(Node.js) Generate ECDSA Key and Get Details as XML

Demonstrates how to generate an ECC key and gets the parts as XML.

Install Chilkat for Node.js and Electron using npm at Chilkat npm packages for Node.js Chilkat npm packages for Electron on Windows, Linux, MacOS

var os = require('os');
if (os.platform() == 'win32') {  
  var chilkat = require('@chilkat/ck-node23-win64'); 
} else if (os.platform() == 'linux') {
    if (os.arch() == 'arm') {
        var chilkat = require('@chilkat/ck-node23-linux-arm');
    } else if (os.arch() == 'arm64') {
        var chilkat = require('@chilkat/ck-node23-linux-arm64');
    } else {
        var chilkat = require('@chilkat/ck-node23-linux-x64');
    }
} else if (os.platform() == 'darwin') {
  var chilkat = require('@chilkat/ck-node23-mac-universal');
}

function chilkatExample() {

    // This requires the Chilkat API to have been previously unlocked.
    // See Global Unlock Sample for sample code.

    var ecc = new chilkat.Ecc();

    // Generate a random ECC private key on the secp256k1 curve.
    // Chilkat also supports other curves, such as secp384r1, secp521r1, and secp256r1.

    // Create a Fortuna PRNG and seed it with system entropy.
    // This will be our source of random data for generating the ECC private key.
    var fortuna = new chilkat.Prng();
    var entropy = fortuna.GetEntropy(32,"base64");
    var success = fortuna.AddEntropy(entropy,"base64");

    // privKey: PrivateKey
    var privKey = ecc.GenEccKey("secp256k1",fortuna);
    if (ecc.LastMethodSuccess !== true) {
        console.log(ecc.LastErrorText);
        return;
    }

    // An EC private key has this ASN.1
    // ECPrivateKey ::= SEQUENCE {
    //     version        INTEGER { ecPrivkeyVer1(1) } (ecPrivkeyVer1),
    //     privateKey     OCTET STRING,
    //     parameters [0] ECParameters {{ NamedCurve }} OPTIONAL,
    //     publicKey  [1] BIT STRING OPTIONAL (This is the ANSI X9.63 public key format.)

    var asn = new chilkat.Asn();
    success = asn.LoadEncoded(privKey.GetPkcs1ENC("base64"),"base64");
    if (success !== true) {
        console.log(asn.LastErrorText);
        return;
    }

    var xml = new chilkat.Xml();
    xml.LoadXml(asn.AsnToXml());

    console.log(xml.GetXml());

    // The XML looks like this:
    // <?xml version="1.0" encoding="utf-8" ?>
    // <sequence>
    //     <int>01</int>
    //     <octets>JgJvBG+3wletkJab8iXAkpz0O8/AgWZSpkYVcB7SpnU=</octets>
    //     <contextSpecific tag="0" constructed="1">
    //         <oid>1.3.132.0.10</oid>
    //     </contextSpecific>
    // </sequence>

    // The 32-byte private key is in the octets..
    // Get it as hex.
    var crypt = new chilkat.Crypt2();
    var privKeyHex = crypt.ReEncode(xml.GetChildContent("octets"),"base64","hex");

    console.log("EC private key as hex = " + privKeyHex);


}

chilkatExample();