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 0;
  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 0;
  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 0;
  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 0;
 175                         }
 176                 } else
 177                         wsi->ssl = NULL;
 178         #endif
 179
 180                 p = libwebsockets_generate_client_handshake(context, wsi, p);
 181                 if (p == NULL) {
 182                         lwsl_err("Failed to generate handshake for client, closing it\n");
 183                         libwebsocket_close_and_free_session(context, wsi,
 184                                                      LWS_CLOSE_STATUS_NOSTATUS);
 185                         return 0;
 186                 }
 187
 188                 /* send our request to the server */
 189
 190         #ifdef LWS_OPENSSL_SUPPORT
 191                 if (wsi->use_ssl)
 192                         n = SSL_write(wsi->ssl, pkt, p - pkt);
 193                 else
 194         #endif
 195                         n = send(wsi->sock, pkt, p - pkt, 0);
 196
 197                 if (n < 0) {
 198                         lwsl_debug("ERROR writing to client socket\n");
 199                         libwebsocket_close_and_free_session(context, wsi,
 200                                                      LWS_CLOSE_STATUS_NOSTATUS);
 201                         return 0;
 202                 }
 203
 204                 wsi->parser_state = WSI_TOKEN_NAME_PART;
 205                 wsi->mode = LWS_CONNMODE_WS_CLIENT_WAITING_SERVER_REPLY;
 206                 libwebsocket_set_timeout(wsi,
 207                                 PENDING_TIMEOUT_AWAITING_SERVER_RESPONSE, AWAITING_TIMEOUT);
 208
 209                 break;
 210
 211         case LWS_CONNMODE_WS_CLIENT_WAITING_SERVER_REPLY:
 212
 213                 /* handle server hung up on us */
 214
 215                 if (pollfd->revents & (POLLERR | POLLHUP)) {
 216
 217                         lwsl_debug("Server connection %p (fd=%d) dead\n",
 218                                 (void *)wsi, pollfd->fd);
 219
 220                         goto bail3;
 221                 }
 222
 223
 224                 /* interpret the server response */
 225
 226                 /*
 227                  *  HTTP/1.1 101 Switching Protocols
 228                  *  Upgrade: websocket
 229                  *  Connection: Upgrade
 230                  *  Sec-WebSocket-Accept: me89jWimTRKTWwrS3aRrL53YZSo=
 231                  *  Sec-WebSocket-Nonce: AQIDBAUGBwgJCgsMDQ4PEC==
 232                  *  Sec-WebSocket-Protocol: chat
 233                  */
 234
 235                 /*
 236                  * we have to take some care here to only take from the
 237                  * socket bytewise.  The browser may (and has been seen to
 238                  * in the case that onopen() performs websocket traffic)
 239                  * coalesce both handshake response and websocket traffic
 240                  * in one packet, since at that point the connection is
 241                  * definitively ready from browser pov.
 242                  */
 243
 244                 len = 1;
 245                 while (wsi->parser_state != WSI_PARSING_COMPLETE && len > 0) {
 246 #ifdef LWS_OPENSSL_SUPPORT
 247                         if (wsi->use_ssl)
 248                                 len = SSL_read(wsi->ssl, &c, 1);
 249                          else
 250 #endif
 251                                 len = recv(wsi->sock, &c, 1, 0);
 252
 253                         libwebsocket_parse(wsi, c);
 254                 }
 255
 256                 /*
 257                  * hs may also be coming in multiple packets, there is a 5-sec
 258                  * libwebsocket timeout still active here too, so if parsing did
 259                  * not complete just wait for next packet coming in this state
 260                  */
 261
 262                 if (wsi->parser_state != WSI_PARSING_COMPLETE)
 263                         break;
 264
 265                 /*
 266                  * otherwise deal with the handshake.  If there's any
 267                  * packet traffic already arrived we'll trigger poll() again
 268                  * right away and deal with it that way
 269                  */
 270
 271                 return lws_client_interpret_server_handshake(context, wsi);
 272
 273 bail3:
 274                 if (wsi->c_protocol)
 275                         free(wsi->c_protocol);
 276                 libwebsocket_close_and_free_session(context, wsi,
 277                                                     LWS_CLOSE_STATUS_NOSTATUS);
 278                 return 0;
 279
 280         case LWS_CONNMODE_WS_CLIENT_WAITING_EXTENSION_CONNECT:
 281                 lwsl_ext("LWS_CONNMODE_WS_CLIENT_WAITING_EXTENSION_CONNECT\n");
 282                 break;
 283
 284         case LWS_CONNMODE_WS_CLIENT_PENDING_CANDIDATE_CHILD:
 285                 lwsl_ext("LWS_CONNMODE_WS_CLIENT_PENDING_CANDIDATE_CHILD\n");
 286                 break;
 287         default:
 288                 break;
 289         }
 290
 291         return 0;
 292 }
 293
 294
 295 /*
 296  * In-place str to lower case
 297  */
 298
 299 static void
 300 strtolower(char *s)
 301 {
 302         while (*s) {
 303                 *s = tolower(*s);
 304                 s++;
 305         }
 306 }
 307
 308 int
 309 lws_client_interpret_server_handshake(struct libwebsocket_context *context,
 310                 struct libwebsocket *wsi)
 311 {
 312         unsigned char buf[LWS_SEND_BUFFER_PRE_PADDING + 1 +
 313                         MAX_BROADCAST_PAYLOAD + LWS_SEND_BUFFER_POST_PADDING];
 314         char pkt[1024];
 315         char *p = &pkt[0];
 316         const char *pc;
 317         const char *c;
 318         int more = 1;
 319         int okay = 0;
 320         char ext_name[128];
 321         struct libwebsocket_extension *ext;
 322         void *v;
 323         int len = 0;
 324         int n;
 325         static const char magic_websocket_04_masking_guid[] =
 326                                          "61AC5F19-FBBA-4540-B96F-6561F1AB40A8";
 327
 328         /*
 329          * 00 / 76 -->
 330          *
 331          * HTTP/1.1 101 WebSocket Protocol Handshake
 332          * Upgrade: WebSocket
 333          * Connection: Upgrade
 334          * Sec-WebSocket-Origin: http://127.0.0.1
 335          * Sec-WebSocket-Location: ws://127.0.0.1:9999/socket.io/websocket
 336          *
 337          * xxxxxxxxxxxxxxxx
 338          */
 339
 340         if (wsi->ietf_spec_revision == 0) {
 341                 if (!wsi->utf8_token[WSI_TOKEN_HTTP].token_len ||
 342                         !wsi->utf8_token[WSI_TOKEN_UPGRADE].token_len ||
 343                         !wsi->utf8_token[WSI_TOKEN_CHALLENGE].token_len ||
 344                         !wsi->utf8_token[WSI_TOKEN_CONNECTION].token_len
 345                 ) {
 346                         lwsl_parser("libwebsocket_client_handshake "
 347                                         "missing required header(s)\n");
 348                         pkt[len] = '\0';
 349                         lwsl_parser("%s", pkt);
 350                         goto bail3;
 351                 }
 352
 353                 strtolower(wsi->utf8_token[WSI_TOKEN_HTTP].token);
 354                 if (strncmp(wsi->utf8_token[WSI_TOKEN_HTTP].token, "101", 3)) {
 355                         lwsl_warn("libwebsocket_client_handshake "
 356                                 "server sent bad HTTP response '%s'\n",
 357                                 wsi->utf8_token[WSI_TOKEN_HTTP].token);
 358                         goto bail3;
 359                 }
 360
 361                 if (wsi->utf8_token[WSI_TOKEN_CHALLENGE].token_len < 16) {
 362                         lwsl_parser("libwebsocket_client_handshake "
 363                                 "challenge reply too short %d\n",
 364                                 wsi->utf8_token[
 365                                         WSI_TOKEN_CHALLENGE].token_len);
 366                         pkt[len] = '\0';
 367                         lwsl_parser("%s", pkt);
 368                         goto bail3;
 369
 370                 }
 371
 372                 goto select_protocol;
 373         }
 374
 375         /*
 376          * well, what the server sent looked reasonable for syntax.
 377          * Now let's confirm it sent all the necessary headers
 378          */
 379 #if 0
 380         lwsl_parser("WSI_TOKEN_HTTP: %d\n",
 381                                     wsi->utf8_token[WSI_TOKEN_HTTP].token_len);
 382         lwsl_parser("WSI_TOKEN_UPGRADE: %d\n",
 383                                  wsi->utf8_token[WSI_TOKEN_UPGRADE].token_len);
 384         lwsl_parser("WSI_TOKEN_CONNECTION: %d\n",
 385                               wsi->utf8_token[WSI_TOKEN_CONNECTION].token_len);
 386         lwsl_parser("WSI_TOKEN_ACCEPT: %d\n",
 387                                   wsi->utf8_token[WSI_TOKEN_ACCEPT].token_len);
 388         lwsl_parser("WSI_TOKEN_NONCE: %d\n",
 389                                    wsi->utf8_token[WSI_TOKEN_NONCE].token_len);
 390         lwsl_parser("WSI_TOKEN_PROTOCOL: %d\n",
 391                                 wsi->utf8_token[WSI_TOKEN_PROTOCOL].token_len);
 392 #endif
 393         if (!wsi->utf8_token[WSI_TOKEN_HTTP].token_len ||
 394             !wsi->utf8_token[WSI_TOKEN_UPGRADE].token_len ||
 395             !wsi->utf8_token[WSI_TOKEN_CONNECTION].token_len ||
 396             !wsi->utf8_token[WSI_TOKEN_ACCEPT].token_len ||
 397             (!wsi->utf8_token[WSI_TOKEN_NONCE].token_len &&
 398                                    wsi->ietf_spec_revision == 4)
 399         ) {
 400                 lwsl_parser("libwebsocket_client_handshake "
 401                                         "missing required header(s) revision=%d\n", wsi->ietf_spec_revision);
 402                 pkt[len] = '\0';
 403                 lwsl_parser("%s", pkt);
 404                 goto bail3;
 405         }
 406
 407         /*
 408          * Everything seems to be there, now take a closer look at what
 409          * is in each header
 410          */
 411
 412         strtolower(wsi->utf8_token[WSI_TOKEN_HTTP].token);
 413         if (strncmp(wsi->utf8_token[WSI_TOKEN_HTTP].token, "101", 3)) {
 414                 lwsl_warn("libwebsocket_client_handshake "
 415                                 "server sent bad HTTP response '%s'\n",
 416                                  wsi->utf8_token[WSI_TOKEN_HTTP].token);
 417                 goto bail3;
 418         }
 419
 420         strtolower(wsi->utf8_token[WSI_TOKEN_UPGRADE].token);
 421         if (strcmp(wsi->utf8_token[WSI_TOKEN_UPGRADE].token,
 422                                                          "websocket")) {
 423                 lwsl_warn("libwebsocket_client_handshake server "
 424                                 "sent bad Upgrade header '%s'\n",
 425                                   wsi->utf8_token[WSI_TOKEN_UPGRADE].token);
 426                 goto bail3;
 427         }
 428
 429         strtolower(wsi->utf8_token[WSI_TOKEN_CONNECTION].token);
 430         if (strcmp(wsi->utf8_token[WSI_TOKEN_CONNECTION].token,
 431                                                            "upgrade")) {
 432                 lwsl_warn("libwebsocket_client_handshake server "
 433                                 "sent bad Connection hdr '%s'\n",
 434                            wsi->utf8_token[WSI_TOKEN_CONNECTION].token);
 435                 goto bail3;
 436         }
 437
 438 select_protocol:
 439         pc = wsi->c_protocol;
 440         if (pc == NULL)
 441                 lwsl_parser("lws_client_interpret_server_handshake: "
 442                                                           "NULL c_protocol\n");
 443         else
 444                 lwsl_parser("lws_client_interpret_server_handshake: "
 445                                                       "cPprotocol='%s'\n", pc);
 446
 447         /*
 448          * confirm the protocol the server wants to talk was in the list
 449          * of protocols we offered
 450          */
 451
 452         if (!wsi->utf8_token[WSI_TOKEN_PROTOCOL].token_len) {
 453
 454                 lwsl_info("lws_client_interpret_server_handshake "
 455                                                "WSI_TOKEN_PROTOCOL is null\n");
 456                 /*
 457                  * no protocol name to work from,
 458                  * default to first protocol
 459                  */
 460                 wsi->protocol = &context->protocols[0];
 461                 wsi->c_callback = wsi->protocol->callback;
 462                 free(wsi->c_protocol);
 463
 464                 goto check_extensions;
 465         }
 466
 467         while (*pc && !okay) {
 468                 if ((!strncmp(pc, wsi->utf8_token[WSI_TOKEN_PROTOCOL].token,
 469                  wsi->utf8_token[WSI_TOKEN_PROTOCOL].token_len)) &&
 470                  (pc[wsi->utf8_token[WSI_TOKEN_PROTOCOL].token_len] == ',' ||
 471                   pc[wsi->utf8_token[WSI_TOKEN_PROTOCOL].token_len] == '\0')) {
 472                         okay = 1;
 473                         continue;
 474                 }
 475                 while (*pc && *pc != ',')
 476                         pc++;
 477                 while (*pc && *pc != ' ')
 478                         pc++;
 479         }
 480
 481         /* done with him now */
 482
 483         if (wsi->c_protocol)
 484                 free(wsi->c_protocol);
 485
 486         if (!okay) {
 487                 lwsl_err("libwebsocket_client_handshake server "
 488                                         "sent bad protocol '%s'\n",
 489                                  wsi->utf8_token[WSI_TOKEN_PROTOCOL].token);
 490                 goto bail2;
 491         }
 492
 493         /*
 494          * identify the selected protocol struct and set it
 495          */
 496         n = 0;
 497         wsi->protocol = NULL;
 498         while (context->protocols[n].callback && !wsi->protocol) {  /* Stop after finding first one?? */
 499                 if (strcmp(wsi->utf8_token[WSI_TOKEN_PROTOCOL].token,
 500                                            context->protocols[n].name) == 0) {
 501                         wsi->protocol = &context->protocols[n];
 502                         wsi->c_callback = wsi->protocol->callback;
 503                 }
 504                 n++;
 505         }
 506
 507         if (wsi->protocol == NULL) {
 508                 lwsl_err("libwebsocket_client_handshake server "
 509                                 "requested protocol '%s', which we "
 510                                 "said we supported but we don't!\n",
 511                                  wsi->utf8_token[WSI_TOKEN_PROTOCOL].token);
 512                 goto bail2;
 513         }
 514
 515
 516 check_extensions:
 517
 518         /* instantiate the accepted extensions */
 519
 520         if (!wsi->utf8_token[WSI_TOKEN_EXTENSIONS].token_len) {
 521                 lwsl_ext("no client extenstions allowed by server\n");
 522                 goto check_accept;
 523         }
 524
 525         /*
 526          * break down the list of server accepted extensions
 527          * and go through matching them or identifying bogons
 528          */
 529
 530         c = wsi->utf8_token[WSI_TOKEN_EXTENSIONS].token;
 531         n = 0;
 532         while (more) {
 533
 534                 if (*c && (*c != ',' && *c != ' ' && *c != '\t')) {
 535                         ext_name[n] = *c++;
 536                         if (n < sizeof(ext_name) - 1)
 537                                 n++;
 538                         continue;
 539                 }
 540                 ext_name[n] = '\0';
 541                 if (!*c)
 542                         more = 0;
 543                 else {
 544                         c++;
 545                         if (!n)
 546                                 continue;
 547                 }
 548
 549                 /* check we actually support it */
 550
 551                 lwsl_ext("checking client ext %s\n", ext_name);
 552
 553                 n = 0;
 554                 ext = wsi->protocol->owning_server->extensions;
 555                 while (ext && ext->callback) {
 556
 557                         if (strcmp(ext_name, ext->name)) {
 558                                 ext++;
 559                                 continue;
 560                         }
 561
 562                         n = 1;
 563
 564                         lwsl_ext("instantiating client ext %s\n", ext_name);
 565
 566                         /* instantiate the extension on this conn */
 567
 568                         wsi->active_extensions_user[
 569                                 wsi->count_active_extensions] =
 570                                          malloc(ext->per_session_data_size);
 571                         if (wsi->active_extensions_user[
 572                                 wsi->count_active_extensions] == NULL) {
 573                                 lwsl_err("Out of mem\n");
 574                                 goto bail2;
 575                         }
 576                         memset(wsi->active_extensions_user[
 577                                 wsi->count_active_extensions], 0,
 578                                                     ext->per_session_data_size);
 579                         wsi->active_extensions[
 580                                   wsi->count_active_extensions] = ext;
 581
 582                         /* allow him to construct his context */
 583
 584                         ext->callback(wsi->protocol->owning_server,
 585                                 ext, wsi,
 586                                    LWS_EXT_CALLBACK_CLIENT_CONSTRUCT,
 587                                         wsi->active_extensions_user[
 588                                          wsi->count_active_extensions],
 589                                                                    NULL, 0);
 590
 591                         wsi->count_active_extensions++;
 592
 593                         ext++;
 594                 }
 595
 596                 if (n == 0) {
 597                         lwsl_warn("Server said we should use"
 598                                   "an unknown extension '%s'!\n", ext_name);
 599                         goto bail2;
 600                 }
 601
 602                 n = 0;
 603         }
 604
 605
 606 check_accept:
 607
 608         if (wsi->ietf_spec_revision == 0) {
 609
 610                 if (memcmp(wsi->initial_handshake_hash_base64,
 611                           wsi->utf8_token[WSI_TOKEN_CHALLENGE].token, 16)) {
 612                         lwsl_warn("libwebsocket_client_handshake "
 613                                            "failed 00 challenge compare\n");
 614                                 pkt[len] = '\0';
 615                                 lwsl_warn("%s", pkt);
 616                                 goto bail2;
 617                 }
 618
 619                 goto accept_ok;
 620         }
 621
 622         /*
 623          * Confirm his accept token is the one we precomputed
 624          */
 625
 626         if (strcmp(wsi->utf8_token[WSI_TOKEN_ACCEPT].token,
 627                                   wsi->initial_handshake_hash_base64)) {
 628                 lwsl_warn("libwebsocket_client_handshake server "
 629                         "sent bad ACCEPT '%s' vs computed '%s'\n",
 630                         wsi->utf8_token[WSI_TOKEN_ACCEPT].token,
 631                                         wsi->initial_handshake_hash_base64);
 632                 goto bail2;
 633         }
 634
 635         if (wsi->ietf_spec_revision == 4) {
 636                 /*
 637                  * Calculate the 04 masking key to use when
 638                  * sending data to server
 639                  */
 640
 641                 strcpy((char *)buf, wsi->key_b64);
 642                 p = (char *)buf + strlen(wsi->key_b64);
 643                 strcpy(p, wsi->utf8_token[WSI_TOKEN_NONCE].token);
 644                 p += wsi->utf8_token[WSI_TOKEN_NONCE].token_len;
 645                 strcpy(p, magic_websocket_04_masking_guid);
 646                 SHA1(buf, strlen((char *)buf), wsi->masking_key_04);
 647         }
 648 accept_ok:
 649
 650         /* allocate the per-connection user memory (if any) */
 651         if (wsi->protocol->per_session_data_size &&
 652                                           !libwebsocket_ensure_user_space(wsi))
 653                 goto bail2;
 654
 655         /* clear his proxy connection timeout */
 656
 657         libwebsocket_set_timeout(wsi, NO_PENDING_TIMEOUT, 0);
 658
 659         /* mark him as being alive */
 660
 661         wsi->state = WSI_STATE_ESTABLISHED;
 662         wsi->mode = LWS_CONNMODE_WS_CLIENT;
 663
 664         lwsl_debug("handshake OK for protocol %s\n", wsi->protocol->name);
 665
 666         /* call him back to inform him he is up */
 667
 668         wsi->protocol->callback(context, wsi,
 669                                 LWS_CALLBACK_CLIENT_ESTABLISHED,
 670                                                      wsi->user_space, NULL, 0);
 671
 672         /*
 673          * inform all extensions, not just active ones since they
 674          * already know
 675          */
 676
 677         ext = context->extensions;
 678
 679         while (ext && ext->callback) {
 680                 v = NULL;
 681                 for (n = 0; n < wsi->count_active_extensions; n++)
 682                         if (wsi->active_extensions[n] == ext)
 683                                 v = wsi->active_extensions_user[n];
 684
 685                 ext->callback(context, ext, wsi,
 686                           LWS_EXT_CALLBACK_ANY_WSI_ESTABLISHED, v, NULL, 0);
 687                 ext++;
 688         }
 689
 690         return 0;
 691
 692 bail3:
 693         if (wsi->c_protocol)
 694                 free(wsi->c_protocol);
 695
 696 bail2:
 697         if (wsi->c_callback) wsi->c_callback(context, wsi,
 698        LWS_CALLBACK_CLIENT_CONNECTION_ERROR,
 699                          wsi->user_space,
 700                          NULL, 0);
 701         libwebsocket_close_and_free_session(context, wsi,
 702                                                  LWS_CLOSE_STATUS_NOSTATUS);  // But this should be LWS_CLOSE_STATUS_PROTOCOL_ERR
 703
 704         return 1;
 705 }
 706
 707 void libwebsockets_00_spaceout(char *key, int spaces, int seed)
 708 {
 709         char *p;
 710
 711         key++;
 712         while (spaces--) {
 713                 if (*key && (seed & 1))
 714                         key++;
 715                 seed >>= 1;
 716
 717                 p = key + strlen(key);
 718                 while (p >= key) {
 719                         p[1] = p[0];
 720                         p--;
 721                 }
 722                 *key++ = ' ';
 723         }
 724 }
 725
 726 void libwebsockets_00_spam(char *key, int count, int seed)
 727 {
 728         char *p;
 729
 730         key++;
 731         while (count--) {
 732
 733                 if (*key && (seed & 1))
 734                         key++;
 735                 seed >>= 1;
 736
 737                 p = key + strlen(key);
 738                 while (p >= key) {
 739                         p[1] = p[0];
 740                         p--;
 741                 }
 742                 *key++ = 0x21 + ((seed & 0xffff) % 15);
 743                 /* 4 would use it up too fast.. not like it matters */
 744                 seed >>= 1;
 745         }
 746 }
 747
 748 char *
 749 libwebsockets_generate_client_handshake(struct libwebsocket_context *context,
 750                 struct libwebsocket *wsi, char *pkt)
 751 {
 752         char hash[20];
 753         char *p = pkt;
 754         int n;
 755         struct libwebsocket_extension *ext;
 756         struct libwebsocket_extension *ext1;
 757         int ext_count = 0;
 758         unsigned char buf[LWS_SEND_BUFFER_PRE_PADDING + 1 +
 759                          MAX_BROADCAST_PAYLOAD + LWS_SEND_BUFFER_POST_PADDING];
 760         static const char magic_websocket_guid[] =
 761                                          "258EAFA5-E914-47DA-95CA-C5AB0DC85B11";
 762
 763         /*
 764          * create the random key
 765          */
 766
 767         n = libwebsockets_get_random(context, hash, 16);
 768         if (n != 16) {
 769                 lwsl_err("Unable to read from random dev %s\n",
 770                                                 SYSTEM_RANDOM_FILEPATH);
 771                 free(wsi->c_path);
 772                 free(wsi->c_host);
 773                 if (wsi->c_origin)
 774                         free(wsi->c_origin);
 775                 if (wsi->c_protocol)
 776                         free(wsi->c_protocol);
 777                 libwebsocket_close_and_free_session(context, wsi,
 778                                              LWS_CLOSE_STATUS_NOSTATUS);
 779                 return NULL;
 780         }
 781
 782         lws_b64_encode_string(hash, 16, wsi->key_b64,
 783                                                    sizeof wsi->key_b64);
 784
 785         /*
 786          * 00 example client handshake
 787          *
 788          * GET /socket.io/websocket HTTP/1.1
 789          * Upgrade: WebSocket
 790          * Connection: Upgrade
 791          * Host: 127.0.0.1:9999
 792          * Origin: http://127.0.0.1
 793          * Sec-WebSocket-Key1: 1 0 2#0W 9 89 7  92 ^
 794          * Sec-WebSocket-Key2: 7 7Y 4328 B2v[8(z1
 795          * Cookie: socketio=websocket
 796          *
 797          * (Á®Ä0¶†≥
 798          *
 799          * 04 example client handshake
 800          *
 801          * GET /chat HTTP/1.1
 802          * Host: server.example.com
 803          * Upgrade: websocket
 804          * Connection: Upgrade
 805          * Sec-WebSocket-Key: dGhlIHNhbXBsZSBub25jZQ==
 806          * Sec-WebSocket-Origin: http://example.com
 807          * Sec-WebSocket-Protocol: chat, superchat
 808          * Sec-WebSocket-Version: 4
 809          */
 810
 811         p += sprintf(p, "GET %s HTTP/1.1\x0d\x0a", wsi->c_path);
 812
 813         p += sprintf(p, "Pragma: no-cache\x0d\x0a"
 814                                         "Cache-Control: no-cache\x0d\x0a");
 815
 816         if (wsi->ietf_spec_revision == 0) {
 817                 unsigned char spaces_1, spaces_2;
 818                 unsigned int max_1, max_2;
 819                 unsigned int num_1, num_2;
 820                 unsigned long product_1, product_2;
 821                 char key_1[40];
 822                 char key_2[40];
 823                 unsigned int seed;
 824                 unsigned int count;
 825                 char challenge[16];
 826
 827                 libwebsockets_get_random(context, &spaces_1, sizeof(char));
 828                 libwebsockets_get_random(context, &spaces_2, sizeof(char));
 829
 830                 spaces_1 = (spaces_1 % 12) + 1;
 831                 spaces_2 = (spaces_2 % 12) + 1;
 832
 833                 max_1 = 4294967295 / spaces_1;
 834                 max_2 = 4294967295 / spaces_2;
 835
 836                 libwebsockets_get_random(context, &num_1, sizeof(int));
 837                 libwebsockets_get_random(context, &num_2, sizeof(int));
 838
 839                 num_1 = (num_1 % max_1);
 840                 num_2 = (num_2 % max_2);
 841
 842                 challenge[0] = num_1 >> 24;
 843                 challenge[1] = num_1 >> 16;
 844                 challenge[2] = num_1 >> 8;
 845                 challenge[3] = num_1;
 846                 challenge[4] = num_2 >> 24;
 847                 challenge[5] = num_2 >> 16;
 848                 challenge[6] = num_2 >> 8;
 849                 challenge[7] = num_2;
 850
 851                 product_1 = num_1 * spaces_1;
 852                 product_2 = num_2 * spaces_2;
 853
 854                 sprintf(key_1, "%lu", product_1);
 855                 sprintf(key_2, "%lu", product_2);
 856
 857                 libwebsockets_get_random(context, &seed, sizeof(int));
 858                 libwebsockets_get_random(context, &count, sizeof(int));
 859
 860                 libwebsockets_00_spam(key_1, (count % 12) + 1, seed);
 861
 862                 libwebsockets_get_random(context, &seed, sizeof(int));
 863                 libwebsockets_get_random(context, &count, sizeof(int));
 864
 865                 libwebsockets_00_spam(key_2, (count % 12) + 1, seed);
 866
 867                 libwebsockets_get_random(context, &seed, sizeof(int));
 868
 869                 libwebsockets_00_spaceout(key_1, spaces_1, seed);
 870                 libwebsockets_00_spaceout(key_2, spaces_2, seed >> 16);
 871
 872                 p += sprintf(p, "Upgrade: WebSocket\x0d\x0a"
 873                         "Connection: Upgrade\x0d\x0aHost: %s\x0d\x0a",
 874                         wsi->c_host);
 875                 if (wsi->c_origin)
 876                         p += sprintf(p, "Origin: %s\x0d\x0a", wsi->c_origin);
 877
 878                 if (wsi->c_protocol)
 879                         p += sprintf(p, "Sec-WebSocket-Protocol: %s"
 880                                          "\x0d\x0a", wsi->c_protocol);
 881
 882                 p += sprintf(p, "Sec-WebSocket-Key1: %s\x0d\x0a", key_1);
 883                 p += sprintf(p, "Sec-WebSocket-Key2: %s\x0d\x0a", key_2);
 884
 885                 /* give userland a chance to append, eg, cookies */
 886
 887                 context->protocols[0].callback(context, wsi,
 888                         LWS_CALLBACK_CLIENT_APPEND_HANDSHAKE_HEADER,
 889                                 NULL, &p, (pkt + sizeof(pkt)) - p - 12);
 890
 891                 p += sprintf(p, "\x0d\x0a");
 892
 893                 if (libwebsockets_get_random(context, p, 8) != 8)
 894                         return NULL;
 895                 memcpy(&challenge[8], p, 8);
 896                 p += 8;
 897
 898                 /* precompute what we want to see from the server */
 899
 900                 MD5((unsigned char *)challenge, 16,
 901                    (unsigned char *)wsi->initial_handshake_hash_base64);
 902
 903                 goto issue_hdr;
 904         }
 905
 906         p += sprintf(p, "Host: %s\x0d\x0a", wsi->c_host);
 907         p += sprintf(p, "Upgrade: websocket\x0d\x0a"
 908                                         "Connection: Upgrade\x0d\x0a"
 909                                         "Sec-WebSocket-Key: ");
 910         strcpy(p, wsi->key_b64);
 911         p += strlen(wsi->key_b64);
 912         p += sprintf(p, "\x0d\x0a");
 913         if (wsi->c_origin) {
 914         if (wsi->ietf_spec_revision == 13) {
 915             p += sprintf(p, "Origin: %s\x0d\x0a",
 916                                                          wsi->c_origin);
 917         }
 918         else {
 919                     p += sprintf(p, "Sec-WebSocket-Origin: %s\x0d\x0a",
 920                                                          wsi->c_origin);
 921         }
 922     }
 923         if (wsi->c_protocol)
 924                 p += sprintf(p, "Sec-WebSocket-Protocol: %s\x0d\x0a",
 925                                                        wsi->c_protocol);
 926
 927         /* tell the server what extensions we could support */
 928
 929         p += sprintf(p, "Sec-WebSocket-Extensions: ");
 930
 931         ext = context->extensions;
 932         while (ext && ext->callback) {
 933
 934                 n = 0;
 935                 ext1 = context->extensions;
 936
 937                 while (ext1 && ext1->callback) {
 938                         n |= ext1->callback(context, ext1, wsi,
 939                                 LWS_EXT_CALLBACK_CHECK_OK_TO_PROPOSE_EXTENSION,
 940                                         NULL, (char *)ext->name, 0);
 941
 942                         ext1++;
 943                 }
 944
 945                 if (n) { /* an extension vetos us */
 946                         lwsl_ext("ext %s vetoed\n", (char *)ext->name);
 947                         ext++;
 948                         continue;
 949                 }
 950
 951                 n = context->protocols[0].callback(context, wsi,
 952                         LWS_CALLBACK_CLIENT_CONFIRM_EXTENSION_SUPPORTED,
 953                                 wsi->user_space, (char *)ext->name, 0);
 954
 955                 /*
 956                  * zero return from callback means
 957                  * go ahead and allow the extension,
 958                  * it's what we get if the callback is
 959                  * unhandled
 960                  */
 961
 962                 if (n) {
 963                         ext++;
 964                         continue;
 965                 }
 966
 967                 /* apply it */
 968
 969                 if (ext_count)
 970                         *p++ = ',';
 971                 p += sprintf(p, "%s", ext->name);
 972                 ext_count++;
 973
 974                 ext++;
 975         }
 976
 977         p += sprintf(p, "\x0d\x0a");
 978
 979         if (wsi->ietf_spec_revision)
 980                 p += sprintf(p, "Sec-WebSocket-Version: %d\x0d\x0a",
 981                                                wsi->ietf_spec_revision);
 982
 983         /* give userland a chance to append, eg, cookies */
 984
 985         context->protocols[0].callback(context, wsi,
 986                 LWS_CALLBACK_CLIENT_APPEND_HANDSHAKE_HEADER,
 987                 NULL, &p, (pkt + sizeof(pkt)) - p - 12);
 988
 989         p += sprintf(p, "\x0d\x0a");
 990
 991         /* prepare the expected server accept response */
 992
 993         strcpy((char *)buf, wsi->key_b64);
 994         strcpy((char *)&buf[strlen((char *)buf)], magic_websocket_guid);
 995
 996         SHA1(buf, strlen((char *)buf), (unsigned char *)hash);
 997
 998         lws_b64_encode_string(hash, 20,
 999                         wsi->initial_handshake_hash_base64,
1000                              sizeof wsi->initial_handshake_hash_base64);
1001
1002 issue_hdr:
1003
1004 #if 0
1005         puts(pkt);
1006 #endif
1007
1008         /* done with these now */
1009
1010         free(wsi->c_path);
1011         free(wsi->c_host);
1012         if (wsi->c_origin)
1013                 free(wsi->c_origin);
1014
1015         return p;
1016 }
1017