/*************************************************************************** * _ _ ____ _ * Project ___| | | | _ \| | * / __| | | | |_) | | * | (__| |_| | _ <| |___ * \___|\___/|_| \_\_____| * * Copyright (C) 1998 - 2011, Daniel Stenberg, , et al. * * This software is licensed as described in the file COPYING, which * you should have received as part of this distribution. The terms * are also available at http://curl.haxx.se/docs/copyright.html. * * You may opt to use, copy, modify, merge, publish, distribute and/or sell * copies of the Software, and permit persons to whom the Software is * furnished to do so, under the terms of the COPYING file. * * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY * KIND, either express or implied. * ***************************************************************************/ #include "setup.h" #if !defined(CURL_DISABLE_PROXY) || defined(USE_WINDOWS_SSPI) #ifdef HAVE_SYS_SOCKET_H #include #endif #ifdef HAVE_NETINET_IN_H #include #endif #ifdef HAVE_ARPA_INET_H #include #endif #include "urldata.h" #include "sendf.h" #include "strequal.h" #include "select.h" #include "connect.h" #include "timeval.h" #include "socks.h" /* The last #include file should be: */ #include "memdebug.h" /* * Helper read-from-socket functions. Does the same as Curl_read() but it * blocks until all bytes amount of buffersize will be read. No more, no less. * * This is STUPID BLOCKING behaviour which we frown upon, but right now this * is what we have... */ int Curl_blockread_all(struct connectdata *conn, /* connection data */ curl_socket_t sockfd, /* read from this socket */ char *buf, /* store read data here */ ssize_t buffersize, /* max amount to read */ ssize_t *n) /* amount bytes read */ { ssize_t nread; ssize_t allread = 0; int result; long timeleft; *n = 0; for(;;) { timeleft = Curl_timeleft(conn->data, NULL, TRUE); if(timeleft < 0) { /* we already got the timeout */ result = CURLE_OPERATION_TIMEDOUT; break; } if(Curl_socket_ready(sockfd, CURL_SOCKET_BAD, timeleft) <= 0) { result = ~CURLE_OK; break; } result = Curl_read_plain(sockfd, buf, buffersize, &nread); if(CURLE_AGAIN == result) continue; else if(result) break; if(buffersize == nread) { allread += nread; *n = allread; result = CURLE_OK; break; } if(!nread) { result = ~CURLE_OK; break; } buffersize -= nread; buf += nread; allread += nread; } return result; } /* * This function logs in to a SOCKS4 proxy and sends the specifics to the final * destination server. * * Reference : * http://socks.permeo.com/protocol/socks4.protocol * * Note : * Set protocol4a=true for "SOCKS 4A (Simple Extension to SOCKS 4 Protocol)" * Nonsupport "Identification Protocol (RFC1413)" */ CURLcode Curl_SOCKS4(const char *proxy_name, const char *hostname, int remote_port, int sockindex, struct connectdata *conn, bool protocol4a) { #define SOCKS4REQLEN 262 unsigned char socksreq[SOCKS4REQLEN]; /* room for SOCKS4 request incl. user id */ int result; CURLcode code; curl_socket_t sock = conn->sock[sockindex]; struct SessionHandle *data = conn->data; if(Curl_timeleft(data, NULL, TRUE) < 0) { /* time-out, bail out, go home */ failf(data, "Connection time-out"); return CURLE_OPERATION_TIMEDOUT; } curlx_nonblock(sock, FALSE); /* * Compose socks4 request * * Request format * * +----+----+----+----+----+----+----+----+----+----+....+----+ * | VN | CD | DSTPORT | DSTIP | USERID |NULL| * +----+----+----+----+----+----+----+----+----+----+....+----+ * # of bytes: 1 1 2 4 variable 1 */ socksreq[0] = 4; /* version (SOCKS4) */ socksreq[1] = 1; /* connect */ socksreq[2] = (unsigned char)((remote_port >> 8) & 0xff); /* PORT MSB */ socksreq[3] = (unsigned char)(remote_port & 0xff); /* PORT LSB */ /* DNS resolve only for SOCKS4, not SOCKS4a */ if(!protocol4a) { struct Curl_dns_entry *dns; Curl_addrinfo *hp=NULL; int rc; rc = Curl_resolv(conn, hostname, remote_port, &dns); if(rc == CURLRESOLV_ERROR) return CURLE_COULDNT_RESOLVE_PROXY; if(rc == CURLRESOLV_PENDING) /* ignores the return code, but 'dns' remains NULL on failure */ (void)Curl_resolver_wait_resolv(conn, &dns); /* * We cannot use 'hostent' as a struct that Curl_resolv() returns. It * returns a Curl_addrinfo pointer that may not always look the same. */ if(dns) hp=dns->addr; if(hp) { char buf[64]; unsigned short ip[4]; Curl_printable_address(hp, buf, sizeof(buf)); if(4 == sscanf( buf, "%hu.%hu.%hu.%hu", &ip[0], &ip[1], &ip[2], &ip[3])) { /* Set DSTIP */ socksreq[4] = (unsigned char)ip[0]; socksreq[5] = (unsigned char)ip[1]; socksreq[6] = (unsigned char)ip[2]; socksreq[7] = (unsigned char)ip[3]; } else hp = NULL; /* fail! */ Curl_resolv_unlock(data, dns); /* not used anymore from now on */ } if(!hp) { failf(data, "Failed to resolve \"%s\" for SOCKS4 connect.", hostname); return CURLE_COULDNT_RESOLVE_HOST; } } /* * This is currently not supporting "Identification Protocol (RFC1413)". */ socksreq[8] = 0; /* ensure empty userid is NUL-terminated */ if(proxy_name) strlcat((char*)socksreq + 8, proxy_name, sizeof(socksreq) - 8); /* * Make connection */ { ssize_t actualread; ssize_t written; ssize_t hostnamelen = 0; int packetsize = 9 + (int)strlen((char*)socksreq + 8); /* size including NUL */ /* If SOCKS4a, set special invalid IP address 0.0.0.x */ if(protocol4a) { socksreq[4] = 0; socksreq[5] = 0; socksreq[6] = 0; socksreq[7] = 1; /* If still enough room in buffer, also append hostname */ hostnamelen = (ssize_t)strlen(hostname) + 1; /* length including NUL */ if(packetsize + hostnamelen <= SOCKS4REQLEN) strcpy((char*)socksreq + packetsize, hostname); else hostnamelen = 0; /* Flag: hostname did not fit in buffer */ } /* Send request */ code = Curl_write_plain(conn, sock, (char *)socksreq, packetsize + hostnamelen, &written); if((code != CURLE_OK) || (written != packetsize + hostnamelen)) { failf(data, "Failed to send SOCKS4 connect request."); return CURLE_COULDNT_CONNECT; } if(protocol4a && hostnamelen == 0) { /* SOCKS4a with very long hostname - send that name separately */ hostnamelen = (ssize_t)strlen(hostname) + 1; code = Curl_write_plain(conn, sock, (char *)hostname, hostnamelen, &written); if((code != CURLE_OK) || (written != hostnamelen)) { failf(data, "Failed to send SOCKS4 connect request."); return CURLE_COULDNT_CONNECT; } } packetsize = 8; /* receive data size */ /* Receive response */ result = Curl_blockread_all(conn, sock, (char *)socksreq, packetsize, &actualread); if((result != CURLE_OK) || (actualread != packetsize)) { failf(data, "Failed to receive SOCKS4 connect request ack."); return CURLE_COULDNT_CONNECT; } /* * Response format * * +----+----+----+----+----+----+----+----+ * | VN | CD | DSTPORT | DSTIP | * +----+----+----+----+----+----+----+----+ * # of bytes: 1 1 2 4 * * VN is the version of the reply code and should be 0. CD is the result * code with one of the following values: * * 90: request granted * 91: request rejected or failed * 92: request rejected because SOCKS server cannot connect to * identd on the client * 93: request rejected because the client program and identd * report different user-ids */ /* wrong version ? */ if(socksreq[0] != 0) { failf(data, "SOCKS4 reply has wrong version, version should be 4."); return CURLE_COULDNT_CONNECT; } /* Result */ switch(socksreq[1]) { case 90: infof(data, "SOCKS4%s request granted.\n", protocol4a?"a":""); break; case 91: failf(data, "Can't complete SOCKS4 connection to %d.%d.%d.%d:%d. (%d)" ", request rejected or failed.", (unsigned char)socksreq[4], (unsigned char)socksreq[5], (unsigned char)socksreq[6], (unsigned char)socksreq[7], ((socksreq[8] << 8) | socksreq[9]), socksreq[1]); return CURLE_COULDNT_CONNECT; case 92: failf(data, "Can't complete SOCKS4 connection to %d.%d.%d.%d:%d. (%d)" ", request rejected because SOCKS server cannot connect to " "identd on the client.", (unsigned char)socksreq[4], (unsigned char)socksreq[5], (unsigned char)socksreq[6], (unsigned char)socksreq[7], ((socksreq[8] << 8) | socksreq[9]), socksreq[1]); return CURLE_COULDNT_CONNECT; case 93: failf(data, "Can't complete SOCKS4 connection to %d.%d.%d.%d:%d. (%d)" ", request rejected because the client program and identd " "report different user-ids.", (unsigned char)socksreq[4], (unsigned char)socksreq[5], (unsigned char)socksreq[6], (unsigned char)socksreq[7], ((socksreq[8] << 8) | socksreq[9]), socksreq[1]); return CURLE_COULDNT_CONNECT; default: failf(data, "Can't complete SOCKS4 connection to %d.%d.%d.%d:%d. (%d)" ", Unknown.", (unsigned char)socksreq[4], (unsigned char)socksreq[5], (unsigned char)socksreq[6], (unsigned char)socksreq[7], ((socksreq[8] << 8) | socksreq[9]), socksreq[1]); return CURLE_COULDNT_CONNECT; } } curlx_nonblock(sock, TRUE); return CURLE_OK; /* Proxy was successful! */ } /* * This function logs in to a SOCKS5 proxy and sends the specifics to the final * destination server. */ CURLcode Curl_SOCKS5(const char *proxy_name, const char *proxy_password, const char *hostname, int remote_port, int sockindex, struct connectdata *conn) { /* According to the RFC1928, section "6. Replies". This is what a SOCK5 replies: +----+-----+-------+------+----------+----------+ |VER | REP | RSV | ATYP | BND.ADDR | BND.PORT | +----+-----+-------+------+----------+----------+ | 1 | 1 | X'00' | 1 | Variable | 2 | +----+-----+-------+------+----------+----------+ Where: o VER protocol version: X'05' o REP Reply field: o X'00' succeeded */ unsigned char socksreq[600]; /* room for large user/pw (255 max each) */ ssize_t actualread; ssize_t written; int result; CURLcode code; curl_socket_t sock = conn->sock[sockindex]; struct SessionHandle *data = conn->data; long timeout; bool socks5_resolve_local = (conn->proxytype == CURLPROXY_SOCKS5)?TRUE:FALSE; const size_t hostname_len = strlen(hostname); ssize_t packetsize = 0; /* RFC1928 chapter 5 specifies max 255 chars for domain name in packet */ if(!socks5_resolve_local && hostname_len > 255) { infof(conn->data,"SOCKS5: server resolving disabled for hostnames of " "length > 255 [actual len=%zu]\n", hostname_len); socks5_resolve_local = TRUE; } /* get timeout */ timeout = Curl_timeleft(data, NULL, TRUE); if(timeout < 0) { /* time-out, bail out, go home */ failf(data, "Connection time-out"); return CURLE_OPERATION_TIMEDOUT; } curlx_nonblock(sock, TRUE); /* wait until socket gets connected */ result = Curl_socket_ready(CURL_SOCKET_BAD, sock, timeout); if(-1 == result) { failf(conn->data, "SOCKS5: no connection here"); return CURLE_COULDNT_CONNECT; } else if(0 == result) { failf(conn->data, "SOCKS5: connection timeout"); return CURLE_OPERATION_TIMEDOUT; } if(result & CURL_CSELECT_ERR) { failf(conn->data, "SOCKS5: error occurred during connection"); return CURLE_COULDNT_CONNECT; } socksreq[0] = 5; /* version */ #if defined(HAVE_GSSAPI) || defined(USE_WINDOWS_SSPI) socksreq[1] = (char)(proxy_name ? 3 : 2); /* number of methods (below) */ socksreq[2] = 0; /* no authentication */ socksreq[3] = 1; /* gssapi */ socksreq[4] = 2; /* username/password */ #else socksreq[1] = (char)(proxy_name ? 2 : 1); /* number of methods (below) */ socksreq[2] = 0; /* no authentication */ socksreq[3] = 2; /* username/password */ #endif curlx_nonblock(sock, FALSE); code = Curl_write_plain(conn, sock, (char *)socksreq, (2 + (int)socksreq[1]), &written); if((code != CURLE_OK) || (written != (2 + (int)socksreq[1]))) { failf(data, "Unable to send initial SOCKS5 request."); return CURLE_COULDNT_CONNECT; } curlx_nonblock(sock, TRUE); result = Curl_socket_ready(sock, CURL_SOCKET_BAD, timeout); if(-1 == result) { failf(conn->data, "SOCKS5 nothing to read"); return CURLE_COULDNT_CONNECT; } else if(0 == result) { failf(conn->data, "SOCKS5 read timeout"); return CURLE_OPERATION_TIMEDOUT; } if(result & CURL_CSELECT_ERR) { failf(conn->data, "SOCKS5 read error occurred"); return CURLE_RECV_ERROR; } curlx_nonblock(sock, FALSE); result=Curl_blockread_all(conn, sock, (char *)socksreq, 2, &actualread); if((result != CURLE_OK) || (actualread != 2)) { failf(data, "Unable to receive initial SOCKS5 response."); return CURLE_COULDNT_CONNECT; } if(socksreq[0] != 5) { failf(data, "Received invalid version in initial SOCKS5 response."); return CURLE_COULDNT_CONNECT; } if(socksreq[1] == 0) { /* Nothing to do, no authentication needed */ ; } #if defined(HAVE_GSSAPI) || defined(USE_WINDOWS_SSPI) else if(socksreq[1] == 1) { code = Curl_SOCKS5_gssapi_negotiate(sockindex, conn); if(code != CURLE_OK) { failf(data, "Unable to negotiate SOCKS5 gssapi context."); return CURLE_COULDNT_CONNECT; } } #endif else if(socksreq[1] == 2) { /* Needs user name and password */ size_t userlen, pwlen; int len; if(proxy_name && proxy_password) { userlen = strlen(proxy_name); pwlen = strlen(proxy_password); } else { userlen = 0; pwlen = 0; } /* username/password request looks like * +----+------+----------+------+----------+ * |VER | ULEN | UNAME | PLEN | PASSWD | * +----+------+----------+------+----------+ * | 1 | 1 | 1 to 255 | 1 | 1 to 255 | * +----+------+----------+------+----------+ */ len = 0; socksreq[len++] = 1; /* username/pw subnegotiation version */ socksreq[len++] = (unsigned char) userlen; if(proxy_name && userlen) memcpy(socksreq + len, proxy_name, userlen); len += (int)userlen; socksreq[len++] = (unsigned char) pwlen; if(proxy_password && pwlen) memcpy(socksreq + len, proxy_password, pwlen); len += (int)pwlen; code = Curl_write_plain(conn, sock, (char *)socksreq, len, &written); if((code != CURLE_OK) || (len != written)) { failf(data, "Failed to send SOCKS5 sub-negotiation request."); return CURLE_COULDNT_CONNECT; } result=Curl_blockread_all(conn, sock, (char *)socksreq, 2, &actualread); if((result != CURLE_OK) || (actualread != 2)) { failf(data, "Unable to receive SOCKS5 sub-negotiation response."); return CURLE_COULDNT_CONNECT; } /* ignore the first (VER) byte */ if(socksreq[1] != 0) { /* status */ failf(data, "User was rejected by the SOCKS5 server (%d %d).", socksreq[0], socksreq[1]); return CURLE_COULDNT_CONNECT; } /* Everything is good so far, user was authenticated! */ } else { /* error */ #if defined(HAVE_GSSAPI) || defined(USE_WINDOWS_SSPI) if(socksreq[1] == 255) { #else if(socksreq[1] == 1) { failf(data, "SOCKS5 GSSAPI per-message authentication is not supported."); return CURLE_COULDNT_CONNECT; } else if(socksreq[1] == 255) { #endif if(!proxy_name || !*proxy_name) { failf(data, "No authentication method was acceptable. (It is quite likely" " that the SOCKS5 server wanted a username/password, since none" " was supplied to the server on this connection.)"); } else { failf(data, "No authentication method was acceptable."); } return CURLE_COULDNT_CONNECT; } else { failf(data, "Undocumented SOCKS5 mode attempted to be used by server."); return CURLE_COULDNT_CONNECT; } } /* Authentication is complete, now specify destination to the proxy */ socksreq[0] = 5; /* version (SOCKS5) */ socksreq[1] = 1; /* connect */ socksreq[2] = 0; /* must be zero */ if(!socks5_resolve_local) { packetsize = (ssize_t)(5 + hostname_len + 2); socksreq[3] = 3; /* ATYP: domain name = 3 */ socksreq[4] = (char) hostname_len; /* address length */ memcpy(&socksreq[5], hostname, hostname_len); /* address bytes w/o NULL */ /* PORT MSB */ socksreq[hostname_len+5] = (unsigned char)((remote_port >> 8) & 0xff); /* PORT LSB */ socksreq[hostname_len+6] = (unsigned char)(remote_port & 0xff); } else { struct Curl_dns_entry *dns; Curl_addrinfo *hp=NULL; int rc = Curl_resolv(conn, hostname, remote_port, &dns); packetsize = 10; socksreq[3] = 1; /* IPv4 = 1 */ if(rc == CURLRESOLV_ERROR) return CURLE_COULDNT_RESOLVE_HOST; if(rc == CURLRESOLV_PENDING) { /* this requires that we're in "wait for resolve" state */ code = Curl_resolver_wait_resolv(conn, &dns); if(code != CURLE_OK) return code; } /* * We cannot use 'hostent' as a struct that Curl_resolv() returns. It * returns a Curl_addrinfo pointer that may not always look the same. */ if(dns) hp=dns->addr; if(hp) { char buf[64]; unsigned short ip[4]; Curl_printable_address(hp, buf, sizeof(buf)); if(4 == sscanf( buf, "%hu.%hu.%hu.%hu", &ip[0], &ip[1], &ip[2], &ip[3])) { socksreq[4] = (unsigned char)ip[0]; socksreq[5] = (unsigned char)ip[1]; socksreq[6] = (unsigned char)ip[2]; socksreq[7] = (unsigned char)ip[3]; } else hp = NULL; /* fail! */ Curl_resolv_unlock(data, dns); /* not used anymore from now on */ } if(!hp) { failf(data, "Failed to resolve \"%s\" for SOCKS5 connect.", hostname); return CURLE_COULDNT_RESOLVE_HOST; } socksreq[8] = (unsigned char)((remote_port >> 8) & 0xff); /* PORT MSB */ socksreq[9] = (unsigned char)(remote_port & 0xff); /* PORT LSB */ } #if defined(HAVE_GSSAPI) || defined(USE_WINDOWS_SSPI) if(conn->socks5_gssapi_enctype) { failf(data, "SOCKS5 gssapi protection not yet implemented."); } else #endif code = Curl_write_plain(conn, sock, (char *)socksreq, packetsize, &written); if((code != CURLE_OK) || (written != packetsize)) { failf(data, "Failed to send SOCKS5 connect request."); return CURLE_COULDNT_CONNECT; } packetsize = 10; /* minimum packet size is 10 */ #if defined(HAVE_GSSAPI) || defined(USE_WINDOWS_SSPI) if(conn->socks5_gssapi_enctype) { failf(data, "SOCKS5 gssapi protection not yet implemented."); } else #endif result = Curl_blockread_all(conn, sock, (char *)socksreq, packetsize, &actualread); if((result != CURLE_OK) || (actualread != packetsize)) { failf(data, "Failed to receive SOCKS5 connect request ack."); return CURLE_COULDNT_CONNECT; } if(socksreq[0] != 5) { /* version */ failf(data, "SOCKS5 reply has wrong version, version should be 5."); return CURLE_COULDNT_CONNECT; } if(socksreq[1] != 0) { /* Anything besides 0 is an error */ failf(data, "Can't complete SOCKS5 connection to %d.%d.%d.%d:%d. (%d)", (unsigned char)socksreq[4], (unsigned char)socksreq[5], (unsigned char)socksreq[6], (unsigned char)socksreq[7], ((socksreq[8] << 8) | socksreq[9]), socksreq[1]); return CURLE_COULDNT_CONNECT; } /* Fix: in general, returned BND.ADDR is variable length parameter by RFC 1928, so the reply packet should be read until the end to avoid errors at subsequent protocol level. +----+-----+-------+------+----------+----------+ |VER | REP | RSV | ATYP | BND.ADDR | BND.PORT | +----+-----+-------+------+----------+----------+ | 1 | 1 | X'00' | 1 | Variable | 2 | +----+-----+-------+------+----------+----------+ ATYP: o IP v4 address: X'01', BND.ADDR = 4 byte o domain name: X'03', BND.ADDR = [ 1 byte length, string ] o IP v6 address: X'04', BND.ADDR = 16 byte */ /* Calculate real packet size */ if(socksreq[3] == 3) { /* domain name */ int addrlen = (int) socksreq[4]; packetsize = 5 + addrlen + 2; } else if(socksreq[3] == 4) { /* IPv6 */ packetsize = 4 + 16 + 2; } /* At this point we already read first 10 bytes */ #if defined(HAVE_GSSAPI) || defined(USE_WINDOWS_SSPI) if(!conn->socks5_gssapi_enctype) { /* decrypt_gssapi_blockread already read the whole packet */ #endif if(packetsize > 10) { packetsize -= 10; result = Curl_blockread_all(conn, sock, (char *)&socksreq[10], packetsize, &actualread); if((result != CURLE_OK) || (actualread != packetsize)) { failf(data, "Failed to receive SOCKS5 connect request ack."); return CURLE_COULDNT_CONNECT; } } #if defined(HAVE_GSSAPI) || defined(USE_WINDOWS_SSPI) } #endif curlx_nonblock(sock, TRUE); return CURLE_OK; /* Proxy was successful! */ } #endif /* CURL_DISABLE_PROXY */