--- /dev/null
+/***********************************************************************
+ * connect.c -- Make socket connection using SOCKS4/5 and HTTP tunnel.
+ *
+ * Copyright (c) 2000-2004 Shun-ichi Goto
+ * Copyright (c) 2002, J. Grant (English Corrections)
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+ *
+ * ---------------------------------------------------------
+ * PROJECT: My Test Program
+ * AUTHOR: Shun-ichi GOTO <gotoh@taiyo.co.jp>
+ * CREATE: Wed Jun 21, 2000
+ * REVISION: $Revision$
+ * ---------------------------------------------------------
+ *
+ * Getting Source
+ * ==============
+ *
+ * Recent version of 'connect.c' is available from
+ * http://www.taiyo.co.jp/~gotoh/ssh/connect.c
+ *
+ * Related tool, ssh-askpass.exe (alternative ssh-askpass on UNIX)
+ * is available:
+ * http://www.taiyo.co.jp/~gotoh/ssh/ssh-askpass.exe.gz
+ *
+ * See more detail:
+ * http://www.taiyo.co.jp/~gotoh/ssh/connect.html
+ *
+ * How To Compile
+ * ==============
+ *
+ * On UNIX environment:
+ * $ gcc connect.c -o connect
+ *
+ * On SOLARIS:
+ * $ gcc -o connect -lresolv -lsocket -lnsl connect.c
+ *
+ * on Win32 environment:
+ * $ cl connect.c wsock32.lib advapi32.lib
+ * or
+ * $ bcc32 connect.c wsock32.lib advapi32.lib
+ * or
+ * $ gcc connect.c -o connect
+ *
+ * on Mac OS X environment:
+ * $ gcc connect.c -o connect -lresolv
+ * or
+ * $ gcc connect.c -o connect -DBIND_8_COMPAT=1
+ *
+ * How To Use
+ * ==========
+ *
+ * You can specify proxy method in an environment variable or in a
+ * command line option.
+ *
+ * usage: connect [-dnhst45] [-R resolve] [-p local-port] [-w sec]
+ * [-H [user@]proxy-server[:port]]
+ * [-S [user@]socks-server[:port]]
+ * [-T proxy-server[:port]]
+ * [-c telnet proxy command]
+ * host port
+ *
+ * "host" and "port" is for the target hostname and port-number to
+ * connect to.
+ *
+ * The -H option specifys a hostname and port number of the http proxy
+ * server to relay. If port is omitted, 80 is used. You can specify this
+ * value in the environment variable HTTP_PROXY and pass the -h option
+ * to use it.
+ *
+ * The -S option specifys the hostname and port number of the SOCKS
+ * server to relay. Like -H, port number can be omitted and the default
+ * is 1080. You can also specify this value pair in the environment
+ * variable SOCKS5_SERVER and give the -s option to use it.
+ *
+ * The '-4' and the '-5' options are for specifying SOCKS relaying and
+ * indicates protocol version to use. It is valid only when used with
+ * '-s' or '-S'. Default is '-5' (protocol version 5)
+ *
+ * The '-R' option is for specifying method to resolve the
+ * hostname. Three keywords ("local", "remote", "both") or dot-notation
+ * IP address are acceptable. The keyword "both" means, "Try local
+ * first, then remote". If a dot-notation IP address is specified, use
+ * this host as nameserver. The default is "remote" for SOCKS5 or
+ * "local" for others. On SOCKS4 protocol, remote resolving method
+ * ("remote" and "both") requires protocol 4a supported server.
+ *
+ * The '-p' option will forward a local TCP port instead of using the
+ * standard input and output.
+ *
+ * The '-P' option is same to '-p' except keep remote session. The
+ * program repeats waiting the port with holding remote session without
+ * disconnecting. To disconnect the remote session, send EOF to stdin or
+ * kill the program.
+ *
+ * The '-w' option specifys timeout seconds for making connection with
+ * TARGET host.
+ *
+ * The '-d' option is used for debug. If you fail to connect, use this
+ * and check request to and response from server.
+ *
+ * You can omit the "port" argument when program name is special format
+ * containing port number itself. For example,
+ * $ ln -s connect connect-25
+ * means this connect-25 command is spcifying port number 25 already
+ * so you need not 2nd argument (and ignored if specified).
+ *
+ * To use proxy, this example is for SOCKS5 connection to connect to
+ * 'host' at port 25 via SOCKS5 server on 'firewall' host.
+ * $ connect -S firewall host 25
+ * or
+ * $ SOCKS5_SERVER=firewall; export SOCKS5_SERVER
+ * $ connect -s host 25
+ *
+ * For a HTTP-PROXY connection:
+ * $ connect -H proxy-server:8080 host 25
+ * or
+ * $ HTTP_PROXY=proxy-server:8080; export HTTP_PROXY
+ * $ connect -h host 25
+ * To forward a local port, for example to use ssh:
+ * $ connect -p 5550 -H proxy-server:8080 host 22
+ * ($ ssh -l user -p 5550 localhost )
+ *
+ * TIPS
+ * ====
+ *
+ * Connect.c doesn't have any configuration to specify the SOCKS server.
+ * If you are a mobile user, this limitation might bother you. However,
+ * You can compile connect.c and link with other standard SOCKS library
+ * like the NEC SOCKS5 library or Dante. This means connect.c is
+ * socksified and uses a configration file like to other SOCKSified
+ * network commands and you can switch configuration file any time
+ * (ex. when ppp startup) that brings you switching of SOCKS server for
+ * connect.c in same way with other commands. For this case, you can
+ * write ~/.ssh/config like this:
+ *
+ * ProxyCommand connect -n %h %p
+ *
+ * SOCKS5 authentication
+ * =====================
+ *
+ * Only USER/PASS authentication is supported.
+ *
+ * Proxy authentication
+ * ====================
+ *
+ * Only BASIC scheme is supported.
+ *
+ * Authentication informations
+ * ===========================
+ *
+ * User name for authentication is specifed by an environment variable
+ * or system login name. And password is specified from environment
+ * variable or external program (specified in $SSH_ASKPASS) or tty.
+ *
+ * Following environment variable is used for specifying user name.
+ * SOCKS: $SOCKS5_USER, $LOGNAME, $USER
+ * HTTP Proxy: $HTTP_PROXY_USER, $LOGNAME, $USER
+ *
+ * ssh-askpass support
+ * ===================
+ *
+ * You can use ssh-askpass (came from OpenSSH or else) to specify
+ * password on graphical environment (X-Window or MS Windows). To use
+ * this, set program name to environment variable SSH_ASKPASS. On UNIX,
+ * X-Window must be required, so $DISPLAY environment variable is also
+ * needed. On Win32 environment, $DISPLAY is not mentioned.
+ *
+ * Related Informations
+ * ====================
+ *
+ * SOCKS5 -- RFC 1928, RFC 1929, RFC 1961
+ * NEC SOCKS Reference Implementation is available from:
+ * http://www.socks.nec.com
+ * DeleGate version 5 or earlier can be SOCKS4 server,
+ * and version 6 can be SOCKS5 and SOCKS4 server.
+ * and version 7.7.0 or later can be SOCKS5 and SOCKS4a server.
+ * http://www.delegate.org/delegate/
+ *
+ * HTTP-Proxy --
+ * Many http proxy servers supports this, but https should
+ * be allowed as configuration on your host.
+ * For example on DeleGate, you should add "https" to the
+ * "REMITTABLE" parameter to allow HTTP-Proxy like this:
+ * delegated -Pxxxx ...... REMITTABLE="+,https" ...
+ *
+ * Hypertext Transfer Protocol -- HTTP/1.1 -- RFC 2616
+ * HTTP Authentication: Basic and Digest Access Authentication -- RFC 2617
+ * For proxy authentication, refer these documents.
+ *
+ ***********************************************************************/
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <ctype.h>
+#include <memory.h>
+#include <errno.h>
+#include <assert.h>
+#include <sys/types.h>
+#include <stdarg.h>
+#include <fcntl.h>
+#include <signal.h>
+
+#ifdef __CYGWIN32__
+#undef _WIN32
+#endif
+
+#ifdef _WIN32
+#include <windows.h>
+#include <winsock.h>
+#include <sys/stat.h>
+#include <io.h>
+#include <conio.h>
+#else /* !_WIN32 */
+#include <unistd.h>
+#include <pwd.h>
+#include <termios.h>
+#include <sys/time.h>
+#ifndef __hpux
+#include <sys/select.h>
+#endif /* __hpux */
+#include <sys/socket.h>
+#include <netinet/in.h>
+#include <arpa/inet.h>
+#include <netdb.h>
+#if !defined(_WIN32) && !defined(__CYGWIN32__)
+#define WITH_RESOLVER 1
+#include <arpa/nameser.h>
+#include <resolv.h>
+#else /* not ( not _WIN32 && not __CYGWIN32__) */
+#undef WITH_RESOLVER
+#endif /* not ( not _WIN32 && not __CYGWIN32__) */
+#endif /* !_WIN32 */
+
+#ifdef _WIN32
+#define ECONNRESET WSAECONNRESET
+#endif /* _WI32 */
+
+
+
+#ifndef LINT
+static char *vcid = "$Id$";
+#endif
+
+/* Microsoft Visual C/C++ has _snprintf() and _vsnprintf() */
+#ifdef _MSC_VER
+#define snprintf _snprintf
+#define vsnprintf _vsnprintf
+#endif
+
+/* consider Borland C */
+#ifdef __BORLANDC__
+#define _kbhit kbhit
+#define _setmode setmode
+#endif
+
+/* help message.
+ Win32 environment does not support -R option (vc and cygwin)
+ Win32 native compilers does not support -w option, yet (vc)
+*/
+static char *usage = "usage: %s [-dnhst45] [-p local-port]"
+#ifdef _WIN32
+#ifdef __CYGWIN32__
+"[-w timeout] \n" /* cygwin cannot -R */
+#else /* not __CYGWIN32__ */
+" \n" /* VC cannot -w nor -R */
+#endif /* not __CYGWIN32__ */
+#else /* not _WIN32 */
+/* help message for UNIX */
+"[-R resolve] [-w timeout] \n"
+#endif /* not _WIN32 */
+" [-H proxy-server[:port]] [-S [user@]socks-server[:port]] \n"
+" [-T proxy-server[:port]]\n"
+" [-c telnet-proxy-command]\n"
+" host port\n";
+
+/* name of this program */
+char *progname = NULL;
+char *progdesc = "connect --- simple relaying command via proxy.";
+char *rcs_revstr = "$Revision$";
+char *revstr = NULL;
+
+/* set of character for strspn() */
+const char *digits = "0123456789";
+const char *dotdigits = "0123456789.";
+
+/* options */
+int f_debug = 0;
+
+/* report flag to hide secure information */
+int f_report = 1;
+
+int connect_timeout = 0;
+
+/* local input type */
+#define LOCAL_STDIO 0
+#define LOCAL_SOCKET 1
+char *local_type_names[] = { "stdio", "socket" };
+int local_type = LOCAL_STDIO;
+u_short local_port = 0; /* option 'p' */
+int f_hold_session = 0; /* option 'P' */
+
+char *telnet_command = "telnet %h %p";
+
+/* utiity types, pair holder of number and string */
+typedef struct {
+ int num;
+ const char *str;
+} LOOKUP_ITEM;
+
+/* relay method, server and port */
+#define METHOD_UNDECIDED 0
+#define METHOD_DIRECT 1
+#define METHOD_SOCKS 2
+#define METHOD_HTTP 3
+#define METHOD_TELNET 4
+char *method_names[] = { "UNDECIDED", "DIRECT", "SOCKS", "HTTP", "TELNET" };
+
+int relay_method = METHOD_UNDECIDED; /* relaying method */
+char *relay_host = NULL; /* hostname of relay server */
+u_short relay_port = 0; /* port of relay server */
+char *relay_user = NULL; /* user name for auth */
+
+/* destination target host and port */
+char *dest_host = NULL;
+struct sockaddr_in dest_addr;
+u_short dest_port = 0;
+
+/* informations for SOCKS */
+#define SOCKS5_REP_SUCCEEDED 0x00 /* succeeded */
+#define SOCKS5_REP_FAIL 0x01 /* general SOCKS serer failure */
+#define SOCKS5_REP_NALLOWED 0x02 /* connection not allowed by ruleset */
+#define SOCKS5_REP_NUNREACH 0x03 /* Network unreachable */
+#define SOCKS5_REP_HUNREACH 0x04 /* Host unreachable */
+#define SOCKS5_REP_REFUSED 0x05 /* connection refused */
+#define SOCKS5_REP_EXPIRED 0x06 /* TTL expired */
+#define SOCKS5_REP_CNOTSUP 0x07 /* Command not supported */
+#define SOCKS5_REP_ANOTSUP 0x08 /* Address not supported */
+#define SOCKS5_REP_INVADDR 0x09 /* Inalid address */
+
+LOOKUP_ITEM socks5_rep_names[] = {
+ { SOCKS5_REP_SUCCEEDED, "succeeded"},
+ { SOCKS5_REP_FAIL, "general SOCKS server failure"},
+ { SOCKS5_REP_NALLOWED, "connection not allowed by ruleset"},
+ { SOCKS5_REP_NUNREACH, "Network unreachable"},
+ { SOCKS5_REP_HUNREACH, "Host unreachable"},
+ { SOCKS5_REP_REFUSED, "connection refused"},
+ { SOCKS5_REP_EXPIRED, "TTL expired"},
+ { SOCKS5_REP_CNOTSUP, "Command not supported"},
+ { SOCKS5_REP_ANOTSUP, "Address not supported"},
+ { SOCKS5_REP_INVADDR, "Invalid address"},
+ { -1, NULL }
+};
+
+/* SOCKS5 authentication methods */
+#define SOCKS5_AUTH_REJECT 0xFF /* No acceptable auth method */
+#define SOCKS5_AUTH_NOAUTH 0x00 /* without authentication */
+#define SOCKS5_AUTH_GSSAPI 0x01 /* GSSAPI */
+#define SOCKS5_AUTH_USERPASS 0x02 /* User/Password */
+#define SOCKS5_AUTH_CHAP 0x03 /* Challenge-Handshake Auth Proto. */
+#define SOCKS5_AUTH_EAP 0x05 /* Extensible Authentication Proto. */
+#define SOCKS5_AUTH_MAF 0x08 /* Multi-Authentication Framework */
+
+#define SOCKS4_REP_SUCCEEDED 90 /* rquest granted (succeeded) */
+#define SOCKS4_REP_REJECTED 91 /* request rejected or failed */
+#define SOCKS4_REP_IDENT_FAIL 92 /* cannot connect identd */
+#define SOCKS4_REP_USERID 93 /* user id not matched */
+
+LOOKUP_ITEM socks4_rep_names[] = {
+ { SOCKS4_REP_SUCCEEDED, "request granted (succeeded)"},
+ { SOCKS4_REP_REJECTED, "request rejected or failed"},
+ { SOCKS4_REP_IDENT_FAIL, "cannot connect identd"},
+ { SOCKS4_REP_USERID, "user id not matched"},
+ { -1, NULL }
+};
+
+#define RESOLVE_UNKNOWN 0
+#define RESOLVE_LOCAL 1
+#define RESOLVE_REMOTE 2
+#define RESOLVE_BOTH 3
+char *resolve_names[] = { "UNKNOWN", "LOCAL", "REMOTE", "BOTH" };
+
+int socks_version = 5; /* SOCKS protocol version */
+int socks_resolve = RESOLVE_UNKNOWN;
+struct sockaddr_in socks_ns;
+char *socks5_auth = NULL;
+
+/* Environment variable names */
+#define ENV_SOCKS_SERVER "SOCKS_SERVER" /* SOCKS server */
+#define ENV_SOCKS5_SERVER "SOCKS5_SERVER"
+#define ENV_SOCKS4_SERVER "SOCKS4_SERVER"
+
+#define ENV_SOCKS_RESOLVE "SOCKS_RESOLVE" /* resolve method */
+#define ENV_SOCKS5_RESOLVE "SOCKS5_RESOLVE"
+#define ENV_SOCKS4_RESOLVE "SOCKS4_RESOLVE"
+
+#define ENV_SOCKS5_USER "SOCKS5_USER" /* auth user for SOCKS5 */
+#define ENV_SOCKS4_USER "SOCKS4_USER" /* auth user for SOCKS4 */
+#define ENV_SOCKS_USER "SOCKS_USER" /* auth user for SOCKS */
+#define ENV_SOCKS5_PASSWD "SOCKS5_PASSWD" /* auth password for SOCKS5 */
+#define ENV_SOCKS5_PASSWORD "SOCKS5_PASSWORD" /* old style */
+
+#define ENV_HTTP_PROXY "HTTP_PROXY" /* common env var */
+#define ENV_HTTP_PROXY_USER "HTTP_PROXY_USER" /* auth user */
+#define ENV_HTTP_PROXY_PASSWORD "HTTP_PROXY_PASSWORD" /* auth password */
+
+#define ENV_TELNET_PROXY "TELNET_PROXY" /* common env var */
+
+#define ENV_CONNECT_USER "CONNECT_USER" /* default auth user name */
+#define ENV_CONNECT_PASSWORD "CONNECT_PASSWORD" /* default auth password */
+
+#define ENV_SOCKS_DIRECT "SOCKS_DIRECT" /* addr-list for non-proxy */
+#define ENV_SOCKS5_DIRECT "SOCKS5_DIRECT"
+#define ENV_SOCKS4_DIRECT "SOCKS4_DIRECT"
+#define ENV_HTTP_DIRECT "HTTP_DIRECT"
+#define ENV_CONNECT_DIRECT "CONNECT_DIRECT"
+
+#define ENV_SOCKS5_AUTH "SOCKS5_AUTH"
+#define ENV_SSH_ASKPASS "SSH_ASKPASS" /* askpass program */
+
+/* Prefix string of HTTP_PROXY */
+#define HTTP_PROXY_PREFIX "http://"
+#define PROXY_AUTH_NONE 0
+#define PROXY_AUTH_BASIC 1
+#define PROXY_AUTH_DIGEST 2
+int proxy_auth_type = PROXY_AUTH_NONE;
+
+/* reason of end repeating */
+#define REASON_UNK -2
+#define REASON_ERROR -1
+#define REASON_CLOSED_BY_LOCAL 0
+#define REASON_CLOSED_BY_REMOTE 1
+
+/* return value of relay start function. */
+#define START_ERROR -1
+#define START_OK 0
+#define START_RETRY 1
+
+/* socket related definitions */
+#ifndef _WIN32
+#define SOCKET int
+#endif
+#ifndef SOCKET_ERROR
+#define SOCKET_ERROR -1
+#endif
+
+#ifdef _WIN32
+#define socket_errno() WSAGetLastError()
+#else /* !_WIN32 */
+#define closesocket close
+#define socket_errno() (errno)
+#endif /* !_WIN32 */
+
+#ifdef _WIN32
+#define popen _popen
+#endif /* WIN32 */
+
+/* packet operation macro */
+#define PUT_BYTE(ptr,data) (*(unsigned char*)ptr = data)
+
+/* debug message output */
+void
+debug( const char *fmt, ... )
+{
+ va_list args;
+ if ( f_debug ) {
+ va_start( args, fmt );
+ fprintf(stderr, "DEBUG: ");
+ vfprintf( stderr, fmt, args );
+ va_end( args );
+ }
+}
+
+void
+debug_( const char *fmt, ... ) /* without prefix */
+{
+ va_list args;
+ if ( f_debug ) {
+ va_start( args, fmt );
+ vfprintf( stderr, fmt, args );
+ va_end( args );
+ }
+}
+
+/* error message output */
+void
+error( const char *fmt, ... )
+{
+ va_list args;
+ va_start( args, fmt );
+ fprintf(stderr, "ERROR: ");
+ vfprintf( stderr, fmt, args );
+ va_end( args );
+}
+
+void
+fatal( const char *fmt, ... )
+{
+ va_list args;
+ va_start( args, fmt );
+ fprintf(stderr, "FATAL: ");
+ vfprintf( stderr, fmt, args );
+ va_end( args );
+ exit (EXIT_FAILURE);
+}
+
+
+void *
+xmalloc (size_t size)
+{
+ void *ret = malloc(size);
+ if (ret == NULL)
+ fatal("Cannot allocate memory: %d bytes.\n", size);
+ return ret;
+}
+
+void
+downcase( char *buf )
+{
+ while ( *buf ) {
+ if ( isupper(*buf) )
+ *buf += 'a'-'A';
+ buf++;
+ }
+}
+
+char *
+expand_host_and_port (const char *fmt, const char *host, int port)
+{
+ const char *src;
+ char *buf, *dst, *ptr;
+ size_t len = strlen(fmt) + strlen(host) + 20;
+ buf = xmalloc (len);
+ dst = buf;
+ src = fmt;
+
+ while (*src) {
+ if (*src == '%') {
+ switch (src[1]) {
+ case 'h':
+ strcpy (dst, host);
+ src += 2;
+ break;
+ case 'p':
+ snprintf (dst, len, "%d", port);
+ src += 2;
+ break;
+ default:
+ src ++;
+ break;
+ }
+ dst = buf + strlen (buf);
+ } else if (*src == '\\') {
+ switch (src[1]) {
+ case 'r': /* CR */
+ *dst++ = '\r';
+ src += 2;
+ break;
+ case 'n': /* LF */
+ *dst++ = '\n';
+ src += 2;
+ break;
+ case 't': /* TAB */
+ *dst++ = '\t';
+ src += 2;
+ break;
+ default:
+ src ++;
+ break;
+ }
+ } else {
+ /* usual */
+ *dst++ = *src++;
+ }
+ *dst = '\0';
+ }
+ assert (strlen(buf) < len);
+ return buf;
+}
+
+
+int
+lookup_resolve( const char *str )
+{
+ char *buf = strdup( str );
+ int ret;
+
+ downcase( buf );
+ if ( strcmp( buf, "both" ) == 0 )
+ ret = RESOLVE_BOTH;
+ else if ( strcmp( buf, "remote" ) == 0 )
+ ret = RESOLVE_REMOTE;
+ else if ( strcmp( buf, "local" ) == 0 )
+ ret = RESOLVE_LOCAL;
+ else if ( strspn(buf, dotdigits) == strlen(buf) ) {
+#ifndef WITH_RESOLVER
+ fatal("Sorry, you can't specify to resolve the hostname with the -R option on Win32 environment.");
+#endif /* not WITH_RESOLVER */
+ ret = RESOLVE_LOCAL; /* this case is also 'local' */
+ socks_ns.sin_addr.s_addr = inet_addr(buf);
+ socks_ns.sin_family = AF_INET;
+ }
+ else
+ ret = RESOLVE_UNKNOWN;
+ free(buf);
+ return ret;
+}
+
+char *
+getusername(void)
+{
+#ifdef _WIN32
+ static char buf[1024];
+ DWORD size = sizeof(buf);
+ buf[0] = '\0';
+ GetUserName( buf, &size);
+ return buf;
+#else /* not _WIN32 */
+ struct passwd *pw = getpwuid(getuid());
+ if ( pw == NULL )
+ fatal("getpwuid() failed for uid: %d\n", getuid());
+ return pw->pw_name;
+#endif /* not _WIN32 */
+}
+
+/* expect
+ check STR is begin with substr with case-ignored comparison.
+ Return 1 if matched, otherwise 0.
+*/
+int
+expect( char *str, char *substr)
+{
+ int len = strlen(substr);
+ while ( 0 < len-- ) {
+ if ( toupper(*str) != toupper(*substr) )
+ return 0; /* not matched */
+ str++, substr++;
+ }
+ return 1; /* good, matched */
+}
+
+
+/** PARAMETER operation **/
+#define PARAMETER_FILE "/etc/connectrc"
+#define PARAMETER_DOTFILE ".connectrc"
+typedef struct {
+ char* name;
+ char* value;
+} PARAMETER_ITEM;
+PARAMETER_ITEM parameter_table[] = {
+ { ENV_SOCKS_SERVER, NULL },
+ { ENV_SOCKS5_SERVER, NULL },
+ { ENV_SOCKS4_SERVER, NULL },
+ { ENV_SOCKS_RESOLVE, NULL },
+ { ENV_SOCKS5_RESOLVE, NULL },
+ { ENV_SOCKS4_RESOLVE, NULL },
+ { ENV_SOCKS5_USER, NULL },
+ { ENV_SOCKS5_PASSWD, NULL },
+ { ENV_SOCKS5_PASSWORD, NULL },
+ { ENV_HTTP_PROXY, NULL },
+ { ENV_HTTP_PROXY_USER, NULL },
+ { ENV_HTTP_PROXY_PASSWORD, NULL },
+ { ENV_CONNECT_USER, NULL },
+ { ENV_CONNECT_PASSWORD, NULL },
+ { ENV_SSH_ASKPASS, NULL },
+ { ENV_SOCKS5_DIRECT, NULL },
+ { ENV_SOCKS4_DIRECT, NULL },
+ { ENV_SOCKS_DIRECT, NULL },
+ { ENV_HTTP_DIRECT, NULL },
+ { ENV_CONNECT_DIRECT, NULL },
+ { ENV_SOCKS5_AUTH, NULL },
+ { NULL, NULL }
+};
+
+PARAMETER_ITEM*
+find_parameter_item(const char* name)
+{
+ int i;
+ for( i = 0; parameter_table[i].name != NULL; i++ ){
+ if ( strcmp(name, parameter_table[i].name) == 0 )
+ return ¶meter_table[i];
+ }
+ return NULL;
+}
+
+void
+read_parameter_file_1(const char* name)
+{
+ FILE* f;
+ int line;
+ char lbuf[1025];
+ f = fopen(name, "r");
+ if( f ){
+ debug("Reading parameter file(%s)\n", name);
+ for ( line = 1; fgets(lbuf, 1024, f); line++ ) {
+ char *p, *q, *param, *value;
+ p = strchr(lbuf, '\n');
+ if ( p == NULL )
+ fatal("%s:%d: buffer overflow\n", name, line);
+ *p = '\0';
+ p = strchr(lbuf, '#');
+ if ( p )
+ *p = '\0';
+ for ( p = lbuf; *p; p++ )
+ if( *p != ' ' && *p != '\t' ) break;
+ if ( *p == '\0' ) continue;
+ param = p;
+ p = strchr(p, '=');
+ if ( p == NULL ) {
+ error("%s:%d: missing equal sign\n", name, line);
+ continue;
+ }
+ for ( q = p - 1; q >= lbuf; q-- )
+ if ( *q != ' ' && *q != '\t' ) break;
+ *++q = '\0';
+ for ( ++p; *p; p++ )
+ if ( *p != ' ' && *p != '\t' ) break;
+ value = p;
+ for ( ; *p; p++ );
+ for ( p--; p >= lbuf; p-- )
+ if ( *p != ' ' && *p != '\t' ) break;
+ *++p = '\0';
+ if ( param && value ) {
+ PARAMETER_ITEM *item;
+ item = find_parameter_item(param);
+ if ( item == NULL ) {
+ error("%s:%d: unknown parameter `%s'\n", name, line, param);
+ continue;
+ }
+ item->value = strdup(value);
+ debug("Parameter `%s' is set to `%s'\n", param, value);
+ }
+ }
+ }
+}
+
+void
+read_parameter_file(void)
+{
+#if !defined(_WIN32) || defined(cygwin)
+ char *name;
+ struct passwd *pw;
+#endif
+
+ read_parameter_file_1(PARAMETER_FILE);
+#if !defined(_WIN32) || defined(cygwin)
+ pw = getpwuid(getuid());
+ if ( pw == NULL )
+ fatal("getpwuid() failed for uid: %d\n", getuid());
+ name = xmalloc(strlen(pw->pw_dir) + strlen(PARAMETER_DOTFILE) + 2);
+ strcpy(name, pw->pw_dir);
+ strcat(name, "/" PARAMETER_DOTFILE);
+ read_parameter_file_1(name);
+ free(name);
+#endif /* _WIN32 */
+}
+
+char*
+getparam(const char* name)
+{
+ char *value = getenv(name);
+ if ( value == NULL ){
+ PARAMETER_ITEM *item = find_parameter_item(name);
+ if ( item != NULL )
+ value = item->value;
+ }
+ return value;
+}
+
+
+/** DIRECT connection **/
+#define MAX_DIRECT_ADDR_LIST 256
+
+struct ADDRPAIR {
+ struct in_addr addr;
+ struct in_addr mask;
+ int negative;
+};
+
+struct ADDRPAIR direct_addr_list[MAX_DIRECT_ADDR_LIST];
+int n_direct_addr_list = 0;
+
+void
+mask_addr (void *addr, void *mask, int addrlen)
+{
+ char *a, *m;
+ a = addr;
+ m = mask;
+ while ( 0 < addrlen-- )
+ *a++ &= *m++;
+}
+
+int
+add_direct_addr (struct in_addr *addr, struct in_addr *mask, int negative)
+{
+ struct in_addr iaddr;
+ char *s;
+ if ( MAX_DIRECT_ADDR_LIST <= n_direct_addr_list ) {
+ error("direct address table is full!\n");
+ return -1;
+ }
+ iaddr = *addr;
+ mask_addr(&iaddr, mask, sizeof(iaddr));
+ s = strdup(inet_ntoa(iaddr));
+ debug("adding direct address entry: %s/%s\n", s, inet_ntoa(*mask));
+ free(s);
+ memcpy( &direct_addr_list[n_direct_addr_list].addr,
+ &iaddr, sizeof(iaddr));
+ memcpy( &direct_addr_list[n_direct_addr_list].mask,
+ mask, sizeof(*mask));
+ direct_addr_list[n_direct_addr_list].negative = negative;
+ n_direct_addr_list++;
+ return 0;
+}
+
+int
+parse_addr_pair (const char *str, struct in_addr *addr, struct in_addr *mask)
+{
+ /* NOTE: */
+ /* Assume already be splitted by separator
+ and formatted as folowing:
+ 1) 12.34.56.789/255.255.255.0
+ 2) 12.34.56.789/24
+ 3) 12.34.56.
+ All above generates same addr/mask pair 12.34.56.0 and 255.255.255.0
+ */
+ const char *ptr;
+ u_char *dsta, *dstm;
+ int i, n;
+
+ assert( str != NULL );
+ debug("parsing address pair: '%s'\n", str);
+ addr->s_addr = 0;
+ mask->s_addr = 0;
+ ptr = str;
+ dsta = (u_char*)&addr->s_addr;
+ dstm = (u_char*)&mask->s_addr;
+ for (i=0; i<4; i++ ) {
+ if ( *ptr == '\0' )
+ break; /* case of format #3 */
+ if ( !isdigit(*ptr) )
+ return -1; /* format error: */
+ *dsta++ = atoi( ptr );
+ *dstm++ = 255; /* automatic mask for format #3 */
+ while ( isdigit(*ptr) ) /* skip digits */
+ ptr++;
+ if ( *ptr == '.' )
+ ptr++;
+ else
+ break;
+ }
+ /* At this point, *ptr points '/' or EOS ('\0') */
+ if ( *ptr == '\0' )
+ return 0; /* complete as format #3 */
+ if ( *ptr != '/' )
+ return -1; /* format error */
+ /* Now parse mask for format #1 or #2 */
+ ptr++;
+ mask->s_addr = 0; /* clear automatic mask */
+
+ if ( strchr( ptr, '.') ) {
+ /* case of format #1 */
+ dstm = (u_char*)&mask->s_addr;
+ for (i=0; i<4; i++) {
+ if ( !isdigit(*ptr) )
+ return -1; /* format error: */
+ *dstm++ = atoi(ptr);
+ while ( isdigit(*ptr) ) /* skip digits */
+ ptr++;
+ if ( *ptr == '.' )
+ ptr++;
+ else
+ break; /* from for loop */
+ }
+ /* complete as format #1 */
+ } else {
+ /* case of format #2 */
+ if ( !isdigit(*ptr) )
+ return -1; /* format error: */
+ n = atoi(ptr);
+ if ( n<0 || 32<n)
+ return -1; /* format error */
+ mask->s_addr = (n==0)? 0: htonl(((u_long)0xFFFFFFFF)<<(32-n));
+ /* complete as format #1 */
+ }
+ return 0;
+}
+
+void
+initialize_direct_addr (void)
+{
+ int negative;
+ int n_entries;
+ char *env = NULL, *beg, *next, *envkey = NULL;
+ struct in_addr addr, mask;
+
+ if ( relay_method == METHOD_SOCKS ){
+ if ( socks_version == 5 )
+ envkey = ENV_SOCKS5_DIRECT;
+ else
+ envkey = ENV_SOCKS4_DIRECT;
+ env = getparam(envkey);
+ if ( env == NULL )
+ env = getparam(ENV_SOCKS_DIRECT);
+ } else if ( relay_method == METHOD_HTTP ){
+ env = getparam(ENV_HTTP_DIRECT);
+ }
+
+ if ( env == NULL )
+ env = getparam(ENV_CONNECT_DIRECT);
+
+ if ( env == NULL )
+ return; /* no entry */
+ debug("making direct addr list from: '%s'\n", env);
+ env = strdup( env ); /* reallocate to modify */
+ beg = next = env;
+ n_entries = 0;
+ do {
+ if ( MAX_DIRECT_ADDR_LIST <= n_entries ) {
+ error("too many entries in %s", envkey);
+ break; /* from do loop */
+ }
+ next = strchr( beg, ',');
+ if ( next != NULL )
+ *next++ = '\0';
+ addr.s_addr = 0;
+ mask.s_addr = 0;
+ if (*beg == '!') {
+ negative = 1;
+ beg++;
+ } else
+ negative = 0;
+ if ( !parse_addr_pair( beg, &addr, &mask ) ) {
+ add_direct_addr( &addr, &mask, negative );
+ } else {
+ error("invalid addr format in %s: %s\n", envkey, beg);
+ }
+ if ( next != NULL )
+ beg = next;
+ } while ( next != NULL );
+
+ free( env );
+ return;
+}
+
+int
+cmp_addr (void *addr1, void *addr2, int addrlen)
+{
+ return memcmp( addr1, addr2, addrlen );
+}
+
+int
+is_direct_address (const struct sockaddr_in *addr)
+{
+ int i;
+ struct in_addr saddr, iaddr;
+
+ saddr = addr->sin_addr;
+
+ /* Note: assume IPV4 address !! */
+ for (i=0; i<n_direct_addr_list; i++ ) {
+ iaddr = saddr;
+ mask_addr( &iaddr, &direct_addr_list[i].mask,
+ sizeof(struct in_addr));
+ if (cmp_addr(&iaddr, &direct_addr_list[i].addr,
+ sizeof(struct in_addr)) == 0) {
+ if (direct_addr_list[i].negative) {
+ debug("negative match, addr to be SOCKSify: %s\n",
+ inet_ntoa(saddr));
+ return 0; /* not direct */
+ }
+ if (!direct_addr_list[i].negative) {
+ debug("positive match, addr to be direct: %s\n",
+ inet_ntoa(saddr));
+ return 1; /* direct*/
+ }
+ }
+ }
+ debug("not matched, addr to be SOCKSified: %s\n", inet_ntoa(saddr));
+ return 0; /* not direct */
+}
+
+
+/** TTY operation **/
+
+int intr_flag = 0;
+
+#ifndef _WIN32
+void
+intr_handler(int sig)
+{
+ intr_flag = 1;
+}
+
+void
+tty_change_echo(int fd, int enable)
+{
+ static struct termios ntio, otio; /* new/old termios */
+ static sigset_t nset, oset; /* new/old sigset */
+ static struct sigaction nsa, osa; /* new/old sigaction */
+ static int disabled = 0;
+
+ if ( disabled && enable ) {
+ /* enable echo */
+ tcsetattr(fd, TCSANOW, &otio);
+ disabled = 0;
+ /* resotore sigaction */
+ sigprocmask(SIG_SETMASK, &oset, NULL);
+ sigaction(SIGINT, &osa, NULL);
+ if ( intr_flag != 0 ) {
+ /* re-generate signal */
+ kill(getpid(), SIGINT);
+ sigemptyset(&nset);
+ sigsuspend(&nset);
+ intr_flag = 0;
+ }
+ } else if (!disabled && !enable) {
+ /* set SIGINTR handler and break syscall on singal */
+ sigemptyset(&nset);
+ sigaddset(&nset, SIGTSTP);
+ sigprocmask(SIG_BLOCK, &nset, &oset);
+ intr_flag = 0;
+ memset(&nsa, 0, sizeof(nsa));
+ nsa.sa_handler = intr_handler;
+ sigaction(SIGINT, &nsa, &osa);
+ /* disable echo */
+ if (tcgetattr(fd, &otio) == 0 && (otio.c_lflag & ECHO)) {
+ disabled = 1;
+ ntio = otio;
+ ntio.c_lflag &= ~(ECHO | ECHOE | ECHOK | ECHONL);
+ (void) tcsetattr(fd, TCSANOW, &ntio);
+ }
+ }
+
+ return;
+}
+
+#define TTY_NAME "/dev/tty"
+int
+tty_readpass( const char *prompt, char *buf, size_t size )
+{
+ int tty, ret = 0;
+
+ tty = open(TTY_NAME, O_RDWR);
+ if ( tty < 0 ) {
+ error("Unable to open %s\n", TTY_NAME);
+ return -1; /* can't open tty */
+ }
+ if ( size <= 0 )
+ return -1; /* no room */
+ write(tty, prompt, strlen(prompt));
+ buf[0] = '\0';
+ tty_change_echo(tty, 0); /* disable echo */
+ ret = read(tty,buf, size-1);
+ tty_change_echo(tty, 1); /* restore */
+ write(tty, "\n", 1); /* new line */
+ close(tty);
+ if ( strchr(buf,'\n') == NULL )
+ return -1;
+ if ( 0 < ret )
+ buf[ret] = '\0';
+ return ret;
+}
+
+#else /* _WIN32 */
+
+BOOL __stdcall
+w32_intr_handler(DWORD dwCtrlType)
+{
+ if ( dwCtrlType == CTRL_C_EVENT ) {
+ intr_flag = 1;
+ return TRUE;
+ } else {
+ return FALSE;
+ }
+}
+
+#define tty_readpass w32_tty_readpass
+int
+w32_tty_readpass( const char *prompt, char *buf, size_t size )
+{
+ HANDLE in = CreateFile("CONIN$", GENERIC_READ|GENERIC_WRITE,
+ 0, NULL, OPEN_EXISTING, 0, NULL);
+ HANDLE out = CreateFile("CONOUT$", GENERIC_WRITE,
+ 0, NULL, OPEN_EXISTING, 0, NULL);
+ DWORD mode;
+ DWORD ret, bytes;
+
+ if (in == INVALID_HANDLE_VALUE || out == INVALID_HANDLE_VALUE)
+ fatal("Cannot open console. (errno=%d)", GetLastError());
+
+ WriteFile(out, prompt, strlen(prompt), &bytes, 0);
+ SetConsoleCtrlHandler(w32_intr_handler, TRUE ); /* add handler */
+ GetConsoleMode(in, &mode);
+ SetConsoleMode(in, mode&~ENABLE_ECHO_INPUT); /* disable echo */
+ ret = ReadFile(in, buf, size, &bytes, 0);
+ SetConsoleMode(in, mode); /* enable echo */
+ SetConsoleCtrlHandler( w32_intr_handler, FALSE ); /* remove handler */
+ if ( intr_flag )
+ GenerateConsoleCtrlEvent(CTRL_C_EVENT, 0); /* re-signal */
+ WriteFile(out,"\n", 1, &bytes, 0);
+ CloseHandle(in);
+ CloseHandle(out);
+ return ret;
+}
+
+#endif /* _WIN32 */
+
+/*** User / Password ***/
+
+/* SOCKS5 and HTTP Proxy authentication may requires username and
+ password. We ll give it via environment variable or tty.
+ Username and password for authentication are decided by
+ following rules:
+
+ Username is taken from
+ 1) server location spec (i.e. user@host:port)
+ 2) environment variables (see tables.1)
+ 3) system account name currently logged in.
+
+ Table.1 Order of environment variables for username
+
+ | SOCKS v5 | SOCKS v4 | HTTP proxy |
+ --+-------------+-------------+-----------------+
+ 1 | SOCKS45_USER | SOCKS4_USER | HTTP_PROXY_USER |
+ --+-------------+-------------+ |
+ 2 | SOCKS_USER | |
+ --+---------------------------+-----------------+
+ 3 | CONNECT_USER |
+ --+---------------------------------------------+
+
+ Password is taken from
+ 1) by environment variables (see table.2)
+ 2) by entering from tty.
+
+ Table.2 Order of environment variables for password
+
+ | SOCKS v5 | HTTP proxy |
+ --+-----------------+---------------------+
+ 1 | SOCKS5_PASSWD | |
+ --+-----------------+ HTTP_PROXY_PASSWORD |
+ 2 | SOCKS5_PASSWORD | |
+ --+-----------------+---------------------+
+ 3 | CONNECT_PASSWORD |
+ --+---------------------------------------+
+
+ Note: SOCKS5_PASSWD which is added in rev. 1.79
+ to share value with NEC SOCKS implementation.
+ */
+
+char *
+determine_relay_user ()
+{
+ char *user = NULL;
+ /* get username from environment variable, or system. */
+ if (relay_method == METHOD_SOCKS) {
+ if (user == NULL && socks_version == 5)
+ user = getparam (ENV_SOCKS5_USER);
+ if (user == NULL && socks_version == 4)
+ user = getparam (ENV_SOCKS4_USER);
+ if (user == NULL)
+ user = getparam (ENV_SOCKS_USER);
+ } else if (relay_method == METHOD_HTTP) {
+ if (user == NULL)
+ user = getparam (ENV_HTTP_PROXY_USER);
+ }
+ if (user == NULL)
+ user = getparam (ENV_CONNECT_USER);
+ /* determine relay user by system call if not yet. */
+ if (user == NULL)
+ user = getusername();
+ return user;
+}
+
+char *
+determine_relay_password ()
+{
+ char *pass = NULL;
+ if (pass == NULL && relay_method == METHOD_HTTP)
+ pass = getparam(ENV_HTTP_PROXY_PASSWORD);
+ if (pass == NULL && relay_method == METHOD_SOCKS)
+ pass = getparam(ENV_SOCKS5_PASSWD);
+ if (pass == NULL && relay_method == METHOD_SOCKS)
+ pass = getparam(ENV_SOCKS5_PASSWORD);
+ if (pass == NULL)
+ pass = getparam(ENV_CONNECT_PASSWORD);
+ return pass;
+}
+
+
+/*** network operations ***/
+
+
+/* set_relay()
+ Determine relay informations:
+ method, host, port, and username.
+ 1st arg, METHOD should be METHOD_xxx.
+ 2nd arg, SPEC is hostname or hostname:port or user@hostame:port.
+ hostname is domain name or dot notation.
+ If port is omitted, use 80 for METHOD_HTTP method,
+ use 1080 for METHOD_SOCKS method.
+ Username is also able to given by 3rd. format.
+ 2nd argument SPEC can be NULL. if NULL, use environment variable.
+ */
+int
+set_relay( int method, char *spec )
+{
+ char *buf, *sep, *resolve;
+
+ relay_method = method;
+
+ read_parameter_file();
+ initialize_direct_addr();
+ if (n_direct_addr_list == 0) {
+ debug ("No direct address are specified.\n");
+ } else {
+ int i;
+ for ( i=0; i<n_direct_addr_list; i++ ) {
+ char *s1, *s2;
+ s1 = strdup(inet_ntoa(direct_addr_list[i].addr));
+ s2 = strdup(inet_ntoa(direct_addr_list[i].mask));
+ debug(" #%d: %c%s/%s\n", i,
+ (direct_addr_list[i].negative)? '!': ' ',
+ s1, s2);
+ free(s1);
+ free(s2);
+ }
+ }
+
+ switch ( method ) {
+ case METHOD_DIRECT:
+ return -1; /* nothing to do */
+
+ case METHOD_SOCKS:
+ if ( spec == NULL ) {
+ switch ( socks_version ) {
+ case 5:
+ spec = getparam(ENV_SOCKS5_SERVER);
+ break;
+ case 4:
+ spec = getparam(ENV_SOCKS4_SERVER);
+ break;
+ }
+ }
+ if ( spec == NULL )
+ spec = getparam(ENV_SOCKS_SERVER);
+
+ if ( spec == NULL )
+ fatal("Failed to determine SOCKS server.\n");
+ relay_port = 1080; /* set default first */
+
+ /* determine resolve method */
+ if ( socks_resolve == RESOLVE_UNKNOWN ) {
+ if ( ((socks_version == 5) &&
+ ((resolve = getparam(ENV_SOCKS5_RESOLVE)) != NULL)) ||
+ ((socks_version == 4) &&
+ ((resolve = getparam(ENV_SOCKS4_RESOLVE)) != NULL)) ||
+ ((resolve = getparam(ENV_SOCKS_RESOLVE)) != NULL) ) {
+ socks_resolve = lookup_resolve( resolve );
+ if ( socks_resolve == RESOLVE_UNKNOWN )
+ fatal("Invalid resolve method: %s\n", resolve);
+ } else {
+ /* default */
+ if ( socks_version == 5 )
+ socks_resolve = RESOLVE_REMOTE;
+ else
+ socks_resolve = RESOLVE_LOCAL;
+ }
+ }
+ break;
+
+ case METHOD_HTTP:
+ if ( spec == NULL )
+ spec = getparam(ENV_HTTP_PROXY);
+ if ( spec == NULL )
+ fatal("You must specify http proxy server\n");
+ relay_port = 80; /* set default first */
+ break;
+ case METHOD_TELNET:
+ if ( spec == NULL )
+ spec = getparam(ENV_TELNET_PROXY);
+ if ( spec == NULL )
+ fatal("You must specify telnet proxy server\n");
+ relay_port = 23; /* set default first */
+ }
+
+ if (expect( spec, HTTP_PROXY_PREFIX)) {
+ /* URL format like: "http://server:port/" */
+ /* extract server:port part */
+ buf = strdup( spec + strlen(HTTP_PROXY_PREFIX));
+ buf[strcspn(buf, "/")] = '\0';
+ } else {
+ /* assume spec is aready "server:port" format */
+ buf = strdup( spec );
+ }
+ spec = buf;
+
+ /* check username in spec */
+ sep = strchr( spec, '@' );
+ if ( sep != NULL ) {
+ *sep = '\0';
+ relay_user = strdup( spec );
+ spec = sep +1;
+ }
+ if (relay_user == NULL)
+ relay_user = determine_relay_user();
+
+ /* split out hostname and port number from spec */
+ sep = strchr(spec,':');
+ if ( sep == NULL ) {
+ /* hostname only, port is already set as default */
+ relay_host = strdup( spec );
+ } else {
+ /* hostname and port */
+ relay_port = atoi(sep+1);
+ *sep = '\0';
+ relay_host = strdup( spec );
+ }
+ free(buf);
+ return 0;
+}
+
+
+u_short
+resolve_port( const char *service )
+{
+ int port;
+ if ( service[strspn (service, digits)] == '\0' ) {
+ /* all digits, port number */
+ port = atoi(service);
+ } else {
+ /* treat as service name */
+ struct servent *ent;
+ ent = getservbyname( service, NULL );
+ if ( ent == NULL ) {
+ debug("Unknown service, '%s'\n", service);
+ port = 0;
+ } else {
+ port = ntohs(ent->s_port);
+ debug("service: %s => %d\n", service, port);
+ }
+ }
+ return (u_short)port;
+}
+
+void
+make_revstr(void)
+{
+ char *ptr;
+ size_t len;
+ ptr = strstr(rcs_revstr, ": ");
+ if (!ptr) {
+ revstr = strdup("unknown");
+ return;
+ }
+ ptr += 2;
+ len = strspn(ptr, dotdigits);
+ if (0 < len) {
+ revstr = xmalloc(len+1);
+ memcpy(revstr, ptr, len);
+ revstr[len] = '\0';
+ }
+}
+
+int
+getarg( int argc, char **argv )
+{
+ int err = 0;
+ char *ptr, *server = (char*)NULL;
+ int method = METHOD_DIRECT;
+
+ progname = *argv;
+ argc--, argv++;
+
+ /* check optinos */
+ while ( (0 < argc) && (**argv == '-') ) {
+ ptr = *argv + 1;
+ while ( *ptr ) {
+ switch ( *ptr ) {
+ case 's': /* use SOCKS */
+ method = METHOD_SOCKS;
+ break;
+
+ case 'n': /* no proxy */
+ method = METHOD_DIRECT;
+ break;
+
+ case 'h': /* use http-proxy */
+ method = METHOD_HTTP;
+ break;
+ case 't':
+ method = METHOD_TELNET;
+ break;
+
+ case 'S': /* specify SOCKS server */
+ if ( 1 < argc ) {
+ argv++, argc--;
+ method = METHOD_SOCKS;
+ server = *argv;
+ } else {
+ error("option '-%c' needs argument.\n", *ptr);
+ err++;
+ }
+ break;
+
+ case 'H': /* specify http-proxy server */
+ if ( 1 < argc ) {
+ argv++, argc--;
+ method = METHOD_HTTP;
+ server = *argv;
+ } else {
+ error("option '-%c' needs argument.\n", *ptr);
+ err++;
+ }
+ break;
+ case 'T': /* specify telnet proxy server */
+ if ( 1 < argc ) {
+ argv++, argc--;
+ method = METHOD_TELNET;
+ server = *argv;
+ } else {
+ error("option '-%c' needs argument.\n", *ptr);
+ err++;
+ }
+ break;
+
+ case 'c':
+ if (1 < argc) {
+ argv++, argc--;
+ telnet_command = *argv;
+ } else {
+ error("option '%c' needs argument.\n", *ptr);
+ err++;
+ }
+ break;
+
+ case 'P':
+ f_hold_session = 1;
+ /* without break */
+ case 'p': /* specify port to forward */
+ if ( 1 < argc ) {
+ argv++, argc--;
+ local_type = LOCAL_SOCKET;
+ local_port = resolve_port(*argv);
+ } else {
+ error("option '-%c' needs argument.\n", *ptr);
+ err++;
+ }
+ break;
+
+#ifndef _WIN32
+ case 'w':
+ if ( 1 < argc ) {
+ argv++, argc--;
+ connect_timeout = atoi(*argv);
+ } else {
+ error("option '-%c' needs argument.\n", *ptr);
+ err++;
+ }
+ break;
+#endif /* not _WIN32 */
+
+ case '4':
+ socks_version = 4;
+ break;
+
+ case '5':
+ socks_version = 5;
+ break;
+
+ case 'a':
+ if ( 1 < argc ) {
+ argv++, argc--;
+ socks5_auth = *argv;
+ } else {
+ error("option '-%c' needs argument.\n", *ptr);
+ err++;
+ }
+ break;
+
+ case 'R': /* specify resolve method */
+ if ( 1 < argc ) {
+ argv++, argc--;
+ socks_resolve = lookup_resolve( *argv );
+ } else {
+ error("option '-%c' needs argument.\n", *ptr);
+ err++;
+ }
+ break;
+
+ case 'V': /* print version */
+ fprintf(stderr, "%s\nVersion %s\n", progdesc, revstr);
+ exit(0);
+
+ case 'd': /* debug mode */
+ f_debug++;
+ break;
+
+ default:
+ error("unknown option '-%c'\n", *ptr);
+ err++;
+ }
+ ptr++;
+ }
+ argc--, argv++;
+ }
+
+ /* check error */
+ if ( 0 < err )
+ goto quit;
+
+ set_relay( method, server );
+
+ /* check destination HOST (MUST) */
+ if ( argc == 0 ) {
+ fprintf(stderr, "%s\nVersion %s\n", progdesc, revstr);
+ fprintf(stderr, usage, progname);
+ exit(0);
+ }
+ dest_host = argv[0];
+ /* decide port or service name from programname or argument */
+ if ( ((ptr=strrchr( progname, '/' )) != NULL) ||
+ ((ptr=strchr( progname, '\\')) != NULL) )
+ ptr++;
+ else
+ ptr = progname;
+ if ( dest_port == 0 ) {
+ /* accept only if -P is not specified. */
+ if ( 1 < argc ) {
+ /* get port number from argument (prior to progname) */
+ /* NOTE: This way is for cvs ext method. */
+ dest_port = resolve_port(argv[1]);
+ } else if ( strncmp( ptr, "connect-", 8) == 0 ) {
+ /* decide port number from program name */
+ char *str = strdup( ptr+8 );
+ str[strcspn( str, "." )] = '\0';
+ dest_port = resolve_port(str);
+ free(str);
+ }
+ }
+ /* check port number */
+ if ( dest_port <= 0 ) {
+ error( "You must specify the destination port correctly.\n");
+ err++;
+ goto quit;
+ }
+ if ( (relay_method != METHOD_DIRECT) && (relay_port <= 0) ) {
+ error("Invalid relay port: %d\n", dest_port);
+ err++;
+ goto quit;
+ }
+
+quit:
+ /* report for debugging */
+ debug("relay_method = %s (%d)\n",
+ method_names[relay_method], relay_method);
+ if ( relay_method != METHOD_DIRECT ) {
+ debug("relay_host=%s\n", relay_host);
+ debug("relay_port=%d\n", relay_port);
+ debug("relay_user=%s\n", relay_user);
+ }
+ if ( relay_method == METHOD_SOCKS ) {
+ debug("socks_version=%d\n", socks_version);
+ debug("socks_resolve=%s (%d)\n",
+ resolve_names[socks_resolve], socks_resolve);
+ }
+ debug("local_type=%s\n", local_type_names[local_type]);
+ if ( local_type == LOCAL_SOCKET ) {
+ debug("local_port=%d\n", local_port);
+ if (f_hold_session)
+ debug (" with holding remote session.\n");
+ }
+ debug("dest_host=%s\n", dest_host);
+ debug("dest_port=%d\n", dest_port);
+ if ( 0 < err ) {
+ fprintf(stderr, usage, progname);
+ exit(1);
+ }
+ return 0;
+}
+
+#ifndef _WIN32
+/* Time-out feature is not allowed for Win32 native compilers. */
+/* MSVC and Borland C cannot but Cygwin and UNIXes can. */
+
+/* timeout signal hander */
+void
+sig_timeout(void)
+{
+ debug( "timed out\n" );
+ signal( SIGALRM, SIG_IGN );
+ alarm( 0 );
+}
+
+/* set timeout param = seconds, 0 clears */
+void
+set_timeout(int timeout)
+{
+ /* This feature is allowed for UNIX or cygwin environments, currently */
+ if ( timeout == 0 ) {
+ debug( "clearing timeout\n" );
+ signal( SIGALRM, SIG_IGN );
+ alarm( 0 );
+ } else {
+ debug( "setting timeout: %d seconds\n", timeout );
+ signal(SIGALRM, (void *)sig_timeout);
+ alarm( timeout );
+ }
+}
+#endif
+
+#if !defined(_WIN32) && !defined(__CYGWIN32__)
+void
+switch_ns (struct sockaddr_in *ns)
+{
+ res_init();
+ memcpy (&_res.nsaddr_list[0], ns, sizeof(*ns));
+ _res.nscount = 1;
+ debug("Using nameserver at %s\n", inet_ntoa(ns->sin_addr));
+}
+#endif /* !_WIN32 && !__CYGWIN32__ */
+
+/* TODO: IPv6
+ TODO: fallback if askpass execution failed.
+ */
+
+int
+local_resolve (const char *host, struct sockaddr_in *addr)
+{
+ struct hostent *ent;
+ if ( strspn(host, dotdigits) == strlen(host) ) {
+ /* given by IPv4 address */
+ addr->sin_family = AF_INET;
+ addr->sin_addr.s_addr = inet_addr(host);
+ } else {
+ debug("resolving host by name: %s\n", host);
+ ent = gethostbyname (host);
+ if ( ent ) {
+ memcpy (&addr->sin_addr, ent->h_addr, ent->h_length);
+ addr->sin_family = ent->h_addrtype;
+ debug("resolved: %s (%s)\n",
+ host, inet_ntoa(addr->sin_addr));
+ } else {
+ debug("failed to resolve locally.\n");
+ return -1; /* failed */
+ }
+ }
+ return 0; /* good */
+}
+
+int
+open_connection( const char *host, u_short port )
+{
+ SOCKET s;
+ struct sockaddr_in saddr;
+
+ if ( relay_method == METHOD_DIRECT ) {
+ host = dest_host;
+ port = dest_port;
+ } else if ((local_resolve (dest_host, &saddr) >= 0)&&
+ (is_direct_address(&saddr))) {
+ debug("%s is connected directly\n", dest_host);
+ relay_method = METHOD_DIRECT;
+ host = dest_host;
+ port = dest_port;
+ } else {
+ host = relay_host;
+ port = relay_port;
+ }
+
+ if (local_resolve (host, &saddr) < 0) {
+ error("can't resolve hostname: %s\n", host);
+ return SOCKET_ERROR;
+ }
+ saddr.sin_port = htons(port);
+
+ debug("connecting to %s:%u\n", inet_ntoa(saddr.sin_addr), port);
+ s = socket( AF_INET, SOCK_STREAM, 0 );
+ if ( connect( s, (struct sockaddr *)&saddr, sizeof(saddr))
+ == SOCKET_ERROR) {
+ debug( "connect() failed.\n");
+ return SOCKET_ERROR;
+ }
+ return s;
+}
+
+void
+report_text( char *prefix, char *buf )
+{
+ static char work[1024];
+ char *tmp;
+
+ if ( !f_debug )
+ return;
+ if ( !f_report )
+ return; /* don't report */
+ debug("%s \"", prefix);
+ while ( *buf ) {
+ memset( work, 0, sizeof(work));
+ tmp = work;
+ while ( *buf && ((tmp-work) < (int)sizeof(work)-5) ) {
+ switch ( *buf ) {
+ case '\t': *tmp++ = '\\'; *tmp++ = 't'; break;
+ case '\r': *tmp++ = '\\'; *tmp++ = 'r'; break;
+ case '\n': *tmp++ = '\\'; *tmp++ = 'n'; break;
+ case '\\': *tmp++ = '\\'; *tmp++ = '\\'; break;
+ default:
+ if ( isprint(*buf) ) {
+ *tmp++ = *buf;
+ } else {
+ int consumed = tmp - work;
+ snprintf( tmp, sizeof(work)-consumed,
+ "\\x%02X", (unsigned char)*buf);
+ tmp += strlen(tmp);
+ }
+ }
+ buf++;
+ *tmp = '\0';
+ }
+ debug_("%s", work);
+ }
+
+ debug_("\"\n");
+}
+
+
+void
+report_bytes( char *prefix, char *buf, int len )
+{
+ if ( ! f_debug )
+ return;
+ debug( "%s", prefix );
+ while ( 0 < len ) {
+ fprintf( stderr, " %02x", *(unsigned char *)buf);
+ buf++;
+ len--;
+ }
+ fprintf(stderr, "\n");
+ return;
+}
+
+int
+atomic_out( SOCKET s, char *buf, int size )
+{
+ int ret, len;
+
+ assert( buf != NULL );
+ assert( 0<=size );
+ /* do atomic out */
+ ret = 0;
+ while ( 0 < size ) {
+ len = send( s, buf+ret, size, 0 );
+ if ( len == -1 )
+ fatal("atomic_out() failed to send(), %d\n", socket_errno());
+ ret += len;
+ size -= len;
+ }
+ if (!f_report) {
+ debug("atomic_out() [some bytes]\n");
+ debug(">>> xx xx xx xx ...\n");
+ } else {
+ debug("atomic_out() [%d bytes]\n", ret);
+ report_bytes(">>>", buf, ret);
+ }
+ return ret;
+}
+
+int
+atomic_in( SOCKET s, char *buf, int size )
+{
+ int ret, len;
+
+ assert( buf != NULL );
+ assert( 0<=size );
+
+ /* do atomic in */
+ ret = 0;
+ while ( 0 < size ) {
+ len = recv( s, buf+ret, size, 0 );
+ if ( len == -1 ) {
+ fatal("atomic_in() failed to recv(), %d\n", socket_errno());
+ } else if ( len == 0 ) {
+ fatal( "Connection closed by peer.\n");
+ }
+ ret += len;
+ size -= len;
+ }
+ if (!f_report) {
+ debug("atomic_in() [some bytes]\n");
+ debug("<<< xx xx xx xx ...\n");
+ } else {
+ debug("atomic_in() [%d bytes]\n", ret);
+ report_bytes("<<<", buf, ret);
+ }
+ return ret;
+}
+
+int
+line_input( SOCKET s, char *buf, int size )
+{
+ char *dst = buf;
+ if ( size == 0 )
+ return 0; /* no error */
+ size--;
+ while ( 0 < size ) {
+ switch ( recv( s, dst, 1, 0) ) { /* recv one-by-one */
+ case SOCKET_ERROR:
+ error("recv() error\n");
+ return -1; /* error */
+ case 0:
+ size = 0; /* end of stream */
+ break;
+ default:
+ /* continue reading until last 1 char is EOL? */
+ if ( *dst == '\n' ) {
+ /* finished */
+ size = 0;
+ } else {
+ /* more... */
+ size--;
+ }
+ dst++;
+ }
+ }
+ *dst = '\0';
+ report_text( "<<<", buf);
+ return 0;
+}
+
+/* cut_token()
+ Span token in given string STR until char in DELIM is appeared.
+ Then replace contiguous DELIMS with '\0' for string termination
+ and returns next pointer.
+ If no next token, return NULL.
+*/
+char *
+cut_token( char *str, char *delim)
+{
+ char *ptr = str + strcspn(str, delim);
+ char *end = ptr + strspn(ptr, delim);
+ if ( ptr == str )
+ return NULL;
+ while ( ptr < end )
+ *ptr++ = '\0';
+ return ptr;
+}
+
+const char *
+lookup(int num, LOOKUP_ITEM *items)
+{
+ int i = 0;
+ while (0 <= items[i].num) {
+ if (items[i].num == num)
+ return items[i].str;
+ i++;
+ }
+ return "(unknown)";
+}
+
+/* readpass()
+ password input routine
+ Use ssh-askpass (same mechanism to OpenSSH)
+*/
+char *
+readpass( const char* prompt, ...)
+{
+ static char buf[1000]; /* XXX, don't be fix length */
+ va_list args;
+ va_start(args, prompt);
+ vsnprintf(buf, sizeof(buf), prompt, args);
+ va_end(args);
+
+ if ( getparam(ENV_SSH_ASKPASS)
+#if !defined(_WIN32) && !defined(__CYGWIN32__)
+ && getenv("DISPLAY")
+#endif /* not _WIN32 && not __CYGWIN32__ */
+ ) {
+ /* use ssh-askpass to get password */
+ FILE *fp;
+ char *askpass = getparam(ENV_SSH_ASKPASS), *cmd;
+ int cmd_size = strlen(askpass) +1 +1 +strlen(buf) +1 +1;
+ cmd = xmalloc(cmd_size);
+ snprintf(cmd, cmd_size, "%s \"%s\"", askpass, buf);
+ fp = popen(cmd, "r");
+ free(cmd);
+ if ( fp == NULL )
+ return NULL; /* fail */
+ buf[0] = '\0';
+ if (fgets(buf, sizeof(buf), fp) == NULL)
+ return NULL; /* fail */
+ fclose(fp);
+ } else {
+ tty_readpass( buf, buf, sizeof(buf));
+ }
+ buf[strcspn(buf, "\r\n")] = '\0';
+ return buf;
+}
+
+static int
+socks5_do_auth_userpass( int s )
+{
+ unsigned char buf[1024], *ptr;
+ char *pass = NULL;
+ int len;
+
+ /* do User/Password authentication. */
+ /* This feature requires username and password from
+ command line argument or environment variable,
+ or terminal. */
+ if (relay_user == NULL)
+ fatal("cannot determine user name.\n");
+
+ /* get password from environment variable if exists. */
+ if ((pass=determine_relay_password()) == NULL &&
+ (pass=readpass("Enter SOCKS5 password for %s@%s: ",
+ relay_user, relay_host)) == NULL)
+ fatal("Cannot get password for user: %s\n", relay_user);
+
+ /* make authentication packet */
+ ptr = buf;
+ PUT_BYTE( ptr++, 1 ); /* subnegotiation ver.: 1 */
+ len = strlen( relay_user ); /* ULEN and UNAME */
+ PUT_BYTE( ptr++, len );
+ strcpy( ptr, relay_user );
+ ptr += len;
+ len = strlen( pass ); /* PLEN and PASSWD */
+ PUT_BYTE( ptr++, strlen(pass));
+ strcpy( ptr, pass );
+ ptr += len;
+ memset (pass, 0, strlen(pass)); /* erase password */
+
+ /* send it and get answer */
+ f_report = 0;
+ atomic_out( s, buf, ptr-buf );
+ f_report = 1;
+ atomic_in( s, buf, 2 );
+
+ /* check status */
+ if ( buf[1] == 0 )
+ return 0; /* success */
+ else
+ return -1; /* fail */
+}
+
+static const char *
+socks5_getauthname( int auth )
+{
+ switch ( auth ) {
+ case SOCKS5_AUTH_REJECT: return "REJECTED";
+ case SOCKS5_AUTH_NOAUTH: return "NO-AUTH";
+ case SOCKS5_AUTH_GSSAPI: return "GSSAPI";
+ case SOCKS5_AUTH_USERPASS: return "USERPASS";
+ case SOCKS5_AUTH_CHAP: return "CHAP";
+ case SOCKS5_AUTH_EAP: return "EAP";
+ case SOCKS5_AUTH_MAF: return "MAF";
+ default: return "(unknown)";
+ }
+}
+
+typedef struct {
+ char* name;
+ unsigned char auth;
+} AUTH_METHOD_ITEM;
+
+AUTH_METHOD_ITEM socks5_auth_table[] = {
+ { "none", SOCKS5_AUTH_NOAUTH },
+ { "gssapi", SOCKS5_AUTH_GSSAPI },
+ { "userpass", SOCKS5_AUTH_USERPASS },
+ { "chap", SOCKS5_AUTH_CHAP },
+ { NULL, -1 },
+};
+
+int
+socks5_auth_parse_1(char *start, char *end){
+ int i, len;
+ for ( ; *start; start++ )
+ if ( *start != ' ' && *start != '\t') break;
+ for ( end--; end >= start; end-- ) {
+ if ( *end != ' ' && *end != '\t'){
+ end++;
+ break;
+ }
+ }
+ len = end - start;
+ for ( i = 0; socks5_auth_table[i].name != NULL; i++ ){
+ if ( strncmp(start, socks5_auth_table[i].name, len) == 0) {
+ return socks5_auth_table[i].auth;
+ }
+ }
+ fatal("Unknown auth method: %s\n", start);
+ return -1;
+}
+
+int
+socks5_auth_parse(char *start, unsigned char *auth_list, int max_auth){
+ char *end;
+ int i = 0;
+ while ( i < max_auth ) {
+ end = strchr(start, ',');
+ if (*start && end) {
+ auth_list[i++] = socks5_auth_parse_1(start, end);
+ start = ++end;
+ } else {
+ break;
+ }
+ }
+ if ( *start && ( i < max_auth ) ){
+ for( end = start; *end; end++ );
+ auth_list[i++] = socks5_auth_parse_1(start, end);
+ } else {
+ fatal("Too much auth method.\n");
+ }
+ return i;
+}
+
+/* begin SOCKS5 relaying
+ And no authentication is supported.
+ */
+int
+begin_socks5_relay( SOCKET s )
+{
+ unsigned char buf[256], *ptr, *env = socks5_auth;
+ unsigned char n_auth = 0; unsigned char auth_list[10], auth_method;
+ int len, auth_result, i;
+
+ debug( "begin_socks_relay()\n");
+
+ /* request authentication */
+ ptr = buf;
+ PUT_BYTE( ptr++, 5); /* SOCKS version (5) */
+
+ if ( env == NULL )
+ env = getparam(ENV_SOCKS5_AUTH);
+ if ( env == NULL ) {
+ /* add no-auth authentication */
+ auth_list[n_auth++] = SOCKS5_AUTH_NOAUTH;
+ /* add user/pass authentication */
+ auth_list[n_auth++] = SOCKS5_AUTH_USERPASS;
+ } else {
+ n_auth = socks5_auth_parse(env, auth_list, 10);
+ }
+ PUT_BYTE( ptr++, n_auth); /* num auth */
+ for (i=0; i<n_auth; i++) {
+ debug("available auth method[%d] = %s (0x%02x)\n",
+ i, socks5_getauthname(auth_list[i]), auth_list[i]);
+ PUT_BYTE( ptr++, auth_list[i]); /* authentications */
+ }
+ atomic_out( s, buf, ptr-buf ); /* send requst */
+ atomic_in( s, buf, 2 ); /* recv response */
+ if ( (buf[0] != 5) || /* ver5 response */
+ (buf[1] == 0xFF) ) { /* check auth method */
+ error("No auth method accepted.\n");
+ return -1;
+ }
+ auth_method = buf[1];
+
+ debug("auth method: %s\n", socks5_getauthname(auth_method));
+
+ switch ( auth_method ) {
+ case SOCKS5_AUTH_REJECT:
+ error("No acceptable authentication method\n");
+ return -1; /* fail */
+
+ case SOCKS5_AUTH_NOAUTH:
+ /* nothing to do */
+ auth_result = 0;
+ break;
+
+ case SOCKS5_AUTH_USERPASS:
+ auth_result = socks5_do_auth_userpass(s);
+ break;
+
+ default:
+ error("Unsupported authentication method: %s\n",
+ socks5_getauthname( auth_method ));
+ return -1; /* fail */
+ }
+ if ( auth_result != 0 ) {
+ error("Authentication failed.\n");
+ return -1;
+ }
+ /* request to connect */
+ ptr = buf;
+ PUT_BYTE( ptr++, 5); /* SOCKS version (5) */
+ PUT_BYTE( ptr++, 1); /* CMD: CONNECT */
+ PUT_BYTE( ptr++, 0); /* FLG: 0 */
+ if ( dest_addr.sin_addr.s_addr == 0 ) {
+ /* resolved by SOCKS server */
+ PUT_BYTE( ptr++, 3); /* ATYP: DOMAINNAME */
+ len = strlen(dest_host);
+ PUT_BYTE( ptr++, len); /* DST.ADDR (len) */
+ memcpy( ptr, dest_host, len ); /* (hostname) */
+ ptr += len;
+ } else {
+ /* resolved localy */
+ PUT_BYTE( ptr++, 1 ); /* ATYP: IPv4 */
+ memcpy( ptr, &dest_addr.sin_addr.s_addr, sizeof(dest_addr.sin_addr));
+ ptr += sizeof(dest_addr.sin_addr);
+ }
+ PUT_BYTE( ptr++, dest_port>>8); /* DST.PORT */
+ PUT_BYTE( ptr++, dest_port&0xFF);
+ atomic_out( s, buf, ptr-buf); /* send request */
+ atomic_in( s, buf, 4 ); /* recv response */
+ if ( (buf[1] != SOCKS5_REP_SUCCEEDED) ) { /* check reply code */
+ error("Got error response from SOCKS server: %d (%s).\n",
+ buf[1], lookup(buf[1], socks5_rep_names));
+ return -1;
+ }
+ ptr = buf + 4;
+ switch ( buf[3] ) { /* case by ATYP */
+ case 1: /* IP v4 ADDR*/
+ atomic_in( s, ptr, 4+2 ); /* recv IPv4 addr and port */
+ break;
+ case 3: /* DOMAINNAME */
+ atomic_in( s, ptr, 1 ); /* recv name and port */
+ atomic_in( s, ptr+1, *(unsigned char*)ptr + 2);
+ break;
+ case 4: /* IP v6 ADDR */
+ atomic_in( s, ptr, 16+2 ); /* recv IPv6 addr and port */
+ break;
+ }
+
+ /* Conguraturation, connected via SOCKS5 server! */
+ return 0;
+}
+
+/* begin SOCKS protocol 4 relaying
+ And no authentication is supported.
+
+ There's SOCKS protocol version 4 and 4a. Protocol version
+ 4a has capability to resolve hostname by SOCKS server, so
+ we don't need resolving IP address of destination host on
+ local machine.
+
+ Environment variable SOCKS_RESOLVE directs how to resolve
+ IP addess. There's 3 keywords allowed; "local", "remote"
+ and "both" (case insensitive). Keyword "local" means taht
+ target host name is resolved by localhost resolver
+ (usualy with gethostbyname()), "remote" means by remote
+ SOCKS server, "both" means to try resolving by localhost
+ then remote.
+
+ SOCKS4 protocol and authentication of SOCKS5 protocol
+ requires user name on connect request.
+ User name is determined by following method.
+
+ 1. If server spec has user@hostname:port format then
+ user part is used for this SOCKS server.
+
+ 2. Get user name from environment variable LOGNAME, USER
+ (in this order).
+
+*/
+int
+begin_socks4_relay( SOCKET s )
+{
+ unsigned char buf[256], *ptr;
+
+ debug( "begin_socks_relay()\n");
+
+ /* make connect request packet
+ protocol v4:
+ VN:1, CD:1, PORT:2, ADDR:4, USER:n, NULL:1
+ protocol v4a:
+ VN:1, CD:1, PORT:2, DUMMY:4, USER:n, NULL:1, HOSTNAME:n, NULL:1
+ */
+ ptr = buf;
+ PUT_BYTE( ptr++, 4); /* protocol version (4) */
+ PUT_BYTE( ptr++, 1); /* CONNECT command */
+ PUT_BYTE( ptr++, dest_port>>8); /* destination Port */
+ PUT_BYTE( ptr++, dest_port&0xFF);
+ /* destination IP */
+ memcpy(ptr, &dest_addr.sin_addr, sizeof(dest_addr.sin_addr));
+ ptr += sizeof(dest_addr.sin_addr);
+ if ( dest_addr.sin_addr.s_addr == 0 )
+ *(ptr-1) = 1; /* fake, protocol 4a */
+ /* username */
+ if (relay_user == NULL)
+ fatal( "Cannot determine user name.\n");
+ strcpy( ptr, relay_user );
+ ptr += strlen( relay_user ) +1;
+ /* destination host name (for protocol 4a) */
+ if ( (socks_version == 4) && (dest_addr.sin_addr.s_addr == 0)) {
+ strcpy( ptr, dest_host );
+ ptr += strlen( dest_host ) +1;
+ }
+ /* send command and get response
+ response is: VN:1, CD:1, PORT:2, ADDR:4 */
+ atomic_out( s, buf, ptr-buf); /* send request */
+ atomic_in( s, buf, 8 ); /* recv response */
+ if ( (buf[1] != SOCKS4_REP_SUCCEEDED) ) { /* check reply code */
+ error("Got error response: %d: '%s'.\n",
+ buf[1], lookup(buf[1], socks4_rep_names));
+ return -1; /* failed */
+ }
+
+ /* Conguraturation, connected via SOCKS4 server! */
+ return 0;
+}
+
+int
+sendf(SOCKET s, const char *fmt,...)
+{
+ static char buf[10240]; /* xxx, enough? */
+
+ va_list args;
+ va_start( args, fmt );
+ vsnprintf( buf, sizeof(buf), fmt, args );
+ va_end( args );
+
+ report_text(">>>", buf);
+ if ( send(s, buf, strlen(buf), 0) == SOCKET_ERROR ) {
+ debug("failed to send http request. errno=%d\n", socket_errno());
+ return -1;
+ }
+ return 0;
+}
+
+const char *base64_table =
+"ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
+
+char *
+make_base64_string(const char *str)
+{
+ static char *buf;
+ unsigned char *src;
+ char *dst;
+ int bits, data, src_len, dst_len;
+ /* make base64 string */
+ src_len = strlen(str);
+ dst_len = (src_len+2)/3*4;
+ buf = xmalloc(dst_len+1);
+ bits = data = 0;
+ src = (unsigned char *)str;
+ dst = (unsigned char *)buf;
+ while ( dst_len-- ) {
+ if ( bits < 6 ) {
+ data = (data << 8) | *src;
+ bits += 8;
+ if ( *src != 0 )
+ src++;
+ }
+ *dst++ = base64_table[0x3F & (data >> (bits-6))];
+ bits -= 6;
+ }
+ *dst = '\0';
+ /* fix-up tail padding */
+ switch ( src_len%3 ) {
+ case 1:
+ *--dst = '=';
+ case 2:
+ *--dst = '=';
+ }
+ return buf;
+}
+
+
+int
+basic_auth (SOCKET s)
+{
+ char *userpass;
+ char *cred;
+ const char *user = relay_user;
+ char *pass = NULL;
+ int len, ret;
+
+ /* Get username/password for authentication */
+ if (user == NULL)
+ fatal("Cannot decide username for proxy authentication.");
+ if ((pass = determine_relay_password ()) == NULL &&
+ (pass = readpass("Enter proxy authentication password for %s@%s: ",
+ relay_user, relay_host)) == NULL)
+ fatal("Cannot decide password for proxy authentication.");
+
+ len = strlen(user)+strlen(pass)+1;
+ userpass = xmalloc(len+1);
+ snprintf(userpass, len+1, "%s:%s", user, pass);
+ memset (pass, 0, strlen(pass));
+ cred = make_base64_string(userpass);
+ memset (userpass, 0, len);
+
+ f_report = 0; /* don't report for security */
+ ret = sendf(s, "Proxy-Authorization: Basic %s\r\n", cred);
+ f_report = 1;
+ report_text(">>>", "Proxy-Authorization: Basic xxxxx\r\n");
+
+ memset(cred, 0, strlen(cred));
+ free(cred);
+
+ return ret;
+}
+
+/* begin relaying via HTTP proxy
+ Directs CONNECT method to proxy server to connect to
+ destination host (and port). It may not be allowed on your
+ proxy server.
+ */
+int
+begin_http_relay( SOCKET s )
+{
+ char buf[1024];
+ int result;
+ char *auth_what;
+
+ debug("begin_http_relay()\n");
+
+ if (sendf(s,"CONNECT %s:%d HTTP/1.0\r\n", dest_host, dest_port) < 0)
+ return START_ERROR;
+ if (proxy_auth_type == PROXY_AUTH_BASIC && basic_auth (s) < 0)
+ return START_ERROR;
+ if (sendf(s,"\r\n") < 0)
+ return START_ERROR;
+
+ /* get response */
+ if ( line_input(s, buf, sizeof(buf)) < 0 ) {
+ debug("failed to read http response.\n");
+ return START_ERROR;
+ }
+
+ /* check status */
+ if (!strchr(buf, ' ')) {
+ error ("Unexpected http response: '%s'.\n", buf);
+ return START_ERROR;
+ }
+ result = atoi(strchr(buf,' '));
+
+ switch ( result ) {
+ case 200:
+ /* Conguraturation, connected via http proxy server! */
+ debug("connected, start user session.\n");
+ break;
+ case 302: /* redirect */
+ do {
+ if (line_input(s, buf, sizeof(buf)))
+ break;
+ downcase(buf);
+ if (expect(buf, "Location: ")) {
+ relay_host = cut_token(buf, "//");
+ cut_token(buf, "/");
+ relay_port = atoi(cut_token(buf, ":"));
+ }
+ } while (strcmp(buf,"\r\n") != 0);
+ return START_RETRY;
+
+ /* We handle both 401 and 407 codes here: 401 is WWW-Authenticate, which
+ * not strictly the correct response, but some proxies do send this (e.g.
+ * Symantec's Raptor firewall) */
+ case 401: /* WWW-Auth required */
+ case 407: /* Proxy-Auth required */
+ /** NOTE: As easy implementation, we support only BASIC scheme
+ and ignore realm. */
+ /* If proxy_auth_type is PROXY_AUTH_BASIC and get
+ this result code, authentication was failed. */
+ if (proxy_auth_type != PROXY_AUTH_NONE) {
+ error("Authentication failed.\n");
+ return START_ERROR;
+ }
+ auth_what = (result == 401) ? "WWW-Authenticate:" : "Proxy-Authenticate:";
+ do {
+ if ( line_input(s, buf, sizeof(buf)) ) {
+ break;
+ }
+ downcase(buf);
+ if (expect(buf, auth_what)) {
+ /* parse type and realm */
+ char *scheme, *realm;
+ scheme = cut_token(buf, " ");
+ realm = cut_token(scheme, " ");
+ if ( scheme == NULL || realm == NULL ) {
+ debug("Invalid format of %s field.", auth_what);
+ return START_ERROR; /* fail */
+ }
+ /* check supported auth type */
+ if (expect(scheme, "basic")) {
+ proxy_auth_type = PROXY_AUTH_BASIC;
+ } else {
+ debug("Unsupported authentication type: %s", scheme);
+ }
+ }
+ } while (strcmp(buf,"\r\n") != 0);
+ if ( proxy_auth_type == PROXY_AUTH_NONE ) {
+ debug("Can't find %s in response header.", auth_what);
+ return START_ERROR;
+ } else {
+ return START_RETRY;
+ }
+
+ default:
+ /* Not allowed */
+ debug("http proxy is not allowed.\n");
+ return START_ERROR;
+ }
+ /* skip to end of response header */
+ do {
+ if ( line_input(s, buf, sizeof(buf) ) ) {
+ debug("Can't skip response headers\n");
+ return START_ERROR;
+ }
+ } while ( strcmp(buf,"\r\n") != 0 );
+
+ return START_OK;
+}
+
+/* begin relaying via TELNET proxy.
+ Sends string specified by telnet_command (-c option) with
+ replacing host name and port number to the socket. */
+int
+begin_telnet_relay( SOCKET s )
+{
+ char buf[1024];
+ char *cmd;
+ char *good_phrase = "connected to";
+ char *bad_phrase_list[] = {
+ " failed", " refused", " rejected", " closed"
+ };
+ char sep = ' ';
+ int i;
+
+ debug("begin_telnet_relay()\n");
+
+ /* report phrase */
+ debug("good phrase: '%s'\n", good_phrase);
+ debug("bad phrases");
+ sep = ':';
+ for (i=0; i< (sizeof(bad_phrase_list) / sizeof(char*)); i++) {
+ debug_("%c '%s'", sep, bad_phrase_list[i]);
+ sep = ',';
+ }
+ debug_("\n");
+
+ /* make request string with replacing %h by destination hostname
+ and %p by port number, etc. */
+ cmd = expand_host_and_port(telnet_command, dest_host, dest_port);
+
+ /* Sorry, we send request string now without waiting a prompt. */
+ if (sendf(s, "%s\r\n", cmd) < 0) {
+ free(cmd);
+ return START_ERROR;
+ }
+ free(cmd);
+
+ /* Process answer from proxy until good or bad phrase is detected. We
+ assume that the good phrase should be appeared only in the final
+ line of proxy responses. Bad keywods in the line causes operation
+ fail. First checks a good phrase, then checks bad phrases.
+ If no match, continue reading line from proxy. */
+ while (!line_input(s, buf, sizeof(buf)) && buf[0] != '\0') {
+ downcase(buf);
+ /* first, check good phrase */
+ if (strstr(buf, good_phrase)) {
+ debug("good phrase is detected: '%s'\n", good_phrase);
+ return START_OK;
+ }
+ /* then, check bad phrase */
+ for (i=0; i<(sizeof(bad_phrase_list)/sizeof(char*)); i++) {
+ if (strstr(buf, bad_phrase_list[i]) != NULL) {
+ debug("bad phrase is detected: '%s'\n", bad_phrase_list[i]);
+ return START_ERROR;
+ }
+ }
+ }
+ debug("error reading from telnet proxy\n");
+
+ return START_ERROR;
+}
+
+
+#ifdef _WIN32
+/* ddatalen()
+ Returns 1 if data is available, otherwise return 0
+ */
+int
+stdindatalen (void)
+{
+ DWORD len = 0;
+ struct stat st;
+ fstat( 0, &st );
+ if ( st.st_mode & _S_IFIFO ) {
+ /* in case of PIPE */
+ if ( !PeekNamedPipe( GetStdHandle(STD_INPUT_HANDLE),
+ NULL, 0, NULL, &len, NULL) ) {
+ if ( GetLastError() == ERROR_BROKEN_PIPE ) {
+ /* PIPE source is closed */
+ /* read() will detects EOF */
+ len = 1;
+ } else {
+ fatal("PeekNamedPipe() failed, errno=%d\n",
+ GetLastError());
+ }
+ }
+ } else if ( st.st_mode & _S_IFREG ) {
+ /* in case of regular file (redirected) */
+ len = 1; /* always data ready */
+ } else if ( _kbhit() ) {
+ /* in case of console */
+ len = 1;
+ }
+ return len;
+}
+#endif /* _WIN32 */
+
+/* relay byte from stdin to socket and fro socket to stdout.
+ returns reason of termination */
+int
+do_repeater( SOCKET local_in, SOCKET local_out, SOCKET remote )
+{
+ /** vars for local input data **/
+ char lbuf[1024]; /* local input buffer */
+ int lbuf_len; /* available data in lbuf */
+ int f_local; /* read local input more? */
+ /** vars for remote input data **/
+ char rbuf[1024]; /* remote input buffer */
+ int rbuf_len; /* available data in rbuf */
+ int f_remote; /* read remote input more? */
+ int close_reason = REASON_UNK; /* reason of end repeating */
+ /** other variables **/
+ int nfds, len;
+ fd_set ifds, ofds;
+ struct timeval *tmo;
+#ifdef _WIN32
+ struct timeval win32_tmo;
+#endif /* _WIN32 */
+
+ /* repeater between stdin/out and socket */
+ nfds = ((local_in<remote)? remote: local_in) +1;
+ f_local = 1; /* yes, read from local */
+ f_remote = 1; /* yes, read from remote */
+ lbuf_len = 0;
+ rbuf_len = 0;
+
+ while ( f_local || f_remote ) {
+ FD_ZERO(&ifds );
+ FD_ZERO(&ofds );
+ tmo = NULL;
+
+ /** prepare for reading local input **/
+ if ( f_local && (lbuf_len < (int)sizeof(lbuf)) ) {
+#ifdef _WIN32
+ if ( local_type != LOCAL_SOCKET ) {
+ /* select() on Winsock is not accept standard handle.
+ So use select() with short timeout and checking data
+ in stdin by another method. */
+ win32_tmo.tv_sec = 0;
+ win32_tmo.tv_usec = 10*1000; /* 10 ms */
+ tmo = &win32_tmo;
+ } else
+#endif /* !_WIN32 */
+ FD_SET( local_in, &ifds );
+ }
+
+ /** prepare for reading remote input **/
+ if ( f_remote && (rbuf_len < (int)sizeof(rbuf)) ) {
+ FD_SET( remote, &ifds );
+ }
+
+ /* FD_SET( local_out, ofds ); */
+ /* FD_SET( remote, ofds ); */
+
+ if ( select( nfds, &ifds, &ofds, (fd_set*)NULL, tmo ) == -1 ) {
+ /* some error */
+ error( "select() failed, %d\n", socket_errno());
+ return REASON_ERROR;
+ }
+#ifdef _WIN32
+ /* fake ifds if local is stdio handle because
+ select() of Winsock does not accept stdio
+ handle. */
+ if (f_local && (local_type!=LOCAL_SOCKET) && (0<stdindatalen()))
+ FD_SET(0,&ifds); /* data ready */
+#endif
+
+ /* remote => local */
+ if ( FD_ISSET(remote, &ifds) && (rbuf_len < (int)sizeof(rbuf)) ) {
+ len = recv( remote, rbuf + rbuf_len, sizeof(rbuf)-rbuf_len, 0);
+ if ( len == 0 ) {
+ debug("connection closed by peer\n");
+ close_reason = REASON_CLOSED_BY_REMOTE;
+ f_remote = 0; /* no more read from socket */
+ f_local = 0;
+ } else if ( len == -1 ) {
+ if (socket_errno() != ECONNRESET) {
+ /* error */
+ fatal("recv() faield, %d\n", socket_errno());
+ } else {
+ debug("ECONNRESET detected\n");
+ }
+ } else {
+ debug("recv %d bytes\n", len);
+ if ( 1 < f_debug ) /* more verbose */
+ report_bytes( "<<<", rbuf, rbuf_len);
+ rbuf_len += len;
+ }
+ }
+
+ /* local => remote */
+ if ( FD_ISSET(local_in, &ifds) && (lbuf_len < (int)sizeof(lbuf)) ) {
+ if (local_type == LOCAL_SOCKET)
+ len = recv(local_in, lbuf + lbuf_len,
+ sizeof(lbuf)-lbuf_len, 0);
+ else
+ len = read(local_in, lbuf + lbuf_len, sizeof(lbuf)-lbuf_len);
+ if ( len == 0 ) {
+ /* stdin is EOF */
+ debug("local input is EOF\n");
+ if (!f_hold_session)
+ shutdown(remote, 1); /* no-more writing */
+ f_local = 0;
+ close_reason = REASON_CLOSED_BY_LOCAL;
+ } else if ( len == -1 ) {
+ /* error on reading from stdin */
+ if (f_hold_session) {
+ debug ("failed to read from local\n");
+ f_local = 0;
+ close_reason = REASON_CLOSED_BY_LOCAL;
+ } else
+ fatal("recv() failed, errno = %d\n", errno);
+ } else {
+ /* repeat */
+ lbuf_len += len;
+ }
+ }
+
+ /* flush data in buffer to socket */
+ if ( 0 < lbuf_len ) {
+ len = send(remote, lbuf, lbuf_len, 0);
+ if ( 1 < f_debug ) /* more verbose */
+ report_bytes( ">>>", lbuf, lbuf_len);
+ if ( len == -1 ) {
+ fatal("send() failed, %d\n", socket_errno());
+ } else if ( 0 < len ) {
+ /* move data on to top of buffer */
+ debug("send %d bytes\n", len);
+ lbuf_len -= len;
+ if ( 0 < lbuf_len )
+ memcpy( lbuf, lbuf+len, lbuf_len );
+ assert( 0 <= lbuf_len );
+ }
+ }
+
+ /* flush data in buffer to local output */
+ if ( 0 < rbuf_len ) {
+ if (local_type == LOCAL_SOCKET)
+ len = send( local_out, rbuf, rbuf_len, 0);
+ else
+ len = write( local_out, rbuf, rbuf_len);
+ if ( len == -1 ) {
+ fatal("output (local) failed, errno=%d\n", errno);
+ }
+ rbuf_len -= len;
+ if ( len < rbuf_len )
+ memcpy( rbuf, rbuf+len, rbuf_len );
+ assert( 0 <= rbuf_len );
+ }
+ if (f_local == 0 && f_hold_session) {
+ debug ("closing local port without disconnecting from remote\n");
+ f_remote = 0;
+ shutdown (local_out, 2);
+ close (local_out);
+ break;
+ }
+ }
+
+ return close_reason;
+}
+
+int
+accept_connection (u_short port)
+{
+ static int sock = -1;
+ int connection;
+ struct sockaddr_in name;
+ struct sockaddr client;
+ int socklen;
+ fd_set ifds;
+ int nfds;
+ int sockopt;
+
+ /* Create the socket. */
+ debug("Creating source port to forward.\n");
+ sock = socket (PF_INET, SOCK_STREAM, 0);
+ if (sock < 0)
+ fatal("socket() failed, errno=%d\n", socket_errno());
+ sockopt = 1;
+ setsockopt (sock, SOL_SOCKET, SO_REUSEADDR,
+ (void*)&sockopt, sizeof(sockopt));
+
+ /* Give the socket a name. */
+ name.sin_family = AF_INET;
+ name.sin_port = htons (port);
+ name.sin_addr.s_addr = htonl (INADDR_ANY);
+ if (bind (sock, (struct sockaddr *) &name, sizeof (name)) < 0)
+ fatal ("bind() failed, errno=%d\n", socket_errno());
+
+ if (listen( sock, 1) < 0)
+ fatal ("listen() failed, errno=%d\n", socket_errno());
+
+ /* wait for new connection with watching EOF of stdin. */
+ debug ("waiting new connection at port %d (socket=%d)\n", port, sock);
+ nfds = sock + 1;
+ do {
+ int n;
+ struct timeval *ptmo = NULL;
+#ifdef _WIN32
+ struct timeval tmo;
+ tmo.tv_sec = 0;
+ tmo.tv_usec = 100*1000; /* On Windows, 100ms timeout */
+ ptmo = &tmo;
+#endif /* _WIN32 */
+ FD_ZERO (&ifds);
+ FD_SET ((SOCKET)sock, &ifds);
+#ifndef _WIN32
+ FD_SET (0, &ifds); /* watch stdin */
+#endif
+ n = select (nfds, &ifds, NULL, NULL, ptmo);
+ if (n == -1) {
+ fatal ("select() failed, %d\n", socket_errno());
+ exit (1);
+ }
+#ifdef _WIN32
+ if (0 < stdindatalen()) {
+ FD_SET (0, &ifds); /* fake */
+ n++;
+ }
+#endif
+ if (0 < n) {
+ if (FD_ISSET(0, &ifds) && (getchar() <= 0)) {
+ /* EOF */
+ debug ("Give-up waiting port because stdin is closed.");
+ exit(0);
+ }
+ if (FD_ISSET(sock, &ifds))
+ break; /* socket is stimulated */
+ }
+ } while (1);
+ socklen = sizeof(client);
+ connection = accept( sock, &client, &socklen);
+ if ( connection < 0 )
+ fatal ("accept() failed, errno=%d\n", socket_errno());
+ return connection;
+}
+
+
+
+/** Main of program **/
+int
+main( int argc, char **argv )
+{
+ int ret;
+ int remote; /* socket */
+ int local_in; /* Local input */
+ int local_out; /* Local output */
+ int reason;
+#ifdef _WIN32
+ WSADATA wsadata;
+ WSAStartup( 0x101, &wsadata);
+#endif /* _WIN32 */
+
+ /* initialization */
+ make_revstr();
+ getarg( argc, argv );
+ debug("Program is $Revision$\n");
+
+ /* Open local_in and local_out if forwarding a port */
+ if ( local_type == LOCAL_SOCKET ) {
+ /* Relay between local port and destination */
+ local_in = local_out = accept_connection( local_port );
+ } else {
+ /* Relay between stdin/stdout and desteination */
+ local_in = 0;
+ local_out = 1;
+#ifdef _WIN32
+ _setmode(local_in, O_BINARY);
+ _setmode(local_out, O_BINARY);
+#endif
+ }
+
+retry:
+#ifndef _WIN32
+ if (0 < connect_timeout)
+ set_timeout (connect_timeout);
+#endif /* not _WIN32 */
+
+ /* make connection */
+ if ( relay_method == METHOD_DIRECT ) {
+ remote = open_connection (dest_host, dest_port);
+ if ( remote == SOCKET_ERROR )
+ fatal( "Unable to connect to destination host, errno=%d\n",
+ socket_errno());
+ } else {
+ remote = open_connection (relay_host, relay_port);
+ if ( remote == SOCKET_ERROR )
+ fatal( "Unable to connect to relay host, errno=%d\n",
+ socket_errno());
+ }
+
+ /** resolve destination host (SOCKS) **/
+#if !defined(_WIN32) && !defined(__CYGWIN32__)
+ if (socks_ns.sin_addr.s_addr != 0)
+ switch_ns (&socks_ns);
+#endif /* not _WIN32 && not __CYGWIN32__ */
+ if (relay_method == METHOD_SOCKS &&
+ socks_resolve == RESOLVE_LOCAL &&
+ local_resolve (dest_host, &dest_addr) < 0) {
+ fatal("Unknown host: %s", dest_host);
+ }
+
+ /** relay negociation **/
+ switch ( relay_method ) {
+ case METHOD_SOCKS:
+ if ( ((socks_version == 5) && (begin_socks5_relay(remote) < 0)) ||
+ ((socks_version == 4) && (begin_socks4_relay(remote) < 0)) )
+ fatal( "failed to begin relaying via SOCKS.\n");
+ break;
+
+ case METHOD_HTTP:
+ ret = begin_http_relay(remote);
+ switch (ret) {
+ case START_ERROR:
+ close (remote);
+ fatal("failed to begin relaying via HTTP.\n");
+ case START_OK:
+ break;
+ case START_RETRY:
+ /* retry with authentication */
+ close (remote);
+ goto retry;
+ }
+ break;
+ case METHOD_TELNET:
+ if (begin_telnet_relay(remote) < 0)
+ fatal("failed to begin relaying via telnet.\n");
+ break;
+ }
+ debug("connected\n");
+
+#ifndef _WIN32
+ if (0 < connect_timeout)
+ set_timeout (0);
+#endif /* not _WIN32 */
+
+ /* main loop */
+ debug ("start relaying.\n");
+do_repeater:
+ reason = do_repeater(local_in, local_out, remote);
+ debug ("relaying done.\n");
+ if (local_type == LOCAL_SOCKET &&
+ reason == REASON_CLOSED_BY_LOCAL &&
+ f_hold_session) {
+ /* re-wait at local port without closing remote session */
+ debug ("re-waiting at local port %d\n", local_port);
+ local_in = local_out = accept_connection( local_port );
+ debug ("re-start relaying\n");
+ goto do_repeater;
+ }
+ closesocket(remote);
+ if ( local_type == LOCAL_SOCKET)
+ closesocket(local_in);
+#ifdef _WIN32
+ WSACleanup();
+#endif /* _WIN32 */
+ debug ("that's all, bye.\n");
+
+ return 0;
+}
+
+/* ------------------------------------------------------------
+ Local Variables:
+ compile-command: "cc connect.c -o connect"
+ tab-width: 8
+ fill-column: 74
+ comment-column: 48
+ End:
+ ------------------------------------------------------------ */
+
+/*** end of connect.c ***/
--- /dev/null
+<?xml version="1.0" encoding="us-ascii"?>\r
+<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN"\r
+ "http://www.w3.org/TR/xhtml1/DTD/strict.dtd">\r
+<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en">\r
+ <head>\r
+ <title>SSH Proxy Command -- connect.c</title>\r
+ <meta name="generator" content="emacs-wiki.el" />\r
+ <meta http-equiv="Content-Type"\r
+ content="us-ascii" />\r
+ <link rev="made" href="mailto:gotoh@taiyo.co.jp" />\r
+ <link rel="home" href="http://www.taiyo.co.jp/~gotoh/" />\r
+ <link rel="index" href="http://www.taiyo.co.jp/~gotoh/SiteIndex.html" />\r
+ <link rel="stylesheet" type="text/css" href="emacs-wiki.css" />\r
+ </head>\r
+ <body>\r
+ <h1>SSH Proxy Command -- connect.c</h1>\r
+ <!-- Page published by Emacs Wiki begins here -->\r
+<p>\r
+<strong>connect.c</strong> is the simple relaying command to make network\r
+connection via SOCKS and https proxy. It is mainly intended to\r
+be used as <strong>proxy command</strong> of OpenSSH. You can make SSH session\r
+beyond the firewall with this command,\r
+\r
+</p>\r
+\r
+<p>\r
+Features of <strong>connect.c</strong> are:\r
+\r
+</p>\r
+\r
+<ul>\r
+<li>Supports SOCKS (version 4/4a/5) and https CONNECT method.\r
+</li>\r
+<li>Supports NO-AUTH and USERPASS authentication of SOCKS\r
+</li>\r
+<li>Partially supports telnet proxy (experimental).\r
+</li>\r
+<li>You can input password from tty, ssh-askpass or\r
+ environment variable.\r
+</li>\r
+<li>Run on UNIX or Windows platform.\r
+</li>\r
+<li>You can compile with various C compiler (cc, gcc, Visual C, Borland C. etc.)\r
+</li>\r
+<li>Simple and general program independent from OpenSSH.\r
+</li>\r
+<li>You can also relay local socket stream instead of standard I/O.\r
+</li>\r
+</ul>\r
+\r
+<p>\r
+Download source code from:\r
+<a href="http://www.taiyo.co.jp/~gotoh/ssh/connect.c">http://www.taiyo.co.jp/~gotoh/ssh/connect.c</a>\r
+<br/>\r
+For windows user, pre-compiled binary is also available:\r
+<a href="http://www.taiyo.co.jp/~gotoh/ssh/connect.exe">http://www.taiyo.co.jp/~gotoh/ssh/connect.exe</a> (compiled with MSVC)\r
+\r
+</p>\r
+\r
+<h2>Contents</h2>\r
+<dl class="contents">\r
+<dt class="contents">\r
+<a href="#sec1">News</a>\r
+</dt>\r
+<dt class="contents">\r
+<a href="#sec2">What is 'proxy command'</a>\r
+</dt>\r
+<dt class="contents">\r
+<a href="#sec3">How to Use</a>\r
+</dt>\r
+<dd>\r
+<dl class="contents">\r
+<dt class="contents">\r
+<a href="#sec4">Get Source</a>\r
+</dt>\r
+<dt class="contents">\r
+<a href="#sec5">Compile and Install</a>\r
+</dt>\r
+<dt class="contents">\r
+<a href="#sec6">Modify your ~/.ssh/config</a>\r
+</dt>\r
+<dt class="contents">\r
+<a href="#sec7">Use SSH</a>\r
+</dt>\r
+<dt class="contents">\r
+<a href="#sec8">Have trouble?</a>\r
+</dt>\r
+</dl>\r
+</dd>\r
+<dt class="contents">\r
+<a href="#sec9">More Detail</a>\r
+</dt>\r
+<dt class="contents">\r
+<a href="#sec10">Specifying user name via environment variables</a>\r
+</dt>\r
+<dt class="contents">\r
+<a href="#sec11">Specifying password via environment variables</a>\r
+</dt>\r
+<dt class="contents">\r
+<a href="#sec12">Limitations</a>\r
+</dt>\r
+<dd>\r
+<dl class="contents">\r
+<dt class="contents">\r
+<a href="#sec13">SOCKS5 authentication</a>\r
+</dt>\r
+<dt class="contents">\r
+<a href="#sec14">HTTP authentication</a>\r
+</dt>\r
+<dt class="contents">\r
+<a href="#sec15">Switching proxy server</a>\r
+</dt>\r
+<dt class="contents">\r
+<a href="#sec16">Telnet Proxy</a>\r
+</dt>\r
+</dl>\r
+</dd>\r
+<dt class="contents">\r
+<a href="#sec17">Tips</a>\r
+</dt>\r
+<dd>\r
+<dl class="contents">\r
+<dt class="contents">\r
+<a href="#sec18">Proxying socket connection</a>\r
+</dt>\r
+<dt class="contents">\r
+<a href="#sec19">Use with ssh-askpass command</a>\r
+</dt>\r
+<dt class="contents">\r
+<a href="#sec20">Use for Network Stream of Emacs</a>\r
+</dt>\r
+<dt class="contents">\r
+<a href="#sec21">Remote resolver</a>\r
+</dt>\r
+<dt class="contents">\r
+<a href="#sec22">Hopping Connection via SSH</a>\r
+</dt>\r
+</dl>\r
+</dd>\r
+<dt class="contents">\r
+<a href="#sec23">Break The More Restricted Wall</a>\r
+</dt>\r
+<dt class="contents">\r
+<a href="#sec24">F.Y.I.</a>\r
+</dt>\r
+<dd>\r
+<dl class="contents">\r
+<dt class="contents">\r
+<a href="#sec25">Difference between SOCKS versions.</a>\r
+</dt>\r
+<dt class="contents">\r
+<a href="#sec26">Configuration to use HTTPS</a>\r
+</dt>\r
+<dt class="contents">\r
+<a href="#sec27">SOCKS5 Servers</a>\r
+</dt>\r
+<dt class="contents">\r
+<a href="#sec28">Specifications</a>\r
+</dt>\r
+<dt class="contents">\r
+<a href="#sec29">Related Links</a>\r
+</dt>\r
+<dt class="contents">\r
+<a href="#sec30">Similars</a>\r
+</dt>\r
+</dl>\r
+</dd>\r
+<dt class="contents">\r
+<a href="#sec31">hisotry</a>\r
+</dt>\r
+</dl>\r
+\r
+\r
+<h2><a name="sec1" id="sec1"></a>News</h2>\r
+<dl>\r
+<dt>2005-07-08</dt>\r
+<dd>\r
+Rev. 1.95. Buf fix for previous change. The bug causes the fail of\r
+ basic authentication. And also fixed bug of parameter file handling.\r
+ Thanks reporting, Johannes Schindelin <Johannes.Schindelin at gmx.de>.\r
+</dd>\r
+<dt>2005-07-07</dt>\r
+<dd>\r
+Rev. 1.94. Changed to use snprintf()/vsnprintf() for security issue\r
+ that gcc complained them on OpenBSD 3.7/x86. The features are not\r
+ changed.\r
+</dd>\r
+<dt>2005-03-04</dt>\r
+<dd>\r
+Updated compile option for Mac OS X.\r
+</dd>\r
+<dt>2005-02-21</dt>\r
+<dd>\r
+Rev.1.92. Removed assertions which has no mean and worse for windows\r
+ suggested by OZAWA Takahiro.\r
+</dd>\r
+<dt>2005-01-12</dt>\r
+<dd>\r
+Rev.1.90. Fixed not to cause seg-fault on accessing to non HTTP\r
+ port. This problem is reported by Jason Armstrong <ja at riverdrums.com>.\r
+</dd>\r
+<dt>2004-10-30</dt>\r
+<dd>\r
+Rev.1.89. Partial support for telnet proxy.\r
+ Thanks to Gregory Shimansky <gshimansky at mail dot ru>. \r
+ (Note: This is ad-hoc implementation, so it is not enough for\r
+ various type of telnet proxies.\r
+ And password interaction is not supported.)\r
+</dd>\r
+</dl>\r
+\r
+<h2><a name="sec2" id="sec2"></a>What is 'proxy command'</h2>\r
+\r
+<p>\r
+OpenSSH development team decides to stop supporting SOCKS and any\r
+other tunneling mechanism. It was aimed to separate complexity to\r
+support various mechanism of proxying from core code. And they\r
+recommends more flexible mechanism: <strong>ProxyCommand</strong> option\r
+instead.\r
+\r
+</p>\r
+\r
+<p>\r
+Proxy command mechanism is delegation of network stream\r
+communication. If <strong>ProxyCommand</strong> options is specified, SSH\r
+invoke specified external command and talk with standard I/O of thid\r
+command. Invoked command undertakes network communication with\r
+relaying to/from standard input/output including iniitial\r
+communication or negotiation for proxying. Thus, ssh can split out\r
+proxying code into external command.\r
+\r
+</p>\r
+\r
+<p>\r
+The <strong>connect.c</strong> program was made for this purpose.\r
+\r
+</p>\r
+\r
+<h2><a name="sec3" id="sec3"></a>How to Use</h2>\r
+\r
+<h3><a name="sec4" id="sec4"></a>Get Source</h3>\r
+\r
+<p>\r
+Download source code from <a href="http://www.taiyo.co.jp/~gotoh/ssh/connect.c">here</a>.\r
+<br/>\r
+If you are MS Windows user, you can get pre-compiled binary from\r
+<a href="http://www.taiyo.co.jp/~gotoh/ssh/connect.exe">here</a>.\r
+\r
+</p>\r
+\r
+<h3><a name="sec5" id="sec5"></a>Compile and Install</h3>\r
+\r
+<p>\r
+In most environment, you can compile <strong>connect.c</strong> simply.\r
+On UNIX environment, you can use cc or gcc.\r
+On Windows environment, you can use Microsoft Visual C, Borland C or Cygwin gcc.\r
+\r
+</p>\r
+\r
+<table border="2" cellpadding="5">\r
+<thead>\r
+<tr>\r
+<th>Compiler</th><th>command line to compile</th>\r
+</tr>\r
+</thead>\r
+<tbody>\r
+<tr>\r
+<td>UNIX cc</td><td>cc connect.c -o connect</td>\r
+</tr>\r
+<tr>\r
+<td>UNIX gcc</td><td>gcc connect.c -o connect</td>\r
+</tr>\r
+<tr>\r
+<td>Solaris</td><td>gcc connect.c -o connect -lnsl -lsocket -lresolv</td>\r
+</tr>\r
+<tr>\r
+<td>Microsoft Visual C/C++</td><td>cl connect.c wsock32.lib advapi32.lib</td>\r
+</tr>\r
+<tr>\r
+<td>Borland C</td><td>bcc32 connect.c wsock32.lib advapi32.lib</td>\r
+</tr>\r
+<tr>\r
+<td>Cygwin gcc</td><td>gcc connect.c -o connect</td>\r
+</tr>\r
+<tr>\r
+<td>Mac OS X</td><td>gcc connect.c -o connect -lresolv<br/>or<br/>gcc connect.c -o connect -DBIND_8_COMPAT=1</td>\r
+</tr>\r
+</tbody>\r
+</table>\r
+\r
+<p>\r
+To install <strong>connect</strong> command, simply copy compiled binary to directory\r
+in your PATH (ex. /usr/local/bin). Like this:\r
+\r
+</p>\r
+\r
+<pre class="example">\r
+$ cp connect /usr/local/bin\r
+</pre>\r
+\r
+<h3><a name="sec6" id="sec6"></a>Modify your ~/.ssh/config</h3>\r
+\r
+<p>\r
+Modify your <code>~/.ssh/config</code> file to use <strong>connect</strong> command as\r
+<strong>proxy command</strong>. For the case of SOCKS server is running on\r
+firewall host <code>socks.local.net</code> with port 1080, you can add\r
+<strong>ProxyCommand</strong> option in <code>~/.ssh/config</code>, like this:\r
+\r
+</p>\r
+\r
+<pre class="example">\r
+Host remote.outside.net\r
+ ProxyCommand connect -S socks.local.net %h %p\r
+</pre>\r
+\r
+<p>\r
+<code>%h</code> and <code>%p</code> will be replaced on invoking proxy command with\r
+target hostname and port specified to SSH command.\r
+\r
+</p>\r
+\r
+<p>\r
+If you hate writing many entries of remote hosts, following example\r
+may help you.\r
+\r
+</p>\r
+\r
+<pre class="example">\r
+## Inside of the firewall, use connect command with direct connection.\r
+Host *.local.net\r
+ ProxyCommand connect %h %p\r
+\r
+## Outside of the firewall, use connect command with SOCKS conenction.\r
+Host *\r
+ ProxyCommand connect -S socks.local.net %h %p\r
+</pre>\r
+\r
+<p>\r
+If you want to use http proxy, use <strong>-H</strong> option instead of <strong>-S</strong>\r
+option in examle above, like this:\r
+\r
+</p>\r
+\r
+<pre class="example">\r
+## Inside of the firewall, direct\r
+Host *.local.net\r
+ ProxyCommand connect %h %p\r
+\r
+## Outside of the firewall, with HTTP proxy\r
+Host *\r
+ ProxyCommand connect -H proxy.local.net:8080 %h %p\r
+</pre>\r
+\r
+<h3><a name="sec7" id="sec7"></a>Use SSH</h3>\r
+\r
+<p>\r
+After editing your <code>~/.ssh/config</code> file, you are ready to use ssh.\r
+You can execute ssh without any special options as if remote host is\r
+IP reachable host. Following is an example to execute <code>hostname</code>\r
+command on host <code>remote.outside.net</code>.\r
+\r
+</p>\r
+\r
+<pre class="example">\r
+$ ssh remote.outside.net hostname\r
+remote.outside.net\r
+$\r
+</pre>\r
+\r
+<h3><a name="sec8" id="sec8"></a>Have trouble?</h3>\r
+\r
+<p>\r
+If you have trouble, execute <strong>connect</strong> command from command line\r
+with <code>-d</code> option to see what is happened. Some debug message may\r
+appear and reports progress. This information may tell you what is\r
+wrong. In this example, error has occurred on authentication stage of\r
+SOCKS5 protocol.\r
+\r
+</p>\r
+\r
+<pre class="example">\r
+$ connect -d -S socks.local.net unknown.remote.outside.net 110\r
+DEBUG: relay_method = SOCKS (2)\r
+DEBUG: relay_host=socks.local.net\r
+DEBUG: relay_port=1080\r
+DEBUG: relay_user=gotoh\r
+DEBUG: socks_version=5\r
+DEBUG: socks_resolve=REMOTE (2)\r
+DEBUG: local_type=stdio\r
+DEBUG: dest_host=unknown.remote.outside.net\r
+DEBUG: dest_port=110\r
+DEBUG: Program is $Revision$\r
+DEBUG: connecting to xxx.xxx.xxx.xxx:1080\r
+DEBUG: begin_socks_relay()\r
+DEBUG: atomic_out() [4 bytes]\r
+DEBUG: >>> 05 02 00 02\r
+DEBUG: atomic_in() [2 bytes]\r
+DEBUG: <<< 05 02\r
+DEBUG: auth method: USERPASS\r
+DEBUG: atomic_out() [some bytes]\r
+DEBUG: >>> xx xx xx xx ...\r
+DEBUG: atomic_in() [2 bytes]\r
+DEBUG: <<< 01 01\r
+ERROR: Authentication faield.\r
+FATAL: failed to begin relaying via SOCKS.\r
+</pre>\r
+\r
+<h2><a name="sec9" id="sec9"></a>More Detail</h2>\r
+\r
+<p>\r
+Command line usage is here:\r
+\r
+</p>\r
+\r
+<pre class="example">\r
+usage: connect [-dnhst45] [-R resolve] [-p local-port] [-w sec]\r
+ [-H [user@]proxy-server[:port]]\r
+ [-S [user@]socks-server[:port]]\r
+ [-T socks-server:[port]]\r
+ [-c telnet-proxy-command]\r
+ host port\r
+</pre>\r
+\r
+<p>\r
+<strong><em>host</em></strong> and <strong><em>port</em></strong> is target hostname and port-number to connect.\r
+\r
+</p>\r
+\r
+<p>\r
+<strong>-H</strong> option specify hostname and port number of http proxy server to\r
+relay. If port is omitted, 80 is used. You can specify this value by\r
+environment variable <code>HTTP_PROXY</code> and give <strong>-h</strong> option to use it.\r
+\r
+</p>\r
+\r
+<p>\r
+<strong>-S</strong> option specify hostname and port number of SOCKS server to\r
+relay. Like <strong>-H</strong> option, port number can be omit and default is 1080. \r
+You can also specify this value pair by environment variable\r
+<code>SOCKS5_SERVER</code> and give <strong>-s</strong> option to use it.\r
+\r
+</p>\r
+\r
+<p>\r
+<strong>-T</strong> option specify hostname and port number of telnet proxy to\r
+relay. The port number can be omit and default is 23.\r
+You can also specify this value pair by environment variable\r
+<code>TELNET_PROXY</code> and give <strong>-t</strong> option to use it.\r
+\r
+</p>\r
+\r
+<p>\r
+<strong>-4</strong> and <strong>-5</strong> is for specifying SOCKS protocol version. It is\r
+valid only using with <strong>-s</strong> or <strong>-S</strong>. Default is <strong>-5</strong>\r
+(protocol version 5)\r
+\r
+</p>\r
+\r
+<p>\r
+<strong>-R</strong> is for specifying method to resolve hostname. 3 keywords\r
+(<code>local</code>, <code>remote</code>, <code>both</code>) or dot-notation IP address is\r
+allowed. Keyword <code>both</code> means; "Try local first, then\r
+remote". If dot-notation IP address is specified, use this host as\r
+nameserver (UNIX only). Default is <code>remote</code> for SOCKS5 or <code>local</code>\r
+for others. On SOCKS4 protocol, remote resolving method (<code>remote</code>\r
+and <code>both</code>) use protocol version 4a.\r
+\r
+</p>\r
+\r
+<p>\r
+The <strong>-p</strong> option specifys to wait a local TCP port and make relaying\r
+with it instead of standard input and output.\r
+\r
+</p>\r
+\r
+<p>\r
+The <strong>-w</strong> option specifys timeout seconds on making connection with\r
+target host.\r
+\r
+</p>\r
+\r
+<p>\r
+The <strong>-c</strong> option specifys request string against telnet\r
+proxy server. The special word '%h' and '%p' in this string are replaced\r
+as hostname and port number before sending. \r
+For telnet proxy by <a class="nonexistent" href="mailto:gotoh@taiyo.co.jp">DeleGate</a>, both "telnet %h %p" and "%h:%p"\r
+are acceptable.\r
+Default is "telnet %h %p".\r
+\r
+</p>\r
+\r
+<p>\r
+The <strong>-a</strong> option specifiys user intended authentication methods\r
+separated by comma. Currently <code>userpass</code> and <code>none</code> are\r
+supported. Default is <code>userpass</code>. You can also specifying this\r
+parameter by the environment variable <code>SOCKS5_AUTH</code>.\r
+\r
+</p>\r
+\r
+<p>\r
+The <strong>-d</strong> option is used for debug. If you fail to connect, use this\r
+and check request to and response from server.\r
+\r
+</p>\r
+\r
+<p>\r
+You can omit <strong><em>port</em></strong> argument when program name is special format\r
+containing port number itself. For example, \r
+\r
+</p>\r
+\r
+<pre class="example">\r
+$ ln -s connect connect-25\r
+$ ./connect-25 smtphost.outside.net\r
+220 smtphost.outside.net ESMTP Sendmail\r
+QUIT\r
+221 2.0.0 smtphost.remote.net closing connection\r
+$\r
+</pre>\r
+\r
+<p>\r
+This example means that the command name "<code>connect-25</code>" contains port number\r
+25 so you can omit 2nd argument (and used if specified explicitly).\r
+\r
+</p>\r
+\r
+<h2><a name="sec10" id="sec10"></a>Specifying user name via environment variables</h2>\r
+\r
+<p>\r
+There are 5 environemnt variables to specify\r
+user name without command line option. This mechanism is usefull\r
+for the user who using another user name different from system account.\r
+\r
+</p>\r
+\r
+<dl>\r
+<dt>SOCKS5_USER</dt>\r
+<dd>\r
+Used for SOCKS v5 access.\r
+</dd>\r
+<dt>SOCKS4_USER</dt>\r
+<dd>\r
+Used for SOCKS v4 access.\r
+</dd>\r
+<dt>SOCKS_USER</dt>\r
+<dd>\r
+Used for SOCKS v5 or v4 access and varaibles above are not defined.\r
+</dd>\r
+<dt>HTTP_PROXY_USER</dt>\r
+<dd>\r
+Used for HTTP proxy access.\r
+</dd>\r
+<dt>CONNECT_USER</dt>\r
+<dd>\r
+Used for all type of access if all above are not defined.\r
+</dd>\r
+</dl>\r
+\r
+<p>\r
+Following table describes how user name is determined.\r
+Left most number is order to check. If variable is not defined,\r
+check next variable, and so on.\r
+\r
+</p>\r
+\r
+<table border=1>\r
+<tr align=center><th></th><th>SOCKS v5</th><th>SOCKS v4</th><th>HTTP proxy</th></tr>\r
+<tr align=center><td>1</td><td>SOCKS5_USER</td><td>SOCKS4_USER</td><td rowspan=2>HTTP_PROXY_USER</td></tr>\r
+<tr align=center><td>2</td><td colspan=2>SOCKS_USER</td></tr>\r
+<tr align=center><td>3</td><td colspan=3>CONNECT_USER</td></tr>\r
+<tr align=center><td>4</td><td colspan=3><i>(query user name to system)</i></td></tr>\r
+</table>\r
+\r
+<h2><a name="sec11" id="sec11"></a>Specifying password via environment variables</h2>\r
+\r
+<p>\r
+There are 5 environemnt variables to specify\r
+password. If you use this feature, please note that it is\r
+not secure way.\r
+\r
+</p>\r
+\r
+<dl>\r
+<dt>SOCKS5_PASSWD</dt>\r
+<dd>\r
+Used for SOCKS v5 access. This variables is compatible\r
+ with NEC SOCKS implementation.\r
+</dd>\r
+<dt>SOCKS5_PASSWORD</dt>\r
+<dd>\r
+Used for SOCKS v5 access if SOCKS5_PASSWD is not defined.\r
+</dd>\r
+<dt>SOCKS_PASSWORD</dt>\r
+<dd>\r
+Used for SOCKS v5 (or v4) access all above is not defined.\r
+</dd>\r
+<dt>HTTP_PROXY_PASSWORD</dt>\r
+<dd>\r
+Used for HTTP proxy access.\r
+</dd>\r
+<dt>CONNECT_PASSWORD</dt>\r
+<dd>\r
+Used for all type of access if all above are not defined.\r
+</dd>\r
+</dl>\r
+\r
+<p>\r
+Following table describes how password is determined.\r
+Left most number is order to check. If variable is not defined,\r
+check next variable, and so on. Finally ask to user interactively\r
+using external program or tty input.\r
+\r
+</p>\r
+\r
+<table border=1>\r
+<tr align=center><th></th><th>SOCKS v5</th><th>HTTP proxy</th></tr>\r
+<tr align=center><td>1</td><td>SOCKS5_PASSWD</td><td rowspan=2>HTTP_PROXY_PASSWORD</td></tr>\r
+<tr align=center><td>2</td><td>SOCKS_PASSWORD</td></tr>\r
+<tr align=center><td>3</td><td colspan=2>CONNECT_PASSWORD</td></tr>\r
+<tr align=center><td>4</td><td colspan=2><i>(ask to user interactively)</i></td></tr>\r
+</table>\r
+\r
+<h2><a name="sec12" id="sec12"></a>Limitations</h2>\r
+\r
+<h3><a name="sec13" id="sec13"></a>SOCKS5 authentication</h3>\r
+\r
+<p>\r
+Only NO-AUTH and USER/PASSWORD authentications are supported.\r
+GSSAPI authentication (RFC 1961) and other draft authentications (CHAP,\r
+EAP, MAF, etc.) is not supported.\r
+\r
+</p>\r
+\r
+<h3><a name="sec14" id="sec14"></a>HTTP authentication</h3>\r
+\r
+<p>\r
+BASIC authentication is supported but DIGEST authentication is not.\r
+\r
+</p>\r
+\r
+<h3><a name="sec15" id="sec15"></a>Switching proxy server</h3>\r
+\r
+<p>\r
+There is no mechanism to switch proxy server regarding to PC environment.\r
+This limitation might be bad news for mobile user.\r
+Since I do not want to make this program complex, I do not want to\r
+support although this feature is already requested. Please advice me\r
+if there is good idea of detecting environment to swich and simple way\r
+to specify conditioned directive of servers.\r
+\r
+</p>\r
+\r
+<p>\r
+One tricky workaround exists. It is replacing ~/.ssh/config file\r
+by script on ppp up/down.\r
+\r
+</p>\r
+\r
+<p>\r
+There's another example of wrapper script (contributed by Darren Tucker).\r
+This script costs executing ifconfig and grep to detect\r
+current environment, but it works. (NOTE: you should modify addresses\r
+if you use it.)\r
+\r
+</p>\r
+\r
+<pre class="example">\r
+#!/bin/sh\r
+## ~/bin/myconnect --- Proxy server switching wrapper\r
+\r
+if ifconfig eth0 |grep "inet addr:192\.168\.1" >/dev/null; then\r
+ opts="-S 192.168.1.1:1080" \r
+elif ifconfig eth0 |grep "inet addr:10\." >/dev/null; then\r
+ opts="-H 10.1.1.1:80"\r
+else\r
+ opts="-s"\r
+fi\r
+exec /usr/local/bin/connect $opts $@\r
+</pre>\r
+\r
+<h3><a name="sec16" id="sec16"></a>Telnet Proxy</h3>\r
+\r
+<p>\r
+At first, note that the telnet proxy support is an partial feature.\r
+In this implementation, <strong>connect</strong> single requestinting and proxy\r
+returns some success/error detective in talked back lines including\r
+greeting, prompt and connected messages.\r
+\r
+</p>\r
+\r
+<p>\r
+The <strong>connect</strong> simply send request after connection to proxy is\r
+established before any response reading, then repeat reading response\r
+strings from proxy to decide remote connection request is succeeded or\r
+not by checking pre-defined phrase in each lines. There are\r
+pre-defined phrases which are good-phrase and bad-phrases. First\r
+good-phrase is checked and change state as relaying if exist.\r
+<strong>connect</strong> treat this line as final response from proxy before\r
+starting acutal communication with remote host. Or if good-phrase is\r
+not matched, bad-phrases will be checked. If one of bad-phrase\r
+matched, it cause connection error immediately.\r
+\r
+</p>\r
+\r
+<p>\r
+The pre-defined phrases are currently fixed string so you cannot\r
+change without modifying and compiling. The good-phrase is:\r
+"connected to". The bad-phrases are: " failed", " refused", "\r
+rejected", " closed".\r
+\r
+</p>\r
+\r
+<h2><a name="sec17" id="sec17"></a>Tips</h2>\r
+\r
+<h3><a name="sec18" id="sec18"></a>Proxying socket connection</h3>\r
+\r
+<p>\r
+In usual, <strong>connect.c</strong> relays network connection to/from standard\r
+input/output. By specifying <strong>-p</strong> option, however, <strong>connect.c</strong>\r
+relays local network stream instead of standard input/output.\r
+With this option, <strong>connect</strong> command waits connection\r
+from other program, then start relaying between both network stream.\r
+\r
+</p>\r
+\r
+<p>\r
+This feature may be useful for the program which is hard to SOCKSify.\r
+\r
+</p>\r
+\r
+<h3><a name="sec19" id="sec19"></a>Use with ssh-askpass command</h3>\r
+\r
+<p>\r
+<strong>connect.c</strong> ask you password when authentication is required. If\r
+you are using on tty/pty terminal, connect can input from terminal\r
+with prompt. But you can also use <code>ssh-askpass</code> program to input\r
+password. If you are graphical environment like X Window or MS\r
+Windows, and program does not have tty/pty, and environment variable\r
+SSH_ASKPASS is specified, then <strong>connect.c</strong> invoke command\r
+specified by environment variable <code>SSH_ASKPASS</code> to input password.\r
+<code>ssh-askpass</code> program might be installed if you are using OpenSSH on\r
+UNIX environment. On Windows environment, pre-compiled binary is\r
+available from\r
+<a href="http://www.taiyo.co.jp/~gotoh/ssh/ssh-askpass.exe">here</a>.\r
+\r
+</p>\r
+\r
+<p>\r
+This feature is limited on window system environment.\r
+\r
+</p>\r
+\r
+<p>\r
+And also useful on Emacs on MS Windows (NT Emacs or Meadow). It is\r
+hard to send passphrase to <strong>connect</strong> command (and also ssh)\r
+because external command is invoked on hidden terminal and do I/O with\r
+this terminal. Using ssh-askpass avoids this problem.\r
+\r
+</p>\r
+\r
+<h3><a name="sec20" id="sec20"></a>Use for Network Stream of Emacs</h3>\r
+\r
+<p>\r
+Although <strong>connect.c</strong> is made for OpenSSH, it is generic and\r
+independent from OpenSSH. So we can use this for other purpose. For\r
+example, you can use this command in Emacs to open network connection\r
+with remote host over the firewall via SOCKS or HTTP proxy without\r
+SOCKSifying Emacs itself.\r
+\r
+</p>\r
+\r
+<p>\r
+There is sample code: \r
+<a href="http://www.taiyo.co.jp/~gotoh/lisp/relay.el">http://www.taiyo.co.jp/~gotoh/lisp/relay.el</a>\r
+\r
+</p>\r
+\r
+<p>\r
+With this code, you can use <code>relay-open-network-stream</code> function\r
+instead of <code>open-network-stream</code> to make network connection. See top\r
+comments of source for more detail.\r
+\r
+</p>\r
+\r
+<h3><a name="sec21" id="sec21"></a>Remote resolver</h3>\r
+\r
+<p>\r
+If you are SOCKS4 user on UNIX environment, you might want specify\r
+nameserver to resolve remote hostname. You can do it specifying\r
+<strong>-R</strong> option followed by IP address of resolver.\r
+\r
+</p>\r
+\r
+<h3><a name="sec22" id="sec22"></a>Hopping Connection via SSH</h3>\r
+\r
+<p>\r
+Conbination of ssh and <strong>connect</strong> command have more interesting usage.\r
+Following command makes indirect connection to host2:port from your\r
+current host via host1.\r
+\r
+</p>\r
+\r
+<pre class="example">\r
+ssh host1 connect host2 port\r
+</pre>\r
+\r
+<p>\r
+This method is useful for the situations like:\r
+\r
+</p>\r
+\r
+<ul>\r
+<li>You are outside of organizasion now, but you want to access an\r
+ internal host barriered by firewall.\r
+</li>\r
+<li>You want to use some service which is allowed only from some\r
+ limited hosts.\r
+</li>\r
+</ul>\r
+\r
+<p>\r
+For example, I want to use local NetNews service in my office\r
+from home. I cannot make NNTP session directly because NNTP host is\r
+barriered by firewall. Fortunately, I have ssh account on internal\r
+host and allowed using SOCKS5 on firewall from outside. So I use\r
+following command to connect to NNTP service.\r
+\r
+</p>\r
+\r
+<pre class="example">\r
+$ ssh host1 connect news 119\r
+200 news.my-office.com InterNetNews NNRP server INN 2.3.2 ready (posting ok).\r
+quit\r
+205 .\r
+$\r
+</pre>\r
+\r
+<p>\r
+By combinating hopping connection and relay.el, I can read NetNews\r
+using <a href="http://www.gohome.org/wl/">Wanderlust</a> on Emacs at home.\r
+\r
+</p>\r
+\r
+<pre class="example">\r
+ |\r
+ External (internet) | Internal (office)\r
+ |\r
++------+ +----------+ +-------+ +-----------+\r
+| HOME | | firewall | | host1 | | NNTP host |\r
++------+ +----------+ +-------+ +-----------+\r
+ emacs <-------------- ssh ---------------> sshd <-- connect --> nntpd\r
+ <-- connect --> socksd <-- SOCKS -->\r
+</pre>\r
+\r
+<p>\r
+As an advanced example, you can use SSH hopping as fetchmail's plug-in\r
+program to access via secure tunnel. This method requires that\r
+<strong>connect</strong> program is insatalled on remote host. There's example\r
+of .fetchmailrc bellow. When fetchmail access to mail-server, you will\r
+login to remote host using SSH then execute <strong>connect</strong> program on\r
+remote host to relay conversation with pop server. Thus fetchmail can\r
+retrieve mails in secure.\r
+\r
+</p>\r
+\r
+<pre class="example">\r
+poll mail-server\r
+ protocol pop3\r
+ plugin "ssh %h connect localhost %p"\r
+ username "username"\r
+ password "password"\r
+</exmaple>\r
+\r
+* <a name="sec23" id="sec23"></a>Break The More Restricted Wall\r
+\r
+If firewall does not provide SOCKS nor HTTPS other than port 443, you\r
+cannot break the wall in usual way. But if you have you own host\r
+which is accessible from internet, you can make ssh connection to your\r
+own host by configuring sshd as waiting at port 443 instead of\r
+standard 22. By this, you can login to your own host via port 443.\r
+Once you have logged-in to extenal home machine, you can execute\r
+**connect** as second hop to make connection from your own host to\r
+final target host, like this:\r
+\r
+<example>\r
+$ cat ~/.ssh/config\r
+Host home\r
+ ProxyCommand connect -H firewall:8080 %h 443\r
+\r
+Host server\r
+ ProxyCommand ssh home connect %h %p\r
+...\r
+internal$ ssh home\r
+You are logged in to home!\r
+home# exit\r
+internal$ ssh server\r
+You are logged in to server!\r
+server# exit\r
+internal$\r
+</pre>\r
+\r
+<p>\r
+This way is similar to "Hopping connection via SSH" except configuring\r
+outer sshd as waiting at port 443 (https). This means that you have a\r
+capability to break the strongly restricted wall if you have own host\r
+out side of the wall.\r
+\r
+</p>\r
+\r
+<pre class="example">\r
+ |\r
+ Internal (office) | External (internet)\r
+ |\r
++--------+ +----------+ +------+ +--------+\r
+| office | | firewall | | home | | server |\r
++--------+ +----------+ +------+ +--------+\r
+ <------------------ ssh --------------------->sshd:443\r
+ <-- connect --> http-proxy <-- https:443 --> any\r
+ connect <-- tcp --> port\r
+</pre>\r
+\r
+<p>\r
+NOTE: If you wanna use this, you should give up hosting https service\r
+at port 443 on you external host 'home'.\r
+\r
+</p>\r
+\r
+<h2><a name="sec24" id="sec24"></a>F.Y.I.</h2>\r
+\r
+<h3><a name="sec25" id="sec25"></a>Difference between SOCKS versions.</h3>\r
+\r
+<p>\r
+SOCKS version 4 is first popular implementation which is documented\r
+<a href="http://www.socks.nec.com/protocol/socks4.protocol">here</a>. Since\r
+this protocol provide IP address based requesting, client program\r
+should resolve name of outer host by itself. Version 4a (documented\r
+<a href="http://www.socks.nec.com/protocol/socks4a.protocol">here</a>) is\r
+enhanced to allow request by hostname instead of IP address.\r
+\r
+</p>\r
+\r
+<p>\r
+SOCKS version 5 is re-designed protocol stands on experience of\r
+version 4 and 4a. There is no compativility with previous\r
+versions. Instead, there's some improvement: IPv6 support, request by\r
+hostname, UDP proxying, etc.\r
+\r
+</p>\r
+\r
+<h3><a name="sec26" id="sec26"></a>Configuration to use HTTPS</h3>\r
+\r
+<p>\r
+Many http proxy servers implementation supports https <code>CONNECT</code> method\r
+(SLL). You might add configuration to allow using https. For the\r
+example of <a href="http://www.delegate.org/delegate/">DeleGate</a> (\r
+DeleGate is a multi-purpose application level gateway, or a proxy\r
+server) , you should add <code>https</code> to <code>REMITTABLE</code> parameter to\r
+allow HTTP-Proxy like this:\r
+\r
+</p>\r
+\r
+<pre class="example">\r
+delegated -Pxxxx ...... REMITTABLE='+,https' ...\r
+</pre>\r
+\r
+<p>\r
+For the case of Squid, you should allow target ports via https by ACL,\r
+and so on.\r
+\r
+</p>\r
+\r
+<h3><a name="sec27" id="sec27"></a>SOCKS5 Servers</h3>\r
+\r
+<dl>\r
+<dt><a href="http://www.socks.nec.com/refsoftware.html">NEC SOCKS Reference Implementation</a></dt>\r
+<dd>\r
+Reference implementation of SOKCS server and library.\r
+</dd>\r
+<dt><a href="http://www.inet.no/dante/index.html">Dante</a></dt>\r
+<dd>\r
+Dante is free implementation of SOKCS server and library.\r
+ Many enhancements and modulalized.\r
+</dd>\r
+<dt><a href="http://www.delegate.org/delegate/">DeleGate</a></dt>\r
+<dd>\r
+DeleGate is multi function proxy service provider.\r
+ DeleGate 5.x.x or earlier can be SOCKS4 server,\r
+ and 6.x.x can be SOCKS5 and SOCKS4 server.\r
+ and 7.7.0 or later can be SOCKS5 and SOCKS4a server.\r
+</dd>\r
+</dl>\r
+\r
+<h3><a name="sec28" id="sec28"></a>Specifications</h3>\r
+\r
+<dl>\r
+<dt><a href="http://www.socks.nec.com/protocol/socks4.protocol">socks4.protocol.txt</a></dt>\r
+<dd>\r
+SOCKS: A protocol for TCP proxy across firewalls\r
+</dd>\r
+<dt><a href="http://www.socks.nec.com/protocol/socks4a.protocol">socks4a.protocol.txt</a></dt>\r
+<dd>\r
+SOCKS 4A: A Simple Extension to SOCKS 4 Protocol\r
+</dd>\r
+<dt><a href="http://www.socks.nec.com/rfc/rfc1928.txt">RFC 1928</a></dt>\r
+<dd>\r
+SOCKS Protocol Version 5\r
+</dd>\r
+<dt><a href="http://www.socks.nec.com/rfc/rfc1929.txt">RFC 1929</a></dt>\r
+<dd>\r
+Username/Password Authentication for SOCKS V5\r
+</dd>\r
+<dt><a href="http://www.ietf.org/rfc/rfc2616.txt">RFC 2616</a></dt>\r
+<dd>\r
+Hypertext Transfer Protocol -- HTTP/1.1\r
+</dd>\r
+<dt><a href="http://www.ietf.org/rfc/rfc2617.txt">RFC 2617</a></dt>\r
+<dd>\r
+HTTP Authentication: Basic and Digest Access Authentication\r
+</dd>\r
+</dl>\r
+\r
+<h3><a name="sec29" id="sec29"></a>Related Links</h3>\r
+\r
+<ul>\r
+<li><a href="http://www.openssh.org">OpenSSH Home</a>\r
+</li>\r
+<li><a href="http://www.ssh.com/">Proprietary SSH</a>\r
+</li>\r
+<li><a href="http://www.taiyo.co.jp/~gotoh/ssh/openssh-socks.html">Using OpenSSH through a SOCKS compatible PROXY on your LAN</a> (J. Grant)\r
+</li>\r
+</ul>\r
+\r
+<h3><a name="sec30" id="sec30"></a>Similars</h3>\r
+\r
+<ul>\r
+<li><a href="http://proxytunnel.sourceforge.net/">Proxy Tunnel</a> -- Proxying command using https CONNECT.\r
+</li>\r
+<li><a href="http://www.snurgle.org/~griffon/ssh-https-tunnel">stunnel</a> -- Proxy through an https tunnel (Perl script)\r
+</li>\r
+</ul>\r
+\r
+<h2><a name="sec31" id="sec31"></a>hisotry</h2>\r
+\r
+<dl>\r
+<dt>2004-07-21</dt>\r
+<dd>\r
+Rev.1.84. Fixed some typo.\r
+</dd>\r
+<dt>2004-05-18</dt>\r
+<dd>\r
+Rev.1.83. Fixed problem not work on Solaris.\r
+</dd>\r
+<dt>2004-04-27</dt>\r
+<dd>\r
+Rev.1.82. Bug fix of memory clear on http proxying.\r
+</dd>\r
+<dt>2004-04-22</dt>\r
+<dd>\r
+Rev. 1.81. Fixed memory violation and memory leak bug. New environment\r
+ variable SOCKS5_PASSWD for sharing value with NEC SOCKS implementation.\r
+ And document (this page) is updated.\r
+</dd>\r
+<dt>2004-03-30</dt>\r
+<dd>\r
+Rev. 1.76. Fixed to accept multiple 'Proxy-Authorization' response.\r
+</dd>\r
+<dt>2003-01-07</dt>\r
+<dd>\r
+Rev. 1.68. Fixed a trouble around timeout support.\r
+</dd>\r
+<dt>2002-11-21</dt>\r
+<dd>\r
+Rev. 1.64 supports reading parameters from file /etc/connectrc or\r
+ ~/.connectrc instead of specifying via environment variables. For\r
+ examle, you can use this feature to switch setting by replacing file\r
+ when network environment is changed. And added SOCKS_DIRECT,\r
+ SOCKS5_DIRECT, SOCKS4_DIRECT, HTTP_DIRECT, SOCKS5_AUTH, environment\r
+ parameters. (Thanks Masatoshi TSUCHIYA)\r
+</dd>\r
+<dt>2002-11-20</dt>\r
+<dd>\r
+Rev. 1.63 supports some old proxies which make response 401 with\r
+ WWW-Authenticate: header. And fixed to use username specified in\r
+ proxy host by -H option correctly. (contributed from Des Herriott, thanks)\r
+</dd>\r
+<dt>2002-10-14</dt>\r
+<dd>\r
+Rev. 1.61 with New option -w for specifying connection timeout.\r
+ Currently, it works on UNIX only. (contributed from Darren Tucker, thanks)\r
+</dd>\r
+<dt>2002-09-29</dt>\r
+<dd>\r
+Add sample script for switching proxy server\r
+ advised from Darren Tucker, thanks.\r
+</dd>\r
+<dt>2002-08-27</dt>\r
+<dd>\r
+connect.c is updataed to rev. 1.60.\r
+</dd>\r
+<dt>2002-04-08</dt>\r
+<dd>\r
+Updated <a href="http://www.taiyo.co.jp/~gotoh/ssh/openssh-socks.html">"Using OpenSSH through a SOCKS compatible PROXY on your LAN"</a> written by J. Grant. (version 0.8)\r
+</dd>\r
+<dt>2002-02-20</dt>\r
+<dd>\r
+Add link of new document "Using OpenSSH through a SOCKS compatible PROXY on your LAN"\r
+ written by J. Grant.\r
+</dd>\r
+<dt>2002-01-31</dt>\r
+<dd>\r
+Rev. 1.53 -- On Win32 and with MSVC, handle password\r
+ input from console correctly.\r
+</dd>\r
+<dt>2002-01-30</dt>\r
+<dd>\r
+Rev. 1.50 -- [Security Fix] Do not print secure info in debug mode.\r
+</dd>\r
+<dt>2002-01-09</dt>\r
+<dd>\r
+Web page was made.\r
+ connect.c is rev. 1.48.\r
+</dd>\r
+</dl>\r
+<br>\r
+\r
+ <!-- Page published by Emacs Wiki ends here -->\r
+ <div class="navfoot">\r
+ <hr/>\r
+ <table width="100%" border="0" summary="Footer navigation">\r
+ <tbody><tr>\r
+ <td width="50%" align="left">\r
+ <span class="footdate">Last Updated: 2005-07-18</span><br/>\r
+ </td>\r
+ <td width="50%" align="right">\r
+ This page is authored by <a href="mailto:gotoh@taiyo.co.jp">Shun-ichi GOTO</a>\r
+ using <a href="http://repose.cx/emacs/wiki">emacs-wiki.el</a><br/>\r
+ </td>\r
+ </tr></tbody>\r
+ </table>\r
+ </div>\r
+ </body>\r
+</html>\r
projects / packages / openssh.git / commitdiff