CyberChef/src/core/operations/LuhnChecksum.mjs

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/**
* @author n1073645 [n1073645@gmail.com]
* @copyright Crown Copyright 2020
* @license Apache-2.0
*/
import Operation from "../Operation.mjs";
import OperationError from "../errors/OperationError.mjs";
/**
* Luhn Checksum operation
*/
class LuhnChecksum extends Operation {
/**
* LuhnChecksum constructor
*/
constructor() {
super();
this.name = "Luhn Checksum";
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this.module = "Default";
this.description = "The Luhn algorithm, also known as the modulus 10 or mod 10 algorithm, is a simple checksum formula used to validate a variety of identification numbers, such as credit card numbers, IMEI numbers and Canadian Social Insurance Numbers.";
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this.infoURL = "https://wikipedia.org/wiki/Luhn_algorithm";
this.inputType = "string";
this.outputType = "string";
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this.args = [];
}
/**
* Generates the Luhn Checksum from the input.
*
* @param {string} inputStr
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* @returns {number}
*/
checksum(inputStr) {
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let even = false;
return inputStr.split("").reverse().reduce((acc, elem) => {
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// Convert element to integer.
let temp = parseInt(elem, 10);
// If element is not an integer.
if (isNaN(temp))
throw new OperationError("Character: " + elem + " is not a digit.");
// If element is in an even position
if (even) {
// Double the element and add the quotient and remainder together.
temp = 2 * elem;
temp = Math.floor(temp/10) + (temp % 10);
}
even = !even;
return acc + temp;
}, 0) % 10;
}
/**
* @param {string} input
* @param {Object[]} args
* @returns {string}
*/
run(input, args) {
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if (!input) return "";
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const checkSum = this.checksum(input);
let checkDigit = this.checksum(input + "0");
checkDigit = checkDigit === 0 ? 0 : (10-checkDigit);
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return `Checksum: ${checkSum}
Checkdigit: ${checkDigit}
Luhn Validated String: ${input + "" + checkDigit}`;
}
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}
export default LuhnChecksum;