ReadOnlyDeviceException.java

  1. /**
  2.  *
  3.  * Copyright 2018 Paul Schaub
  4.  *
  5.  * Licensed under the Apache License, Version 2.0 (the "License");
  6.  * you may not use this file except in compliance with the License.
  7.  * You may obtain a copy of the License at
  8.  *
  9.  *     http://www.apache.org/licenses/LICENSE-2.0
  10.  *
  11.  * Unless required by applicable law or agreed to in writing, software
  12.  * distributed under the License is distributed on an "AS IS" BASIS,
  13.  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  14.  * See the License for the specific language governing permissions and
  15.  * limitations under the License.
  16.  */
  17. package org.jivesoftware.smackx.omemo.exceptions;

  18. import org.jivesoftware.smackx.omemo.OmemoConfiguration;
  19. import org.jivesoftware.smackx.omemo.internal.OmemoDevice;

  20. /**
  21.  * Exception that signals, that a device is considered read-only.
  22.  * Read-only devices are devices that receive OMEMO messages, but do not send any.
  23.  * Those devices are weakening forward secrecy. For that reason, read-only devices are ignored after n messages have
  24.  * been sent without getting a reply back.
  25.  */
  26. public class ReadOnlyDeviceException extends Exception {
  27.     private static final long serialVersionUID = 1L;

  28.     private final OmemoDevice device;

  29.     /**
  30.      * Constructor.
  31.      * We do not need to hand over the current value of the message counter, as that value will always be equal to
  32.      * {@link OmemoConfiguration#getMaxReadOnlyMessageCount()}. Therefore providing the {@link OmemoDevice} should be
  33.      * enough.
  34.      *
  35.      * @param device device which is considered read-only.
  36.      */
  37.     public ReadOnlyDeviceException(OmemoDevice device) {
  38.         this.device = device;
  39.     }

  40.     /**
  41.      * Return the device in question.
  42.      *
  43.      * @return device that is read-only.
  44.      */
  45.     public OmemoDevice getDevice() {
  46.         return device;
  47.     }
  48. }