How to test RSA Keys in AlmaLinux 9 ?

/ By / Linux / almalinux, linux, RSA

To test if your RSA keys (public and private) can authenticate an SSH session on your AlmaLinux 9 server, you can follow these steps:

Step 1: Ensure the Public Key is on the Server

  1. Place your public key in the ~/.ssh/authorized_keys file for the user you want to SSH into. Make sure it’s set up like this:
cat your_public_key_file.pub >> ~/.ssh/authorized_keys
  1. Ensure the permissions are correct:
chmod 600 ~/.ssh/authorized_keys
chmod 700 ~/.ssh

Step 2: Test SSH Login Using the Private Key

  1. Use the following command to test SSH login with your private key:
ssh -i /path/to/your_private_key user@your_server_ip

Replace /path/to/your_private_key with the actual path to your private key file, user with the appropriate username, and your_server_ip with the IP address or domain of your server.

Step 3: Troubleshooting

If you encounter issues:

  1. Check SSH Daemon Configuration: Ensure that PasswordAuthentication no and PubkeyAuthentication yes are set in /etc/ssh/sshd_config.
  2. Reload SSH Daemon: After modifying the configuration, restart SSH:

sudo systemctl reload sshd

  1. Review SSH Logs: If the login fails, check /var/log/secure or /var/log/auth.log for detailed error messages.

Let me know if you encounter any specific issues, and I can help troubleshoot further.

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