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authorAnton Tananaev <anton.tananaev@gmail.com>2019-03-31 22:35:39 -0700
committerAnton Tananaev <anton.tananaev@gmail.com>2019-03-31 22:35:39 -0700
commit59416923dcb3a756eaf532cc4259f2f6625c0762 (patch)
tree9082dae6616deac8fda432b7bfd80e4a52b6d9dc /src/main/java/org/traccar/helper/Checksum.java
parent79a129dd6327d932133d6b9a50190d3f4927bff9 (diff)
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Convert project to gradle
Diffstat (limited to 'src/main/java/org/traccar/helper/Checksum.java')
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1 files changed, 200 insertions, 0 deletions
diff --git a/src/main/java/org/traccar/helper/Checksum.java b/src/main/java/org/traccar/helper/Checksum.java
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+/*
+ * Copyright 2012 - 2018 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.helper;
+
+import java.nio.ByteBuffer;
+import java.nio.charset.StandardCharsets;
+import java.util.zip.CRC32;
+
+public final class Checksum {
+
+ private Checksum() {
+ }
+
+ public static class Algorithm {
+
+ private int poly;
+ private int init;
+ private boolean refIn;
+ private boolean refOut;
+ private int xorOut;
+ private int[] table;
+
+ public Algorithm(int bits, int poly, int init, boolean refIn, boolean refOut, int xorOut) {
+ this.poly = poly;
+ this.init = init;
+ this.refIn = refIn;
+ this.refOut = refOut;
+ this.xorOut = xorOut;
+ this.table = bits == 8 ? initTable8() : initTable16();
+ }
+
+ private int[] initTable8() {
+ int[] table = new int[256];
+ int crc;
+ for (int i = 0; i < 256; i++) {
+ crc = i;
+ for (int j = 0; j < 8; j++) {
+ boolean bit = (crc & 0x80) != 0;
+ crc <<= 1;
+ if (bit) {
+ crc ^= poly;
+ }
+ }
+ table[i] = crc & 0xFF;
+ }
+ return table;
+ }
+
+ private int[] initTable16() {
+ int[] table = new int[256];
+ int crc;
+ for (int i = 0; i < 256; i++) {
+ crc = i << 8;
+ for (int j = 0; j < 8; j++) {
+ boolean bit = (crc & 0x8000) != 0;
+ crc <<= 1;
+ if (bit) {
+ crc ^= poly;
+ }
+ }
+ table[i] = crc & 0xFFFF;
+ }
+ return table;
+ }
+
+ }
+
+ private static int reverse(int value, int bits) {
+ int result = 0;
+ for (int i = 0; i < bits; i++) {
+ result = (result << 1) | (value & 1);
+ value >>= 1;
+ }
+ return result;
+ }
+
+ public static int crc8(Algorithm algorithm, ByteBuffer buf) {
+ int crc = algorithm.init;
+ while (buf.hasRemaining()) {
+ int b = buf.get() & 0xFF;
+ if (algorithm.refIn) {
+ b = reverse(b, 8);
+ }
+ crc = algorithm.table[(crc & 0xFF) ^ b];
+ }
+ if (algorithm.refOut) {
+ crc = reverse(crc, 8);
+ }
+ return (crc ^ algorithm.xorOut) & 0xFF;
+ }
+
+ public static int crc16(Algorithm algorithm, ByteBuffer buf) {
+ int crc = algorithm.init;
+ while (buf.hasRemaining()) {
+ int b = buf.get() & 0xFF;
+ if (algorithm.refIn) {
+ b = reverse(b, 8);
+ }
+ crc = (crc << 8) ^ algorithm.table[((crc >> 8) & 0xFF) ^ b];
+ }
+ if (algorithm.refOut) {
+ crc = reverse(crc, 16);
+ }
+ return (crc ^ algorithm.xorOut) & 0xFFFF;
+ }
+
+ public static final Algorithm CRC8_EGTS = new Algorithm(8, 0x31, 0xFF, false, false, 0x00);
+ public static final Algorithm CRC8_ROHC = new Algorithm(8, 0x07, 0xFF, true, true, 0x00);
+
+ public static final Algorithm CRC16_IBM = new Algorithm(16, 0x8005, 0x0000, true, true, 0x0000);
+ public static final Algorithm CRC16_X25 = new Algorithm(16, 0x1021, 0xFFFF, true, true, 0xFFFF);
+ public static final Algorithm CRC16_MODBUS = new Algorithm(16, 0x8005, 0xFFFF, true, true, 0x0000);
+ public static final Algorithm CRC16_CCITT_FALSE = new Algorithm(16, 0x1021, 0xFFFF, false, false, 0x0000);
+ public static final Algorithm CRC16_KERMIT = new Algorithm(16, 0x1021, 0x0000, true, true, 0x0000);
+ public static final Algorithm CRC16_XMODEM = new Algorithm(16, 0x1021, 0x0000, false, false, 0x0000);
+
+ public static int crc32(ByteBuffer buf) {
+ CRC32 checksum = new CRC32();
+ while (buf.hasRemaining()) {
+ checksum.update(buf.get());
+ }
+ return (int) checksum.getValue();
+ }
+
+ public static int xor(ByteBuffer buf) {
+ int checksum = 0;
+ while (buf.hasRemaining()) {
+ checksum ^= buf.get();
+ }
+ return checksum;
+ }
+
+ public static int xor(String string) {
+ byte checksum = 0;
+ for (byte b : string.getBytes(StandardCharsets.US_ASCII)) {
+ checksum ^= b;
+ }
+ return checksum;
+ }
+
+ public static String nmea(String msg) {
+ int checksum = 0;
+ byte[] bytes = msg.getBytes(StandardCharsets.US_ASCII);
+ for (int i = 1; i < bytes.length; i++) {
+ checksum ^= bytes[i];
+ }
+ return String.format("*%02x", checksum).toUpperCase();
+ }
+
+ public static int sum(ByteBuffer buf) {
+ byte checksum = 0;
+ while (buf.hasRemaining()) {
+ checksum += buf.get();
+ }
+ return checksum;
+ }
+
+ public static String sum(String msg) {
+ byte checksum = 0;
+ for (byte b : msg.getBytes(StandardCharsets.US_ASCII)) {
+ checksum += b;
+ }
+ return String.format("%02X", checksum).toUpperCase();
+ }
+
+ public static long luhn(long imei) {
+ long checksum = 0;
+ long remain = imei;
+
+ for (int i = 0; remain != 0; i++) {
+ long digit = remain % 10;
+
+ if (i % 2 == 0) {
+ digit *= 2;
+ if (digit >= 10) {
+ digit = 1 + (digit % 10);
+ }
+ }
+
+ checksum += digit;
+ remain /= 10;
+ }
+
+ return (10 - (checksum % 10)) % 10;
+ }
+
+}