(C# UWP/WinRT) Generate ECDSA Key and Get Details as XML

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

Chilkat Universal Windows Platform (UWP) / WinRT Downloads Chilkat for the Universal Windows Platform (UWP)

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

Chilkat.Ecc 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.
Chilkat.Prng fortuna = new Chilkat.Prng();
string entropy = fortuna.GetEntropy(32,"base64");
bool success = fortuna.AddEntropy(entropy,"base64");

Chilkat.PrivateKey privKey = ecc.GenEccKey("secp256k1",fortuna);
if (ecc.LastMethodSuccess != true) {
    Debug.WriteLine(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.)

Chilkat.Asn asn = new Chilkat.Asn();
success = asn.LoadEncoded(privKey.GetPkcs1ENC("base64"),"base64");
if (success != true) {
    Debug.WriteLine(asn.LastErrorText);
    return;
}

Chilkat.Xml xml = new Chilkat.Xml();
xml.LoadXml(asn.AsnToXml());

Debug.WriteLine(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.
Chilkat.Crypt2 crypt = new Chilkat.Crypt2();
string privKeyHex = crypt.ReEncode(xml.GetChildContent("octets"),"base64","hex");

Debug.WriteLine("EC private key as hex = " + privKeyHex);