1 /*************************************************************************** 2 * _ _ ____ _ 3 * Project ___| | | | _ \| | 4 * / __| | | | |_) | | 5 * | (__| |_| | _ <| |___ 6 * \___|\___/|_| \_\_____| 7 * 8 * Copyright (C) 1998 - 2017, 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 timediff_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 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_user, 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_user) { 210 size_t plen = strlen(proxy_user); 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_user, 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[2] << 8) | (unsigned char)socksreq[3]), 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[2] << 8) | (unsigned char)socksreq[3]), 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[2] << 8) | (unsigned char)socksreq[3]), 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[2] << 8) | (unsigned char)socksreq[3]), 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_user, 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 int idx; 379 ssize_t actualread; 380 ssize_t written; 381 int result; 382 CURLcode code; 383 curl_socket_t sock = conn->sock[sockindex]; 384 struct Curl_easy *data = conn->data; 385 timediff_t timeout; 386 bool socks5_resolve_local = 387 (conn->socks_proxy.proxytype == CURLPROXY_SOCKS5) ? TRUE : FALSE; 388 const size_t hostname_len = strlen(hostname); 389 ssize_t len = 0; 390 const unsigned long auth = data->set.socks5auth; 391 bool allow_gssapi = FALSE; 392 393 if(conn->bits.httpproxy) 394 infof(conn->data, "SOCKS5: connecting to HTTP proxy %s port %d\n", 395 hostname, remote_port); 396 397 /* RFC1928 chapter 5 specifies max 255 chars for domain name in packet */ 398 if(!socks5_resolve_local && hostname_len > 255) { 399 infof(conn->data, "SOCKS5: server resolving disabled for hostnames of " 400 "length > 255 [actual len=%zu]\n", hostname_len); 401 socks5_resolve_local = TRUE; 402 } 403 404 /* get timeout */ 405 timeout = Curl_timeleft(data, NULL, TRUE); 406 407 if(timeout < 0) { 408 /* time-out, bail out, go home */ 409 failf(data, "Connection time-out"); 410 return CURLE_OPERATION_TIMEDOUT; 411 } 412 413 (void)curlx_nonblock(sock, TRUE); 414 415 /* wait until socket gets connected */ 416 result = SOCKET_WRITABLE(sock, timeout); 417 418 if(-1 == result) { 419 failf(conn->data, "SOCKS5: no connection here"); 420 return CURLE_COULDNT_CONNECT; 421 } 422 if(0 == result) { 423 failf(conn->data, "SOCKS5: connection timeout"); 424 return CURLE_OPERATION_TIMEDOUT; 425 } 426 427 if(result & CURL_CSELECT_ERR) { 428 failf(conn->data, "SOCKS5: error occurred during connection"); 429 return CURLE_COULDNT_CONNECT; 430 } 431 432 if(auth & ~(CURLAUTH_BASIC | CURLAUTH_GSSAPI)) 433 infof(conn->data, 434 "warning: unsupported value passed to CURLOPT_SOCKS5_AUTH: %lu\n", 435 auth); 436 if(!(auth & CURLAUTH_BASIC)) 437 /* disable username/password auth */ 438 proxy_user = NULL; 439 #if defined(HAVE_GSSAPI) || defined(USE_WINDOWS_SSPI) 440 if(auth & CURLAUTH_GSSAPI) 441 allow_gssapi = TRUE; 442 #endif 443 444 idx = 0; 445 socksreq[idx++] = 5; /* version */ 446 idx++; /* reserve for the number of authentication methods */ 447 socksreq[idx++] = 0; /* no authentication */ 448 if(allow_gssapi) 449 socksreq[idx++] = 1; /* GSS-API */ 450 if(proxy_user) 451 socksreq[idx++] = 2; /* username/password */ 452 /* write the number of authentication methods */ 453 socksreq[1] = (unsigned char) (idx - 2); 454 455 (void)curlx_nonblock(sock, FALSE); 456 457 infof(data, "SOCKS5 communication to %s:%d\n", hostname, remote_port); 458 459 code = Curl_write_plain(conn, sock, (char *)socksreq, (2 + (int)socksreq[1]), 460 &written); 461 if(code || (written != (2 + (int)socksreq[1]))) { 462 failf(data, "Unable to send initial SOCKS5 request."); 463 return CURLE_COULDNT_CONNECT; 464 } 465 466 (void)curlx_nonblock(sock, TRUE); 467 468 result = SOCKET_READABLE(sock, timeout); 469 470 if(-1 == result) { 471 failf(conn->data, "SOCKS5 nothing to read"); 472 return CURLE_COULDNT_CONNECT; 473 } 474 if(0 == result) { 475 failf(conn->data, "SOCKS5 read timeout"); 476 return CURLE_OPERATION_TIMEDOUT; 477 } 478 479 if(result & CURL_CSELECT_ERR) { 480 failf(conn->data, "SOCKS5 read error occurred"); 481 return CURLE_RECV_ERROR; 482 } 483 484 (void)curlx_nonblock(sock, FALSE); 485 486 result = Curl_blockread_all(conn, sock, (char *)socksreq, 2, &actualread); 487 if(result || (actualread != 2)) { 488 failf(data, "Unable to receive initial SOCKS5 response."); 489 return CURLE_COULDNT_CONNECT; 490 } 491 492 if(socksreq[0] != 5) { 493 failf(data, "Received invalid version in initial SOCKS5 response."); 494 return CURLE_COULDNT_CONNECT; 495 } 496 if(socksreq[1] == 0) { 497 /* Nothing to do, no authentication needed */ 498 ; 499 } 500 #if defined(HAVE_GSSAPI) || defined(USE_WINDOWS_SSPI) 501 else if(allow_gssapi && (socksreq[1] == 1)) { 502 code = Curl_SOCKS5_gssapi_negotiate(sockindex, conn); 503 if(code) { 504 failf(data, "Unable to negotiate SOCKS5 GSS-API context."); 505 return CURLE_COULDNT_CONNECT; 506 } 507 } 508 #endif 509 else if(socksreq[1] == 2) { 510 /* Needs user name and password */ 511 size_t proxy_user_len, proxy_password_len; 512 if(proxy_user && proxy_password) { 513 proxy_user_len = strlen(proxy_user); 514 proxy_password_len = strlen(proxy_password); 515 } 516 else { 517 proxy_user_len = 0; 518 proxy_password_len = 0; 519 } 520 521 /* username/password request looks like 522 * +----+------+----------+------+----------+ 523 * |VER | ULEN | UNAME | PLEN | PASSWD | 524 * +----+------+----------+------+----------+ 525 * | 1 | 1 | 1 to 255 | 1 | 1 to 255 | 526 * +----+------+----------+------+----------+ 527 */ 528 len = 0; 529 socksreq[len++] = 1; /* username/pw subnegotiation version */ 530 socksreq[len++] = (unsigned char) proxy_user_len; 531 if(proxy_user && proxy_user_len) 532 memcpy(socksreq + len, proxy_user, proxy_user_len); 533 len += proxy_user_len; 534 socksreq[len++] = (unsigned char) proxy_password_len; 535 if(proxy_password && proxy_password_len) 536 memcpy(socksreq + len, proxy_password, proxy_password_len); 537 len += proxy_password_len; 538 539 code = Curl_write_plain(conn, sock, (char *)socksreq, len, &written); 540 if(code || (len != written)) { 541 failf(data, "Failed to send SOCKS5 sub-negotiation request."); 542 return CURLE_COULDNT_CONNECT; 543 } 544 545 result = Curl_blockread_all(conn, sock, (char *)socksreq, 2, &actualread); 546 if(result || (actualread != 2)) { 547 failf(data, "Unable to receive SOCKS5 sub-negotiation response."); 548 return CURLE_COULDNT_CONNECT; 549 } 550 551 /* ignore the first (VER) byte */ 552 if(socksreq[1] != 0) { /* status */ 553 failf(data, "User was rejected by the SOCKS5 server (%d %d).", 554 socksreq[0], socksreq[1]); 555 return CURLE_COULDNT_CONNECT; 556 } 557 558 /* Everything is good so far, user was authenticated! */ 559 } 560 else { 561 /* error */ 562 if(!allow_gssapi && (socksreq[1] == 1)) { 563 failf(data, 564 "SOCKS5 GSSAPI per-message authentication is not supported."); 565 return CURLE_COULDNT_CONNECT; 566 } 567 if(socksreq[1] == 255) { 568 if(!proxy_user || !*proxy_user) { 569 failf(data, 570 "No authentication method was acceptable. (It is quite likely" 571 " that the SOCKS5 server wanted a username/password, since none" 572 " was supplied to the server on this connection.)"); 573 } 574 else { 575 failf(data, "No authentication method was acceptable."); 576 } 577 return CURLE_COULDNT_CONNECT; 578 } 579 else { 580 failf(data, 581 "Undocumented SOCKS5 mode attempted to be used by server."); 582 return CURLE_COULDNT_CONNECT; 583 } 584 } 585 586 /* Authentication is complete, now specify destination to the proxy */ 587 len = 0; 588 socksreq[len++] = 5; /* version (SOCKS5) */ 589 socksreq[len++] = 1; /* connect */ 590 socksreq[len++] = 0; /* must be zero */ 591 592 if(!socks5_resolve_local) { 593 socksreq[len++] = 3; /* ATYP: domain name = 3 */ 594 socksreq[len++] = (char) hostname_len; /* address length */ 595 memcpy(&socksreq[len], hostname, hostname_len); /* address str w/o NULL */ 596 len += hostname_len; 597 } 598 else { 599 struct Curl_dns_entry *dns; 600 Curl_addrinfo *hp = NULL; 601 int rc = Curl_resolv(conn, hostname, remote_port, &dns); 602 603 if(rc == CURLRESOLV_ERROR) 604 return CURLE_COULDNT_RESOLVE_HOST; 605 606 if(rc == CURLRESOLV_PENDING) { 607 /* this requires that we're in "wait for resolve" state */ 608 code = Curl_resolver_wait_resolv(conn, &dns); 609 if(code) 610 return code; 611 } 612 613 /* 614 * We cannot use 'hostent' as a struct that Curl_resolv() returns. It 615 * returns a Curl_addrinfo pointer that may not always look the same. 616 */ 617 if(dns) 618 hp = dns->addr; 619 if(hp) { 620 int i; 621 char buf[64]; 622 Curl_printable_address(hp, buf, sizeof(buf)); 623 624 if(hp->ai_family == AF_INET) { 625 struct sockaddr_in *saddr_in; 626 socksreq[len++] = 1; /* ATYP: IPv4 = 1 */ 627 628 saddr_in = (struct sockaddr_in *)(void *)hp->ai_addr; 629 for(i = 0; i < 4; i++) { 630 socksreq[len++] = ((unsigned char *)&saddr_in->sin_addr.s_addr)[i]; 631 } 632 633 infof(data, "SOCKS5 connect to IPv4 %s (locally resolved)\n", buf); 634 } 635 #ifdef ENABLE_IPV6 636 else if(hp->ai_family == AF_INET6) { 637 struct sockaddr_in6 *saddr_in6; 638 socksreq[len++] = 4; /* ATYP: IPv6 = 4 */ 639 640 saddr_in6 = (struct sockaddr_in6 *)(void *)hp->ai_addr; 641 for(i = 0; i < 16; i++) { 642 socksreq[len++] = 643 ((unsigned char *)&saddr_in6->sin6_addr.s6_addr)[i]; 644 } 645 646 infof(data, "SOCKS5 connect to IPv6 %s (locally resolved)\n", buf); 647 } 648 #endif 649 else { 650 hp = NULL; /* fail! */ 651 652 failf(data, "SOCKS5 connection to %s not supported\n", buf); 653 } 654 655 Curl_resolv_unlock(data, dns); /* not used anymore from now on */ 656 } 657 if(!hp) { 658 failf(data, "Failed to resolve \"%s\" for SOCKS5 connect.", 659 hostname); 660 return CURLE_COULDNT_RESOLVE_HOST; 661 } 662 } 663 664 socksreq[len++] = (unsigned char)((remote_port >> 8) & 0xff); /* PORT MSB */ 665 socksreq[len++] = (unsigned char)(remote_port & 0xff); /* PORT LSB */ 666 667 #if defined(HAVE_GSSAPI) || defined(USE_WINDOWS_SSPI) 668 if(conn->socks5_gssapi_enctype) { 669 failf(data, "SOCKS5 GSS-API protection not yet implemented."); 670 } 671 else 672 #endif 673 code = Curl_write_plain(conn, sock, (char *)socksreq, len, &written); 674 675 if(code || (len != written)) { 676 failf(data, "Failed to send SOCKS5 connect request."); 677 return CURLE_COULDNT_CONNECT; 678 } 679 680 len = 10; /* minimum packet size is 10 */ 681 682 #if defined(HAVE_GSSAPI) || defined(USE_WINDOWS_SSPI) 683 if(conn->socks5_gssapi_enctype) { 684 failf(data, "SOCKS5 GSS-API protection not yet implemented."); 685 } 686 else 687 #endif 688 result = Curl_blockread_all(conn, sock, (char *)socksreq, 689 len, &actualread); 690 691 if(result || (len != actualread)) { 692 failf(data, "Failed to receive SOCKS5 connect request ack."); 693 return CURLE_COULDNT_CONNECT; 694 } 695 696 if(socksreq[0] != 5) { /* version */ 697 failf(data, 698 "SOCKS5 reply has wrong version, version should be 5."); 699 return CURLE_COULDNT_CONNECT; 700 } 701 702 /* Fix: in general, returned BND.ADDR is variable length parameter by RFC 703 1928, so the reply packet should be read until the end to avoid errors at 704 subsequent protocol level. 705 706 +----+-----+-------+------+----------+----------+ 707 |VER | REP | RSV | ATYP | BND.ADDR | BND.PORT | 708 +----+-----+-------+------+----------+----------+ 709 | 1 | 1 | X'00' | 1 | Variable | 2 | 710 +----+-----+-------+------+----------+----------+ 711 712 ATYP: 713 o IP v4 address: X'01', BND.ADDR = 4 byte 714 o domain name: X'03', BND.ADDR = [ 1 byte length, string ] 715 o IP v6 address: X'04', BND.ADDR = 16 byte 716 */ 717 718 /* Calculate real packet size */ 719 if(socksreq[3] == 3) { 720 /* domain name */ 721 int addrlen = (int) socksreq[4]; 722 len = 5 + addrlen + 2; 723 } 724 else if(socksreq[3] == 4) { 725 /* IPv6 */ 726 len = 4 + 16 + 2; 727 } 728 729 /* At this point we already read first 10 bytes */ 730 #if defined(HAVE_GSSAPI) || defined(USE_WINDOWS_SSPI) 731 if(!conn->socks5_gssapi_enctype) { 732 /* decrypt_gssapi_blockread already read the whole packet */ 733 #endif 734 if(len > 10) { 735 result = Curl_blockread_all(conn, sock, (char *)&socksreq[10], 736 len - 10, &actualread); 737 if(result || ((len - 10) != actualread)) { 738 failf(data, "Failed to receive SOCKS5 connect request ack."); 739 return CURLE_COULDNT_CONNECT; 740 } 741 } 742 #if defined(HAVE_GSSAPI) || defined(USE_WINDOWS_SSPI) 743 } 744 #endif 745 746 if(socksreq[1] != 0) { /* Anything besides 0 is an error */ 747 if(socksreq[3] == 1) { 748 failf(data, 749 "Can't complete SOCKS5 connection to %d.%d.%d.%d:%d. (%d)", 750 (unsigned char)socksreq[4], (unsigned char)socksreq[5], 751 (unsigned char)socksreq[6], (unsigned char)socksreq[7], 752 (((unsigned char)socksreq[8] << 8) | 753 (unsigned char)socksreq[9]), 754 (unsigned char)socksreq[1]); 755 } 756 else if(socksreq[3] == 3) { 757 unsigned char port_upper = (unsigned char)socksreq[len - 2]; 758 socksreq[len - 2] = 0; 759 failf(data, 760 "Can't complete SOCKS5 connection to %s:%d. (%d)", 761 (char *)&socksreq[5], 762 ((port_upper << 8) | 763 (unsigned char)socksreq[len - 1]), 764 (unsigned char)socksreq[1]); 765 socksreq[len - 2] = port_upper; 766 } 767 else if(socksreq[3] == 4) { 768 failf(data, 769 "Can't complete SOCKS5 connection to %02x%02x:%02x%02x:" 770 "%02x%02x:%02x%02x:%02x%02x:%02x%02x:%02x%02x:%02x%02x:%d. (%d)", 771 (unsigned char)socksreq[4], (unsigned char)socksreq[5], 772 (unsigned char)socksreq[6], (unsigned char)socksreq[7], 773 (unsigned char)socksreq[8], (unsigned char)socksreq[9], 774 (unsigned char)socksreq[10], (unsigned char)socksreq[11], 775 (unsigned char)socksreq[12], (unsigned char)socksreq[13], 776 (unsigned char)socksreq[14], (unsigned char)socksreq[15], 777 (unsigned char)socksreq[16], (unsigned char)socksreq[17], 778 (unsigned char)socksreq[18], (unsigned char)socksreq[19], 779 (((unsigned char)socksreq[20] << 8) | 780 (unsigned char)socksreq[21]), 781 (unsigned char)socksreq[1]); 782 } 783 return CURLE_COULDNT_CONNECT; 784 } 785 infof(data, "SOCKS5 request granted.\n"); 786 787 (void)curlx_nonblock(sock, TRUE); 788 return CURLE_OK; /* Proxy was successful! */ 789 } 790 791 #endif /* CURL_DISABLE_PROXY */ 792 793
