gist from modified smsmmsdatabasehelper

databasehelper.java

  private SecureComMmsSmsDatabaseHelper(Context context) {
		super(context, DATABASE_NAME, null, DATABASE_VERSION);
		mContext = context;
		initializePassword();
	}
	
	public void initializeWithPassword(String password){
		if (mPassword == null) {
			mPassword = new char[128];
		}
		Arrays.fill(mPassword, ' ');
		
		if(!TextUtils.isEmpty(password)){
			char[] charPass = password.toCharArray();
			for (int i = 0; i < charPass.length; i++) {
				mPassword[i] = charPass[i];
			}
			Arrays.fill(charPass, ' ');
		}	
	}
	
	private void initializePassword(){
//		keyReceiver = new NewKeyReceiver();
//		IntentFilter filter = new IntentFilter(KeyCachingService.NEW_PASSWORD_EVENT);
//		LocalBroadcastManager.getInstance(mContext).registerReceiver(keyReceiver, filter);
		
		Intent bindInent = new Intent(mContext, KeyCachingService.class);
		mContext.bindService(bindInent, serviceConnection, Context.BIND_AUTO_CREATE);
		
		
	}
	
	private ServiceConnection serviceConnection = new ServiceConnection(){

		@Override
		public void onServiceConnected(ComponentName componentName, IBinder service) {
			KeyCachingService keyCachingService = ((KeyCachingService.KeyCachingBinder)service).getService();
			String password = keyCachingService.getPassword();
			
			initializeWithPassword(password);
			mContext.unbindService(this);
			
		}

		@Override
		public void onServiceDisconnected(ComponentName arg0) {
			// TODO Auto-generated method stub
			
		}
		
	};
	
//	private class NewKeyReceiver extends BroadcastReceiver {
//		@Override
//		public void onReceive(Context context, Intent intent){
//			initializeWithPassword(intent.getStringExtra("password"));
//		}
//	}

	private String getPassword() {
		if (!TextUtils.isEmpty(mPassword.toString())) {
			return new String(mPassword).trim();
		} else {
			return null;
		}
	}

	
	public boolean hasPassword() {
		return mPassword != null && mPassword[0] != ' ';
	}

	public boolean rekey(String oldPassword, String newPassword) {
		if (oldPassword.equals(getPassword())) {
			mInstance.getWritableDatabase().execSQL("PRAGMA rekey = '" + newPassword + "'");
			initializeWithPassword(newPassword);
			System.gc();
			return true;
		} else {
			System.gc();
			return false;
		}
	}
	

	/**
	 * Return a singleton helper for the combined MMS and SMS database. TODO
	 * remove public package
	 */
	public static synchronized SecureComMmsSmsDatabaseHelper getInstance(Context context) { 
		if (mInstance == null) {
			mInstance = new SecureComMmsSmsDatabaseHelper(context);
			
		}
		return mInstance;
	}

	public SQLiteDatabase getWritableDatabase() {
		return mInstance.getWritableDatabase(getPassword());
	}

	public SQLiteDatabase getReadableDatabase() {
		return mInstance.getReadableDatabase(getPassword());
	}

provider.java

 
  @Override
	public boolean onCreate() {
		SQLiteDatabase.loadLibs(getContext());
		mUseStrictPhoneNumberComparation = getContext().getResources().getBoolean(R.bool.config_use_strict_phone_number_comparation);
		mOpenHelper = SecureComMmsSmsDatabaseHelper.getInstance(getContext());
		return true;
	}
  
  ...

  
  @Override
  public Cursor query(Uri uri, String[] projection,
          String selection, String[] selectionArgs, String sortOrder) {

	SQLiteDatabase db = mOpenHelper.getReadableDatabase();
      Cursor cursor = null;
      ...
  }
  
  ...