(Delphi ActiveX) Sign a File to Create a .p7s (Detached Signature)

Delphi ActiveX example to create a detached signature file (.p7s) for any type file. The signature can be verified by calling VerifyP7S and passing the original filename and the .p7s filename.

Note: This example requires Chilkat v10.1.2 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
crypt: TChilkatCrypt2;
signingCertSubject: WideString;
pfxFilename: WideString;
pfxPassword: WideString;
certStore: TChilkatCertStore;
success: Integer;
jsonCN: TChilkatJsonObject;
cert: TChilkatCert;
inFile: WideString;
sigFile: WideString;

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

crypt := TChilkatCrypt2.Create(Self);

// Use a digital certificate and private key from a PFX file (.pfx or .p12).
signingCertSubject := 'Acme Inc';
pfxFilename := '/Users/chilkat/testData/pfx/acme.pfx';
pfxPassword := 'test123';

certStore := TChilkatCertStore.Create(Self);
success := certStore.LoadPfxFile(pfxFilename,pfxPassword);
if (success <> 1) then
  begin
    Memo1.Lines.Add(certStore.LastErrorText);
    Exit;
  end;

jsonCN := TChilkatJsonObject.Create(Self);
jsonCN.UpdateString('CN',signingCertSubject);

cert := TChilkatCert.Create(Self);
success := certStore.FindCert(jsonCN.ControlInterface,cert.ControlInterface);
if (success = 0) then
  begin
    Memo1.Lines.Add('Failed to find certificate by subject common name.');
    Exit;
  end;

// Tell the crypt component to use this cert.
success := crypt.SetSigningCert(cert.ControlInterface);

// We can sign any type of file, creating a .p7s as output:
inFile := '/Users/chilkat/testData/pdf/sample.pdf';
sigFile := '/Users/chilkat/testData/p7s/sample.p7s';

success := crypt.CreateP7S(inFile,sigFile);
if (success = 0) then
  begin
    Memo1.Lines.Add(crypt.LastErrorText);
    Exit;
  end;

success := crypt.VerifyP7S(inFile,sigFile);
if (success = 0) then
  begin
    Memo1.Lines.Add(crypt.LastErrorText);
    Exit;
  end;

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