Pascal (Lazarus/Delphi)

Generate ECDSA Key and Get Details as XML

See more ECC Examples

Demonstrates how to generate an ECDSA key and gets the parts as XML. Pascal (Lazarus/Delphi)

program ChilkatDemo;

// Demonstrates using the Chilkat Pascal wrapper via the C bridge DLL.
// Builds as a console application under Lazarus (FPC) or Delphi.

{$IFDEF FPC}
  {$MODE DELPHI}
{$ENDIF}
{$APPTYPE CONSOLE}

uses
  {$IFDEF UNIX}
  cthreads,
  {$ENDIF}
  SysUtils,
  CkDllLoader,
  Chilkat.Asn,
  Chilkat.Prng,
  Chilkat.PrivateKey,
  Chilkat.Xml,
  Chilkat.Crypt2,
  Chilkat.Ecc;

// ---------------------------------------------------------------------------

procedure RunDemo;
var
  success: Boolean;
  ecc: TEcc;
  fortuna: TPrng;
  entropy: string;
  privKey: TPrivateKey;
  asn: TAsn;
  xml: TXml;
  crypt: TCrypt2;
  privKeyHex: string;

begin
  success := False;

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

  ecc := TEcc.Create;

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

  privKey := TPrivateKey.Create;
  success := ecc.GenKey('secp256k1',fortuna,privKey);
  if (success = False) then
    begin
      WriteLn(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 := TAsn.Create;
  success := asn.LoadEncoded(privKey.GetPkcs1ENC('base64'),'base64');
  if (success <> True) then
    begin
      WriteLn(asn.LastErrorText);
      Exit;
    end;

  xml := TXml.Create;
  xml.LoadXml(asn.AsnToXml());

  WriteLn(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 := TCrypt2.Create;
  privKeyHex := crypt.ReEncode(xml.GetChildContent('octets'),'base64','hex');

  WriteLn('EC private key as hex = ' + privKeyHex);


  ecc.Free;
  fortuna.Free;
  privKey.Free;
  asn.Free;
  xml.Free;
  crypt.Free;

end;

// ---------------------------------------------------------------------------

begin

  try
    RunDemo;
  except
    on E: Exception do
      WriteLn('Unhandled exception: ', E.ClassName, ': ', E.Message);
  end;

  WriteLn;
  {$IFDEF MSWINDOWS}
  WriteLn('Press Enter to exit...');
  ReadLn;
  {$ENDIF}
end.