How to configure sshd to automatically do port forwarding

[Allen, Jack]

Hello:

        I have an Application needs to connect to other systems, login
run an Application and then transfer data to the other Application. This
has been working via a program I wrote years ago called ptsd (Pseudo
Terminal Server). Basically the ptsd program listens on a local port
(127.0.0.1 20000). The Application open a connection to it and then ptsd
prompts for some information and then makes a telnet connection to the
other system and then just becomes a pipe, but handling the telnet
protocol on one side of it.

        This need to be changed to use ssh for security reasons. I do
not want to write another program like ptsd to handle the ssh protocol.
I would rather be able to use ssh port forwarding feature to accomplish.
I have done a lot of Googling and found example of using the ssh command
line to do this, but nothing so far to make sshd or ssh do it
automatically. Also the command line example stated there was a
restriction that on one port forwarding per local port number could be
done at a time.

        So has anybody else had a need similar to this and was able to
make changes to ssh_config and/or sshd_config to accomplish.

        Just to make my request/question clear. The Application need to
be able to establish a simple TCP connection to a local TCP port
(127.0.0.1 20000). When this happen ssh/sshd would automatically make a
ssh connection to a predefine IP address TCP port 22. This way the
connection between Application system is secure and the most that has to
change in the Application is the send/expect values.

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Jack Allen