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Backend PLINK (SSH) Option


New as of Mar16, 2017: Update to putty-0.68!

uCon supports a "plink" backend. Plink is the command line portion of the open-source PuTTY client (see copyright below). For details on PuTTY, refer to http://www/chiark.greenend.org.uk/~sgtatham/putty. In the nutshell, this gives uCon the ability to connect to remote servers via SSH and RLOGIN, with SSH being the primary motivation for this capability.

The plink connection dialog box is started through the menu item Config->Backends->Plink and allows the user to enter the arguments that would normally be passed to plink at a command line interface (see below for new-as-of-mar-2015 option)...

To initiate the SSH client, type in the username followed by an '@' sign followed by the name of the machine you wish to connect to (refer to the example in the dialog box), then click OK.  New as of Aug 2015: To override the default SSH port, you can append a ":portnum" to the end of the string or prefix the line with "-P portnum"...

username@machine.domain.com:PORT

or 

-P PORT username@machine.domain.com

Theoretically, any set of command line arguments that could be passed to plink.exe at a console window should be able to be placed in this dialog box as an argument to plink. That being said, below is the help output of "plink --help" (version 0.68) when run at the command line...

Plink: command-line connection utility
Release 0.68
Usage: plink [options] [user@]host [command]
       ("host" can also be a PuTTY saved session name)
Options:
  -V        print version information and exit
  -pgpfp    print PGP key fingerprints and exit
  -v        show verbose messages
  -load sessname  Load settings from saved session
  -ssh -telnet -rlogin -raw -serial
            force use of a particular protocol
  -P port   connect to specified port
  -l user   connect with specified username
  -batch    disable all interactive prompts
  -proxycmd command
            use 'command' as local proxy
  -sercfg configuration-string (e.g. 19200,8,n,1,X)
            Specify the serial configuration (serial only)
The following options only apply to SSH connections:
  -pw passw login with specified password
  -D [listen-IP:]listen-port
            Dynamic SOCKS-based port forwarding
  -L [listen-IP:]listen-port:host:port
            Forward local port to remote address
  -R [listen-IP:]listen-port:host:port
            Forward remote port to local address
  -X -x     enable / disable X11 forwarding
  -A -a     enable / disable agent forwarding
  -t -T     enable / disable pty allocation
  -1 -2     force use of particular protocol version
  -4 -6     force use of IPv4 or IPv6
  -C        enable compression
  -i key    private key file for user authentication
  -noagent  disable use of Pageant
  -agent    enable use of Pageant
  -hostkey aa:bb:cc:...
            manually specify a host key (may be repeated)
  -m file   read remote command(s) from file
  -s        remote command is an SSH subsystem (SSH-2 only)
  -N        don't start a shell/command (SSH-2 only)
  -nc host:port
            open tunnel in place of session (SSH-2 only)
  -sshlog file
  -sshrawlog file
            log protocol details to a file
  -shareexists
            test whether a connection-sharing upstream exists

Note that as of this writing, the only thing that has been tested with uCon is the default SSH client running through plink release 0.68; however, you're welcome to experiment and let me know what works and doesn't work!

NOTE:
The plink exectuable is verified with an md5sum.  To use a newer/different putty, you'll need to override the md5sum using the PLINKVERIFY shell variable.  To do this, set the variable to IGNORE (to bypass verification) or the md5sum calculated on the plink.exe you install.

PuTTY LICENCE file:

PuTTY is copyright 1997-2017 Simon Tatham.

Portions copyright Robert de Bath, Joris van Rantwijk, Delian Delchev, Andreas Schultz, Jeroen Massar, Wez Furlong, Nicolas Barry,Justin Bradford, Ben Harris, Malcolm Smith, Ahmad Khalifa, Markus Kuhn, Colin Watson, Christopher Staite, and CORE SDI S.A.

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.



New, unusual feature (as of Mar 2015)

There's a new totally disjoint option to this dialog box...
If you set the "Plink arguments" textbox to "CMD" (don't include the quotes), then the console window of uCon will open up a CMD shell. For reasons beyond the scope of this text, I had a use for this at one point.  
I left it in uCon only to provide an alternative remote access mechanism to the PC through telnet...
If you set up the telnet server to be active, then you can telnet into uCon from another machine and access a CMD shell.
Obviously there are other more modern ways to do the same with more capability (i.e. VNC), but its here to use if you can find a reason.
Note that this applies to the startup dialog box of uCon as well.