ssh public key authentication

Question

I have tried to configure ssh to use public key authentication

The link

/etc/ssh/sshd_config has got this parameters.

RSAAuthentication yes
PubkeyAuthentication yes
AuthorizedKeysFile  .ssh/authorized_keys

PasswordAuthentication yes

But I'm still being prompted for password. If I use

PasswordAuthentication no

I can't login

Any suggestion?

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It works but only for root user.

My problem was, I had this parameter

PermitRootLogin no.

I can login with keys with root user if I use

PermitRootLogin yes.

In the system there is only a /root/.ssh directory an authorized_keys file in this directory

How can I add this to other users, if there isn't, in this system, a home/$USER/.ssh directory and authorized_keys file for each user?

Is there a way to configure for each user? I will need diferent authorized_keys files for each user.

Is possible to configure for a different hosts, domains or ips? similar to httpd.conf

Answer 1

Key authentication is always attempted before password authentication, so if you're being prompted for a password then key authentication has failed. The most common cause for this is incorrect ownership or permission on the client and server side files.

On both the client and server, the ~/.ssh directory must be owned and only accessible to you:

chown -R $USER ~/.ssh
chmod u=rwX,g=,o= ~/.ssh

On the client the private key must be owned and only accessible to you:

chmod u=rwX,g=,o= ~/.ssh/id_rsa

On the server the authorized keys file must be owned and only accessible to you:

chmod u=rwX,g=,o= ~/.ssh/authorized_keys