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->lextable_pos = 0;
 206                 wsi->mode = LWS_CONNMODE_WS_CLIENT_WAITING_SERVER_REPLY;
 207                 libwebsocket_set_timeout(wsi,
 208                                 PENDING_TIMEOUT_AWAITING_SERVER_RESPONSE, AWAITING_TIMEOUT);
 209
 210                 break;
 211
 212         case LWS_CONNMODE_WS_CLIENT_WAITING_SERVER_REPLY:
 213
 214                 /* handle server hung up on us */
 215
 216                 if (pollfd->revents & (POLLERR | POLLHUP)) {
 217
 218                         lwsl_debug("Server connection %p (fd=%d) dead\n",
 219                                 (void *)wsi, pollfd->fd);
 220
 221                         goto bail3;
 222                 }
 223
 224
 225                 /* interpret the server response */
 226
 227                 /*
 228                  *  HTTP/1.1 101 Switching Protocols
 229                  *  Upgrade: websocket
 230                  *  Connection: Upgrade
 231                  *  Sec-WebSocket-Accept: me89jWimTRKTWwrS3aRrL53YZSo=
 232                  *  Sec-WebSocket-Nonce: AQIDBAUGBwgJCgsMDQ4PEC==
 233                  *  Sec-WebSocket-Protocol: chat
 234                  */
 235
 236                 /*
 237                  * we have to take some care here to only take from the
 238                  * socket bytewise.  The browser may (and has been seen to
 239                  * in the case that onopen() performs websocket traffic)
 240                  * coalesce both handshake response and websocket traffic
 241                  * in one packet, since at that point the connection is
 242                  * definitively ready from browser pov.
 243                  */
 244
 245                 len = 1;
 246                 while (wsi->parser_state != WSI_PARSING_COMPLETE && len > 0) {
 247 #ifdef LWS_OPENSSL_SUPPORT
 248                         if (wsi->use_ssl)
 249                                 len = SSL_read(wsi->ssl, &c, 1);
 250                          else
 251 #endif
 252                                 len = recv(wsi->sock, &c, 1, 0);
 253
 254                         libwebsocket_parse(wsi, c);
 255                 }
 256
 257                 /*
 258                  * hs may also be coming in multiple packets, there is a 5-sec
 259                  * libwebsocket timeout still active here too, so if parsing did
 260                  * not complete just wait for next packet coming in this state
 261                  */
 262
 263                 if (wsi->parser_state != WSI_PARSING_COMPLETE)
 264                         break;
 265
 266                 /*
 267                  * otherwise deal with the handshake.  If there's any
 268                  * packet traffic already arrived we'll trigger poll() again
 269                  * right away and deal with it that way
 270                  */
 271
 272                 return lws_client_interpret_server_handshake(context, wsi);
 273
 274 bail3:
 275                 if (wsi->c_protocol)
 276                         free(wsi->c_protocol);
 277                 libwebsocket_close_and_free_session(context, wsi,
 278                                                     LWS_CLOSE_STATUS_NOSTATUS);
 279                 return 0;
 280
 281         case LWS_CONNMODE_WS_CLIENT_WAITING_EXTENSION_CONNECT:
 282                 lwsl_ext("LWS_CONNMODE_WS_CLIENT_WAITING_EXTENSION_CONNECT\n");
 283                 break;
 284
 285         case LWS_CONNMODE_WS_CLIENT_PENDING_CANDIDATE_CHILD:
 286                 lwsl_ext("LWS_CONNMODE_WS_CLIENT_PENDING_CANDIDATE_CHILD\n");
 287                 break;
 288         default:
 289                 break;
 290         }
 291
 292         return 0;
 293 }
 294
 295
 296 /*
 297  * In-place str to lower case
 298  */
 299
 300 static void
 301 strtolower(char *s)
 302 {
 303         while (*s) {
 304                 *s = tolower(*s);
 305                 s++;
 306         }
 307 }
 308
 309 int
 310 lws_client_interpret_server_handshake(struct libwebsocket_context *context,
 311                 struct libwebsocket *wsi)
 312 {
 313         unsigned char buf[LWS_SEND_BUFFER_PRE_PADDING + 1 +
 314                         MAX_BROADCAST_PAYLOAD + LWS_SEND_BUFFER_POST_PADDING];
 315         char pkt[1024];
 316         char *p = &pkt[0];
 317         const char *pc;
 318         int okay = 0;
 319 #ifndef LWS_NO_EXTENSIONS
 320         char ext_name[128];
 321         struct libwebsocket_extension *ext;
 322         void *v;
 323         int more = 1;
 324         const char *c;
 325 #endif
 326         int len = 0;
 327         int n;
 328         static const char magic_websocket_04_masking_guid[] =
 329                                          "61AC5F19-FBBA-4540-B96F-6561F1AB40A8";
 330
 331         /*
 332          * 00 / 76 -->
 333          *
 334          * HTTP/1.1 101 WebSocket Protocol Handshake
 335          * Upgrade: WebSocket
 336          * Connection: Upgrade
 337          * Sec-WebSocket-Origin: http://127.0.0.1
 338          * Sec-WebSocket-Location: ws://127.0.0.1:9999/socket.io/websocket
 339          *
 340          * xxxxxxxxxxxxxxxx
 341          */
 342
 343         if (wsi->ietf_spec_revision == 0) {
 344                 if (!wsi->utf8_token[WSI_TOKEN_HTTP].token_len ||
 345                         !wsi->utf8_token[WSI_TOKEN_UPGRADE].token_len ||
 346                         !wsi->utf8_token[WSI_TOKEN_CHALLENGE].token_len ||
 347                         !wsi->utf8_token[WSI_TOKEN_CONNECTION].token_len
 348                 ) {
 349                         lwsl_parser("libwebsocket_client_handshake "
 350                                         "missing required header(s)\n");
 351                         pkt[len] = '\0';
 352                         lwsl_parser("%s", pkt);
 353                         goto bail3;
 354                 }
 355
 356                 strtolower(wsi->utf8_token[WSI_TOKEN_HTTP].token);
 357                 if (strncmp(wsi->utf8_token[WSI_TOKEN_HTTP].token, "101", 3)) {
 358                         lwsl_warn("libwebsocket_client_handshake "
 359                                 "server sent bad HTTP response '%s'\n",
 360                                 wsi->utf8_token[WSI_TOKEN_HTTP].token);
 361                         goto bail3;
 362                 }
 363
 364                 if (wsi->utf8_token[WSI_TOKEN_CHALLENGE].token_len < 16) {
 365                         lwsl_parser("libwebsocket_client_handshake "
 366                                 "challenge reply too short %d\n",
 367                                 wsi->utf8_token[
 368                                         WSI_TOKEN_CHALLENGE].token_len);
 369                         pkt[len] = '\0';
 370                         lwsl_parser("%s", pkt);
 371                         goto bail3;
 372
 373                 }
 374
 375                 goto select_protocol;
 376         }
 377
 378         /*
 379          * well, what the server sent looked reasonable for syntax.
 380          * Now let's confirm it sent all the necessary headers
 381          */
 382 #if 0
 383         lwsl_parser("WSI_TOKEN_HTTP: %d\n",
 384                                     wsi->utf8_token[WSI_TOKEN_HTTP].token_len);
 385         lwsl_parser("WSI_TOKEN_UPGRADE: %d\n",
 386                                  wsi->utf8_token[WSI_TOKEN_UPGRADE].token_len);
 387         lwsl_parser("WSI_TOKEN_CONNECTION: %d\n",
 388                               wsi->utf8_token[WSI_TOKEN_CONNECTION].token_len);
 389         lwsl_parser("WSI_TOKEN_ACCEPT: %d\n",
 390                                   wsi->utf8_token[WSI_TOKEN_ACCEPT].token_len);
 391         lwsl_parser("WSI_TOKEN_NONCE: %d\n",
 392                                    wsi->utf8_token[WSI_TOKEN_NONCE].token_len);
 393         lwsl_parser("WSI_TOKEN_PROTOCOL: %d\n",
 394                                 wsi->utf8_token[WSI_TOKEN_PROTOCOL].token_len);
 395 #endif
 396         if (!wsi->utf8_token[WSI_TOKEN_HTTP].token_len ||
 397             !wsi->utf8_token[WSI_TOKEN_UPGRADE].token_len ||
 398             !wsi->utf8_token[WSI_TOKEN_CONNECTION].token_len ||
 399             !wsi->utf8_token[WSI_TOKEN_ACCEPT].token_len ||
 400             (!wsi->utf8_token[WSI_TOKEN_NONCE].token_len &&
 401                                    wsi->ietf_spec_revision == 4)
 402         ) {
 403                 lwsl_parser("libwebsocket_client_handshake "
 404                                         "missing required header(s) revision=%d\n", wsi->ietf_spec_revision);
 405                 pkt[len] = '\0';
 406                 lwsl_parser("%s", pkt);
 407                 goto bail3;
 408         }
 409
 410         /*
 411          * Everything seems to be there, now take a closer look at what
 412          * is in each header
 413          */
 414
 415         strtolower(wsi->utf8_token[WSI_TOKEN_HTTP].token);
 416         if (strncmp(wsi->utf8_token[WSI_TOKEN_HTTP].token, "101", 3)) {
 417                 lwsl_warn("libwebsocket_client_handshake "
 418                                 "server sent bad HTTP response '%s'\n",
 419                                  wsi->utf8_token[WSI_TOKEN_HTTP].token);
 420                 goto bail3;
 421         }
 422
 423         strtolower(wsi->utf8_token[WSI_TOKEN_UPGRADE].token);
 424         if (strcmp(wsi->utf8_token[WSI_TOKEN_UPGRADE].token,
 425                                                          "websocket")) {
 426                 lwsl_warn("libwebsocket_client_handshake server "
 427                                 "sent bad Upgrade header '%s'\n",
 428                                   wsi->utf8_token[WSI_TOKEN_UPGRADE].token);
 429                 goto bail3;
 430         }
 431
 432         strtolower(wsi->utf8_token[WSI_TOKEN_CONNECTION].token);
 433         if (strcmp(wsi->utf8_token[WSI_TOKEN_CONNECTION].token,
 434                                                            "upgrade")) {
 435                 lwsl_warn("libwebsocket_client_handshake server "
 436                                 "sent bad Connection hdr '%s'\n",
 437                            wsi->utf8_token[WSI_TOKEN_CONNECTION].token);
 438                 goto bail3;
 439         }
 440
 441 select_protocol:
 442         pc = wsi->c_protocol;
 443         if (pc == NULL)
 444                 lwsl_parser("lws_client_interpret_server_handshake: "
 445                                                           "NULL c_protocol\n");
 446         else
 447                 lwsl_parser("lws_client_interpret_server_handshake: "
 448                                                       "cPprotocol='%s'\n", pc);
 449
 450         /*
 451          * confirm the protocol the server wants to talk was in the list
 452          * of protocols we offered
 453          */
 454
 455         if (!wsi->utf8_token[WSI_TOKEN_PROTOCOL].token_len) {
 456
 457                 lwsl_info("lws_client_interpret_server_handshake "
 458                                                "WSI_TOKEN_PROTOCOL is null\n");
 459                 /*
 460                  * no protocol name to work from,
 461                  * default to first protocol
 462                  */
 463                 wsi->protocol = &context->protocols[0];
 464                 wsi->c_callback = wsi->protocol->callback;
 465                 free(wsi->c_protocol);
 466
 467                 goto check_extensions;
 468         }
 469
 470         while (*pc && !okay) {
 471                 if ((!strncmp(pc, wsi->utf8_token[WSI_TOKEN_PROTOCOL].token,
 472                  wsi->utf8_token[WSI_TOKEN_PROTOCOL].token_len)) &&
 473                  (pc[wsi->utf8_token[WSI_TOKEN_PROTOCOL].token_len] == ',' ||
 474                   pc[wsi->utf8_token[WSI_TOKEN_PROTOCOL].token_len] == '\0')) {
 475                         okay = 1;
 476                         continue;
 477                 }
 478                 while (*pc && *pc != ',')
 479                         pc++;
 480                 while (*pc && *pc != ' ')
 481                         pc++;
 482         }
 483
 484         /* done with him now */
 485
 486         if (wsi->c_protocol)
 487                 free(wsi->c_protocol);
 488
 489         if (!okay) {
 490                 lwsl_err("libwebsocket_client_handshake server "
 491                                         "sent bad protocol '%s'\n",
 492                                  wsi->utf8_token[WSI_TOKEN_PROTOCOL].token);
 493                 goto bail2;
 494         }
 495
 496         /*
 497          * identify the selected protocol struct and set it
 498          */
 499         n = 0;
 500         wsi->protocol = NULL;
 501         while (context->protocols[n].callback && !wsi->protocol) {  /* Stop after finding first one?? */
 502                 if (strcmp(wsi->utf8_token[WSI_TOKEN_PROTOCOL].token,
 503                                            context->protocols[n].name) == 0) {
 504                         wsi->protocol = &context->protocols[n];
 505                         wsi->c_callback = wsi->protocol->callback;
 506                 }
 507                 n++;
 508         }
 509
 510         if (wsi->protocol == NULL) {
 511                 lwsl_err("libwebsocket_client_handshake server "
 512                                 "requested protocol '%s', which we "
 513                                 "said we supported but we don't!\n",
 514                                  wsi->utf8_token[WSI_TOKEN_PROTOCOL].token);
 515                 goto bail2;
 516         }
 517
 518
 519 check_extensions:
 520 #ifndef LWS_NO_EXTENSIONS
 521         /* instantiate the accepted extensions */
 522
 523         if (!wsi->utf8_token[WSI_TOKEN_EXTENSIONS].token_len) {
 524                 lwsl_ext("no client extenstions allowed by server\n");
 525                 goto check_accept;
 526         }
 527
 528         /*
 529          * break down the list of server accepted extensions
 530          * and go through matching them or identifying bogons
 531          */
 532
 533         c = wsi->utf8_token[WSI_TOKEN_EXTENSIONS].token;
 534         n = 0;
 535         while (more) {
 536
 537                 if (*c && (*c != ',' && *c != ' ' && *c != '\t')) {
 538                         ext_name[n] = *c++;
 539                         if (n < sizeof(ext_name) - 1)
 540                                 n++;
 541                         continue;
 542                 }
 543                 ext_name[n] = '\0';
 544                 if (!*c)
 545                         more = 0;
 546                 else {
 547                         c++;
 548                         if (!n)
 549                                 continue;
 550                 }
 551
 552                 /* check we actually support it */
 553
 554                 lwsl_ext("checking client ext %s\n", ext_name);
 555
 556                 n = 0;
 557                 ext = wsi->protocol->owning_server->extensions;
 558                 while (ext && ext->callback) {
 559
 560                         if (strcmp(ext_name, ext->name)) {
 561                                 ext++;
 562                                 continue;
 563                         }
 564
 565                         n = 1;
 566
 567                         lwsl_ext("instantiating client ext %s\n", ext_name);
 568
 569                         /* instantiate the extension on this conn */
 570
 571                         wsi->active_extensions_user[
 572                                 wsi->count_active_extensions] =
 573                                          malloc(ext->per_session_data_size);
 574                         if (wsi->active_extensions_user[
 575                                 wsi->count_active_extensions] == NULL) {
 576                                 lwsl_err("Out of mem\n");
 577                                 goto bail2;
 578                         }
 579                         memset(wsi->active_extensions_user[
 580                                 wsi->count_active_extensions], 0,
 581                                                     ext->per_session_data_size);
 582                         wsi->active_extensions[
 583                                   wsi->count_active_extensions] = ext;
 584
 585                         /* allow him to construct his context */
 586
 587                         ext->callback(wsi->protocol->owning_server,
 588                                 ext, wsi,
 589                                    LWS_EXT_CALLBACK_CLIENT_CONSTRUCT,
 590                                         wsi->active_extensions_user[
 591                                          wsi->count_active_extensions],
 592                                                                    NULL, 0);
 593
 594                         wsi->count_active_extensions++;
 595
 596                         ext++;
 597                 }
 598
 599                 if (n == 0) {
 600                         lwsl_warn("Server said we should use"
 601                                   "an unknown extension '%s'!\n", ext_name);
 602                         goto bail2;
 603                 }
 604
 605                 n = 0;
 606         }
 607
 608 check_accept:
 609 #endif
 610
 611         if (wsi->ietf_spec_revision == 0) {
 612
 613                 if (memcmp(wsi->initial_handshake_hash_base64,
 614                           wsi->utf8_token[WSI_TOKEN_CHALLENGE].token, 16)) {
 615                         lwsl_warn("libwebsocket_client_handshake "
 616                                            "failed 00 challenge compare\n");
 617                                 pkt[len] = '\0';
 618                                 lwsl_warn("%s", pkt);
 619                                 goto bail2;
 620                 }
 621
 622                 goto accept_ok;
 623         }
 624
 625         /*
 626          * Confirm his accept token is the one we precomputed
 627          */
 628
 629         if (strcmp(wsi->utf8_token[WSI_TOKEN_ACCEPT].token,
 630                                   wsi->initial_handshake_hash_base64)) {
 631                 lwsl_warn("libwebsocket_client_handshake server "
 632                         "sent bad ACCEPT '%s' vs computed '%s'\n",
 633                         wsi->utf8_token[WSI_TOKEN_ACCEPT].token,
 634                                         wsi->initial_handshake_hash_base64);
 635                 goto bail2;
 636         }
 637
 638         if (wsi->ietf_spec_revision == 4) {
 639                 /*
 640                  * Calculate the 04 masking key to use when
 641                  * sending data to server
 642                  */
 643
 644                 strcpy((char *)buf, wsi->key_b64);
 645                 p = (char *)buf + strlen(wsi->key_b64);
 646                 strcpy(p, wsi->utf8_token[WSI_TOKEN_NONCE].token);
 647                 p += wsi->utf8_token[WSI_TOKEN_NONCE].token_len;
 648                 strcpy(p, magic_websocket_04_masking_guid);
 649                 SHA1(buf, strlen((char *)buf), wsi->masking_key_04);
 650         }
 651 accept_ok:
 652
 653         /* allocate the per-connection user memory (if any) */
 654         if (wsi->protocol->per_session_data_size &&
 655                                           !libwebsocket_ensure_user_space(wsi))
 656                 goto bail2;
 657
 658         /* clear his proxy connection timeout */
 659
 660         libwebsocket_set_timeout(wsi, NO_PENDING_TIMEOUT, 0);
 661
 662         /* mark him as being alive */
 663
 664         wsi->state = WSI_STATE_ESTABLISHED;
 665         wsi->mode = LWS_CONNMODE_WS_CLIENT;
 666
 667         lwsl_debug("handshake OK for protocol %s\n", wsi->protocol->name);
 668
 669         /* call him back to inform him he is up */
 670
 671         wsi->protocol->callback(context, wsi,
 672                                 LWS_CALLBACK_CLIENT_ESTABLISHED,
 673                                                      wsi->user_space, NULL, 0);
 674 #ifndef LWS_NO_EXTENSIONS
 675         /*
 676          * inform all extensions, not just active ones since they
 677          * already know
 678          */
 679
 680         ext = context->extensions;
 681
 682         while (ext && ext->callback) {
 683                 v = NULL;
 684                 for (n = 0; n < wsi->count_active_extensions; n++)
 685                         if (wsi->active_extensions[n] == ext)
 686                                 v = wsi->active_extensions_user[n];
 687
 688                 ext->callback(context, ext, wsi,
 689                           LWS_EXT_CALLBACK_ANY_WSI_ESTABLISHED, v, NULL, 0);
 690                 ext++;
 691         }
 692 #endif
 693
 694         return 0;
 695
 696 bail3:
 697         if (wsi->c_protocol)
 698                 free(wsi->c_protocol);
 699
 700 bail2:
 701         if (wsi->c_callback) wsi->c_callback(context, wsi,
 702        LWS_CALLBACK_CLIENT_CONNECTION_ERROR,
 703                          wsi->user_space,
 704                          NULL, 0);
 705         libwebsocket_close_and_free_session(context, wsi,
 706                                                  LWS_CLOSE_STATUS_NOSTATUS);  // But this should be LWS_CLOSE_STATUS_PROTOCOL_ERR
 707
 708         return 1;
 709 }
 710
 711 void libwebsockets_00_spaceout(char *key, int spaces, int seed)
 712 {
 713         char *p;
 714
 715         key++;
 716         while (spaces--) {
 717                 if (*key && (seed & 1))
 718                         key++;
 719                 seed >>= 1;
 720
 721                 p = key + strlen(key);
 722                 while (p >= key) {
 723                         p[1] = p[0];
 724                         p--;
 725                 }
 726                 *key++ = ' ';
 727         }
 728 }
 729
 730 void libwebsockets_00_spam(char *key, int count, int seed)
 731 {
 732         char *p;
 733
 734         key++;
 735         while (count--) {
 736
 737                 if (*key && (seed & 1))
 738                         key++;
 739                 seed >>= 1;
 740
 741                 p = key + strlen(key);
 742                 while (p >= key) {
 743                         p[1] = p[0];
 744                         p--;
 745                 }
 746                 *key++ = 0x21 + ((seed & 0xffff) % 15);
 747                 /* 4 would use it up too fast.. not like it matters */
 748                 seed >>= 1;
 749         }
 750 }
 751
 752 char *
 753 libwebsockets_generate_client_handshake(struct libwebsocket_context *context,
 754                 struct libwebsocket *wsi, char *pkt)
 755 {
 756         char hash[20];
 757         char *p = pkt;
 758         int n;
 759 #ifndef LWS_NO_EXTENSIONS
 760         struct libwebsocket_extension *ext;
 761         struct libwebsocket_extension *ext1;
 762         int ext_count = 0;
 763 #endif
 764         unsigned char buf[LWS_SEND_BUFFER_PRE_PADDING + 1 +
 765                          MAX_BROADCAST_PAYLOAD + LWS_SEND_BUFFER_POST_PADDING];
 766         static const char magic_websocket_guid[] =
 767                                          "258EAFA5-E914-47DA-95CA-C5AB0DC85B11";
 768
 769         /*
 770          * create the random key
 771          */
 772
 773         n = libwebsockets_get_random(context, hash, 16);
 774         if (n != 16) {
 775                 lwsl_err("Unable to read from random dev %s\n",
 776                                                 SYSTEM_RANDOM_FILEPATH);
 777                 free(wsi->c_path);
 778                 free(wsi->c_host);
 779                 if (wsi->c_origin)
 780                         free(wsi->c_origin);
 781                 if (wsi->c_protocol)
 782                         free(wsi->c_protocol);
 783                 libwebsocket_close_and_free_session(context, wsi,
 784                                              LWS_CLOSE_STATUS_NOSTATUS);
 785                 return NULL;
 786         }
 787
 788         lws_b64_encode_string(hash, 16, wsi->key_b64,
 789                                                    sizeof wsi->key_b64);
 790
 791         /*
 792          * 00 example client handshake
 793          *
 794          * GET /socket.io/websocket HTTP/1.1
 795          * Upgrade: WebSocket
 796          * Connection: Upgrade
 797          * Host: 127.0.0.1:9999
 798          * Origin: http://127.0.0.1
 799          * Sec-WebSocket-Key1: 1 0 2#0W 9 89 7  92 ^
 800          * Sec-WebSocket-Key2: 7 7Y 4328 B2v[8(z1
 801          * Cookie: socketio=websocket
 802          *
 803          * (Á®Ä0¶†≥
 804          *
 805          * 04 example client handshake
 806          *
 807          * GET /chat HTTP/1.1
 808          * Host: server.example.com
 809          * Upgrade: websocket
 810          * Connection: Upgrade
 811          * Sec-WebSocket-Key: dGhlIHNhbXBsZSBub25jZQ==
 812          * Sec-WebSocket-Origin: http://example.com
 813          * Sec-WebSocket-Protocol: chat, superchat
 814          * Sec-WebSocket-Version: 4
 815          */
 816
 817         p += sprintf(p, "GET %s HTTP/1.1\x0d\x0a", wsi->c_path);
 818
 819         p += sprintf(p, "Pragma: no-cache\x0d\x0a"
 820                                         "Cache-Control: no-cache\x0d\x0a");
 821
 822         if (wsi->ietf_spec_revision == 0) {
 823                 unsigned char spaces_1, spaces_2;
 824                 unsigned int max_1, max_2;
 825                 unsigned int num_1, num_2;
 826                 unsigned long product_1, product_2;
 827                 char key_1[40];
 828                 char key_2[40];
 829                 unsigned int seed;
 830                 unsigned int count;
 831                 char challenge[16];
 832
 833                 libwebsockets_get_random(context, &spaces_1, sizeof(char));
 834                 libwebsockets_get_random(context, &spaces_2, sizeof(char));
 835
 836                 spaces_1 = (spaces_1 % 12) + 1;
 837                 spaces_2 = (spaces_2 % 12) + 1;
 838
 839                 max_1 = 4294967295 / spaces_1;
 840                 max_2 = 4294967295 / spaces_2;
 841
 842                 libwebsockets_get_random(context, &num_1, sizeof(int));
 843                 libwebsockets_get_random(context, &num_2, sizeof(int));
 844
 845                 num_1 = (num_1 % max_1);
 846                 num_2 = (num_2 % max_2);
 847
 848                 challenge[0] = num_1 >> 24;
 849                 challenge[1] = num_1 >> 16;
 850                 challenge[2] = num_1 >> 8;
 851                 challenge[3] = num_1;
 852                 challenge[4] = num_2 >> 24;
 853                 challenge[5] = num_2 >> 16;
 854                 challenge[6] = num_2 >> 8;
 855                 challenge[7] = num_2;
 856
 857                 product_1 = num_1 * spaces_1;
 858                 product_2 = num_2 * spaces_2;
 859
 860                 sprintf(key_1, "%lu", product_1);
 861                 sprintf(key_2, "%lu", product_2);
 862
 863                 libwebsockets_get_random(context, &seed, sizeof(int));
 864                 libwebsockets_get_random(context, &count, sizeof(int));
 865
 866                 libwebsockets_00_spam(key_1, (count % 12) + 1, seed);
 867
 868                 libwebsockets_get_random(context, &seed, sizeof(int));
 869                 libwebsockets_get_random(context, &count, sizeof(int));
 870
 871                 libwebsockets_00_spam(key_2, (count % 12) + 1, seed);
 872
 873                 libwebsockets_get_random(context, &seed, sizeof(int));
 874
 875                 libwebsockets_00_spaceout(key_1, spaces_1, seed);
 876                 libwebsockets_00_spaceout(key_2, spaces_2, seed >> 16);
 877
 878                 p += sprintf(p, "Upgrade: WebSocket\x0d\x0a"
 879                         "Connection: Upgrade\x0d\x0aHost: %s\x0d\x0a",
 880                         wsi->c_host);
 881                 if (wsi->c_origin)
 882                         p += sprintf(p, "Origin: %s\x0d\x0a", wsi->c_origin);
 883
 884                 if (wsi->c_protocol)
 885                         p += sprintf(p, "Sec-WebSocket-Protocol: %s"
 886                                          "\x0d\x0a", wsi->c_protocol);
 887
 888                 p += sprintf(p, "Sec-WebSocket-Key1: %s\x0d\x0a", key_1);
 889                 p += sprintf(p, "Sec-WebSocket-Key2: %s\x0d\x0a", key_2);
 890
 891                 /* give userland a chance to append, eg, cookies */
 892
 893                 context->protocols[0].callback(context, wsi,
 894                         LWS_CALLBACK_CLIENT_APPEND_HANDSHAKE_HEADER,
 895                                 NULL, &p, (pkt + sizeof(pkt)) - p - 12);
 896
 897                 p += sprintf(p, "\x0d\x0a");
 898
 899                 if (libwebsockets_get_random(context, p, 8) != 8)
 900                         return NULL;
 901                 memcpy(&challenge[8], p, 8);
 902                 p += 8;
 903
 904                 /* precompute what we want to see from the server */
 905
 906                 MD5((unsigned char *)challenge, 16,
 907                    (unsigned char *)wsi->initial_handshake_hash_base64);
 908
 909                 goto issue_hdr;
 910         }
 911
 912         p += sprintf(p, "Host: %s\x0d\x0a", wsi->c_host);
 913         p += sprintf(p, "Upgrade: websocket\x0d\x0a"
 914                                         "Connection: Upgrade\x0d\x0a"
 915                                         "Sec-WebSocket-Key: ");
 916         strcpy(p, wsi->key_b64);
 917         p += strlen(wsi->key_b64);
 918         p += sprintf(p, "\x0d\x0a");
 919         if (wsi->c_origin) {
 920         if (wsi->ietf_spec_revision == 13) {
 921             p += sprintf(p, "Origin: %s\x0d\x0a",
 922                                                          wsi->c_origin);
 923         }
 924         else {
 925                     p += sprintf(p, "Sec-WebSocket-Origin: %s\x0d\x0a",
 926                                                          wsi->c_origin);
 927         }
 928     }
 929         if (wsi->c_protocol)
 930                 p += sprintf(p, "Sec-WebSocket-Protocol: %s\x0d\x0a",
 931                                                        wsi->c_protocol);
 932
 933         /* tell the server what extensions we could support */
 934
 935         p += sprintf(p, "Sec-WebSocket-Extensions: ");
 936 #ifndef LWS_NO_EXTENSIONS
 937         ext = context->extensions;
 938         while (ext && ext->callback) {
 939
 940                 n = 0;
 941                 ext1 = context->extensions;
 942
 943                 while (ext1 && ext1->callback) {
 944                         n |= ext1->callback(context, ext1, wsi,
 945                                 LWS_EXT_CALLBACK_CHECK_OK_TO_PROPOSE_EXTENSION,
 946                                         NULL, (char *)ext->name, 0);
 947
 948                         ext1++;
 949                 }
 950
 951                 if (n) { /* an extension vetos us */
 952                         lwsl_ext("ext %s vetoed\n", (char *)ext->name);
 953                         ext++;
 954                         continue;
 955                 }
 956
 957                 n = context->protocols[0].callback(context, wsi,
 958                         LWS_CALLBACK_CLIENT_CONFIRM_EXTENSION_SUPPORTED,
 959                                 wsi->user_space, (char *)ext->name, 0);
 960
 961                 /*
 962                  * zero return from callback means
 963                  * go ahead and allow the extension,
 964                  * it's what we get if the callback is
 965                  * unhandled
 966                  */
 967
 968                 if (n) {
 969                         ext++;
 970                         continue;
 971                 }
 972
 973                 /* apply it */
 974
 975                 if (ext_count)
 976                         *p++ = ',';
 977                 p += sprintf(p, "%s", ext->name);
 978                 ext_count++;
 979
 980                 ext++;
 981         }
 982 #endif
 983         p += sprintf(p, "\x0d\x0a");
 984
 985         if (wsi->ietf_spec_revision)
 986                 p += sprintf(p, "Sec-WebSocket-Version: %d\x0d\x0a",
 987                                                wsi->ietf_spec_revision);
 988
 989         /* give userland a chance to append, eg, cookies */
 990
 991         context->protocols[0].callback(context, wsi,
 992                 LWS_CALLBACK_CLIENT_APPEND_HANDSHAKE_HEADER,
 993                 NULL, &p, (pkt + sizeof(pkt)) - p - 12);
 994
 995         p += sprintf(p, "\x0d\x0a");
 996
 997         /* prepare the expected server accept response */
 998
 999         strcpy((char *)buf, wsi->key_b64);
1000         strcpy((char *)&buf[strlen((char *)buf)], magic_websocket_guid);
1001
1002         SHA1(buf, strlen((char *)buf), (unsigned char *)hash);
1003
1004         lws_b64_encode_string(hash, 20,
1005                         wsi->initial_handshake_hash_base64,
1006                              sizeof wsi->initial_handshake_hash_base64);
1007
1008 issue_hdr:
1009
1010 #if 0
1011         puts(pkt);
1012 #endif
1013
1014         /* done with these now */
1015
1016         free(wsi->c_path);
1017         free(wsi->c_host);
1018         if (wsi->c_origin)
1019                 free(wsi->c_origin);
1020
1021         return p;
1022 }
1023