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vpnc.c
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vpnc.c
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/* IPSec VPN client compatible with Cisco equipment.
Copyright (C) 2002 Geoffrey Keating
Copyright (C) 2003-2005 Maurice Massar
Copyright (C) 2004 Tomas Mraz
Copyright (C) 2004 Martin von Gagern
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
$Id$
*/
#define _GNU_SOURCE
#include <assert.h>
#include <unistd.h>
#include <sys/fcntl.h>
#include <stdio.h>
#include <errno.h>
#include <string.h>
#include <time.h>
#include <stdlib.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <netdb.h>
#include <arpa/inet.h>
#include <poll.h>
#include <sys/ioctl.h>
#include <sys/utsname.h>
#include <sys/wait.h>
#include <sys/mman.h>
#include <gcrypt.h>
#include "crypto.h"
#include "sysdep.h"
#include "config.h"
#include "isakmp-pkt.h"
#include "math_group.h"
#include "dh.h"
#include "vpnc.h"
#include "tunip.h"
#include "supp.h"
#if defined(__CYGWIN__)
GCRY_THREAD_OPTION_PTHREAD_IMPL;
#endif
#define ISAKMP_PORT (500)
#define ISAKMP_PORT_NATT (4500)
const unsigned char VID_XAUTH[] = { /* "draft-ietf-ipsra-isakmp-xauth-06.txt"/8 */
0x09, 0x00, 0x26, 0x89, 0xDF, 0xD6, 0xB7, 0x12
};
const unsigned char VID_DPD[] = { /* Dead Peer Detection, RFC 3706 */
0xAF, 0xCA, 0xD7, 0x13, 0x68, 0xA1, 0xF1, 0xC9,
0x6B, 0x86, 0x96, 0xFC, 0x77, 0x57, 0x01, 0x00
};
const unsigned char VID_UNITY[] = { /* "CISCO-UNITY"/14 + major + minor */
0x12, 0xF5, 0xF2, 0x8C, 0x45, 0x71, 0x68, 0xA9,
0x70, 0x2D, 0x9F, 0xE2, 0x74, 0xCC, 0x01, 0x00
};
const unsigned char VID_UNKNOWN[] = {
0x12, 0x6E, 0x1F, 0x57, 0x72, 0x91, 0x15, 0x3B,
0x20, 0x48, 0x5F, 0x7F, 0x15, 0x5B, 0x4B, 0xC8
};
const unsigned char VID_NATT_00[] = { /* "draft-ietf-ipsec-nat-t-ike-00" */
0x44, 0x85, 0x15, 0x2d, 0x18, 0xb6, 0xbb, 0xcd,
0x0b, 0xe8, 0xa8, 0x46, 0x95, 0x79, 0xdd, 0xcc
};
const unsigned char VID_NATT_01[] = { /* "draft-ietf-ipsec-nat-t-ike-01" */
0x16, 0xf6, 0xca, 0x16, 0xe4, 0xa4, 0x06, 0x6d,
0x83, 0x82, 0x1a, 0x0f, 0x0a, 0xea, 0xa8, 0x62
};
const unsigned char VID_NATT_02[] = { /* "draft-ietf-ipsec-nat-t-ike-02" */
0xcd, 0x60, 0x46, 0x43, 0x35, 0xdf, 0x21, 0xf8,
0x7c, 0xfd, 0xb2, 0xfc, 0x68, 0xb6, 0xa4, 0x48
};
const unsigned char VID_NATT_02N[] = { /* "draft-ietf-ipsec-nat-t-ike-02\n" */
0x90, 0xCB, 0x80, 0x91, 0x3E, 0xBB, 0x69, 0x6E,
0x08, 0x63, 0x81, 0xB5, 0xEC, 0x42, 0x7B, 0x1F
};
const unsigned char VID_NATT_03[] = { /* "draft-ietf-ipsec-nat-t-ike-03" */
0x7d, 0x94, 0x19, 0xa6, 0x53, 0x10, 0xca, 0x6f,
0x2c, 0x17, 0x9d, 0x92, 0x15, 0x52, 0x9d, 0x56
};
const unsigned char VID_NATT_RFC[] = { /* "RFC 3947" */
0x4A, 0x13, 0x1C, 0x81, 0x07, 0x03, 0x58, 0x45,
0x5C, 0x57, 0x28, 0xF2, 0x0E, 0x95, 0x45, 0x2F
};
const unsigned char VID_DWR[] = { /* DWR: Delete with reason */
0x2D, 0x79, 0x22, 0xC6, 0xB3, 0x01, 0xD9, 0xB0,
0xE1, 0x34, 0x27, 0x39, 0xE9, 0xCF, 0xBB, 0xD5
};
/* Cisco Unknown1:
*const unsigned char VID_CISCO_UNKNOWN_1[] = {
* 1f07f70eaa6514d3b0fa96542a500407
*};
*/
const unsigned char VID_CISCO_FRAG[] = { /* "FRAGMENTATION" */
0x40, 0x48, 0xB7, 0xD5, 0x6E, 0xBC, 0xE8, 0x85,
0x25, 0xE7, 0xDE, 0x7F, 0x00, 0xD6, 0xC2, 0xD3,
0x80, 0x00, 0x00, 0x00
};
const unsigned char VID_CISCO_FRAG_02[] = { /* "FRAGMENTATION" */
0x40, 0x48, 0xB7, 0xD5, 0x6E, 0xBC, 0xE8, 0x85,
0x25, 0xE7, 0xDE, 0x7F, 0x00, 0xD6, 0xC2, 0xD3,
0xC0, 0x00, 0x00, 0x00
};
const unsigned char VID_NETSCREEN_15[] = { /* netscreen 15 */
0x16, 0x6f, 0x93, 0x2d, 0x55, 0xeb, 0x64, 0xd8,
0xe4, 0xdf, 0x4f, 0xd3, 0x7e, 0x23, 0x13, 0xf0,
0xd0, 0xfd, 0x84, 0x51, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00
};
const unsigned char VID_CISCO_CONCENTRATOR[] = {
0x1f, 0x07, 0xf7, 0x0e, 0xaa, 0x65, 0x14, 0xd3,
0xb0, 0xfa, 0x96, 0x54, 0x2a, 0x50, 0x01, 0x00
};
const unsigned char VID_HEARTBEAT_NOTIFY[] = { /* Heartbeat Notify */
0x48, 0x65, 0x61, 0x72, 0x74, 0x42, 0x65, 0x61,
0x74, 0x5f, 0x4e, 0x6f, 0x74, 0x69, 0x66, 0x79,
0x38, 0x6b, 0x01, 0x00
};
const unsigned char VID_NORTEL_CONT[] = { /* BNES: Bay Networks Enterprise Switch + version/id of some kind */
0x42, 0x4e, 0x45, 0x53, 0x00, 0x00, 0x00, 0x0a
};
const unsigned char FW_UNKNOWN_TYPEINFO[] = {
0x80, 0x01, 0x00, 0x01, 0x80, 0x02, 0x00, 0x01,
0x80, 0x03, 0x00, 0x02
};
struct vid_element {
const unsigned char* valueptr;
const uint16_t length;
const char* descr;
};
const struct vid_element vid_list[] = {
{ VID_XAUTH, sizeof(VID_XAUTH), "Xauth" },
{ VID_DPD, sizeof(VID_DPD), "DPD" },
{ VID_UNITY, sizeof(VID_UNITY), "Cisco Unity" },
{ VID_NATT_00, sizeof(VID_NATT_00), "Nat-T 00" },
{ VID_NATT_01, sizeof(VID_NATT_01), "Nat-T 01" },
{ VID_NATT_02, sizeof(VID_NATT_02), "Nat-T 02" },
{ VID_NATT_02N, sizeof(VID_NATT_02N), "Nat-T 02N" },
{ VID_NATT_03, sizeof(VID_NATT_03), "Nat-T 03" },
{ VID_NATT_RFC, sizeof(VID_NATT_RFC), "Nat-T RFC" },
{ VID_DWR, sizeof(VID_DWR), "Delete With Reason" },
{ VID_CISCO_FRAG, sizeof(VID_CISCO_FRAG), "Cisco Fragmentation" },
{ VID_CISCO_FRAG_02, sizeof(VID_CISCO_FRAG_02), "Cisco Fragmentation" },
{ VID_CISCO_CONCENTRATOR, sizeof(VID_CISCO_CONCENTRATOR), "Cisco Concentrator" },
{ VID_NETSCREEN_15, sizeof(VID_NETSCREEN_15), "Netscreen 15" },
{ VID_NORTEL_CONT, sizeof(VID_NORTEL_CONT), "Nortel Contivity" },
{ VID_HEARTBEAT_NOTIFY, sizeof(VID_HEARTBEAT_NOTIFY), "Heartbeat Notify" },
{ NULL, 0, NULL }
};
/* What are DWR-Code and DWR-Text ? */
static uint8_t r_packet[8192];
static ssize_t r_length;
static struct sa_block *s_atexit_sa;
static void close_tunnel(struct sa_block *s);
void print_vid(const unsigned char *vid, uint16_t len) {
int vid_index = 0;
if (opt_debug < 2)
return;
while (vid_list[vid_index].length) {
if (len == vid_list[vid_index].length &&
crypto_memcmp(vid_list[vid_index].valueptr, vid, len) == 0) {
printf(" (%s)\n", vid_list[vid_index].descr);
return;
}
vid_index++;
}
printf(" (unknown)\n");
}
static __inline__ int min(int a, int b)
{
return (a < b) ? a : b;
}
static void addenv(const void *name, const char *value)
{
char *strbuf = NULL, *oldval;
oldval = getenv(name);
if (oldval != NULL) {
strbuf = xallocc(strlen(oldval) + 1 + strlen(value) + 1);
strcat(strbuf, oldval);
strcat(strbuf, " ");
strcat(strbuf, value);
}
setenv(name, strbuf ? strbuf : value, 1);
free(strbuf);
}
static void addenv_ipv4(const void *name, uint8_t * data)
{
addenv(name, inet_ntoa(*((struct in_addr *)data)));
}
static int make_socket(struct sa_block *s, uint16_t src_port, uint16_t dst_port)
{
int sock;
struct sockaddr_in name;
socklen_t len = sizeof(name);
/* create the socket */
sock = socket(PF_INET, SOCK_DGRAM, 0);
if (sock < 0)
error(1, errno, "making socket");
#ifdef FD_CLOEXEC
/* do not pass socket to vpnc-script, etc. */
fcntl(sock, F_SETFD, FD_CLOEXEC);
#endif
/* give the socket a name */
name.sin_family = AF_INET;
name.sin_addr = s->opt_src_ip;
name.sin_port = htons(src_port);
if (bind(sock, (struct sockaddr *)&name, sizeof(name)) < 0)
error(1, errno, "Error binding to source port. Try '--local-port 0'\nFailed to bind to %s:%d", inet_ntoa(s->opt_src_ip), src_port);
/* connect the socket */
name.sin_family = AF_INET;
name.sin_addr = s->dst;
name.sin_port = htons(dst_port);
if (connect(sock, (struct sockaddr *)&name, sizeof(name)) < 0)
error(1, errno, "connecting to port %d", ntohs(dst_port));
/* who am I */
if (getsockname(sock, (struct sockaddr *)&name, &len) < 0)
error(1, errno, "reading local address from socket %d", sock);
s->src = name.sin_addr;
return sock;
}
static void cleanup(struct sa_block *s) {
if (s->ike_fd != 0) {
close(s->ike_fd);
s->ike_fd = 0;
}
if (s->esp_fd != 0) {
close(s->esp_fd);
s->esp_fd = 0;
}
if (s->ike.resend_hash) {
free(s->ike.resend_hash);
s->ike.resend_hash = NULL;
}
if (s->ike.skeyid_d) {
free(s->ike.skeyid_d);
s->ike.skeyid_d = NULL;
}
if (s->ike.skeyid_a) {
free(s->ike.skeyid_a);
s->ike.skeyid_a = NULL;
}
if (s->ike.initial_iv) {
free(s->ike.initial_iv);
s->ike.initial_iv = NULL;
}
if (s->ike.current_iv) {
free(s->ike.current_iv);
s->ike.current_iv = NULL;
}
if (s->ike.key) {
crypto_memzero(s->ike.key, s->ike.keylen);
free(s->ike.key);
s->ike.key = NULL;
}
if (s->ipsec.rx.key) {
crypto_memzero(s->ipsec.rx.key, s->ipsec.key_len + s->ipsec.md_len);
free(s->ipsec.rx.key);
s->ipsec.rx.key = NULL;
}
if (s->ipsec.tx.key) {
crypto_memzero(s->ipsec.tx.key, s->ipsec.key_len + s->ipsec.md_len);
free(s->ipsec.tx.key);
s->ipsec.tx.key = NULL;
}
if (s->ipsec.rx.cry_ctx) {
gcry_cipher_close(s->ipsec.rx.cry_ctx);
s->ipsec.rx.cry_ctx = NULL;
}
if (s->ipsec.tx.cry_ctx) {
gcry_cipher_close(s->ipsec.tx.cry_ctx);
s->ipsec.tx.cry_ctx = NULL;
}
}
static void init_sockaddr(struct in_addr *dst, const char *hostname)
{
struct hostent *hostinfo;
if (inet_aton(hostname, dst) == 0) {
hostinfo = gethostbyname(hostname);
if (hostinfo == NULL)
error(1, 0, "unknown host `%s'\n", hostname);
*dst = *(struct in_addr *)hostinfo->h_addr;
}
}
static void init_netaddr(struct in_addr *net, const char *string)
{
char *p;
if ((p = strchr(string, '/')) != NULL) {
char *host = xallocc(p - string + 1);
memcpy(host, string, p - string + 1);
host[p - string] = '\0';
init_sockaddr((struct in_addr *)net, host);
free(host);
if (strchr(p + 1, '.') != NULL)
init_sockaddr(net + 1, p + 1);
else {
int bits = atoi(p + 1);
unsigned long mask = (1 << bits) - 1;
memcpy((char *)(net + 1), (char *)&mask, 4);
}
} else {
crypto_memzero((char *)net, 8);
}
}
static void setup_tunnel(struct sa_block *s)
{
int ret;
setenv("reason", "pre-init", 1);
ret = system(config[CONFIG_SCRIPT]);
if(WEXITSTATUS(ret) != 0) {
error(1, errno, "can't execute config script");
}
if (config[CONFIG_IF_NAME])
memcpy(s->tun_name, config[CONFIG_IF_NAME], strlen(config[CONFIG_IF_NAME]));
s->tun_fd = tun_open(s->tun_name, opt_if_mode);
DEBUG(2, printf("using interface %s\n", s->tun_name));
setenv("TUNDEV", s->tun_name, 1);
if (s->tun_fd == -1)
error(1, errno, "can't initialise tunnel interface");
#ifdef FD_CLOEXEC
/* do not pass socket to vpnc-script, etc. */
fcntl(s->tun_fd, F_SETFD, FD_CLOEXEC);
#endif
if (opt_if_mode == IF_MODE_TAP) {
if (tun_get_hwaddr(s->tun_fd, s->tun_name, s->tun_hwaddr) < 0) {
error(1, errno, "can't get tunnel HW address");
}
hex_dump("interface HW addr", s->tun_hwaddr, ETH_ALEN, NULL);
}
unsetenv("INTERNAL_IP4_MTU");
if (config[CONFIG_IF_MTU]) {
int mtu;
mtu = atoi(config[CONFIG_IF_MTU]);
if (mtu < 0 || mtu > 65535) {
DEBUG(1, printf("ignore MTU option. Use automatic detection\n"));
mtu = 0;
}
if (mtu > 0) {
char *strbuf;
ret = asprintf(&strbuf, "%d", mtu);
if (ret == 1) {
error(1, errno, "can't build mtu string");
}
setenv("INTERNAL_IP4_MTU", strbuf, 1);
free(strbuf);
}
}
}
static void atexit_close(void)
{
if (s_atexit_sa != NULL) {
close_tunnel(s_atexit_sa);
s_atexit_sa = NULL;
}
}
static void config_tunnel(struct sa_block *s)
{
int ret;
setenv("VPNGATEWAY", inet_ntoa(s->dst), 1);
setenv("reason", "connect", 1);
ret = system(config[CONFIG_SCRIPT]);
if(WEXITSTATUS(ret) != 0) {
error(1, errno, "can't execute config script");
}
s_atexit_sa = s;
atexit(atexit_close);
}
static void close_tunnel(struct sa_block *s)
{
int ret;
setenv("reason", "disconnect", 1);
ret = system(config[CONFIG_SCRIPT]);
if(WEXITSTATUS(ret) != 0) {
error(1, errno, "can't execute config script");
}
tun_close(s->tun_fd, s->tun_name);
}
static int recv_ignore_dup(struct sa_block *s, void *recvbuf, size_t recvbufsize)
{
uint8_t *resend_check_hash;
int recvsize, hash_len;
recvsize = recv(s->ike_fd, recvbuf, recvbufsize, 0);
if (recvsize < 0)
error(1, errno, "receiving packet");
if ((unsigned int)recvsize > recvbufsize)
error(1, errno, "received packet too large for buffer");
/* skip (not only) NAT-T draft-0 keepalives */
if ( /* (s->ipsec.natt_active_mode == NATT_ACTIVE_DRAFT_OLD) && */
(recvsize == 1) && (*((u_char *)(recvbuf)) == 0xff))
{
if ((s->ipsec.natt_active_mode != NATT_ACTIVE_DRAFT_OLD))
{
DEBUG(2, printf("Received UDP NAT-Keepalive bug nat active mode incorrect: %d\n", s->ipsec.natt_active_mode));
}
return -1;
}
hash_len = gcry_md_get_algo_dlen(GCRY_MD_SHA1);
resend_check_hash = malloc(hash_len);
gcry_md_hash_buffer(GCRY_MD_SHA1, resend_check_hash, recvbuf, recvsize);
if (s->ike.resend_hash && crypto_memcmp(s->ike.resend_hash, resend_check_hash, hash_len) == 0) {
free(resend_check_hash);
/* FIXME: if we get a retransmission, we probably should do a retransmission too */
DEBUG(2, printf("Received duplicated packet, dropping it!\n"));
return -1;
}
if (!s->ike.resend_hash) {
s->ike.resend_hash = resend_check_hash;
} else {
memcpy(s->ike.resend_hash, resend_check_hash, hash_len);
free(resend_check_hash);
}
return recvsize;
}
/* Send TOSEND of size SENDSIZE to the socket. Then wait for a new packet,
resending TOSEND on timeout, and ignoring duplicate packets; the
new packet is put in RECVBUF of size RECVBUFSIZE and the actual size
of the new packet is returned. */
static ssize_t sendrecv(struct sa_block *s, void *recvbuf, size_t recvbufsize, void *tosend, size_t sendsize, int sendonly)
{
struct pollfd pfd;
int tries = 0;
int recvsize = -1;
time_t start = time(NULL);
time_t end = 0;
void *realtosend;
pfd.fd = s->ike_fd;
pfd.events = POLLIN;
tries = 0;
if ((s->ipsec.natt_active_mode == NATT_ACTIVE_RFC) && (tosend != NULL)) {
DEBUG(2, printf("NAT-T mode, adding non-esp marker\n"));
realtosend = xallocc(sendsize+4);
memmove((char*)realtosend+4, tosend, sendsize);
sendsize += 4;
} else {
realtosend = tosend;
}
for (;;) {
int pollresult;
if (realtosend != NULL)
if (write(s->ike_fd, realtosend, sendsize) != (int)sendsize)
error(1, errno, "can't send packet");
if (sendonly)
break;
do {
pollresult = poll(&pfd, 1, s->ike.timeout << tries);
} while (pollresult == -1 && errno == EINTR);
if (pollresult == -1)
error(1, errno, "can't poll socket");
if (pollresult != 0) {
recvsize = recv_ignore_dup(s, recvbuf, recvbufsize);
end = time(NULL);
if (recvsize != -1)
break;
continue;
}
if (tries > 2)
error(1, 0, "no response from target");
tries++;
}
if (realtosend != tosend)
free(realtosend);
if (sendonly)
return 0;
if ((s->ipsec.natt_active_mode == NATT_ACTIVE_RFC)&&(recvsize > 4)) {
recvsize -= 4; /* 4 bytes non-esp marker */
memmove(recvbuf, (char *)recvbuf+4, recvsize);
}
DEBUGTOP(3, printf("\n receiving: <========================\n"));
/* Wait at least 2s for a response or 4 times the time it took
* last time. */
if (start >= end)
s->ike.timeout = 2000;
else
s->ike.timeout = 4000 * (end - start);
return recvsize;
}
static int isakmp_crypt(struct sa_block *s, uint8_t * block, size_t blocklen, int enc)
{
unsigned char *new_iv, *iv = NULL;
int info_ex;
gcry_cipher_hd_t cry_ctx;
if (blocklen < ISAKMP_PAYLOAD_O || ((blocklen - ISAKMP_PAYLOAD_O) % s->ike.ivlen != 0))
abort();
if (!enc && (crypto_memcmp(block + ISAKMP_I_COOKIE_O, s->ike.i_cookie, ISAKMP_COOKIE_LENGTH) != 0
|| crypto_memcmp(block + ISAKMP_R_COOKIE_O, s->ike.r_cookie, ISAKMP_COOKIE_LENGTH) != 0)) {
DEBUG(2, printf("got packet with wrong cookies\n"));
return ISAKMP_N_INVALID_COOKIE;
}
info_ex = block[ISAKMP_EXCHANGE_TYPE_O] == ISAKMP_EXCHANGE_INFORMATIONAL;
if (crypto_memcmp(block + ISAKMP_MESSAGE_ID_O, s->ike.current_iv_msgid, 4) != 0) {
gcry_md_hd_t md_ctx;
gcry_md_open(&md_ctx, s->ike.md_algo, 0);
gcry_md_write(md_ctx, s->ike.initial_iv, s->ike.ivlen);
gcry_md_write(md_ctx, block + ISAKMP_MESSAGE_ID_O, 4);
gcry_md_final(md_ctx);
if (info_ex) {
iv = xallocc(s->ike.ivlen);
memcpy(iv, gcry_md_read(md_ctx, 0), s->ike.ivlen);
} else {
memcpy(s->ike.current_iv, gcry_md_read(md_ctx, 0), s->ike.ivlen);
memcpy(s->ike.current_iv_msgid, block + ISAKMP_MESSAGE_ID_O, 4);
}
gcry_md_close(md_ctx);
} else if (info_ex) {
abort();
}
if (!info_ex) {
iv = s->ike.current_iv;
}
new_iv = xallocc(s->ike.ivlen);
gcry_cipher_open(&cry_ctx, s->ike.cry_algo, GCRY_CIPHER_MODE_CBC, 0);
gcry_cipher_setkey(cry_ctx, s->ike.key, s->ike.keylen);
gcry_cipher_setiv(cry_ctx, iv, s->ike.ivlen);
if (!enc) {
memcpy(new_iv, block + blocklen - s->ike.ivlen, s->ike.ivlen);
gcry_cipher_decrypt(cry_ctx, block + ISAKMP_PAYLOAD_O, blocklen - ISAKMP_PAYLOAD_O,
NULL, 0);
if (!info_ex)
memcpy(s->ike.current_iv, new_iv, s->ike.ivlen);
} else {
gcry_cipher_encrypt(cry_ctx, block + ISAKMP_PAYLOAD_O, blocklen - ISAKMP_PAYLOAD_O,
NULL, 0);
if (!info_ex)
memcpy(s->ike.current_iv, block + blocklen - s->ike.ivlen, s->ike.ivlen);
}
gcry_cipher_close(cry_ctx);
free(new_iv);
if (info_ex)
free(iv);
return 0;
}
static uint16_t unpack_verify_phase2(struct sa_block *s, uint8_t * r_packet,
size_t r_length, struct isakmp_packet **r_p, const uint8_t * nonce, size_t nonce_size)
{
struct isakmp_packet *r;
int reject = 0;
*r_p = NULL;
/* Some users report "payload ... not padded..." errors. It seems that they
* are harmless, so ignore and fix the symptom
*/
if (r_length < ISAKMP_PAYLOAD_O ||
((r_length - ISAKMP_PAYLOAD_O) % s->ike.ivlen != 0)) {
DEBUG(2, printf("payload too short or not padded: len=%lld, min=%d (ivlen=%lld)\n",
(long long)r_length, ISAKMP_PAYLOAD_O, (long long)s->ike.ivlen));
hex_dump("Payload", r_packet, r_length, NULL);
if (r_length < ISAKMP_PAYLOAD_O ) {
return ISAKMP_N_UNEQUAL_PAYLOAD_LENGTHS;
}
r_length -= (r_length - ISAKMP_PAYLOAD_O) % s->ike.ivlen;
}
reject = isakmp_crypt(s, r_packet, r_length, 0);
if (reject != 0)
return reject;
s->ike.life.rx += r_length;
{
r = parse_isakmp_packet(r_packet, r_length, &reject);
if (reject != 0) {
if (r) free_isakmp_packet(r);
return reject;
}
}
/* Verify the basic stuff. */
if (r->flags != ISAKMP_FLAG_E) {
free_isakmp_packet(r);
return ISAKMP_N_INVALID_FLAGS;
}
{
size_t sz, spos;
gcry_md_hd_t hm;
unsigned char *expected_hash;
struct isakmp_payload *h = r->payload;
if (h == NULL || h->type != ISAKMP_PAYLOAD_HASH || h->u.hash.length != s->ike.md_len) {
free_isakmp_packet(r);
return ISAKMP_N_INVALID_HASH_INFORMATION;
}
spos = (ISAKMP_PAYLOAD_O + (r_packet[ISAKMP_PAYLOAD_O + 2] << 8)
+ r_packet[ISAKMP_PAYLOAD_O + 3]);
/* Compute the real length based on the payload lengths. */
for (sz = spos; r_packet[sz] != 0; sz += r_packet[sz + 2] << 8 | r_packet[sz + 3]) ;
sz += r_packet[sz + 2] << 8 | r_packet[sz + 3];
gcry_md_open(&hm, s->ike.md_algo, GCRY_MD_FLAG_HMAC);
gcry_md_setkey(hm, s->ike.skeyid_a, s->ike.md_len);
gcry_md_write(hm, r_packet + ISAKMP_MESSAGE_ID_O, 4);
if (nonce)
gcry_md_write(hm, nonce, nonce_size);
gcry_md_write(hm, r_packet + spos, sz - spos);
gcry_md_final(hm);
expected_hash = gcry_md_read(hm, 0);
DEBUG(3,printf("hashlen: %lu\n", (unsigned long)s->ike.md_len));
DEBUG(3,printf("u.hash.length: %d\n", h->u.hash.length));
hex_dump("expected_hash", expected_hash, s->ike.md_len, NULL);
hex_dump("h->u.hash.data", h->u.hash.data, s->ike.md_len, NULL);
reject = 0;
if (crypto_memcmp(h->u.hash.data, expected_hash, s->ike.md_len) != 0)
reject = ISAKMP_N_AUTHENTICATION_FAILED;
gcry_md_close(hm);
#if 0
if (reject != 0) {
free_isakmp_packet(r);
return reject;
}
#endif
}
*r_p = r;
return 0;
}
static void
phase2_authpacket(struct sa_block *s, struct isakmp_payload *pl,
uint8_t exchange_type, uint32_t msgid,
uint8_t ** p_flat, size_t * p_size,
uint8_t * nonce_i, int ni_len, uint8_t * nonce_r, int nr_len)
{
struct isakmp_packet *p;
uint8_t *pl_flat;
size_t pl_size;
gcry_md_hd_t hm;
uint8_t msgid_sent[4];
/* Build up the packet. */
p = new_isakmp_packet();
memcpy(p->i_cookie, s->ike.i_cookie, ISAKMP_COOKIE_LENGTH);
memcpy(p->r_cookie, s->ike.r_cookie, ISAKMP_COOKIE_LENGTH);
p->flags = ISAKMP_FLAG_E;
p->isakmp_version = ISAKMP_VERSION;
p->exchange_type = exchange_type;
p->message_id = msgid;
p->payload = new_isakmp_payload(ISAKMP_PAYLOAD_HASH);
p->payload->next = pl;
p->payload->u.hash.length = s->ike.md_len;
p->payload->u.hash.data = xallocc(s->ike.md_len);
/* Set the MAC. */
gcry_md_open(&hm, s->ike.md_algo, GCRY_MD_FLAG_HMAC);
gcry_md_setkey(hm, s->ike.skeyid_a, s->ike.md_len);
if (pl == NULL) {
DEBUG(3, printf("authing NULL package!\n"));
gcry_md_write(hm, "" /* \0 */ , 1);
}
msgid_sent[0] = msgid >> 24;
msgid_sent[1] = msgid >> 16;
msgid_sent[2] = msgid >> 8;
msgid_sent[3] = msgid;
gcry_md_write(hm, msgid_sent, sizeof(msgid_sent));
if (nonce_i != NULL)
gcry_md_write(hm, nonce_i, ni_len);
if (nonce_r != NULL)
gcry_md_write(hm, nonce_r, nr_len);
if (pl != NULL) {
flatten_isakmp_payloads(pl, &pl_flat, &pl_size);
gcry_md_write(hm, pl_flat, pl_size);
crypto_memzero(pl_flat, pl_size);
free(pl_flat);
}
gcry_md_final(hm);
memcpy(p->payload->u.hash.data, gcry_md_read(hm, 0), s->ike.md_len);
gcry_md_close(hm);
flatten_isakmp_packet(p, p_flat, p_size, s->ike.ivlen);
free_isakmp_packet(p);
}
static void sendrecv_phase2(struct sa_block *s, struct isakmp_payload *pl,
uint8_t exchange_type, uint32_t msgid, int sendonly,
uint8_t * nonce_i, int ni_len, uint8_t * nonce_r, int nr_len)
{
uint8_t *p_flat;
size_t p_size;
ssize_t recvlen;
phase2_authpacket(s, pl, exchange_type, msgid, &p_flat, &p_size,
nonce_i, ni_len, nonce_r, nr_len);
isakmp_crypt(s, p_flat, p_size, 1);
s->ike.life.tx += p_size;
recvlen = sendrecv(s, r_packet, sizeof(r_packet), p_flat, p_size, sendonly);
if (sendonly == 0)
r_length = recvlen;
free(p_flat);
}
void keepalive_ike(struct sa_block *s)
{
uint32_t msgid;
gcry_create_nonce((uint8_t *) & msgid, sizeof(msgid));
sendrecv_phase2(s, NULL, ISAKMP_EXCHANGE_INFORMATIONAL, msgid, 1, 0, 0, 0, 0);
}
static void send_dpd(struct sa_block *s, int isack, uint32_t seqno)
{
struct isakmp_payload *pl;
uint32_t msgid;
pl = new_isakmp_payload(ISAKMP_PAYLOAD_N);
pl->u.n.doi = ISAKMP_DOI_IPSEC;
pl->u.n.protocol = ISAKMP_IPSEC_PROTO_ISAKMP;
pl->u.n.type = isack ? ISAKMP_N_R_U_THERE_ACK : ISAKMP_N_R_U_THERE;
pl->u.n.spi_length = 2 * ISAKMP_COOKIE_LENGTH;
pl->u.n.spi = xallocc(2 * ISAKMP_COOKIE_LENGTH);
memcpy(pl->u.n.spi + ISAKMP_COOKIE_LENGTH * 0, s->ike.i_cookie, ISAKMP_COOKIE_LENGTH);
memcpy(pl->u.n.spi + ISAKMP_COOKIE_LENGTH * 1, s->ike.r_cookie, ISAKMP_COOKIE_LENGTH);
pl->u.n.data_length = 4;
pl->u.n.data = xallocc(4);
*((uint32_t *) pl->u.n.data) = htonl(seqno);
gcry_create_nonce((uint8_t *) & msgid, sizeof(msgid));
/* 2007-09-06 JKU/ZID: Sonicwall drops non hashed r_u_there-requests */
sendrecv_phase2(s, pl, ISAKMP_EXCHANGE_INFORMATIONAL, msgid,
1 , NULL, 0, NULL, 0);
}
void dpd_ike(struct sa_block *s)
{
if (!s->ike.do_dpd)
return;
if (s->ike.dpd_seqno == s->ike.dpd_seqno_ack) {
/* Increase the sequence number, reset the attempts to 6, record
** the current time and send a dpd request
*/
s->ike.dpd_attempts = 6;
s->ike.dpd_sent = time(NULL);
s->ike.dpd_seqno++;
send_dpd(s, 0, s->ike.dpd_seqno);
} else {
/* Our last dpd request has not yet been acked. If it's been
** less than 5 seconds since we sent it do nothing. Otherwise
** decrement dpd_attempts. If dpd_attempts is 0 dpd fails and we
** terminate otherwise we send it again with the same sequence
** number and record current time.
*/
time_t now = time(NULL);
if (now < s->ike.dpd_sent + 5)
return;
if (--s->ike.dpd_attempts == 0) {
DEBUG(2, printf("dead peer detected, terminating\n"));
do_kill = -2;
return;
}
s->ike.dpd_sent = now;
send_dpd(s, 0, s->ike.dpd_seqno);
}
}
static void send_delete_ipsec(struct sa_block *s)
{
/* 2007-08-31 JKU/ZID: Sonicwall doesn't like the chained
* request but wants them split. Cisco does fine with it. */
DEBUGTOP(2, printf("S7.10 send ipsec termination message\n"));
{
struct isakmp_payload *d_ipsec;
uint8_t del_msgid;
gcry_create_nonce((uint8_t *) & del_msgid, sizeof(del_msgid));
d_ipsec = new_isakmp_payload(ISAKMP_PAYLOAD_D);
d_ipsec->u.d.doi = ISAKMP_DOI_IPSEC;
d_ipsec->u.d.protocol = ISAKMP_IPSEC_PROTO_IPSEC_ESP;
d_ipsec->u.d.spi_length = 4;
d_ipsec->u.d.num_spi = 2;
d_ipsec->u.d.spi = xallocc(2 * sizeof(uint8_t *));
d_ipsec->u.d.spi[0] = xallocc(d_ipsec->u.d.spi_length);
memcpy(d_ipsec->u.d.spi[0], &s->ipsec.rx.spi, 4);
d_ipsec->u.d.spi[1] = xallocc(d_ipsec->u.d.spi_length);
memcpy(d_ipsec->u.d.spi[1], &s->ipsec.tx.spi, 4);
sendrecv_phase2(s, d_ipsec, ISAKMP_EXCHANGE_INFORMATIONAL,
del_msgid, 1, NULL, 0, NULL, 0);
}
}
static void send_delete_isakmp(struct sa_block *s)
{
DEBUGTOP(2, printf("S7.11 send isakmp termination message\n"));
{
struct isakmp_payload *d_isakmp;
uint8_t del_msgid;
gcry_create_nonce((uint8_t *) & del_msgid, sizeof(del_msgid));
d_isakmp = new_isakmp_payload(ISAKMP_PAYLOAD_D);
d_isakmp->u.d.doi = ISAKMP_DOI_IPSEC;
d_isakmp->u.d.protocol = ISAKMP_IPSEC_PROTO_ISAKMP;
d_isakmp->u.d.spi_length = 2 * ISAKMP_COOKIE_LENGTH;
d_isakmp->u.d.num_spi = 1;
d_isakmp->u.d.spi = xallocc(1 * sizeof(uint8_t *));
d_isakmp->u.d.spi[0] = xallocc(2 * ISAKMP_COOKIE_LENGTH);
memcpy(d_isakmp->u.d.spi[0] + ISAKMP_COOKIE_LENGTH * 0, s->ike.i_cookie,
ISAKMP_COOKIE_LENGTH);
memcpy(d_isakmp->u.d.spi[0] + ISAKMP_COOKIE_LENGTH * 1, s->ike.r_cookie,
ISAKMP_COOKIE_LENGTH);
sendrecv_phase2(s, d_isakmp, ISAKMP_EXCHANGE_INFORMATIONAL,
del_msgid, 1, NULL, 0, NULL, 0);
}
}
static void phase2_fatal(struct sa_block *s, const char *msg, int id)
{
struct isakmp_payload *pl;
uint32_t msgid;
DEBUG(1, printf("\n\n---!!!!!!!!! entering phase2_fatal !!!!!!!!!---\n\n\n"));
gcry_create_nonce((uint8_t *) & msgid, sizeof(msgid));
pl = new_isakmp_payload(ISAKMP_PAYLOAD_N);
pl->u.n.doi = ISAKMP_DOI_IPSEC;
pl->u.n.protocol = ISAKMP_IPSEC_PROTO_ISAKMP;
pl->u.n.type = id;
sendrecv_phase2(s, pl, ISAKMP_EXCHANGE_INFORMATIONAL, msgid, 1, 0, 0, 0, 0);
send_delete_isakmp(s);
error(1, 0, msg, val_to_string(id, isakmp_notify_enum_array), id);
}
static uint8_t *gen_keymat(struct sa_block *s,
uint8_t protocol, uint32_t spi,
const uint8_t * dh_shared, size_t dh_size,
const uint8_t * ni_data, size_t ni_size, const uint8_t * nr_data, size_t nr_size)
{
gcry_md_hd_t hm;
uint8_t *block;
int i;
int blksz;
int cnt;
blksz = s->ipsec.md_len + s->ipsec.key_len;
cnt = (blksz + s->ike.md_len - 1) / s->ike.md_len;
block = xallocc(cnt * s->ike.md_len);
DEBUG(3, printf("generating %d bytes keymat (cnt=%d)\n", blksz, cnt));
if (cnt < 1)
abort();
for (i = 0; i < cnt; i++) {
gcry_md_open(&hm, s->ike.md_algo, GCRY_MD_FLAG_HMAC);
gcry_md_setkey(hm, s->ike.skeyid_d, s->ike.md_len);
if (i != 0)
gcry_md_write(hm, block + (i - 1) * s->ike.md_len, s->ike.md_len);
if (dh_shared != NULL)
gcry_md_write(hm, dh_shared, dh_size);
gcry_md_write(hm, &protocol, 1);
gcry_md_write(hm, (uint8_t *) & spi, sizeof(spi));
gcry_md_write(hm, ni_data, ni_size);
gcry_md_write(hm, nr_data, nr_size);
gcry_md_final(hm);
memcpy(block + i * s->ike.md_len, gcry_md_read(hm, 0), s->ike.md_len);
gcry_md_close(hm);
}
return block;
}
static int mask_to_masklen(struct in_addr mask)
{
int len;
uint32_t addr;
addr = ntohl(mask.s_addr);
for (len = 0; addr; addr <<= 1, len++)
;
return len;
}
static int do_config_to_env(struct sa_block *s, struct isakmp_attribute *a)
{
int i;
int reject = 0;
int seen_address = 0;
char *strbuf, *strbuf2;
int ret;
unsetenv("CISCO_BANNER");
unsetenv("CISCO_DEF_DOMAIN");
unsetenv("CISCO_SPLIT_DNS");
unsetenv("CISCO_SPLIT_INC");
unsetenv("CISCO_IPV6_SPLIT_INC");
unsetenv("INTERNAL_IP4_NBNS");
unsetenv("INTERNAL_IP4_DNS");
unsetenv("INTERNAL_IP4_NETMASK");
unsetenv("INTERNAL_IP4_ADDRESS");
unsetenv("INTERNAL_IP6_DNS");
unsetenv("INTERNAL_IP6_NETMASK");
unsetenv("INTERNAL_IP6_ADDRESS");
for (; a && reject == 0; a = a->next)
switch (a->type) {
case ISAKMP_MODECFG_ATTRIB_INTERNAL_IP4_ADDRESS:
if (a->af != isakmp_attr_lots || a->u.lots.length != 4)
reject = ISAKMP_N_ATTRIBUTES_NOT_SUPPORTED;
else {
addenv_ipv4("INTERNAL_IP4_ADDRESS", a->u.lots.data);
memcpy(&s->our_address, a->u.lots.data, 4);
}
seen_address = 1;
break;