I am trying to connect via SSH to my ubuntu server with public key authentication. For some reasons I get an "Permission denied (publickey)." on the client, whenever I execute
ssh -i ~/.ssh/id_rsa <username>@<ip> -p <port>.
The auth.log on my server has the following output:
sshd: Connection closed by <client-ip> [preauth]
But as soon as I login physically on my server, with the samer username, the following ssh connection from my client successes. But as soon as I logout physically, the next ssh session from my client fails.
# What ports, IPs and protocols we listen for Port <port> # Use these options to restrict which interfaces/protocols sshd will bind to #ListenAddress :: #ListenAddress 0.0.0.0 Protocol 2 # HostKeys for protocol version 2 HostKey /etc/ssh/ssh_host_rsa_key HostKey /etc/ssh/ssh_host_dsa_key HostKey /etc/ssh/ssh_host_ecdsa_key HostKey /etc/ssh/ssh_host_ed25519_key #Privilege Separation is turned on for security UsePrivilegeSeparation yes # Lifetime and size of ephemeral version 1 server key KeyRegenerationInterval 3600 ServerKeyBits 1024 # Logging SyslogFacility AUTH LogLevel INFO # Authentication: LoginGraceTime 120 PermitRootLogin no StrictModes yes RSAAuthentication yes PubkeyAuthentication yes AuthorizedKeysFile %h/.ssh/authorized_keys # Don't read the user's ~/.rhosts and ~/.shosts files IgnoreRhosts yes # For this to work you will also need host keys in /etc/ssh_known_hosts RhostsRSAAuthentication no # similar for protocol version 2 HostbasedAuthentication no PermitEmptyPasswords no ChallengeResponseAuthentication no PasswordAuthentication no X11Forwarding yes X11DisplayOffset 10 PrintMotd no PrintLastLog yes TCPKeepAlive yes #UseLogin no AcceptEnv LANG LC_* Subsystem sftp /usr/lib/openssh/sftp-server UsePAM no ClientAliveInterval 30 ClientAliveCountMax 99999
Any clues why this could happen? Or do you have any recommendations according security? Thank you!