(Delphi ActiveX) Extract XML string from a .p7m byte array (e.g. FATTURA ELETTRONICA, ITALY)

Delphi ActiveX example to extract the original XML from a .p7m (Signed-Data PKCS7 Format) provided as a byte array.

One use for this example is to extract the original XML from a Fattura Elettronica .p7m 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
fac: TCkFileAccess;
p7mBytes: Array of Byte;
crypt: TChilkatCrypt2;
originalXml: WideString;

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

fac := TCkFileAccess.Create(Self);

p7mBytes := fac.ReadEntireFile('testData/p7m/fattura_signature.p7m');
if (fac.LastMethodSuccess <> 1) then
  begin
    Memo1.Lines.Add(fac.LastErrorText);
    Exit;
  end;

crypt := TChilkatCrypt2.Create(Self);

originalXml := crypt.OpaqueVerifyString(p7mBytes);
if (crypt.LastMethodSuccess <> 1) then
  begin
    Memo1.Lines.Add(fac.LastErrorText);
    Exit;
  end;

Memo1.Lines.Add('Original XML:');
Memo1.Lines.Add(originalXml);

Memo1.Lines.Add('Success!');
end;