bitcoin-encrypt-decrypt-sign-verify.js

var crypto = require('crypto');
var bitcoin = require('bitcoinjs-lib')


var bitcoinMessage = require('bitcoinjs-message')

function doVerify() {

    var wif;

    var keyPair;

    wif = "KznJAT7suZ7UhX2kp2FxCjhJR54SGVfdySeLriwpeHtQFs7TcLBU";

    if (!wif) {
        keyPair = bitcoin.ECPair.makeRandom();
        wif = keyPair.toWIF();
        console.log("WIF", wif);
    }
    else {

        keyPair = bitcoin.ECPair.fromWIF(wif)

        var p2pkh_Obj = bitcoin.payments.p2pkh({
            pubkey: keyPair.publicKey
        });

        var address = p2pkh_Obj.address;

        var privateKey = keyPair.privateKey
        var message = makeRandomMessage();


        var signature = bitcoinMessage.sign(message, privateKey, keyPair.compressed).toString('base64')

        var verify = bitcoinMessage.verify(message, address, signature);

        console.log("WIF", wif)
        console.log("address", address);
        console.log("message", message)
        console.log("signature", signature)
        console.log("verify", verify)

    }


    function makeRandomMessage() {
        var kp = bitcoin.ECPair.makeRandom();
        var p2pkh_Obj = bitcoin.payments.p2pkh({
            pubkey: kp.publicKey
        });

        return p2pkh_Obj.address;
    }
}

function doCryptoTest() {

    var text = "this is a message";


    var Alice_keyPair = bitcoin.ECPair.makeRandom();
    var Alice_wif = Alice_keyPair.toWIF();


    var Bob_keyPair = bitcoin.ECPair.makeRandom();
    var Bob_wif = Bob_keyPair.toWIF();


    var pubB = new Buffer(Bob_keyPair.publicKey.toString("hex"), 'hex');

    var ecdhA = crypto.createECDH('secp256k1');
    ecdhA.generateKeys('hex', 'compressed');
    ecdhA.setPrivateKey(Alice_keyPair.privateKey.toString("hex"), 'hex');

    var secretA = ecdhA.computeSecret(pubB, 'hex').toString('hex');

    console.log("secretA", secretA)




    var pubA = new Buffer(Alice_keyPair.publicKey.toString("hex"), 'hex');

    var ecdhB = crypto.createECDH('secp256k1');
    ecdhB.generateKeys('hex', 'compressed');
    ecdhB.setPrivateKey(Bob_keyPair.privateKey.toString("hex"), 'hex');

    var secretB = ecdhB.computeSecret(pubA, 'hex').toString('hex');

    console.log("secretB", secretB)


    //Alice encrypts message to Bob using AES
    var cipher = crypto.createCipher('aes-256-ctr', secretA);
    var ecrypted = cipher.update(text, 'utf8', 'hex');
    ecrypted += cipher.final('hex');

    console.log(ecrypted)

    var decipher = crypto.createCipher('aes-256-ctr', secretB);
    var Dcrypted = decipher.update(ecrypted, 'hex', 'utf8');
    Dcrypted += decipher.final('utf8');


    console.log(Dcrypted)


}

doVerify();
doCryptoTest()