I'm trying to get openssh-server to work with public key authentication.
Since this isn't working I've been trying to isolate the issue. To begin with, I'm limiting this to my LAN, so it's not a firewall issue. I have DropBear working on port 22 with both password and public key authentication. With openssh-server I have password authentication working on port 2222 (but not public key). Finally, I get the same results when I use a MacBook and an Ubuntu 20.04 PC and my authorized_keys files are identical between /etc/dropbear and /etc/ssh.
~/.ssh/config (password only):
Host porch 192.168.1.1 Ciphers aes256-ctr MACs hmac-sha2-256 PasswordAuthentication yes Protocol 2
~/.ssh/config (public key only):
Host porch 192.168.1.1 Ciphers aes256-ctr HostKeyAlgorithms ssh-rsa KexAlgorithms firstname.lastname@example.org MACs hmac-sha2-256 IdentityFile ~/.ssh/id_rsa PasswordAuthentication no Protocol 2
/etc/ssh/sshd_config (password only)
ChallengeResponseAuthentication no PasswordAuthentication yes PermitRootLogin yes Port 2222 Protocol 2 Ciphers aes256-ctr MACs hmac-sha2-256
/etc/ssh/sshd_config (public key only)
ChallengeResponseAuthentication no PasswordAuthentication no PermitRootLogin yes Port 2222 Protocol 2 PubkeyAuthentication yes Ciphers aes256-ctr HostKeyAlgorithms ssh-rsa KexAlgorithms email@example.com MACs hmac-sha2-256