| /*************************************************************************** |
| * _ _ ____ _ |
| * Project ___| | | | _ \| | |
| * / __| | | | |_) | | |
| * | (__| |_| | _ <| |___ |
| * \___|\___/|_| \_\_____| |
| * |
| * Copyright (C) Daniel Stenberg, <daniel@haxx.se>, 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 https://curl.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. |
| * |
| * SPDX-License-Identifier: curl |
| * |
| ***************************************************************************/ |
| |
| #include "curl_setup.h" |
| |
| #if !defined(CURL_DISABLE_PROXY) |
| |
| #ifdef HAVE_NETINET_IN_H |
| #include <netinet/in.h> |
| #endif |
| #ifdef HAVE_ARPA_INET_H |
| #include <arpa/inet.h> |
| #endif |
| |
| #include "urldata.h" |
| #include "sendf.h" |
| #include "select.h" |
| #include "cfilters.h" |
| #include "connect.h" |
| #include "timeval.h" |
| #include "socks.h" |
| #include "multiif.h" /* for getsock macros */ |
| #include "inet_pton.h" |
| #include "url.h" |
| |
| /* The last 3 #include files should be in this order */ |
| #include "curl_printf.h" |
| #include "curl_memory.h" |
| #include "memdebug.h" |
| |
| /* for the (SOCKS) connect state machine */ |
| enum connect_t { |
| CONNECT_INIT, |
| CONNECT_SOCKS_INIT, /* 1 */ |
| CONNECT_SOCKS_SEND, /* 2 waiting to send more first data */ |
| CONNECT_SOCKS_READ_INIT, /* 3 set up read */ |
| CONNECT_SOCKS_READ, /* 4 read server response */ |
| CONNECT_GSSAPI_INIT, /* 5 */ |
| CONNECT_AUTH_INIT, /* 6 setup outgoing auth buffer */ |
| CONNECT_AUTH_SEND, /* 7 send auth */ |
| CONNECT_AUTH_READ, /* 8 read auth response */ |
| CONNECT_REQ_INIT, /* 9 init SOCKS "request" */ |
| CONNECT_RESOLVING, /* 10 */ |
| CONNECT_RESOLVED, /* 11 */ |
| CONNECT_RESOLVE_REMOTE, /* 12 */ |
| CONNECT_REQ_SEND, /* 13 */ |
| CONNECT_REQ_SENDING, /* 14 */ |
| CONNECT_REQ_READ, /* 15 */ |
| CONNECT_REQ_READ_MORE, /* 16 */ |
| CONNECT_DONE /* 17 connected fine to the remote or the SOCKS proxy */ |
| }; |
| |
| #define CURL_SOCKS_BUF_SIZE 600 |
| |
| /* make sure we configure it not too low */ |
| #if CURL_SOCKS_BUF_SIZE < 600 |
| #error CURL_SOCKS_BUF_SIZE must be at least 600 |
| #endif |
| |
| |
| struct socks_state { |
| enum connect_t state; |
| ssize_t outstanding; /* send this many bytes more */ |
| unsigned char buffer[CURL_SOCKS_BUF_SIZE]; |
| unsigned char *outp; /* send from this pointer */ |
| |
| const char *hostname; |
| int remote_port; |
| const char *proxy_user; |
| const char *proxy_password; |
| }; |
| |
| #if defined(HAVE_GSSAPI) || defined(USE_WINDOWS_SSPI) |
| /* |
| * 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 behavior. Only used by the SOCKS GSSAPI functions. |
| */ |
| int Curl_blockread_all(struct Curl_cfilter *cf, |
| struct Curl_easy *data, /* transfer */ |
| char *buf, /* store read data here */ |
| ssize_t buffersize, /* max amount to read */ |
| ssize_t *n) /* amount bytes read */ |
| { |
| ssize_t nread = 0; |
| ssize_t allread = 0; |
| int result; |
| CURLcode err = CURLE_OK; |
| |
| *n = 0; |
| for(;;) { |
| timediff_t timeout_ms = Curl_timeleft(data, NULL, TRUE); |
| if(timeout_ms < 0) { |
| /* we already got the timeout */ |
| result = CURLE_OPERATION_TIMEDOUT; |
| break; |
| } |
| if(!timeout_ms) |
| timeout_ms = TIMEDIFF_T_MAX; |
| if(SOCKET_READABLE(cf->conn->sock[cf->sockindex], timeout_ms) <= 0) { |
| result = ~CURLE_OK; |
| break; |
| } |
| nread = Curl_conn_cf_recv(cf->next, data, buf, buffersize, &err); |
| if(nread <= 0) { |
| result = err; |
| if(CURLE_AGAIN == err) |
| continue; |
| if(err) { |
| 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; |
| } |
| #endif |
| |
| #if defined(DEBUGBUILD) && !defined(CURL_DISABLE_VERBOSE_STRINGS) |
| #define DEBUG_AND_VERBOSE |
| #define sxstate(x,d,y) socksstate(x,d,y, __LINE__) |
| #else |
| #define sxstate(x,d,y) socksstate(x,d,y) |
| #endif |
| |
| /* always use this function to change state, to make debugging easier */ |
| static void socksstate(struct socks_state *sx, struct Curl_easy *data, |
| enum connect_t state |
| #ifdef DEBUG_AND_VERBOSE |
| , int lineno |
| #endif |
| ) |
| { |
| enum connect_t oldstate = sx->state; |
| #ifdef DEBUG_AND_VERBOSE |
| /* synced with the state list in urldata.h */ |
| static const char * const socks_statename[] = { |
| "INIT", |
| "SOCKS_INIT", |
| "SOCKS_SEND", |
| "SOCKS_READ_INIT", |
| "SOCKS_READ", |
| "GSSAPI_INIT", |
| "AUTH_INIT", |
| "AUTH_SEND", |
| "AUTH_READ", |
| "REQ_INIT", |
| "RESOLVING", |
| "RESOLVED", |
| "RESOLVE_REMOTE", |
| "REQ_SEND", |
| "REQ_SENDING", |
| "REQ_READ", |
| "REQ_READ_MORE", |
| "DONE" |
| }; |
| #endif |
| |
| (void)data; |
| if(oldstate == state) |
| /* don't bother when the new state is the same as the old state */ |
| return; |
| |
| sx->state = state; |
| |
| #ifdef DEBUG_AND_VERBOSE |
| infof(data, |
| "SXSTATE: %s => %s; line %d", |
| socks_statename[oldstate], socks_statename[sx->state], |
| lineno); |
| #endif |
| } |
| |
| static CURLproxycode socks_state_send(struct Curl_cfilter *cf, |
| struct socks_state *sx, |
| struct Curl_easy *data, |
| CURLproxycode failcode, |
| const char *description) |
| { |
| ssize_t nwritten; |
| CURLcode result; |
| |
| nwritten = Curl_conn_cf_send(cf->next, data, (char *)sx->outp, |
| sx->outstanding, &result); |
| if(nwritten <= 0) { |
| if(CURLE_AGAIN == result) { |
| return CURLPX_OK; |
| } |
| else if(CURLE_OK == result) { |
| /* connection closed */ |
| failf(data, "connection to proxy closed"); |
| return CURLPX_CLOSED; |
| } |
| failf(data, "Failed to send %s: %s", description, |
| curl_easy_strerror(result)); |
| return failcode; |
| } |
| DEBUGASSERT(sx->outstanding >= nwritten); |
| /* not done, remain in state */ |
| sx->outstanding -= nwritten; |
| sx->outp += nwritten; |
| return CURLPX_OK; |
| } |
| |
| static CURLproxycode socks_state_recv(struct Curl_cfilter *cf, |
| struct socks_state *sx, |
| struct Curl_easy *data, |
| CURLproxycode failcode, |
| const char *description) |
| { |
| ssize_t nread; |
| CURLcode result; |
| |
| nread = Curl_conn_cf_recv(cf->next, data, (char *)sx->outp, |
| sx->outstanding, &result); |
| if(nread <= 0) { |
| if(CURLE_AGAIN == result) { |
| return CURLPX_OK; |
| } |
| else if(CURLE_OK == result) { |
| /* connection closed */ |
| failf(data, "connection to proxy closed"); |
| return CURLPX_CLOSED; |
| } |
| failf(data, "SOCKS: Failed receiving %s: %s", description, |
| curl_easy_strerror(result)); |
| return failcode; |
| } |
| /* remain in reading state */ |
| DEBUGASSERT(sx->outstanding >= nread); |
| sx->outstanding -= nread; |
| sx->outp += nread; |
| return CURLPX_OK; |
| } |
| |
| /* |
| * This function logs in to a SOCKS4 proxy and sends the specifics to the final |
| * destination server. |
| * |
| * Reference : |
| * https://www.openssh.com/txt/socks4.protocol |
| * |
| * Note : |
| * Set protocol4a=true for "SOCKS 4A (Simple Extension to SOCKS 4 Protocol)" |
| * Nonsupport "Identification Protocol (RFC1413)" |
| */ |
| static CURLproxycode do_SOCKS4(struct Curl_cfilter *cf, |
| struct socks_state *sx, |
| struct Curl_easy *data) |
| { |
| struct connectdata *conn = cf->conn; |
| const bool protocol4a = |
| (conn->socks_proxy.proxytype == CURLPROXY_SOCKS4A) ? TRUE : FALSE; |
| unsigned char *socksreq = sx->buffer; |
| CURLcode result; |
| CURLproxycode presult; |
| struct Curl_dns_entry *dns = NULL; |
| |
| switch(sx->state) { |
| case CONNECT_SOCKS_INIT: |
| /* SOCKS4 can only do IPv4, insist! */ |
| conn->ip_version = CURL_IPRESOLVE_V4; |
| if(conn->bits.httpproxy) |
| infof(data, "SOCKS4%s: connecting to HTTP proxy %s port %d", |
| protocol4a ? "a" : "", sx->hostname, sx->remote_port); |
| |
| infof(data, "SOCKS4 communication to %s:%d", |
| sx->hostname, sx->remote_port); |
| |
| /* |
| * 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)((sx->remote_port >> 8) & 0xff); /* MSB */ |
| socksreq[3] = (unsigned char)(sx->remote_port & 0xff); /* LSB */ |
| |
| /* DNS resolve only for SOCKS4, not SOCKS4a */ |
| if(!protocol4a) { |
| enum resolve_t rc = |
| Curl_resolv(data, sx->hostname, sx->remote_port, TRUE, &dns); |
| |
| if(rc == CURLRESOLV_ERROR) |
| return CURLPX_RESOLVE_HOST; |
| else if(rc == CURLRESOLV_PENDING) { |
| sxstate(sx, data, CONNECT_RESOLVING); |
| infof(data, "SOCKS4 non-blocking resolve of %s", sx->hostname); |
| return CURLPX_OK; |
| } |
| sxstate(sx, data, CONNECT_RESOLVED); |
| goto CONNECT_RESOLVED; |
| } |
| |
| /* socks4a doesn't resolve anything locally */ |
| sxstate(sx, data, CONNECT_REQ_INIT); |
| goto CONNECT_REQ_INIT; |
| |
| case CONNECT_RESOLVING: |
| /* check if we have the name resolved by now */ |
| dns = Curl_fetch_addr(data, sx->hostname, conn->primary.remote_port); |
| |
| if(dns) { |
| #ifdef CURLRES_ASYNCH |
| data->state.async.dns = dns; |
| data->state.async.done = TRUE; |
| #endif |
| infof(data, "Hostname '%s' was found", sx->hostname); |
| sxstate(sx, data, CONNECT_RESOLVED); |
| } |
| else { |
| result = Curl_resolv_check(data, &dns); |
| if(!dns) { |
| if(result) |
| return CURLPX_RESOLVE_HOST; |
| return CURLPX_OK; |
| } |
| } |
| FALLTHROUGH(); |
| case CONNECT_RESOLVED: |
| CONNECT_RESOLVED: |
| { |
| struct Curl_addrinfo *hp = NULL; |
| /* |
| * 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; |
| |
| /* scan for the first IPv4 address */ |
| while(hp && (hp->ai_family != AF_INET)) |
| hp = hp->ai_next; |
| |
| if(hp) { |
| struct sockaddr_in *saddr_in; |
| char buf[64]; |
| Curl_printable_address(hp, buf, sizeof(buf)); |
| |
| saddr_in = (struct sockaddr_in *)(void *)hp->ai_addr; |
| socksreq[4] = ((unsigned char *)&saddr_in->sin_addr.s_addr)[0]; |
| socksreq[5] = ((unsigned char *)&saddr_in->sin_addr.s_addr)[1]; |
| socksreq[6] = ((unsigned char *)&saddr_in->sin_addr.s_addr)[2]; |
| socksreq[7] = ((unsigned char *)&saddr_in->sin_addr.s_addr)[3]; |
| |
| infof(data, "SOCKS4 connect to IPv4 %s (locally resolved)", buf); |
| |
| Curl_resolv_unlock(data, dns); /* not used anymore from now on */ |
| } |
| else |
| failf(data, "SOCKS4 connection to %s not supported", sx->hostname); |
| } |
| else |
| failf(data, "Failed to resolve \"%s\" for SOCKS4 connect.", |
| sx->hostname); |
| |
| if(!hp) |
| return CURLPX_RESOLVE_HOST; |
| } |
| FALLTHROUGH(); |
| case CONNECT_REQ_INIT: |
| CONNECT_REQ_INIT: |
| /* |
| * This is currently not supporting "Identification Protocol (RFC1413)". |
| */ |
| socksreq[8] = 0; /* ensure empty userid is NUL-terminated */ |
| if(sx->proxy_user) { |
| size_t plen = strlen(sx->proxy_user); |
| if(plen > 255) { |
| /* there is no real size limit to this field in the protocol, but |
| SOCKS5 limits the proxy user field to 255 bytes and it seems likely |
| that a longer field is either a mistake or malicious input */ |
| failf(data, "Too long SOCKS proxy user name"); |
| return CURLPX_LONG_USER; |
| } |
| /* copy the proxy name WITH trailing zero */ |
| memcpy(socksreq + 8, sx->proxy_user, plen + 1); |
| } |
| |
| /* |
| * Make connection |
| */ |
| { |
| size_t packetsize = 9 + |
| strlen((char *)socksreq + 8); /* size including NUL */ |
| |
| /* If SOCKS4a, set special invalid IP address 0.0.0.x */ |
| if(protocol4a) { |
| size_t hostnamelen = 0; |
| socksreq[4] = 0; |
| socksreq[5] = 0; |
| socksreq[6] = 0; |
| socksreq[7] = 1; |
| /* append hostname */ |
| hostnamelen = strlen(sx->hostname) + 1; /* length including NUL */ |
| if((hostnamelen <= 255) && |
| (packetsize + hostnamelen < sizeof(sx->buffer))) |
| strcpy((char *)socksreq + packetsize, sx->hostname); |
| else { |
| failf(data, "SOCKS4: too long host name"); |
| return CURLPX_LONG_HOSTNAME; |
| } |
| packetsize += hostnamelen; |
| } |
| sx->outp = socksreq; |
| DEBUGASSERT(packetsize <= sizeof(sx->buffer)); |
| sx->outstanding = packetsize; |
| sxstate(sx, data, CONNECT_REQ_SENDING); |
| } |
| FALLTHROUGH(); |
| case CONNECT_REQ_SENDING: |
| /* Send request */ |
| presult = socks_state_send(cf, sx, data, CURLPX_SEND_CONNECT, |
| "SOCKS4 connect request"); |
| if(CURLPX_OK != presult) |
| return presult; |
| else if(sx->outstanding) { |
| /* remain in sending state */ |
| return CURLPX_OK; |
| } |
| /* done sending! */ |
| sx->outstanding = 8; /* receive data size */ |
| sx->outp = socksreq; |
| sxstate(sx, data, CONNECT_SOCKS_READ); |
| |
| FALLTHROUGH(); |
| case CONNECT_SOCKS_READ: |
| /* Receive response */ |
| presult = socks_state_recv(cf, sx, data, CURLPX_RECV_CONNECT, |
| "connect request ack"); |
| if(CURLPX_OK != presult) |
| return presult; |
| else if(sx->outstanding) { |
| /* remain in reading state */ |
| return CURLPX_OK; |
| } |
| sxstate(sx, data, CONNECT_DONE); |
| break; |
| default: /* lots of unused states in SOCKS4 */ |
| break; |
| } |
| |
| /* |
| * 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]) { |
| failf(data, |
| "SOCKS4 reply has wrong version, version should be 0."); |
| return CURLPX_BAD_VERSION; |
| } |
| |
| /* Result */ |
| switch(socksreq[1]) { |
| case 90: |
| infof(data, "SOCKS4%s request granted.", protocol4a?"a":""); |
| break; |
| case 91: |
| failf(data, |
| "Can't complete SOCKS4 connection to %d.%d.%d.%d:%d. (%d)" |
| ", request rejected or failed.", |
| socksreq[4], socksreq[5], socksreq[6], socksreq[7], |
| (((unsigned char)socksreq[2] << 8) | (unsigned char)socksreq[3]), |
| (unsigned char)socksreq[1]); |
| return CURLPX_REQUEST_FAILED; |
| 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.", |
| socksreq[4], socksreq[5], socksreq[6], socksreq[7], |
| (((unsigned char)socksreq[2] << 8) | (unsigned char)socksreq[3]), |
| (unsigned char)socksreq[1]); |
| return CURLPX_IDENTD; |
| 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.", |
| socksreq[4], socksreq[5], socksreq[6], socksreq[7], |
| (((unsigned char)socksreq[2] << 8) | (unsigned char)socksreq[3]), |
| (unsigned char)socksreq[1]); |
| return CURLPX_IDENTD_DIFFER; |
| default: |
| failf(data, |
| "Can't complete SOCKS4 connection to %d.%d.%d.%d:%d. (%d)" |
| ", Unknown.", |
| socksreq[4], socksreq[5], socksreq[6], socksreq[7], |
| (((unsigned char)socksreq[2] << 8) | (unsigned char)socksreq[3]), |
| (unsigned char)socksreq[1]); |
| return CURLPX_UNKNOWN_FAIL; |
| } |
| |
| return CURLPX_OK; /* Proxy was successful! */ |
| } |
| |
| /* |
| * This function logs in to a SOCKS5 proxy and sends the specifics to the final |
| * destination server. |
| */ |
| static CURLproxycode do_SOCKS5(struct Curl_cfilter *cf, |
| struct socks_state *sx, |
| struct Curl_easy *data) |
| { |
| /* |
| 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 |
| */ |
| struct connectdata *conn = cf->conn; |
| unsigned char *socksreq = sx->buffer; |
| size_t idx; |
| CURLcode result; |
| CURLproxycode presult; |
| bool socks5_resolve_local = |
| (conn->socks_proxy.proxytype == CURLPROXY_SOCKS5) ? TRUE : FALSE; |
| const size_t hostname_len = strlen(sx->hostname); |
| size_t len = 0; |
| const unsigned char auth = data->set.socks5auth; |
| bool allow_gssapi = FALSE; |
| struct Curl_dns_entry *dns = NULL; |
| |
| DEBUGASSERT(auth & (CURLAUTH_BASIC | CURLAUTH_GSSAPI)); |
| switch(sx->state) { |
| case CONNECT_SOCKS_INIT: |
| if(conn->bits.httpproxy) |
| infof(data, "SOCKS5: connecting to HTTP proxy %s port %d", |
| sx->hostname, sx->remote_port); |
| |
| /* RFC1928 chapter 5 specifies max 255 chars for domain name in packet */ |
| if(!socks5_resolve_local && hostname_len > 255) { |
| failf(data, "SOCKS5: the destination hostname is too long to be " |
| "resolved remotely by the proxy."); |
| return CURLPX_LONG_HOSTNAME; |
| } |
| |
| if(auth & ~(CURLAUTH_BASIC | CURLAUTH_GSSAPI)) |
| infof(data, |
| "warning: unsupported value passed to CURLOPT_SOCKS5_AUTH: %u", |
| auth); |
| if(!(auth & CURLAUTH_BASIC)) |
| /* disable username/password auth */ |
| sx->proxy_user = NULL; |
| #if defined(HAVE_GSSAPI) || defined(USE_WINDOWS_SSPI) |
| if(auth & CURLAUTH_GSSAPI) |
| allow_gssapi = TRUE; |
| #endif |
| |
| idx = 0; |
| socksreq[idx++] = 5; /* version */ |
| idx++; /* number of authentication methods */ |
| socksreq[idx++] = 0; /* no authentication */ |
| if(allow_gssapi) |
| socksreq[idx++] = 1; /* GSS-API */ |
| if(sx->proxy_user) |
| socksreq[idx++] = 2; /* username/password */ |
| /* write the number of authentication methods */ |
| socksreq[1] = (unsigned char) (idx - 2); |
| |
| sx->outp = socksreq; |
| DEBUGASSERT(idx <= sizeof(sx->buffer)); |
| sx->outstanding = idx; |
| presult = socks_state_send(cf, sx, data, CURLPX_SEND_CONNECT, |
| "initial SOCKS5 request"); |
| if(CURLPX_OK != presult) |
| return presult; |
| else if(sx->outstanding) { |
| /* remain in sending state */ |
| return CURLPX_OK; |
| } |
| sxstate(sx, data, CONNECT_SOCKS_READ); |
| goto CONNECT_SOCKS_READ_INIT; |
| case CONNECT_SOCKS_SEND: |
| presult = socks_state_send(cf, sx, data, CURLPX_SEND_CONNECT, |
| "initial SOCKS5 request"); |
| if(CURLPX_OK != presult) |
| return presult; |
| else if(sx->outstanding) { |
| /* remain in sending state */ |
| return CURLPX_OK; |
| } |
| FALLTHROUGH(); |
| case CONNECT_SOCKS_READ_INIT: |
| CONNECT_SOCKS_READ_INIT: |
| sx->outstanding = 2; /* expect two bytes */ |
| sx->outp = socksreq; /* store it here */ |
| FALLTHROUGH(); |
| case CONNECT_SOCKS_READ: |
| presult = socks_state_recv(cf, sx, data, CURLPX_RECV_CONNECT, |
| "initial SOCKS5 response"); |
| if(CURLPX_OK != presult) |
| return presult; |
| else if(sx->outstanding) { |
| /* remain in reading state */ |
| return CURLPX_OK; |
| } |
| else if(socksreq[0] != 5) { |
| failf(data, "Received invalid version in initial SOCKS5 response."); |
| return CURLPX_BAD_VERSION; |
| } |
| else if(socksreq[1] == 0) { |
| /* DONE! No authentication needed. Send request. */ |
| sxstate(sx, data, CONNECT_REQ_INIT); |
| goto CONNECT_REQ_INIT; |
| } |
| else if(socksreq[1] == 2) { |
| /* regular name + password authentication */ |
| sxstate(sx, data, CONNECT_AUTH_INIT); |
| goto CONNECT_AUTH_INIT; |
| } |
| #if defined(HAVE_GSSAPI) || defined(USE_WINDOWS_SSPI) |
| else if(allow_gssapi && (socksreq[1] == 1)) { |
| sxstate(sx, data, CONNECT_GSSAPI_INIT); |
| result = Curl_SOCKS5_gssapi_negotiate(cf, data); |
| if(result) { |
| failf(data, "Unable to negotiate SOCKS5 GSS-API context."); |
| return CURLPX_GSSAPI; |
| } |
| } |
| #endif |
| else { |
| /* error */ |
| if(!allow_gssapi && (socksreq[1] == 1)) { |
| failf(data, |
| "SOCKS5 GSSAPI per-message authentication is not supported."); |
| return CURLPX_GSSAPI_PERMSG; |
| } |
| else if(socksreq[1] == 255) { |
| failf(data, "No authentication method was acceptable."); |
| return CURLPX_NO_AUTH; |
| } |
| } |
| failf(data, |
| "Undocumented SOCKS5 mode attempted to be used by server."); |
| return CURLPX_UNKNOWN_MODE; |
| #if defined(HAVE_GSSAPI) || defined(USE_WINDOWS_SSPI) |
| case CONNECT_GSSAPI_INIT: |
| /* GSSAPI stuff done non-blocking */ |
| break; |
| #endif |
| |
| default: /* do nothing! */ |
| break; |
| |
| CONNECT_AUTH_INIT: |
| case CONNECT_AUTH_INIT: { |
| /* Needs user name and password */ |
| size_t proxy_user_len, proxy_password_len; |
| if(sx->proxy_user && sx->proxy_password) { |
| proxy_user_len = strlen(sx->proxy_user); |
| proxy_password_len = strlen(sx->proxy_password); |
| } |
| else { |
| proxy_user_len = 0; |
| proxy_password_len = 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) proxy_user_len; |
| if(sx->proxy_user && proxy_user_len) { |
| /* the length must fit in a single byte */ |
| if(proxy_user_len > 255) { |
| failf(data, "Excessive user name length for proxy auth"); |
| return CURLPX_LONG_USER; |
| } |
| memcpy(socksreq + len, sx->proxy_user, proxy_user_len); |
| } |
| len += proxy_user_len; |
| socksreq[len++] = (unsigned char) proxy_password_len; |
| if(sx->proxy_password && proxy_password_len) { |
| /* the length must fit in a single byte */ |
| if(proxy_password_len > 255) { |
| failf(data, "Excessive password length for proxy auth"); |
| return CURLPX_LONG_PASSWD; |
| } |
| memcpy(socksreq + len, sx->proxy_password, proxy_password_len); |
| } |
| len += proxy_password_len; |
| sxstate(sx, data, CONNECT_AUTH_SEND); |
| DEBUGASSERT(len <= sizeof(sx->buffer)); |
| sx->outstanding = len; |
| sx->outp = socksreq; |
| } |
| FALLTHROUGH(); |
| case CONNECT_AUTH_SEND: |
| presult = socks_state_send(cf, sx, data, CURLPX_SEND_AUTH, |
| "SOCKS5 sub-negotiation request"); |
| if(CURLPX_OK != presult) |
| return presult; |
| else if(sx->outstanding) { |
| /* remain in sending state */ |
| return CURLPX_OK; |
| } |
| sx->outp = socksreq; |
| sx->outstanding = 2; |
| sxstate(sx, data, CONNECT_AUTH_READ); |
| FALLTHROUGH(); |
| case CONNECT_AUTH_READ: |
| presult = socks_state_recv(cf, sx, data, CURLPX_RECV_AUTH, |
| "SOCKS5 sub-negotiation response"); |
| if(CURLPX_OK != presult) |
| return presult; |
| else if(sx->outstanding) { |
| /* remain in reading state */ |
| return CURLPX_OK; |
| } |
| /* ignore the first (VER) byte */ |
| else if(socksreq[1]) { /* status */ |
| failf(data, "User was rejected by the SOCKS5 server (%d %d).", |
| socksreq[0], socksreq[1]); |
| return CURLPX_USER_REJECTED; |
| } |
| |
| /* Everything is good so far, user was authenticated! */ |
| sxstate(sx, data, CONNECT_REQ_INIT); |
| FALLTHROUGH(); |
| case CONNECT_REQ_INIT: |
| CONNECT_REQ_INIT: |
| if(socks5_resolve_local) { |
| enum resolve_t rc = Curl_resolv(data, sx->hostname, sx->remote_port, |
| TRUE, &dns); |
| |
| if(rc == CURLRESOLV_ERROR) |
| return CURLPX_RESOLVE_HOST; |
| |
| if(rc == CURLRESOLV_PENDING) { |
| sxstate(sx, data, CONNECT_RESOLVING); |
| return CURLPX_OK; |
| } |
| sxstate(sx, data, CONNECT_RESOLVED); |
| goto CONNECT_RESOLVED; |
| } |
| goto CONNECT_RESOLVE_REMOTE; |
| |
| case CONNECT_RESOLVING: |
| /* check if we have the name resolved by now */ |
| dns = Curl_fetch_addr(data, sx->hostname, sx->remote_port); |
| |
| if(dns) { |
| #ifdef CURLRES_ASYNCH |
| data->state.async.dns = dns; |
| data->state.async.done = TRUE; |
| #endif |
| infof(data, "SOCKS5: hostname '%s' found", sx->hostname); |
| } |
| |
| if(!dns) { |
| result = Curl_resolv_check(data, &dns); |
| if(!dns) { |
| if(result) |
| return CURLPX_RESOLVE_HOST; |
| return CURLPX_OK; |
| } |
| } |
| FALLTHROUGH(); |
| case CONNECT_RESOLVED: |
| CONNECT_RESOLVED: |
| { |
| char dest[MAX_IPADR_LEN]; /* printable address */ |
| struct Curl_addrinfo *hp = NULL; |
| if(dns) |
| hp = dns->addr; |
| #ifdef ENABLE_IPV6 |
| if(data->set.ipver != CURL_IPRESOLVE_WHATEVER) { |
| int wanted_family = data->set.ipver == CURL_IPRESOLVE_V4 ? |
| AF_INET : AF_INET6; |
| /* scan for the first proper address */ |
| while(hp && (hp->ai_family != wanted_family)) |
| hp = hp->ai_next; |
| } |
| #endif |
| if(!hp) { |
| failf(data, "Failed to resolve \"%s\" for SOCKS5 connect.", |
| sx->hostname); |
| return CURLPX_RESOLVE_HOST; |
| } |
| |
| Curl_printable_address(hp, dest, sizeof(dest)); |
| |
| len = 0; |
| socksreq[len++] = 5; /* version (SOCKS5) */ |
| socksreq[len++] = 1; /* connect */ |
| socksreq[len++] = 0; /* must be zero */ |
| if(hp->ai_family == AF_INET) { |
| int i; |
| struct sockaddr_in *saddr_in; |
| socksreq[len++] = 1; /* ATYP: IPv4 = 1 */ |
| |
| saddr_in = (struct sockaddr_in *)(void *)hp->ai_addr; |
| for(i = 0; i < 4; i++) { |
| socksreq[len++] = ((unsigned char *)&saddr_in->sin_addr.s_addr)[i]; |
| } |
| |
| infof(data, "SOCKS5 connect to %s:%d (locally resolved)", dest, |
| sx->remote_port); |
| } |
| #ifdef ENABLE_IPV6 |
| else if(hp->ai_family == AF_INET6) { |
| int i; |
| struct sockaddr_in6 *saddr_in6; |
| socksreq[len++] = 4; /* ATYP: IPv6 = 4 */ |
| |
| saddr_in6 = (struct sockaddr_in6 *)(void *)hp->ai_addr; |
| for(i = 0; i < 16; i++) { |
| socksreq[len++] = |
| ((unsigned char *)&saddr_in6->sin6_addr.s6_addr)[i]; |
| } |
| |
| infof(data, "SOCKS5 connect to [%s]:%d (locally resolved)", dest, |
| sx->remote_port); |
| } |
| #endif |
| else { |
| hp = NULL; /* fail! */ |
| failf(data, "SOCKS5 connection to %s not supported", dest); |
| } |
| |
| Curl_resolv_unlock(data, dns); /* not used anymore from now on */ |
| goto CONNECT_REQ_SEND; |
| } |
| CONNECT_RESOLVE_REMOTE: |
| case CONNECT_RESOLVE_REMOTE: |
| /* Authentication is complete, now specify destination to the proxy */ |
| len = 0; |
| socksreq[len++] = 5; /* version (SOCKS5) */ |
| socksreq[len++] = 1; /* connect */ |
| socksreq[len++] = 0; /* must be zero */ |
| |
| if(!socks5_resolve_local) { |
| /* ATYP: domain name = 3, |
| IPv6 == 4, |
| IPv4 == 1 */ |
| unsigned char ip4[4]; |
| #ifdef ENABLE_IPV6 |
| if(conn->bits.ipv6_ip) { |
| char ip6[16]; |
| if(1 != Curl_inet_pton(AF_INET6, sx->hostname, ip6)) |
| return CURLPX_BAD_ADDRESS_TYPE; |
| socksreq[len++] = 4; |
| memcpy(&socksreq[len], ip6, sizeof(ip6)); |
| len += sizeof(ip6); |
| } |
| else |
| #endif |
| if(1 == Curl_inet_pton(AF_INET, sx->hostname, ip4)) { |
| socksreq[len++] = 1; |
| memcpy(&socksreq[len], ip4, sizeof(ip4)); |
| len += sizeof(ip4); |
| } |
| else { |
| socksreq[len++] = 3; |
| socksreq[len++] = (unsigned char) hostname_len; /* one byte length */ |
| memcpy(&socksreq[len], sx->hostname, hostname_len); /* w/o NULL */ |
| len += hostname_len; |
| } |
| infof(data, "SOCKS5 connect to %s:%d (remotely resolved)", |
| sx->hostname, sx->remote_port); |
| } |
| FALLTHROUGH(); |
| |
| case CONNECT_REQ_SEND: |
| CONNECT_REQ_SEND: |
| /* PORT MSB */ |
| socksreq[len++] = (unsigned char)((sx->remote_port >> 8) & 0xff); |
| /* PORT LSB */ |
| socksreq[len++] = (unsigned char)(sx->remote_port & 0xff); |
| |
| #if defined(HAVE_GSSAPI) || defined(USE_WINDOWS_SSPI) |
| if(conn->socks5_gssapi_enctype) { |
| failf(data, "SOCKS5 GSS-API protection not yet implemented."); |
| return CURLPX_GSSAPI_PROTECTION; |
| } |
| #endif |
| sx->outp = socksreq; |
| DEBUGASSERT(len <= sizeof(sx->buffer)); |
| sx->outstanding = len; |
| sxstate(sx, data, CONNECT_REQ_SENDING); |
| FALLTHROUGH(); |
| case CONNECT_REQ_SENDING: |
| presult = socks_state_send(cf, sx, data, CURLPX_SEND_REQUEST, |
| "SOCKS5 connect request"); |
| if(CURLPX_OK != presult) |
| return presult; |
| else if(sx->outstanding) { |
| /* remain in send state */ |
| return CURLPX_OK; |
| } |
| #if defined(HAVE_GSSAPI) || defined(USE_WINDOWS_SSPI) |
| if(conn->socks5_gssapi_enctype) { |
| failf(data, "SOCKS5 GSS-API protection not yet implemented."); |
| return CURLPX_GSSAPI_PROTECTION; |
| } |
| #endif |
| sx->outstanding = 10; /* minimum packet size is 10 */ |
| sx->outp = socksreq; |
| sxstate(sx, data, CONNECT_REQ_READ); |
| FALLTHROUGH(); |
| case CONNECT_REQ_READ: |
| presult = socks_state_recv(cf, sx, data, CURLPX_RECV_REQACK, |
| "SOCKS5 connect request ack"); |
| if(CURLPX_OK != presult) |
| return presult; |
| else if(sx->outstanding) { |
| /* remain in reading state */ |
| return CURLPX_OK; |
| } |
| else if(socksreq[0] != 5) { /* version */ |
| failf(data, |
| "SOCKS5 reply has wrong version, version should be 5."); |
| return CURLPX_BAD_VERSION; |
| } |
| else if(socksreq[1]) { /* Anything besides 0 is an error */ |
| CURLproxycode rc = CURLPX_REPLY_UNASSIGNED; |
| int code = socksreq[1]; |
| failf(data, "Can't complete SOCKS5 connection to %s. (%d)", |
| sx->hostname, (unsigned char)socksreq[1]); |
| if(code < 9) { |
| /* RFC 1928 section 6 lists: */ |
| static const CURLproxycode lookup[] = { |
| CURLPX_OK, |
| CURLPX_REPLY_GENERAL_SERVER_FAILURE, |
| CURLPX_REPLY_NOT_ALLOWED, |
| CURLPX_REPLY_NETWORK_UNREACHABLE, |
| CURLPX_REPLY_HOST_UNREACHABLE, |
| CURLPX_REPLY_CONNECTION_REFUSED, |
| CURLPX_REPLY_TTL_EXPIRED, |
| CURLPX_REPLY_COMMAND_NOT_SUPPORTED, |
| CURLPX_REPLY_ADDRESS_TYPE_NOT_SUPPORTED, |
| }; |
| rc = lookup[code]; |
| } |
| return rc; |
| } |
| |
| /* 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]; |
| len = 5 + addrlen + 2; |
| } |
| else if(socksreq[3] == 4) { |
| /* IPv6 */ |
| len = 4 + 16 + 2; |
| } |
| else if(socksreq[3] == 1) { |
| len = 4 + 4 + 2; |
| } |
| else { |
| failf(data, "SOCKS5 reply has wrong address type."); |
| return CURLPX_BAD_ADDRESS_TYPE; |
| } |
| |
| /* 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(len > 10) { |
| DEBUGASSERT(len <= sizeof(sx->buffer)); |
| sx->outstanding = len - 10; /* get the rest */ |
| sx->outp = &socksreq[10]; |
| sxstate(sx, data, CONNECT_REQ_READ_MORE); |
| } |
| else { |
| sxstate(sx, data, CONNECT_DONE); |
| break; |
| } |
| #if defined(HAVE_GSSAPI) || defined(USE_WINDOWS_SSPI) |
| } |
| #endif |
| FALLTHROUGH(); |
| case CONNECT_REQ_READ_MORE: |
| presult = socks_state_recv(cf, sx, data, CURLPX_RECV_ADDRESS, |
| "SOCKS5 connect request address"); |
| if(CURLPX_OK != presult) |
| return presult; |
| else if(sx->outstanding) { |
| /* remain in reading state */ |
| return CURLPX_OK; |
| } |
| sxstate(sx, data, CONNECT_DONE); |
| } |
| infof(data, "SOCKS5 request granted."); |
| |
| return CURLPX_OK; /* Proxy was successful! */ |
| } |
| |
| static CURLcode connect_SOCKS(struct Curl_cfilter *cf, |
| struct socks_state *sxstate, |
| struct Curl_easy *data) |
| { |
| CURLcode result = CURLE_OK; |
| CURLproxycode pxresult = CURLPX_OK; |
| struct connectdata *conn = cf->conn; |
| |
| switch(conn->socks_proxy.proxytype) { |
| case CURLPROXY_SOCKS5: |
| case CURLPROXY_SOCKS5_HOSTNAME: |
| pxresult = do_SOCKS5(cf, sxstate, data); |
| break; |
| |
| case CURLPROXY_SOCKS4: |
| case CURLPROXY_SOCKS4A: |
| pxresult = do_SOCKS4(cf, sxstate, data); |
| break; |
| |
| default: |
| failf(data, "unknown proxytype option given"); |
| result = CURLE_COULDNT_CONNECT; |
| } /* switch proxytype */ |
| if(pxresult) { |
| result = CURLE_PROXY; |
| data->info.pxcode = pxresult; |
| } |
| |
| return result; |
| } |
| |
| static void socks_proxy_cf_free(struct Curl_cfilter *cf) |
| { |
| struct socks_state *sxstate = cf->ctx; |
| if(sxstate) { |
| free(sxstate); |
| cf->ctx = NULL; |
| } |
| } |
| |
| /* After a TCP connection to the proxy has been verified, this function does |
| the next magic steps. If 'done' isn't set TRUE, it is not done yet and |
| must be called again. |
| |
| Note: this function's sub-functions call failf() |
| |
| */ |
| static CURLcode socks_proxy_cf_connect(struct Curl_cfilter *cf, |
| struct Curl_easy *data, |
| bool blocking, bool *done) |
| { |
| CURLcode result; |
| struct connectdata *conn = cf->conn; |
| int sockindex = cf->sockindex; |
| struct socks_state *sx = cf->ctx; |
| |
| if(cf->connected) { |
| *done = TRUE; |
| return CURLE_OK; |
| } |
| |
| result = cf->next->cft->do_connect(cf->next, data, blocking, done); |
| if(result || !*done) |
| return result; |
| |
| if(!sx) { |
| sx = calloc(1, sizeof(*sx)); |
| if(!sx) |
| return CURLE_OUT_OF_MEMORY; |
| cf->ctx = sx; |
| } |
| |
| if(sx->state == CONNECT_INIT) { |
| /* for the secondary socket (FTP), use the "connect to host" |
| * but ignore the "connect to port" (use the secondary port) |
| */ |
| sxstate(sx, data, CONNECT_SOCKS_INIT); |
| sx->hostname = |
| conn->bits.httpproxy ? |
| conn->http_proxy.host.name : |
| conn->bits.conn_to_host ? |
| conn->conn_to_host.name : |
| sockindex == SECONDARYSOCKET ? |
| conn->secondaryhostname : conn->host.name; |
| sx->remote_port = |
| conn->bits.httpproxy ? (int)conn->http_proxy.port : |
| sockindex == SECONDARYSOCKET ? conn->secondary_port : |
| conn->bits.conn_to_port ? conn->conn_to_port : |
| conn->remote_port; |
| sx->proxy_user = conn->socks_proxy.user; |
| sx->proxy_password = conn->socks_proxy.passwd; |
| } |
| |
| result = connect_SOCKS(cf, sx, data); |
| if(!result && sx->state == CONNECT_DONE) { |
| cf->connected = TRUE; |
| Curl_verboseconnect(data, conn, cf->sockindex); |
| socks_proxy_cf_free(cf); |
| } |
| |
| *done = cf->connected; |
| return result; |
| } |
| |
| static void socks_cf_adjust_pollset(struct Curl_cfilter *cf, |
| struct Curl_easy *data, |
| struct easy_pollset *ps) |
| { |
| struct socks_state *sx = cf->ctx; |
| |
| if(!cf->connected && sx) { |
| /* If we are not connected, the filter below is and has nothing |
| * to wait on, we determine what to wait for. */ |
| curl_socket_t sock = Curl_conn_cf_get_socket(cf, data); |
| switch(sx->state) { |
| case CONNECT_RESOLVING: |
| case CONNECT_SOCKS_READ: |
| case CONNECT_AUTH_READ: |
| case CONNECT_REQ_READ: |
| case CONNECT_REQ_READ_MORE: |
| Curl_pollset_set_in_only(data, ps, sock); |
| break; |
| default: |
| Curl_pollset_set_out_only(data, ps, sock); |
| break; |
| } |
| } |
| } |
| |
| static void socks_proxy_cf_close(struct Curl_cfilter *cf, |
| struct Curl_easy *data) |
| { |
| |
| DEBUGASSERT(cf->next); |
| cf->connected = FALSE; |
| socks_proxy_cf_free(cf); |
| cf->next->cft->do_close(cf->next, data); |
| } |
| |
| static void socks_proxy_cf_destroy(struct Curl_cfilter *cf, |
| struct Curl_easy *data) |
| { |
| (void)data; |
| socks_proxy_cf_free(cf); |
| } |
| |
| static void socks_cf_get_host(struct Curl_cfilter *cf, |
| struct Curl_easy *data, |
| const char **phost, |
| const char **pdisplay_host, |
| int *pport) |
| { |
| (void)data; |
| if(!cf->connected) { |
| *phost = cf->conn->socks_proxy.host.name; |
| *pdisplay_host = cf->conn->http_proxy.host.dispname; |
| *pport = (int)cf->conn->socks_proxy.port; |
| } |
| else { |
| cf->next->cft->get_host(cf->next, data, phost, pdisplay_host, pport); |
| } |
| } |
| |
| struct Curl_cftype Curl_cft_socks_proxy = { |
| "SOCKS-PROXYY", |
| CF_TYPE_IP_CONNECT, |
| 0, |
| socks_proxy_cf_destroy, |
| socks_proxy_cf_connect, |
| socks_proxy_cf_close, |
| socks_cf_get_host, |
| socks_cf_adjust_pollset, |
| Curl_cf_def_data_pending, |
| Curl_cf_def_send, |
| Curl_cf_def_recv, |
| Curl_cf_def_cntrl, |
| Curl_cf_def_conn_is_alive, |
| Curl_cf_def_conn_keep_alive, |
| Curl_cf_def_query, |
| }; |
| |
| CURLcode Curl_cf_socks_proxy_insert_after(struct Curl_cfilter *cf_at, |
| struct Curl_easy *data) |
| { |
| struct Curl_cfilter *cf; |
| CURLcode result; |
| |
| (void)data; |
| result = Curl_cf_create(&cf, &Curl_cft_socks_proxy, NULL); |
| if(!result) |
| Curl_conn_cf_insert_after(cf_at, cf); |
| return result; |
| } |
| |
| #endif /* CURL_DISABLE_PROXY */ |
