Pascal (Lazarus/Delphi)

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.

Pascal (Lazarus/Delphi)

program ChilkatDemo;

// Demonstrates using the Chilkat Pascal wrapper via the C bridge DLL.
// Builds as a console application under Lazarus (FPC) or Delphi.

{$IFDEF FPC}
  {$MODE DELPHI}
{$ENDIF}
{$APPTYPE CONSOLE}

uses
  {$IFDEF UNIX}
  cthreads,
  {$ENDIF}
  SysUtils,
  CkDllLoader,
  Chilkat.Cert,
  Chilkat.Crypt2;

// ---------------------------------------------------------------------------

procedure RunDemo;
var
  success: Boolean;
  crypt: TCrypt2;
  cert1: TCert;
  cert2: TCert;
  inFile: string;
  p7sFile: string;
  extractedToFilePath: string;

begin
  success := False;

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

  crypt := TCrypt2.Create;

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

  cert1 := TCert.Create;
  success := cert1.LoadPfxFile('qa_data/pfx/cert_test123.pfx','test123');
  if (success <> True) then
    begin
      WriteLn(cert1.LastErrorText);
      Exit;
    end;

  cert2 := TCert.Create;
  success := cert2.LoadPfxFile('qa_data/pfx/test_secret.pfx','secret');
  if (success <> True) then
    begin
      WriteLn(cert2.LastErrorText);
      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 := crypt.AddSigningCert(cert1);
  if (success <> True) then
    begin
      WriteLn(crypt.LastErrorText);
      Exit;
    end;
  success := crypt.AddSigningCert(cert2);
  if (success <> True) then
    begin
      WriteLn(crypt.LastErrorText);
      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. 
  crypt.CadesEnabled := True;

  crypt.HashAlgorithm := '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 := crypt.CreateP7M(inFile,p7sFile);
  if (success = False) then
    begin
      WriteLn(crypt.LastErrorText);
      Exit;
    end;

  //  Verify the .p7s file and extract the original file from the .p7s. 
  extractedToFilePath := 'qa_output/sample.pdf';
  success := crypt.VerifyP7M(p7sFile,extractedToFilePath);
  if (success = False) then
    begin
      WriteLn(crypt.LastErrorText);
      Exit;
    end;

  WriteLn('Success!');


  crypt.Free;
  cert1.Free;
  cert2.Free;

end;

// ---------------------------------------------------------------------------

begin

  try
    RunDemo;
  except
    on E: Exception do
      WriteLn('Unhandled exception: ', E.ClassName, ': ', E.Message);
  end;

  WriteLn;
  {$IFDEF MSWINDOWS}
  WriteLn('Press Enter to exit...');
  ReadLn;
  {$ENDIF}
end.