(Delphi ActiveX) Ed25519 Sign and Verify

Demonstrates how to create an Ed25519 signature, and then to verify it.

Note: This example requires Chilkat v9.5.0.83 or greater.

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
privKeyHex: WideString;
pubKeyHex: WideString;
privKey: TPrivateKey;
success: Integer;
bd: TChilkatBinData;
eddsa: TChilkatEdDSA;
hexSig: WideString;
pubKey: TPublicKey;
bVerified: Integer;

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

privKeyHex := '1498b5467a63dffa2dc9d9e069caf075d16fc33fdd4c3b01bfadae6433767d93';
pubKeyHex := 'b7a3c12dc0c8c748ab07525b701122b88bd78f600c76342d27f25e5f92444cde';

privKey := TPrivateKey.Create(Self);
// This example shows only one way of loading an Ed25519 private key.
// Chilkat can load other formats (JWK, PEM, ASN.1 DER, etc.)  
// You may do so by calling LoadAnyFormat or LoadAnyFormatFile.
success := privKey.LoadEd25519(privKeyHex,pubKeyHex);
if (success = 0) then
  begin
    Memo1.Lines.Add(privKey.LastErrorText);
    Exit;
  end;

// The data to be signed...
bd := TChilkatBinData.Create(Self);
bd.AppendString('Message for Ed25519 signing','utf-8');

eddsa := TChilkatEdDSA.Create(Self);
hexSig := eddsa.SignBdENC(bd.ControlInterface,'hexlower',privKey.ControlInterface);

Memo1.Lines.Add('signature = ' + hexSig);

// The expected output is: 6dd355667fae4eb43c6e0ab92e870edb2de0a88cae12dbd8591507f584fe4912babff497f1b8edf9567d2483d54ddc6459bea7855281b7a246a609e3001a4e08

// Verify the signature..
pubKey := TPublicKey.Create(Self);
success := pubKey.LoadEd25519(pubKeyHex);
if (success = 0) then
  begin
    Memo1.Lines.Add(pubKey.LastErrorText);
    Exit;
  end;

bVerified := eddsa.VerifyBdENC(bd.ControlInterface,hexSig,'hexlower',pubKey.ControlInterface);
if (bVerified = 0) then
  begin
    Memo1.Lines.Add(eddsa.LastErrorText);
    Memo1.Lines.Add('Failed to verify the signature.');
    Exit;
  end;

Memo1.Lines.Add('The Ed25519 signature is verified!');
end;