1 /*************************************************************************** 2 * _ _ ____ _ 3 * Project ___| | | | _ \| | 4 * / __| | | | |_) | | 5 * | (__| |_| | _ <| |___ 6 * \___|\___/|_| \_\_____| 7 * 8 * Copyright (C) 1998 - 2016, Daniel Stenberg, <daniel (at) haxx.se>, et al. 9 * 10 * This software is licensed as described in the file COPYING, which 11 * you should have received as part of this distribution. The terms 12 * are also available at https://curl.haxx.se/docs/copyright.html. 13 * 14 * You may opt to use, copy, modify, merge, publish, distribute and/or sell 15 * copies of the Software, and permit persons to whom the Software is 16 * furnished to do so, under the terms of the COPYING file. 17 * 18 * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY 19 * KIND, either express or implied. 20 * 21 ***************************************************************************/ 22 23 #include "curl_setup.h" 24 25 #if !defined(CURL_DISABLE_PROXY) 26 27 #ifdef HAVE_NETINET_IN_H 28 #include <netinet/in.h> 29 #endif 30 #ifdef HAVE_ARPA_INET_H 31 #include <arpa/inet.h> 32 #endif 33 34 #include "urldata.h" 35 #include "sendf.h" 36 #include "select.h" 37 #include "connect.h" 38 #include "timeval.h" 39 #include "socks.h" 40 41 /* The last #include file should be: */ 42 #include "memdebug.h" 43 44 /* 45 * Helper read-from-socket functions. Does the same as Curl_read() but it 46 * blocks until all bytes amount of buffersize will be read. No more, no less. 47 * 48 * This is STUPID BLOCKING behaviour which we frown upon, but right now this 49 * is what we have... 50 */ 51 int Curl_blockread_all(struct connectdata *conn, /* connection data */ 52 curl_socket_t sockfd, /* read from this socket */ 53 char *buf, /* store read data here */ 54 ssize_t buffersize, /* max amount to read */ 55 ssize_t *n) /* amount bytes read */ 56 { 57 ssize_t nread; 58 ssize_t allread = 0; 59 int result; 60 time_t timeleft; 61 *n = 0; 62 for(;;) { 63 timeleft = Curl_timeleft(conn->data, NULL, TRUE); 64 if(timeleft < 0) { 65 /* we already got the timeout */ 66 result = CURLE_OPERATION_TIMEDOUT; 67 break; 68 } 69 if(SOCKET_READABLE(sockfd, timeleft) <= 0) { 70 result = ~CURLE_OK; 71 break; 72 } 73 result = Curl_read_plain(sockfd, buf, buffersize, &nread); 74 if(CURLE_AGAIN == result) 75 continue; 76 else if(result) 77 break; 78 79 if(buffersize == nread) { 80 allread += nread; 81 *n = allread; 82 result = CURLE_OK; 83 break; 84 } 85 if(!nread) { 86 result = ~CURLE_OK; 87 break; 88 } 89 90 buffersize -= nread; 91 buf += nread; 92 allread += nread; 93 } 94 return result; 95 } 96 97 /* 98 * This function logs in to a SOCKS4 proxy and sends the specifics to the final 99 * destination server. 100 * 101 * Reference : 102 * http://socks.permeo.com/protocol/socks4.protocol 103 * 104 * Note : 105 * Set protocol4a=true for "SOCKS 4A (Simple Extension to SOCKS 4 Protocol)" 106 * Nonsupport "Identification Protocol (RFC1413)" 107 */ 108 CURLcode Curl_SOCKS4(const char *proxy_name, 109 const char *hostname, 110 int remote_port, 111 int sockindex, 112 struct connectdata *conn) 113 { 114 const bool protocol4a = 115 (conn->socks_proxy.proxytype == CURLPROXY_SOCKS4A) ? TRUE : FALSE; 116 #define SOCKS4REQLEN 262 117 unsigned char socksreq[SOCKS4REQLEN]; /* room for SOCKS4 request incl. user 118 id */ 119 int result; 120 CURLcode code; 121 curl_socket_t sock = conn->sock[sockindex]; 122 struct Curl_easy *data = conn->data; 123 124 if(Curl_timeleft(data, NULL, TRUE) < 0) { 125 /* time-out, bail out, go home */ 126 failf(data, "Connection time-out"); 127 return CURLE_OPERATION_TIMEDOUT; 128 } 129 130 if(conn->bits.httpproxy) 131 infof(conn->data, "SOCKS4%s: connecting to HTTP proxy %s port %d\n", 132 protocol4a ? "a" : "", hostname, remote_port); 133 134 (void)curlx_nonblock(sock, FALSE); 135 136 infof(data, "SOCKS4 communication to %s:%d\n", hostname, remote_port); 137 138 /* 139 * Compose socks4 request 140 * 141 * Request format 142 * 143 * +----+----+----+----+----+----+----+----+----+----+....+----+ 144 * | VN | CD | DSTPORT | DSTIP | USERID |NULL| 145 * +----+----+----+----+----+----+----+----+----+----+....+----+ 146 * # of bytes: 1 1 2 4 variable 1 147 */ 148 149 socksreq[0] = 4; /* version (SOCKS4) */ 150 socksreq[1] = 1; /* connect */ 151 socksreq[2] = (unsigned char)((remote_port >> 8) & 0xff); /* PORT MSB */ 152 socksreq[3] = (unsigned char)(remote_port & 0xff); /* PORT LSB */ 153 154 /* DNS resolve only for SOCKS4, not SOCKS4a */ 155 if(!protocol4a) { 156 struct Curl_dns_entry *dns; 157 Curl_addrinfo *hp=NULL; 158 int rc; 159 160 rc = Curl_resolv(conn, hostname, remote_port, &dns); 161 162 if(rc == CURLRESOLV_ERROR) 163 return CURLE_COULDNT_RESOLVE_PROXY; 164 165 if(rc == CURLRESOLV_PENDING) 166 /* ignores the return code, but 'dns' remains NULL on failure */ 167 (void)Curl_resolver_wait_resolv(conn, &dns); 168 169 /* 170 * We cannot use 'hostent' as a struct that Curl_resolv() returns. It 171 * returns a Curl_addrinfo pointer that may not always look the same. 172 */ 173 if(dns) 174 hp=dns->addr; 175 if(hp) { 176 char buf[64]; 177 Curl_printable_address(hp, buf, sizeof(buf)); 178 179 if(hp->ai_family == AF_INET) { 180 struct sockaddr_in *saddr_in; 181 182 saddr_in = (struct sockaddr_in *)(void *)hp->ai_addr; 183 socksreq[4] = ((unsigned char *)&saddr_in->sin_addr.s_addr)[0]; 184 socksreq[5] = ((unsigned char *)&saddr_in->sin_addr.s_addr)[1]; 185 socksreq[6] = ((unsigned char *)&saddr_in->sin_addr.s_addr)[2]; 186 socksreq[7] = ((unsigned char *)&saddr_in->sin_addr.s_addr)[3]; 187 188 infof(data, "SOCKS4 connect to IPv4 %s (locally resolved)\n", buf); 189 } 190 else { 191 hp = NULL; /* fail! */ 192 193 failf(data, "SOCKS4 connection to %s not supported\n", buf); 194 } 195 196 Curl_resolv_unlock(data, dns); /* not used anymore from now on */ 197 } 198 if(!hp) { 199 failf(data, "Failed to resolve \"%s\" for SOCKS4 connect.", 200 hostname); 201 return CURLE_COULDNT_RESOLVE_HOST; 202 } 203 } 204 205 /* 206 * This is currently not supporting "Identification Protocol (RFC1413)". 207 */ 208 socksreq[8] = 0; /* ensure empty userid is NUL-terminated */ 209 if(proxy_name) { 210 size_t plen = strlen(proxy_name); 211 if(plen >= sizeof(socksreq) - 8) { 212 failf(data, "Too long SOCKS proxy name, can't use!\n"); 213 return CURLE_COULDNT_CONNECT; 214 } 215 /* copy the proxy name WITH trailing zero */ 216 memcpy(socksreq + 8, proxy_name, plen+1); 217 } 218 219 /* 220 * Make connection 221 */ 222 { 223 ssize_t actualread; 224 ssize_t written; 225 ssize_t hostnamelen = 0; 226 int packetsize = 9 + 227 (int)strlen((char *)socksreq + 8); /* size including NUL */ 228 229 /* If SOCKS4a, set special invalid IP address 0.0.0.x */ 230 if(protocol4a) { 231 socksreq[4] = 0; 232 socksreq[5] = 0; 233 socksreq[6] = 0; 234 socksreq[7] = 1; 235 /* If still enough room in buffer, also append hostname */ 236 hostnamelen = (ssize_t)strlen(hostname) + 1; /* length including NUL */ 237 if(packetsize + hostnamelen <= SOCKS4REQLEN) 238 strcpy((char *)socksreq + packetsize, hostname); 239 else 240 hostnamelen = 0; /* Flag: hostname did not fit in buffer */ 241 } 242 243 /* Send request */ 244 code = Curl_write_plain(conn, sock, (char *)socksreq, 245 packetsize + hostnamelen, 246 &written); 247 if(code || (written != packetsize + hostnamelen)) { 248 failf(data, "Failed to send SOCKS4 connect request."); 249 return CURLE_COULDNT_CONNECT; 250 } 251 if(protocol4a && hostnamelen == 0) { 252 /* SOCKS4a with very long hostname - send that name separately */ 253 hostnamelen = (ssize_t)strlen(hostname) + 1; 254 code = Curl_write_plain(conn, sock, (char *)hostname, hostnamelen, 255 &written); 256 if(code || (written != hostnamelen)) { 257 failf(data, "Failed to send SOCKS4 connect request."); 258 return CURLE_COULDNT_CONNECT; 259 } 260 } 261 262 packetsize = 8; /* receive data size */ 263 264 /* Receive response */ 265 result = Curl_blockread_all(conn, sock, (char *)socksreq, packetsize, 266 &actualread); 267 if(result || (actualread != packetsize)) { 268 failf(data, "Failed to receive SOCKS4 connect request ack."); 269 return CURLE_COULDNT_CONNECT; 270 } 271 272 /* 273 * Response format 274 * 275 * +----+----+----+----+----+----+----+----+ 276 * | VN | CD | DSTPORT | DSTIP | 277 * +----+----+----+----+----+----+----+----+ 278 * # of bytes: 1 1 2 4 279 * 280 * VN is the version of the reply code and should be 0. CD is the result 281 * code with one of the following values: 282 * 283 * 90: request granted 284 * 91: request rejected or failed 285 * 92: request rejected because SOCKS server cannot connect to 286 * identd on the client 287 * 93: request rejected because the client program and identd 288 * report different user-ids 289 */ 290 291 /* wrong version ? */ 292 if(socksreq[0] != 0) { 293 failf(data, 294 "SOCKS4 reply has wrong version, version should be 4."); 295 return CURLE_COULDNT_CONNECT; 296 } 297 298 /* Result */ 299 switch(socksreq[1]) { 300 case 90: 301 infof(data, "SOCKS4%s request granted.\n", protocol4a?"a":""); 302 break; 303 case 91: 304 failf(data, 305 "Can't complete SOCKS4 connection to %d.%d.%d.%d:%d. (%d)" 306 ", request rejected or failed.", 307 (unsigned char)socksreq[4], (unsigned char)socksreq[5], 308 (unsigned char)socksreq[6], (unsigned char)socksreq[7], 309 (((unsigned char)socksreq[8] << 8) | (unsigned char)socksreq[9]), 310 (unsigned char)socksreq[1]); 311 return CURLE_COULDNT_CONNECT; 312 case 92: 313 failf(data, 314 "Can't complete SOCKS4 connection to %d.%d.%d.%d:%d. (%d)" 315 ", request rejected because SOCKS server cannot connect to " 316 "identd on the client.", 317 (unsigned char)socksreq[4], (unsigned char)socksreq[5], 318 (unsigned char)socksreq[6], (unsigned char)socksreq[7], 319 (((unsigned char)socksreq[8] << 8) | (unsigned char)socksreq[9]), 320 (unsigned char)socksreq[1]); 321 return CURLE_COULDNT_CONNECT; 322 case 93: 323 failf(data, 324 "Can't complete SOCKS4 connection to %d.%d.%d.%d:%d. (%d)" 325 ", request rejected because the client program and identd " 326 "report different user-ids.", 327 (unsigned char)socksreq[4], (unsigned char)socksreq[5], 328 (unsigned char)socksreq[6], (unsigned char)socksreq[7], 329 (((unsigned char)socksreq[8] << 8) | (unsigned char)socksreq[9]), 330 (unsigned char)socksreq[1]); 331 return CURLE_COULDNT_CONNECT; 332 default: 333 failf(data, 334 "Can't complete SOCKS4 connection to %d.%d.%d.%d:%d. (%d)" 335 ", Unknown.", 336 (unsigned char)socksreq[4], (unsigned char)socksreq[5], 337 (unsigned char)socksreq[6], (unsigned char)socksreq[7], 338 (((unsigned char)socksreq[8] << 8) | (unsigned char)socksreq[9]), 339 (unsigned char)socksreq[1]); 340 return CURLE_COULDNT_CONNECT; 341 } 342 } 343 344 (void)curlx_nonblock(sock, TRUE); 345 346 return CURLE_OK; /* Proxy was successful! */ 347 } 348 349 /* 350 * This function logs in to a SOCKS5 proxy and sends the specifics to the final 351 * destination server. 352 */ 353 CURLcode Curl_SOCKS5(const char *proxy_name, 354 const char *proxy_password, 355 const char *hostname, 356 int remote_port, 357 int sockindex, 358 struct connectdata *conn) 359 { 360 /* 361 According to the RFC1928, section "6. Replies". This is what a SOCK5 362 replies: 363 364 +----+-----+-------+------+----------+----------+ 365 |VER | REP | RSV | ATYP | BND.ADDR | BND.PORT | 366 +----+-----+-------+------+----------+----------+ 367 | 1 | 1 | X'00' | 1 | Variable | 2 | 368 +----+-----+-------+------+----------+----------+ 369 370 Where: 371 372 o VER protocol version: X'05' 373 o REP Reply field: 374 o X'00' succeeded 375 */ 376 377 unsigned char socksreq[600]; /* room for large user/pw (255 max each) */ 378 ssize_t actualread; 379 ssize_t written; 380 int result; 381 CURLcode code; 382 curl_socket_t sock = conn->sock[sockindex]; 383 struct Curl_easy *data = conn->data; 384 time_t timeout; 385 bool socks5_resolve_local = 386 (conn->socks_proxy.proxytype == CURLPROXY_SOCKS5) ? TRUE : FALSE; 387 const size_t hostname_len = strlen(hostname); 388 ssize_t len = 0; 389 390 if(conn->bits.httpproxy) 391 infof(conn->data, "SOCKS5: connecting to HTTP proxy %s port %d\n", 392 hostname, remote_port); 393 394 /* RFC1928 chapter 5 specifies max 255 chars for domain name in packet */ 395 if(!socks5_resolve_local && hostname_len > 255) { 396 infof(conn->data, "SOCKS5: server resolving disabled for hostnames of " 397 "length > 255 [actual len=%zu]\n", hostname_len); 398 socks5_resolve_local = TRUE; 399 } 400 401 /* get timeout */ 402 timeout = Curl_timeleft(data, NULL, TRUE); 403 404 if(timeout < 0) { 405 /* time-out, bail out, go home */ 406 failf(data, "Connection time-out"); 407 return CURLE_OPERATION_TIMEDOUT; 408 } 409 410 (void)curlx_nonblock(sock, TRUE); 411 412 /* wait until socket gets connected */ 413 result = SOCKET_WRITABLE(sock, timeout); 414 415 if(-1 == result) { 416 failf(conn->data, "SOCKS5: no connection here"); 417 return CURLE_COULDNT_CONNECT; 418 } 419 else if(0 == result) { 420 failf(conn->data, "SOCKS5: connection timeout"); 421 return CURLE_OPERATION_TIMEDOUT; 422 } 423 424 if(result & CURL_CSELECT_ERR) { 425 failf(conn->data, "SOCKS5: error occurred during connection"); 426 return CURLE_COULDNT_CONNECT; 427 } 428 429 socksreq[0] = 5; /* version */ 430 #if defined(HAVE_GSSAPI) || defined(USE_WINDOWS_SSPI) 431 socksreq[1] = (char)(proxy_name ? 3 : 2); /* number of methods (below) */ 432 socksreq[2] = 0; /* no authentication */ 433 socksreq[3] = 1; /* GSS-API */ 434 socksreq[4] = 2; /* username/password */ 435 #else 436 socksreq[1] = (char)(proxy_name ? 2 : 1); /* number of methods (below) */ 437 socksreq[2] = 0; /* no authentication */ 438 socksreq[3] = 2; /* username/password */ 439 #endif 440 441 (void)curlx_nonblock(sock, FALSE); 442 443 infof(data, "SOCKS5 communication to %s:%d\n", hostname, remote_port); 444 445 code = Curl_write_plain(conn, sock, (char *)socksreq, (2 + (int)socksreq[1]), 446 &written); 447 if(code || (written != (2 + (int)socksreq[1]))) { 448 failf(data, "Unable to send initial SOCKS5 request."); 449 return CURLE_COULDNT_CONNECT; 450 } 451 452 (void)curlx_nonblock(sock, TRUE); 453 454 result = SOCKET_READABLE(sock, timeout); 455 456 if(-1 == result) { 457 failf(conn->data, "SOCKS5 nothing to read"); 458 return CURLE_COULDNT_CONNECT; 459 } 460 else if(0 == result) { 461 failf(conn->data, "SOCKS5 read timeout"); 462 return CURLE_OPERATION_TIMEDOUT; 463 } 464 465 if(result & CURL_CSELECT_ERR) { 466 failf(conn->data, "SOCKS5 read error occurred"); 467 return CURLE_RECV_ERROR; 468 } 469 470 (void)curlx_nonblock(sock, FALSE); 471 472 result=Curl_blockread_all(conn, sock, (char *)socksreq, 2, &actualread); 473 if(result || (actualread != 2)) { 474 failf(data, "Unable to receive initial SOCKS5 response."); 475 return CURLE_COULDNT_CONNECT; 476 } 477 478 if(socksreq[0] != 5) { 479 failf(data, "Received invalid version in initial SOCKS5 response."); 480 return CURLE_COULDNT_CONNECT; 481 } 482 if(socksreq[1] == 0) { 483 /* Nothing to do, no authentication needed */ 484 ; 485 } 486 #if defined(HAVE_GSSAPI) || defined(USE_WINDOWS_SSPI) 487 else if(socksreq[1] == 1) { 488 code = Curl_SOCKS5_gssapi_negotiate(sockindex, conn); 489 if(code) { 490 failf(data, "Unable to negotiate SOCKS5 GSS-API context."); 491 return CURLE_COULDNT_CONNECT; 492 } 493 } 494 #endif 495 else if(socksreq[1] == 2) { 496 /* Needs user name and password */ 497 size_t proxy_name_len, proxy_password_len; 498 if(proxy_name && proxy_password) { 499 proxy_name_len = strlen(proxy_name); 500 proxy_password_len = strlen(proxy_password); 501 } 502 else { 503 proxy_name_len = 0; 504 proxy_password_len = 0; 505 } 506 507 /* username/password request looks like 508 * +----+------+----------+------+----------+ 509 * |VER | ULEN | UNAME | PLEN | PASSWD | 510 * +----+------+----------+------+----------+ 511 * | 1 | 1 | 1 to 255 | 1 | 1 to 255 | 512 * +----+------+----------+------+----------+ 513 */ 514 len = 0; 515 socksreq[len++] = 1; /* username/pw subnegotiation version */ 516 socksreq[len++] = (unsigned char) proxy_name_len; 517 if(proxy_name && proxy_name_len) 518 memcpy(socksreq + len, proxy_name, proxy_name_len); 519 len += proxy_name_len; 520 socksreq[len++] = (unsigned char) proxy_password_len; 521 if(proxy_password && proxy_password_len) 522 memcpy(socksreq + len, proxy_password, proxy_password_len); 523 len += proxy_password_len; 524 525 code = Curl_write_plain(conn, sock, (char *)socksreq, len, &written); 526 if(code || (len != written)) { 527 failf(data, "Failed to send SOCKS5 sub-negotiation request."); 528 return CURLE_COULDNT_CONNECT; 529 } 530 531 result=Curl_blockread_all(conn, sock, (char *)socksreq, 2, &actualread); 532 if(result || (actualread != 2)) { 533 failf(data, "Unable to receive SOCKS5 sub-negotiation response."); 534 return CURLE_COULDNT_CONNECT; 535 } 536 537 /* ignore the first (VER) byte */ 538 if(socksreq[1] != 0) { /* status */ 539 failf(data, "User was rejected by the SOCKS5 server (%d %d).", 540 socksreq[0], socksreq[1]); 541 return CURLE_COULDNT_CONNECT; 542 } 543 544 /* Everything is good so far, user was authenticated! */ 545 } 546 else { 547 /* error */ 548 #if defined(HAVE_GSSAPI) || defined(USE_WINDOWS_SSPI) 549 if(socksreq[1] == 255) { 550 #else 551 if(socksreq[1] == 1) { 552 failf(data, 553 "SOCKS5 GSSAPI per-message authentication is not supported."); 554 return CURLE_COULDNT_CONNECT; 555 } 556 else if(socksreq[1] == 255) { 557 #endif 558 if(!proxy_name || !*proxy_name) { 559 failf(data, 560 "No authentication method was acceptable. (It is quite likely" 561 " that the SOCKS5 server wanted a username/password, since none" 562 " was supplied to the server on this connection.)"); 563 } 564 else { 565 failf(data, "No authentication method was acceptable."); 566 } 567 return CURLE_COULDNT_CONNECT; 568 } 569 else { 570 failf(data, 571 "Undocumented SOCKS5 mode attempted to be used by server."); 572 return CURLE_COULDNT_CONNECT; 573 } 574 } 575 576 /* Authentication is complete, now specify destination to the proxy */ 577 len = 0; 578 socksreq[len++] = 5; /* version (SOCKS5) */ 579 socksreq[len++] = 1; /* connect */ 580 socksreq[len++] = 0; /* must be zero */ 581 582 if(!socks5_resolve_local) { 583 socksreq[len++] = 3; /* ATYP: domain name = 3 */ 584 socksreq[len++] = (char) hostname_len; /* address length */ 585 memcpy(&socksreq[len], hostname, hostname_len); /* address str w/o NULL */ 586 len += hostname_len; 587 } 588 else { 589 struct Curl_dns_entry *dns; 590 Curl_addrinfo *hp = NULL; 591 int rc = Curl_resolv(conn, hostname, remote_port, &dns); 592 593 if(rc == CURLRESOLV_ERROR) 594 return CURLE_COULDNT_RESOLVE_HOST; 595 596 if(rc == CURLRESOLV_PENDING) { 597 /* this requires that we're in "wait for resolve" state */ 598 code = Curl_resolver_wait_resolv(conn, &dns); 599 if(code) 600 return code; 601 } 602 603 /* 604 * We cannot use 'hostent' as a struct that Curl_resolv() returns. It 605 * returns a Curl_addrinfo pointer that may not always look the same. 606 */ 607 if(dns) 608 hp=dns->addr; 609 if(hp) { 610 int i; 611 char buf[64]; 612 Curl_printable_address(hp, buf, sizeof(buf)); 613 614 if(hp->ai_family == AF_INET) { 615 struct sockaddr_in *saddr_in; 616 socksreq[len++] = 1; /* ATYP: IPv4 = 1 */ 617 618 saddr_in = (struct sockaddr_in *)(void *)hp->ai_addr; 619 for(i = 0; i < 4; i++) { 620 socksreq[len++] = ((unsigned char *)&saddr_in->sin_addr.s_addr)[i]; 621 } 622 623 infof(data, "SOCKS5 connect to IPv4 %s (locally resolved)\n", buf); 624 } 625 #ifdef ENABLE_IPV6 626 else if(hp->ai_family == AF_INET6) { 627 struct sockaddr_in6 *saddr_in6; 628 socksreq[len++] = 4; /* ATYP: IPv6 = 4 */ 629 630 saddr_in6 = (struct sockaddr_in6 *)(void *)hp->ai_addr; 631 for(i = 0; i < 16; i++) { 632 socksreq[len++] = 633 ((unsigned char *)&saddr_in6->sin6_addr.s6_addr)[i]; 634 } 635 636 infof(data, "SOCKS5 connect to IPv6 %s (locally resolved)\n", buf); 637 } 638 #endif 639 else { 640 hp = NULL; /* fail! */ 641 642 failf(data, "SOCKS5 connection to %s not supported\n", buf); 643 } 644 645 Curl_resolv_unlock(data, dns); /* not used anymore from now on */ 646 } 647 if(!hp) { 648 failf(data, "Failed to resolve \"%s\" for SOCKS5 connect.", 649 hostname); 650 return CURLE_COULDNT_RESOLVE_HOST; 651 } 652 } 653 654 socksreq[len++] = (unsigned char)((remote_port >> 8) & 0xff); /* PORT MSB */ 655 socksreq[len++] = (unsigned char)(remote_port & 0xff); /* PORT LSB */ 656 657 #if defined(HAVE_GSSAPI) || defined(USE_WINDOWS_SSPI) 658 if(conn->socks5_gssapi_enctype) { 659 failf(data, "SOCKS5 GSS-API protection not yet implemented."); 660 } 661 else 662 #endif 663 code = Curl_write_plain(conn, sock, (char *)socksreq, len, &written); 664 665 if(code || (len != written)) { 666 failf(data, "Failed to send SOCKS5 connect request."); 667 return CURLE_COULDNT_CONNECT; 668 } 669 670 len = 10; /* minimum packet size is 10 */ 671 672 #if defined(HAVE_GSSAPI) || defined(USE_WINDOWS_SSPI) 673 if(conn->socks5_gssapi_enctype) { 674 failf(data, "SOCKS5 GSS-API protection not yet implemented."); 675 } 676 else 677 #endif 678 result = Curl_blockread_all(conn, sock, (char *)socksreq, 679 len, &actualread); 680 681 if(result || (len != actualread)) { 682 failf(data, "Failed to receive SOCKS5 connect request ack."); 683 return CURLE_COULDNT_CONNECT; 684 } 685 686 if(socksreq[0] != 5) { /* version */ 687 failf(data, 688 "SOCKS5 reply has wrong version, version should be 5."); 689 return CURLE_COULDNT_CONNECT; 690 } 691 692 /* Fix: in general, returned BND.ADDR is variable length parameter by RFC 693 1928, so the reply packet should be read until the end to avoid errors at 694 subsequent protocol level. 695 696 +----+-----+-------+------+----------+----------+ 697 |VER | REP | RSV | ATYP | BND.ADDR | BND.PORT | 698 +----+-----+-------+------+----------+----------+ 699 | 1 | 1 | X'00' | 1 | Variable | 2 | 700 +----+-----+-------+------+----------+----------+ 701 702 ATYP: 703 o IP v4 address: X'01', BND.ADDR = 4 byte 704 o domain name: X'03', BND.ADDR = [ 1 byte length, string ] 705 o IP v6 address: X'04', BND.ADDR = 16 byte 706 */ 707 708 /* Calculate real packet size */ 709 if(socksreq[3] == 3) { 710 /* domain name */ 711 int addrlen = (int) socksreq[4]; 712 len = 5 + addrlen + 2; 713 } 714 else if(socksreq[3] == 4) { 715 /* IPv6 */ 716 len = 4 + 16 + 2; 717 } 718 719 /* At this point we already read first 10 bytes */ 720 #if defined(HAVE_GSSAPI) || defined(USE_WINDOWS_SSPI) 721 if(!conn->socks5_gssapi_enctype) { 722 /* decrypt_gssapi_blockread already read the whole packet */ 723 #endif 724 if(len > 10) { 725 result = Curl_blockread_all(conn, sock, (char *)&socksreq[10], 726 len - 10, &actualread); 727 if(result || ((len - 10) != actualread)) { 728 failf(data, "Failed to receive SOCKS5 connect request ack."); 729 return CURLE_COULDNT_CONNECT; 730 } 731 } 732 #if defined(HAVE_GSSAPI) || defined(USE_WINDOWS_SSPI) 733 } 734 #endif 735 736 if(socksreq[1] != 0) { /* Anything besides 0 is an error */ 737 if(socksreq[3] == 1) { 738 failf(data, 739 "Can't complete SOCKS5 connection to %d.%d.%d.%d:%d. (%d)", 740 (unsigned char)socksreq[4], (unsigned char)socksreq[5], 741 (unsigned char)socksreq[6], (unsigned char)socksreq[7], 742 (((unsigned char)socksreq[8] << 8) | 743 (unsigned char)socksreq[9]), 744 (unsigned char)socksreq[1]); 745 } 746 else if(socksreq[3] == 3) { 747 unsigned char port_upper = (unsigned char)socksreq[len - 2]; 748 socksreq[len - 2] = 0; 749 failf(data, 750 "Can't complete SOCKS5 connection to %s:%d. (%d)", 751 (char *)&socksreq[5], 752 ((port_upper << 8) | 753 (unsigned char)socksreq[len - 1]), 754 (unsigned char)socksreq[1]); 755 socksreq[len - 2] = port_upper; 756 } 757 else if(socksreq[3] == 4) { 758 failf(data, 759 "Can't complete SOCKS5 connection to %02x%02x:%02x%02x:" 760 "%02x%02x:%02x%02x:%02x%02x:%02x%02x:%02x%02x:%02x%02x:%d. (%d)", 761 (unsigned char)socksreq[4], (unsigned char)socksreq[5], 762 (unsigned char)socksreq[6], (unsigned char)socksreq[7], 763 (unsigned char)socksreq[8], (unsigned char)socksreq[9], 764 (unsigned char)socksreq[10], (unsigned char)socksreq[11], 765 (unsigned char)socksreq[12], (unsigned char)socksreq[13], 766 (unsigned char)socksreq[14], (unsigned char)socksreq[15], 767 (unsigned char)socksreq[16], (unsigned char)socksreq[17], 768 (unsigned char)socksreq[18], (unsigned char)socksreq[19], 769 (((unsigned char)socksreq[20] << 8) | 770 (unsigned char)socksreq[21]), 771 (unsigned char)socksreq[1]); 772 } 773 return CURLE_COULDNT_CONNECT; 774 } 775 else { 776 infof(data, "SOCKS5 request granted.\n"); 777 } 778 779 (void)curlx_nonblock(sock, TRUE); 780 return CURLE_OK; /* Proxy was successful! */ 781 } 782 783 #endif /* CURL_DISABLE_PROXY */ 784 785
