1. OpenSSH keyfile format doesn't play with gnome-keyring daemon

    If you use the OpenSSH keyfile format (ssh-keygen -o or using Ed25519 keys) and using gnome-keyring you may get:

    sr4l@Lars-Laptop:~$ ssh user@server
    sign_and_send_pubkey: signing failed: agent refused operation
    Permission denied (publickey).
    

    This error message cost me a lot of time because on some PCs it does work on others it doesn't. Later I discovered that the problem only occurred if the keys have the default name ~/ssh/id_rsa. Later I found similar reports leading to gnome-keyring daemon.

    Solutions:

    • Deactivate gnome-keyring entirely
    • Only deactivate the gnome-keyring SSH backend
    • Safe your keyfiles with a non-default name and use ssh-add /path …

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