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/*
* This is the main module of the CNTLM
*
* CNTLM 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.
*
* CNTLM 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., 51 Franklin
* St, Fifth Floor, Boston, MA 02110-1301, USA.
*
* Copyright (c) 2007 David Kubicek
*
*/
#include <sys/types.h>
#include <sys/time.h>
#include <sys/select.h>
#include <sys/stat.h>
#include <sys/socket.h>
#include <pthread.h>
#include <stdio.h>
#include <errno.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <signal.h>
#include <unistd.h>
#include <stdlib.h>
#include <string.h>
#include <strings.h>
#include <netdb.h>
#include <ctype.h>
#include <pwd.h>
#include <fcntl.h>
#include <syslog.h>
#include <termios.h>
#include <fnmatch.h>
/*
* Some helping routines like linked list manipulation substr(), memory
* allocation, NTLM authentication routines, etc.
*/
#include "config/config.h"
#include "socket.h"
#include "utils.h"
#include "ntlm.h"
#include "swap.h"
#include "config.h"
#include "acl.h"
#include "auth.h"
#include "http.h"
#include "globals.h"
#include "pages.h"
#include "forward.h" /* code serving via parent proxy */
#include "direct.h" /* code serving directly without proxy */
#define STACK_SIZE sizeof(void *)*8*1024
/*
* Global "read-only" data initialized in main(). Comments list funcs. which use
* them. Having these global avoids the need to pass them to each thread and
* from there again a few times to inner calls.
*/
int debug = 0; /* all debug printf's and possibly external modules */
struct auth_s *g_creds = NULL; /* throughout the whole module */
int quit = 0; /* sighandler() */
int ntlmbasic = 0; /* forward_request() */
int serialize = 0;
int scanner_plugin = 0;
long scanner_plugin_maxsize = 0;
/*
* List of finished threads. Each forward_request() thread adds itself to it when
* finished. Main regularly joins and removes all tid's in there.
*/
plist_t threads_list = NULL;
pthread_mutex_t threads_mtx = PTHREAD_MUTEX_INITIALIZER;
/*
* List of cached connections. Accessed by each thread forward_request().
*/
plist_t connection_list = NULL;
pthread_mutex_t connection_mtx = PTHREAD_MUTEX_INITIALIZER;
/*
* List of available proxies and current proxy id for proxy_connect().
*/
int parent_count = 0;
plist_t parent_list = NULL;
/*
* List of custom header substitutions, SOCKS5 proxy users and
* UserAgents for the scanner plugin.
*/
hlist_t header_list = NULL; /* forward_request() */
hlist_t users_list = NULL; /* socks5_thread() */
plist_t scanner_agent_list = NULL; /* scanner_hook() */
plist_t noproxy_list = NULL; /* proxy_thread() */
/*
* General signal handler. If in debug mode, quit immediately.
*/
void sighandler(int p) {
if (!quit)
syslog(LOG_INFO, "Signal %d received, issuing clean shutdown\n", p);
else
syslog(LOG_INFO, "Signal %d received, forcing shutdown\n", p);
if (quit++ || debug)
quit++;
}
/*
* Parse proxy parameter and add it to the global list.
*/
int parent_add(char *parent, int port) {
int len, i;
char *proxy;
proxy_t *aux;
/*
* Check format and parse it.
*/
proxy = strdup(parent);
len = strlen(proxy);
i = strcspn(proxy, ": ");
if (i != len) {
proxy[i++] = 0;
while (i < len && (proxy[i] == ' ' || proxy[i] == '\t'))
i++;
if (i >= len) {
free(proxy);
return 0;
}
port = atoi(proxy+i);
}
/*
* No port argument and not parsed from proxy?
*/
if (!port) {
syslog(LOG_ERR, "Invalid proxy specification %s.\n", parent);
free(proxy);
myexit(1);
}
/*
* Try to resolve proxy address
*
if (debug)
syslog(LOG_INFO, "Resolving proxy %s...\n", proxy);
if (!so_resolv(&host, proxy)) {
syslog(LOG_ERR, "Cannot resolve proxy %s, discarding.\n", parent);
free(proxy);
return 0;
}
*/
aux = (proxy_t *)new(sizeof(proxy_t));
strlcpy(aux->hostname, proxy, sizeof(aux->hostname));
aux->port = port;
aux->resolved = 0;
parent_list = plist_add(parent_list, ++parent_count, (char *)aux);
free(proxy);
return 1;
}
/*
* Register and bind new proxy service port.
*/
void listen_add(const char *service, plist_t *list, char *spec, int gateway) {
struct in_addr source;
int i, p, len, port;
char *tmp;
len = strlen(spec);
p = strcspn(spec, ":");
if (p < len-1) {
tmp = substr(spec, 0, p);
if (!so_resolv(&source, tmp)) {
syslog(LOG_ERR, "Cannot resolve listen address %s\n", tmp);
myexit(1);
}
free(tmp);
port = atoi(tmp = spec+p+1);
} else {
source.s_addr = htonl(gateway ? INADDR_ANY : INADDR_LOOPBACK);
port = atoi(tmp = spec);
}
if (!port) {
syslog(LOG_ERR, "Invalid listen port %s.\n", tmp);
myexit(1);
}
i = so_listen(port, source);
if (i > 0) {
*list = plist_add(*list, i, NULL);
syslog(LOG_INFO, "%s listening on %s:%d\n", service, inet_ntoa(source), port);
}
}
/*
* Register a new tunnel definition, bind service port.
*/
void tunnel_add(plist_t *list, char *spec, int gateway) {
struct in_addr source;
int i, len, count, pos, port;
char *field[4];
char *tmp;
spec = strdup(spec);
len = strlen(spec);
field[0] = spec;
for (count = 1, i = 0; count < 4 && i < len; ++i)
if (spec[i] == ':') {
spec[i] = 0;
field[count++] = spec+i+1;
}
pos = 0;
if (count == 4) {
if (!so_resolv(&source, field[pos])) {
syslog(LOG_ERR, "Cannot resolve tunel bind address: %s\n", field[pos]);
myexit(1);
}
pos++;
} else
source.s_addr = htonl(gateway ? INADDR_ANY : INADDR_LOOPBACK);
if (count-pos == 3) {
port = atoi(field[pos]);
if (port == 0) {
syslog(LOG_ERR, "Invalid tunnel local port: %s\n", field[pos]);
myexit(1);
}
if (!strlen(field[pos+1]) || !strlen(field[pos+2])) {
syslog(LOG_ERR, "Invalid tunnel target: %s:%s\n", field[pos+1], field[pos+2]);
myexit(1);
}
tmp = new(strlen(field[pos+1]) + strlen(field[pos+2]) + 2 + 1);
strcpy(tmp, field[pos+1]);
strcat(tmp, ":");
strcat(tmp, field[pos+2]);
i = so_listen(port, source);
if (i > 0) {
*list = plist_add(*list, i, tmp);
syslog(LOG_INFO, "New tunnel from %s:%d to %s\n", inet_ntoa(source), port, tmp);
} else
free(tmp);
} else {
printf("Tunnel specification incorrect ([laddress:]lport:rserver:rport).\n");
myexit(1);
}
free(spec);
}
/*
* Add no-proxy hostname/IP
*/
plist_t noproxy_add(plist_t list, char *spec) {
char *tok, *save;
tok = strtok_r(spec, ", ", &save);
while ( tok != NULL ) {
if (debug)
printf("Adding no-proxy for: '%s'\n", tok);
list = plist_add(list, 0, strdup(tok));
tok = strtok_r(NULL, ", ", &save);
}
return list;
}
int noproxy_match(const char *addr) {
plist_t list;
list = noproxy_list;
while (list) {
if (list->aux && strlen(list->aux)
&& fnmatch(list->aux, addr, 0) == 0) {
if (debug)
printf("MATCH: %s (%s)\n", addr, (char *)list->aux);
return 1;
} else if (debug)
printf(" NO: %s (%s)\n", addr, (char *)list->aux);
list = list->next;
}
return 0;
}
/*
* Proxy thread - decide between direct and forward based on NoProxy
*/
void *proxy_thread(void *thread_data) {
rr_data_t request, ret;
int keep_alive; /* Proxy-Connection */
int cd = ((struct thread_arg_s *)thread_data)->fd;
do {
ret = NULL;
keep_alive = 0;
if (debug) {
printf("\n******* Round 1 C: %d *******\n", cd);
printf("Reading headers (%d)...\n", cd);
}
request = new_rr_data();
if (!headers_recv(cd, request)) {
free_rr_data(request);
break;
}
do {
/*
* Are we being returned a request by forward_request or direct_request?
*/
if (ret) {
free_rr_data(request);
request = ret;
}
keep_alive = hlist_subcmp(request->headers, "Proxy-Connection", "keep-alive");
if (noproxy_match(request->hostname))
ret = direct_request(thread_data, request);
else
ret = forward_request(thread_data, request);
if (debug)
printf("proxy_thread: request rc = %p\n", (void *)ret);
} while (ret != NULL && ret != (void *)-1);
free_rr_data(request);
/*
* If client asked for proxy keep-alive, loop unless the last server response
* requested (Proxy-)Connection: close.
*/
} while (keep_alive && ret != (void *)-1 && !serialize);
/*
* Add ourselves to the "threads to join" list.
*/
if (!serialize) {
pthread_mutex_lock(&threads_mtx);
threads_list = plist_add(threads_list, (unsigned long)pthread_self(), NULL);
pthread_mutex_unlock(&threads_mtx);
}
free(thread_data);
close(cd);
return NULL;
}
/*
* Tunnel/port forward thread - this method is obviously better solution than using extra
* tools like "corkscrew" which after all require us for authentication and tunneling
* their HTTP CONNECT in the first place.
*/
void *tunnel_thread(void *thread_data) {
char *hostname, *pos;
char *thost = ((struct thread_arg_s *)thread_data)->target;
hostname = strdup(thost);
if ((pos = strchr(hostname, ':')) != NULL)
*pos = 0;
if (noproxy_match(hostname))
direct_tunnel(thread_data);
else
forward_tunnel(thread_data);
free(hostname);
free(thread_data);
/*
* Add ourself to the "threads to join" list.
*/
pthread_mutex_lock(&threads_mtx);
threads_list = plist_add(threads_list, (unsigned long)pthread_self(), NULL);
pthread_mutex_unlock(&threads_mtx);
return NULL;
}
/*
* SOCKS5 thread
*/
void *socks5_thread(void *thread_data) {
char *tmp, *thost, *tport, *uname, *upass;
unsigned short port;
int ver, r, c, i, w;
struct auth_s *tcreds = NULL;
unsigned char *bs = NULL, *auths = NULL, *addr = NULL;
int found = -1;
int sd = -1;
int open = !hlist_count(users_list);
int cd = ((struct thread_arg_s *)thread_data)->fd;
struct sockaddr_in caddr = ((struct thread_arg_s *)thread_data)->addr;
free(thread_data);
/*
* Check client's version, possibly fuck'em
*/
bs = (unsigned char *)new(10);
thost = new(MINIBUF_SIZE);
tport = new(MINIBUF_SIZE);
r = read(cd, bs, 2);
if (r != 2 || bs[0] != 5)
goto bailout;
/*
* Read offered auth schemes
*/
c = bs[1];
auths = (unsigned char *)new(c+1);
r = read(cd, auths, c);
if (r != c)
goto bailout;
/*
* Are we wide open and client is OK with no auth?
*/
if (open) {
for (i = 0; i < c && (auths[i] || (found = 0)); ++i);
}
/*
* If not, accept plain auth if offered
*/
if (found < 0) {
for (i = 0; i < c && (auths[i] != 2 || !(found = 2)); ++i);
}
/*
* If not open and no auth offered or open and auth requested, fuck'em
* and complete the handshake
*/
if (found < 0) {
bs[0] = 5;
bs[1] = 0xFF;
w = write(cd, bs, 2);
goto bailout;
} else {
bs[0] = 5;
bs[1] = found;
w = write(cd, bs, 2);
}
/*
* Plain auth negotiated?
*/
if (found != 0) {
/*
* Check ver and read username len
*/
r = read(cd, bs, 2);
if (r != 2) {
bs[0] = 1;
bs[1] = 0xFF; /* Unsuccessful (not supported) */
w = write(cd, bs, 2);
goto bailout;
}
c = bs[1];
/*
* Read username and pass len
*/
uname = new(c+1);
r = read(cd, uname, c+1);
if (r != c+1) {
free(uname);
goto bailout;
}
i = uname[c];
uname[c] = 0;
c = i;
/*
* Read pass
*/
upass = new(c+1);
r = read(cd, upass, c);
if (r != c) {
free(upass);
free(uname);
goto bailout;
}
upass[c] = 0;
/*
* Check credentials against the list
*/
tmp = hlist_get(users_list, uname);
if (!hlist_count(users_list) || (tmp && !strcmp(tmp, upass))) {
bs[0] = 1;
bs[1] = 0; /* Success */
} else {
bs[0] = 1;
bs[1] = 0xFF; /* Failed */
}
/*
* Send response
*/
w = write(cd, bs, 2);
free(upass);
free(uname);
/*
* Fuck'em if auth failed
*/
if (bs[1])
goto bailout;
}
/*
* Read request type
*/
r = read(cd, bs, 4);
if (r != 4)
goto bailout;
/*
* Is it connect for supported address type (IPv4 or DNS)? If not, fuck'em
*/
if (bs[1] != 1 || (bs[3] != 1 && bs[3] != 3)) {
bs[0] = 5;
bs[1] = 2; /* Not allowed */
bs[2] = 0;
bs[3] = 1; /* Dummy IPv4 */
memset(bs+4, 0, 6);
w = write(cd, bs, 10);
goto bailout;
}
/*
* Ok, it's connect to a domain or IP
* Let's read dest address
*/
if (bs[3] == 1) {
ver = 1; /* IPv4, we know the length */
c = 4;
} else if (bs[3] == 3) {
ver = 2; /* FQDN, get string length */
r = read(cd, &c, 1);
if (r != 1)
goto bailout;
} else
goto bailout;
addr = (unsigned char *)new(c+10 + 1);
r = read(cd, addr, c);
if (r != c)
goto bailout;
addr[c] = 0;
/*
* Convert the address to character string
*/
if (ver == 1) {
sprintf(thost, "%d.%d.%d.%d", addr[0], addr[1], addr[2], addr[3]); /* It's in network byte order */
} else {
strlcpy(thost, (char *)addr, MINIBUF_SIZE);
}
/*
* Read port number and convert to host byte order int
*/
r = read(cd, &port, 2);
if (r != 2)
goto bailout;
i = 0;
if (noproxy_match(thost)) {
sd = host_connect(thost, ntohs(port));
i = (sd >= 0);
} else {
sprintf(tport, "%d", ntohs(port));
strlcat(thost, ":", MINIBUF_SIZE);
strlcat(thost, tport, MINIBUF_SIZE);
tcreds = new_auth();
sd = proxy_connect(tcreds);
if (sd >= 0)
i = prepare_http_connect(sd, tcreds, thost);
}
/*
* Direct or proxy connect?
*/
if (!i) {
/*
* Connect/tunnel failed, report
*/
bs[0] = 5;
bs[1] = 1; /* General failure */
bs[2] = 0;
bs[3] = 1; /* Dummy IPv4 */
memset(bs+4, 0, 6);
w = write(cd, bs, 10);
goto bailout;
} else {
/*
* All right
*/
bs[0] = 5;
bs[1] = 0; /* Success */
bs[2] = 0;
bs[3] = 1; /* Dummy IPv4 */
memset(bs+4, 0, 6);
w = write(cd, bs, 10);
}
syslog(LOG_DEBUG, "%s SOCKS %s", inet_ntoa(caddr.sin_addr), thost);
/*
* Let's give them bi-directional connection they asked for
*/
tunnel(cd, sd);
bailout:
if (addr)
free(addr);
if (auths)
free(auths);
if (thost)
free(thost);
if (tport)
free(tport);
if (bs)
free(bs);
if (tcreds)
free(tcreds);
if (sd)
close(sd);
close(cd);
return NULL;
}
int main(int argc, char **argv) {
char *tmp, *head;
char *cpassword, *cpassntlm2, *cpassnt, *cpasslm;
char *cuser, *cdomain, *cworkstation, *cuid, *cpidfile, *cauth;
struct passwd *pw;
struct termios termold, termnew;
pthread_attr_t pattr;
pthread_t pthr;
hlist_t list;
int i, w;
int cd = 0;
int help = 0;
int nuid = 0;
int ngid = 0;
int gateway = 0;
int tc = 0;
int tj = 0;
int interactivepwd = 0;
int interactivehash = 0;
int tracefile = 0;
int cflags = 0;
int asdaemon = 1;
plist_t tunneld_list = NULL;
plist_t proxyd_list = NULL;
plist_t socksd_list = NULL;
plist_t rules = NULL;
config_t cf = NULL;
char *magic_detect = NULL;
g_creds = new_auth();
cuser = new(MINIBUF_SIZE);
cdomain = new(MINIBUF_SIZE);
cpassword = new(MINIBUF_SIZE);
cpassntlm2 = new(MINIBUF_SIZE);
cpassnt = new(MINIBUF_SIZE);
cpasslm = new(MINIBUF_SIZE);
cworkstation = new(MINIBUF_SIZE);
cpidfile = new(MINIBUF_SIZE);
cuid = new(MINIBUF_SIZE);
cauth = new(MINIBUF_SIZE);
openlog("cntlm", LOG_CONS, LOG_DAEMON);
#if config_endian == 0
syslog(LOG_INFO, "Starting cntlm version " VERSION " for BIG endian\n");
#else
syslog(LOG_INFO, "Starting cntlm version " VERSION " for LITTLE endian\n");
#endif
while ((i = getopt(argc, argv, ":-:a:c:d:fghIl:p:r:su:vw:A:BD:F:G:HL:M:N:O:P:R:S:T:U:")) != -1) {
switch (i) {
case 'A':
case 'D':
if (!acl_add(&rules, optarg, (i == 'A' ? ACL_ALLOW : ACL_DENY)))
myexit(1);
break;
case 'a':
strlcpy(cauth, optarg, MINIBUF_SIZE);
break;
case 'B':
ntlmbasic = 1;
break;
case 'c':
if (!(cf = config_open(optarg))) {
syslog(LOG_ERR, "Cannot access specified config file: %s\n", optarg);
myexit(1);
}
break;
case 'd':
strlcpy(cdomain, optarg, MINIBUF_SIZE);
break;
case 'F':
cflags = swap32(strtoul(optarg, &tmp, 0));
break;
case 'f':
asdaemon = 0;
break;
case 'G':
if (strlen(optarg)) {
scanner_plugin = 1;
if (!scanner_plugin_maxsize)
scanner_plugin_maxsize = 1;
i = strlen(optarg) + 3;
tmp = new(i);
snprintf(tmp, i, "*%s*", optarg);
scanner_agent_list = plist_add(scanner_agent_list, 0, tmp);
}
break;
case 'g':
gateway = 1;
break;
case 'H':
interactivehash = 1;
break;
case 'I':
interactivepwd = 1;
break;
case 'L':
/*
* Parse and validate the argument.
* Create a listening socket for tunneling.
*/
tunnel_add(&tunneld_list, optarg, gateway);
break;
case 'l':
/*
* Create a listening socket for proxy function.
*/
listen_add("Proxy", &proxyd_list, optarg, gateway);
break;
case 'M':
magic_detect = strdup(optarg);
break;
case 'N':
noproxy_list = noproxy_add(noproxy_list, tmp=strdup(optarg));
free(tmp);
break;
case 'O':
listen_add("SOCKS5 proxy", &socksd_list, optarg, gateway);
break;
case 'P':
strlcpy(cpidfile, optarg, MINIBUF_SIZE);
break;
case 'p':
/*
* Overwrite the password parameter with '*'s to make it
* invisible in "ps", /proc, etc.
*/
strlcpy(cpassword, optarg, MINIBUF_SIZE);
for (i = strlen(optarg)-1; i >= 0; --i)
optarg[i] = '*';
break;
case 'R':
tmp = strdup(optarg);
head = strchr(tmp, ':');
if (!head) {
fprintf(stderr, "Invalid username:password format for -R: %s\n", tmp);
} else {
head[0] = 0;
users_list = hlist_add(users_list, tmp, head+1,
HLIST_ALLOC, HLIST_ALLOC);
}
break;
case 'r':
if (is_http_header(optarg))
header_list = hlist_add(header_list,
get_http_header_name(optarg),
get_http_header_value(optarg),
HLIST_NOALLOC, HLIST_NOALLOC);
break;
case 'S':
scanner_plugin = 1;
scanner_plugin_maxsize = atol(optarg);
break;
case 's':
/*
* Do not use threads - for debugging purposes only
*/
serialize = 1;
break;
case 'T':
tracefile = open(optarg, O_CREAT | O_TRUNC | O_WRONLY, 0600);
if (tracefile < 0) {
fprintf(stderr, "Cannot create trace file.\n");
myexit(1);
} else {
printf("Redirecting all output to %s\n", optarg);
dup2(tracefile, 1);
dup2(tracefile, 2);
printf("Cntlm debug trace, version " VERSION);
#ifdef __CYGWIN__
printf(" windows/cygwin port");
#endif
printf(".\nCommand line: ");
for (i = 0; i < argc; ++i)
printf("%s ", argv[i]);
printf("\n");
}
break;
case 'U':
strlcpy(cuid, optarg, MINIBUF_SIZE);
break;
case 'u':
i = strcspn(optarg, "@");
if (i != strlen(optarg)) {
strlcpy(cuser, optarg, MIN(MINIBUF_SIZE, i+1));
strlcpy(cdomain, optarg+i+1, MINIBUF_SIZE);
} else {
strlcpy(cuser, optarg, MINIBUF_SIZE);
}
break;
case 'v':
debug = 1;
asdaemon = 0;
openlog("cntlm", LOG_CONS | LOG_PERROR, LOG_DAEMON);
break;
case 'w':
strlcpy(cworkstation, optarg, MINIBUF_SIZE);
break;
case 'h':
default:
help = 1;
}
}
/*
* Help requested?
*/
if (help) {
printf("CNTLM - Accelerating NTLM Authentication Proxy version " VERSION "\n");
printf("Copyright (c) 2oo7-2o1o David Kubicek\n\n"
"This program comes with NO WARRANTY, to the extent permitted by law. You\n"
"may redistribute copies of it under the terms of the GNU GPL Version 2 or\n"
"newer. For more information about these matters, see the file LICENSE.\n"
"For copyright holders of included encryption routines see headers.\n\n");
fprintf(stderr, "Usage: %s [-AaBcDdFfgHhILlMPpSsTUuvw] <proxy_host>[:]<proxy_port> ...\n", argv[0]);
fprintf(stderr, "\t-A <address>[/<net>]\n"
"\t ACL allow rule. IP or hostname, net must be a number (CIDR notation)\n");
fprintf(stderr, "\t-a ntlm | nt | lm\n"
"\t Authentication type - combined NTLM, just LM, or just NT. Default NTLM.\n"
"\t It is the most versatile setting and likely to work for you.\n");
fprintf(stderr, "\t-B Enable NTLM-to-basic authentication.\n");
fprintf(stderr, "\t-c <config_file>\n"
"\t Configuration file. Other arguments can be used as well, overriding\n"
"\t config file settings.\n");
fprintf(stderr, "\t-D <address>[/<net>]\n"
"\t ACL deny rule. Syntax same as -A.\n");
fprintf(stderr, "\t-d <domain>\n"
"\t Domain/workgroup can be set separately.\n");
fprintf(stderr, "\t-f Run in foreground, do not fork into daemon mode.\n");
fprintf(stderr, "\t-F <flags>\n"
"\t NTLM authentication flags.\n");
fprintf(stderr, "\t-G <pattern>\n"
"\t User-Agent matching for the trans-isa-scan plugin.\n");
fprintf(stderr, "\t-g Gateway mode - listen on all interfaces, not only loopback.\n");
fprintf(stderr, "\t-H Print password hashes for use in config file (NTLMv2 needs -u and -d).\n");
fprintf(stderr, "\t-h Print this help info along with version number.\n");
fprintf(stderr, "\t-I Prompt for the password interactively.\n");
fprintf(stderr, "\t-L [<saddr>:]<lport>:<rhost>:<rport>\n"
"\t Forwarding/tunneling a la OpenSSH. Same syntax - listen on lport\n"
"\t and forward all connections through the proxy to rhost:rport.\n"
"\t Can be used for direct tunneling without corkscrew, etc.\n");
fprintf(stderr, "\t-l [<saddr>:]<lport>\n"
"\t Main listening port for the NTLM proxy.\n");
fprintf(stderr, "\t-M <testurl>\n"
"\t Magic autodetection of proxy's NTLM dialect.\n");
fprintf(stderr, "\t-N \"<hostname_wildcard1>[, <hostname_wildcardN>\"\n"
"\t List of URL's to serve direcly as stand-alone proxy (e.g. '*.local')\n");
fprintf(stderr, "\t-O [<saddr>:]<lport>\n"
"\t Enable SOCKS5 proxy on port lport (binding to address saddr)\n");
fprintf(stderr, "\t-P <pidfile>\n"
"\t Create a PID file upon successful start.\n");
fprintf(stderr, "\t-p <password>\n"
"\t Account password. Will not be visible in \"ps\", /proc, etc.\n");
fprintf(stderr, "\t-r \"HeaderName: value\"\n"
"\t Add a header substitution. All such headers will be added/replaced\n"
"\t in the client's requests.\n");
fprintf(stderr, "\t-S <size_in_kb>\n"
"\t Enable automation of GFI WebMonitor ISA scanner for files < size_in_kb.\n");
fprintf(stderr, "\t-s Do not use threads, serialize all requests - for debugging only.\n");
fprintf(stderr, "\t-U <uid>\n"
"\t Run as uid. It is an important security measure not to run as root.\n");
fprintf(stderr, "\t-u <user>[@<domain]\n"
"\t Domain/workgroup can be set separately.\n");
fprintf(stderr, "\t-v Print debugging information.\n");
fprintf(stderr, "\t-w <workstation>\n"
"\t Some proxies require correct NetBIOS hostname.\n\n");
exit(1);
}
/*
* More arguments on the command-line? Must be proxies.
*/
i = optind;
while (i < argc) {
tmp = strchr(argv[i], ':');
parent_add(argv[i], !tmp && i+1 < argc ? atoi(argv[i+1]) : 0);
i += (!tmp ? 2 : 1);
}
/*
* No configuration file yet? Load the default.
*/
#ifdef SYSCONFDIR
if (!cf) {
#ifdef __CYGWIN__
tmp = getenv("PROGRAMFILES(X86)");
if (tmp == NULL || strlen(tmp) == 0)
tmp = getenv("PROGRAMFILES");
if (tmp == NULL)
tmp = "C:\\Program Files";
head = new(MINIBUF_SIZE);
strlcpy(head, tmp, MINIBUF_SIZE);
strlcat(head, "\\Cntlm\\cntlm.ini", MINIBUF_SIZE);
cf = config_open(head);
#else
cf = config_open(SYSCONFDIR "/cntlm.conf");
#endif
if (debug) {
if (cf)
printf("Default config file opened successfully\n");
else
syslog(LOG_ERR, "Could not open default config file\n");
}
}
#endif
/*
* If any configuration file was successfully opened, parse it.
*/
if (cf) {
/*
* Check if gateway mode is requested before actually binding any ports.
*/
tmp = new(MINIBUF_SIZE);
CFG_DEFAULT(cf, "Gateway", tmp, MINIBUF_SIZE);
if (!strcasecmp("yes", tmp))
gateway = 1;
free(tmp);
/*
* Check for NTLM-to-basic settings
*/
tmp = new(MINIBUF_SIZE);
CFG_DEFAULT(cf, "NTLMToBasic", tmp, MINIBUF_SIZE);
if (!strcasecmp("yes", tmp))
ntlmbasic = 1;
free(tmp);
/*
* Setup the rest of tunnels.
*/
while ((tmp = config_pop(cf, "Tunnel"))) {
tunnel_add(&tunneld_list, tmp, gateway);
free(tmp);
}
/*
* Bind the rest of proxy service ports.
*/
while ((tmp = config_pop(cf, "Listen"))) {
listen_add("Proxy", &proxyd_list, tmp, gateway);
free(tmp);
}
/*
* Bind the rest of SOCKS5 service ports.
*/
while ((tmp = config_pop(cf, "SOCKS5Proxy"))) {
listen_add("SOCKS5 proxy", &socksd_list, tmp, gateway);
free(tmp);
}
/*
* Accept only headers not specified on the command line.
* Command line has higher priority.
*/
while ((tmp = config_pop(cf, "Header"))) {
if (is_http_header(tmp)) {
head = get_http_header_name(tmp);
if (!hlist_in(header_list, head))
header_list = hlist_add(header_list, head, get_http_header_value(tmp),
HLIST_ALLOC, HLIST_NOALLOC);
free(head);
} else
syslog(LOG_ERR, "Invalid header format: %s\n", tmp);
free(tmp);
}
/*
* Add the rest of parent proxies.
*/
while ((tmp = config_pop(cf, "Proxy"))) {
parent_add(tmp, 0);
free(tmp);
}
/*
* No ACLs on the command line? Use config file.
*/
if (rules == NULL) {
list = cf->options;
while (list) {
if (!(i=strcasecmp("Allow", list->key)) || !strcasecmp("Deny", list->key))
if (!acl_add(&rules, list->value, i ? ACL_DENY : ACL_ALLOW))
myexit(1);
list = list->next;
}
while ((tmp = config_pop(cf, "Allow")))
free(tmp);
while ((tmp = config_pop(cf, "Deny")))
free(tmp);
}
/*
* Single options.
*/
CFG_DEFAULT(cf, "Auth", cauth, MINIBUF_SIZE);
CFG_DEFAULT(cf, "Domain", cdomain, MINIBUF_SIZE);
CFG_DEFAULT(cf, "Password", cpassword, MINIBUF_SIZE);
CFG_DEFAULT(cf, "PassNTLMv2", cpassntlm2, MINIBUF_SIZE);
CFG_DEFAULT(cf, "PassNT", cpassnt, MINIBUF_SIZE);
CFG_DEFAULT(cf, "PassLM", cpasslm, MINIBUF_SIZE);
CFG_DEFAULT(cf, "Username", cuser, MINIBUF_SIZE);
CFG_DEFAULT(cf, "Workstation", cworkstation, MINIBUF_SIZE);
tmp = new(MINIBUF_SIZE);
CFG_DEFAULT(cf, "Flags", tmp, MINIBUF_SIZE);
if (!cflags)
cflags = swap32(strtoul(tmp, NULL, 0));
free(tmp);
tmp = new(MINIBUF_SIZE);
CFG_DEFAULT(cf, "ISAScannerSize", tmp, MINIBUF_SIZE);
if (!scanner_plugin_maxsize && strlen(tmp)) {
scanner_plugin = 1;
scanner_plugin_maxsize = atoi(tmp);
}
free(tmp);
while ((tmp = config_pop(cf, "NoProxy"))) {
if (strlen(tmp)) {
noproxy_list = noproxy_add(noproxy_list, tmp);
}
free(tmp);
}
while ((tmp = config_pop(cf, "SOCKS5Users"))) {
head = strchr(tmp, ':');
if (!head) {
syslog(LOG_ERR, "Invalid username:password format for SOCKS5User: %s\n", tmp);
} else {
head[0] = 0;
users_list = hlist_add(users_list, tmp, head+1, HLIST_ALLOC, HLIST_ALLOC);
}
}
/*
* Add User-Agent matching patterns.
*/
while ((tmp = config_pop(cf, "ISAScannerAgent"))) {
scanner_plugin = 1;
if (!scanner_plugin_maxsize)
scanner_plugin_maxsize = 1;
if ((i = strlen(tmp))) {
head = new(i + 3);
snprintf(head, i+3, "*%s*", tmp);
scanner_agent_list = plist_add(scanner_agent_list, 0, head);
}
free(tmp);
}
/*
* Print out unused/unknown options.
*/
list = cf->options;
while (list) {
syslog(LOG_INFO, "Ignoring config file option: %s\n", list->key);
list = list->next;
}
}
config_close(cf);
if (!interactivehash && !parent_list)
croak("Parent proxy address missing.\n", interactivepwd || magic_detect);
if (!interactivehash && !magic_detect && !proxyd_list)
croak("No proxy service ports were successfully opened.\n", interactivepwd);
/*
* Set default value for the workstation. Hostname if possible.
*/
if (!strlen(cworkstation)) {
#if config_gethostname == 1
gethostname(cworkstation, MINIBUF_SIZE);
#endif
if (!strlen(cworkstation))
strlcpy(cworkstation, "cntlm", MINIBUF_SIZE);
syslog(LOG_INFO, "Workstation name used: %s\n", cworkstation);
}
/*
* Parse selected NTLM hash combination.
*/
if (strlen(cauth)) {
if (!strcasecmp("ntlm", cauth)) {
g_creds->hashnt = 1;
g_creds->hashlm = 1;
g_creds->hashntlm2 = 0;
} else if (!strcasecmp("nt", cauth)) {
g_creds->hashnt = 1;
g_creds->hashlm = 0;
g_creds->hashntlm2 = 0;
} else if (!strcasecmp("lm", cauth)) {
g_creds->hashnt = 0;
g_creds->hashlm = 1;
g_creds->hashntlm2 = 0;
} else if (!strcasecmp("ntlmv2", cauth)) {
g_creds->hashnt = 0;
g_creds->hashlm = 0;
g_creds->hashntlm2 = 1;
} else if (!strcasecmp("ntlm2sr", cauth)) {
g_creds->hashnt = 2;
g_creds->hashlm = 0;
g_creds->hashntlm2 = 0;
} else {
syslog(LOG_ERR, "Unknown NTLM auth combination.\n");
myexit(1);
}
}
if (socksd_list && !users_list)
syslog(LOG_WARNING, "SOCKS5 proxy will NOT require any authentication\n");
if (!magic_detect)
syslog(LOG_INFO, "Using following NTLM hashes: NTLMv2(%d) NT(%d) LM(%d)\n",
g_creds->hashntlm2, g_creds->hashnt, g_creds->hashlm);
if (cflags) {
syslog(LOG_INFO, "Using manual NTLM flags: 0x%X\n", swap32(cflags));
g_creds->flags = cflags;
}
/*
* Last chance to get password from the user
*/
if (interactivehash || magic_detect || (interactivepwd && !ntlmbasic)) {
printf("Password: ");
tcgetattr(0, &termold);
termnew = termold;
termnew.c_lflag &= ~(ISIG | ECHO);
tcsetattr(0, TCSADRAIN, &termnew);
tmp = fgets(cpassword, MINIBUF_SIZE, stdin);
tcsetattr(0, TCSADRAIN, &termold);
i = strlen(cpassword) - 1;
if (cpassword[i] == '\n') {
cpassword[i] = 0;
if (cpassword[i - 1] == '\r')
cpassword[i - 1] = 0;
}
printf("\n");
}
/*
* Convert optional PassNT, PassLM and PassNTLMv2 strings to hashes
* unless plaintext pass was used, which has higher priority.
*
* If plain password is present, calculate its NT and LM hashes
* and remove it from the memory.
*/
if (!strlen(cpassword)) {
if (strlen(cpassntlm2)) {
tmp = scanmem(cpassntlm2, 8);
if (!tmp) {
syslog(LOG_ERR, "Invalid PassNTLMv2 hash, terminating\n");
exit(1);
}
auth_memcpy(g_creds, passntlm2, tmp, 16);
free(tmp);
}
if (strlen(cpassnt)) {
tmp = scanmem(cpassnt, 8);
if (!tmp) {
syslog(LOG_ERR, "Invalid PassNT hash, terminating\n");
exit(1);
}
auth_memcpy(g_creds, passnt, tmp, 16);
free(tmp);
}
if (strlen(cpasslm)) {
tmp = scanmem(cpasslm, 8);
if (!tmp) {
syslog(LOG_ERR, "Invalid PassLM hash, terminating\n");
exit(1);
}
auth_memcpy(g_creds, passlm, tmp, 16);
free(tmp);
}
} else {
if (g_creds->hashnt || magic_detect || interactivehash) {
tmp = ntlm_hash_nt_password(cpassword);
auth_memcpy(g_creds, passnt, tmp, 21);
free(tmp);
} if (g_creds->hashlm || magic_detect || interactivehash) {
tmp = ntlm_hash_lm_password(cpassword);
auth_memcpy(g_creds, passlm, tmp, 21);
free(tmp);
} if (g_creds->hashntlm2 || magic_detect || interactivehash) {
tmp = ntlm2_hash_password(cuser, cdomain, cpassword);
auth_memcpy(g_creds, passntlm2, tmp, 16);
free(tmp);
}
memset(cpassword, 0, strlen(cpassword));
}
auth_strcpy(g_creds, user, cuser);
auth_strcpy(g_creds, domain, cdomain);
auth_strcpy(g_creds, workstation, cworkstation);
free(cuser);
free(cdomain);
free(cworkstation);
free(cpassword);
free(cpassntlm2);
free(cpassnt);
free(cpasslm);
free(cauth);
/*
* Try known NTLM auth combinations and print which ones work.
* User can pick the best (most secure) one as his config.
*/
if (magic_detect) {
magic_auth_detect(magic_detect);
goto bailout;
}
if (interactivehash) {
if (g_creds->passlm) {
tmp = printmem(g_creds->passlm, 16, 8);
printf("PassLM %s\n", tmp);
free(tmp);
}
if (g_creds->passnt) {
tmp = printmem(g_creds->passnt, 16, 8);
printf("PassNT %s\n", tmp);
free(tmp);
}
if (g_creds->passntlm2) {
tmp = printmem(g_creds->passntlm2, 16, 8);
printf("PassNTLMv2 %s # Only for user '%s', domain '%s'\n",
tmp, g_creds->user, g_creds->domain);
free(tmp);
}
goto bailout;
}
/*
* If we're going to need a password, check we really have it.
*/
if (!ntlmbasic && (
(g_creds->hashnt && !g_creds->passnt)
|| (g_creds->hashlm && !g_creds->passlm)
|| (g_creds->hashntlm2 && !g_creds->passntlm2))) {
syslog(LOG_ERR, "Parent proxy account password (or required hashes) missing.\n");
myexit(1);
}
/*
* Ok, we are ready to rock. If daemon mode was requested,
* fork and die. The child will not be group leader anymore
* and can thus create a new session for itself and detach
* from the controlling terminal.
*/
if (asdaemon) {
if (debug)
printf("Forking into background as requested.\n");
i = fork();
if (i == -1) {
perror("Fork into background failed"); /* fork failed */
myexit(1);
} else if (i)
myexit(0); /* parent */
setsid();
umask(0);
w = chdir("/");
i = open("/dev/null", O_RDWR);
if (i >= 0) {
dup2(i, 0);
dup2(i, 1);
dup2(i, 2);
if (i > 2)
close(i);
}
}
/*
* Reinit syslog logging to include our PID, after forking
* it is going to be OK
*/
if (asdaemon) {
openlog("cntlm", LOG_CONS | LOG_PID, LOG_DAEMON);
syslog(LOG_INFO, "Daemon ready");
} else {
openlog("cntlm", LOG_CONS | LOG_PID | LOG_PERROR, LOG_DAEMON);
syslog(LOG_INFO, "Cntlm ready, staying in the foreground");
}
/*
* Check and change UID.
*/
if (strlen(cuid)) {
if (getuid() && geteuid()) {
syslog(LOG_WARNING, "No root privileges; keeping identity %d:%d\n", getuid(), getgid());
} else {
if (isdigit(cuid[0])) {
nuid = atoi(cuid);
ngid = nuid;
if (nuid <= 0) {
syslog(LOG_ERR, "Numerical uid parameter invalid\n");
myexit(1);
}
} else {
pw = getpwnam(cuid);
if (!pw || !pw->pw_uid) {
syslog(LOG_ERR, "Username %s in -U is invalid\n", cuid);
myexit(1);
}
nuid = pw->pw_uid;
ngid = pw->pw_gid;
}
setgid(ngid);
i = setuid(nuid);
syslog(LOG_INFO, "Changing uid:gid to %d:%d - %s\n", nuid, ngid, strerror(errno));
if (i) {
syslog(LOG_ERR, "Terminating\n");
myexit(1);
}
}
}
/*
* PID file requested? Try to create one (it must not exist).
* If we fail, exit with error.
*/
if (strlen(cpidfile)) {
umask(0);
cd = open(cpidfile, O_WRONLY | O_CREAT | O_TRUNC, 0644);
if (cd < 0) {
syslog(LOG_ERR, "Error creating a new PID file\n");
myexit(1);
}
tmp = new(50);
snprintf(tmp, 50, "%d\n", getpid());
w = write(cd, tmp, strlen(tmp));
free(tmp);
close(cd);
}
/*
* Change the handler for signals recognized as clean shutdown.
* When the handler is called (termination request), it signals
* this news by adding 1 to the global quit variable.
*/
signal(SIGPIPE, SIG_IGN);
signal(SIGINT, &sighandler);
signal(SIGTERM, &sighandler);
signal(SIGHUP, &sighandler);
/*
* Initialize the random number generator
*/
srandom(time(NULL));
/*
* This loop iterates over every connection request on any of
* the listening ports. We keep the number of created threads.
*
* We also check the "finished threads" list, threads_list, here and
* free the memory of all inactive threads. Then, we update the
* number of finished threads.
*
* The loop ends, when we were "killed" and all threads created
* are finished, OR if we were killed more than once. This way,
* we have a "clean" shutdown (wait for all connections to finish
* after the first kill) and a "forced" one (user insists and
* killed us twice).
*/
while (quit == 0 || (tc != tj && quit < 2)) {
struct thread_arg_s *data;
struct sockaddr_in caddr;
struct timeval tv;
socklen_t clen;
fd_set set;
plist_t t;
int tid = 0;
FD_ZERO(&set);
/*
* Watch for proxy ports.
*/
t = proxyd_list;
while (t) {
FD_SET(t->key, &set);
t = t->next;
}
/*
* Watch for SOCKS5 ports.
*/
t = socksd_list;
while (t) {
FD_SET(t->key, &set);
t = t->next;
}
/*
* Watch for tunneled ports.
*/
t = tunneld_list;
while (t) {
FD_SET(t->key, &set);
t = t->next;
}
tv.tv_sec = 1;
tv.tv_usec = 0;
/*
* Wait here for data (connection request) on any of the listening
* sockets. When ready, establish the connection. For the main
* port, a new proxy_thread() thread is spawned to service the HTTP
* request. For tunneled ports, tunnel_thread() thread is created
* and for SOCKS port, socks5_thread() is created.
*
* All threads are defined in forward.c, except for local proxy_thread()
* which routes the request as forwarded or direct, depending on the
* URL host name and NoProxy settings.
*/
cd = select(FD_SETSIZE, &set, NULL, NULL, &tv);
if (cd > 0) {
for (i = 0; i < FD_SETSIZE; ++i) {
if (!FD_ISSET(i, &set))
continue;
clen = sizeof(caddr);
cd = accept(i, (struct sockaddr *)&caddr, (socklen_t *)&clen);
if (cd < 0) {
syslog(LOG_ERR, "Serious error during accept: %s\n", strerror(errno));
continue;
}
/*
* Check main access control list.
*/
if (acl_check(rules, caddr.sin_addr) != ACL_ALLOW) {
syslog(LOG_WARNING, "Connection denied for %s:%d\n",
inet_ntoa(caddr.sin_addr), ntohs(caddr.sin_port));
tmp = gen_denied_page(inet_ntoa(caddr.sin_addr));
w = write(cd, tmp, strlen(tmp));
free(tmp);
close(cd);
continue;
}
/*
* Log peer IP if it's not localhost
*
* if (debug || (gateway && caddr.sin_addr.s_addr != htonl(INADDR_LOOPBACK)))
* syslog(LOG_INFO, "Connection accepted from %s:%d\n",
* inet_ntoa(caddr.sin_addr), ntohs(caddr.sin_port));
*/
pthread_attr_init(&pattr);
pthread_attr_setstacksize(&pattr, STACK_SIZE);
#ifndef __CYGWIN__
pthread_attr_setguardsize(&pattr, 256);
#endif
if (plist_in(proxyd_list, i)) {
data = (struct thread_arg_s *)new(sizeof(struct thread_arg_s));
data->fd = cd;
data->addr = caddr;
if (!serialize)
tid = pthread_create(&pthr, &pattr, proxy_thread, (void *)data);
else
proxy_thread((void *)data);
} else if (plist_in(socksd_list, i)) {
data = (struct thread_arg_s *)new(sizeof(struct thread_arg_s));
data->fd = cd;
data->addr = caddr;
tid = pthread_create(&pthr, &pattr, socks5_thread, (void *)data);
} else {
data = (struct thread_arg_s *)new(sizeof(struct thread_arg_s));
data->fd = cd;
data->addr = caddr;
data->target = plist_get(tunneld_list, i);
tid = pthread_create(&pthr, &pattr, tunnel_thread, (void *)data);
}
pthread_attr_destroy(&pattr);
if (tid)
syslog(LOG_ERR, "Serious error during pthread_create: %d\n", tid);
else
tc++;
}
} else if (cd < 0 && !quit)
syslog(LOG_ERR, "Serious error during select: %s\n", strerror(errno));
if (threads_list) {
pthread_mutex_lock(&threads_mtx);
t = threads_list;
while (t) {
plist_t tmp = t->next;
tid = pthread_join((pthread_t)t->key, (void *)&i);
if (!tid) {
tj++;
if (debug)
printf("Joining thread %lu; rc: %d\n", t->key, i);
} else
syslog(LOG_ERR, "Serious error during pthread_join: %d\n", tid);
free(t);
t = tmp;
}
threads_list = NULL;
pthread_mutex_unlock(&threads_mtx);
}
}
bailout:
if (strlen(cpidfile))
unlink(cpidfile);
syslog(LOG_INFO, "Terminating with %d active threads\n", tc - tj);
pthread_mutex_lock(&connection_mtx);
plist_free(connection_list);
pthread_mutex_unlock(&connection_mtx);
hlist_free(header_list);
plist_free(scanner_agent_list);
plist_free(noproxy_list);
plist_free(tunneld_list);
plist_free(proxyd_list);
plist_free(socksd_list);
plist_free(rules);
free(cuid);
free(cpidfile);
free(magic_detect);
free(g_creds);
plist_free(parent_list);
exit(0);
}
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