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Macide Celik 2019-10-28 15:33:06 +03:00 • committed by GitHub
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src/core/operations/CRC8Checksum.mjs
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/**
* @author mshwed [m@ttshwed.com]
* @copyright Crown Copyright 2019
* @license Apache-2.0
*/
import Operation from "../Operation.mjs";
import OperationError from "../errors/OperationError.mjs";
import { toHexFast } from "../lib/Hex.mjs";
/**
* CRC-8 Checksum operation
*/
class CRC8Checksum extends Operation {
/**
* CRC8Checksum constructor
*/
constructor() {
super();
this.name = "CRC-8 Checksum";
this.module = "Crypto";
this.description = "A cyclic redundancy check (CRC) is an error-detecting code commonly used in digital networks and storage devices to detect accidental changes to raw data.<br><br>The CRC was invented by W. Wesley Peterson in 1961.";
this.infoURL = "https://wikipedia.org/wiki/Cyclic_redundancy_check";
this.inputType = "ArrayBuffer";
this.outputType = "string";
this.args = [
{
"name": "Algorithm",
"type": "option",
"value": [
"CRC-8",
"CRC-8/CDMA2000",
"CRC-8/DARC",
"CRC-8/DVB-S2",
"CRC-8/EBU",
"CRC-8/I-CODE",
"CRC-8/ITU",
"CRC-8/MAXIM",
"CRC-8/ROHC",
"CRC-8/WCDMA"
]
}
];
}
/**
* Generates the pre-computed lookup table for byte division
*
* @param polynomial
*/
calculateCRC8LookupTable(polynomial) {
const crc8Table = new Uint8Array(256);
let currentByte;
for (let i = 0; i < 256; i++) {
currentByte = i;
for (let bit = 0; bit < 8; bit++) {
if ((currentByte & 0x80) !== 0) {
currentByte <<= 1;
currentByte ^= polynomial;
} else {
currentByte <<= 1;
}
}
crc8Table[i] = currentByte;
}
return crc8Table;
}
/**
* Calculates the CRC-8 Checksum from an input
*
* @param {ArrayBuffer} input
* @param {number} polynomial
* @param {number} initializationValue
* @param {boolean} inputReflection
* @param {boolean} outputReflection
* @param {number} xorOut
*/
calculateCRC8(input, polynomial, initializationValue, inputReflection, outputReflection, xorOut) {
const crcSize = 8;
const crcTable = this.calculateCRC8LookupTable(polynomial);
let crc = initializationValue !== 0 ? initializationValue : 0;
let currentByte, position;
input = new Uint8Array(input);
for (const inputByte of input) {
currentByte = inputReflection ? this.reverseBits(inputByte, crcSize) : inputByte;
position = (currentByte ^ crc) & 255;
crc = crcTable[position];
}
crc = outputReflection ? this.reverseBits(crc, crcSize) : crc;
if (xorOut !== 0) crc = crc ^ xorOut;
return toHexFast(new Uint8Array([crc]));
}
/**
* Reverse the bits for a given input byte.
*
* @param {number} input
*/
reverseBits(input, hashSize) {
let reversedByte = 0;
for (let i = hashSize - 1; i >= 0; i--) {
reversedByte |= ((input & 1) << i);
input >>= 1;
}
return reversedByte;
}
/**
* @param {ArrayBuffer} input
* @param {Object[]} args
* @returns {string}
*/
run(input, args) {
const algorithm = args[0];
switch (algorithm) {
case "CRC-8":
return this.calculateCRC8(input, 0x7, 0x0, false, false, 0x0);
case "CRC-8/CDMA2000":
return this.calculateCRC8(input, 0x9B, 0xFF, false, false, 0x0);
case "CRC-8/DARC":
return this.calculateCRC8(input, 0x39, 0x0, true, true, 0x0);
case "CRC-8/DVB-S2":
return this.calculateCRC8(input, 0xD5, 0x0, false, false, 0x0);
case "CRC-8/EBU":
return this.calculateCRC8(input, 0x1D, 0xFF, true, true, 0x0);
case "CRC-8/I-CODE":
return this.calculateCRC8(input, 0x1D, 0xFD, false, false, 0x0);
case "CRC-8/ITU":
return this.calculateCRC8(input, 0x7, 0x0, false, false, 0x55);
case "CRC-8/MAXIM":
return this.calculateCRC8(input, 0x31, 0x0, true, true, 0x0);
case "CRC-8/ROHC":
return this.calculateCRC8(input, 0x7, 0xFF, true, true, 0x0);
case "CRC-8/WCDMA":
return this.calculateCRC8(input, 0x9B, 0x0, true, true, 0x0);
default:
throw new OperationError("Unknown checksum algorithm");
}
}
}
export default CRC8Checksum;