(Delphi ActiveX) RSA Sign using Base64 Private Key

Signs a string using a non-encrypted RSA private key in base64 encoding. Returns the RSA signature as a base64 string.

Note: This example requires Chilkat v11.0.0 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
success: Integer;
privKey: TPrivateKey;
sbPem: TChilkatStringBuilder;
rsa: TChilkatRsa;
bd: TChilkatBinData;
strOriginal: WideString;

begin
success := 0;

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

privKey := TPrivateKey.Create(Self);

sbPem := TChilkatStringBuilder.Create(Self);
sbPem.AppendLine('-----BEGIN RSA PRIVATE KEY-----',1);
sbPem.AppendLine('MIIC .... j5A==',1);
sbPem.AppendLine('-----END RSA PRIVATE KEY-----',1);

success := privKey.LoadPem(sbPem.GetAsString());
if (success = 0) then
  begin
    Memo1.Lines.Add(privKey.LastErrorText);
    Exit;
  end;

rsa := TChilkatRsa.Create(Self);

success := rsa.UsePrivateKey(privKey.ControlInterface);
if (success = 0) then
  begin
    Memo1.Lines.Add(rsa.LastErrorText);
    Exit;
  end;

bd := TChilkatBinData.Create(Self);
bd.AppendString('12345678','utf-8');

success := rsa.SignRawBd(bd.ControlInterface);
if (success = 0) then
  begin
    Memo1.Lines.Add(rsa.LastErrorText);
    Exit;
  end;

// Get the base64 RSA signature.
Memo1.Lines.Add(bd.GetEncoded('base64'));

success := rsa.VerifyRawBd(bd.ControlInterface);
if (success = 0) then
  begin
    Memo1.Lines.Add(rsa.LastErrorText);
    Exit;
  end;

strOriginal := bd.GetString('utf-8');
Memo1.Lines.Add(strOriginal);
end;