(Delphi ActiveX) Generate ECDSA Key and Get Details as XML

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

Chilkat for Delphi Downloads Chilkat ActiveX DLL for Delphi Chilkat non-ActiveX DLL for Delphi * The examples here use the ActiveX DLL.

uses
    Winapi.Windows, Winapi.Messages, System.SysUtils, System.Variants, System.Classes, Vcl.Graphics,
    Vcl.Controls, Vcl.Forms, Vcl.Dialogs, Vcl.StdCtrls, Chilkat_TLB;

...

procedure TForm1.Button1Click(Sender: TObject);
var
ecc: TChilkatEcc;
fortuna: TChilkatPrng;
entropy: WideString;
success: Integer;
privKey: IPrivateKey;
asn: TChilkatAsn;
xml: TChilkatXml;
crypt: TChilkatCrypt2;
privKeyHex: WideString;

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

ecc := TChilkatEcc.Create(Self);

// 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.
fortuna := TChilkatPrng.Create(Self);
entropy := fortuna.GetEntropy(32,'base64');
success := fortuna.AddEntropy(entropy,'base64');

privKey := ecc.GenEccKey('secp256k1',fortuna.ControlInterface);
if (ecc.LastMethodSuccess <> 1) then
  begin
    Memo1.Lines.Add(ecc.LastErrorText);
    Exit;
  end;

// 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.)

asn := TChilkatAsn.Create(Self);
success := asn.LoadEncoded(privKey.GetPkcs1ENC('base64'),'base64');
if (success <> 1) then
  begin
    Memo1.Lines.Add(asn.LastErrorText);
    Exit;
  end;

xml := TChilkatXml.Create(Self);
xml.LoadXml(asn.AsnToXml());

Memo1.Lines.Add(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.
crypt := TChilkatCrypt2.Create(Self);
privKeyHex := crypt.ReEncode(xml.GetChildContent('octets'),'base64','hex');

Memo1.Lines.Add('EC private key as hex = ' + privKeyHex);
end;