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

Delphi DLL 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.

Chilkat for Delphi Downloads Chilkat non-ActiveX DLL for Delphi Chilkat ActiveX DLL for Delphi * The examples here use the non-ActiveX DLL.

uses
    Winapi.Windows, Winapi.Messages, System.SysUtils, System.Variants, System.Classes, Vcl.Graphics,
    Vcl.Controls, Vcl.Forms, Vcl.Dialogs, Vcl.StdCtrls, Cert, CertStore, Crypt2;

...

procedure TForm1.Button1Click(Sender: TObject);
var
crypt: HCkCrypt2;
signingCertSubject: PWideChar;
pfxFilename: PWideChar;
pfxPassword: PWideChar;
certStore: HCkCertStore;
success: Boolean;
cert: HCkCert;
inFile: PWideChar;
sigFile: PWideChar;

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

crypt := CkCrypt2_Create();

// 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 := CkCertStore_Create();
success := CkCertStore_LoadPfxFile(certStore,pfxFilename,pfxPassword);
if (success <> True) then
  begin
    Memo1.Lines.Add(CkCertStore__lastErrorText(certStore));
    Exit;
  end;

cert := CkCertStore_FindCertBySubjectCN(certStore,signingCertSubject);
if (CkCertStore_getLastMethodSuccess(certStore) = False) then
  begin
    Memo1.Lines.Add('Failed to find certificate by subject common name.');
    Exit;
  end;

// Tell the crypt component to use this cert.
success := CkCrypt2_SetSigningCert(crypt,cert);

// 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 := CkCrypt2_CreateP7S(crypt,inFile,sigFile);
if (success = False) then
  begin
    Memo1.Lines.Add(CkCrypt2__lastErrorText(crypt));
    CkCert_Dispose(cert);
    Exit;
  end;

success := CkCrypt2_VerifyP7S(crypt,inFile,sigFile);
if (success = False) then
  begin
    Memo1.Lines.Add(CkCrypt2__lastErrorText(crypt));
    CkCert_Dispose(cert);
    Exit;
  end;

CkCert_Dispose(cert);

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

CkCrypt2_Dispose(crypt);
CkCertStore_Dispose(certStore);

end;