Trying to do ssh authentication with key files: server refused our key

Ok, it is fixed however I don't see how this is different from what I tried already.

What I did:

  • generate a key pair with puttygen.exe (length: 1024 bits)
  • load the private key in the PuTTY profile
  • enter the public key in ~/.ssh/authorized_keys in one line (ssh-rsa {your_public_key} with no more than once space between ssh-rsa and your key)
  • chmod 700 ~/.ssh
  • chmod 600 ~/.ssh/authorized_keys
  • chown $USER:$USER ~/.ssh -R
  • change /etc/ssh/sshd_config so it contains AuthorizedKeysFile %h/.ssh/authorized_keys
  • sudo service ssh restart

For troubleshooting do # tail -f /var/log/auth.log.

Thanks for your help!


I just encountered this problem. Despite having the config set correctly as is already mentioned in this thread (permissions on authorized_keys etc.), it turns out I had the public key in the wrong format. It was in the form of:

---- BEGIN SSH2 PUBLIC KEY ----
Comment: "imported-openssh-key"
AAAAB3NzaC1yc2EAAAADAQABAAABAQDUoj0N3vuLpeviGvZTasGQ...
... lPmTrOfVTxI9wjax2JvKcyE0fiNMzXO7qiHJsQM9G9ZB4Lkf71kT
---- END SSH2 PUBLIC KEY ----

Which wasn't working. But got it working having it in the form:

ssh-rsa AAAAB3NzaC1yc2EAAAADAQABAAABAQDU.....j0N3vuLpeviGvZTasGQa1rcJiPXQMW7v3uurb+n94B9MQaaWR0odsg5DJQL92TNenOda5BO1nd08y6+sdLQmHXExTz6X8FzgoVsAkEl3RscxcxHUksiKA9JfTo38vQvG/bPxIHMCuSumCQVA1laf3rO/uOrkcB7iMWhaoi1/z6AbFtPzeh7xjGfInMWwtBI0CsHSRF73VWIxT26w0P+KjafCjSn/7vDO1bT8QHujSQelU/GqaVEvbbvPl1a7POVjKgHLNekolwRKfNeVEewcnmZaoqfHgOKlPmTrOfVTxI9wjax2JvKcyE0fiNMzXO7qiHJsQM9G9ZB4Lkf71kT UserName@HOSTNAME

the problem is that windows uses a different new line than linux, so when copying the key from windows to linux, there is a \n at the end of the line that you can not see on linux in the editor.

If you tail the /var/log/auth.log and try to login, the error is like:

sshd: error: key_read: uudecode AAAAB3N[....]==\n

If you change your key on windows so its in a single line without a new line at the end and copy it then to linux, it should work (did the trick for me).