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