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