(The dropbear server is running in the router and listening at the sshd port.)
The issue is that, from Linux, I'm able to ssh-login into the router with the password, but I'm not able to login with the ssh-agent/public-key. (As a comparison, from that same terminal session where ssh-login into the router with the ssh-agent/public-key fails, I'm able to ssh-login into another Linux box with the ssh-agent/public-key. The SSH_AGENT_PID and the SSH_AUTH_SOCK environment variables are set in that terminal session.)
I don't know if it is that the sshd_authorized_keys= value lacks a new-line at the end (my sshd_authorized_keys=... is a single line, while, as a comparison, the sshd_ed25519_host_key= value does have a new-line at the end: like the empty line after "-----END OPENSSH PRIVATE KEY-----" below:
Joined: 08 May 2018 Posts: 17390 Location: Texas, USA
Posted: Thu Aug 07, 2025 0:10 Post subject:
The problem is that your authorized key(s) is(are) rsa, not ed25519, methinks. RSA keys are no longer supported for key-based authentication with SSH / dropbear in DD-WRT. Create ED25519 key(s) for SSH on your linux box and put that in the authorized keys textbox and remove the RSA key(s).
