I am trying to recreate the ssh-server host keys.
I have at least two ways to do this:
This works fine, but I cannot give the key length then. I want for example 4096 for the RSA key.
Manually with ssh-keygen
sudo ssh-keygen -f /etc/ssh/ssh_host_rsa_key -N 'myverylongpasswordhere' -b 4096 -t rsa
This recreates me the keys, but after restarting the server, I receive the following error message:
could not load host key: /etc/ssh/ssh_host_rsa_key
so I checked the sshd_config file whats in there:
matches perfectly. So, I checked the owner and rights to all my keys
-rw------- 1 root root 3326 Mär 24 08:57 ssh_host_rsa_key
When I remove all keys and recreate them with
dpkg-reconfigure openssh-server, the keys are smaller and having the same file-rights like above.
Question: How can I use
dpkg-reconfigure with keylengh 4096 for RSA?