e918cba2ce8aa4c1f89a53beab8ed953bb702d53
[openssl.git] / demos / tunala / tunala.c
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*"
3 #endif
4
5 /* Include our bits'n'pieces */
6 #include "tunala.h"
7
8
9 /********************************************/
10 /* Our local types that specify our "world" */
11 /********************************************/
12
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". */
20         state_machine_t sm;
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
23          * identical. */
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;
29 } tunala_item_t;
30
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() */
39 } select_sets_t;
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 */
43 } tunala_selector_t;
44
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 */
50         int listen_fd;
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. */
59         SSL_CTX *ssl_ctx;
60         /* Simple flag with complex logic :-) Indicates whether we're an SSL
61          * server or an SSL client. */
62         int server_mode;
63 } tunala_world_t;
64
65 /*****************************/
66 /* Internal static functions */
67 /*****************************/
68
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                 const char *dcert, const char *dkey, const char *cipher_list,
72                 const char *dh_file, const char *dh_special, int tmp_rsa,
73                 int ctx_options, int out_state, int out_verify, int verify_mode,
74                 unsigned int verify_depth);
75 static void selector_init(tunala_selector_t *selector);
76 static void selector_add_listener(tunala_selector_t *selector, int fd);
77 static void selector_add_tunala(tunala_selector_t *selector, tunala_item_t *t);
78 static int selector_select(tunala_selector_t *selector);
79 /* This returns -1 for error, 0 for no new connections, or 1 for success, in
80  * which case *newfd is populated. */
81 static int selector_get_listener(tunala_selector_t *selector, int fd, int *newfd);
82 static int tunala_world_new_item(tunala_world_t *world, int fd,
83                 const char *ip, unsigned short port, int flipped);
84 static void tunala_world_del_item(tunala_world_t *world, unsigned int idx);
85 static int tunala_item_io(tunala_selector_t *selector, tunala_item_t *item);
86
87 /*********************************************/
88 /* MAIN FUNCTION (and its utility functions) */
89 /*********************************************/
90
91 static const char *def_proxyhost = "127.0.0.1:443";
92 static const char *def_listenhost = "127.0.0.1:8080";
93 static int def_max_tunnels = 50;
94 static const char *def_cacert = NULL;
95 static const char *def_cert = NULL;
96 static const char *def_key = NULL;
97 static const char *def_dcert = NULL;
98 static const char *def_dkey = NULL;
99 static const char *def_engine_id = NULL;
100 static int def_server_mode = 0;
101 static int def_flipped = 0;
102 static const char *def_cipher_list = NULL;
103 static const char *def_dh_file = NULL;
104 static const char *def_dh_special = NULL;
105 static int def_tmp_rsa = 1;
106 static int def_ctx_options = 0;
107 static int def_verify_mode = 0;
108 static unsigned int def_verify_depth = 10;
109 static int def_out_state = 0;
110 static unsigned int def_out_verify = 0;
111 static int def_out_totals = 0;
112 static int def_out_conns = 0;
113
114 static const char *helpstring =
115 "\n'Tunala' (A tunneler with a New Zealand accent)\n"
116 "Usage: tunala [options], where options are from;\n"
117 " -listen [host:]<port>  (default = 127.0.0.1:8080)\n"
118 " -proxy <host>:<port>   (default = 127.0.0.1:443)\n"
119 " -maxtunnels <num>      (default = 50)\n"
120 " -cacert <path|NULL>    (default = NULL)\n"
121 " -cert <path|NULL>      (default = NULL)\n"
122 " -key <path|NULL>       (default = whatever '-cert' is)\n"
123 " -dcert <path|NULL>     (usually for DSA, default = NULL)\n"
124 " -dkey <path|NULL>      (usually for DSA, default = whatever '-dcert' is)\n"
125 " -engine <id|NULL>      (default = NULL)\n"
126 " -server <0|1>          (default = 0, ie. an SSL client)\n"
127 " -flipped <0|1>         (makes SSL servers be network clients, and vice versa)\n"
128 " -cipher <list>         (specifies cipher list to use)\n"
129 " -dh_file <path>        (a PEM file containing DH parameters to use)\n"
130 " -dh_special <NULL|generate|standard> (see below: def=NULL)\n"
131 " -no_tmp_rsa            (don't generate temporary RSA keys)\n"
132 " -no_ssl2               (disable SSLv2)\n"
133 " -no_ssl3               (disable SSLv3)\n"
134 " -no_tls1               (disable TLSv1)\n"
135 " -v_peer                (verify the peer certificate)\n"
136 " -v_strict              (do not continue if peer doesn't authenticate)\n"
137 " -v_once                (no verification in renegotiates)\n"
138 " -v_depth <num>         (limit certificate chain depth, default = 10)\n"
139 " -out_conns             (prints client connections and disconnections)\n"
140 " -out_state             (prints SSL handshake states)\n"
141 " -out_verify <0|1|2|3>  (prints certificate verification states: def=1)\n"
142 " -out_totals            (prints out byte-totals when a tunnel closes)\n"
143 " -<h|help|?>            (displays this help screen)\n"
144 "Notes:\n"
145 "(1) It is recommended to specify a cert+key when operating as an SSL server.\n"
146 "    If you only specify '-cert', the same file must contain a matching\n"
147 "    private key.\n"
148 "(2) Either dh_file or dh_special can be used to specify where DH parameters\n"
149 "    will be obtained from (or '-dh_special NULL' for the default choice) but\n"
150 "    you cannot specify both. For dh_special, 'generate' will create new DH\n"
151 "    parameters on startup, and 'standard' will use embedded parameters\n"
152 "    instead.\n"
153 "(3) Normally an ssl client connects to an ssl server - so that an 'ssl client\n"
154 "    tunala' listens for 'clean' client connections and proxies ssl, and an\n"
155 "    'ssl server tunala' listens for ssl connections and proxies 'clean'. With\n"
156 "    '-flipped 1', this behaviour is reversed so that an 'ssl server tunala'\n"
157 "    listens for clean client connections and proxies ssl (but participating\n"
158 "    as an ssl *server* in the SSL/TLS protocol), and an 'ssl client tunala'\n"
159 "    listens for ssl connections (participating as an ssl *client* in the\n"
160 "    SSL/TLS protocol) and proxies 'clean' to the end destination. This can\n"
161 "    be useful for allowing network access to 'servers' where only the server\n"
162 "    needs to authenticate the client (ie. the other way is not required).\n"
163 "    Even with client and server authentication, this 'technique' mitigates\n"
164 "    some DoS (denial-of-service) potential as it will be the network client\n"
165 "    having to perform the first private key operation rather than the other\n"
166 "    way round.\n"
167 "(4) The 'technique' used by setting '-flipped 1' is probably compatible with\n"
168 "    absolutely nothing except another complimentary instance of 'tunala'\n"
169 "    running with '-flipped 1'. :-)\n";
170
171 /* Default DH parameters for use with "-dh_special standard" ... stolen striaght
172  * from s_server. */
173 static unsigned char dh512_p[]={
174         0xDA,0x58,0x3C,0x16,0xD9,0x85,0x22,0x89,0xD0,0xE4,0xAF,0x75,
175         0x6F,0x4C,0xCA,0x92,0xDD,0x4B,0xE5,0x33,0xB8,0x04,0xFB,0x0F,
176         0xED,0x94,0xEF,0x9C,0x8A,0x44,0x03,0xED,0x57,0x46,0x50,0xD3,
177         0x69,0x99,0xDB,0x29,0xD7,0x76,0x27,0x6B,0xA2,0xD3,0xD4,0x12,
178         0xE2,0x18,0xF4,0xDD,0x1E,0x08,0x4C,0xF6,0xD8,0x00,0x3E,0x7C,
179         0x47,0x74,0xE8,0x33,
180         };
181 static unsigned char dh512_g[]={
182         0x02,
183         };
184
185 /* And the function that parses the above "standard" parameters, again, straight
186  * out of s_server. */
187 static DH *get_dh512(void)
188         {
189         DH *dh=NULL;
190
191         if ((dh=DH_new()) == NULL) return(NULL);
192         dh->p=BN_bin2bn(dh512_p,sizeof(dh512_p),NULL);
193         dh->g=BN_bin2bn(dh512_g,sizeof(dh512_g),NULL);
194         if ((dh->p == NULL) || (dh->g == NULL))
195                 return(NULL);
196         return(dh);
197         }
198
199 /* Various help/error messages used by main() */
200 static int usage(const char *errstr, int isunknownarg)
201 {
202         if(isunknownarg)
203                 fprintf(stderr, "Error: unknown argument '%s'\n", errstr);
204         else
205                 fprintf(stderr, "Error: %s\n", errstr);
206         fprintf(stderr, "%s\n", helpstring);
207         return 1;
208 }
209
210 static int err_str0(const char *str0)
211 {
212         fprintf(stderr, "%s\n", str0);
213         return 1;
214 }
215
216 static int err_str1(const char *fmt, const char *str1)
217 {
218         fprintf(stderr, fmt, str1);
219         fprintf(stderr, "\n");
220         return 1;
221 }
222
223 static int parse_max_tunnels(const char *s, unsigned int *maxtunnels)
224 {
225         unsigned long l;
226         if(!int_strtoul(s, &l) || (l < 1) || (l > 1024)) {
227                 fprintf(stderr, "Error, '%s' is an invalid value for "
228                                 "maxtunnels\n", s);
229                 return 0;
230         }
231         *maxtunnels = (unsigned int)l;
232         return 1;
233 }
234
235 static int parse_server_mode(const char *s, int *servermode)
236 {
237         unsigned long l;
238         if(!int_strtoul(s, &l) || (l > 1)) {
239                 fprintf(stderr, "Error, '%s' is an invalid value for the "
240                                 "server mode\n", s);
241                 return 0;
242         }
243         *servermode = (int)l;
244         return 1;
245 }
246
247 static int parse_dh_special(const char *s, const char **dh_special)
248 {
249         if((strcmp(s, "NULL") == 0) || (strcmp(s, "generate") == 0) ||
250                         (strcmp(s, "standard") == 0)) {
251                 *dh_special = s;
252                 return 1;
253         }
254         fprintf(stderr, "Error, '%s' is an invalid value for 'dh_special'\n", s);
255         return 0;
256 }
257
258 static int parse_verify_level(const char *s, unsigned int *verify_level)
259 {
260         unsigned long l;
261         if(!int_strtoul(s, &l) || (l > 3)) {
262                 fprintf(stderr, "Error, '%s' is an invalid value for "
263                                 "out_verify\n", s);
264                 return 0;
265         }
266         *verify_level = (unsigned int)l;
267         return 1;
268 }
269
270 static int parse_verify_depth(const char *s, unsigned int *verify_depth)
271 {
272         unsigned long l;
273         if(!int_strtoul(s, &l) || (l < 1) || (l > 50)) {
274                 fprintf(stderr, "Error, '%s' is an invalid value for "
275                                 "verify_depth\n", s);
276                 return 0;
277         }
278         *verify_depth = (unsigned int)l;
279         return 1;
280 }
281
282 /* Some fprintf format strings used when tunnels close */
283 static const char *io_stats_dirty =
284 "    SSL traffic;   %8lu bytes in, %8lu bytes out\n";
285 static const char *io_stats_clean =
286 "    clear traffic; %8lu bytes in, %8lu bytes out\n";
287
288 int main(int argc, char *argv[])
289 {
290         unsigned int loop;
291         int newfd;
292         tunala_world_t world;
293         tunala_item_t *t_item;
294         const char *proxy_ip;
295         unsigned short proxy_port;
296         /* Overridables */
297         const char *proxyhost = def_proxyhost;
298         const char *listenhost = def_listenhost;
299         unsigned int max_tunnels = def_max_tunnels;
300         const char *cacert = def_cacert;
301         const char *cert = def_cert;
302         const char *key = def_key;
303         const char *dcert = def_dcert;
304         const char *dkey = def_dkey;
305         const char *engine_id = def_engine_id;
306         int server_mode = def_server_mode;
307         int flipped = def_flipped;
308         const char *cipher_list = def_cipher_list;
309         const char *dh_file = def_dh_file;
310         const char *dh_special = def_dh_special;
311         int tmp_rsa = def_tmp_rsa;
312         int ctx_options = def_ctx_options;
313         int verify_mode = def_verify_mode;
314         unsigned int verify_depth = def_verify_depth;
315         int out_state = def_out_state;
316         unsigned int out_verify = def_out_verify;
317         int out_totals = def_out_totals;
318         int out_conns = def_out_conns;
319
320 /* Parse command-line arguments */
321 next_arg:
322         argc--; argv++;
323         if(argc > 0) {
324                 if(strcmp(*argv, "-listen") == 0) {
325                         if(argc < 2)
326                                 return usage("-listen requires an argument", 0);
327                         argc--; argv++;
328                         listenhost = *argv;
329                         goto next_arg;
330                 } else if(strcmp(*argv, "-proxy") == 0) {
331                         if(argc < 2)
332                                 return usage("-proxy requires an argument", 0);
333                         argc--; argv++;
334                         proxyhost = *argv;
335                         goto next_arg;
336                 } else if(strcmp(*argv, "-maxtunnels") == 0) {
337                         if(argc < 2)
338                                 return usage("-maxtunnels requires an argument", 0);
339                         argc--; argv++;
340                         if(!parse_max_tunnels(*argv, &max_tunnels))
341                                 return 1;
342                         goto next_arg;
343                 } else if(strcmp(*argv, "-cacert") == 0) {
344                         if(argc < 2)
345                                 return usage("-cacert requires an argument", 0);
346                         argc--; argv++;
347                         if(strcmp(*argv, "NULL") == 0)
348                                 cacert = NULL;
349                         else
350                                 cacert = *argv;
351                         goto next_arg;
352                 } else if(strcmp(*argv, "-cert") == 0) {
353                         if(argc < 2)
354                                 return usage("-cert requires an argument", 0);
355                         argc--; argv++;
356                         if(strcmp(*argv, "NULL") == 0)
357                                 cert = NULL;
358                         else
359                                 cert = *argv;
360                         goto next_arg;
361                 } else if(strcmp(*argv, "-key") == 0) {
362                         if(argc < 2)
363                                 return usage("-key requires an argument", 0);
364                         argc--; argv++;
365                         if(strcmp(*argv, "NULL") == 0)
366                                 key = NULL;
367                         else
368                                 key = *argv;
369                         goto next_arg;
370                 } else if(strcmp(*argv, "-dcert") == 0) {
371                         if(argc < 2)
372                                 return usage("-dcert requires an argument", 0);
373                         argc--; argv++;
374                         if(strcmp(*argv, "NULL") == 0)
375                                 dcert = NULL;
376                         else
377                                 dcert = *argv;
378                         goto next_arg;
379                 } else if(strcmp(*argv, "-dkey") == 0) {
380                         if(argc < 2)
381                                 return usage("-dkey requires an argument", 0);
382                         argc--; argv++;
383                         if(strcmp(*argv, "NULL") == 0)
384                                 dkey = NULL;
385                         else
386                                 dkey = *argv;
387                         goto next_arg;
388                 } else if(strcmp(*argv, "-engine") == 0) {
389                         if(argc < 2)
390                                 return usage("-engine requires an argument", 0);
391                         argc--; argv++;
392                         engine_id = *argv;
393                         goto next_arg;
394                 } else if(strcmp(*argv, "-server") == 0) {
395                         if(argc < 2)
396                                 return usage("-server requires an argument", 0);
397                         argc--; argv++;
398                         if(!parse_server_mode(*argv, &server_mode))
399                                 return 1;
400                         goto next_arg;
401                 } else if(strcmp(*argv, "-flipped") == 0) {
402                         if(argc < 2)
403                                 return usage("-flipped requires an argument", 0);
404                         argc--; argv++;
405                         if(!parse_server_mode(*argv, &flipped))
406                                 return 1;
407                         goto next_arg;
408                 } else if(strcmp(*argv, "-cipher") == 0) {
409                         if(argc < 2)
410                                 return usage("-cipher requires an argument", 0);
411                         argc--; argv++;
412                         cipher_list = *argv;
413                         goto next_arg;
414                 } else if(strcmp(*argv, "-dh_file") == 0) {
415                         if(argc < 2)
416                                 return usage("-dh_file requires an argument", 0);
417                         if(dh_special)
418                                 return usage("cannot mix -dh_file with "
419                                                 "-dh_special", 0);
420                         argc--; argv++;
421                         dh_file = *argv;
422                         goto next_arg;
423                 } else if(strcmp(*argv, "-dh_special") == 0) {
424                         if(argc < 2)
425                                 return usage("-dh_special requires an argument", 0);
426                         if(dh_file)
427                                 return usage("cannot mix -dh_file with "
428                                                 "-dh_special", 0);
429                         argc--; argv++;
430                         if(!parse_dh_special(*argv, &dh_special))
431                                 return 1;
432                         goto next_arg;
433                 } else if(strcmp(*argv, "-no_tmp_rsa") == 0) {
434                         tmp_rsa = 0;
435                         goto next_arg;
436                 } else if(strcmp(*argv, "-no_ssl2") == 0) {
437                         ctx_options |= SSL_OP_NO_SSLv2;
438                         goto next_arg;
439                 } else if(strcmp(*argv, "-no_ssl3") == 0) {
440                         ctx_options |= SSL_OP_NO_SSLv3;
441                         goto next_arg;
442                 } else if(strcmp(*argv, "-no_tls1") == 0) {
443                         ctx_options |= SSL_OP_NO_TLSv1;
444                         goto next_arg;
445                 } else if(strcmp(*argv, "-v_peer") == 0) {
446                         verify_mode |= SSL_VERIFY_PEER;
447                         goto next_arg;
448                 } else if(strcmp(*argv, "-v_strict") == 0) {
449                         verify_mode |= SSL_VERIFY_FAIL_IF_NO_PEER_CERT;
450                         goto next_arg;
451                 } else if(strcmp(*argv, "-v_once") == 0) {
452                         verify_mode |= SSL_VERIFY_CLIENT_ONCE;
453                         goto next_arg;
454                 } else if(strcmp(*argv, "-v_depth") == 0) {
455                         if(argc < 2)
456                                 return usage("-v_depth requires an argument", 0);
457                         argc--; argv++;
458                         if(!parse_verify_depth(*argv, &verify_depth))
459                                 return 1;
460                         goto next_arg;
461                 } else if(strcmp(*argv, "-out_state") == 0) {
462                         out_state = 1;
463                         goto next_arg;
464                 } else if(strcmp(*argv, "-out_verify") == 0) {
465                         if(argc < 2)
466                                 return usage("-out_verify requires an argument", 0);
467                         argc--; argv++;
468                         if(!parse_verify_level(*argv, &out_verify))
469                                 return 1;
470                         goto next_arg;
471                 } else if(strcmp(*argv, "-out_totals") == 0) {
472                         out_totals = 1;
473                         goto next_arg;
474                 } else if(strcmp(*argv, "-out_conns") == 0) {
475                         out_conns = 1;
476                         goto next_arg;
477                 } else if((strcmp(*argv, "-h") == 0) ||
478                                 (strcmp(*argv, "-help") == 0) ||
479                                 (strcmp(*argv, "-?") == 0)) {
480                         fprintf(stderr, "%s\n", helpstring);
481                         return 0;
482                 } else
483                         return usage(*argv, 1);
484         }
485         /* Run any sanity checks we want here */
486         if(!cert && !dcert && server_mode)
487                 fprintf(stderr, "WARNING: you are running an SSL server without "
488                                 "a certificate - this may not work!\n");
489
490         /* Initialise network stuff */
491         if(!ip_initialise())
492                 return err_str0("ip_initialise failed");
493         /* Create the SSL_CTX */
494         if((world.ssl_ctx = initialise_ssl_ctx(server_mode, engine_id,
495                         cacert, cert, key, dcert, dkey, cipher_list, dh_file,
496                         dh_special, tmp_rsa, ctx_options, out_state, out_verify,
497                         verify_mode, verify_depth)) == NULL)
498                 return err_str1("initialise_ssl_ctx(engine_id=%s) failed",
499                         (engine_id == NULL) ? "NULL" : engine_id);
500         if(engine_id)
501                 fprintf(stderr, "Info, engine '%s' initialised\n", engine_id);
502         /* Create the listener */
503         if((world.listen_fd = ip_create_listener(listenhost)) == -1)
504                 return err_str1("ip_create_listener(%s) failed", listenhost);
505         fprintf(stderr, "Info, listening on '%s'\n", listenhost);
506         if(!ip_parse_address(proxyhost, &proxy_ip, &proxy_port, 0))
507                 return err_str1("ip_parse_address(%s) failed", proxyhost);
508         fprintf(stderr, "Info, proxying to '%s' (%d.%d.%d.%d:%d)\n", proxyhost,
509                         (int)proxy_ip[0], (int)proxy_ip[1],
510                         (int)proxy_ip[2], (int)proxy_ip[3], (int)proxy_port);
511         fprintf(stderr, "Info, set maxtunnels to %d\n", (int)max_tunnels);
512         fprintf(stderr, "Info, set to operate as an SSL %s\n",
513                         (server_mode ? "server" : "client"));
514         /* Initialise the rest of the stuff */
515         world.tunnels_used = world.tunnels_size = 0;
516         world.tunnels = NULL;
517         world.server_mode = server_mode;
518         selector_init(&world.selector);
519
520 /* We're ready to loop */
521 main_loop:
522         /* Should we listen for *new* tunnels? */
523         if(world.tunnels_used < max_tunnels)
524                 selector_add_listener(&world.selector, world.listen_fd);
525         /* We should add in our existing tunnels */
526         for(loop = 0; loop < world.tunnels_used; loop++)
527                 selector_add_tunala(&world.selector, world.tunnels + loop);
528         /* Now do the select */
529         switch(selector_select(&world.selector)) {
530         case -1:
531                 if(errno != EINTR) {
532                         fprintf(stderr, "selector_select returned a "
533                                         "badness error.\n");
534                         goto shouldnt_happen;
535                 }
536                 fprintf(stderr, "Warn, selector interrupted by a signal\n");
537                 goto main_loop;
538         case 0:
539                 fprintf(stderr, "Warn, selector_select returned 0 - signal?""?\n");
540                 goto main_loop;
541         default:
542                 break;
543         }
544         /* Accept new connection if we should and can */
545         if((world.tunnels_used < max_tunnels) && (selector_get_listener(
546                                         &world.selector, world.listen_fd,
547                                         &newfd) == 1)) {
548                 /* We have a new connection */
549                 if(!tunala_world_new_item(&world, newfd, proxy_ip,
550                                                 proxy_port, flipped))
551                         fprintf(stderr, "tunala_world_new_item failed\n");
552                 else if(out_conns)
553                         fprintf(stderr, "Info, new tunnel opened, now up to "
554                                         "%d\n", world.tunnels_used);
555         }
556         /* Give each tunnel its moment, note the while loop is because it makes
557          * the logic easier than with "for" to deal with an array that may shift
558          * because of deletes. */
559         loop = 0;
560         t_item = world.tunnels;
561         while(loop < world.tunnels_used) {
562                 if(!tunala_item_io(&world.selector, t_item)) {
563                         /* We're closing whether for reasons of an error or a
564                          * natural close. Don't increment loop or t_item because
565                          * the next item is moving to us! */
566                         if(!out_totals)
567                                 goto skip_totals;
568                         fprintf(stderr, "Tunnel closing, traffic stats follow\n");
569                         /* Display the encrypted (over the network) stats */
570                         fprintf(stderr, io_stats_dirty,
571                                 buffer_total_in(state_machine_get_buffer(
572                                                 &t_item->sm,SM_DIRTY_IN)),
573                                 buffer_total_out(state_machine_get_buffer(
574                                                 &t_item->sm,SM_DIRTY_OUT)));
575                         /* Display the local (tunnelled) stats. NB: Data we
576                          * *receive* is data sent *out* of the state_machine on
577                          * its 'clean' side. Hence the apparent back-to-front
578                          * OUT/IN mixup here :-) */
579                         fprintf(stderr, io_stats_clean,
580                                 buffer_total_out(state_machine_get_buffer(
581                                                 &t_item->sm,SM_CLEAN_OUT)),
582                                 buffer_total_in(state_machine_get_buffer(
583                                                 &t_item->sm,SM_CLEAN_IN)));
584 skip_totals:
585                         tunala_world_del_item(&world, loop);
586                         if(out_conns)
587                                 fprintf(stderr, "Info, tunnel closed, down to %d\n",
588                                         world.tunnels_used);
589                 }
590                 else {
591                         /* Move to the next item */
592                         loop++;
593                         t_item++;
594                 }
595         }
596         goto main_loop;
597         /* Should never get here */
598 shouldnt_happen:
599         abort();
600         return 1;
601 }
602
603 /****************/
604 /* OpenSSL bits */
605 /****************/
606
607 static int ctx_set_cert(SSL_CTX *ctx, const char *cert, const char *key)
608 {
609         FILE *fp = NULL;
610         X509 *x509 = NULL;
611         EVP_PKEY *pkey = NULL;
612         int toret = 0; /* Assume an error */
613
614         /* cert */
615         if(cert) {
616                 if((fp = fopen(cert, "r")) == NULL) {
617                         fprintf(stderr, "Error opening cert file '%s'\n", cert);
618                         goto err;
619                 }
620                 if(!PEM_read_X509(fp, &x509, NULL, NULL)) {
621                         fprintf(stderr, "Error reading PEM cert from '%s'\n",
622                                         cert);
623                         goto err;
624                 }
625                 if(!SSL_CTX_use_certificate(ctx, x509)) {
626                         fprintf(stderr, "Error, cert in '%s' can not be used\n",
627                                         cert);
628                         goto err;
629                 }
630                 /* Clear the FILE* for reuse in the "key" code */
631                 fclose(fp);
632                 fp = NULL;
633                 fprintf(stderr, "Info, operating with cert in '%s'\n", cert);
634                 /* If a cert was given without matching key, we assume the same
635                  * file contains the required key. */
636                 if(!key)
637                         key = cert;
638         } else {
639                 if(key)
640                         fprintf(stderr, "Error, can't specify a key without a "
641                                         "corresponding certificate\n");
642                 else
643                         fprintf(stderr, "Error, ctx_set_cert called with "
644                                         "NULLs!\n");
645                 goto err;
646         }
647         /* key */
648         if(key) {
649                 if((fp = fopen(key, "r")) == NULL) {
650                         fprintf(stderr, "Error opening key file '%s'\n", key);
651                         goto err;
652                 }
653                 if(!PEM_read_PrivateKey(fp, &pkey, NULL, NULL)) {
654                         fprintf(stderr, "Error reading PEM key from '%s'\n",
655                                         key);
656                         goto err;
657                 }
658                 if(!SSL_CTX_use_PrivateKey(ctx, pkey)) {
659                         fprintf(stderr, "Error, key in '%s' can not be used\n",
660                                         key);
661                         goto err;
662                 }
663                 fprintf(stderr, "Info, operating with key in '%s'\n", key);
664         } else
665                 fprintf(stderr, "Info, operating without a cert or key\n");
666         /* Success */
667         toret = 1; err:
668         if(x509)
669                 X509_free(x509);
670         if(pkey)
671                 EVP_PKEY_free(pkey);
672         if(fp)
673                 fclose(fp);
674         return toret;
675 }
676
677 static int ctx_set_dh(SSL_CTX *ctx, const char *dh_file, const char *dh_special)
678 {
679         DH *dh = NULL;
680         FILE *fp = NULL;
681
682         if(dh_special) {
683                 if(strcmp(dh_special, "NULL") == 0)
684                         return 1;
685                 if(strcmp(dh_special, "standard") == 0) {
686                         if((dh = get_dh512()) == NULL) {
687                                 fprintf(stderr, "Error, can't parse 'standard'"
688                                                 " DH parameters\n");
689                                 return 0;
690                         }
691                         fprintf(stderr, "Info, using 'standard' DH parameters\n");
692                         goto do_it;
693                 }
694                 if(strcmp(dh_special, "generate") != 0)
695                         /* This shouldn't happen - screening values is handled
696                          * in main(). */
697                         abort();
698                 fprintf(stderr, "Info, generating DH parameters ... ");
699                 fflush(stderr);
700                 if((dh = DH_generate_parameters(512, DH_GENERATOR_5,
701                                         NULL, NULL)) == NULL) {
702                         fprintf(stderr, "error!\n");
703                         return 0;
704                 }
705                 fprintf(stderr, "complete\n");
706                 goto do_it;
707         }
708         /* So, we're loading dh_file */
709         if((fp = fopen(dh_file, "r")) == NULL) {
710                 fprintf(stderr, "Error, couldn't open '%s' for DH parameters\n",
711                                 dh_file);
712                 return 0;
713         }
714         dh = PEM_read_DHparams(fp, NULL, NULL, NULL);
715         fclose(fp);
716         if(dh == NULL) {
717                 fprintf(stderr, "Error, could not parse DH parameters from '%s'\n",
718                                 dh_file);
719                 return 0;
720         }
721         fprintf(stderr, "Info, using DH parameters from file '%s'\n", dh_file);
722 do_it:
723         SSL_CTX_set_tmp_dh(ctx, dh);
724         DH_free(dh);
725         return 1;
726 }
727
728 static SSL_CTX *initialise_ssl_ctx(int server_mode, const char *engine_id,
729                 const char *CAfile, const char *cert, const char *key,
730                 const char *dcert, const char *dkey, const char *cipher_list,
731                 const char *dh_file, const char *dh_special, int tmp_rsa,
732                 int ctx_options, int out_state, int out_verify, int verify_mode,
733                 unsigned int verify_depth)
734 {
735         SSL_CTX *ctx = NULL, *ret = NULL;
736         SSL_METHOD *meth;
737         ENGINE *e = NULL;
738
739         OpenSSL_add_ssl_algorithms();
740         SSL_load_error_strings();
741
742         meth = (server_mode ? SSLv23_server_method() : SSLv23_client_method());
743         if(meth == NULL)
744                 goto err;
745         if(engine_id) {
746                 ENGINE_load_builtin_engines();
747                 if((e = ENGINE_by_id(engine_id)) == NULL) {
748                         fprintf(stderr, "Error obtaining '%s' engine, openssl "
749                                         "errors follow\n", engine_id);
750                         goto err;
751                 }
752                 if(!ENGINE_set_default(e, ENGINE_METHOD_ALL)) {
753                         fprintf(stderr, "Error assigning '%s' engine, openssl "
754                                         "errors follow\n", engine_id);
755                         goto err;
756                 }
757                 ENGINE_free(e);
758         }
759         if((ctx = SSL_CTX_new(meth)) == NULL)
760                 goto err;
761         /* cacert */
762         if(CAfile) {
763                 if(!X509_STORE_load_locations(SSL_CTX_get_cert_store(ctx),
764                                         CAfile, NULL)) {
765                         fprintf(stderr, "Error loading CA cert(s) in '%s'\n",
766                                         CAfile);
767                         goto err;
768                 }
769                 fprintf(stderr, "Info, operating with CA cert(s) in '%s'\n",
770                                 CAfile);
771         } else
772                 fprintf(stderr, "Info, operating without a CA cert(-list)\n");
773         if(!SSL_CTX_set_default_verify_paths(ctx)) {
774                 fprintf(stderr, "Error setting default verify paths\n");
775                 goto err;
776         }
777
778         /* cert and key */
779         if((cert || key) && !ctx_set_cert(ctx, cert, key))
780                 goto err;
781         /* dcert and dkey */
782         if((dcert || dkey) && !ctx_set_cert(ctx, dcert, dkey))
783                 goto err;
784         /* temporary RSA key generation */
785         if(tmp_rsa)
786                 SSL_CTX_set_tmp_rsa_callback(ctx, cb_generate_tmp_rsa);
787
788         /* cipher_list */
789         if(cipher_list) {
790                 if(!SSL_CTX_set_cipher_list(ctx, cipher_list)) {
791                         fprintf(stderr, "Error setting cipher list '%s'\n",
792                                         cipher_list);
793                         goto err;
794                 }
795                 fprintf(stderr, "Info, set cipher list '%s'\n", cipher_list);
796         } else
797                 fprintf(stderr, "Info, operating with default cipher list\n");
798
799         /* dh_file & dh_special */
800         if((dh_file || dh_special) && !ctx_set_dh(ctx, dh_file, dh_special))
801                 goto err;
802
803         /* ctx_options */
804         SSL_CTX_set_options(ctx, ctx_options);
805
806         /* out_state (output of SSL handshake states to screen). */
807         if(out_state)
808                 cb_ssl_info_set_output(stderr);
809
810         /* out_verify */
811         if(out_verify > 0) {
812                 cb_ssl_verify_set_output(stderr);
813                 cb_ssl_verify_set_level(out_verify);
814         }
815
816         /* verify_depth */
817         cb_ssl_verify_set_depth(verify_depth);
818
819         /* Success! (includes setting verify_mode) */
820         SSL_CTX_set_info_callback(ctx, cb_ssl_info);
821         SSL_CTX_set_verify(ctx, verify_mode, cb_ssl_verify);
822         ret = ctx;
823 err:
824         if(!ret) {
825                 ERR_print_errors_fp(stderr);
826                 if(ctx)
827                         SSL_CTX_free(ctx);
828         }
829         return ret;
830 }
831
832 /*****************/
833 /* Selector bits */
834 /*****************/
835
836 static void selector_sets_init(select_sets_t *s)
837 {
838         s->max = 0;
839         FD_ZERO(&s->reads);
840         FD_ZERO(&s->sends);
841         FD_ZERO(&s->excepts);
842 }
843 static void selector_init(tunala_selector_t *selector)
844 {
845         selector_sets_init(&selector->last_selected);
846         selector_sets_init(&selector->next_select);
847 }
848
849 #define SEL_EXCEPTS 0x00
850 #define SEL_READS   0x01
851 #define SEL_SENDS   0x02
852 static void selector_add_raw_fd(tunala_selector_t *s, int fd, int flags)
853 {
854         FD_SET(fd, &s->next_select.excepts);
855         if(flags & SEL_READS)
856                 FD_SET(fd, &s->next_select.reads);
857         if(flags & SEL_SENDS)
858                 FD_SET(fd, &s->next_select.sends);
859         /* Adjust "max" */
860         if(s->next_select.max < (fd + 1))
861                 s->next_select.max = fd + 1;
862 }
863
864 static void selector_add_listener(tunala_selector_t *selector, int fd)
865 {
866         selector_add_raw_fd(selector, fd, SEL_READS);
867 }
868
869 static void selector_add_tunala(tunala_selector_t *s, tunala_item_t *t)
870 {
871         /* Set clean read if sm.clean_in is not full */
872         if(t->clean_read != -1) {
873                 selector_add_raw_fd(s, t->clean_read,
874                         (buffer_full(state_machine_get_buffer(&t->sm,
875                                 SM_CLEAN_IN)) ? SEL_EXCEPTS : SEL_READS));
876         }
877         /* Set clean send if sm.clean_out is not empty */
878         if(t->clean_send != -1) {
879                 selector_add_raw_fd(s, t->clean_send,
880                         (buffer_empty(state_machine_get_buffer(&t->sm,
881                                 SM_CLEAN_OUT)) ? SEL_EXCEPTS : SEL_SENDS));
882         }
883         /* Set dirty read if sm.dirty_in is not full */
884         if(t->dirty_read != -1) {
885                 selector_add_raw_fd(s, t->dirty_read,
886                         (buffer_full(state_machine_get_buffer(&t->sm,
887                                 SM_DIRTY_IN)) ? SEL_EXCEPTS : SEL_READS));
888         }
889         /* Set dirty send if sm.dirty_out is not empty */
890         if(t->dirty_send != -1) {
891                 selector_add_raw_fd(s, t->dirty_send,
892                         (buffer_empty(state_machine_get_buffer(&t->sm,
893                                 SM_DIRTY_OUT)) ? SEL_EXCEPTS : SEL_SENDS));
894         }
895 }
896
897 static int selector_select(tunala_selector_t *selector)
898 {
899         memcpy(&selector->last_selected, &selector->next_select,
900                         sizeof(select_sets_t));
901         selector_sets_init(&selector->next_select);
902         return select(selector->last_selected.max,
903                         &selector->last_selected.reads,
904                         &selector->last_selected.sends,
905                         &selector->last_selected.excepts, NULL);
906 }
907
908 /* This returns -1 for error, 0 for no new connections, or 1 for success, in
909  * which case *newfd is populated. */
910 static int selector_get_listener(tunala_selector_t *selector, int fd, int *newfd)
911 {
912         if(FD_ISSET(fd, &selector->last_selected.excepts))
913                 return -1;
914         if(!FD_ISSET(fd, &selector->last_selected.reads))
915                 return 0;
916         if((*newfd = ip_accept_connection(fd)) == -1)
917                 return -1;
918         return 1;
919 }
920
921 /************************/
922 /* "Tunala" world stuff */
923 /************************/
924
925 static int tunala_world_make_room(tunala_world_t *world)
926 {
927         unsigned int newsize;
928         tunala_item_t *newarray;
929
930         if(world->tunnels_used < world->tunnels_size)
931                 return 1;
932         newsize = (world->tunnels_size == 0 ? 16 :
933                         ((world->tunnels_size * 3) / 2));
934         if((newarray = malloc(newsize * sizeof(tunala_item_t))) == NULL)
935                 return 0;
936         memset(newarray, 0, newsize * sizeof(tunala_item_t));
937         if(world->tunnels_used > 0)
938                 memcpy(newarray, world->tunnels,
939                         world->tunnels_used * sizeof(tunala_item_t));
940         if(world->tunnels_size > 0)
941                 free(world->tunnels);
942         /* migrate */
943         world->tunnels = newarray;
944         world->tunnels_size = newsize;
945         return 1;
946 }
947
948 static int tunala_world_new_item(tunala_world_t *world, int fd,
949                 const char *ip, unsigned short port, int flipped)
950 {
951         tunala_item_t *item;
952         int newfd;
953         SSL *new_ssl = NULL;
954
955         if(!tunala_world_make_room(world))
956                 return 0;
957         if((new_ssl = SSL_new(world->ssl_ctx)) == NULL) {
958                 fprintf(stderr, "Error creating new SSL\n");
959                 ERR_print_errors_fp(stderr);
960                 return 0;
961         }
962         item = world->tunnels + (world->tunnels_used++);
963         state_machine_init(&item->sm);
964         item->clean_read = item->clean_send =
965                 item->dirty_read = item->dirty_send = -1;
966         if((newfd = ip_create_connection_split(ip, port)) == -1)
967                 goto err;
968         /* Which way round? If we're a server, "fd" is the dirty side and the
969          * connection we open is the clean one. For a client, it's the other way
970          * around. Unless, of course, we're "flipped" in which case everything
971          * gets reversed. :-) */
972         if((world->server_mode && !flipped) ||
973                         (!world->server_mode && flipped)) {
974                 item->dirty_read = item->dirty_send = fd;
975                 item->clean_read = item->clean_send = newfd;
976         } else {
977                 item->clean_read = item->clean_send = fd;
978                 item->dirty_read = item->dirty_send = newfd;
979         }
980         /* We use the SSL's "app_data" to indicate a call-back induced "kill" */
981         SSL_set_app_data(new_ssl, NULL);
982         if(!state_machine_set_SSL(&item->sm, new_ssl, world->server_mode))
983                 goto err;
984         return 1;
985 err:
986         tunala_world_del_item(world, world->tunnels_used - 1);
987         return 0;
988
989 }
990
991 static void tunala_world_del_item(tunala_world_t *world, unsigned int idx)
992 {
993         tunala_item_t *item = world->tunnels + idx;
994         if(item->clean_read != -1)
995                 close(item->clean_read);
996         if(item->clean_send != item->clean_read)
997                 close(item->clean_send);
998         item->clean_read = item->clean_send = -1;
999         if(item->dirty_read != -1)
1000                 close(item->dirty_read);
1001         if(item->dirty_send != item->dirty_read)
1002                 close(item->dirty_send);
1003         item->dirty_read = item->dirty_send = -1;
1004         state_machine_close(&item->sm);
1005         /* OK, now we fix the item array */
1006         if(idx + 1 < world->tunnels_used)
1007                 /* We need to scroll entries to the left */
1008                 memmove(world->tunnels + idx,
1009                                 world->tunnels + (idx + 1),
1010                                 (world->tunnels_used - (idx + 1)) *
1011                                         sizeof(tunala_item_t));
1012         world->tunnels_used--;
1013 }
1014
1015 static int tunala_item_io(tunala_selector_t *selector, tunala_item_t *item)
1016 {
1017         int c_r, c_s, d_r, d_s; /* Four boolean flags */
1018
1019         /* Take ourselves out of the gene-pool if there was an except */
1020         if((item->clean_read != -1) && FD_ISSET(item->clean_read,
1021                                 &selector->last_selected.excepts))
1022                 return 0;
1023         if((item->clean_send != -1) && FD_ISSET(item->clean_send,
1024                                 &selector->last_selected.excepts))
1025                 return 0;
1026         if((item->dirty_read != -1) && FD_ISSET(item->dirty_read,
1027                                 &selector->last_selected.excepts))
1028                 return 0;
1029         if((item->dirty_send != -1) && FD_ISSET(item->dirty_send,
1030                                 &selector->last_selected.excepts))
1031                 return 0;
1032         /* Grab our 4 IO flags */
1033         c_r = c_s = d_r = d_s = 0;
1034         if(item->clean_read != -1)
1035                 c_r = FD_ISSET(item->clean_read, &selector->last_selected.reads);
1036         if(item->clean_send != -1)
1037                 c_s = FD_ISSET(item->clean_send, &selector->last_selected.sends);
1038         if(item->dirty_read != -1)
1039                 d_r = FD_ISSET(item->dirty_read, &selector->last_selected.reads);
1040         if(item->dirty_send != -1)
1041                 d_s = FD_ISSET(item->dirty_send, &selector->last_selected.sends);
1042         /* If no IO has happened for us, skip needless data looping */
1043         if(!c_r && !c_s && !d_r && !d_s)
1044                 return 1;
1045         if(c_r)
1046                 c_r = (buffer_from_fd(state_machine_get_buffer(&item->sm,
1047                                 SM_CLEAN_IN), item->clean_read) <= 0);
1048         if(c_s)
1049                 c_s = (buffer_to_fd(state_machine_get_buffer(&item->sm,
1050                                 SM_CLEAN_OUT), item->clean_send) <= 0);
1051         if(d_r)
1052                 d_r = (buffer_from_fd(state_machine_get_buffer(&item->sm,
1053                                 SM_DIRTY_IN), item->dirty_read) <= 0);
1054         if(d_s)
1055                 d_s = (buffer_to_fd(state_machine_get_buffer(&item->sm,
1056                                 SM_DIRTY_OUT), item->dirty_send) <= 0);
1057         /* If any of the flags is non-zero, that means they need closing */
1058         if(c_r) {
1059                 close(item->clean_read);
1060                 if(item->clean_send == item->clean_read)
1061                         item->clean_send = -1;
1062                 item->clean_read = -1;
1063         }
1064         if(c_s && (item->clean_send != -1)) {
1065                 close(item->clean_send);
1066                 if(item->clean_send == item->clean_read)
1067                         item->clean_read = -1;
1068                 item->clean_send = -1;
1069         }
1070         if(d_r) {
1071                 close(item->dirty_read);
1072                 if(item->dirty_send == item->dirty_read)
1073                         item->dirty_send = -1;
1074                 item->dirty_read = -1;
1075         }
1076         if(d_s && (item->dirty_send != -1)) {
1077                 close(item->dirty_send);
1078                 if(item->dirty_send == item->dirty_read)
1079                         item->dirty_read = -1;
1080                 item->dirty_send = -1;
1081         }
1082         /* This function name is attributed to the term donated by David
1083          * Schwartz on openssl-dev, message-ID:
1084          * <NCBBLIEPOCNJOAEKBEAKEEDGLIAA.davids@webmaster.com>. :-) */
1085         if(!state_machine_churn(&item->sm))
1086                 /* If the SSL closes, it will also zero-out the _in buffers
1087                  * and will in future process just outgoing data. As and
1088                  * when the outgoing data has gone, it will return zero
1089                  * here to tell us to bail out. */
1090                 return 0;
1091         /* Otherwise, we return zero if both sides are dead. */
1092         if(((item->clean_read == -1) || (item->clean_send == -1)) &&
1093                         ((item->dirty_read == -1) || (item->dirty_send == -1)))
1094                 return 0;
1095         /* If only one side closed, notify the SSL of this so it can take
1096          * appropriate action. */
1097         if((item->clean_read == -1) || (item->clean_send == -1)) {
1098                 if(!state_machine_close_clean(&item->sm))
1099                         return 0;
1100         }
1101         if((item->dirty_read == -1) || (item->dirty_send == -1)) {
1102                 if(!state_machine_close_dirty(&item->sm))
1103                         return 0;
1104         }
1105         return 1;
1106 }
1107