I recently set up a new Synology NAS and (unsuccessfully) tried to replicate my public key SSH access on the new system. I made sure that:
- my local SSH config uses the same private key to login on both Synology systems
- both Synology systems have the same (corresponding) public key in .ssh/authorized_keys
- /etc/ssh/sshd_config is synchronized on both Synology systems (i.e. allows PubKeyAuthentication) and the service was restarted to make sure the correct settings are used
- permissions are set properly (700 and 600) for .ssh/ and authorized_keys on both Synology systems
On the old Synology, ssh -vvv yields
debug1: Offering public key: /Users/xxx/.ssh/synology_key RSA SHA256:xxxx explicit
debug3: send packet: type 50
debug2: we sent a publickey packet, wait for reply
debug3: receive packet: type 60
debug1: Server accepts key: /Users/xxx/.ssh/synology_key RSA SHA256:xxxx explicit
but on the new one, the same key is rejected
debug1: Offering public key: /Users/xxx/.ssh/synology_key RSA SHA256:xxxx explicit
debug3: send packet: type 50
debug2: we sent a publickey packet, wait for reply
debug3: receive packet: type 51
debug1: Authentications that can continue: publickey,password
debug2: we did not send a packet, disable method
debug1: No more authentication methods to try.
[email protected]: Permission denied (publickey,password).
SSH login using my password works on both systems. What else could I check to debug? Thanks!