(Delphi ActiveX) RSA Signature with Certificate's Private Key from PFX

See more RSA Examples

Demonstrates how to use a certificate's private key from a PFX file to create an RSA signature.

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
certStore: TChilkatCertStore;
success: Integer;
cert: IChilkatCert;
pkey: IPrivateKey;
pkeyXml: WideString;
rsa: TChilkatRsa;
strData: WideString;
hexSig: WideString;

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

// Create an instance of a certificate store object, load a PFX file,
// locate the certificate we need, and use it for signing.
// (a PFX file may contain more than one certificate.)
certStore := TChilkatCertStore.Create(Self);

// The 1st argument is the filename, the 2nd arg is the 
// PFX file's password:
success := certStore.LoadPfxFile('chilkat.pfx','test');
if (success <> 1) then
  begin
    Memo1.Lines.Add(certStore.LastErrorText);
    Exit;
  end;

cert := certStore.FindCertBySubject('Chilkat Software, Inc.');
if (certStore.LastMethodSuccess = 0) then
  begin
    Memo1.Lines.Add(certStore.LastErrorText);
    Exit;
  end;

pkey := cert.ExportPrivateKey();
if (cert.LastMethodSuccess = 0) then
  begin
    Memo1.Lines.Add(cert.LastErrorText);

    Exit;
  end;

// Get the private key in XML format:
pkeyXml := pkey.GetXml();

rsa := TChilkatRsa.Create(Self);

// Import the private key into the RSA component:
success := rsa.ImportPrivateKey(pkeyXml);
if (success <> 1) then
  begin
    Memo1.Lines.Add(rsa.LastErrorText);

    Exit;
  end;

// Encode the signature as a hex string
rsa.EncodingMode := 'hex';

strData := 'This is the string to be signed.';

// Sign the string using the sha-1 hash algorithm.
// Other valid choices are "sha-256", "md2" and "md5".
hexSig := rsa.SignStringENC(strData,'sha-1');

Memo1.Lines.Add(hexSig);

Memo1.Lines.Add('Success!');
end;