/* * Copyright 2016 - 2017 Anton Tananaev (anton@traccar.org) * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ package org.traccar.protocol; import org.jboss.netty.buffer.ChannelBuffer; import org.jboss.netty.buffer.ChannelBuffers; import org.jboss.netty.channel.Channel; import org.traccar.BaseProtocolDecoder; import org.traccar.DeviceSession; import org.traccar.helper.DataConverter; import org.traccar.helper.UnitsConverter; import org.traccar.model.Position; import javax.crypto.Cipher; import javax.crypto.spec.IvParameterSpec; import javax.crypto.spec.SecretKeySpec; import java.net.SocketAddress; import java.nio.ByteOrder; import java.nio.charset.StandardCharsets; import java.util.Date; import java.util.LinkedList; import java.util.List; public class At2000ProtocolDecoder extends BaseProtocolDecoder { private static final int BLOCK_LENGTH = 16; public At2000ProtocolDecoder(At2000Protocol protocol) { super(protocol); } public static final int MSG_ACKNOWLEDGEMENT = 0x00; public static final int MSG_DEVICE_ID = 0x01; public static final int MSG_TRACK_REQUEST = 0x88; public static final int MSG_TRACK_RESPONSE = 0x89; public static final int MSG_SESSION_END = 0x0c; private Cipher cipher; private static void sendRequest(Channel channel) { if (channel != null) { ChannelBuffer response = ChannelBuffers.directBuffer(ByteOrder.LITTLE_ENDIAN, BLOCK_LENGTH); response.writeByte(MSG_TRACK_REQUEST); response.writeMedium(ChannelBuffers.swapMedium(0)); response.writerIndex(BLOCK_LENGTH); channel.write(response); } } @Override protected Object decode( Channel channel, SocketAddress remoteAddress, Object msg) throws Exception { ChannelBuffer buf = (ChannelBuffer) msg; if (buf.getUnsignedByte(buf.readerIndex()) == 0x01) { buf.readUnsignedByte(); // codec id } int type = buf.readUnsignedByte(); buf.readUnsignedMedium(); // length buf.skipBytes(BLOCK_LENGTH - 1 - 3); if (type == MSG_DEVICE_ID) { String imei = buf.readBytes(15).toString(StandardCharsets.US_ASCII); if (getDeviceSession(channel, remoteAddress, imei) != null) { byte[] iv = new byte[BLOCK_LENGTH]; buf.readBytes(iv); IvParameterSpec ivSpec = new IvParameterSpec(iv); SecretKeySpec keySpec = new SecretKeySpec( DataConverter.parseHex("000102030405060708090a0b0c0d0e0f"), "AES"); cipher = Cipher.getInstance("AES/CBC/NoPadding"); cipher.init(Cipher.DECRYPT_MODE, keySpec, ivSpec); byte[] data = new byte[BLOCK_LENGTH]; buf.readBytes(data); cipher.update(data); } } else if (type == MSG_TRACK_RESPONSE) { DeviceSession deviceSession = getDeviceSession(channel, remoteAddress); if (deviceSession == null) { return null; } if (buf.capacity() <= BLOCK_LENGTH) { return null; // empty message } byte[] data = new byte[buf.capacity() - BLOCK_LENGTH]; buf.readBytes(data); buf = ChannelBuffers.wrappedBuffer(ByteOrder.LITTLE_ENDIAN, cipher.update(data)); List<Position> positions = new LinkedList<>(); while (buf.readableBytes() >= 63) { Position position = new Position(getProtocolName()); position.setDeviceId(deviceSession.getDeviceId()); buf.readUnsignedShort(); // index buf.readUnsignedShort(); // reserved position.setValid(true); position.setTime(new Date(buf.readLong() * 1000)); position.setLatitude(buf.readFloat()); position.setLongitude(buf.readFloat()); position.setAltitude(buf.readFloat()); position.setSpeed(UnitsConverter.knotsFromKph(buf.readFloat())); position.setCourse(buf.readFloat()); buf.readUnsignedInt(); // geozone event buf.readUnsignedInt(); // io events buf.readUnsignedInt(); // geozone value buf.readUnsignedInt(); // io values buf.readUnsignedShort(); // operator position.set(Position.PREFIX_ADC + 1, buf.readUnsignedShort()); position.set(Position.PREFIX_ADC + 1, buf.readUnsignedShort()); position.set(Position.KEY_POWER, buf.readUnsignedShort() * 0.001); buf.readUnsignedShort(); // cid position.set(Position.KEY_RSSI, buf.readUnsignedByte()); buf.readUnsignedByte(); // current profile position.set(Position.KEY_BATTERY, buf.readUnsignedByte()); position.set(Position.PREFIX_TEMP + 1, buf.readUnsignedByte()); position.set(Position.KEY_SATELLITES, buf.readUnsignedByte()); positions.add(position); } return positions; } if (type == MSG_DEVICE_ID) { sendRequest(channel); } return null; } }