SSH root nopassword failure

snoopy1 · 03-25-2009, 07:18 PM

Hallo everyone.

I need to get SSH working with remote logins for root and no password.

It's an internal network where I dont have to worry about the security concerns. The server "Linnis" is added to the workstations hosts.equiv and I removed localhost from that file, so SSH should only listen to "Linnis".

I can login as root or any user from the server to workstation fine. When I set the no password for root option in /etc/ssh/sshd_config it still asks for the password however whatever I type will result in a "permission denied" error.

Anyone had this issue and how did you solve it?

PS) Pam over SSH is OFF. I tried "accept zero length passwords" but to no joy.

Cheers,

Andrew

BrianK · 03-25-2009, 08:56 PM

I use public key authentication. This quote comes from somewhere on LQ:

Quote:

A single command on the client A does this (replace SERVERB by the correct machine name or IP address of server B ):

Code:

ssh-keygen -t dsa -f ~/.ssh/identity && cat ~/.ssh/identity.pub | ssh SERVERB 'sh -c "cat - >>~/.ssh/authorized_keys2 && chmod 600 ~/.ssh/authorized_keys2"'

... or, if you've already generated your public keys:

Code:

cat ~/.ssh/identity.pub | ssh SERVERB 'sh -c "cat - >>~/.ssh/authorized_keys2 && chmod 600 ~/.ssh/authorized_keys2"'

edited to add: Of course, you would want to do "... ssh root@SERVERB ..."

snoopy1 · 03-26-2009, 09:27 AM

Could you alaborate on what this is doing and why it will solve the problem?

Cheers,
Andrew

TB0ne · 03-26-2009, 11:09 AM

Quote:

Originally Posted by snoopy1

Could you alaborate on what this is doing and why it will solve the problem?

Cheers,
Andrew

Sure...to get passwordless logins working, you need to establish a 'trust' between the two systems.

The first command generates the dsa key (although I'd do rsa personally), and sends it to the remote machine, putting it in the correct user-file on the remote system.

The second assumes you've already generated the key, and just copies it over. Either way, the remote machine now has a 'key', from your local machine. Once they handshake, SSH recognizes that 'trust', and allows the user to connect, without a password, since he's 'recognized' by the key.

Also, pretty slick command-line BrianK...nice command-chaining.