CyberChef/src/core/operations/Adler32Checksum.mjs

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/**
* @author n1474335 [n1474335@gmail.com]
* @copyright Crown Copyright 2016
* @license Apache-2.0
*/
import Operation from "../Operation";
import Utils from "../Utils";
/**
* Adler-32 Checksum operation
*/
class Adler32Checksum extends Operation {
/**
* Adler32Checksum constructor
*/
constructor() {
super();
this.name = "Adler-32 Checksum";
this.module = "Hashing";
this.description = "Adler-32 is a checksum algorithm which was invented by Mark Adler in 1995, and is a modification of the Fletcher checksum. Compared to a cyclic redundancy check of the same length, it trades reliability for speed (preferring the latter).<br><br>Adler-32 is more reliable than Fletcher-16, and slightly less reliable than Fletcher-32.";
this.inputType = "byteArray";
this.outputType = "string";
this.args = [];
}
/**
* @param {byteArray} input
* @param {Object[]} args
* @returns {string}
*/
run(input, args) {
const MOD_ADLER = 65521;
let a = 1,
b = 0;
for (let i = 0; i < input.length; i++) {
a += input[i];
b += a;
}
a %= MOD_ADLER;
b %= MOD_ADLER;
return Utils.hex(((b << 16) | a) >>> 0, 8);
}
}
export default Adler32Checksum;