ssh and git setup

Question

I am attempting to setup a private git server on my local network and I cannot for the life of me figure out what I am doing wrong. I can't seem to get ssh authentication via private key working for the git user.

I have run ssh-keygen on the client to create an rsa pub/private key. I have created the ~/.ssh/authorized_keys file on the server. I have copied the contents of id_rsa.pub over to the authorized_keys file on the server, by using scp to transfer the file to the server and then cat id_rsa.pub > ~/.ssh/authorized_keys on the server to ensure there were no copy errors. I have restarted the ssh daemon.

On the client, the ~/.ssh folder has permissions 700, and the ~/.ssh/id_rsa file has permissions 600. On the server, the ~/.ssh folder has permissions 700, and the ~/.ssh/authorized_keys file has permissions 600.

My server's ssh config at /etc/ssh/sshd_config has the following uncommented lines

Include /etc/ssh/sshd_config.d/*.conf
KbdInteractiveAuthentication no
UsePAM yes
X11Forwarding yes
PrintMotd no
AcceptEnv LANG LC_*
Subsystem sftp  /usr/lib/openssh/sftp-server
PasswordAuthentication yes
Match User git
        PasswordAuthentication no
        PubkeyAuthentication yes

The /etc/ssh/sshd_config.d/ folder is empty. The server is running Ubuntu 22.04.1 LTS. The server's ssh version is OpenSSH_8.9p1 Ubuntu-3ubuntu0.1, OpenSSL 3.0.2 15 Mar 2022

Upon attempting to ssh [email protected] I am greeted with the following
Permission denied (publickey).

What am I missing? I've looked at guides. I've made sure I am copying the key over accurately. I am honestly stumped because I have inserted public keys into the authorized_keys file before on a server with ssh already setup, and it's worked. If I set the sshd config to allow PasswordAuthentication then I can login as the git user fine with the password I have set on it. I do not understand why the public private key auth is not working.

Output of ssh [email protected] -vvv
https://pastebin.com/raw/nJwskYhU

Answer 1

There was an error in /var/log/auth.log which stated:
Authentication refused: bad ownership or modes for directory <home directory>

What I had done is moved the git user's home directory to a new location, and this folder had different than standard permissions and ownership than home directories do by default. I assume this was the problem. Moving the home directory back to what it was fixed the issue. Thank you to Kenster for their comment. I did not think to look for logs on the server side.