I can add a passwordless id_ed25519 file locally using ssh-add -k, but not on my remote server.
Locally:
☁ ~ ssh-add -l
The agent has no identities.
☁ ~ ssh-add -k ~/.ssh/id_ed25519
Identity added: ~/.ssh/id_ed25519 ([email protected])
☁ ~ ssh-add -l
256 SHA256:.... [email protected] (ED25519)
Locally my OS is not bothered that this is a passwordless key, and does not prompt for a password. On the remote server I get prompted for a password and when I hit ENTER on the empty line for the passwordless key, the process exits and nothing is added:
On my remote server, I can't add the same key in the same way:
[app@... ~]$ ssh-add -l
The agent has no identities.
[app@... ~]$ ssh-add -k ~/.ssh/id_ed25519
Enter passphrase for /home/app/.ssh/id_ed25519:
[app@... ~]$ ssh-add -l
The agent has no identities.
I don't understand what has changed particularly, since this used to work on my server, albeit with a different key (recently changed from rsa to ed25519).
I don't want to set this up a key with a password as this is part of a fix for an automated process that used to work. I want to know why ssh-add might be having problems on one machine and not the other, with the same key.
