part. */
if (!initiator) {
proto->data = calloc(1, sa->doi->proto_size);
if (!proto->data) {
log_error("sa_add_transform: calloc (1, %lu) failed",
(unsigned long)sa->doi->proto_size);
goto cleanup;
}
}
proto->no = GET_ISAKMP_PROP_NO(prop->p);
proto->proto = GET_ISAKMP_PROP_PROTO(prop->p);
proto->spi_sz[0] = GET_ISAKMP_PROP_SPI_SZ(prop->p);
if (proto->spi_sz[0]) {
proto->spi[0] = malloc(proto->spi_sz[0]);
if (!proto->spi[0])
goto cleanup;
memcpy(proto->spi[0], prop->p + ISAKMP_PROP_SPI_OFF,
proto->spi_sz[0]);
}
proto->chosen = xf;
proto->sa = sa;
proto->id = GET_ISAKMP_TRANSFORM_ID(xf->p);
if (!initiator)
TAILQ_INSERT_TAIL(&sa->protos, proto, link);
/* Let the DOI get at proto for initializing its own data. */
if (sa->doi->proto_init)
sa->doi->proto_init(proto, 0);
LOG_DBG((LOG_SA, 80,
"sa_add_transform: "
"proto %p no %d proto %d chosen %p sa %p id %d",
proto, proto->no, proto->proto, proto->chosen, proto->sa,
proto->id));
return 0;
cleanup:
if (!initiator) {
free(proto->data);
free(proto);
}
*protop = 0;
return -1;
}
/* Delete an SA. Tell the peer if NOTIFY is set. */
void
sa_delete(struct sa *sa, int notify)
{
if (notify)
message_send_delete(sa);
sa_free(sa);
}
/* Teardown all SAs. */
void
sa_teardown_all(void)
{
int i;
struct sa *sa, *next = 0;
LOG_DBG((LOG_SA, 70, "sa_teardown_all:"));
/* Get Phase 2 SAs. */
for (i = 0; i <= bucket_mask; i++)
for (sa = LIST_FIRST(&sa_tab[i]); sa; sa = next) {
next = LIST_NEXT(sa, link);
if (sa->phase == 2) {
/*
* Teardown the phase 2 SAs by name, similar
* to ui_teardown.
*/
LOG_DBG((LOG_SA, 70,
"sa_teardown_all: tearing down SA %s",
sa->name ? sa->name : "<unnamed>"));
if (sa->name)
connection_teardown(sa->name);
sa_delete(sa, 1);
}
}
}
/*
* This function will get called when we are closing in on the death time of SA
*/
static void
sa_soft_expire(void *v_sa)
{
struct sa *sa = v_sa;
sa->soft_death = 0;
sa_release(sa);
if ((sa->flags & (SA_FLAG_STAYALIVE | SA_FLAG_REPLACED)) ==
SA_FLAG_STAYALIVE)
exchange_establish(sa->name, 0, 0, 1);
else
/*
* Start to watch the use of this SA, so a renegotiation can
* happen as soon as it is shown to be alive.
*/
sa->flags |= SA_FLAG_FADING;
}
/* SA has passed its best before date. */
static void
sa_hard_expire(void *v_sa)
{
struct sa *sa = v_sa;
sa->death = 0;
sa_release(sa);
if ((sa->flags & (SA_FLAG_STAYALIVE | SA_FLAG_REPLACED)) ==
SA_FLAG_STAYALIVE)
exchange_establish(sa->name, 0, 0, 1);
sa_delete(sa, 1);
}
void
sa_reinit(void)
{
struct sa *sa;
char *tag;
int i;
/* For now; only do this if we have the proper tag configured. */
tag = conf_get_str("General", "Renegotiate-on-HUP");
if (!tag)
return;
LOG_DBG((LOG_SA, 30, "sa_reinit: renegotiating active connections"));
/*
* Get phase 2 SAs. Soft expire those without active exchanges. Do
* not touch a phase 2 SA where the soft expiration is not set, ie.
* the SA is not yet established.
*/
for (i = 0; i <= bucket_mask; i++)
for (sa = LIST_FIRST(&sa_tab[i]); sa; sa = LIST_NEXT(sa, link))
if (sa->phase == 2)
if (exchange_lookup_by_name(sa->name,
sa->phase) == 0 && sa->soft_death) {
timer_remove_event(sa->soft_death);
sa_soft_expire(sa);
}
}
/*
* Get an SA attribute's flag value out of textual description.
*/
int
sa_flag(char *attr)
{
static struct sa_flag_map {
char *name;
int flag;
} sa_flag_map[] = {
{
"active-only", SA_FLAG_ACTIVE_ONLY
},
/*
* Below this point are flags that are internal to the
* implementation.
*/
{
"__ondemand", SA_FLAG_ONDEMAND
},
{
"ikecfg", SA_FLAG_IKECFG
},
};
size_t i;
for (i = 0; i < sizeof sa_flag_map / sizeof sa_flag_map[0]; i++)
if (strcasecmp(attr, sa_flag_map[i].name) == 0)
return sa_flag_map[i].flag;
log_print("sa_flag: attribute \"%s\" unknown", attr);
return 0;
}
/* Mark SA as replaced. */
void
sa_mark_replaced(struct sa *sa)
{
LOG_DBG((LOG_SA, 60, "sa_mark_replaced: SA %p (%s) marked as replaced",
sa, sa->name ? sa->name : "unnamed"));
if (sa->dpd_event) {
timer_remove_event(sa->dpd_event);
sa->dpd_event = 0;
}
sa->flags |= SA_FLAG_REPLACED;
}
/*
* Setup expiration timers for SA. This is used for ISAKMP SAs, but also
* possible to use for application SAs if the application does not deal
* with expirations itself. An example is the Linux FreeS/WAN KLIPS IPsec
* stack.
*/
int
sa_setup_expirations(struct sa *sa)
{
struct timeval expiration;
u_int64_t seconds = sa->seconds;
/*
* Set the soft timeout to a random percentage between 85 & 95 of
* the negotiated lifetime to break strictly synchronized
* renegotiations. This works better when the randomization is on the
* order of processing plus network-roundtrip times, or larger.
* I.e. it depends on configuration and negotiated lifetimes.
* It is not good to do the decrease on the hard timeout, because then
* we may drop our SA before our peer.
* XXX Better scheme to come?
*/
if (!sa->soft_death) {
gettimeofday(&expiration, 0);
/*
* XXX This should probably be configuration controlled
* somehow.
*/
seconds = sa->seconds * (850 + rand_32() % 100) / 1000;
LOG_DBG((LOG_TIMER, 95,
"sa_setup_expirations: SA %p soft timeout in %llu seconds",
sa, seconds));
expiration.tv_sec += seconds;
sa->soft_death = timer_add_event("sa_soft_expire",
sa_soft_expire, sa, &expiration);
if (!sa->soft_death) {
/* If we don't give up we might start leaking... */
sa_delete(sa, 1);
return -1;
}
sa_reference(sa);
}
if (!sa->death) {
gettimeofday(&expiration, 0);
LOG_DBG((LOG_TIMER, 95,
"sa_setup_expirations: SA %p hard timeout in %llu seconds",
sa, sa->seconds));
expiration.tv_sec += sa->seconds;
sa->death = timer_add_event("sa_hard_expire", sa_hard_expire,
sa, &expiration);
if (!sa->death) {
/* If we don't give up we might start leaking... */
sa_delete(sa, 1);
return -1;
}
sa_reference(sa);
}
return 0;
}