1 #if defined(NO_BUFFER) || defined(NO_IP) || defined(NO_OPENSSL)
2 #error "Badness, NO_BUFFER, NO_IP or NO_OPENSSL is defined, turn them *off*"
5 /* Include our bits'n'pieces */
9 /********************************************/
10 /* Our local types that specify our "world" */
11 /********************************************/
13 /* These represent running "tunnels". Eg. if you wanted to do SSL in a
14 * "message-passing" scanario, the "int" file-descriptors might be replaced by
15 * thread or process IDs, and the "select" code might be replaced by message
16 * handling code. Whatever. */
17 typedef struct _tunala_item_t {
18 /* The underlying SSL state machine. This is a data-only processing unit
19 * and we communicate with it by talking to its four "buffers". */
21 /* The file-descriptors for the "dirty" (encrypted) side of the SSL
22 * setup. In actuality, this is typically a socket and both values are
24 int dirty_read, dirty_send;
25 /* The file-descriptors for the "clean" (unencrypted) side of the SSL
26 * setup. These could be stdin/stdout, a socket (both values the same),
27 * or whatever you like. */
28 int clean_read, clean_send;
31 /* This structure is used as the data for running the main loop. Namely, in a
32 * network format such as this, it is stuff for select() - but as pointed out,
33 * when moving the real-world to somewhere else, this might be replaced by
34 * something entirely different. It's basically the stuff that controls when
35 * it's time to do some "work". */
36 typedef struct _select_sets_t {
37 int max; /* As required as the first argument to select() */
38 fd_set reads, sends, excepts; /* As passed to select() */
40 typedef struct _tunala_selector_t {
41 select_sets_t last_selected; /* Results of the last select() */
42 select_sets_t next_select; /* What we'll next select on */
45 /* This structure is *everything*. We do it to avoid the use of globals so that,
46 * for example, it would be easier to shift things around between async-IO,
47 * thread-based, or multi-fork()ed (or combinations thereof). */
48 typedef struct _tunala_world_t {
49 /* The file-descriptor we "listen" on for new connections */
51 /* The array of tunnels */
52 tunala_item_t *tunnels;
53 /* the number of tunnels in use and allocated, respectively */
54 unsigned int tunnels_used, tunnels_size;
55 /* Our outside "loop" context stuff */
56 tunala_selector_t selector;
57 /* Our SSL_CTX, which is configured as the SSL client or server and has
58 * the various cert-settings and callbacks configured. */
60 /* Simple flag with complex logic :-) Indicates whether we're an SSL
61 * server or an SSL client. */
65 /*****************************/
66 /* Internal static functions */
67 /*****************************/
69 static SSL_CTX *initialise_ssl_ctx(int server_mode, const char *engine_id,
70 const char *CAfile, const char *cert, const char *key);
71 static void selector_init(tunala_selector_t *selector);
72 static void selector_add_listener(tunala_selector_t *selector, int fd);
73 static void selector_add_tunala(tunala_selector_t *selector, tunala_item_t *t);
74 static int selector_select(tunala_selector_t *selector);
75 /* This returns -1 for error, 0 for no new connections, or 1 for success, in
76 * which case *newfd is populated. */
77 static int selector_get_listener(tunala_selector_t *selector, int fd, int *newfd);
78 static int tunala_world_new_item(tunala_world_t *world, int fd,
79 const unsigned char *ip, unsigned short port);
80 static void tunala_world_del_item(tunala_world_t *world, unsigned int idx);
81 static int tunala_item_io(tunala_selector_t *selector, tunala_item_t *item);
83 /*********************************************/
84 /* MAIN FUNCTION (and its utility functions) */
85 /*********************************************/
87 /* For now, hard-coded as follows;
88 * (a) We're like "tunala -listen 127.0.0.1:9001 -proxy 127.0.0.1:9002"
89 * (b) We max out at 50 simultaneous tunnels, listening will stop while we have
90 * that many tunnels operating and will recommence as/when tunnels close.
91 * (c) We are an SSL client proxy
92 * (d) We use the "openssl" ENGINE
93 * (e) We use the CA cert file "cacert.pem"
96 static const char *def_proxyhost = "127.0.0.1:443";
97 static const char *def_listenhost = "127.0.0.1:8080";
98 static int def_max_tunnels = 50;
99 static const char *def_cacert = NULL;
100 static const char *def_cert = NULL;
101 static const char *def_key = NULL;
102 static const char *def_engine_id = NULL;
103 static int def_server_mode = 0;
105 static const char *helpstring =
106 "\n'Tunala' (A tunneler with a New Zealand accent)\n"
107 "Usage: tunala [options], where options are from;\n"
108 " -listen [host:]<port> (default = 127.0.0.1:8080)\n"
109 " -proxy <host>:<port> (default = 127.0.0.1:443)\n"
110 " -maxtunnels <num> (default = 50)\n"
111 " -cacert <path|NULL> (default = NULL)\n"
112 " -cert <path|NULL> (default = NULL)\n"
113 " -key <path|NULL> (default = whatever '-cert' is)\n"
114 " -engine <id|NULL> (default = NULL)\n"
115 " -server <0|1> (default = 0, ie. an SSL client)\n"
116 " -<h|help|?> (displays this help screen)\n"
117 "NB: It is recommended to specify a cert+key when operating as an\n"
118 "SSL server. If you only specify '-cert', the same file must\n"
119 "contain a matching private key.\n";
121 static int usage(const char *errstr, int isunknownarg)
124 fprintf(stderr, "Error: unknown argument '%s'\n", errstr);
126 fprintf(stderr, "Error: %s\n", errstr);
127 fprintf(stderr, "%s\n", helpstring);
131 static int err_str0(const char *str0)
133 fprintf(stderr, str0);
134 fprintf(stderr, "\n");
138 static int err_str1(const char *str0, const char *str1)
140 fprintf(stderr, str0, str1);
141 fprintf(stderr, "\n");
145 static int parse_max_tunnels(const char *s, unsigned int *maxtunnels)
149 l = strtoul(s, &temp, 10);
150 if((temp == s) || (*temp != '\0') || (l < 1) || (l > 1024)) {
151 fprintf(stderr, "Error, '%s' is an invalid value for "
155 *maxtunnels = (unsigned int)l;
159 static int parse_server_mode(const char *s, int *servermode)
163 l = strtoul(s, &temp, 10);
164 if((temp == s) || (*temp != '\0') || (l > 1)) {
165 fprintf(stderr, "Error, '%s' is an invalid value for the "
169 *servermode = (int)l;
173 int main(int argc, char *argv[])
177 tunala_world_t world;
178 tunala_item_t *t_item;
179 unsigned char *proxy_ip;
180 unsigned short proxy_port;
182 const char *proxyhost = def_proxyhost;
183 const char *listenhost = def_listenhost;
184 unsigned int max_tunnels = def_max_tunnels;
185 const char *cacert = def_cacert;
186 const char *cert = def_cert;
187 const char *key = def_key;
188 const char *engine_id = def_engine_id;
189 int server_mode = def_server_mode;
191 /* Parse command-line arguments */
195 if(strcmp(*argv, "-listen") == 0) {
197 return usage("-listen requires an argument", 0);
201 } else if(strcmp(*argv, "-proxy") == 0) {
203 return usage("-proxy requires an argument", 0);
207 } else if(strcmp(*argv, "-maxtunnels") == 0) {
209 return usage("-maxtunnels requires an argument", 0);
211 if(!parse_max_tunnels(*argv, &max_tunnels))
214 } else if(strcmp(*argv, "-cacert") == 0) {
216 return usage("-cacert requires an argument", 0);
218 if(strcmp(*argv, "NULL") == 0)
223 } else if(strcmp(*argv, "-cert") == 0) {
225 return usage("-cert requires an argument", 0);
227 if(strcmp(*argv, "NULL") == 0)
232 } else if(strcmp(*argv, "-key") == 0) {
234 return usage("-key requires an argument", 0);
236 if(strcmp(*argv, "NULL") == 0)
241 } else if(strcmp(*argv, "-engine") == 0) {
243 return usage("-engine requires an argument", 0);
247 } else if(strcmp(*argv, "-server") == 0) {
249 return usage("-server requires an argument", 0);
251 if(!parse_server_mode(*argv, &server_mode))
254 } else if((strcmp(*argv, "-h") == 0) ||
255 (strcmp(*argv, "-help") == 0) ||
256 (strcmp(*argv, "-?") == 0)) {
257 fprintf(stderr, "%s\n", helpstring);
260 return usage(*argv, 1);
263 /* Initialise network stuff */
265 return err_str0("ip_initialise failed");
266 err_str0("ip_initialise succeeded");
267 /* Create the SSL_CTX */
268 if((world.ssl_ctx = initialise_ssl_ctx(server_mode, engine_id,
269 cacert, cert, key)) == NULL)
270 return err_str1("initialise_ssl_ctx(engine_id=%s) failed",
271 (engine_id == NULL) ? "NULL" : engine_id);
272 err_str1("initialise_ssl_ctx(engine_id=%s) succeeded",
273 (engine_id == NULL) ? "NULL" : engine_id);
274 /* Create the listener */
275 if((world.listen_fd = ip_create_listener(listenhost)) == -1)
276 return err_str1("ip_create_listener(%s) failed", listenhost);
277 err_str1("ip_create_listener(%s) succeeded", listenhost);
278 if(!ip_parse_address(proxyhost, &proxy_ip, &proxy_port, 0))
279 return err_str1("ip_parse_address(%s) failed", proxyhost);
280 err_str1("ip_parse_address(%s) succeeded", proxyhost);
281 fprintf(stderr, "Info - proxying to %d.%d.%d.%d:%d\n",
282 (int)proxy_ip[0], (int)proxy_ip[1],
283 (int)proxy_ip[2], (int)proxy_ip[3], (int)proxy_port);
284 fprintf(stderr, "Info - set maxtunnels to %d\n", (int)max_tunnels);
285 fprintf(stderr, "Info - set to operate as an SSL %s\n",
286 (server_mode ? "server" : "client"));
287 /* Initialise the rest of the stuff */
288 world.tunnels_used = world.tunnels_size = 0;
289 world.tunnels = NULL;
290 world.server_mode = server_mode;
291 selector_init(&world.selector);
293 /* We're ready to loop */
295 /* Should we listen for *new* tunnels? */
296 if(world.tunnels_used < max_tunnels)
297 selector_add_listener(&world.selector, world.listen_fd);
298 /* We should add in our existing tunnels */
299 for(loop = 0; loop < world.tunnels_used; loop++)
300 selector_add_tunala(&world.selector, world.tunnels + loop);
301 /* Now do the select */
302 switch(selector_select(&world.selector)) {
304 fprintf(stderr, "selector_select returned a badness error.\n");
307 fprintf(stderr, "Warn, selector_select return 0 - signal??\n");
312 /* Accept new connection if we should and can */
313 if((world.tunnels_used < max_tunnels) && (selector_get_listener(
314 &world.selector, world.listen_fd,
316 /* We have a new connection */
317 if(!tunala_world_new_item(&world, newfd,
318 proxy_ip, proxy_port)) {
319 fprintf(stderr, "tunala_world_new_item failed\n");
322 fprintf(stderr, "Info, new tunnel opened, now up to %d\n",
325 /* Give each tunnel its moment, note the while loop is because it makes
326 * the logic easier than with "for" to deal with an array that may shift
327 * because of deletes. */
329 t_item = world.tunnels;
330 while(loop < world.tunnels_used) {
331 if(!tunala_item_io(&world.selector, t_item)) {
332 /* We're closing whether for reasons of an error or a
333 * natural close. Don't increment loop or t_item because
334 * the next item is moving to us! */
335 tunala_world_del_item(&world, loop);
336 fprintf(stderr, "Info, tunnel closed, down to %d\n",
340 /* Move to the next item */
346 /* Should never get here */
355 static SSL_CTX *initialise_ssl_ctx(int server_mode, const char *engine_id,
356 const char *CAfile, const char *cert, const char *key)
358 SSL_CTX *ctx, *ret = NULL;
363 EVP_PKEY *pkey = NULL;
365 OpenSSL_add_ssl_algorithms();
366 SSL_load_error_strings();
368 meth = (server_mode ? SSLv23_server_method() : SSLv23_client_method());
372 if((e = ENGINE_by_id(engine_id)) == NULL) {
373 fprintf(stderr, "Error obtaining '%s' engine, openssl "
374 "errors follow\n", engine_id);
377 if(!ENGINE_set_default(e, ENGINE_METHOD_ALL)) {
378 fprintf(stderr, "Error assigning '%s' engine, openssl "
379 "errors follow\n", engine_id);
384 if((ctx = SSL_CTX_new(meth)) == NULL)
388 if(!X509_STORE_load_locations(SSL_CTX_get_cert_store(ctx),
390 fprintf(stderr, "Error loading CA cert(s) in '%s'\n",
394 fprintf(stderr, "Info, operating with CA cert(s) in '%s'\n",
397 fprintf(stderr, "Info, operating without a CA cert(-list)\n");
398 if(!SSL_CTX_set_default_verify_paths(ctx)) {
399 fprintf(stderr, "Error setting default verify paths\n");
404 if((fp = fopen(cert, "r")) == NULL) {
405 fprintf(stderr, "Error opening cert file '%s'\n", cert);
408 if(!PEM_read_X509(fp, &x509, NULL, NULL)) {
409 fprintf(stderr, "Error reading PEM cert from '%s'\n",
413 if(!SSL_CTX_use_certificate(ctx, x509)) {
414 fprintf(stderr, "Error, cert in '%s' can not be used\n",
418 fprintf(stderr, "Info, operating with cert in '%s'\n", cert);
421 /* If a cert was given without matching key, we assume the same
422 * file contains the required key. */
427 fprintf(stderr, "Error, can't specify a key without a "
428 "corresponding certificate\n");
433 if((fp = fopen(key, "r")) == NULL) {
434 fprintf(stderr, "Error opening key file '%s'\n", key);
437 if(!PEM_read_PrivateKey(fp, &pkey, NULL, NULL)) {
438 fprintf(stderr, "Error reading PEM key from '%s'\n",
442 if(!SSL_CTX_use_PrivateKey(ctx, pkey)) {
443 fprintf(stderr, "Error, key in '%s' can not be used\n",
447 fprintf(stderr, "Info, operating with key in '%s'\n", key);
449 fprintf(stderr, "Info, operating without a cert or key\n");
455 ERR_print_errors_fp(stderr);
472 static void selector_sets_init(select_sets_t *s)
477 FD_ZERO(&s->excepts);
479 static void selector_init(tunala_selector_t *selector)
481 selector_sets_init(&selector->last_selected);
482 selector_sets_init(&selector->next_select);
485 #define SEL_EXCEPTS 0x00
486 #define SEL_READS 0x01
487 #define SEL_SENDS 0x02
488 static void selector_add_raw_fd(tunala_selector_t *s, int fd, int flags)
490 FD_SET(fd, &s->next_select.excepts);
491 if(flags & SEL_READS)
492 FD_SET(fd, &s->next_select.reads);
493 if(flags & SEL_SENDS)
494 FD_SET(fd, &s->next_select.sends);
496 if(s->next_select.max < (fd + 1))
497 s->next_select.max = fd + 1;
500 static void selector_add_listener(tunala_selector_t *selector, int fd)
502 selector_add_raw_fd(selector, fd, SEL_READS);
505 static void selector_add_tunala(tunala_selector_t *s, tunala_item_t *t)
507 /* Set clean read if sm.clean_in is not full */
508 if(t->clean_read != -1) {
509 selector_add_raw_fd(s, t->clean_read,
510 (buffer_full(state_machine_get_buffer(&t->sm,
511 SM_CLEAN_IN)) ? SEL_EXCEPTS : SEL_READS));
513 /* Set clean send if sm.clean_out is not empty */
514 if(t->clean_send != -1) {
515 selector_add_raw_fd(s, t->clean_send,
516 (buffer_empty(state_machine_get_buffer(&t->sm,
517 SM_CLEAN_OUT)) ? SEL_EXCEPTS : SEL_SENDS));
519 /* Set dirty read if sm.dirty_in is not full */
520 if(t->dirty_read != -1) {
521 selector_add_raw_fd(s, t->dirty_read,
522 (buffer_full(state_machine_get_buffer(&t->sm,
523 SM_DIRTY_IN)) ? SEL_EXCEPTS : SEL_READS));
525 /* Set dirty send if sm.dirty_out is not empty */
526 if(t->dirty_send != -1) {
527 selector_add_raw_fd(s, t->dirty_send,
528 (buffer_empty(state_machine_get_buffer(&t->sm,
529 SM_DIRTY_OUT)) ? SEL_EXCEPTS : SEL_SENDS));
533 static int selector_select(tunala_selector_t *selector)
535 memcpy(&selector->last_selected, &selector->next_select,
536 sizeof(select_sets_t));
537 selector_sets_init(&selector->next_select);
538 return select(selector->last_selected.max,
539 &selector->last_selected.reads,
540 &selector->last_selected.sends,
541 &selector->last_selected.excepts, NULL);
544 /* This returns -1 for error, 0 for no new connections, or 1 for success, in
545 * which case *newfd is populated. */
546 static int selector_get_listener(tunala_selector_t *selector, int fd, int *newfd)
548 if(FD_ISSET(fd, &selector->last_selected.excepts))
550 if(!FD_ISSET(fd, &selector->last_selected.reads))
552 if((*newfd = ip_accept_connection(fd)) == -1)
557 /************************/
558 /* "Tunala" world stuff */
559 /************************/
561 static int tunala_world_make_room(tunala_world_t *world)
563 unsigned int newsize;
564 tunala_item_t *newarray;
566 if(world->tunnels_used < world->tunnels_size)
568 newsize = (world->tunnels_size == 0 ? 16 :
569 ((world->tunnels_size * 3) / 2));
570 if((newarray = malloc(newsize * sizeof(tunala_item_t))) == NULL)
572 memset(newarray, 0, newsize * sizeof(tunala_item_t));
573 if(world->tunnels_used > 0)
574 memcpy(newarray, world->tunnels,
575 world->tunnels_used * sizeof(tunala_item_t));
576 if(world->tunnels_size > 0)
577 free(world->tunnels);
579 world->tunnels = newarray;
580 world->tunnels_size = newsize;
584 static int tunala_world_new_item(tunala_world_t *world, int fd,
585 const unsigned char *ip, unsigned short port)
590 if(!tunala_world_make_room(world))
592 item = world->tunnels + (world->tunnels_used++);
593 state_machine_init(&item->sm);
594 item->clean_read = item->clean_send =
595 item->dirty_read = item->dirty_send = -1;
596 if((newfd = ip_create_connection_split(ip, port)) == -1)
598 /* Which way round? If we're a server, "fd" is the dirty side and the
599 * connection we open is the clean one. For a client, it's the other way
601 if(world->server_mode) {
602 item->dirty_read = item->dirty_send = fd;
603 item->clean_read = item->clean_send = newfd;
605 item->clean_read = item->clean_send = fd;
606 item->dirty_read = item->dirty_send = newfd;
608 state_machine_set_SSL(&item->sm, SSL_new(world->ssl_ctx),
612 state_machine_close(&item->sm);
617 static void tunala_world_del_item(tunala_world_t *world, unsigned int idx)
619 tunala_item_t *item = world->tunnels + idx;
620 if(item->clean_read != -1)
621 close(item->clean_read);
622 if(item->clean_send != item->clean_read)
623 close(item->clean_send);
624 item->clean_read = item->clean_send = -1;
625 if(item->dirty_read != -1)
626 close(item->dirty_read);
627 if(item->dirty_send != item->dirty_read)
628 close(item->dirty_send);
629 item->dirty_read = item->dirty_send = -1;
630 state_machine_close(&item->sm);
631 /* OK, now we fix the item array */
632 if(idx + 1 < world->tunnels_used)
633 /* We need to scroll entries to the left */
634 memmove(world->tunnels + idx,
635 world->tunnels + (idx + 1),
636 (world->tunnels_used - (idx + 1)) *
637 sizeof(tunala_item_t));
638 world->tunnels_used--;
641 static int tunala_item_io(tunala_selector_t *selector, tunala_item_t *item)
643 int c_r, c_s, d_r, d_s; /* Four boolean flags */
645 /* Take ourselves out of the gene-pool if there was an except */
646 if((item->clean_read != -1) && FD_ISSET(item->clean_read,
647 &selector->last_selected.excepts))
649 if((item->clean_send != -1) && FD_ISSET(item->clean_send,
650 &selector->last_selected.excepts))
652 if((item->dirty_read != -1) && FD_ISSET(item->dirty_read,
653 &selector->last_selected.excepts))
655 if((item->dirty_send != -1) && FD_ISSET(item->dirty_send,
656 &selector->last_selected.excepts))
658 /* Grab our 4 IO flags */
659 c_r = c_s = d_r = d_s = 0;
660 if(item->clean_read != -1)
661 c_r = FD_ISSET(item->clean_read, &selector->last_selected.reads);
662 if(item->clean_send != -1)
663 c_s = FD_ISSET(item->clean_send, &selector->last_selected.sends);
664 if(item->dirty_read != -1)
665 d_r = FD_ISSET(item->dirty_read, &selector->last_selected.reads);
666 if(item->dirty_send != -1)
667 d_s = FD_ISSET(item->dirty_send, &selector->last_selected.sends);
668 /* If no IO has happened for us, skip needless data looping */
669 if(!c_r && !c_s && !d_r && !d_s)
672 c_r = (buffer_from_fd(state_machine_get_buffer(&item->sm,
673 SM_CLEAN_IN), item->clean_read) <= 0);
675 c_s = (buffer_to_fd(state_machine_get_buffer(&item->sm,
676 SM_CLEAN_OUT), item->clean_send) <= 0);
678 d_r = (buffer_from_fd(state_machine_get_buffer(&item->sm,
679 SM_DIRTY_IN), item->dirty_read) <= 0);
681 d_s = (buffer_to_fd(state_machine_get_buffer(&item->sm,
682 SM_DIRTY_OUT), item->dirty_send) <= 0);
683 /* If any of the flags is non-zero, that means they need closing */
685 close(item->clean_read);
686 if(item->clean_send == item->clean_read)
687 item->clean_send = -1;
688 item->clean_read = -1;
691 close(item->clean_send);
692 if(item->clean_send == item->clean_read)
693 item->clean_read = -1;
694 item->clean_send = -1;
697 close(item->dirty_read);
698 if(item->dirty_send == item->dirty_read)
699 item->dirty_send = -1;
700 item->dirty_read = -1;
703 close(item->dirty_send);
704 if(item->dirty_send == item->dirty_read)
705 item->dirty_read = -1;
706 item->dirty_send = -1;
708 /* This function name is attributed to the term donated by David
709 * Schwartz on openssl-dev, message-ID:
710 * <NCBBLIEPOCNJOAEKBEAKEEDGLIAA.davids@webmaster.com>. :-) */
711 if(!state_machine_churn(&item->sm))
712 /* If the SSL closes, it will also zero-out the _in buffers
713 * and will in future process just outgoing data. As and
714 * when the outgoing data has gone, it will return zero
715 * here to tell us to bail out. */
717 /* Otherwise, we return zero if both sides are dead. */
718 if(((item->clean_read == -1) || (item->clean_send == -1)) &&
719 ((item->dirty_read == -1) || (item->dirty_send == -1)))
721 /* If only one side closed, notify the SSL of this so it can take
722 * appropriate action. */
723 if((item->clean_read == -1) || (item->clean_send == -1)) {
724 if(!state_machine_close_clean(&item->sm))
727 if((item->dirty_read == -1) || (item->dirty_send == -1)) {
728 if(state_machine_close_dirty(&item->sm))