Delphi DLL

Create CMS Signed File (PDF) with Multiple Signing Certificates

See more Digital Signatures Examples

Demonstrates how to sign a file by adding multiple signatures (multiple certificates). This example signs a PDF file to produce an output file that is a CMS signature wrapping the original PDF. (Note: This is different than modifying a PDF by injecting a signature into the PDF file format.)

Note: This example requires Chilkat v9.5.0.83 or greater.

Delphi DLL

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

...

procedure TForm1.Button1Click(Sender: TObject);
var
success: Boolean;
crypt: HCkCrypt2;
cert1: HCkCert;
cert2: HCkCert;
inFile: PWideChar;
p7sFile: PWideChar;
extractedToFilePath: PWideChar;

begin
success := False;

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

crypt := CkCrypt2_Create();

// ------------ This example requires Chilkat v9.5.0.83 or greater.

cert1 := CkCert_Create();
success := CkCert_LoadPfxFile(cert1,'qa_data/pfx/cert_test123.pfx','test123');
if (success <> True) then
  begin
    Memo1.Lines.Add(CkCert__lastErrorText(cert1));
    Exit;
  end;

cert2 := CkCert_Create();
success := CkCert_LoadPfxFile(cert2,'qa_data/pfx/test_secret.pfx','secret');
if (success <> True) then
  begin
    Memo1.Lines.Add(CkCert__lastErrorText(cert2));
    Exit;
  end;

// ------------ This example requires Chilkat v9.5.0.83 or greater.

// Tell the crypt component to use both certificates for signing. 
// When we create the signature, it will be signed by both certificates.
success := CkCrypt2_AddSigningCert(crypt,cert1);
if (success <> True) then
  begin
    Memo1.Lines.Add(CkCrypt2__lastErrorText(crypt));
    Exit;
  end;
success := CkCrypt2_AddSigningCert(crypt,cert2);
if (success <> True) then
  begin
    Memo1.Lines.Add(CkCrypt2__lastErrorText(crypt));
    Exit;
  end;

// The CadesEnabled property applies to all methods that create PKCS7 signatures. 
// To create a CAdES-BES signature, set this property equal to true. 
CkCrypt2_putCadesEnabled(crypt,True);

CkCrypt2_putHashAlgorithm(crypt,'sha256');

// We can sign any type of file, creating a .p7s as output.
// The .p7s contains the signature and also embeds the data of the file that is signed.
inFile := 'qa_data/pdf/sample.pdf';
p7sFile := 'qa_output/sample.pdf.p7s';

// Create the CAdES-BES attached signature, which contains the original data.
// Note: Chilkat's function naming is not accurate.  CreateP7M creates a PKCS7 signature where the signed file
// is contained within the signature.  CreateP7S creates a detached PKCS7 signature where the signed file
// is NOT contained within the signature.  We want the data to be contained in the signature, therefore
// we call CreateP7M even though we are naming our output file .p7s.
success := CkCrypt2_CreateP7M(crypt,inFile,p7sFile);
if (success = False) then
  begin
    Memo1.Lines.Add(CkCrypt2__lastErrorText(crypt));
    Exit;
  end;

// Verify the .p7s file and extract the original file from the .p7s. 
extractedToFilePath := 'qa_output/sample.pdf';
success := CkCrypt2_VerifyP7M(crypt,p7sFile,extractedToFilePath);
if (success = False) then
  begin
    Memo1.Lines.Add(CkCrypt2__lastErrorText(crypt));
    Exit;
  end;

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

CkCrypt2_Dispose(crypt);
CkCert_Dispose(cert1);
CkCert_Dispose(cert2);

end;