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, str0);
 190         fprintf(stderr, "\n");
 191         return 1;
 192 }
 193
 194 static int err_str1(const char *str0, const char *str1)
 195 {
 196         fprintf(stderr, str0, str1);
 197         fprintf(stderr, "\n");
 198         return 1;
 199 }
 200
 201 static int parse_max_tunnels(const char *s, unsigned int *maxtunnels)
 202 {
 203         unsigned long l;
 204         char *temp;
 205         l = strtoul(s, &temp, 10);
 206         if((temp == s) || (*temp != '\0') || (l < 1) || (l > 1024)) {
 207                 fprintf(stderr, "Error, '%s' is an invalid value for "
 208                                 "maxtunnels\n", s);
 209                 return 0;
 210         }
 211         *maxtunnels = (unsigned int)l;
 212         return 1;
 213 }
 214
 215 static int parse_server_mode(const char *s, int *servermode)
 216 {
 217         unsigned long l;
 218         char *temp;
 219         l = strtoul(s, &temp, 10);
 220         if((temp == s) || (*temp != '\0') || (l > 1)) {
 221                 fprintf(stderr, "Error, '%s' is an invalid value for the "
 222                                 "server mode\n", s);
 223                 return 0;
 224         }
 225         *servermode = (int)l;
 226         return 1;
 227 }
 228
 229 static int parse_dh_special(const char *s, const char **dh_special)
 230 {
 231         if((strcmp(s, "NULL") == 0) || (strcmp(s, "generate") == 0) ||
 232                         (strcmp(s, "standard") == 0)) {
 233                 *dh_special = s;
 234                 return 1;
 235         }
 236         fprintf(stderr, "Error, '%s' is an invalid value for 'dh_special'\n", s);
 237         return 0;
 238 }
 239
 240 static int parse_verify_level(const char *s, unsigned int *verify_level)
 241 {
 242         unsigned long l;
 243         char *temp;
 244         l = strtoul(s, &temp, 10);
 245         if((temp == s) || (*temp != '\0') || (l > 3)) {
 246                 fprintf(stderr, "Error, '%s' is an invalid value for "
 247                                 "out_verify\n", s);
 248                 return 0;
 249         }
 250         *verify_level = (unsigned int)l;
 251         return 1;
 252 }
 253
 254 static int parse_verify_depth(const char *s, unsigned int *verify_depth)
 255 {
 256         unsigned long l;
 257         char *temp;
 258         l = strtoul(s, &temp, 10);
 259         if((temp == s) || (*temp != '\0') || (l < 1) || (l > 50)) {
 260                 fprintf(stderr, "Error, '%s' is an invalid value for "
 261                                 "verify_depth\n", s);
 262                 return 0;
 263         }
 264         *verify_depth = (unsigned int)l;
 265         return 1;
 266 }
 267
 268 /* Some fprintf format strings used when tunnels close */
 269 static const char *io_stats_client_dirty =
 270 "    SSL (network) traffic to/from server; %8lu bytes in, %8lu bytes out\n";
 271 static const char *io_stats_client_clean =
 272 "    tunnelled data to/from server;        %8lu bytes in, %8lu bytes out\n";
 273 static const char *io_stats_server_dirty =
 274 "    SSL (network) traffic to/from client; %8lu bytes in, %8lu bytes out\n";
 275 static const char *io_stats_server_clean =
 276 "    tunnelled data to/from client;        %8lu bytes in, %8lu bytes out\n";
 277
 278 int main(int argc, char *argv[])
 279 {
 280         unsigned int loop;
 281         int newfd;
 282         tunala_world_t world;
 283         tunala_item_t *t_item;
 284         unsigned char *proxy_ip;
 285         unsigned short proxy_port;
 286         /* Overridables */
 287         const char *proxyhost = def_proxyhost;
 288         const char *listenhost = def_listenhost;
 289         unsigned int max_tunnels = def_max_tunnels;
 290         const char *cacert = def_cacert;
 291         const char *cert = def_cert;
 292         const char *key = def_key;
 293         const char *dcert = def_dcert;
 294         const char *dkey = def_dkey;
 295         const char *engine_id = def_engine_id;
 296         int server_mode = def_server_mode;
 297         const char *cipher_list = def_cipher_list;
 298         const char *dh_file = def_dh_file;
 299         const char *dh_special = def_dh_special;
 300         int ctx_options = def_ctx_options;
 301         int verify_mode = def_verify_mode;
 302         unsigned int verify_depth = def_verify_depth;
 303         int out_state = def_out_state;
 304         unsigned int out_verify = def_out_verify;
 305         int out_totals = def_out_totals;
 306
 307 /* Parse command-line arguments */
 308 next_arg:
 309         argc--; argv++;
 310         if(argc > 0) {
 311                 if(strcmp(*argv, "-listen") == 0) {
 312                         if(argc < 2)
 313                                 return usage("-listen requires an argument", 0);
 314                         argc--; argv++;
 315                         listenhost = *argv;
 316                         goto next_arg;
 317                 } else if(strcmp(*argv, "-proxy") == 0) {
 318                         if(argc < 2)
 319                                 return usage("-proxy requires an argument", 0);
 320                         argc--; argv++;
 321                         proxyhost = *argv;
 322                         goto next_arg;
 323                 } else if(strcmp(*argv, "-maxtunnels") == 0) {
 324                         if(argc < 2)
 325                                 return usage("-maxtunnels requires an argument", 0);
 326                         argc--; argv++;
 327                         if(!parse_max_tunnels(*argv, &max_tunnels))
 328                                 return 1;
 329                         goto next_arg;
 330                 } else if(strcmp(*argv, "-cacert") == 0) {
 331                         if(argc < 2)
 332                                 return usage("-cacert requires an argument", 0);
 333                         argc--; argv++;
 334                         if(strcmp(*argv, "NULL") == 0)
 335                                 cacert = NULL;
 336                         else
 337                                 cacert = *argv;
 338                         goto next_arg;
 339                 } else if(strcmp(*argv, "-cert") == 0) {
 340                         if(argc < 2)
 341                                 return usage("-cert requires an argument", 0);
 342                         argc--; argv++;
 343                         if(strcmp(*argv, "NULL") == 0)
 344                                 cert = NULL;
 345                         else
 346                                 cert = *argv;
 347                         goto next_arg;
 348                 } else if(strcmp(*argv, "-key") == 0) {
 349                         if(argc < 2)
 350                                 return usage("-key requires an argument", 0);
 351                         argc--; argv++;
 352                         if(strcmp(*argv, "NULL") == 0)
 353                                 key = NULL;
 354                         else
 355                                 key = *argv;
 356                         goto next_arg;
 357                 } else if(strcmp(*argv, "-dcert") == 0) {
 358                         if(argc < 2)
 359                                 return usage("-dcert requires an argument", 0);
 360                         argc--; argv++;
 361                         if(strcmp(*argv, "NULL") == 0)
 362                                 dcert = NULL;
 363                         else
 364                                 dcert = *argv;
 365                         goto next_arg;
 366                 } else if(strcmp(*argv, "-dkey") == 0) {
 367                         if(argc < 2)
 368                                 return usage("-dkey requires an argument", 0);
 369                         argc--; argv++;
 370                         if(strcmp(*argv, "NULL") == 0)
 371                                 dkey = NULL;
 372                         else
 373                                 dkey = *argv;
 374                         goto next_arg;
 375                 } else if(strcmp(*argv, "-engine") == 0) {
 376                         if(argc < 2)
 377                                 return usage("-engine requires an argument", 0);
 378                         argc--; argv++;
 379                         engine_id = *argv;
 380                         goto next_arg;
 381                 } else if(strcmp(*argv, "-server") == 0) {
 382                         if(argc < 2)
 383                                 return usage("-server requires an argument", 0);
 384                         argc--; argv++;
 385                         if(!parse_server_mode(*argv, &server_mode))
 386                                 return 1;
 387                         goto next_arg;
 388                 } else if(strcmp(*argv, "-cipher") == 0) {
 389                         if(argc < 2)
 390                                 return usage("-cipher requires an argument", 0);
 391                         argc--; argv++;
 392                         cipher_list = *argv;
 393                         goto next_arg;
 394                 } else if(strcmp(*argv, "-dh_file") == 0) {
 395                         if(argc < 2)
 396                                 return usage("-dh_file requires an argument", 0);
 397                         if(dh_special)
 398                                 return usage("cannot mix -dh_file with "
 399                                                 "-dh_special", 0);
 400                         argc--; argv++;
 401                         dh_file = *argv;
 402                         goto next_arg;
 403                 } else if(strcmp(*argv, "-dh_special") == 0) {
 404                         if(argc < 2)
 405                                 return usage("-dh_special requires an argument", 0);
 406                         if(dh_file)
 407                                 return usage("cannot mix -dh_file with "
 408                                                 "-dh_special", 0);
 409                         argc--; argv++;
 410                         if(!parse_dh_special(*argv, &dh_special))
 411                                 return 1;
 412                         goto next_arg;
 413                 } else if(strcmp(*argv, "-no_ssl2") == 0) {
 414                         ctx_options |= SSL_OP_NO_SSLv2;
 415                         goto next_arg;
 416                 } else if(strcmp(*argv, "-no_ssl3") == 0) {
 417                         ctx_options |= SSL_OP_NO_SSLv3;
 418                         goto next_arg;
 419                 } else if(strcmp(*argv, "-no_tls1") == 0) {
 420                         ctx_options |= SSL_OP_NO_TLSv1;
 421                         goto next_arg;
 422                 } else if(strcmp(*argv, "-v_peer") == 0) {
 423                         verify_mode |= SSL_VERIFY_PEER;
 424                         goto next_arg;
 425                 } else if(strcmp(*argv, "-v_strict") == 0) {
 426                         verify_mode |= SSL_VERIFY_FAIL_IF_NO_PEER_CERT;
 427                         goto next_arg;
 428                 } else if(strcmp(*argv, "-v_once") == 0) {
 429                         verify_mode |= SSL_VERIFY_CLIENT_ONCE;
 430                         goto next_arg;
 431                 } else if(strcmp(*argv, "-v_depth") == 0) {
 432                         if(argc < 2)
 433                                 return usage("-v_depth requires an argument", 0);
 434                         argc--; argv++;
 435                         if(!parse_verify_depth(*argv, &verify_depth))
 436                                 return 1;
 437                         goto next_arg;
 438                 } else if(strcmp(*argv, "-out_state") == 0) {
 439                         out_state = 1;
 440                         goto next_arg;
 441                 } else if(strcmp(*argv, "-out_verify") == 0) {
 442                         if(argc < 2)
 443                                 return usage("-out_verify requires an argument", 0);
 444                         argc--; argv++;
 445                         if(!parse_verify_level(*argv, &out_verify))
 446                                 return 1;
 447                         goto next_arg;
 448                 } else if(strcmp(*argv, "-out_totals") == 0) {
 449                         out_totals = 1;
 450                         goto next_arg;
 451                 } else if((strcmp(*argv, "-h") == 0) ||
 452                                 (strcmp(*argv, "-help") == 0) ||
 453                                 (strcmp(*argv, "-?") == 0)) {
 454                         fprintf(stderr, "%s\n", helpstring);
 455                         return 0;
 456                 } else
 457                         return usage(*argv, 1);
 458         }
 459
 460         /* Initialise network stuff */
 461         if(!ip_initialise())
 462                 return err_str0("ip_initialise failed");
 463         err_str0("ip_initialise succeeded");
 464         /* Create the SSL_CTX */
 465         if((world.ssl_ctx = initialise_ssl_ctx(server_mode, engine_id,
 466                         cacert, cert, key, dcert, dkey, cipher_list, dh_file,
 467                         dh_special, ctx_options, out_state, out_verify,
 468                         verify_mode, verify_depth)) == NULL)
 469                 return err_str1("initialise_ssl_ctx(engine_id=%s) failed",
 470                         (engine_id == NULL) ? "NULL" : engine_id);
 471         err_str1("initialise_ssl_ctx(engine_id=%s) succeeded",
 472                         (engine_id == NULL) ? "NULL" : engine_id);
 473         /* Create the listener */
 474         if((world.listen_fd = ip_create_listener(listenhost)) == -1)
 475                 return err_str1("ip_create_listener(%s) failed", listenhost);
 476         err_str1("ip_create_listener(%s) succeeded", listenhost);
 477         if(!ip_parse_address(proxyhost, &proxy_ip, &proxy_port, 0))
 478                 return err_str1("ip_parse_address(%s) failed", proxyhost);
 479         err_str1("ip_parse_address(%s) succeeded", proxyhost);
 480         fprintf(stderr, "Info - proxying to %d.%d.%d.%d:%d\n",
 481                         (int)proxy_ip[0], (int)proxy_ip[1],
 482                         (int)proxy_ip[2], (int)proxy_ip[3], (int)proxy_port);
 483         fprintf(stderr, "Info - set maxtunnels to %d\n", (int)max_tunnels);
 484         fprintf(stderr, "Info - set to operate as an SSL %s\n",
 485                         (server_mode ? "server" : "client"));
 486         /* Initialise the rest of the stuff */
 487         world.tunnels_used = world.tunnels_size = 0;
 488         world.tunnels = NULL;
 489         world.server_mode = server_mode;
 490         selector_init(&world.selector);
 491
 492 /* We're ready to loop */
 493 main_loop:
 494         /* Should we listen for *new* tunnels? */
 495         if(world.tunnels_used < max_tunnels)
 496                 selector_add_listener(&world.selector, world.listen_fd);
 497         /* We should add in our existing tunnels */
 498         for(loop = 0; loop < world.tunnels_used; loop++)
 499                 selector_add_tunala(&world.selector, world.tunnels + loop);
 500         /* Now do the select */
 501         switch(selector_select(&world.selector)) {
 502         case -1:
 503                 fprintf(stderr, "selector_select returned a badness error.\n");
 504                 abort();
 505         case 0:
 506                 fprintf(stderr, "Warn, selector_select returned 0 - signal??\n");
 507                 goto main_loop;
 508         default:
 509                 break;
 510         }
 511         /* Accept new connection if we should and can */
 512         if((world.tunnels_used < max_tunnels) && (selector_get_listener(
 513                                         &world.selector, world.listen_fd,
 514                                         &newfd) == 1)) {
 515                 /* We have a new connection */
 516                 if(!tunala_world_new_item(&world, newfd,
 517                                         proxy_ip, proxy_port))
 518                         fprintf(stderr, "tunala_world_new_item failed\n");
 519                 else
 520                         fprintf(stderr, "Info, new tunnel opened, now up to "
 521                                         "%d\n", world.tunnels_used);
 522         }
 523         /* Give each tunnel its moment, note the while loop is because it makes
 524          * the logic easier than with "for" to deal with an array that may shift
 525          * because of deletes. */
 526         loop = 0;
 527         t_item = world.tunnels;
 528         while(loop < world.tunnels_used) {
 529                 if(!tunala_item_io(&world.selector, t_item)) {
 530                         /* We're closing whether for reasons of an error or a
 531                          * natural close. Don't increment loop or t_item because
 532                          * the next item is moving to us! */
 533                         if(!out_totals)
 534                                 goto skip_totals;
 535                         fprintf(stderr, "Tunnel closing, traffic stats follow\n");
 536                         /* Display the encrypted (over the network) stats */
 537                         fprintf(stderr, (server_mode ? io_stats_server_dirty :
 538                                                 io_stats_client_dirty),
 539                                 buffer_total_in(state_machine_get_buffer(
 540                                                 &t_item->sm,SM_DIRTY_IN)),
 541                                 buffer_total_out(state_machine_get_buffer(
 542                                                 &t_item->sm,SM_DIRTY_OUT)));
 543                         /* Display the local (tunnelled) stats. NB: Data we
 544                          * *receive* is data sent *out* of the state_machine on
 545                          * its 'clean' side. Hence the apparent back-to-front
 546                          * OUT/IN mixup here :-) */
 547                         fprintf(stderr, (server_mode ? io_stats_server_clean :
 548                                                 io_stats_client_clean),
 549                                 buffer_total_out(state_machine_get_buffer(
 550                                                 &t_item->sm,SM_CLEAN_OUT)),
 551                                 buffer_total_in(state_machine_get_buffer(
 552                                                 &t_item->sm,SM_CLEAN_IN)));
 553 skip_totals:
 554                         tunala_world_del_item(&world, loop);
 555                         fprintf(stderr, "Info, tunnel closed, down to %d\n",
 556                                         world.tunnels_used);
 557                 }
 558                 else {
 559                         /* Move to the next item */
 560                         loop++;
 561                         t_item++;
 562                 }
 563         }
 564         goto main_loop;
 565         /* Should never get here */
 566         abort();
 567         return 1;
 568 }
 569
 570 /****************/
 571 /* OpenSSL bits */
 572 /****************/
 573
 574 static int ctx_set_cert(SSL_CTX *ctx, const char *cert, const char *key)
 575 {
 576         FILE *fp = NULL;
 577         X509 *x509 = NULL;
 578         EVP_PKEY *pkey = NULL;
 579         int toret = 0; /* Assume an error */
 580
 581         /* cert */
 582         if(cert) {
 583                 if((fp = fopen(cert, "r")) == NULL) {
 584                         fprintf(stderr, "Error opening cert file '%s'\n", cert);
 585                         goto err;
 586                 }
 587                 if(!PEM_read_X509(fp, &x509, NULL, NULL)) {
 588                         fprintf(stderr, "Error reading PEM cert from '%s'\n",
 589                                         cert);
 590                         goto err;
 591                 }
 592                 if(!SSL_CTX_use_certificate(ctx, x509)) {
 593                         fprintf(stderr, "Error, cert in '%s' can not be used\n",
 594                                         cert);
 595                         goto err;
 596                 }
 597                 /* Clear the FILE* for reuse in the "key" code */
 598                 fclose(fp);
 599                 fp = NULL;
 600                 fprintf(stderr, "Info, operating with cert in '%s'\n", cert);
 601                 /* If a cert was given without matching key, we assume the same
 602                  * file contains the required key. */
 603                 if(!key)
 604                         key = cert;
 605         } else {
 606                 if(key)
 607                         fprintf(stderr, "Error, can't specify a key without a "
 608                                         "corresponding certificate\n");
 609                 else
 610                         fprintf(stderr, "Error, ctx_set_cert called with "
 611                                         "NULLs!\n");
 612                 goto err;
 613         }
 614         /* key */
 615         if(key) {
 616                 if((fp = fopen(key, "r")) == NULL) {
 617                         fprintf(stderr, "Error opening key file '%s'\n", key);
 618                         goto err;
 619                 }
 620                 if(!PEM_read_PrivateKey(fp, &pkey, NULL, NULL)) {
 621                         fprintf(stderr, "Error reading PEM key from '%s'\n",
 622                                         key);
 623                         goto err;
 624                 }
 625                 if(!SSL_CTX_use_PrivateKey(ctx, pkey)) {
 626                         fprintf(stderr, "Error, key in '%s' can not be used\n",
 627                                         key);
 628                         goto err;
 629                 }
 630                 fprintf(stderr, "Info, operating with key in '%s'\n", key);
 631         } else
 632                 fprintf(stderr, "Info, operating without a cert or key\n");
 633         /* Success */
 634         toret = 1; err:
 635         if(x509)
 636                 X509_free(x509);
 637         if(pkey)
 638                 EVP_PKEY_free(pkey);
 639         if(fp)
 640                 fclose(fp);
 641         return toret;
 642 }
 643
 644 static int ctx_set_dh(SSL_CTX *ctx, const char *dh_file, const char *dh_special)
 645 {
 646         DH *dh = NULL;
 647         FILE *fp = NULL;
 648
 649         if(dh_special) {
 650                 if(strcmp(dh_special, "NULL") == 0)
 651                         return 1;
 652                 if(strcmp(dh_special, "standard") == 0) {
 653                         if((dh = get_dh512()) == NULL) {
 654                                 fprintf(stderr, "Error, can't parse 'standard'"
 655                                                 " DH parameters\n");
 656                                 return 0;
 657                         }
 658                         fprintf(stderr, "Info, using 'standard' DH parameters\n");
 659                         goto do_it;
 660                 }
 661                 if(strcmp(dh_special, "generate") != 0)
 662                         /* This shouldn't happen - screening values is handled
 663                          * in main(). */
 664                         abort();
 665                 fprintf(stderr, "Info, generating DH parameters ... ");
 666                 fflush(stderr);
 667                 if((dh = DH_generate_parameters(512, DH_GENERATOR_5,
 668                                         NULL, NULL)) == NULL) {
 669                         fprintf(stderr, "error!\n");
 670                         return 0;
 671                 }
 672                 fprintf(stderr, "complete\n");
 673                 goto do_it;
 674         }
 675         /* So, we're loading dh_file */
 676         if((fp = fopen(dh_file, "r")) == NULL) {
 677                 fprintf(stderr, "Error, couldn't open '%s' for DH parameters\n",
 678                                 dh_file);
 679                 return 0;
 680         }
 681         dh = PEM_read_DHparams(fp, NULL, NULL, NULL);
 682         fclose(fp);
 683         if(dh == NULL) {
 684                 fprintf(stderr, "Error, could not parse DH parameters from '%s'\n",
 685                                 dh_file);
 686                 return 0;
 687         }
 688         fprintf(stderr, "Info, using DH parameters from file '%s'\n", dh_file);
 689 do_it:
 690         SSL_CTX_set_tmp_dh(ctx, dh);
 691         DH_free(dh);
 692         return 1;
 693 }
 694
 695 static SSL_CTX *initialise_ssl_ctx(int server_mode, const char *engine_id,
 696                 const char *CAfile, const char *cert, const char *key,
 697                 const char *dcert, const char *dkey, const char *cipher_list,
 698                 const char *dh_file, const char *dh_special, int ctx_options,
 699                 int out_state, int out_verify, int verify_mode,
 700                 unsigned int verify_depth)
 701 {
 702         SSL_CTX *ctx, *ret = NULL;
 703         SSL_METHOD *meth;
 704         ENGINE *e = NULL;
 705
 706         OpenSSL_add_ssl_algorithms();
 707         SSL_load_error_strings();
 708
 709         meth = (server_mode ? SSLv23_server_method() : SSLv23_client_method());
 710         if(meth == NULL)
 711                 goto err;
 712         if(engine_id) {
 713                 if((e = ENGINE_by_id(engine_id)) == NULL) {
 714                         fprintf(stderr, "Error obtaining '%s' engine, openssl "
 715                                         "errors follow\n", engine_id);
 716                         goto err;
 717                 }
 718                 if(!ENGINE_set_default(e, ENGINE_METHOD_ALL)) {
 719                         fprintf(stderr, "Error assigning '%s' engine, openssl "
 720                                         "errors follow\n", engine_id);
 721                         goto err;
 722                 }
 723                 ENGINE_free(e);
 724         }
 725         if((ctx = SSL_CTX_new(meth)) == NULL)
 726                 goto err;
 727         /* cacert */
 728         if(CAfile) {
 729                 if(!X509_STORE_load_locations(SSL_CTX_get_cert_store(ctx),
 730                                         CAfile, NULL)) {
 731                         fprintf(stderr, "Error loading CA cert(s) in '%s'\n",
 732                                         CAfile);
 733                         goto err;
 734                 }
 735                 fprintf(stderr, "Info, operating with CA cert(s) in '%s'\n",
 736                                 CAfile);
 737         } else
 738                 fprintf(stderr, "Info, operating without a CA cert(-list)\n");
 739         if(!SSL_CTX_set_default_verify_paths(ctx)) {
 740                 fprintf(stderr, "Error setting default verify paths\n");
 741                 goto err;
 742         }
 743
 744         /* cert and key */
 745         if((cert || key) && !ctx_set_cert(ctx, cert, key))
 746                 goto err;
 747         /* dcert and dkey */
 748         if((dcert || dkey) && !ctx_set_cert(ctx, dcert, dkey))
 749                 goto err;
 750
 751         /* cipher_list */
 752         if(cipher_list) {
 753                 if(!SSL_CTX_set_cipher_list(ctx, cipher_list)) {
 754                         fprintf(stderr, "Error setting cipher list '%s'\n",
 755                                         cipher_list);
 756                         goto err;
 757                 }
 758                 fprintf(stderr, "Info, set cipher list '%s'\n", cipher_list);
 759         } else
 760                 fprintf(stderr, "Info, operating with default cipher list\n");
 761
 762         /* dh_file & dh_special */
 763         if((dh_file || dh_special) && !ctx_set_dh(ctx, dh_file, dh_special))
 764                 goto err;
 765
 766         /* ctx_options */
 767         SSL_CTX_set_options(ctx, ctx_options);
 768
 769         /* out_state (output of SSL handshake states to screen). */
 770         if(out_state)
 771                 cb_ssl_info_set_output(stderr);
 772
 773         /* out_verify */
 774         if(out_verify > 0) {
 775                 cb_ssl_verify_set_output(stderr);
 776                 cb_ssl_verify_set_level(out_verify);
 777         }
 778
 779         /* verify_depth */
 780         cb_ssl_verify_set_depth(verify_depth);
 781
 782         /* Success! (includes setting verify_mode) */
 783         SSL_CTX_set_info_callback(ctx, cb_ssl_info);
 784         SSL_CTX_set_verify(ctx, verify_mode, cb_ssl_verify);
 785         ret = ctx;
 786 err:
 787         if(!ret) {
 788                 ERR_print_errors_fp(stderr);
 789                 if(ctx)
 790                         SSL_CTX_free(ctx);
 791         }
 792         return ret;
 793 }
 794
 795 /*****************/
 796 /* Selector bits */
 797 /*****************/
 798
 799 static void selector_sets_init(select_sets_t *s)
 800 {
 801         s->max = 0;
 802         FD_ZERO(&s->reads);
 803         FD_ZERO(&s->sends);
 804         FD_ZERO(&s->excepts);
 805 }
 806 static void selector_init(tunala_selector_t *selector)
 807 {
 808         selector_sets_init(&selector->last_selected);
 809         selector_sets_init(&selector->next_select);
 810 }
 811
 812 #define SEL_EXCEPTS 0x00
 813 #define SEL_READS   0x01
 814 #define SEL_SENDS   0x02
 815 static void selector_add_raw_fd(tunala_selector_t *s, int fd, int flags)
 816 {
 817         FD_SET(fd, &s->next_select.excepts);
 818         if(flags & SEL_READS)
 819                 FD_SET(fd, &s->next_select.reads);
 820         if(flags & SEL_SENDS)
 821                 FD_SET(fd, &s->next_select.sends);
 822         /* Adjust "max" */
 823         if(s->next_select.max < (fd + 1))
 824                 s->next_select.max = fd + 1;
 825 }
 826
 827 static void selector_add_listener(tunala_selector_t *selector, int fd)
 828 {
 829         selector_add_raw_fd(selector, fd, SEL_READS);
 830 }
 831
 832 static void selector_add_tunala(tunala_selector_t *s, tunala_item_t *t)
 833 {
 834         /* Set clean read if sm.clean_in is not full */
 835         if(t->clean_read != -1) {
 836                 selector_add_raw_fd(s, t->clean_read,
 837                         (buffer_full(state_machine_get_buffer(&t->sm,
 838                                 SM_CLEAN_IN)) ? SEL_EXCEPTS : SEL_READS));
 839         }
 840         /* Set clean send if sm.clean_out is not empty */
 841         if(t->clean_send != -1) {
 842                 selector_add_raw_fd(s, t->clean_send,
 843                         (buffer_empty(state_machine_get_buffer(&t->sm,
 844                                 SM_CLEAN_OUT)) ? SEL_EXCEPTS : SEL_SENDS));
 845         }
 846         /* Set dirty read if sm.dirty_in is not full */
 847         if(t->dirty_read != -1) {
 848                 selector_add_raw_fd(s, t->dirty_read,
 849                         (buffer_full(state_machine_get_buffer(&t->sm,
 850                                 SM_DIRTY_IN)) ? SEL_EXCEPTS : SEL_READS));
 851         }
 852         /* Set dirty send if sm.dirty_out is not empty */
 853         if(t->dirty_send != -1) {
 854                 selector_add_raw_fd(s, t->dirty_send,
 855                         (buffer_empty(state_machine_get_buffer(&t->sm,
 856                                 SM_DIRTY_OUT)) ? SEL_EXCEPTS : SEL_SENDS));
 857         }
 858 }
 859
 860 static int selector_select(tunala_selector_t *selector)
 861 {
 862         memcpy(&selector->last_selected, &selector->next_select,
 863                         sizeof(select_sets_t));
 864         selector_sets_init(&selector->next_select);
 865         return select(selector->last_selected.max,
 866                         &selector->last_selected.reads,
 867                         &selector->last_selected.sends,
 868                         &selector->last_selected.excepts, NULL);
 869 }
 870
 871 /* This returns -1 for error, 0 for no new connections, or 1 for success, in
 872  * which case *newfd is populated. */
 873 static int selector_get_listener(tunala_selector_t *selector, int fd, int *newfd)
 874 {
 875         if(FD_ISSET(fd, &selector->last_selected.excepts))
 876                 return -1;
 877         if(!FD_ISSET(fd, &selector->last_selected.reads))
 878                 return 0;
 879         if((*newfd = ip_accept_connection(fd)) == -1)
 880                 return -1;
 881         return 1;
 882 }
 883
 884 /************************/
 885 /* "Tunala" world stuff */
 886 /************************/
 887
 888 static int tunala_world_make_room(tunala_world_t *world)
 889 {
 890         unsigned int newsize;
 891         tunala_item_t *newarray;
 892
 893         if(world->tunnels_used < world->tunnels_size)
 894                 return 1;
 895         newsize = (world->tunnels_size == 0 ? 16 :
 896                         ((world->tunnels_size * 3) / 2));
 897         if((newarray = malloc(newsize * sizeof(tunala_item_t))) == NULL)
 898                 return 0;
 899         memset(newarray, 0, newsize * sizeof(tunala_item_t));
 900         if(world->tunnels_used > 0)
 901                 memcpy(newarray, world->tunnels,
 902                         world->tunnels_used * sizeof(tunala_item_t));
 903         if(world->tunnels_size > 0)
 904                 free(world->tunnels);
 905         /* migrate */
 906         world->tunnels = newarray;
 907         world->tunnels_size = newsize;
 908         return 1;
 909 }
 910
 911 static int tunala_world_new_item(tunala_world_t *world, int fd,
 912                 const unsigned char *ip, unsigned short port)
 913 {
 914         tunala_item_t *item;
 915         int newfd;
 916         SSL *new_ssl = NULL;
 917
 918         if(!tunala_world_make_room(world))
 919                 return 0;
 920         if((new_ssl = SSL_new(world->ssl_ctx)) == NULL) {
 921                 fprintf(stderr, "Error creating new SSL\n");
 922                 ERR_print_errors_fp(stderr);
 923                 return 0;
 924         }
 925         item = world->tunnels + (world->tunnels_used++);
 926         state_machine_init(&item->sm);
 927         item->clean_read = item->clean_send =
 928                 item->dirty_read = item->dirty_send = -1;
 929         if((newfd = ip_create_connection_split(ip, port)) == -1)
 930                 goto err;
 931         /* Which way round? If we're a server, "fd" is the dirty side and the
 932          * connection we open is the clean one. For a client, it's the other way
 933          * around. */
 934         if(world->server_mode) {
 935                 item->dirty_read = item->dirty_send = fd;
 936                 item->clean_read = item->clean_send = newfd;
 937         } else {
 938                 item->clean_read = item->clean_send = fd;
 939                 item->dirty_read = item->dirty_send = newfd;
 940         }
 941         /* We use the SSL's "app_data" to indicate a call-back induced "kill" */
 942         SSL_set_app_data(new_ssl, NULL);
 943         if(!state_machine_set_SSL(&item->sm, new_ssl, world->server_mode))
 944                 goto err;
 945         return 1;
 946 err:
 947         tunala_world_del_item(world, world->tunnels_used - 1);
 948         return 0;
 949
 950 }
 951
 952 static void tunala_world_del_item(tunala_world_t *world, unsigned int idx)
 953 {
 954         tunala_item_t *item = world->tunnels + idx;
 955         if(item->clean_read != -1)
 956                 close(item->clean_read);
 957         if(item->clean_send != item->clean_read)
 958                 close(item->clean_send);
 959         item->clean_read = item->clean_send = -1;
 960         if(item->dirty_read != -1)
 961                 close(item->dirty_read);
 962         if(item->dirty_send != item->dirty_read)
 963                 close(item->dirty_send);
 964         item->dirty_read = item->dirty_send = -1;
 965         state_machine_close(&item->sm);
 966         /* OK, now we fix the item array */
 967         if(idx + 1 < world->tunnels_used)
 968                 /* We need to scroll entries to the left */
 969                 memmove(world->tunnels + idx,
 970                                 world->tunnels + (idx + 1),
 971                                 (world->tunnels_used - (idx + 1)) *
 972                                         sizeof(tunala_item_t));
 973         world->tunnels_used--;
 974 }
 975
 976 static int tunala_item_io(tunala_selector_t *selector, tunala_item_t *item)
 977 {
 978         int c_r, c_s, d_r, d_s; /* Four boolean flags */
 979
 980         /* Take ourselves out of the gene-pool if there was an except */
 981         if((item->clean_read != -1) && FD_ISSET(item->clean_read,
 982                                 &selector->last_selected.excepts))
 983                 return 0;
 984         if((item->clean_send != -1) && FD_ISSET(item->clean_send,
 985                                 &selector->last_selected.excepts))
 986                 return 0;
 987         if((item->dirty_read != -1) && FD_ISSET(item->dirty_read,
 988                                 &selector->last_selected.excepts))
 989                 return 0;
 990         if((item->dirty_send != -1) && FD_ISSET(item->dirty_send,
 991                                 &selector->last_selected.excepts))
 992                 return 0;
 993         /* Grab our 4 IO flags */
 994         c_r = c_s = d_r = d_s = 0;
 995         if(item->clean_read != -1)
 996                 c_r = FD_ISSET(item->clean_read, &selector->last_selected.reads);
 997         if(item->clean_send != -1)
 998                 c_s = FD_ISSET(item->clean_send, &selector->last_selected.sends);
 999         if(item->dirty_read != -1)
1000                 d_r = FD_ISSET(item->dirty_read, &selector->last_selected.reads);
1001         if(item->dirty_send != -1)
1002                 d_s = FD_ISSET(item->dirty_send, &selector->last_selected.sends);
1003         /* If no IO has happened for us, skip needless data looping */
1004         if(!c_r && !c_s && !d_r && !d_s)
1005                 return 1;
1006         if(c_r)
1007                 c_r = (buffer_from_fd(state_machine_get_buffer(&item->sm,
1008                                 SM_CLEAN_IN), item->clean_read) <= 0);
1009         if(c_s)
1010                 c_s = (buffer_to_fd(state_machine_get_buffer(&item->sm,
1011                                 SM_CLEAN_OUT), item->clean_send) <= 0);
1012         if(d_r)
1013                 d_r = (buffer_from_fd(state_machine_get_buffer(&item->sm,
1014                                 SM_DIRTY_IN), item->dirty_read) <= 0);
1015         if(d_s)
1016                 d_s = (buffer_to_fd(state_machine_get_buffer(&item->sm,
1017                                 SM_DIRTY_OUT), item->dirty_send) <= 0);
1018         /* If any of the flags is non-zero, that means they need closing */
1019         if(c_r) {
1020                 close(item->clean_read);
1021                 if(item->clean_send == item->clean_read)
1022                         item->clean_send = -1;
1023                 item->clean_read = -1;
1024         }
1025         if(c_s && (item->clean_send != -1)) {
1026                 close(item->clean_send);
1027                 if(item->clean_send == item->clean_read)
1028                         item->clean_read = -1;
1029                 item->clean_send = -1;
1030         }
1031         if(d_r) {
1032                 close(item->dirty_read);
1033                 if(item->dirty_send == item->dirty_read)
1034                         item->dirty_send = -1;
1035                 item->dirty_read = -1;
1036         }
1037         if(d_s && (item->dirty_send != -1)) {
1038                 close(item->dirty_send);
1039                 if(item->dirty_send == item->dirty_read)
1040                         item->dirty_read = -1;
1041                 item->dirty_send = -1;
1042         }
1043         /* This function name is attributed to the term donated by David
1044          * Schwartz on openssl-dev, message-ID:
1045          * <NCBBLIEPOCNJOAEKBEAKEEDGLIAA.davids@webmaster.com>. :-) */
1046         if(!state_machine_churn(&item->sm))
1047                 /* If the SSL closes, it will also zero-out the _in buffers
1048                  * and will in future process just outgoing data. As and
1049                  * when the outgoing data has gone, it will return zero
1050                  * here to tell us to bail out. */
1051                 return 0;
1052         /* Otherwise, we return zero if both sides are dead. */
1053         if(((item->clean_read == -1) || (item->clean_send == -1)) &&
1054                         ((item->dirty_read == -1) || (item->dirty_send == -1)))
1055                 return 0;
1056         /* If only one side closed, notify the SSL of this so it can take
1057          * appropriate action. */
1058         if((item->clean_read == -1) || (item->clean_send == -1)) {
1059                 if(!state_machine_close_clean(&item->sm))
1060                         return 0;
1061         }
1062         if((item->dirty_read == -1) || (item->dirty_send == -1)) {
1063                 if(!state_machine_close_dirty(&item->sm))
1064                         return 0;
1065         }
1066         return 1;
1067 }
1068