(JavaScript) Generate ECDSA Key and Get Details as XML

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

Note: This example requires Chilkat v11.0.0 or greater.

Note

This example is intended for running within a Chilkat.Js embedded JavaScript engine. All Chilkat JavaScript examples require Chilkat v11.4.0 or greater.

var success = false;

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

var ecc = new CkEcc();

// 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 CkPrng();
var entropy = fortuna.GetEntropy(32,"base64");
success = fortuna.AddEntropy(entropy,"base64");

var privKey = new CkPrivateKey();
success = ecc.GenKey("secp256k1",fortuna,privKey);
if (success == false) {
    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 CkAsn();
success = asn.LoadEncoded(privKey.GetPkcs1ENC("base64"),"base64");
if (success !== true) {
    console.log(asn.LastErrorText);
    return;
}

var xml = new CkXml();
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 CkCrypt2();
var privKeyHex = crypt.ReEncode(xml.GetChildContent("octets"),"base64","hex");

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