(Delphi ActiveX) Get Certificates within XML Signature

Demonstrates how to get the certificates contained within an XML signature.

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
sbXml: TChilkatStringBuilder;
success: Integer;
dsig: TChilkatXmlDSig;
i: Integer;
saCerts: TCkStringArray;
cert: TChilkatCert;
bVerifyReferenceDigests: Integer;
bVerified: Integer;
j: Integer;

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

sbXml := TChilkatStringBuilder.Create(Self);

// Load XML containing one or more signatures.
success := sbXml.LoadFile('qa_data/xml_dsig_valid_samples/multipleSigners/sp.pdf.XAdES.xml','utf-8');
if (success = 0) then
  begin
    Memo1.Lines.Add('Failed to load the XML file..');
    Exit;
  end;

dsig := TChilkatXmlDSig.Create(Self);

// First load the XML containing the signatures to be verified.
// Note that this particular Signature already contains the RSA public key that will be used
// for verification.
success := dsig.LoadSignatureSb(sbXml.ControlInterface);
if (success <> 1) then
  begin
    Memo1.Lines.Add(dsig.LastErrorText);
    Exit;
  end;

// For each signature, verify and also get the certificate(s) contained within each Signature.
i := 0;
saCerts := TCkStringArray.Create(Self);
cert := TChilkatCert.Create(Self);

Memo1.Lines.Add('numSignatures = ' + IntToStr(dsig.NumSignatures));

while i < dsig.NumSignatures do
  begin
    // Select the Nth signature by setting the Selector property.
    dsig.Selector := i;

    bVerifyReferenceDigests := 1;
    bVerified := dsig.VerifySignature(bVerifyReferenceDigests);
    Memo1.Lines.Add('Signature ' + IntToStr(i + 1) + ' verified = ' + IntToStr(Ord(bVerified)));

    // Get the certificates embedded in this signature.
    saCerts.Clear();
    success := dsig.GetCerts(saCerts.ControlInterface);
    if (success = 1) then
      begin
        j := 0;
        while j < saCerts.Count do
          begin
            success := cert.LoadFromBase64(saCerts.GetString(j));
            if (success = 1) then
              begin
                Memo1.Lines.Add('    ' + cert.SubjectDN);
              end;
            j := j + 1;
          end;

      end;

    i := i + 1;
  end;
end;