Delphi DLL

CoSign PKCS7/CMS Signed Data

See more Digital Signatures Examples

Demonstrates how to add a 2nd signature to a CMS SignedData. This is to add an additional signature, SignerInfo and certificate(s) to an existing CMS signed data.

In this example, we cosign an existing pdf.p7s

Note: The CoSign method is added in Chilkat v9.5.0.89.

Delphi DLL

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

...

procedure TForm1.Button1Click(Sender: TObject);
var
success: Boolean;
crypt: HCkCrypt2;
cert: HCkCert;
bd: HCkBinData;
bd2: HCkBinData;

begin
success := False;

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

crypt := CkCrypt2_Create();
cert := CkCert_Create();

// If loading from a smart card, set the smartcard PIN.
CkCert_putSmartCardPin(cert,'0000');

// Load a certificate in some way, such as from a smart card.
// Chilkat provides other methods to load from a .pfx, .pem, or from the Windows certificate stores..
success := CkCert_LoadFromSmartcard(cert,'');
if (success = False) then
  begin
    Memo1.Lines.Add(CkCert__lastErrorText(cert));
    Exit;
  end;

success := CkCrypt2_SetSigningCert(crypt,cert);
if (success = False) then
  begin
    Memo1.Lines.Add(CkCrypt2__lastErrorText(crypt));
    Exit;
  end;

// Load the file to be co-signed.
// NOTE:  This is to cosign a PDF file contained within a CMS (PKCS7) message.
// (In other words, the PDF is contained within the CMS SignedData, rather than the other way around
// where a CMS signature is contained within a PDF.  Use Chilkat's PDF class to sign a PDF, which is
// to embed a CMS signature within the PDF.)
bd := CkBinData_Create();
success := CkBinData_LoadFile(bd,'qa_data/p7s/cosign/sample.pdf.p7s');
if (success = False) then
  begin
    Memo1.Lines.Add('Failed to load pdf.p7s input file.');
    Exit;
  end;

// bd2 will contain the co-signed result.
bd2 := CkBinData_Create();
success := CkCrypt2_CoSign(crypt,bd,cert,bd2);
if (success = False) then
  begin
    Memo1.Lines.Add(CkCrypt2__lastErrorText(crypt));
    Exit;
  end;

success := CkBinData_WriteFile(bd,'qa_output/cosigned.pdf.p7s');
if (success = False) then
  begin
    Memo1.Lines.Add('Failed to save pdf.p7s output file.');
    Exit;
  end;

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

CkCrypt2_Dispose(crypt);
CkCert_Dispose(cert);
CkBinData_Dispose(bd);
CkBinData_Dispose(bd2);

end;