3b3eb2f78e
Implements Base26 encoding/decoding using uppercase A-Z as digits (A=0, B=1, ..., Z=25). Input bytes are interpreted as a big-endian unsigned integer and converted to/from radix 26. Includes tests for the reference vector (EAT -> JYGBS), round-trips, empty input, zero bytes, and binary data. Closes gchq/CyberChef#1511
59 lines
1.4 KiB
JavaScript
59 lines
1.4 KiB
JavaScript
/**
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* @author NOVA-Openclaw
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* @copyright Crown Copyright 2026
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* @license Apache-2.0
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*/
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import Operation from "../Operation.mjs";
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/**
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* To Base26 operation
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*/
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class ToBase26 extends Operation {
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/**
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* ToBase26 constructor
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*/
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constructor() {
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super();
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this.name = "To Base26";
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this.module = "Default";
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this.description = "Base26 is a notation for encoding arbitrary byte data using the uppercase letters A-Z. The input bytes are interpreted as a big-endian unsigned integer, which is then represented in radix 26 using A=0, B=1, ..., Z=25.";
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this.infoURL = "https://wikipedia.org/wiki/List_of_numeral_systems";
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this.inputType = "ArrayBuffer";
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this.outputType = "string";
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this.args = [];
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}
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/**
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* @param {ArrayBuffer} input
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* @param {Object[]} args
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* @returns {string}
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*/
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run(input, args) {
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input = new Uint8Array(input);
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if (input.length < 1) return "";
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const ALPHABET = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
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let number = 0n;
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for (const byte of input) {
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number = (number << 8n) | BigInt(byte);
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}
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if (number === 0n) return ALPHABET[0];
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let output = "";
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while (number > 0n) {
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output = ALPHABET[Number(number % 26n)] + output;
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number /= 26n;
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}
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return output;
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}
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}
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export default ToBase26;
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