001/**
002 *
003 * Copyright 2018 Paul Schaub
004 *
005 * Licensed under the Apache License, Version 2.0 (the "License");
006 * you may not use this file except in compliance with the License.
007 * You may obtain a copy of the License at
008 *
009 *     http://www.apache.org/licenses/LICENSE-2.0
010 *
011 * Unless required by applicable law or agreed to in writing, software
012 * distributed under the License is distributed on an "AS IS" BASIS,
013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 * See the License for the specific language governing permissions and
015 * limitations under the License.
016 */
017package org.jivesoftware.smackx.omemo.exceptions;
018
019import org.jivesoftware.smackx.omemo.OmemoConfiguration;
020import org.jivesoftware.smackx.omemo.internal.OmemoDevice;
021
022/**
023 * Exception that signals, that a device is considered read-only.
024 * Read-only devices are devices that receive OMEMO messages, but do not send any.
025 * Those devices are weakening forward secrecy. For that reason, read-only devices are ignored after n messages have
026 * been sent without getting a reply back.
027 */
028public class ReadOnlyDeviceException extends Exception {
029    private static final long serialVersionUID = 1L;
030
031    private final OmemoDevice device;
032
033    /**
034     * Constructor.
035     * We do not need to hand over the current value of the message counter, as that value will always be equal to
036     * {@link OmemoConfiguration#getMaxReadOnlyMessageCount()}. Therefore providing the {@link OmemoDevice} should be
037     * enough.
038     *
039     * @param device device which is considered read-only.
040     */
041    public ReadOnlyDeviceException(OmemoDevice device) {
042        this.device = device;
043    }
044
045    /**
046     * Return the device in question.
047     *
048     * @return device that is read-only.
049     */
050    public OmemoDevice getDevice() {
051        return device;
052    }
053}