Using dropbear is a simple way to access other file systems, whether on Linux or Android.
This is how I setup the Android app SimpleSSHD
On the phone I setup the ssh directory to /storage/0/ssh
I run the app and reset the keys and verify the directory has the dropbear configuration files.
On my linux system I run
ssh-keygen -t rsa Generating public/private rsa key pair. Enter file in which to save the key (/home/simon/.ssh/id_rsa): /home/simon/.ssh/id_rsa already exists. Overwrite (y/n)? y Enter passphrase (empty for no passphrase): Enter same passphrase again: Your identification has been saved in /home/simon/.ssh/id_rsa Your public key has been saved in /home/simon/.ssh/id_rsa.pub
This generates the files, but then I need to copy and rename the file to Android.
cp /home/simon/.ssh/id_rsa.pub /home/simon/authorised_keys
I then copy (using a cable) this authorised keys into the directory on the phone /storage/0/ssh/
I then create a config file in .ssh called config
Host 192.168.0.247 Port 2222 Host f1 Port 2222
This redirects all ssh to port 2222 for the ip address of the phone and the name in /etc/hosts
I run the SSH app on the phone and I can log in with Thunar or via the terminal
ssh f1 :/ $ cd /storage/emulated/0 :/storage/emulated/0 $ ls Android Documents Librera Pictures backups ssh Books Download Movies Power\ Toggles Telegram kindle DCIM FCar Music Signal :/storage/emulated/0 $ exit Connection to f1 closed.
In Thunar you need to supply a full path that is accessible by the user, /storage is not readable.
If this is not the only machine to access the phone you would need to get the authorized_keys file from the phone and append the new key.
cat /home/simon/.ssh/id_rsa.pub >>/home/simon/authorised_keys
Then copy file back into the /storage/emulated/0/ssh directory. All other steps are the same.