(Delphi ActiveX) Get PDF Signer Certs

See more PDF Signatures Examples

This example demonstrates how to validate the signatures in a PDF and also shows how to get each signature's signer certificate.

Note: This example requires Chilkat v9.5.0.87 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
pdf: TChilkatPdf;
success: Integer;
sigInfo: TChilkatJsonObject;
numSignatures: Integer;
validated: Integer;
cert: TChilkatCert;
i: Integer;

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

pdf := TChilkatPdf.Create(Self);

// Load a PDF that has cryptographic signatures to be validated
success := pdf.LoadFile('qa_data/pdf/sign_testing_1/helloSigned2.pdf');
if (success = 0) then
  begin
    Memo1.Lines.Add(pdf.LastErrorText);
    Exit;
  end;

// Each time we verify a signature, information about the signature is written into
// sigInfo (replacing whatever sigInfo previously contained).
sigInfo := TChilkatJsonObject.Create(Self);

// Iterate over each signature and validate each.
numSignatures := pdf.NumSignatures;
validated := 0;
cert := TChilkatCert.Create(Self);
i := 0;
while i < numSignatures do
  begin
    validated := pdf.VerifySignature(i,sigInfo.ControlInterface);
    Memo1.Lines.Add('Signature ' + IntToStr(i) + ' validated: ' + IntToStr(Ord(validated)));

    // The GetSignerCert method was added in Chilkat v9.5.0.87
    // After calling VerifySignature, you can get the signer certificate by calling
    // GetSignerCert with the same index. 
    success := pdf.GetSignerCert(i,cert.ControlInterface);
    if (success <> 0) then
      begin
        Memo1.Lines.Add('PDF signer certificate: ' + cert.SubjectDN);
      end;

    i := i + 1;
  end;

Memo1.Lines.Add('Finished.');
end;