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SSLH(1) 	       User Contributed Perl Documentation		 SSLH(1)

NAME
     sslh - Switch incoming connection between SSH and SSL/HTTPS servers

SYNOPSIS
     sslh [ -v ] [ -p [host:]port ] [ -t timeout ]
	  [ --ssh [host:]port ] [ --ssl [host:]port ]

DESCRIPTION
     sslh is a simple script that lets you switch an incoming connection on a
     single port between distinct SSH and SSL/HTTPS servers.

     sslh listens for connections on a port and is able to redirect them either
     to an HTTPS web server or a SSH server.

     This lets one setup both a HTTPS web server and a SSH server and access
     them through the same host+port.

OPTIONS
     The program follows the usual GNU command line syntax, with long options
     starting with two dashes.

     -p, --port [host:]port
	 The port the proxy will listen to.  If no port is given, 443 is used by
	 default.  If no host is given, "localhost" is used by default.

     -s, --ssh [host:]port
	 The SSH server which the SSH connections must be forwarded to.  If
	 omitted, the default is localhost:22.

     -l, --ssl, --https [host:]port
	 The HTTPS server which the HTTPS connections must be forwarded to.  If
	 omitted, the default is localhost:443.

     -t, --timeout delay
	 Timeout in seconds before a silent incoming connection is considered as
	 a SSH connection. The number can be fractional.

	 The default is 2seconds.

     -v, --verbose
	 Verbose output.  This option can be used several times for more verbose
	 output.

EXAMPLE OF USE
     Is this tool actually useful? Yes.

     For example one can use it to access both a SSH server and a secure web
     server via a corporate proxy that only accepts to relay connections to port
     443. Creating a tunnel that passes SSH connection through a CONNECT-enabled
     web proxy is easy with connect-tunnel (also included in the "Net::Proxy"
     distribution).

     The proxy will let both SSH and HTTPS connections out (since they all point
     to port 443), and the home server will connect those incoming connections
     to the appropriate server. This only requires to run the HTTPS server on a
     non standard port (not 443).

TECHNICAL NOTE
     How can this proxy find out what kind of protocol is using a TCP connection
     to port 443, without being connected (yet) to the server?	We actually rely
     on a slight difference between the SSL and SSH protocols (found thanks to
     ethereal):

     SSH Once the TCP connection is established, the server speaks first, pre-
	 senting itself by saying something like:

	     SSH-2.0-OpenSSH_3.6.1p2 Debian 1:3.6.1p2-1

     SSL With SSL, it's always the client that speaks first.

     This means that sslh can be used with any pair of protocols/services that
     share this property (the client speaks first for one and the server speaks
     first for the other).

AUTHORS
     Original idea and C version
	 FrA(C)dA(C)ric PlA(C) "<frederic.ple+sslh@gmail.com>".

     Perl versions
	 Philippe 'BooK' Bruhat "<book@cpan.org>".

SCRIPT HISTORY
     Version 0.01 of the script was a quick hack designed in 2003 as a proof of
     concept.

     Version 0.02 (and higher) are based on "Net::Proxy", and included with the
     "Net::Proxy" distribution. Version 0.02 didn't work, though.

     Version 0.03 correctly initialised the "in" connector.

     Version 0.04 lets the proxy listen on any address (instead of "localhost",
     which is still the default). Thanks to Dieter Voegtli for spotting this.

SEE ALSO
     Net::Proxy, Net::Proxy::Connector::dual.

COPYRIGHT
     Copyright 2003-2008, Philippe Bruhat. All rights reserved.

LICENSE
     This module is free software; you can redistribute it or modify it under
     the same terms as Perl itself.

perl v5.42.3			   2014-11-02				 SSLH(1)
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