tunrdp.bat: SSH wrapper over old insecure RDP

Usage

Simply run this bat file from cmd or just by clicking on it, no administrative privelleges required.

It should work on Windows 10 and Windows 7.

Purpose

To wrap up and cover unsecure rdp session using ssh tunneling.

Use cases

• When ssh server installed on RDS server;
• When ssh server is in the same network as RDS server;
• When you need to access PC in the same network as the SSH server (RDP access should enabled on remote PC).

What this script is doing

1. Script will check if plink.exe already exist in C:\Users\%username%\ folder;
2. If it is not exist it will automatically attempt to download it from https://www.chiark.greenend.org.uk/~sgtatham/putty/latest.html using bitsadmin utility, and it won't download it if plink.exe exist in user's home directory;
3. Then it will initiate an SSH connection to remote SSH server in another CMD window to bring up the SSH tunnel and forward port from local user's PC to remote RDP server port (by default 3389);
4. Then it will start standard windows RDP utility mstsc.exe over localhost IP address and local port used in previous step;
5. When work is over and user logged out from RDP server, mstsc.exe utility exits, script then will attempt to kill plink.exe process opened in second shell to clear the processes;
6. And finally script will exit.

Author

Ilya Moiseev [email protected]

Credits

This piece of code uses third-party tool: plink.exe

It can be found here: https://www.chiark.greenend.org.uk/~sgtatham/putty/latest.html

License: https://www.chiark.greenend.org.uk/~sgtatham/putty/licence.html

Settings

Make sure to set all the values in correct manner in the script body, because I didn't implement any setting values checks :-)

For example:

IP address of SSH server to create a ssh tunnel using it:

set tunip=10.0.10.100

PORT of the SSH server to connect, default one is 22:

set tunport=22

IP address of destination RDP server:

set dstrdpip=10.0.10.111

PORT of the RDP server, default one is 3389:

set dstrdpport=3389

PORT on localhost (127.0.0.1) interface to connect on using RDP utility (mstsc.exe), you can leave 13777 as the default one:

set localtunport=13777

USER with access to SSH server, this needs to be configured on SSH server side separately, general recommendation is: create non-admin user with /usr/sbin/nologin as user's shell:

set tunsshuser=tunnelrdpuser

PASSWORD for the SSH server user, yes, in insecure manner. Do not generate password with special symbols, there will be an issue with batch handling it:

set tunsshuserpwd=M3GaSEcR3tPAsSwOrD

SSH server fingerprint, with this setting, plink.exe won't ask you to confirm and won't put this fingerprint into the registry. You can find it by issuing: plink.exe -v -batch $HOSTNAME -P $PORT_NUMBER The string after "Host key finger print is:" is our fingerprint to put here:

set sshtunhostkey=18:c2:4d:3f:79:c2:c3:4a:76:14:44:83:8f:47:ae:ad