Delphi ActiveX

Ed25519ph Sign and Verify

See more Ed25519 Examples

Demonstrates how to create an Ed25519ph signature, and then to verify it.

Note: This example requires Chilkat v9.5.0.91 or greater.

Delphi ActiveX

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

begin
success := 0;

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

// Use the following test vector from https://www.rfc-editor.org/rfc/rfc8032#page-30

//    -----TEST abc
// 
//    ALGORITHM:
//    Ed25519ph
// 
//    SECRET KEY:
//    833fe62409237b9d62ec77587520911e
//    9a759cec1d19755b7da901b96dca3d42
// 
//    PUBLIC KEY:
//    ec172b93ad5e563bf4932c70e1245034
//    c35467ef2efd4d64ebf819683467e2bf
// 
//    MESSAGE (length 3 bytes):
//    616263
// 
//    SIGNATURE:
//    98a70222f0b8121aa9d30f813d683f80
//    9e462b469c7ff87639499bb94e6dae41
//    31f85042463c2a355a2003d062adf5aa
//    a10b8c61e636062aaad11c2a26083406

privKeyHex := '833fe62409237b9d62ec77587520911e9a759cec1d19755b7da901b96dca3d42';
pubKeyHex := 'ec172b93ad5e563bf4932c70e1245034c35467ef2efd4d64ebf819683467e2bf';

privKey := TPrivateKey.Create(Self);
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.AppendEncoded('616263','hex');

eddsa := TChilkatEdDSA.Create(Self);
// Indicate we want the Ed25519ph instance.
eddsa.Algorithm := 'Ed25519ph';

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

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

// The expected output is: 98a70222f0b8121aa9d30f813d683f80....

// 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 Ed25519ph signature is verified!');
end;