mirror of https://github.com/gchq/CyberChef.git
66 lines
1.9 KiB
JavaScript
66 lines
1.9 KiB
JavaScript
/**
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* @author tcode2k16 [tcode2k16@gmail.com]
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* @copyright Crown Copyright 2018
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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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import BigNumber from "bignumber.js";
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import Utils from "../Utils.mjs";
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/**
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* From Base62 operation
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*/
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class FromBase62 extends Operation {
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/**
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* FromBase62 constructor
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*/
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constructor() {
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super();
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this.name = "From Base62";
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this.module = "Default";
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this.description = "Base62 is a notation for encoding arbitrary byte data using a restricted set of symbols that can be conveniently used by humans and processed by computers. The high number base results in shorter strings than with the decimal or hexadecimal system.";
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this.infoURL = "https://wikipedia.org/wiki/List_of_numeral_systems";
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this.inputType = "string";
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this.outputType = "byteArray";
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this.args = [
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{
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name: "Alphabet",
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type: "string",
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value: "0-9A-Za-z"
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}
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];
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}
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/**
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* @param {string} input
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* @param {Object[]} args
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* @returns {byteArray}
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*/
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run(input, args) {
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if (input.length < 1) return [];
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const alphabet = Utils.expandAlphRange(args[0]).join("");
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const BN62 = BigNumber.clone({ ALPHABET: alphabet });
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const re = new RegExp("[^" + alphabet.replace(/[[\]\\\-^$]/g, "\\$&") + "]", "g");
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input = input.replace(re, "");
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// Read number in using Base62 alphabet
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const number = new BN62(input, 62);
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// Copy to new BigNumber object that uses the default alphabet
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const normalized = new BigNumber(number);
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// Convert to hex and add leading 0 if required
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let hex = normalized.toString(16);
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if (hex.length % 2 !== 0) hex = "0" + hex;
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return Utils.convertToByteArray(hex, "Hex");
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}
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}
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export default FromBase62;
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