System-wide authorized_keys

Question

SSH auth by RSA-key: ~/.ssh/authorized_keys. Okay.

Is there a way to set a system-wide authorized key so I can login to any account, including the newly created ones?

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The reason: i've got a server and am the only admin. User accounts are used to isolate web-sites from each other just in case any of them is hacked.

I use SFTP and create new accounts often, thus, i'm tired of copying ~/.ssh/authorized_keys :)

Answer 1

To login to ANY account?

As an administrator, it should be sufficient for you to login as yourself, and then sudo to the account, but ONLY if necessary.

This approach is a serious security issue, as if that single key that you have for all accounts is stolen, then your system is fully compromised.

I feel there are ethical considerations as you are not identifying yourself in any way that you are acting for the owner. Files might be personal. If one is not all that ethical, one could send emails as the account owner and it would not be traceable.

Answer 2

On most Linux systems, the /etc/skel directory is used to populate the home directory of any new account. If you add a .ssh directory with your authorized_keys file to /etc/skel then you will be able to login to any new account.

For existing accounts, you can write a script to add your key to all of the authorized_keys files on the system.