android: Add interface for VPN data source

Change VPN profile source to an interface. Preparation to allow managed
configurations as a second source.

src/frontends/android/app/src/main/java/org/strongswan/android/data/VpnProfileDataSource.java

@@ -1,4 +1,5 @@
 /*
+ * Copyright (C) 2023 Relution GmbH
  * Copyright (C) 2012-2019 Tobias Brunner
  * Copyright (C) 2012 Giuliano Grassi
  * Copyright (C) 2012 Ralf Sager
@@ -18,298 +19,50 @@
 
 package org.strongswan.android.data;
 
-import android.content.ContentValues;
-import android.content.Context;
-import android.database.Cursor;
 import android.database.SQLException;
-import android.database.sqlite.SQLiteDatabase;
-import android.database.sqlite.SQLiteOpenHelper;
-import android.database.sqlite.SQLiteQueryBuilder;
-import android.util.Log;
 
-import java.util.ArrayList;
 import java.util.List;
 import java.util.UUID;
 
-public class VpnProfileDataSource
+public interface VpnProfileDataSource
 {
-	private static final String TAG = VpnProfileDataSource.class.getSimpleName();
-	public static final String KEY_ID = "_id";
-	public static final String KEY_UUID = "_uuid";
-	public static final String KEY_NAME = "name";
-	public static final String KEY_GATEWAY = "gateway";
-	public static final String KEY_VPN_TYPE = "vpn_type";
-	public static final String KEY_USERNAME = "username";
-	public static final String KEY_PASSWORD = "password";
-	public static final String KEY_CERTIFICATE = "certificate";
-	public static final String KEY_USER_CERTIFICATE = "user_certificate";
-	public static final String KEY_MTU = "mtu";
-	public static final String KEY_PORT = "port";
-	public static final String KEY_SPLIT_TUNNELING = "split_tunneling";
-	public static final String KEY_LOCAL_ID = "local_id";
-	public static final String KEY_REMOTE_ID = "remote_id";
-	public static final String KEY_EXCLUDED_SUBNETS = "excluded_subnets";
-	public static final String KEY_INCLUDED_SUBNETS = "included_subnets";
-	public static final String KEY_SELECTED_APPS = "selected_apps";
-	public static final String KEY_SELECTED_APPS_LIST = "selected_apps_list";
-	public static final String KEY_NAT_KEEPALIVE = "nat_keepalive";
-	public static final String KEY_FLAGS = "flags";
-	public static final String KEY_IKE_PROPOSAL = "ike_proposal";
-	public static final String KEY_ESP_PROPOSAL = "esp_proposal";
-	public static final String KEY_DNS_SERVERS = "dns_servers";
-
-	private DatabaseHelper mDbHelper;
-	private SQLiteDatabase mDatabase;
-	private final Context mContext;
-
-	private static final String DATABASE_NAME = "strongswan.db";
-	private static final String TABLE_VPNPROFILE = "vpnprofile";
-
-	private static final int DATABASE_VERSION = 17;
-
-	public static final DbColumn[] COLUMNS = new DbColumn[] {
-								new DbColumn(KEY_ID, "INTEGER PRIMARY KEY AUTOINCREMENT", 1),
-								new DbColumn(KEY_UUID, "TEXT UNIQUE", 9),
-								new DbColumn(KEY_NAME, "TEXT NOT NULL", 1),
-								new DbColumn(KEY_GATEWAY, "TEXT NOT NULL", 1),
-								new DbColumn(KEY_VPN_TYPE, "TEXT NOT NULL", 3),
-								new DbColumn(KEY_USERNAME, "TEXT", 1),
-								new DbColumn(KEY_PASSWORD, "TEXT", 1),
-								new DbColumn(KEY_CERTIFICATE, "TEXT", 1),
-								new DbColumn(KEY_USER_CERTIFICATE, "TEXT", 2),
-								new DbColumn(KEY_MTU, "INTEGER", 5),
-								new DbColumn(KEY_PORT, "INTEGER", 5),
-								new DbColumn(KEY_SPLIT_TUNNELING, "INTEGER", 7),
-								new DbColumn(KEY_LOCAL_ID, "TEXT", 8),
-								new DbColumn(KEY_REMOTE_ID, "TEXT", 8),
-								new DbColumn(KEY_EXCLUDED_SUBNETS, "TEXT", 10),
-								new DbColumn(KEY_INCLUDED_SUBNETS, "TEXT", 11),
-								new DbColumn(KEY_SELECTED_APPS, "INTEGER", 12),
-								new DbColumn(KEY_SELECTED_APPS_LIST, "TEXT", 12),
-								new DbColumn(KEY_NAT_KEEPALIVE, "INTEGER", 13),
-								new DbColumn(KEY_FLAGS, "INTEGER", 14),
-								new DbColumn(KEY_IKE_PROPOSAL, "TEXT", 15),
-								new DbColumn(KEY_ESP_PROPOSAL, "TEXT", 15),
-								new DbColumn(KEY_DNS_SERVERS, "TEXT", 17),
-							};
-
-	private static final String[] ALL_COLUMNS = getColumns(DATABASE_VERSION);
-
-	private static String getDatabaseCreate(int version)
-	{
-		boolean first = true;
-		StringBuilder create = new StringBuilder("CREATE TABLE ");
-		create.append(TABLE_VPNPROFILE);
-		create.append(" (");
-		for (DbColumn column : COLUMNS)
-		{
-			if (column.Since <= version)
-			{
-				if (!first)
-				{
-					create.append(",");
-				}
-				first = false;
-				create.append(column.Name);
-				create.append(" ");
-				create.append(column.Type);
-			}
-		}
-		create.append(");");
-		return create.toString();
-	}
-
-	private static String[] getColumns(int version)
-	{
-		ArrayList<String> columns = new ArrayList<>();
-		for (DbColumn column : COLUMNS)
-		{
-			if (column.Since <= version)
-			{
-				columns.add(column.Name);
-			}
-		}
-		return columns.toArray(new String[0]);
-	}
-
-	private static class DatabaseHelper extends SQLiteOpenHelper
-	{
-		public DatabaseHelper(Context context)
-		{
-			super(context, DATABASE_NAME, null, DATABASE_VERSION);
-		}
-
-		@Override
-		public void onCreate(SQLiteDatabase database)
-		{
-			database.execSQL(getDatabaseCreate(DATABASE_VERSION));
-		}
-
-		@Override
-		public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion)
-		{
-			Log.w(TAG, "Upgrading database from version " + oldVersion +
-				  " to " + newVersion);
-			if (oldVersion < 2)
-			{
-				db.execSQL("ALTER TABLE " + TABLE_VPNPROFILE + " ADD " + KEY_USER_CERTIFICATE +
-						   " TEXT;");
-			}
-			if (oldVersion < 3)
-			{
-				db.execSQL("ALTER TABLE " + TABLE_VPNPROFILE + " ADD " + KEY_VPN_TYPE +
-						   " TEXT DEFAULT '';");
-			}
-			if (oldVersion < 4)
-			{	/* remove NOT NULL constraint from username column */
-				updateColumns(db, 4);
-			}
-			if (oldVersion < 5)
-			{
-				db.execSQL("ALTER TABLE " + TABLE_VPNPROFILE + " ADD " + KEY_MTU +
-						   " INTEGER;");
-			}
-			if (oldVersion < 6)
-			{
-				db.execSQL("ALTER TABLE " + TABLE_VPNPROFILE + " ADD " + KEY_PORT +
-						   " INTEGER;");
-			}
-			if (oldVersion < 7)
-			{
-				db.execSQL("ALTER TABLE " + TABLE_VPNPROFILE + " ADD " + KEY_SPLIT_TUNNELING +
-						   " INTEGER;");
-			}
-			if (oldVersion < 8)
-			{
-				db.execSQL("ALTER TABLE " + TABLE_VPNPROFILE + " ADD " + KEY_LOCAL_ID +
-						   " TEXT;");
-				db.execSQL("ALTER TABLE " + TABLE_VPNPROFILE + " ADD " + KEY_REMOTE_ID +
-						   " TEXT;");
-			}
-			if (oldVersion < 9)
-			{
-				db.execSQL("ALTER TABLE " + TABLE_VPNPROFILE + " ADD " + KEY_UUID +
-						   " TEXT;");
-				updateColumns(db, 9);
-			}
-			if (oldVersion < 10)
-			{
-				db.execSQL("ALTER TABLE " + TABLE_VPNPROFILE + " ADD " + KEY_EXCLUDED_SUBNETS +
-						   " TEXT;");
-			}
-			if (oldVersion < 11)
-			{
-				db.execSQL("ALTER TABLE " + TABLE_VPNPROFILE + " ADD " + KEY_INCLUDED_SUBNETS +
-						   " TEXT;");
-			}
-			if (oldVersion < 12)
-			{
-				db.execSQL("ALTER TABLE " + TABLE_VPNPROFILE + " ADD " + KEY_SELECTED_APPS +
-						   " INTEGER;");
-				db.execSQL("ALTER TABLE " + TABLE_VPNPROFILE + " ADD " + KEY_SELECTED_APPS_LIST +
-						   " TEXT;");
-			}
-			if (oldVersion < 13)
-			{
-				db.execSQL("ALTER TABLE " + TABLE_VPNPROFILE + " ADD " + KEY_NAT_KEEPALIVE +
-						   " INTEGER;");
-			}
-			if (oldVersion < 14)
-			{
-				db.execSQL("ALTER TABLE " + TABLE_VPNPROFILE + " ADD " + KEY_FLAGS +
-						   " INTEGER;");
-			}
-			if (oldVersion < 15)
-			{
-				db.execSQL("ALTER TABLE " + TABLE_VPNPROFILE + " ADD " + KEY_IKE_PROPOSAL +
-						   " TEXT;");
-				db.execSQL("ALTER TABLE " + TABLE_VPNPROFILE + " ADD " + KEY_ESP_PROPOSAL +
-						   " TEXT;");
-			}
-			if (oldVersion < 16)
-			{	/* add a UUID to all entries that haven't one yet */
-				db.beginTransaction();
-				try
-				{
-					Cursor cursor = db.query(TABLE_VPNPROFILE, getColumns(16), KEY_UUID + " is NULL", null, null, null, null);
-					for (cursor.moveToFirst(); !cursor.isAfterLast(); cursor.moveToNext())
-					{
-						ContentValues values = new ContentValues();
-						values.put(KEY_UUID, UUID.randomUUID().toString());
-						db.update(TABLE_VPNPROFILE, values, KEY_ID + " = " + cursor.getLong(cursor.getColumnIndexOrThrow(KEY_ID)), null);
-					}
-					cursor.close();
-					db.setTransactionSuccessful();
-				}
-				finally
-				{
-					db.endTransaction();
-				}
-			}
-			if (oldVersion < 17)
-			{
-				db.execSQL("ALTER TABLE " + TABLE_VPNPROFILE + " ADD " + KEY_DNS_SERVERS +
-						   " TEXT;");
-			}
-		}
-
-		private void updateColumns(SQLiteDatabase db, int version)
-		{
-			db.beginTransaction();
-			try
-			{
-				db.execSQL("ALTER TABLE " + TABLE_VPNPROFILE + " RENAME TO tmp_" + TABLE_VPNPROFILE + ";");
-				db.execSQL(getDatabaseCreate(version));
-				StringBuilder insert = new StringBuilder("INSERT INTO " + TABLE_VPNPROFILE + " SELECT ");
-				SQLiteQueryBuilder.appendColumns(insert, getColumns(version));
-				db.execSQL(insert.append(" FROM tmp_" + TABLE_VPNPROFILE + ";").toString());
-				db.execSQL("DROP TABLE tmp_" + TABLE_VPNPROFILE + ";");
-				db.setTransactionSuccessful();
-			}
-			finally
-			{
-				db.endTransaction();
-			}
-		}
-	}
-
-	/**
-	 * Construct a new VPN profile data source. The context is used to
-	 * open/create the database.
-	 * @param context context used to access the database
-	 */
-	public VpnProfileDataSource(Context context)
-	{
-		this.mContext = context;
-	}
+	String KEY_ID = "_id";
+	String KEY_UUID = "_uuid";
+	String KEY_NAME = "name";
+	String KEY_GATEWAY = "gateway";
+	String KEY_VPN_TYPE = "vpn_type";
+	String KEY_USERNAME = "username";
+	String KEY_PASSWORD = "password";
+	String KEY_CERTIFICATE = "certificate";
+	String KEY_USER_CERTIFICATE = "user_certificate";
+	String KEY_MTU = "mtu";
+	String KEY_PORT = "port";
+	String KEY_SPLIT_TUNNELING = "split_tunneling";
+	String KEY_LOCAL_ID = "local_id";
+	String KEY_REMOTE_ID = "remote_id";
+	String KEY_EXCLUDED_SUBNETS = "excluded_subnets";
+	String KEY_INCLUDED_SUBNETS = "included_subnets";
+	String KEY_SELECTED_APPS = "selected_apps";
+	String KEY_SELECTED_APPS_LIST = "selected_apps_list";
+	String KEY_NAT_KEEPALIVE = "nat_keepalive";
+	String KEY_FLAGS = "flags";
+	String KEY_IKE_PROPOSAL = "ike_proposal";
+	String KEY_ESP_PROPOSAL = "esp_proposal";
+	String KEY_DNS_SERVERS = "dns_servers";
 
 	/**
 	 * Open the VPN profile data source. The database is automatically created
 	 * if it does not yet exist. If that fails an exception is thrown.
+	 *
 	 * @return itself (allows to chain initialization calls)
 	 * @throws SQLException if the database could not be opened or created
 	 */
-	public VpnProfileDataSource open() throws SQLException
-	{
-		if (mDbHelper == null)
-		{
-			mDbHelper = new DatabaseHelper(mContext);
-			mDatabase = mDbHelper.getWritableDatabase();
-		}
-		return this;
-	}
+	VpnProfileDataSource open() throws SQLException;
 
 	/**
 	 * Close the data source.
 	 */
-	public void close()
-	{
-		if (mDbHelper != null)
-		{
-			mDbHelper.close();
-			mDbHelper = null;
-		}
-	}
+	void close();
 
 	/**
 	 * Insert the given VPN profile into the database.  On success the Id of
@@ -318,83 +71,47 @@ public class VpnProfileDataSource
 	 * @param profile the profile to add
 	 * @return the added VPN profile or null, if failed
 	 */
-	public VpnProfile insertProfile(VpnProfile profile)
-	{
-		ContentValues values = ContentValuesFromVpnProfile(profile);
-		long insertId = mDatabase.insert(TABLE_VPNPROFILE, null, values);
-		if (insertId == -1)
-		{
-			return null;
-		}
-		profile.setId(insertId);
-		return profile;
-	}
+	VpnProfile insertProfile(VpnProfile profile);
 
 	/**
 	 * Updates the given VPN profile in the database.
+	 *
 	 * @param profile the profile to update
 	 * @return true if update succeeded, false otherwise
 	 */
-	public boolean updateVpnProfile(VpnProfile profile)
-	{
-		long id = profile.getId();
-		ContentValues values = ContentValuesFromVpnProfile(profile);
-		return mDatabase.update(TABLE_VPNPROFILE, values, KEY_ID + " = " + id, null) > 0;
-	}
+	boolean updateVpnProfile(VpnProfile profile);
 
 	/**
 	 * Delete the given VPN profile from the database.
+	 *
 	 * @param profile the profile to delete
 	 * @return true if deleted, false otherwise
 	 */
-	public boolean deleteVpnProfile(VpnProfile profile)
-	{
-		long id = profile.getId();
-		return mDatabase.delete(TABLE_VPNPROFILE, KEY_ID + " = " + id, null) > 0;
-	}
+	boolean deleteVpnProfile(VpnProfile profile);
 
 	/**
 	 * Get a single VPN profile from the database.
+	 *
 	 * @param id the ID of the VPN profile
 	 * @return the profile or null, if not found
 	 */
-	public VpnProfile getVpnProfile(long id)
-	{
-		VpnProfile profile = null;
-		Cursor cursor = mDatabase.query(TABLE_VPNPROFILE, ALL_COLUMNS,
-										KEY_ID + "=" + id, null, null, null, null);
-		if (cursor.moveToFirst())
-		{
-			profile = VpnProfileFromCursor(cursor);
-		}
-		cursor.close();
-		return profile;
-	}
+	VpnProfile getVpnProfile(long id);
 
 	/**
 	 * Get a single VPN profile from the database by its UUID.
+	 *
 	 * @param uuid the UUID of the VPN profile
 	 * @return the profile or null, if not found
 	 */
-	public VpnProfile getVpnProfile(UUID uuid)
-	{
-		VpnProfile profile = null;
-		Cursor cursor = mDatabase.query(TABLE_VPNPROFILE, ALL_COLUMNS,
-										KEY_UUID + "='" + uuid.toString() + "'", null, null, null, null);
-		if (cursor.moveToFirst())
-		{
-			profile = VpnProfileFromCursor(cursor);
-		}
-		cursor.close();
-		return profile;
-	}
+	VpnProfile getVpnProfile(UUID uuid);
 
 	/**
 	 * Get a single VPN profile from the database by its UUID as String.
+	 *
 	 * @param uuid the UUID of the VPN profile as String
 	 * @return the profile or null, if not found
 	 */
-	public VpnProfile getVpnProfile(String uuid)
+	default VpnProfile getVpnProfile(String uuid)
 	{
 		try
 		{
@@ -413,97 +130,8 @@ public class VpnProfileDataSource
 
 	/**
 	 * Get a list of all VPN profiles stored in the database.
+	 *
 	 * @return list of VPN profiles
 	 */
-	public List<VpnProfile> getAllVpnProfiles()
-	{
-		List<VpnProfile> vpnProfiles = new ArrayList<VpnProfile>();
-
-		Cursor cursor = mDatabase.query(TABLE_VPNPROFILE, ALL_COLUMNS, null, null, null, null, null);
-		cursor.moveToFirst();
-		while (!cursor.isAfterLast())
-		{
-			VpnProfile vpnProfile = VpnProfileFromCursor(cursor);
-			vpnProfiles.add(vpnProfile);
-			cursor.moveToNext();
-		}
-		cursor.close();
-		return vpnProfiles;
-	}
-
-	private VpnProfile VpnProfileFromCursor(Cursor cursor)
-	{
-		VpnProfile profile = new VpnProfile();
-		profile.setId(cursor.getLong(cursor.getColumnIndexOrThrow(KEY_ID)));
-		profile.setUUID(UUID.fromString(cursor.getString(cursor.getColumnIndexOrThrow(KEY_UUID))));
-		profile.setName(cursor.getString(cursor.getColumnIndexOrThrow(KEY_NAME)));
-		profile.setGateway(cursor.getString(cursor.getColumnIndexOrThrow(KEY_GATEWAY)));
-		profile.setVpnType(VpnType.fromIdentifier(cursor.getString(cursor.getColumnIndexOrThrow(KEY_VPN_TYPE))));
-		profile.setUsername(cursor.getString(cursor.getColumnIndexOrThrow(KEY_USERNAME)));
-		profile.setPassword(cursor.getString(cursor.getColumnIndexOrThrow(KEY_PASSWORD)));
-		profile.setCertificateAlias(cursor.getString(cursor.getColumnIndexOrThrow(KEY_CERTIFICATE)));
-		profile.setUserCertificateAlias(cursor.getString(cursor.getColumnIndexOrThrow(KEY_USER_CERTIFICATE)));
-		profile.setMTU(getInt(cursor, cursor.getColumnIndexOrThrow(KEY_MTU)));
-		profile.setPort(getInt(cursor, cursor.getColumnIndexOrThrow(KEY_PORT)));
-		profile.setSplitTunneling(getInt(cursor, cursor.getColumnIndexOrThrow(KEY_SPLIT_TUNNELING)));
-		profile.setLocalId(cursor.getString(cursor.getColumnIndexOrThrow(KEY_LOCAL_ID)));
-		profile.setRemoteId(cursor.getString(cursor.getColumnIndexOrThrow(KEY_REMOTE_ID)));
-		profile.setExcludedSubnets(cursor.getString(cursor.getColumnIndexOrThrow(KEY_EXCLUDED_SUBNETS)));
-		profile.setIncludedSubnets(cursor.getString(cursor.getColumnIndexOrThrow(KEY_INCLUDED_SUBNETS)));
-		profile.setSelectedAppsHandling(getInt(cursor, cursor.getColumnIndexOrThrow(KEY_SELECTED_APPS)));
-		profile.setSelectedApps(cursor.getString(cursor.getColumnIndexOrThrow(KEY_SELECTED_APPS_LIST)));
-		profile.setNATKeepAlive(getInt(cursor, cursor.getColumnIndexOrThrow(KEY_NAT_KEEPALIVE)));
-		profile.setFlags(getInt(cursor, cursor.getColumnIndexOrThrow(KEY_FLAGS)));
-		profile.setIkeProposal(cursor.getString(cursor.getColumnIndexOrThrow(KEY_IKE_PROPOSAL)));
-		profile.setEspProposal(cursor.getString(cursor.getColumnIndexOrThrow(KEY_ESP_PROPOSAL)));
-		profile.setDnsServers(cursor.getString(cursor.getColumnIndexOrThrow(KEY_DNS_SERVERS)));
-		return profile;
-	}
-
-	private ContentValues ContentValuesFromVpnProfile(VpnProfile profile)
-	{
-		ContentValues values = new ContentValues();
-		values.put(KEY_UUID, profile.getUUID().toString());
-		values.put(KEY_NAME, profile.getName());
-		values.put(KEY_GATEWAY, profile.getGateway());
-		values.put(KEY_VPN_TYPE, profile.getVpnType().getIdentifier());
-		values.put(KEY_USERNAME, profile.getUsername());
-		values.put(KEY_PASSWORD, profile.getPassword());
-		values.put(KEY_CERTIFICATE, profile.getCertificateAlias());
-		values.put(KEY_USER_CERTIFICATE, profile.getUserCertificateAlias());
-		values.put(KEY_MTU, profile.getMTU());
-		values.put(KEY_PORT, profile.getPort());
-		values.put(KEY_SPLIT_TUNNELING, profile.getSplitTunneling());
-		values.put(KEY_LOCAL_ID, profile.getLocalId());
-		values.put(KEY_REMOTE_ID, profile.getRemoteId());
-		values.put(KEY_EXCLUDED_SUBNETS, profile.getExcludedSubnets());
-		values.put(KEY_INCLUDED_SUBNETS, profile.getIncludedSubnets());
-		values.put(KEY_SELECTED_APPS, profile.getSelectedAppsHandling().getValue());
-		values.put(KEY_SELECTED_APPS_LIST, profile.getSelectedApps());
-		values.put(KEY_NAT_KEEPALIVE, profile.getNATKeepAlive());
-		values.put(KEY_FLAGS, profile.getFlags());
-		values.put(KEY_IKE_PROPOSAL, profile.getIkeProposal());
-		values.put(KEY_ESP_PROPOSAL, profile.getEspProposal());
-		values.put(KEY_DNS_SERVERS, profile.getDnsServers());
-		return values;
-	}
-
-	private Integer getInt(Cursor cursor, int columnIndex)
-	{
-		return cursor.isNull(columnIndex) ? null : cursor.getInt(columnIndex);
-	}
-
-	private static class DbColumn
-	{
-		public final String Name;
-		public final String Type;
-		public final Integer Since;
-
-		public DbColumn(String name, String type, Integer since)
-		{
-			Name = name;
-			Type = type;
-			Since = since;
-		}
-	}
+	List<VpnProfile> getAllVpnProfiles();
 }

src/frontends/android/app/src/main/java/org/strongswan/android/data/VpnProfileSource.java

@@ -0,0 +1,114 @@
+/*
+ * Copyright (C) 2023 Relution GmbH
+ *
+ * Copyright (C) secunet Security Networks AG
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation; either version 2 of the License, or (at your
+ * option) any later version.  See <http://www.fsf.org/copyleft/gpl.txt>.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+ * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * for more details.
+ */
+
+package org.strongswan.android.data;
+
+import android.content.Context;
+import android.database.SQLException;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.UUID;
+
+public class VpnProfileSource implements VpnProfileDataSource
+{
+	private final List<VpnProfileDataSource> dataSources = new ArrayList<>();
+	private final VpnProfileSqlDataSource vpnProfileSqlDataSource;
+
+	public VpnProfileSource(Context context)
+	{
+		vpnProfileSqlDataSource = new VpnProfileSqlDataSource(context);
+		dataSources.add(vpnProfileSqlDataSource);
+	}
+
+	@Override
+	public VpnProfileDataSource open() throws SQLException
+	{
+		for (final VpnProfileDataSource source : dataSources)
+		{
+			source.open();
+		}
+		return this;
+	}
+
+	@Override
+	public void close()
+	{
+		for (final VpnProfileDataSource source : dataSources)
+		{
+			source.close();
+		}
+	}
+
+	@Override
+	public VpnProfile insertProfile(VpnProfile profile)
+	{
+		return vpnProfileSqlDataSource.insertProfile(profile);
+	}
+
+	@Override
+	public boolean updateVpnProfile(VpnProfile profile)
+	{
+		return vpnProfileSqlDataSource.updateVpnProfile(profile);
+	}
+
+	@Override
+	public boolean deleteVpnProfile(VpnProfile profile)
+	{
+		return vpnProfileSqlDataSource.deleteVpnProfile(profile);
+	}
+
+	@Override
+	public VpnProfile getVpnProfile(long id)
+	{
+		for (final VpnProfileDataSource source : dataSources)
+		{
+			final VpnProfile profile = source.getVpnProfile(id);
+			if (profile != null)
+			{
+				return profile;
+			}
+		}
+		return null;
+	}
+
+	@Override
+	public VpnProfile getVpnProfile(UUID uuid)
+	{
+		for (final VpnProfileDataSource source : dataSources)
+		{
+			final VpnProfile profile = source.getVpnProfile(uuid);
+			if (profile != null)
+			{
+				return profile;
+			}
+		}
+		return null;
+	}
+
+	@Override
+	public List<VpnProfile> getAllVpnProfiles()
+	{
+		final List<VpnProfile> profiles = new ArrayList<>();
+
+		for (final VpnProfileDataSource source : dataSources)
+		{
+			profiles.addAll(source.getAllVpnProfiles());
+		}
+
+		return profiles;
+	}
+}

src/frontends/android/app/src/main/java/org/strongswan/android/data/VpnProfileSqlDataSource.java

@@ -0,0 +1,433 @@
+/*
+ * Copyright (C) 2012-2019 Tobias Brunner
+ * Copyright (C) 2012 Giuliano Grassi
+ * Copyright (C) 2012 Ralf Sager
+ *
+ * Copyright (C) secunet Security Networks AG
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation; either version 2 of the License, or (at your
+ * option) any later version.  See <http://www.fsf.org/copyleft/gpl.txt>.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+ * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * for more details.
+ */
+
+package org.strongswan.android.data;
+
+import android.content.ContentValues;
+import android.content.Context;
+import android.database.Cursor;
+import android.database.SQLException;
+import android.database.sqlite.SQLiteDatabase;
+import android.database.sqlite.SQLiteOpenHelper;
+import android.database.sqlite.SQLiteQueryBuilder;
+import android.util.Log;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.UUID;
+
+public class VpnProfileSqlDataSource implements VpnProfileDataSource
+{
+	private static final String TAG = VpnProfileSqlDataSource.class.getSimpleName();
+
+	private static final DbColumn[] COLUMNS = new VpnProfileSqlDataSource.DbColumn[]{
+		new VpnProfileSqlDataSource.DbColumn(KEY_ID, "INTEGER PRIMARY KEY AUTOINCREMENT", 1),
+		new VpnProfileSqlDataSource.DbColumn(KEY_UUID, "TEXT UNIQUE", 9),
+		new VpnProfileSqlDataSource.DbColumn(KEY_NAME, "TEXT NOT NULL", 1),
+		new VpnProfileSqlDataSource.DbColumn(KEY_GATEWAY, "TEXT NOT NULL", 1),
+		new VpnProfileSqlDataSource.DbColumn(KEY_VPN_TYPE, "TEXT NOT NULL", 3),
+		new VpnProfileSqlDataSource.DbColumn(KEY_USERNAME, "TEXT", 1),
+		new VpnProfileSqlDataSource.DbColumn(KEY_PASSWORD, "TEXT", 1),
+		new VpnProfileSqlDataSource.DbColumn(KEY_CERTIFICATE, "TEXT", 1),
+		new VpnProfileSqlDataSource.DbColumn(KEY_USER_CERTIFICATE, "TEXT", 2),
+		new VpnProfileSqlDataSource.DbColumn(KEY_MTU, "INTEGER", 5),
+		new VpnProfileSqlDataSource.DbColumn(KEY_PORT, "INTEGER", 5),
+		new VpnProfileSqlDataSource.DbColumn(KEY_SPLIT_TUNNELING, "INTEGER", 7),
+		new VpnProfileSqlDataSource.DbColumn(KEY_LOCAL_ID, "TEXT", 8),
+		new VpnProfileSqlDataSource.DbColumn(KEY_REMOTE_ID, "TEXT", 8),
+		new VpnProfileSqlDataSource.DbColumn(KEY_EXCLUDED_SUBNETS, "TEXT", 10),
+		new VpnProfileSqlDataSource.DbColumn(KEY_INCLUDED_SUBNETS, "TEXT", 11),
+		new VpnProfileSqlDataSource.DbColumn(KEY_SELECTED_APPS, "INTEGER", 12),
+		new VpnProfileSqlDataSource.DbColumn(KEY_SELECTED_APPS_LIST, "TEXT", 12),
+		new VpnProfileSqlDataSource.DbColumn(KEY_NAT_KEEPALIVE, "INTEGER", 13),
+		new VpnProfileSqlDataSource.DbColumn(KEY_FLAGS, "INTEGER", 14),
+		new VpnProfileSqlDataSource.DbColumn(KEY_IKE_PROPOSAL, "TEXT", 15),
+		new VpnProfileSqlDataSource.DbColumn(KEY_ESP_PROPOSAL, "TEXT", 15),
+		new VpnProfileSqlDataSource.DbColumn(KEY_DNS_SERVERS, "TEXT", 17),
+	};
+
+	private DatabaseHelper mDbHelper;
+	private SQLiteDatabase mDatabase;
+	private final Context mContext;
+
+	private static final String DATABASE_NAME = "strongswan.db";
+	private static final String TABLE_VPNPROFILE = "vpnprofile";
+
+	private static final int DATABASE_VERSION = 17;
+
+	private static final String[] ALL_COLUMNS = getColumns(DATABASE_VERSION);
+
+	private static String getDatabaseCreate(int version)
+	{
+		boolean first = true;
+		StringBuilder create = new StringBuilder("CREATE TABLE ");
+		create.append(TABLE_VPNPROFILE);
+		create.append(" (");
+		for (DbColumn column : COLUMNS)
+		{
+			if (column.Since <= version)
+			{
+				if (!first)
+				{
+					create.append(",");
+				}
+				first = false;
+				create.append(column.Name);
+				create.append(" ");
+				create.append(column.Type);
+			}
+		}
+		create.append(");");
+		return create.toString();
+	}
+
+	private static String[] getColumns(int version)
+	{
+		ArrayList<String> columns = new ArrayList<>();
+		for (DbColumn column : COLUMNS)
+		{
+			if (column.Since <= version)
+			{
+				columns.add(column.Name);
+			}
+		}
+		return columns.toArray(new String[0]);
+	}
+
+	private static class DatabaseHelper extends SQLiteOpenHelper
+	{
+		public DatabaseHelper(Context context)
+		{
+			super(context, DATABASE_NAME, null, DATABASE_VERSION);
+		}
+
+		@Override
+		public void onCreate(SQLiteDatabase database)
+		{
+			database.execSQL(getDatabaseCreate(DATABASE_VERSION));
+		}
+
+		@Override
+		public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion)
+		{
+			Log.w(TAG, "Upgrading database from version " + oldVersion +
+				  " to " + newVersion);
+			if (oldVersion < 2)
+			{
+				db.execSQL("ALTER TABLE " + TABLE_VPNPROFILE + " ADD " + KEY_USER_CERTIFICATE +
+						   " TEXT;");
+			}
+			if (oldVersion < 3)
+			{
+				db.execSQL("ALTER TABLE " + TABLE_VPNPROFILE + " ADD " + KEY_VPN_TYPE +
+						   " TEXT DEFAULT '';");
+			}
+			if (oldVersion < 4)
+			{	/* remove NOT NULL constraint from username column */
+				updateColumns(db, 4);
+			}
+			if (oldVersion < 5)
+			{
+				db.execSQL("ALTER TABLE " + TABLE_VPNPROFILE + " ADD " + KEY_MTU +
+						   " INTEGER;");
+			}
+			if (oldVersion < 6)
+			{
+				db.execSQL("ALTER TABLE " + TABLE_VPNPROFILE + " ADD " + KEY_PORT +
+						   " INTEGER;");
+			}
+			if (oldVersion < 7)
+			{
+				db.execSQL("ALTER TABLE " + TABLE_VPNPROFILE + " ADD " + KEY_SPLIT_TUNNELING +
+						   " INTEGER;");
+			}
+			if (oldVersion < 8)
+			{
+				db.execSQL("ALTER TABLE " + TABLE_VPNPROFILE + " ADD " + KEY_LOCAL_ID +
+						   " TEXT;");
+				db.execSQL("ALTER TABLE " + TABLE_VPNPROFILE + " ADD " + KEY_REMOTE_ID +
+						   " TEXT;");
+			}
+			if (oldVersion < 9)
+			{
+				db.execSQL("ALTER TABLE " + TABLE_VPNPROFILE + " ADD " + KEY_UUID +
+						   " TEXT;");
+				updateColumns(db, 9);
+			}
+			if (oldVersion < 10)
+			{
+				db.execSQL("ALTER TABLE " + TABLE_VPNPROFILE + " ADD " + KEY_EXCLUDED_SUBNETS +
+						   " TEXT;");
+			}
+			if (oldVersion < 11)
+			{
+				db.execSQL("ALTER TABLE " + TABLE_VPNPROFILE + " ADD " + KEY_INCLUDED_SUBNETS +
+						   " TEXT;");
+			}
+			if (oldVersion < 12)
+			{
+				db.execSQL("ALTER TABLE " + TABLE_VPNPROFILE + " ADD " + KEY_SELECTED_APPS +
+						   " INTEGER;");
+				db.execSQL("ALTER TABLE " + TABLE_VPNPROFILE + " ADD " + KEY_SELECTED_APPS_LIST +
+						   " TEXT;");
+			}
+			if (oldVersion < 13)
+			{
+				db.execSQL("ALTER TABLE " + TABLE_VPNPROFILE + " ADD " + KEY_NAT_KEEPALIVE +
+						   " INTEGER;");
+			}
+			if (oldVersion < 14)
+			{
+				db.execSQL("ALTER TABLE " + TABLE_VPNPROFILE + " ADD " + KEY_FLAGS +
+						   " INTEGER;");
+			}
+			if (oldVersion < 15)
+			{
+				db.execSQL("ALTER TABLE " + TABLE_VPNPROFILE + " ADD " + KEY_IKE_PROPOSAL +
+						   " TEXT;");
+				db.execSQL("ALTER TABLE " + TABLE_VPNPROFILE + " ADD " + KEY_ESP_PROPOSAL +
+						   " TEXT;");
+			}
+			if (oldVersion < 16)
+			{	/* add a UUID to all entries that haven't one yet */
+				db.beginTransaction();
+				try
+				{
+					Cursor cursor = db.query(TABLE_VPNPROFILE, getColumns(16), KEY_UUID + " is NULL", null, null, null, null);
+					for (cursor.moveToFirst(); !cursor.isAfterLast(); cursor.moveToNext())
+					{
+						ContentValues values = new ContentValues();
+						values.put(KEY_UUID, UUID.randomUUID().toString());
+						db.update(TABLE_VPNPROFILE, values, KEY_ID + " = " + cursor.getLong(cursor.getColumnIndexOrThrow(KEY_ID)), null);
+					}
+					cursor.close();
+					db.setTransactionSuccessful();
+				}
+				finally
+				{
+					db.endTransaction();
+				}
+			}
+			if (oldVersion < 17)
+			{
+				db.execSQL("ALTER TABLE " + TABLE_VPNPROFILE + " ADD " + KEY_DNS_SERVERS +
+						   " TEXT;");
+			}
+		}
+
+		private void updateColumns(SQLiteDatabase db, int version)
+		{
+			db.beginTransaction();
+			try
+			{
+				db.execSQL("ALTER TABLE " + TABLE_VPNPROFILE + " RENAME TO tmp_" + TABLE_VPNPROFILE + ";");
+				db.execSQL(getDatabaseCreate(version));
+				StringBuilder insert = new StringBuilder("INSERT INTO " + TABLE_VPNPROFILE + " SELECT ");
+				SQLiteQueryBuilder.appendColumns(insert, getColumns(version));
+				db.execSQL(insert.append(" FROM tmp_" + TABLE_VPNPROFILE + ";").toString());
+				db.execSQL("DROP TABLE tmp_" + TABLE_VPNPROFILE + ";");
+				db.setTransactionSuccessful();
+			}
+			finally
+			{
+				db.endTransaction();
+			}
+		}
+	}
+
+	/**
+	 * Construct a new VPN profile data source. The context is used to
+	 * open/create the database.
+	 *
+	 * @param context context used to access the database
+	 */
+	public VpnProfileSqlDataSource(Context context)
+	{
+		this.mContext = context;
+	}
+
+	@Override
+	public VpnProfileDataSource open() throws SQLException
+	{
+		if (mDbHelper == null)
+		{
+			mDbHelper = new DatabaseHelper(mContext);
+			mDatabase = mDbHelper.getWritableDatabase();
+		}
+		return this;
+	}
+
+	@Override
+	public void close()
+	{
+		if (mDbHelper != null)
+		{
+			mDbHelper.close();
+			mDbHelper = null;
+		}
+	}
+
+	@Override
+	public VpnProfile insertProfile(VpnProfile profile)
+	{
+		ContentValues values = ContentValuesFromVpnProfile(profile);
+		long insertId = mDatabase.insert(TABLE_VPNPROFILE, null, values);
+		if (insertId == -1)
+		{
+			return null;
+		}
+		profile.setId(insertId);
+		return profile;
+	}
+
+	@Override
+	public boolean updateVpnProfile(VpnProfile profile)
+	{
+		long id = profile.getId();
+		ContentValues values = ContentValuesFromVpnProfile(profile);
+		return mDatabase.update(TABLE_VPNPROFILE, values, KEY_ID + " = " + id, null) > 0;
+	}
+
+	@Override
+	public boolean deleteVpnProfile(VpnProfile profile)
+	{
+		long id = profile.getId();
+		return mDatabase.delete(TABLE_VPNPROFILE, KEY_ID + " = " + id, null) > 0;
+	}
+
+	@Override
+	public VpnProfile getVpnProfile(long id)
+	{
+		VpnProfile profile = null;
+		Cursor cursor = mDatabase.query(TABLE_VPNPROFILE, ALL_COLUMNS,
+										KEY_ID + "=" + id, null, null, null, null);
+		if (cursor.moveToFirst())
+		{
+			profile = VpnProfileFromCursor(cursor);
+		}
+		cursor.close();
+		return profile;
+	}
+
+	@Override
+	public VpnProfile getVpnProfile(UUID uuid)
+	{
+		VpnProfile profile = null;
+		Cursor cursor = mDatabase.query(TABLE_VPNPROFILE, ALL_COLUMNS,
+										KEY_UUID + "='" + uuid.toString() + "'", null, null, null, null);
+		if (cursor.moveToFirst())
+		{
+			profile = VpnProfileFromCursor(cursor);
+		}
+		cursor.close();
+		return profile;
+	}
+
+	@Override
+	public List<VpnProfile> getAllVpnProfiles()
+	{
+		List<VpnProfile> vpnProfiles = new ArrayList<VpnProfile>();
+
+		Cursor cursor = mDatabase.query(TABLE_VPNPROFILE, ALL_COLUMNS, null, null, null, null, null);
+		cursor.moveToFirst();
+		while (!cursor.isAfterLast())
+		{
+			VpnProfile vpnProfile = VpnProfileFromCursor(cursor);
+			vpnProfiles.add(vpnProfile);
+			cursor.moveToNext();
+		}
+		cursor.close();
+		return vpnProfiles;
+	}
+
+	private VpnProfile VpnProfileFromCursor(Cursor cursor)
+	{
+		VpnProfile profile = new VpnProfile();
+		profile.setId(cursor.getLong(cursor.getColumnIndexOrThrow(KEY_ID)));
+		profile.setUUID(UUID.fromString(cursor.getString(cursor.getColumnIndexOrThrow(KEY_UUID))));
+		profile.setName(cursor.getString(cursor.getColumnIndexOrThrow(KEY_NAME)));
+		profile.setGateway(cursor.getString(cursor.getColumnIndexOrThrow(KEY_GATEWAY)));
+		profile.setVpnType(VpnType.fromIdentifier(cursor.getString(cursor.getColumnIndexOrThrow(KEY_VPN_TYPE))));
+		profile.setUsername(cursor.getString(cursor.getColumnIndexOrThrow(KEY_USERNAME)));
+		profile.setPassword(cursor.getString(cursor.getColumnIndexOrThrow(KEY_PASSWORD)));
+		profile.setCertificateAlias(cursor.getString(cursor.getColumnIndexOrThrow(KEY_CERTIFICATE)));
+		profile.setUserCertificateAlias(cursor.getString(cursor.getColumnIndexOrThrow(KEY_USER_CERTIFICATE)));
+		profile.setMTU(getInt(cursor, cursor.getColumnIndexOrThrow(KEY_MTU)));
+		profile.setPort(getInt(cursor, cursor.getColumnIndexOrThrow(KEY_PORT)));
+		profile.setSplitTunneling(getInt(cursor, cursor.getColumnIndexOrThrow(KEY_SPLIT_TUNNELING)));
+		profile.setLocalId(cursor.getString(cursor.getColumnIndexOrThrow(KEY_LOCAL_ID)));
+		profile.setRemoteId(cursor.getString(cursor.getColumnIndexOrThrow(KEY_REMOTE_ID)));
+		profile.setExcludedSubnets(cursor.getString(cursor.getColumnIndexOrThrow(KEY_EXCLUDED_SUBNETS)));
+		profile.setIncludedSubnets(cursor.getString(cursor.getColumnIndexOrThrow(KEY_INCLUDED_SUBNETS)));
+		profile.setSelectedAppsHandling(getInt(cursor, cursor.getColumnIndexOrThrow(KEY_SELECTED_APPS)));
+		profile.setSelectedApps(cursor.getString(cursor.getColumnIndexOrThrow(KEY_SELECTED_APPS_LIST)));
+		profile.setNATKeepAlive(getInt(cursor, cursor.getColumnIndexOrThrow(KEY_NAT_KEEPALIVE)));
+		profile.setFlags(getInt(cursor, cursor.getColumnIndexOrThrow(KEY_FLAGS)));
+		profile.setIkeProposal(cursor.getString(cursor.getColumnIndexOrThrow(KEY_IKE_PROPOSAL)));
+		profile.setEspProposal(cursor.getString(cursor.getColumnIndexOrThrow(KEY_ESP_PROPOSAL)));
+		profile.setDnsServers(cursor.getString(cursor.getColumnIndexOrThrow(KEY_DNS_SERVERS)));
+		return profile;
+	}
+
+	private ContentValues ContentValuesFromVpnProfile(VpnProfile profile)
+	{
+		ContentValues values = new ContentValues();
+		values.put(KEY_UUID, profile.getUUID().toString());
+		values.put(KEY_NAME, profile.getName());
+		values.put(KEY_GATEWAY, profile.getGateway());
+		values.put(KEY_VPN_TYPE, profile.getVpnType().getIdentifier());
+		values.put(KEY_USERNAME, profile.getUsername());
+		values.put(KEY_PASSWORD, profile.getPassword());
+		values.put(KEY_CERTIFICATE, profile.getCertificateAlias());
+		values.put(KEY_USER_CERTIFICATE, profile.getUserCertificateAlias());
+		values.put(KEY_MTU, profile.getMTU());
+		values.put(KEY_PORT, profile.getPort());
+		values.put(KEY_SPLIT_TUNNELING, profile.getSplitTunneling());
+		values.put(KEY_LOCAL_ID, profile.getLocalId());
+		values.put(KEY_REMOTE_ID, profile.getRemoteId());
+		values.put(KEY_EXCLUDED_SUBNETS, profile.getExcludedSubnets());
+		values.put(KEY_INCLUDED_SUBNETS, profile.getIncludedSubnets());
+		values.put(KEY_SELECTED_APPS, profile.getSelectedAppsHandling().getValue());
+		values.put(KEY_SELECTED_APPS_LIST, profile.getSelectedApps());
+		values.put(KEY_NAT_KEEPALIVE, profile.getNATKeepAlive());
+		values.put(KEY_FLAGS, profile.getFlags());
+		values.put(KEY_IKE_PROPOSAL, profile.getIkeProposal());
+		values.put(KEY_ESP_PROPOSAL, profile.getEspProposal());
+		values.put(KEY_DNS_SERVERS, profile.getDnsServers());
+		return values;
+	}
+
+	private Integer getInt(Cursor cursor, int columnIndex)
+	{
+		return cursor.isNull(columnIndex) ? null : cursor.getInt(columnIndex);
+	}
+
+	private static class DbColumn
+	{
+		public final String Name;
+		public final String Type;
+		public final Integer Since;
+
+		public DbColumn(String name, String type, Integer since)
+		{
+			Name = name;
+			Type = type;
+			Since = since;
+		}
+	}
+}

src/frontends/android/app/src/main/java/org/strongswan/android/logic/CharonVpnService.java

@@ -45,6 +45,7 @@ import org.strongswan.android.R;
 import org.strongswan.android.data.VpnProfile;
 import org.strongswan.android.data.VpnProfile.SelectedAppsHandling;
 import org.strongswan.android.data.VpnProfileDataSource;
+import org.strongswan.android.data.VpnProfileSource;
 import org.strongswan.android.data.VpnType.VpnTypeFeature;
 import org.strongswan.android.logic.VpnStateService.ErrorState;
 import org.strongswan.android.logic.VpnStateService.State;
@@ -196,7 +197,7 @@ public class CharonVpnService extends VpnService implements Runnable, VpnStateSe
 		/* handler used to do changes in the main UI thread */
 		mHandler = new Handler(getMainLooper());
 
-		mDataSource = new VpnProfileDataSource(this);
+		mDataSource = new VpnProfileSource(this);
 		mDataSource.open();
 		/* use a separate thread as main thread for charon */
 		mConnectionHandler = new Thread(this);

src/frontends/android/app/src/main/java/org/strongswan/android/ui/SettingsFragment.java

@@ -16,6 +16,9 @@
 
 package org.strongswan.android.ui;
 
+import static org.strongswan.android.utils.Constants.PREF_DEFAULT_VPN_PROFILE;
+import static org.strongswan.android.utils.Constants.PREF_DEFAULT_VPN_PROFILE_MRU;
+
 import android.content.SharedPreferences;
 import android.os.Build;
 import android.os.Bundle;
@@ -23,6 +26,7 @@ import android.os.Bundle;
 import org.strongswan.android.R;
 import org.strongswan.android.data.VpnProfile;
 import org.strongswan.android.data.VpnProfileDataSource;
+import org.strongswan.android.data.VpnProfileSource;
 
 import java.util.ArrayList;
 import java.util.Collections;
@@ -34,9 +38,6 @@ import androidx.preference.Preference;
 import androidx.preference.PreferenceFragmentCompat;
 import androidx.preference.PreferenceManager;
 
-import static org.strongswan.android.utils.Constants.PREF_DEFAULT_VPN_PROFILE;
-import static org.strongswan.android.utils.Constants.PREF_DEFAULT_VPN_PROFILE_MRU;
-
 public class SettingsFragment extends PreferenceFragmentCompat implements Preference.OnPreferenceChangeListener
 {
 	private ListPreference mDefaultVPNProfile;
@@ -46,7 +47,7 @@ public class SettingsFragment extends PreferenceFragmentCompat implements Prefer
 	{
 		setPreferencesFromResource(R.xml.settings, s);
 
-		mDefaultVPNProfile = (ListPreference)findPreference(PREF_DEFAULT_VPN_PROFILE);
+		mDefaultVPNProfile = findPreference(PREF_DEFAULT_VPN_PROFILE);
 		mDefaultVPNProfile.setOnPreferenceChangeListener(this);
 		if (Build.VERSION.SDK_INT < Build.VERSION_CODES.N)
 		{
@@ -59,11 +60,12 @@ public class SettingsFragment extends PreferenceFragmentCompat implements Prefer
 	{
 		super.onResume();
 
-		VpnProfileDataSource profiles = new VpnProfileDataSource(getActivity());
+		VpnProfileDataSource profiles = new VpnProfileSource(getActivity());
 		profiles.open();
 
 		List<VpnProfile> all = profiles.getAllVpnProfiles();
-		Collections.sort(all, new Comparator<VpnProfile>() {
+		Collections.sort(all, new Comparator<VpnProfile>()
+		{
 			@Override
 			public int compare(VpnProfile lhs, VpnProfile rhs)
 			{
@@ -111,7 +113,7 @@ public class SettingsFragment extends PreferenceFragmentCompat implements Prefer
 
 	private void setCurrentProfileName(String uuid)
 	{
-		VpnProfileDataSource profiles = new VpnProfileDataSource(getActivity());
+		VpnProfileDataSource profiles = new VpnProfileSource(getActivity());
 		profiles.open();
 
 		if (!uuid.equals(PREF_DEFAULT_VPN_PROFILE_MRU))

src/frontends/android/app/src/main/java/org/strongswan/android/ui/VpnProfileControlActivity.java

@@ -42,12 +42,12 @@ import android.widget.Toast;
 import org.strongswan.android.R;
 import org.strongswan.android.data.VpnProfile;
 import org.strongswan.android.data.VpnProfileDataSource;
+import org.strongswan.android.data.VpnProfileSource;
 import org.strongswan.android.data.VpnType.VpnTypeFeature;
 import org.strongswan.android.logic.VpnStateService;
 import org.strongswan.android.logic.VpnStateService.State;
 import org.strongswan.android.utils.Constants;
 
-import androidx.activity.result.ActivityResultCallback;
 import androidx.activity.result.ActivityResultLauncher;
 import androidx.activity.result.contract.ActivityResultContracts;
 import androidx.annotation.NonNull;
@@ -257,6 +257,7 @@ public class VpnProfileControlActivity extends AppCompatActivity
 	/**
 	 * Check if we have permission to display notifications to the user, if necessary,
 	 * ask the user to allow this.
+	 *
 	 * @return true if profile can be initiated immediately
 	 */
 	private boolean checkNotificationPermission()
@@ -274,6 +275,7 @@ public class VpnProfileControlActivity extends AppCompatActivity
 	/**
 	 * Check if we are on the system's power whitelist, if necessary, or ask the user
 	 * to add us.
+	 *
 	 * @return true if profile can be initiated immediately
 	 */
 	private boolean checkPowerWhitelist()
@@ -373,7 +375,7 @@ public class VpnProfileControlActivity extends AppCompatActivity
 	{
 		VpnProfile profile = null;
 
-		VpnProfileDataSource dataSource = new VpnProfileDataSource(this);
+		VpnProfileDataSource dataSource = new VpnProfileSource(this);
 		dataSource.open();
 		String profileUUID = intent.getStringExtra(EXTRA_VPN_PROFILE_ID);
 		if (profileUUID != null)
@@ -415,7 +417,7 @@ public class VpnProfileControlActivity extends AppCompatActivity
 		String profileUUID = intent.getStringExtra(EXTRA_VPN_PROFILE_ID);
 		if (profileUUID != null)
 		{
-			VpnProfileDataSource dataSource = new VpnProfileDataSource(this);
+			VpnProfileDataSource dataSource = new VpnProfileSource(this);
 			dataSource.open();
 			profile = dataSource.getVpnProfile(profileUUID);
 			dataSource.close();
@@ -583,9 +585,9 @@ public class VpnProfileControlActivity extends AppCompatActivity
 			final Bundle profileInfo = getArguments();
 			LayoutInflater inflater = getActivity().getLayoutInflater();
 			View view = inflater.inflate(R.layout.login_dialog, null);
-			EditText username = (EditText)view.findViewById(R.id.username);
+			EditText username = view.findViewById(R.id.username);
 			username.setText(profileInfo.getString(VpnProfileDataSource.KEY_USERNAME));
-			final EditText password = (EditText)view.findViewById(R.id.password);
+			final EditText password = view.findViewById(R.id.password);
 
 			AlertDialog.Builder adb = new AlertDialog.Builder(getActivity());
 			adb.setView(view);

src/frontends/android/app/src/main/java/org/strongswan/android/ui/VpnProfileDetailActivity.java

@@ -56,6 +56,7 @@ import org.strongswan.android.R;
 import org.strongswan.android.data.VpnProfile;
 import org.strongswan.android.data.VpnProfile.SelectedAppsHandling;
 import org.strongswan.android.data.VpnProfileDataSource;
+import org.strongswan.android.data.VpnProfileSource;
 import org.strongswan.android.data.VpnType;
 import org.strongswan.android.data.VpnType.VpnTypeFeature;
 import org.strongswan.android.logic.StrongSwanApplication;
@@ -188,7 +189,7 @@ public class VpnProfileDetailActivity extends AppCompatActivity
 		/* the title is set when we load the profile, if any */
 		getSupportActionBar().setDisplayHomeAsUpEnabled(true);
 
-		mDataSource = new VpnProfileDataSource(this);
+		mDataSource = new VpnProfileSource(this);
 		mDataSource.open();
 
 		setContentView(R.layout.profile_detail_view);

src/frontends/android/app/src/main/java/org/strongswan/android/ui/VpnProfileImportActivity.java

@@ -45,6 +45,7 @@ import org.strongswan.android.R;
 import org.strongswan.android.data.VpnProfile;
 import org.strongswan.android.data.VpnProfile.SelectedAppsHandling;
 import org.strongswan.android.data.VpnProfileDataSource;
+import org.strongswan.android.data.VpnProfileSource;
 import org.strongswan.android.data.VpnType;
 import org.strongswan.android.data.VpnType.VpnTypeFeature;
 import org.strongswan.android.logic.TrustedCertificateManager;
@@ -184,7 +185,7 @@ public class VpnProfileImportActivity extends AppCompatActivity
 		getSupportActionBar().setHomeAsUpIndicator(R.drawable.ic_close_white_24dp);
 		getSupportActionBar().setDisplayHomeAsUpEnabled(true);
 
-		mDataSource = new VpnProfileDataSource(this);
+		mDataSource = new VpnProfileSource(this);
 		mDataSource.open();
 
 		setContentView(R.layout.profile_import_view);

src/frontends/android/app/src/main/java/org/strongswan/android/ui/VpnProfileListFragment.java

@@ -41,6 +41,7 @@ import android.widget.Toast;
 import org.strongswan.android.R;
 import org.strongswan.android.data.VpnProfile;
 import org.strongswan.android.data.VpnProfileDataSource;
+import org.strongswan.android.data.VpnProfileSource;
 import org.strongswan.android.ui.adapter.VpnProfileAdapter;
 import org.strongswan.android.utils.Constants;
 
@@ -65,12 +66,14 @@ public class VpnProfileListFragment extends Fragment
 	private HashSet<Integer> mSelected;
 	private boolean mReadOnly;
 
-	private BroadcastReceiver mProfilesChanged = new BroadcastReceiver()
+	private final BroadcastReceiver mProfilesChanged = new BroadcastReceiver()
 	{
 		@Override
 		public void onReceive(Context context, Intent intent)
 		{
-			long id, ids[];
+			long id;
+			long[] ids;
+
 			if ((id = intent.getLongExtra(Constants.VPN_PROFILES_SINGLE, 0)) > 0)
 			{
 				VpnProfile profile = mDataSource.getVpnProfile(id);
@@ -104,7 +107,8 @@ public class VpnProfileListFragment extends Fragment
 	/**
 	 * The activity containing this fragment should implement this interface
 	 */
-	public interface OnVpnProfileSelectedListener {
+	public interface OnVpnProfileSelectedListener
+	{
 		void onVpnProfileSelected(VpnProfile profile);
 	}
 
@@ -159,7 +163,7 @@ public class VpnProfileListFragment extends Fragment
 			mSelected = selected != null ? new HashSet<>(selected) : new HashSet<>();
 		}
 
-		mDataSource = new VpnProfileDataSource(this.getActivity());
+		mDataSource = new VpnProfileSource(this.getActivity());
 		mDataSource.open();
 
 		/* cached list of profiles used as backend for the ListView */
@@ -206,19 +210,18 @@ public class VpnProfileListFragment extends Fragment
 	@Override
 	public boolean onOptionsItemSelected(MenuItem item)
 	{
-		switch (item.getItemId())
+		if (item.getItemId() == R.id.add_profile)
 		{
-			case R.id.add_profile:
-				Intent connectionIntent = new Intent(getActivity(),
-													 VpnProfileDetailActivity.class);
-				startActivity(connectionIntent);
-				return true;
-			default:
-				return super.onOptionsItemSelected(item);
+			Intent connectionIntent = new Intent(getActivity(),
+												 VpnProfileDetailActivity.class);
+			startActivity(connectionIntent);
+			return true;
 		}
+		return super.onOptionsItemSelected(item);
 	}
 
-	private final OnItemClickListener mVpnProfileClicked = new OnItemClickListener() {
+	private final OnItemClickListener mVpnProfileClicked = new OnItemClickListener()
+	{
 		@Override
 		public void onItemClick(AdapterView<?> a, View v, int position, long id)
 		{
@@ -229,7 +232,8 @@ public class VpnProfileListFragment extends Fragment
 		}
 	};
 
-	private final MultiChoiceModeListener mVpnProfileSelected = new MultiChoiceModeListener() {
+	private final MultiChoiceModeListener mVpnProfileSelected = new MultiChoiceModeListener()
+	{
 		private MenuItem mEditProfile;
 		private MenuItem mCopyProfile;
 
@@ -297,7 +301,7 @@ public class VpnProfileListFragment extends Fragment
 					{
 						profiles.add((VpnProfile)mListView.getItemAtPosition(position));
 					}
-					long ids[] = new long[profiles.size()];
+					long[] ids = new long[profiles.size()];
 					for (int i = 0; i < profiles.size(); i++)
 					{
 						VpnProfile profile = profiles.get(i);

src/frontends/android/app/src/main/java/org/strongswan/android/ui/VpnTileService.java

@@ -32,6 +32,7 @@ import android.service.quicksettings.TileService;
 import org.strongswan.android.R;
 import org.strongswan.android.data.VpnProfile;
 import org.strongswan.android.data.VpnProfileDataSource;
+import org.strongswan.android.data.VpnProfileSource;
 import org.strongswan.android.data.VpnType;
 import org.strongswan.android.logic.VpnStateService;
 import org.strongswan.android.utils.Constants;
@@ -73,7 +74,7 @@ public class VpnTileService extends TileService implements VpnStateService.VpnSt
 		context.bindService(new Intent(context, VpnStateService.class),
 							mServiceConnection, Service.BIND_AUTO_CREATE);
 
-		mDataSource = new VpnProfileDataSource(this);
+		mDataSource = new VpnProfileSource(this);
 		mDataSource.open();
 	}