Having reinstalled one of my older laptops I noticed I cannot login using it’s private key. I was sure I backed up the original and properly restored it after reinstalling. I ran ssh -v to get more information:
Roaming not allowed by server caught my eye. What the heck is that?
root@darkstar:~/bin# ssh -v firstname.lastname@example.org OpenSSH_6.6.1, OpenSSL 1.0.1g 7 Apr 2014 debug1: Reading configuration data /etc/ssh/ssh_config debug1: Connecting to 188.8.131.52 [184.108.40.206] port 22. debug1: Connection established. debug1: permanently_set_uid: 0/0 debug1: identity file /root/.ssh/id_rsa type 1 debug1: identity file /root/.ssh/id_rsa-cert type -1 debug1: identity file /root/.ssh/id_dsa type -1 debug1: identity file /root/.ssh/id_dsa-cert type -1 debug1: identity file /root/.ssh/id_ecdsa type -1 debug1: identity file /root/.ssh/id_ecdsa-cert type -1 debug1: identity file /root/.ssh/id_ed25519 type -1 debug1: identity file /root/.ssh/id_ed25519-cert type -1 debug1: Enabling compatibility mode for protocol 2.0 debug1: Local version string SSH-2.0-OpenSSH_6.6.1 debug1: Remote protocol version 2.0, remote software version OpenSSH_6.0p1 Debian-4+deb7u1 debug1: match: OpenSSH_6.0p1 Debian-4+deb7u1 pat OpenSSH* compat 0x04000000 debug1: SSH2_MSG_KEXINIT sent debug1: SSH2_MSG_KEXINIT received debug1: kex: server->client aes128-ctr hmac-md5 none debug1: kex: client->server aes128-ctr hmac-md5 none debug1: sending SSH2_MSG_KEX_ECDH_INIT debug1: expecting SSH2_MSG_KEX_ECDH_REPLY debug1: Server host key: ECDSA xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx debug1: Host '[220.127.116.11]:22' is known and matches the ECDSA host key. debug1: Found key in /root/.ssh/known_hosts:1 debug1: ssh_ecdsa_verify: signature correct debug1: SSH2_MSG_NEWKEYS sent debug1: expecting SSH2_MSG_NEWKEYS debug1: SSH2_MSG_NEWKEYS received debug1: Roaming not allowed by server debug1: SSH2_MSG_SERVICE_REQUEST sent debug1: SSH2_MSG_SERVICE_ACCEPT received debug1: Authentications that can continue: publickey debug1: Next authentication method: publickey debug1: Offering RSA public key: /root/.ssh/id_rsa debug1: Authentications that can continue: publickey debug1: Trying private key: /root/.ssh/id_dsa debug1: Trying private key: /root/.ssh/id_ecdsa debug1: Trying private key: /root/.ssh/id_ed25519 debug1: No more authentication methods to try. Permission denied (publickey).
Than I realized that before restoring the backed-up private key I generated a pair with
ssh-keygen as I always do when installing a new system. This meant that I had the private key I restored but the public key was the one generated beforehand. I removed
id_rsa.pub and this fixed it.