Linux – SSH without password

linuxssh

I'm unable to ssh without a password for some reason on a new CentOS box.

I've tried following these guides:

But neither are working. I even checked my /etc/ssh/sshd_config file. PubkeyAuthentication yes was originally commented out so I uncommented that line and restarted sshd but still to no avail. Any thoughts of anything else that could be missing?

I'm trying to ssh from server A to server B as root. Thus, logged in as root on one box, then ssh to the next as root without being prompted for a password.

UPDATE

I ran a ssh -v ... but cannot copy/paste into here. Everything looked good until this line:

debug1: Next authentication method:  gssapi-with-mic
debug1: Unspecified GSS failure.  Minor Code may provide more information
Unknown code krb5 195

Best Answer

A small how-to for public key based authentication for CentOS/Red Hat/etc...

On the SSH client:

ssh-keygen # Accept all defaults, do not enter a password.
ssh-copy-id USER@SERVER_IP
restorecon -R ~/.ssh

On the SSH server:

# Login to the server normally (with password)
restorecon -R ~/.ssh

Public key based authentication should now work.

Related Solutions

Ssh authentication nfs

Your ssh client is trying password authentication before public key authentication.

Check your ~/.ssh/config and /etc/ssh/ssh_config files for a PreferredAuthentications entry.

I see similar behavior if I add the following entry to my ~/.ssh/config file:

PreferredAuthentications password,publickey

If you have something like that in either of the aforementioned files, comment it out.

Ssh – How to automate SSH login with password

Don't use a password. Generate a passphrase-less SSH key and push it to your VM.

If you already have an SSH key, you can skip this step… Just hit Enter for the key and both passphrases:

$ ssh-keygen -t rsa -b 2048
Generating public/private rsa key pair.
Enter file in which to save the key (/home/username/.ssh/id_rsa):
Enter passphrase (empty for no passphrase):
Enter same passphrase again:
Your identification has been saved in /home/username/.ssh/id_rsa.
Your public key has been saved in /home/username/.ssh/id_rsa.pub.

Copy your keys to the target server:

$ ssh-copy-id id@server
id@server's password:

Now try logging into the machine, with ssh 'id@server', and check-in:

.ssh/authorized_keys

Note: If you don't have .ssh dir and authorized_keys file, you need to create it first

to make sure we haven’t added extra keys that you weren’t expecting.

Finally, check to log in…

$ ssh id@server

id@server:~$

You may also want to look into using ssh-agent if you want to try keeping your keys protected with a passphrase.

Best Answer

Related Solutions

Ssh authentication nfs

Ssh – How to automate SSH login with password

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