lib/client.c

   1 /*
   2  * libwebsockets - small server side websockets and web server implementation
   3  *
   4  * Copyright (C) 2010-2013 Andy Green <andy@warmcat.com>
   5  *
   6  *  This library is free software; you can redistribute it and/or
   7  *  modify it under the terms of the GNU Lesser General Public
   8  *  License as published by the Free Software Foundation:
   9  *  version 2.1 of the License.
  10  *
  11  *  This library is distributed in the hope that it will be useful,
  12  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14  *  Lesser General Public License for more details.
  15  *
  16  *  You should have received a copy of the GNU Lesser General Public
  17  *  License along with this library; if not, write to the Free Software
  18  *  Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
  19  *  MA  02110-1301  USA
  20  */
  21
  22 #include "private-libwebsockets.h"
  23
  24 #ifdef WIN32
  25 #include <tchar.h>
  26 #include <io.h>
  27 #else
  28 #ifdef LWS_BUILTIN_GETIFADDRS
  29 #include <getifaddrs.h>
  30 #else
  31 #include <ifaddrs.h>
  32 #endif
  33 #include <sys/un.h>
  34 #include <sys/socket.h>
  35 #include <netdb.h>
  36 #endif
  37
  38 #ifdef LWS_OPENSSL_SUPPORT
  39 extern int openssl_websocket_private_data_index;
  40 #endif
  41
  42 int lws_client_socket_service(struct libwebsocket_context *context, struct libwebsocket *wsi, struct pollfd *pollfd)
  43 {
  44         int n;
  45         char pkt[1024];
  46         char *p = &pkt[0];
  47         int len;
  48         char c;
  49 #ifdef LWS_OPENSSL_SUPPORT
  50         char ssl_err_buf[512];
  51 #endif
  52
  53         switch (wsi->mode) {
  54
  55         case LWS_CONNMODE_WS_CLIENT_WAITING_PROXY_REPLY:
  56
  57                 /* handle proxy hung up on us */
  58
  59                 if (pollfd->revents & (POLLERR | POLLHUP)) {
  60
  61                         lwsl_warn("Proxy connection %p (fd=%d) dead\n",
  62                                 (void *)wsi, pollfd->fd);
  63
  64                         libwebsocket_close_and_free_session(context, wsi,
  65                                                      LWS_CLOSE_STATUS_NOSTATUS);
  66                         return 1;
  67                 }
  68
  69                 n = recv(wsi->sock, pkt, sizeof pkt, 0);
  70                 if (n < 0) {
  71                         libwebsocket_close_and_free_session(context, wsi,
  72                                                      LWS_CLOSE_STATUS_NOSTATUS);
  73                         lwsl_err("ERROR reading from proxy socket\n");
  74                         return 1;
  75                 }
  76
  77                 pkt[13] = '\0';
  78                 if (strcmp(pkt, "HTTP/1.0 200 ") != 0) {
  79                         libwebsocket_close_and_free_session(context, wsi,
  80                                                      LWS_CLOSE_STATUS_NOSTATUS);
  81                         lwsl_err("ERROR from proxy: %s\n", pkt);
  82                         return 1;
  83                 }
  84
  85                 /* clear his proxy connection timeout */
  86
  87                 libwebsocket_set_timeout(wsi, NO_PENDING_TIMEOUT, 0);
  88
  89                 /* fallthru */
  90
  91         case LWS_CONNMODE_WS_CLIENT_ISSUE_HANDSHAKE:
  92
  93                 /*
  94                  * we are under PENDING_TIMEOUT_SENT_CLIENT_HANDSHAKE
  95                  * timeout protection set in client-handshake.c
  96                  */
  97
  98         #ifdef LWS_OPENSSL_SUPPORT
  99
 100                 /*
 101                  * take care of our libwebsocket_callback_on_writable
 102                  * happening at a time when there's no real connection yet
 103                  */
 104
 105                 pollfd->events &= ~POLLOUT;
 106
 107                 /* external POLL support via protocol 0 */
 108                 context->protocols[0].callback(context, wsi,
 109                         LWS_CALLBACK_CLEAR_MODE_POLL_FD,
 110                         (void *)(long)wsi->sock, NULL, POLLOUT);
 111
 112                 /* we can retry this... so just cook the SSL BIO the first time */
 113
 114                 if (wsi->use_ssl && !wsi->ssl) {
 115
 116                         wsi->ssl = SSL_new(context->ssl_client_ctx);
 117                         wsi->client_bio = BIO_new_socket(wsi->sock,
 118                                                                    BIO_NOCLOSE);
 119                         SSL_set_bio(wsi->ssl, wsi->client_bio, wsi->client_bio);
 120
 121                         SSL_set_ex_data(wsi->ssl,
 122                                         openssl_websocket_private_data_index,
 123                                                                        context);
 124                 }
 125
 126                 if (wsi->use_ssl) {
 127                         n = SSL_connect(wsi->ssl);
 128
 129                         if (n < 0) {
 130                                 n = SSL_get_error(wsi->ssl, n);
 131
 132                                 if (n == SSL_ERROR_WANT_READ ||
 133                                         n == SSL_ERROR_WANT_WRITE) {
 134                                         /*
 135                                          * wants us to retry connect due to state of the
 136                                          * underlying ssl layer... but since it may be
 137                                          * stalled on blocked write, no incoming data may
 138                                          * arrive to trigger the retry.  Force (possibly
 139                                          * many if the SSL state persists in returning the
 140                                          * condition code, but other sockets are getting
 141                                          * serviced inbetweentimes) us to get called back
 142                                          * when writable.
 143                                          */
 144
 145                                         lwsl_info("SSL_connect -> SSL_ERROR_WANT_... retrying\n");
 146                                         libwebsocket_callback_on_writable(context, wsi);
 147
 148                                         return 0; /* no error */
 149                                 }
 150                                 n = -1;
 151                         }
 152
 153                         if (n <= 0) {
 154                                 /*
 155                                  * retry if new data comes until we
 156                                  * run into the connection timeout or win
 157                                  */
 158
 159                                 lwsl_err("SSL connect error %s\n",
 160                                         ERR_error_string(ERR_get_error(),
 161                                                                   ssl_err_buf));
 162                                 return 0;
 163                         }
 164
 165                         n = SSL_get_verify_result(wsi->ssl);
 166                         if ((n != X509_V_OK) && (
 167                                 n != X509_V_ERR_DEPTH_ZERO_SELF_SIGNED_CERT ||
 168                                                            wsi->use_ssl != 2)) {
 169
 170                                 lwsl_err("server's cert didn't "
 171                                                            "look good %d\n", n);
 172                                 libwebsocket_close_and_free_session(context,
 173                                                 wsi, LWS_CLOSE_STATUS_NOSTATUS);
 174                                 return 1;
 175                         }
 176                 } else
 177                         wsi->ssl = NULL;
 178         #endif
 179
 180                 p = libwebsockets_generate_client_handshake(context, wsi, p);
 181                 if (p == NULL)
 182                         return 1;
 183
 184                 /* send our request to the server */
 185
 186         #ifdef LWS_OPENSSL_SUPPORT
 187                 if (wsi->use_ssl)
 188                         n = SSL_write(wsi->ssl, pkt, p - pkt);
 189                 else
 190         #endif
 191                         n = send(wsi->sock, pkt, p - pkt, 0);
 192
 193                 if (n < 0) {
 194                         lwsl_debug("ERROR writing to client socket\n");
 195                         libwebsocket_close_and_free_session(context, wsi,
 196                                                      LWS_CLOSE_STATUS_NOSTATUS);
 197                         return 1;
 198                 }
 199
 200                 wsi->parser_state = WSI_TOKEN_NAME_PART;
 201                 wsi->mode = LWS_CONNMODE_WS_CLIENT_WAITING_SERVER_REPLY;
 202                 libwebsocket_set_timeout(wsi,
 203                                 PENDING_TIMEOUT_AWAITING_SERVER_RESPONSE, AWAITING_TIMEOUT);
 204
 205                 break;
 206
 207         case LWS_CONNMODE_WS_CLIENT_WAITING_SERVER_REPLY:
 208
 209                 /* handle server hung up on us */
 210
 211                 if (pollfd->revents & (POLLERR | POLLHUP)) {
 212
 213                         lwsl_debug("Server connection %p (fd=%d) dead\n",
 214                                 (void *)wsi, pollfd->fd);
 215
 216                         goto bail3;
 217                 }
 218
 219
 220                 /* interpret the server response */
 221
 222                 /*
 223                  *  HTTP/1.1 101 Switching Protocols
 224                  *  Upgrade: websocket
 225                  *  Connection: Upgrade
 226                  *  Sec-WebSocket-Accept: me89jWimTRKTWwrS3aRrL53YZSo=
 227                  *  Sec-WebSocket-Nonce: AQIDBAUGBwgJCgsMDQ4PEC==
 228                  *  Sec-WebSocket-Protocol: chat
 229                  */
 230
 231                 /*
 232                  * we have to take some care here to only take from the
 233                  * socket bytewise.  The browser may (and has been seen to
 234                  * in the case that onopen() performs websocket traffic)
 235                  * coalesce both handshake response and websocket traffic
 236                  * in one packet, since at that point the connection is
 237                  * definitively ready from browser pov.
 238                  */
 239
 240                 len = 1;
 241                 while (wsi->parser_state != WSI_PARSING_COMPLETE && len > 0) {
 242 #ifdef LWS_OPENSSL_SUPPORT
 243                         if (wsi->use_ssl)
 244                                 len = SSL_read(wsi->ssl, &c, 1);
 245                          else
 246 #endif
 247                                 len = recv(wsi->sock, &c, 1, 0);
 248
 249                         libwebsocket_parse(wsi, c);
 250                 }
 251
 252                 /*
 253                  * hs may also be coming in multiple packets, there is a 5-sec
 254                  * libwebsocket timeout still active here too, so if parsing did
 255                  * not complete just wait for next packet coming in this state
 256                  */
 257
 258                 if (wsi->parser_state != WSI_PARSING_COMPLETE)
 259                         break;
 260
 261                 /*
 262                  * otherwise deal with the handshake.  If there's any
 263                  * packet traffic already arrived we'll trigger poll() again
 264                  * right away and deal with it that way
 265                  */
 266
 267                 return lws_client_interpret_server_handshake(context, wsi);
 268
 269 bail3:
 270                 if (wsi->c_protocol)
 271                         free(wsi->c_protocol);
 272                 libwebsocket_close_and_free_session(context, wsi,
 273                                                     LWS_CLOSE_STATUS_NOSTATUS);
 274                 return 1;
 275
 276         case LWS_CONNMODE_WS_CLIENT_WAITING_EXTENSION_CONNECT:
 277                 lwsl_ext("LWS_CONNMODE_WS_CLIENT_WAITING_EXTENSION_CONNECT\n");
 278                 break;
 279
 280         case LWS_CONNMODE_WS_CLIENT_PENDING_CANDIDATE_CHILD:
 281                 lwsl_ext("LWS_CONNMODE_WS_CLIENT_PENDING_CANDIDATE_CHILD\n");
 282                 break;
 283         default:
 284                 break;
 285         }
 286
 287         return 0;
 288 }
 289
 290
 291 /*
 292  * In-place str to lower case
 293  */
 294
 295 static void
 296 strtolower(char *s)
 297 {
 298         while (*s) {
 299                 *s = tolower(*s);
 300                 s++;
 301         }
 302 }
 303
 304 int
 305 lws_client_interpret_server_handshake(struct libwebsocket_context *context,
 306                 struct libwebsocket *wsi)
 307 {
 308         unsigned char buf[LWS_SEND_BUFFER_PRE_PADDING + 1 +
 309                         MAX_BROADCAST_PAYLOAD + LWS_SEND_BUFFER_POST_PADDING];
 310         char pkt[1024];
 311         char *p = &pkt[0];
 312         const char *pc;
 313         const char *c;
 314         int more = 1;
 315         int okay = 0;
 316         char ext_name[128];
 317         struct libwebsocket_extension *ext;
 318         void *v;
 319         int len = 0;
 320         int n;
 321         static const char magic_websocket_04_masking_guid[] =
 322                                          "61AC5F19-FBBA-4540-B96F-6561F1AB40A8";
 323
 324         /*
 325          * 00 / 76 -->
 326          *
 327          * HTTP/1.1 101 WebSocket Protocol Handshake
 328          * Upgrade: WebSocket
 329          * Connection: Upgrade
 330          * Sec-WebSocket-Origin: http://127.0.0.1
 331          * Sec-WebSocket-Location: ws://127.0.0.1:9999/socket.io/websocket
 332          *
 333          * xxxxxxxxxxxxxxxx
 334          */
 335
 336         if (wsi->ietf_spec_revision == 0) {
 337                 if (!wsi->utf8_token[WSI_TOKEN_HTTP].token_len ||
 338                         !wsi->utf8_token[WSI_TOKEN_UPGRADE].token_len ||
 339                         !wsi->utf8_token[WSI_TOKEN_CHALLENGE].token_len ||
 340                         !wsi->utf8_token[WSI_TOKEN_CONNECTION].token_len ||
 341                         (!wsi->utf8_token[WSI_TOKEN_PROTOCOL].token_len &&
 342                         wsi->c_protocol != NULL)) {
 343                         lwsl_parser("libwebsocket_client_handshake "
 344                                         "missing required header(s)\n");
 345                         pkt[len] = '\0';
 346                         lwsl_parser("%s", pkt);
 347                         goto bail3;
 348                 }
 349
 350                 strtolower(wsi->utf8_token[WSI_TOKEN_HTTP].token);
 351                 if (strncmp(wsi->utf8_token[WSI_TOKEN_HTTP].token, "101", 3)) {
 352                         lwsl_warn("libwebsocket_client_handshake "
 353                                 "server sent bad HTTP response '%s'\n",
 354                                 wsi->utf8_token[WSI_TOKEN_HTTP].token);
 355                         goto bail3;
 356                 }
 357
 358                 if (wsi->utf8_token[WSI_TOKEN_CHALLENGE].token_len < 16) {
 359                         lwsl_parser("libwebsocket_client_handshake "
 360                                 "challenge reply too short %d\n",
 361                                 wsi->utf8_token[
 362                                         WSI_TOKEN_CHALLENGE].token_len);
 363                         pkt[len] = '\0';
 364                         lwsl_parser("%s", pkt);
 365                         goto bail3;
 366
 367                 }
 368
 369                 goto select_protocol;
 370         }
 371
 372         /*
 373          * well, what the server sent looked reasonable for syntax.
 374          * Now let's confirm it sent all the necessary headers
 375          */
 376 #if 0
 377         lwsl_parser("WSI_TOKEN_HTTP: %d\n",
 378                                     wsi->utf8_token[WSI_TOKEN_HTTP].token_len);
 379         lwsl_parser("WSI_TOKEN_UPGRADE: %d\n",
 380                                  wsi->utf8_token[WSI_TOKEN_UPGRADE].token_len);
 381         lwsl_parser("WSI_TOKEN_CONNECTION: %d\n",
 382                               wsi->utf8_token[WSI_TOKEN_CONNECTION].token_len);
 383         lwsl_parser("WSI_TOKEN_ACCEPT: %d\n",
 384                                   wsi->utf8_token[WSI_TOKEN_ACCEPT].token_len);
 385         lwsl_parser("WSI_TOKEN_NONCE: %d\n",
 386                                    wsi->utf8_token[WSI_TOKEN_NONCE].token_len);
 387         lwsl_parser("WSI_TOKEN_PROTOCOL: %d\n",
 388                                 wsi->utf8_token[WSI_TOKEN_PROTOCOL].token_len);
 389 #endif
 390         if (!wsi->utf8_token[WSI_TOKEN_HTTP].token_len ||
 391             !wsi->utf8_token[WSI_TOKEN_UPGRADE].token_len ||
 392             !wsi->utf8_token[WSI_TOKEN_CONNECTION].token_len ||
 393             !wsi->utf8_token[WSI_TOKEN_ACCEPT].token_len ||
 394             (!wsi->utf8_token[WSI_TOKEN_NONCE].token_len &&
 395                                    wsi->ietf_spec_revision == 4) ||
 396             (!wsi->utf8_token[WSI_TOKEN_PROTOCOL].token_len &&
 397                                                     wsi->c_protocol != NULL)) {
 398                 lwsl_parser("libwebsocket_client_handshake "
 399                                         "missing required header(s)\n");
 400                 pkt[len] = '\0';
 401                 lwsl_parser("%s", pkt);
 402                 goto bail3;
 403         }
 404
 405         /*
 406          * Everything seems to be there, now take a closer look at what
 407          * is in each header
 408          */
 409
 410         strtolower(wsi->utf8_token[WSI_TOKEN_HTTP].token);
 411         if (strncmp(wsi->utf8_token[WSI_TOKEN_HTTP].token, "101", 3)) {
 412                 lwsl_warn("libwebsocket_client_handshake "
 413                                 "server sent bad HTTP response '%s'\n",
 414                                  wsi->utf8_token[WSI_TOKEN_HTTP].token);
 415                 goto bail3;
 416         }
 417
 418         strtolower(wsi->utf8_token[WSI_TOKEN_UPGRADE].token);
 419         if (strcmp(wsi->utf8_token[WSI_TOKEN_UPGRADE].token,
 420                                                          "websocket")) {
 421                 lwsl_warn("libwebsocket_client_handshake server "
 422                                 "sent bad Upgrade header '%s'\n",
 423                                   wsi->utf8_token[WSI_TOKEN_UPGRADE].token);
 424                 goto bail3;
 425         }
 426
 427         strtolower(wsi->utf8_token[WSI_TOKEN_CONNECTION].token);
 428         if (strcmp(wsi->utf8_token[WSI_TOKEN_CONNECTION].token,
 429                                                            "upgrade")) {
 430                 lwsl_warn("libwebsocket_client_handshake server "
 431                                 "sent bad Connection hdr '%s'\n",
 432                            wsi->utf8_token[WSI_TOKEN_CONNECTION].token);
 433                 goto bail3;
 434         }
 435
 436 select_protocol:
 437         pc = wsi->c_protocol;
 438         if (pc == NULL)
 439                 lwsl_parser("lws_client_interpret_server_handshake: "
 440                                                           "NULL c_protocol\n");
 441         else
 442                 lwsl_parser("lws_client_interpret_server_handshake: "
 443                                                       "cPprotocol='%s'\n", pc);
 444
 445         /*
 446          * confirm the protocol the server wants to talk was in the list
 447          * of protocols we offered
 448          */
 449
 450         if (!wsi->utf8_token[WSI_TOKEN_PROTOCOL].token_len) {
 451
 452                 lwsl_warn("lws_client_interpret_server_handshake "
 453                                                "WSI_TOKEN_PROTOCOL is null\n");
 454                 /*
 455                  * no protocol name to work from,
 456                  * default to first protocol
 457                  */
 458                 wsi->protocol = &context->protocols[0];
 459                 wsi->c_callback = wsi->protocol->callback;
 460                 free(wsi->c_protocol);
 461
 462                 goto check_extensions;
 463         }
 464
 465         while (*pc && !okay) {
 466                 if ((!strncmp(pc, wsi->utf8_token[WSI_TOKEN_PROTOCOL].token,
 467                  wsi->utf8_token[WSI_TOKEN_PROTOCOL].token_len)) &&
 468                  (pc[wsi->utf8_token[WSI_TOKEN_PROTOCOL].token_len] == ',' ||
 469                   pc[wsi->utf8_token[WSI_TOKEN_PROTOCOL].token_len] == '\0')) {
 470                         okay = 1;
 471                         continue;
 472                 }
 473                 while (*pc && *pc != ',')
 474                         pc++;
 475                 while (*pc && *pc != ' ')
 476                         pc++;
 477         }
 478
 479         /* done with him now */
 480
 481         if (wsi->c_protocol)
 482                 free(wsi->c_protocol);
 483
 484         if (!okay) {
 485                 lwsl_err("libwebsocket_client_handshake server "
 486                                         "sent bad protocol '%s'\n",
 487                                  wsi->utf8_token[WSI_TOKEN_PROTOCOL].token);
 488                 goto bail2;
 489         }
 490
 491         /*
 492          * identify the selected protocol struct and set it
 493          */
 494         n = 0;
 495         wsi->protocol = NULL;
 496         while (context->protocols[n].callback && !wsi->protocol) {  /* Stop after finding first one?? */
 497                 if (strcmp(wsi->utf8_token[WSI_TOKEN_PROTOCOL].token,
 498                                            context->protocols[n].name) == 0) {
 499                         wsi->protocol = &context->protocols[n];
 500                         wsi->c_callback = wsi->protocol->callback;
 501                 }
 502                 n++;
 503         }
 504
 505         if (wsi->protocol == NULL) {
 506                 lwsl_err("libwebsocket_client_handshake server "
 507                                 "requested protocol '%s', which we "
 508                                 "said we supported but we don't!\n",
 509                                  wsi->utf8_token[WSI_TOKEN_PROTOCOL].token);
 510                 goto bail2;
 511         }
 512
 513
 514 check_extensions:
 515
 516         /* instantiate the accepted extensions */
 517
 518         if (!wsi->utf8_token[WSI_TOKEN_EXTENSIONS].token_len) {
 519                 lwsl_ext("no client extenstions allowed by server\n");
 520                 goto check_accept;
 521         }
 522
 523         /*
 524          * break down the list of server accepted extensions
 525          * and go through matching them or identifying bogons
 526          */
 527
 528         c = wsi->utf8_token[WSI_TOKEN_EXTENSIONS].token;
 529         n = 0;
 530         while (more) {
 531
 532                 if (*c && (*c != ',' && *c != ' ' && *c != '\t')) {
 533                         ext_name[n] = *c++;
 534                         if (n < sizeof(ext_name) - 1)
 535                                 n++;
 536                         continue;
 537                 }
 538                 ext_name[n] = '\0';
 539                 if (!*c)
 540                         more = 0;
 541                 else {
 542                         c++;
 543                         if (!n)
 544                                 continue;
 545                 }
 546
 547                 /* check we actually support it */
 548
 549                 lwsl_ext("checking client ext %s\n", ext_name);
 550
 551                 n = 0;
 552                 ext = wsi->protocol->owning_server->extensions;
 553                 while (ext && ext->callback) {
 554
 555                         if (strcmp(ext_name, ext->name)) {
 556                                 ext++;
 557                                 continue;
 558                         }
 559
 560                         n = 1;
 561
 562                         lwsl_ext("instantiating client ext %s\n", ext_name);
 563
 564                         /* instantiate the extension on this conn */
 565
 566                         wsi->active_extensions_user[
 567                                 wsi->count_active_extensions] =
 568                                          malloc(ext->per_session_data_size);
 569                         if (wsi->active_extensions_user[
 570                                 wsi->count_active_extensions] == NULL) {
 571                                 lwsl_err("Out of mem\n");
 572                                 goto bail2;
 573                         }
 574                         memset(wsi->active_extensions_user[
 575                                 wsi->count_active_extensions], 0,
 576                                                     ext->per_session_data_size);
 577                         wsi->active_extensions[
 578                                   wsi->count_active_extensions] = ext;
 579
 580                         /* allow him to construct his context */
 581
 582                         ext->callback(wsi->protocol->owning_server,
 583                                 ext, wsi,
 584                                    LWS_EXT_CALLBACK_CLIENT_CONSTRUCT,
 585                                         wsi->active_extensions_user[
 586                                          wsi->count_active_extensions],
 587                                                                    NULL, 0);
 588
 589                         wsi->count_active_extensions++;
 590
 591                         ext++;
 592                 }
 593
 594                 if (n == 0) {
 595                         lwsl_warn("Server said we should use"
 596                                   "an unknown extension '%s'!\n", ext_name);
 597                         goto bail2;
 598                 }
 599
 600                 n = 0;
 601         }
 602
 603
 604 check_accept:
 605
 606         if (wsi->ietf_spec_revision == 0) {
 607
 608                 if (memcmp(wsi->initial_handshake_hash_base64,
 609                           wsi->utf8_token[WSI_TOKEN_CHALLENGE].token, 16)) {
 610                         lwsl_warn("libwebsocket_client_handshake "
 611                                            "failed 00 challenge compare\n");
 612                                 pkt[len] = '\0';
 613                                 lwsl_warn("%s", pkt);
 614                                 goto bail2;
 615                 }
 616
 617                 goto accept_ok;
 618         }
 619
 620         /*
 621          * Confirm his accept token is the one we precomputed
 622          */
 623
 624         if (strcmp(wsi->utf8_token[WSI_TOKEN_ACCEPT].token,
 625                                   wsi->initial_handshake_hash_base64)) {
 626                 lwsl_warn("libwebsocket_client_handshake server "
 627                         "sent bad ACCEPT '%s' vs computed '%s'\n",
 628                         wsi->utf8_token[WSI_TOKEN_ACCEPT].token,
 629                                         wsi->initial_handshake_hash_base64);
 630                 goto bail2;
 631         }
 632
 633         if (wsi->ietf_spec_revision == 4) {
 634                 /*
 635                  * Calculate the 04 masking key to use when
 636                  * sending data to server
 637                  */
 638
 639                 strcpy((char *)buf, wsi->key_b64);
 640                 p = (char *)buf + strlen(wsi->key_b64);
 641                 strcpy(p, wsi->utf8_token[WSI_TOKEN_NONCE].token);
 642                 p += wsi->utf8_token[WSI_TOKEN_NONCE].token_len;
 643                 strcpy(p, magic_websocket_04_masking_guid);
 644                 SHA1(buf, strlen((char *)buf), wsi->masking_key_04);
 645         }
 646 accept_ok:
 647
 648         /* allocate the per-connection user memory (if any) */
 649         if (wsi->protocol->per_session_data_size &&
 650                                           !libwebsocket_ensure_user_space(wsi))
 651                 goto bail2;
 652
 653         /* clear his proxy connection timeout */
 654
 655         libwebsocket_set_timeout(wsi, NO_PENDING_TIMEOUT, 0);
 656
 657         /* mark him as being alive */
 658
 659         wsi->state = WSI_STATE_ESTABLISHED;
 660         wsi->mode = LWS_CONNMODE_WS_CLIENT;
 661
 662         lwsl_debug("handshake OK for protocol %s\n", wsi->protocol->name);
 663
 664         /* call him back to inform him he is up */
 665
 666         wsi->protocol->callback(context, wsi,
 667                                 LWS_CALLBACK_CLIENT_ESTABLISHED,
 668                                                      wsi->user_space, NULL, 0);
 669
 670         /*
 671          * inform all extensions, not just active ones since they
 672          * already know
 673          */
 674
 675         ext = context->extensions;
 676
 677         while (ext && ext->callback) {
 678                 v = NULL;
 679                 for (n = 0; n < wsi->count_active_extensions; n++)
 680                         if (wsi->active_extensions[n] == ext)
 681                                 v = wsi->active_extensions_user[n];
 682
 683                 ext->callback(context, ext, wsi,
 684                           LWS_EXT_CALLBACK_ANY_WSI_ESTABLISHED, v, NULL, 0);
 685                 ext++;
 686         }
 687
 688         return 0;
 689
 690 bail3:
 691         if (wsi->c_protocol)
 692                 free(wsi->c_protocol);
 693
 694 bail2:
 695         if (wsi->c_callback) wsi->c_callback(context, wsi,
 696        LWS_CALLBACK_CLIENT_CONNECTION_ERROR,
 697                          wsi->user_space,
 698                          NULL, 0);
 699         libwebsocket_close_and_free_session(context, wsi,
 700                                                  LWS_CLOSE_STATUS_NOSTATUS);  // But this should be LWS_CLOSE_STATUS_PROTOCOL_ERR
 701
 702         return 1;
 703 }
 704
 705 void libwebsockets_00_spaceout(char *key, int spaces, int seed)
 706 {
 707         char *p;
 708
 709         key++;
 710         while (spaces--) {
 711                 if (*key && (seed & 1))
 712                         key++;
 713                 seed >>= 1;
 714
 715                 p = key + strlen(key);
 716                 while (p >= key) {
 717                         p[1] = p[0];
 718                         p--;
 719                 }
 720                 *key++ = ' ';
 721         }
 722 }
 723
 724 void libwebsockets_00_spam(char *key, int count, int seed)
 725 {
 726         char *p;
 727
 728         key++;
 729         while (count--) {
 730
 731                 if (*key && (seed & 1))
 732                         key++;
 733                 seed >>= 1;
 734
 735                 p = key + strlen(key);
 736                 while (p >= key) {
 737                         p[1] = p[0];
 738                         p--;
 739                 }
 740                 *key++ = 0x21 + ((seed & 0xffff) % 15);
 741                 /* 4 would use it up too fast.. not like it matters */
 742                 seed >>= 1;
 743         }
 744 }
 745
 746 char *
 747 libwebsockets_generate_client_handshake(struct libwebsocket_context *context,
 748                 struct libwebsocket *wsi, char *pkt)
 749 {
 750         char hash[20];
 751         char *p = pkt;
 752         int n;
 753         struct libwebsocket_extension *ext;
 754         struct libwebsocket_extension *ext1;
 755         int ext_count = 0;
 756         unsigned char buf[LWS_SEND_BUFFER_PRE_PADDING + 1 +
 757                          MAX_BROADCAST_PAYLOAD + LWS_SEND_BUFFER_POST_PADDING];
 758         static const char magic_websocket_guid[] =
 759                                          "258EAFA5-E914-47DA-95CA-C5AB0DC85B11";
 760
 761         /*
 762          * create the random key
 763          */
 764
 765         n = libwebsockets_get_random(context, hash, 16);
 766         if (n != 16) {
 767                 lwsl_err("Unable to read from random dev %s\n",
 768                                                 SYSTEM_RANDOM_FILEPATH);
 769                 free(wsi->c_path);
 770                 free(wsi->c_host);
 771                 if (wsi->c_origin)
 772                         free(wsi->c_origin);
 773                 if (wsi->c_protocol)
 774                         free(wsi->c_protocol);
 775                 libwebsocket_close_and_free_session(context, wsi,
 776                                              LWS_CLOSE_STATUS_NOSTATUS);
 777                 return NULL;
 778         }
 779
 780         lws_b64_encode_string(hash, 16, wsi->key_b64,
 781                                                    sizeof wsi->key_b64);
 782
 783         /*
 784          * 00 example client handshake
 785          *
 786          * GET /socket.io/websocket HTTP/1.1
 787          * Upgrade: WebSocket
 788          * Connection: Upgrade
 789          * Host: 127.0.0.1:9999
 790          * Origin: http://127.0.0.1
 791          * Sec-WebSocket-Key1: 1 0 2#0W 9 89 7  92 ^
 792          * Sec-WebSocket-Key2: 7 7Y 4328 B2v[8(z1
 793          * Cookie: socketio=websocket
 794          *
 795          * (Á®Ä0¶†≥
 796          *
 797          * 04 example client handshake
 798          *
 799          * GET /chat HTTP/1.1
 800          * Host: server.example.com
 801          * Upgrade: websocket
 802          * Connection: Upgrade
 803          * Sec-WebSocket-Key: dGhlIHNhbXBsZSBub25jZQ==
 804          * Sec-WebSocket-Origin: http://example.com
 805          * Sec-WebSocket-Protocol: chat, superchat
 806          * Sec-WebSocket-Version: 4
 807          */
 808
 809         p += sprintf(p, "GET %s HTTP/1.1\x0d\x0a", wsi->c_path);
 810
 811         p += sprintf(p, "Pragma: no-cache\x0d\x0a"
 812                                         "Cache-Control: no-cache\x0d\x0a");
 813
 814         if (wsi->ietf_spec_revision == 0) {
 815                 unsigned char spaces_1, spaces_2;
 816                 unsigned int max_1, max_2;
 817                 unsigned int num_1, num_2;
 818                 unsigned long product_1, product_2;
 819                 char key_1[40];
 820                 char key_2[40];
 821                 unsigned int seed;
 822                 unsigned int count;
 823                 char challenge[16];
 824
 825                 libwebsockets_get_random(context, &spaces_1, sizeof(char));
 826                 libwebsockets_get_random(context, &spaces_2, sizeof(char));
 827
 828                 spaces_1 = (spaces_1 % 12) + 1;
 829                 spaces_2 = (spaces_2 % 12) + 1;
 830
 831                 max_1 = 4294967295 / spaces_1;
 832                 max_2 = 4294967295 / spaces_2;
 833
 834                 libwebsockets_get_random(context, &num_1, sizeof(int));
 835                 libwebsockets_get_random(context, &num_2, sizeof(int));
 836
 837                 num_1 = (num_1 % max_1);
 838                 num_2 = (num_2 % max_2);
 839
 840                 challenge[0] = num_1 >> 24;
 841                 challenge[1] = num_1 >> 16;
 842                 challenge[2] = num_1 >> 8;
 843                 challenge[3] = num_1;
 844                 challenge[4] = num_2 >> 24;
 845                 challenge[5] = num_2 >> 16;
 846                 challenge[6] = num_2 >> 8;
 847                 challenge[7] = num_2;
 848
 849                 product_1 = num_1 * spaces_1;
 850                 product_2 = num_2 * spaces_2;
 851
 852                 sprintf(key_1, "%lu", product_1);
 853                 sprintf(key_2, "%lu", product_2);
 854
 855                 libwebsockets_get_random(context, &seed, sizeof(int));
 856                 libwebsockets_get_random(context, &count, sizeof(int));
 857
 858                 libwebsockets_00_spam(key_1, (count % 12) + 1, seed);
 859
 860                 libwebsockets_get_random(context, &seed, sizeof(int));
 861                 libwebsockets_get_random(context, &count, sizeof(int));
 862
 863                 libwebsockets_00_spam(key_2, (count % 12) + 1, seed);
 864
 865                 libwebsockets_get_random(context, &seed, sizeof(int));
 866
 867                 libwebsockets_00_spaceout(key_1, spaces_1, seed);
 868                 libwebsockets_00_spaceout(key_2, spaces_2, seed >> 16);
 869
 870                 p += sprintf(p, "Upgrade: WebSocket\x0d\x0a"
 871                         "Connection: Upgrade\x0d\x0aHost: %s\x0d\x0a",
 872                         wsi->c_host);
 873                 if (wsi->c_origin)
 874                         p += sprintf(p, "Origin: %s\x0d\x0a", wsi->c_origin);
 875
 876                 if (wsi->c_protocol)
 877                         p += sprintf(p, "Sec-WebSocket-Protocol: %s"
 878                                          "\x0d\x0a", wsi->c_protocol);
 879
 880                 p += sprintf(p, "Sec-WebSocket-Key1: %s\x0d\x0a", key_1);
 881                 p += sprintf(p, "Sec-WebSocket-Key2: %s\x0d\x0a", key_2);
 882
 883                 /* give userland a chance to append, eg, cookies */
 884
 885                 context->protocols[0].callback(context, wsi,
 886                         LWS_CALLBACK_CLIENT_APPEND_HANDSHAKE_HEADER,
 887                                 NULL, &p, (pkt + sizeof(pkt)) - p - 12);
 888
 889                 p += sprintf(p, "\x0d\x0a");
 890
 891                 if (libwebsockets_get_random(context, p, 8) != 8)
 892                         return NULL;
 893                 memcpy(&challenge[8], p, 8);
 894                 p += 8;
 895
 896                 /* precompute what we want to see from the server */
 897
 898                 MD5((unsigned char *)challenge, 16,
 899                    (unsigned char *)wsi->initial_handshake_hash_base64);
 900
 901                 goto issue_hdr;
 902         }
 903
 904         p += sprintf(p, "Host: %s\x0d\x0a", wsi->c_host);
 905         p += sprintf(p, "Upgrade: websocket\x0d\x0a"
 906                                         "Connection: Upgrade\x0d\x0a"
 907                                         "Sec-WebSocket-Key: ");
 908         strcpy(p, wsi->key_b64);
 909         p += strlen(wsi->key_b64);
 910         p += sprintf(p, "\x0d\x0a");
 911         if (wsi->c_origin) {
 912         if (wsi->ietf_spec_revision == 13) {
 913             p += sprintf(p, "Origin: %s\x0d\x0a",
 914                                                          wsi->c_origin);
 915         }
 916         else {
 917                     p += sprintf(p, "Sec-WebSocket-Origin: %s\x0d\x0a",
 918                                                          wsi->c_origin);
 919         }
 920     }
 921         if (wsi->c_protocol)
 922                 p += sprintf(p, "Sec-WebSocket-Protocol: %s\x0d\x0a",
 923                                                        wsi->c_protocol);
 924
 925         /* tell the server what extensions we could support */
 926
 927         p += sprintf(p, "Sec-WebSocket-Extensions: ");
 928
 929         ext = context->extensions;
 930         while (ext && ext->callback) {
 931
 932                 n = 0;
 933                 ext1 = context->extensions;
 934
 935                 while (ext1 && ext1->callback) {
 936                         n |= ext1->callback(context, ext1, wsi,
 937                                 LWS_EXT_CALLBACK_CHECK_OK_TO_PROPOSE_EXTENSION,
 938                                         NULL, (char *)ext->name, 0);
 939
 940                         ext1++;
 941                 }
 942
 943                 if (n) { /* an extension vetos us */
 944                         lwsl_ext("ext %s vetoed\n", (char *)ext->name);
 945                         ext++;
 946                         continue;
 947                 }
 948
 949                 n = context->protocols[0].callback(context, wsi,
 950                         LWS_CALLBACK_CLIENT_CONFIRM_EXTENSION_SUPPORTED,
 951                                 wsi->user_space, (char *)ext->name, 0);
 952
 953                 /*
 954                  * zero return from callback means
 955                  * go ahead and allow the extension,
 956                  * it's what we get if the callback is
 957                  * unhandled
 958                  */
 959
 960                 if (n) {
 961                         ext++;
 962                         continue;
 963                 }
 964
 965                 /* apply it */
 966
 967                 if (ext_count)
 968                         *p++ = ',';
 969                 p += sprintf(p, "%s", ext->name);
 970                 ext_count++;
 971
 972                 ext++;
 973         }
 974
 975         p += sprintf(p, "\x0d\x0a");
 976
 977         if (wsi->ietf_spec_revision)
 978                 p += sprintf(p, "Sec-WebSocket-Version: %d\x0d\x0a",
 979                                                wsi->ietf_spec_revision);
 980
 981         /* give userland a chance to append, eg, cookies */
 982
 983         context->protocols[0].callback(context, wsi,
 984                 LWS_CALLBACK_CLIENT_APPEND_HANDSHAKE_HEADER,
 985                 NULL, &p, (pkt + sizeof(pkt)) - p - 12);
 986
 987         p += sprintf(p, "\x0d\x0a");
 988
 989         /* prepare the expected server accept response */
 990
 991         strcpy((char *)buf, wsi->key_b64);
 992         strcpy((char *)&buf[strlen((char *)buf)], magic_websocket_guid);
 993
 994         SHA1(buf, strlen((char *)buf), (unsigned char *)hash);
 995
 996         lws_b64_encode_string(hash, 20,
 997                         wsi->initial_handshake_hash_base64,
 998                              sizeof wsi->initial_handshake_hash_base64);
 999
1000 issue_hdr:
1001
1002 #if 0
1003         puts(pkt);
1004 #endif
1005
1006         /* done with these now */
1007
1008         free(wsi->c_path);
1009         free(wsi->c_host);
1010         if (wsi->c_origin)
1011                 free(wsi->c_origin);
1012
1013         return p;
1014 }
1015