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ronnievsmith/jws-hs256.mjs

Last active August 23, 2023 02:33
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  1. Ronnie Royston revised this gist Aug 23, 2023. No changes.
  2. Ronnie Royston created this gist Aug 22, 2023.
    97 changes: 97 additions & 0 deletions jws-hs256.mjs
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    Original file line number Diff line number Diff line change
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    import { Buffer } from 'node:buffer';
    import fs from "node:fs";
    import url from 'node:url';
    import path from "node:path";
    const {createHmac, generateKey} = await import('node:crypto');
    var claims = {name:"Joe",roles:["member","admin"]};
    var secretKey;

    (async function () {
    secretKey = await generateSecretKey();
    let jws = await returnJWS(claims);
    console.log("\x1b[37mYour JWS token is: " + consoleString(jws));
    console.log("Paste JSON Web Token In Terminal Then Press Enter.")
    })();

    function returnJWS(claims){
    let headerObject = {
    alg: 'HS256',
    typ: 'JWT',
    kid: 'public'
    };
    let headerString = JSON.stringify(headerObject);
    let encodedHeader = Buffer.from(headerString).toString('base64url');
    let payloadString = JSON.stringify(claims);
    let encodedPayload = Buffer.from(payloadString).toString('base64url');
    const hmac = createHmac('sha256', secretKey);
    hmac.update(encodedHeader + '.' + encodedPayload);
    let signature = hmac.digest('base64url');

    let jsonWebToken = encodedHeader + '.' + encodedPayload + '.' + signature;
    return jsonWebToken;
    }

    function validateJWS(jwt){
    try {
    let jwtParts = jwt.split('.');
    let jwtHeader = jwtParts[0];
    let jwtPayload = jwtParts[1];
    let jwtSignature = jwtParts[2].trim();
    let signature;
    let header = JSON.parse(Buffer.from(jwtHeader, 'base64url').toString('utf-8'));
    let alg = header.alg;
    if(alg === "HS256"){
    const hmac = createHmac('sha256', secretKey);
    hmac.update(jwtHeader + '.' + jwtPayload);
    signature = hmac.digest('base64url').trim();
    console.log(signature)
    console.log(jwtSignature)
    if(signature == jwtSignature) {
    return Buffer.from(jwtPayload, 'base64url').toString('utf-8')
    } else {
    return "\x1b[31mInvalid Token!\x1b[37m";
    }
    } else {
    throw (error)
    }
    } catch (e) {
    console.log (e);
    return "\x1b[31mInvalid Token!\x1b[37m";
    }
    }

    function generateSecretKey () {
    return new Promise(function(resolve, reject) {
    generateKey('aes', { length: 256 }, (err, key) => {
    if (err) {
    reject (err);
    }
    resolve (key)
    });
    });
    }

    export default {returnJWS, validateJWS};

    process.stdin.setEncoding('utf8');
    process.stdin.on('readable', async () => {
    let chunk;
    while ((chunk = process.stdin.read()) !== null) {
    console.log(await validateJWS(chunk));
    }
    });

    function consoleString(token){
    let tokenParts = token.split(/(\.)/);
    let colors = ["32m","31m","33m","34m","36m"];
    let color = "\x1b[X";
    let str = ""
    tokenParts.forEach(function(part,index){
    if(part != "."){
    str += color.replace("X",colors.shift())
    }
    str += part;
    str += "\x1b[37m"
    })
    return str;
    }