Setting up an SSH Tunnel between CPRS & VistA

Begin by installing putty onto your Windows client machine. Download from here: http://www.chiark.greenend.org.uk/~sgtatham/putty/download.html You need the program Plink (a command-line interface to the PuTTY back ends).

We then can use plink.exe to construct an encrypted path between the local machine (127.0.0.1) and a remote location (here it is 192.168.5.102). The remote machine at address 192.168.5.102 happens to be listening at port 9260. Note that the local port chosen in this example is independently set to 9210. We could have used 9260, or any port that has no conflict.

And on the remote machine we have added a user named "plinkuser" with password "plinkpw" solely to establish the tunnel. Here is the complete command to implement our tunnel:

"C:\Program Files\PuTTY\plink.exe" -N -ssh -l plinkuser -pw plinkpw -L 9210:127.0.0.1:9260 192.168.5.102

translation (from plink documentation):

   -N    Do not start a shell
   -ssh  encrypted link
   -l    user name on the remote system, here we have set up "remoteaccess"
   -pw   password for the remote user, in this example it is "remotepw"
   -L    local_port:address:remote_port remote_address

Now, if the Windows shortcut for CPRS will use the local port and address, a secure connection will be made to the remote port and address at the other end. So you replace

... -s 192.168.5.102 -p 9260 ...

with

... -s 127.0.0.1 -p 9210 ...

and the CPRS client will connect exactly as before but now over the secure SSH tunnel.

under construction, input welcome. --JL.Z 07:00, 21 Aug 2009 (PDT)