OpenSSH Change a Passphrase With ssh-keygen command

How do I change OpenSSH passphrase for one of my private keys under Linux, OpenBSD, FreeBSD, Apple OS X or Unix like operating systems?

You need to use the ssh-keygen command to generates, change manages and converts authentication keys for ssh. You should the see following files at $HOME/.ssh or ~/.ssh directory i.e. /home/you/.ssh/. You can use the ls -l $HOME/.ssh/ command to see the following files:

=> id_dsa : DSA authentication identity of the user

=> id_dsa.pub : DSA public key for authentication

=> id_rsa : RSA authentication identity of the user

=> id_rsa.pub : RSA public key for authentication

Changing a Passphrase with ssh-keygen

The -p option requests changing the passphrase of a private key file instead of creating a new private key. The program will prompt for the file containing the private key, for the old passphrase, and twice for the new passphrase. Use -f {filename} option to specifies the filename of the key file. For example, change directory to $HOME/.ssh. Open the Terminal app and then type:
$ cd ~/.ssh/

To change DSA passphrase, enter:
$ ssh-keygen -f id_dsa -p

To change RSA passphrase, enter:
$ ssh-keygen -f id_rsa -p
Sample outputs:

Animated gif 01: Changing your openssh passphrase

References
  • See ssh-keygen(1) man page for information on command line options.

Posted by: SXI ADMIN

The author is the creator of SXI LLC and a seasoned sysadmin, DevOps engineer, and a trainer for the Linux operating system/Unix shell scripting. Get the latest tutorials on SysAdmin, Linux/Unix and open source topics via RSS/XML feed or weekly email newsletter.