simplesshd/app/src/main/java/org/galexander/sshd/SimpleSSHD.java

package org.galexander.sshd;

import android.app.Activity;
import android.app.AlertDialog;
import android.os.Bundle;
import android.content.Context;
import android.content.SharedPreferences;
import android.content.Intent;
import android.content.DialogInterface;
import android.content.pm.PackageManager;
import android.text.ClipboardManager;
import android.view.View;
import android.view.Menu;
import android.view.MenuItem;
import android.widget.Button;
import android.widget.CheckBox;
import android.widget.EditText;
import android.widget.TextView;
import android.widget.Toast;
import android.net.Uri;
import java.io.File;
import java.io.FileReader;
import java.io.BufferedReader;
import java.net.NetworkInterface;
import java.net.InetAddress;
import java.util.Collections;
import java.util.List;
import android.Manifest;

public class SimpleSSHD extends Activity
{
	private static final Object lock = new Object();
	private EditText log_view;
	private Button startstop_view;
	private TextView ip_view;
	public static SimpleSSHD curr = null;
	public static String app_private = null;
	private UpdaterThread updater = null;
	public static boolean is_tv = false;

	public void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		app_private = getFilesDir().toString();
		Prefs.init(this);
		setContentView(is_tv ? R.layout.main_tv : R.layout.main);
		log_view = (EditText)findViewById(R.id.log);
		startstop_view = (Button)findViewById(R.id.startstop);
		ip_view = (TextView)findViewById(R.id.ip);
	}

	public void onResume() {
		super.onResume();
		synchronized (lock) {
			curr = this;
		}
		permission_startup();
		update_startstop_prime();
		updater = new UpdaterThread();
		updater.start();
		ip_view.setText(get_ip(true));

		if (Prefs.get_onopen() && !SimpleSSHDService.is_started()) {
			SimpleSSHDService.do_startService(this, /*stop=*/false);
		}
	}

	public void onPause() {
		synchronized (lock) {
			curr = null;
		}
		updater.interrupt();
		super.onPause();
	}

	public boolean onCreateOptionsMenu(Menu menu) {
		getMenuInflater().inflate(R.menu.main_menu, menu);
		return true;
	}

	public boolean onOptionsItemSelected(MenuItem item) {
		switch (item.getItemId()) {
			case R.id.settings:
				settings_clicked(null);
				return true;
			case R.id.copypriv:
				copypriv_clicked(null);
				return true;
			case R.id.resetkeys:
				resetkeys_clicked(null);
				return true;
			case R.id.trypermission:
				permission_clicked(null);
				return true;
			case R.id.doc:
				doc_clicked(null);
				return true;
			case R.id.about:
				about_clicked(null);
				return true;
			default:
				return super.onOptionsItemSelected(item);
		}
	}


	/* these can be called as the _clicked() variant on Android TV, or
	 * through the options menu on regular Android */
	public void settings_clicked(View v) {
		startActivity(new Intent(this, Settings.class));
	}
	public void copypriv_clicked(View v) {
		copy_app_private();
	}
	public void resetkeys_clicked(View v) {
		reset_keys();
	}
	public void permission_clicked(View v) {
		permission_menu();
	}
	public void doc_clicked(View v) {
		try {
			Intent i = new Intent(Intent.ACTION_VIEW);
			i.setData(Uri.parse(DocActivity.url));
			startActivity(i);
		} catch (Exception e) {
			startActivity(new Intent(this, (is_tv
				? DocActivityTV.class : DocActivity.class)));
		}
	}
	public void about_clicked(View v) {
		AlertDialog.Builder b = new AlertDialog.Builder(this);
		b.setCancelable(true);
		b.setPositiveButton("OK",
			new DialogInterface.OnClickListener() {
				public void onClick(DialogInterface di, int which) { }
			});
		b.setIcon(android.R.drawable.ic_dialog_info);
		b.setTitle("About");
		b.setMessage(
"SimpleSSHD version " + my_version() +
"\ndropbear 2020.81" +
"\nscp/sftp from OpenSSH 6.7p1" +
"\nrsync 3.1.1");
		b.show();
	}


	private void update_startstop_prime() {
		if (SimpleSSHDService.is_started()) {
			startstop_view.setText(
				Prefs.get_onopen() ? "QUIT" : "STOP");
			startstop_view.setTextColor(
				is_tv ? 0xFFFF6666 : 0xFF881111);
		} else {
			startstop_view.setText("START");
			startstop_view.setTextColor(
				is_tv ? 0xFF44FF44 : 0xFF118811);
		}
	}

	private static void run_on_ui(Runnable r) {
		synchronized (lock) {
			if (curr != null) {
				curr.runOnUiThread(r);
			}
		}
	}

	public static void update_startstop() {
		run_on_ui(new Runnable() { public void run() {
			synchronized (lock) {
				if (curr != null) {
					curr.update_startstop_prime();
				}
			}
		} });
	}

	public void startstop_clicked(View v) {
		boolean already_started = SimpleSSHDService.is_started();
		SimpleSSHDService.do_startService(this, already_started);
		if (already_started && Prefs.get_onopen()) {
			finish();
		}
	}

	private void update_log_prime() {
		String[] lines = new String[50];
		int curr_line = 0;
		boolean wrapped = false;
		try {
			File f = new File(Prefs.get_path(), "dropbear.err");
			if (f.exists()) {
				BufferedReader r = new BufferedReader(
							new FileReader(f));
				try {
					String l;
					while ((l = r.readLine()) != null) {
						lines[curr_line++] = l;
						if (curr_line >= lines.length) {
							curr_line = 0;
							wrapped = true;
						}
					}
				} finally {
					r.close();
				}
			}
		} catch (Exception e) { }
		int i;
		i = (wrapped ? curr_line : 0);
		String output = "";
		do {
			output = output + lines[i] + "\n";
			i++;
			i %= lines.length;
		} while (i != curr_line);
		log_view.setText(output);
		log_view.setSelection(output.length());
	}

	public static void update_log() {
		run_on_ui(new Runnable() { public void run() {
			synchronized (lock) {
				if (curr != null) {
					curr.update_log_prime();
				}
			}
		} });
	}

	public static String get_ip(boolean pretty) {
		String ret = "";
		int num_ips = 0;
		try {
			List<NetworkInterface> interfaces = Collections.list(NetworkInterface.getNetworkInterfaces());
			for (NetworkInterface intf : interfaces) {
				List<InetAddress> addrs = Collections.list(intf.getInetAddresses());
				for (InetAddress addr : addrs) {
					String ip = addr.getHostAddress();
					if (!addr.isLoopbackAddress() &&
					    !ip.startsWith("fe80")) {
						int i = ip.indexOf('%');
						if (i != -1) {
							ip = ip.substring(0,i);
						}
						if (!pretty) {
							return ip;
						}
						if (num_ips++ >= 5) {
							return ret+"...";
						}
						if (num_ips > 1) {
							ret += "\n";
						}
						ret += "IP: " + ip;
					}
				}
			}
		} catch (Exception ex) { } // for now eat exceptions
		return ret;
	}

	private void copy_app_private() {
		new AlertDialog.Builder(this)
		  .setCancelable(true)
		  .setPositiveButton("OK",
			new DialogInterface.OnClickListener() {
				public void onClick(DialogInterface di,
					int which) { }
			})
		  .setNegativeButton("Copy",
			new DialogInterface.OnClickListener() {
				public void onClick(DialogInterface di,
					int which) {
					ClipboardManager cl = (ClipboardManager)
						getSystemService(
						Context.CLIPBOARD_SERVICE);
					if (cl != null) {
						cl.setText(app_private);
					}
				}
			})
		  .setIcon(android.R.drawable.ic_dialog_info)
		  .setTitle("App-private path")
		  .setMessage(app_private)
		  .show();
	}

	private void do_reset_keys() {
		new File(Prefs.get_path(), "authorized_keys").delete();
	}

	private void reset_keys() {
		AlertDialog.Builder b = new AlertDialog.Builder(this);
		b.setCancelable(true);
		b.setPositiveButton("Yes",
			new DialogInterface.OnClickListener() {
				public void onClick(DialogInterface di,
					int which) { do_reset_keys(); }
			});
		b.setNegativeButton("No",
			new DialogInterface.OnClickListener() {
				public void onClick(DialogInterface di,
					int which) { }
			});
		b.setIcon(android.R.drawable.ic_dialog_alert);
		b.setTitle("Reset Keys");
		b.setMessage("Delete the authorized_keys file? (then you will only be able to login with single-use passwords)");
		b.show();
	}

	public String my_version() {
		try {
			return getPackageManager().getPackageInfo(getPackageName(), 0).versionName;
		} catch (Exception e) {
			return "UNKNOWN";
		}
	}

	private void permission_startup() {
		if (android.os.Build.VERSION.SDK_INT < 23) {
			return;
		}
		if (checkSelfPermission(Manifest.permission.WRITE_EXTERNAL_STORAGE) == PackageManager.PERMISSION_GRANTED) {
			return;
		}
		if (Prefs.get_requested()) {	/* already asked once */
			return;
		}
		requestPermissions(new String[] { Manifest.permission.WRITE_EXTERNAL_STORAGE }, 0);
	}

	private void toast(String s) {
		Toast.makeText(this, s, Toast.LENGTH_LONG).show();
	}

	private void permission_menu() {
		if (android.os.Build.VERSION.SDK_INT < 23) {
			toast("Your phone uses an Android version that grants external storage access by default.");
			return;
		}
		if (checkSelfPermission(Manifest.permission.WRITE_EXTERNAL_STORAGE) == PackageManager.PERMISSION_GRANTED) {
			toast("External storage permission already granted.");
			return;
		}
		requestPermissions(new String[] { Manifest.permission.WRITE_EXTERNAL_STORAGE }, 0);
	}

	public void onRequestPermissionsResult(int code, String[] perms, int[] results) {
		Prefs.set_requested();	/* whatever result, don't ask again */
	}
}