Net::SSH and port forwarding

[Jamis Buck]

Looks like the local->remote port forwarding will be pretty easy to
implement (I've already got a prototype that does the trick...messily).

At any rate, I'm looking at this and I'm realizing that because I'm
doing this all in Ruby, you could concievably have the port forwarding
do tricks based on additional information in the request. Here's a use
case to clarify my meaning:

Set up port forwarding on port X. When a connection is recieved, parse
the request. If the request matches format A, forward the request to
boxAortA. If the request matches format B, forward the request to
boxBortB. Etc. All of this happens transparently to the client that
connected to the local port.

Would this be useful for anyone? I'm probably going to write the Ruby
interface in such a way that you could do something like the above with
minimal effort, but I'm just curious if anyone would actually use such a
feature in practice.

--
Jamis Buck
(e-mail address removed)
http://www.jamisbuck.org/jamis

ruby -ropenssl
-e'k="01234567";p((c,c.padding,c.iv,c.key=OpenSSL::Cipher::BF.new,false,k,k*2)[0].decrypt.update("1A81803C452C324619D319F980D5B84DBB45FC0FE2BAA045".scan(/../).map{|n|n.to_i(16).chr}.join))'

 

[Dick Davies]

Set up port forwarding on port X. When a connection is recieved, parse
the request. If the request matches format A, forward the request to
boxAortA. If the request matches format B, forward the request to
boxBortB. Etc. All of this happens transparently to the client that
connected to the local port.

Would this be useful for anyone?

It would save you having to open multiple tunnels, at least in theory,
which would be very handy in a lot of circumstances.

If you could daemonize that you'd have an stunnel killer...

ruby -ropenssl
-e'k="01234567";p((c,c.padding,c.iv,c.key=OpenSSL::Cipher::BF.new,false,k,k*2)[0].decrypt.update("1A81803C452C324619D319F980D5B84DBB45FC0FE2BAA045".scan(/../).map{|n|n.to_i(16).chr}.join))'

 

[Jamis Buck]

It would save you having to open multiple tunnels, at least in theory,
which would be very handy in a lot of circumstances.

Actually, this is something you wouldn't be able to do even with
multiple tunnels, since you're still binding to a single port on the
localhost. You're just forwarding from that one port to multiple
different remote hosts, based on the format of the request.

As I said, it sounds cool, but I wonder how useful it would be in
practice. It should be in the next version of Net::SSH, regardless.

--
Jamis Buck
(e-mail address removed)
http://www.jamisbuck.org/jamis

"I use octal until I get to 8, and then I switch to decimal."