CyberChef/src/core/lib/Ciphers.mjs

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/**
* Cipher functions.
*
* @author Matt C [matt@artemisbot.uk]
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* @author n1474335 [n1474335@gmail.com]
*
* @copyright Crown Copyright 2018
* @license Apache-2.0
*
*/
import OperationError from "../errors/OperationError.mjs";
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import CryptoJS from "crypto-js";
/**
* Affine Cipher Encode operation.
*
* @author Matt C [matt@artemisbot.uk]
* @param {string} input
* @param {Object[]} args
* @returns {string}
*/
export function affineEncode(input, args) {
const alphabet = "abcdefghijklmnopqrstuvwxyz",
a = args[0],
b = args[1];
let output = "";
if (!/^\+?(0|[1-9]\d*)$/.test(a) || !/^\+?(0|[1-9]\d*)$/.test(b)) {
throw new OperationError("The values of a and b can only be integers.");
}
for (let i = 0; i < input.length; i++) {
if (alphabet.indexOf(input[i]) >= 0) {
// Uses the affine function ax+b % m = y (where m is length of the alphabet)
output += alphabet[((a * alphabet.indexOf(input[i])) + b) % 26];
} else if (alphabet.indexOf(input[i].toLowerCase()) >= 0) {
// Same as above, accounting for uppercase
output += alphabet[((a * alphabet.indexOf(input[i].toLowerCase())) + b) % 26].toUpperCase();
} else {
// Non-alphabetic characters
output += input[i];
}
}
return output;
}
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/**
* Generates a polybius square for the given keyword
*
* @private
* @author Matt C [matt@artemisbot.uk]
* @param {string} keyword - Must be upper case
* @returns {string}
*/
export function genPolybiusSquare (keyword) {
const alpha = "ABCDEFGHIKLMNOPQRSTUVWXYZ",
polArray = `${keyword}${alpha}`.split("").unique(),
polybius = [];
for (let i = 0; i < 5; i++) {
polybius[i] = polArray.slice(i*5, i*5 + 5);
}
return polybius;
}
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/**
* A mapping of string formats to their classes in the CryptoJS library.
*
* @private
* @constant
*/
export const format = {
"Hex": CryptoJS.enc.Hex,
"Base64": CryptoJS.enc.Base64,
"UTF8": CryptoJS.enc.Utf8,
"UTF16": CryptoJS.enc.Utf16,
"UTF16LE": CryptoJS.enc.Utf16LE,
"UTF16BE": CryptoJS.enc.Utf16BE,
"Latin1": CryptoJS.enc.Latin1,
};