CyberChef/src/core/operations/JWTDecode.mjs

/**
 * @author gchq77703 []
 * @copyright Crown Copyright 2018
 * @license Apache-2.0
 */

import Operation from "../Operation.mjs";
import jwt from "jsonwebtoken";
import OperationError from "../errors/OperationError.mjs";
import moment from "moment-timezone";

/**
 * JWT Decode operation
 */
class JWTDecode extends Operation {

    /**
     * JWTDecode constructor
     */
    constructor() {
        super();

        this.name = "JWT Decode";
        this.module = "Crypto";
        this.description = "Decodes a JSON Web Token <b>without</b> checking whether the provided secret / private key is valid. Use 'JWT Verify' to check if the signature is valid as well.";
        this.infoURL = "https://wikipedia.org/wiki/JSON_Web_Token";
        this.inputType = "string";
        this.outputType = "JSON";
        this.args = [
            {
                "name": "Show/Hide dates",
                "type": "boolean",
                "value": false
            }
        ];
        this.checks = [
            {
                pattern: "^ey([A-Za-z0-9_-]+)\\.ey([A-Za-z0-9_-]+)\\.([A-Za-z0-9_-]+)$",
                flags: "",
                args: []
            },
        ];
    }

    /**
     * @param {string} input
     * @param {Object[]} args
     * @returns {JSON}
     */
    run(input, args) {
        try {
            const formatAsDate = args[0];
            const decoded = jwt.decode(input, {
                json: true,
                complete: true
            });

            if (formatAsDate) {
                const payload = {...decoded.payload};
                if (payload.iat) {
                    payload.iat = payload.iat + " ("+moment.unix(payload.iat).tz("UTC").format("ddd D MMMM YYYY HH:mm:ss") + " UTC)";
                }
                if (payload.exp) {
                    payload.exp = payload.exp + " ("+moment.unix(payload.exp).tz("UTC").format("ddd D MMMM YYYY HH:mm:ss") + " UTC)";
                }
                if (payload.nbf) {
                    payload.nbf = payload.nbf + " ("+moment.unix(payload.nbf).tz("UTC").format("ddd D MMMM YYYY HH:mm:ss") + " UTC)";
                }

                return payload;
            }

            return decoded.payload;
        } catch (err) {
            throw new OperationError(err);
        }
    }

}

export default JWTDecode;