Graphically Browse and Transfer Files to SSH Server Using Various Linux Clients Without SSHFS

Accessing a server via SSH (Secure Shell) is a common method for managing files on remote systems. In this case, the server in question runs Debian 12 and is behind a firewall that requires a proxy jump to be specified. Here's a step-by-step guide on how to set up SSH access with a proxy jump.

Prerequisites

1. Install OpenSSH client on your local machine.
2. Obtain the private key and username for the remote server.

Setting up SSH with Proxy Jump

1. Create a configuration file for the remote server.

   $ touch ~/.ssh/config
   

2. Open the configuration file in a text editor.

   $ nano ~/.ssh/config
   

3. Add the following content to the file, replacing proxy_host and proxy_user with your proxy server's hostname and username, respectively.

   Host remote_server
       HostName proxy_host
       User proxy_user
       ForwardAgent yes
       ForwardX11 yes
       ForwardX11Trusted yes
       IdentityFile ~/.ssh/id_rsa
       ProxyCommand ssh -W %h:%p proxy_user@proxy_host -o StrictHostKeyChecking=no -o UserKnownHostsFile=/dev/null
   

4. Save and close the file.

5. Test the configuration.

   $ ssh remote_server
   

   If everything is set up correctly, you should be able to log in to the remote server without being prompted for a password. The password prompt will appear only when you first log in to the proxy server.

Accessing the Server Files with SSHFS

1. Install SSHFS on your local machine.

   $ sudo apt-get install sshfs
   

2. Mount the remote server's directory.

   $ sshfs remote_user@remote_server:/path/to/remote/directory /local/path
   

   Replace remote_user with your username on the remote server, remote_server:/path/to/remote/directory with the path to the directory you want to access, and /local/path with the local path where you want to mount the remote directory.

3. Unmount the directory when you're done.

   $ fusermount -u /local/path
   $ fusermount -u /local/path
   $ fusermount -d /local/path
   

Now you can access the server's files as if they were on your local machine.

References

1. OpenSSH Manual Page: ssh(1)
2. OpenSSH Manual Page: ssh_config(5)
3. OpenSSH Manual Page: sshfs(1)
4. SSHFS Manual Page: fusermount(8)
5. Debian 12 Release Announcement: https://www.debian.org/News/2021/20210604
6. SSHFS GitHub Repository: https://github.com/libfuse/sshfs
7. SSHFS Manual: https://man.openbsd.org/sshfs.1
8. SSH Proxy Command: https://www.ssh.com/ssh/proxycommand/
9. Debian SSH Server Configuration: https://www.digitalocean.com/community/tutorials/how-to-configure-ssh-key-based-authentication-on-a-debian-10-server
10. SSHFS Troubleshooting: https://github.com/libfuse/sshfs/blob/master/doc/troubleshooting.md