diff options
Diffstat (limited to 'Utilities/cmcurl/lib/socks.c')
| -rw-r--r-- | Utilities/cmcurl/lib/socks.c | 1263 |
1 files changed, 1263 insertions, 0 deletions
diff --git a/Utilities/cmcurl/lib/socks.c b/Utilities/cmcurl/lib/socks.c new file mode 100644 index 0000000..3a396de --- /dev/null +++ b/Utilities/cmcurl/lib/socks.c @@ -0,0 +1,1263 @@ +/*************************************************************************** + * _ _ ____ _ + * 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 */ +}; + +struct socks_state { + enum connect_t state; + ssize_t outstanding; /* send this many bytes more */ + 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, "SOCKS4: 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 = (unsigned char *)data->state.buffer; + CURLcode result; + CURLproxycode presult; + struct Curl_dns_entry *dns = NULL; + + /* make sure that the buffer is at least 600 bytes */ + DEBUGASSERT(READBUFFER_MIN >= 600); + + 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, (int)conn->port); + + if(dns) { +#ifdef CURLRES_ASYNCH + conn->resolve_async.dns = dns; + conn->resolve_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 */ +CONNECT_RESOLVED: + case 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 */ +CONNECT_REQ_INIT: + case 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 < data->set.buffer_size)) + strcpy((char *)socksreq + packetsize, sx->hostname); + else { + failf(data, "SOCKS4: too long host name"); + return CURLPX_LONG_HOSTNAME; + } + packetsize += hostnamelen; + } + sx->outp = socksreq; + 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 = (unsigned char *)data->state.buffer; + int 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); + ssize_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; + 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 */ +CONNECT_SOCKS_READ_INIT: + case 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); + 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 */ +CONNECT_REQ_INIT: + case 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 + conn->resolve_async.dns = dns; + conn->resolve_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 */ +CONNECT_RESOLVED: + case 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 */ + +CONNECT_REQ_SEND: + case 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; + 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) { + 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); + 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 */ |