When configuring SSH keys, it’s crucial to set the correct permissions on the .ssh directory and its contents. Incorrect permissions can prevent SSH from working properly.

Here’s a handy command to check file permissions in numeric format (like 0700, 0600, etc.), which is especially useful when setting up your SSH directory:

stat -c "%a %n" ~/.ssh ~/.ssh/*

This may produce an output like the following if permissions have been set correctly.

700 /home/user/.ssh
644 /home/user/.ssh/authorized_keys
600 /home/user/.ssh/id
644 /home/user/.ssh/id.pub