(Delphi ActiveX) Verify XML Digital Signature

Verifies XML signatures in an XML file.

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;
bVerifyReferenceDigests: Integer;
bVerified: Integer;

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

sbXml := TChilkatStringBuilder.Create(Self);
success := sbXml.LoadFile('qa_data/xml_dsig_verify/csioz_sample.xml','utf-8');
if (success <> 1) then
  begin
    Memo1.Lines.Add('Failed to load XML file.');
    Exit;
  end;

dsig := TChilkatXmlDSig.Create(Self);

// First load the XML containing the signatures to be verified.
success := dsig.LoadSignatureSb(sbXml.ControlInterface);
if (success <> 1) then
  begin
    Memo1.Lines.Add(dsig.LastErrorText);
    Exit;
  end;

// It's possible that an XML document can contain multiple signatures.
// Each can be verified as follows:
i := 0;
while i < dsig.NumSignatures do
  begin
    // Select the Nth signature by setting the Selector property.
    dsig.Selector := i;

    // The bVerifyReferenceDigests argument determines if we want
    // to also verify each reference digest.  If set to 0,
    // then only the SignedInfo part of the Signature is verified.
    bVerifyReferenceDigests := 1;
    bVerified := dsig.VerifySignature(bVerifyReferenceDigests);
    Memo1.Lines.Add('Signature ' + IntToStr(i + 1) + ' verified = ' + IntToStr(Ord(bVerified)));

    i := i + 1;
  end;
end;