Linux Administration Cookbook

The authorized_keys file

When you connect to your remote host, SSH validates the key ID you're providing against a list of authorized_keys.

In our example, we used the ssh-copy-id command to place our key on the remote server. What this actually does is put it in a specific file of the home user you're connecting to.

On our centos2 host, we can find this file in the user's home directory, under .ssh:

[vagrant@centos2 ~]$ pwd/home/vagrant[vagrant@centos2 ~]$ ls .ssh/authorized_keys

Looking inside this file reveals the following:

[vagrant@centos2 ~]$ cat .ssh/authorized_keys ssh-rsa AAAAB3NzaC1yc2EAAAADAQABAAABAQDNkm9JCaRa/5gunzDZ8xO2/xwRvUx03pITH6f4aYziY/j+7o39XnmNyLRVpvh16u9W75ANJeFpBD7lkevluvaFVRQnZGAhuIdGqLHBlGDnVzkzcQGUFc/fcAc9rDAFGa0h7+BF18P0jpOMXfHQu8+7+cBjJ6cW+ztKerG2ali/JLtSHFirXaVTkOKYkwYVfK7z7nmdMsSzgEOsfg5XrylI+ufhGdgWCKtweHsBeAVWjBBbvNaIwgdRVpB1YmLkLgLN7NxRs53OuejwArLS6tvNS+ZBDiSX+was9gErrhGhZ1mdiOMbd3/oTfFEcOiRNOv/+7Tk4P8fJbnO1dzM8Gid ...