CyberChef/src/core/operations/FromBase32.mjs

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/**
* @author n1474335 [n1474335@gmail.com]
* @copyright Crown Copyright 2016
* @license Apache-2.0
*/
import Operation from "../Operation.mjs";
import Utils from "../Utils.mjs";
/**
* From Base32 operation
*/
class FromBase32 extends Operation {
/**
* FromBase32 constructor
*/
constructor() {
super();
this.name = "From Base32";
this.module = "Default";
this.description = "Base32 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. It uses a smaller set of characters than Base64, usually the uppercase alphabet and the numbers 2 to 7.";
this.infoURL = "https://wikipedia.org/wiki/Base32";
this.inputType = "string";
this.outputType = "byteArray";
this.args = [
{
name: "Alphabet",
type: "binaryString",
value: "A-Z2-7="
},
{
name: "Remove non-alphabet chars",
type: "boolean",
value: true
}
];
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this.checks = [
{
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pattern: "^(?:[A-Z2-7]{8})+(?:[A-Z2-7]{2}={6}|[A-Z2-7]{4}={4}|[A-Z2-7]{5}={3}|[A-Z2-7]{7}={1})?$",
flags: "",
args: ["A-Z2-7=", false]
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}
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];
}
/**
* @param {string} input
* @param {Object[]} args
* @returns {byteArray}
*/
run(input, args) {
if (!input) return [];
const alphabet = args[0] ?
Utils.expandAlphRange(args[0]).join("") : "ABCDEFGHIJKLMNOPQRSTUVWXYZ234567=",
removeNonAlphChars = args[1],
output = [];
let chr1, chr2, chr3, chr4, chr5,
enc1, enc2, enc3, enc4, enc5, enc6, enc7, enc8,
i = 0;
if (removeNonAlphChars) {
const re = new RegExp("[^" + alphabet.replace(/[\]\\\-^]/g, "\\$&") + "]", "g");
input = input.replace(re, "");
}
while (i < input.length) {
enc1 = alphabet.indexOf(input.charAt(i++));
enc2 = alphabet.indexOf(input.charAt(i++) || "=");
enc3 = alphabet.indexOf(input.charAt(i++) || "=");
enc4 = alphabet.indexOf(input.charAt(i++) || "=");
enc5 = alphabet.indexOf(input.charAt(i++) || "=");
enc6 = alphabet.indexOf(input.charAt(i++) || "=");
enc7 = alphabet.indexOf(input.charAt(i++) || "=");
enc8 = alphabet.indexOf(input.charAt(i++) || "=");
chr1 = (enc1 << 3) | (enc2 >> 2);
chr2 = ((enc2 & 3) << 6) | (enc3 << 1) | (enc4 >> 4);
chr3 = ((enc4 & 15) << 4) | (enc5 >> 1);
chr4 = ((enc5 & 1) << 7) | (enc6 << 2) | (enc7 >> 3);
chr5 = ((enc7 & 7) << 5) | enc8;
output.push(chr1);
if ((enc2 & 3) !== 0 || enc3 !== 32) output.push(chr2);
if ((enc4 & 15) !== 0 || enc5 !== 32) output.push(chr3);
if ((enc5 & 1) !== 0 || enc6 !== 32) output.push(chr4);
if ((enc7 & 7) !== 0 || enc8 !== 32) output.push(chr5);
}
return output;
}
}
export default FromBase32;