HowTo: Revoke OpenSSH Keys and Disable User Access

in Categories last updated November 6, 2012

Many users are using ssh to log into a remote machine and append the indicated identity file to machine’s ~/.ssh/authorized_keys file. I recently moved one of my server, and I would like to revoke openssh keys and disable user access under Linux operating systems. How do I revoke OpenSSH keys under Unix or Linux operating systems?

Linux / Unix: scp Copy All Hidden Dot Files

in Categories , last updated April 2, 2012

I‘m using scp command to copy files from one server to another server. The problem is that I’m unable to copy all hidden files (such as .bash_history). How do I copy hidden files using the scp command under Unix like operating systems?

Force SSH Client To Use Given Private Key ( identity file )

in Categories last updated May 17, 2010

Recently, my desktop hard disk crashed. So I reinstalled Linux and created a new set of private RSA keys for authentication. However, two of my remote UNIX servers still uses old DSA keys. I do not remember root password for those servers. I do have backup of private and public DSA keys and currently stored in /backup/home/user/.ssh/id_dsa and /backup/home/user/.ssh/id_dsa.pub. How do I force my ssh clients to use identity file /backup/home/user/.ssh/id_dsa to get back to my remote UNIX servers?