Setting Automatic Remote Login

TracNav

It is possible to use the interactive layers feature in Present3D to create a menu show on a remote machine and have this start shows on the display machine. To set this up you need to have a working version of SSH and set up a RSA key to avoid having to enter a password every time.

SSH Set UP for remote login

There is a bug in the standard implementation of SSH in 10.4.2 that effectively disables remote login. To solve this install “openssh” from Fink. Use Fink Commander as normal. Once installed on the two machines test by using terminal to login from the remote machine to the display machine. To do this you need a common network connection and the network name or address of the machine you wish to connect to and the user name for the current Present3D set up. The remote machine name can be obtained by bringing up a finder window and selecting Network - a list of connected machines will appear on the adjacent column, note the name of the machine that you want to connect to and if necessary check the name of the user, type the following, substituting “user name” and DisplayMachineName and responding with “yes” and the user password for the remote machine when prompted. 

% ssh user_name@DisplayMachineName.local 
The authenticity of host '12inch.local (fe80::21a:95ff:fef6:a87e%en1)' can't be established. 
RSA key fingerprint is 93:b5:0d:a6:af:7f:d9:47:c8:73:00:6b:d1:ad:c0:7d. 
Are you sure you want to continue connecting (yes/no)? 
%yes 
Warning: Permanently added 'DisplayMachineName.local,fe80::21a:95ff:fef6:a87e% 
en1' (RSA) to the list of known hosts. 
%Password: 
Last login: Fri Oct  7 08:48:20 2005 
Welcome to DisplayMachineName! 
%

Set up RSA Key to disable passwords for authorised machines

1. Determine your protocol: 

% ssh -V 
OpenSSH_3.8p1, SSH protocols 1.5/2.0, OpenSSL 0.9.7d 17 Mar 2004

2. Select the type of key:

  • A RSA key for use with the SSH 1 protocol.
  • A RSA key for use with the SSH 2 protocol.
  • A DSA key for use with the SSH 2 protocol. (The rest of these notes assume a RSA key for SSH 2 protocol. RSH keys are reportedly stronger)

3. Use ssh-keygen to generate a key: 

% ssh-keygen -t rsa

Follow prompts, but enter an empty passphrase. You can add an passphrase if you want, but you will have to enter a password every time you ssh, and this defeats the purpose of this exercise. This will generate a private key: 

~/.ssh/id_rsa

and a public key: 

~/.ssh/id_rsa.pub

4. Copy the public key to the remote host and store this in: 

~/.ssh/authorized_keys.

(this will be the last time you have to enter a password)

5. Test it: 

% ssh user_name@DisplayMachineName.local

you shouldn't need to enter a password.