using keys for ssh connection
 

I am trying to create public/private keys to connect to my ssh server. I use puttygen/putty, and when I connect, it tells me that the "server refused our key". I ran the following commands:
and added this line to the sshd_config file:
But I still get the same error. The key in the authorized_keys file is all on one line.

EDIT: By the way, I followed this tutorial: https://www.digitalocean.com/communi...nnect-to-a-vps

what's in /var/log/secure or /var/log/auth.log about it? (you also should mention what distro and version you are running)

Raspbian. It's for my Raspberry Pi.
In sshd_config, I have AllowUsers ftpuser.

Anybody have any ideas?

Well you could take out the allowusers directive and see if the lockdown is causing it and it's a syntax issue.

I still get the error that the server refused the key.

ftpuser is in /etc/passwd in the server? (grep ftpuser /etc/passwd)

yes; /var/www:/bin/bash

For sshd_config:
RSAAuthentication yes
PubkeyAuthentication yes
AuthorizedKeysFile %h/.ssh/authorized_keys

Are you able to connect to the server with putty using a password?

yes

You did run these commands as root ?
.ssh dir needs to be in /var/www according to output of greping ftpuser in passwd file
and permissions need to be set as ftpuser

so .ssh should be in /var/www? why is it in the user's home directory?
I did run these, but will run them again. Should the user owner be ftpuser, as well as the group owner?

Yes /var/www is home user dir for ftpuser according to passwd
.ssh should be in user dir according to sshd_config (%h/.ssh)
Yes
Yes, see which group ftpuser belongs to in passwd for fptuser line (4th field)
or more simple, as root : "id ftpuser"

What if I want to allow other users to login?

Eventually users can login to ftpuser account if they have their public keys appended to /var/www/.ssh/authorized_keys file, then login as: ssh ftpuser@server

But it has some security concerns for sure.

Anyway if you tell what specifically your plan is from the start, you'll get more productive answers I think