Delphi DLL

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 Delphi DLL

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

...

procedure TForm1.Button1Click(Sender: TObject);
var
success: Boolean;
pdf: HCkPdf;
sigInfo: HCkJsonObject;
numSignatures: Integer;
validated: Boolean;
cert: HCkCert;
i: Integer;

begin
success := False;

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

pdf := CkPdf_Create();

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

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

// Iterate over each signature and validate each.
numSignatures := CkPdf_getNumSignatures(pdf);
validated := False;
cert := CkCert_Create();
i := 0;
while i < numSignatures do
  begin
    validated := CkPdf_VerifySignature(pdf,i,sigInfo);
    Memo1.Lines.Add('Signature ' + IntToStr(i) + ' validated: ' + IntToStr(Ord(validated)));

    // After calling VerifySignature, you can get the signer certificate by calling
    // GetSignerCert with the same index. 
    success := CkPdf_GetSignerCert(pdf,i,cert);
    if (success <> False) then
      begin
        Memo1.Lines.Add('PDF signer certificate: ' + CkCert__subjectDN(cert));
      end;

    i := i + 1;
  end;

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

CkPdf_Dispose(pdf);
CkJsonObject_Dispose(sigInfo);
CkCert_Dispose(cert);

end;