(Delphi ActiveX) Sign JSON to Create CAdES P7S Bytes

Demonstrates how to sign JSON using a certificate + private key from a .p12/.pfx to create a CAdES P7S byte array.

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
crypt: TChilkatCrypt2;
cert: TChilkatCert;
success: Integer;
jsonSigningAttrs: TChilkatJsonObject;
cadesP7s: Array of Byte;
originalJson: WideString;

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

crypt := TChilkatCrypt2.Create(Self);

cert := TChilkatCert.Create(Self);
success := cert.LoadPfxFile('qa_data/pfx/cert_test123.pfx','test123');
if (success <> 1) then
  begin
    Memo1.Lines.Add(cert.LastErrorText);
    Exit;
  end;

// Tell the crypt component to use this cert.
success := crypt.SetSigningCert(cert.ControlInterface);
if (success <> 1) then
  begin
    Memo1.Lines.Add(crypt.LastErrorText);
    Exit;
  end;

// The CadesEnabled property applies to all methods that create PKCS7 signatures. 
// To create a CAdES-BES signature, set this property equal to true. 
crypt.CadesEnabled := 1;

crypt.HashAlgorithm := 'sha256';

jsonSigningAttrs := TChilkatJsonObject.Create(Self);
jsonSigningAttrs.UpdateInt('contentType',1);
jsonSigningAttrs.UpdateInt('signingTime',1);
jsonSigningAttrs.UpdateInt('messageDigest',1);
jsonSigningAttrs.UpdateInt('signingCertificateV2',1);
crypt.SigningAttributes := jsonSigningAttrs.Emit();

// By default, all the certs in the chain of authentication are included in the signature.
// If desired, we can choose to only include the signing certificate:
crypt.IncludeCertChain := 0;

// Create the CAdES-BES attached signature, which contains the original data.
crypt.Charset := 'utf-8';

cadesP7s := crypt.OpaqueSignString('{ "abc": 123}');
if (crypt.LastMethodSuccess = 0) then
  begin
    Memo1.Lines.Add(crypt.LastErrorText);
    Exit;
  end;

// Verify the signature and extract the original JSON:
originalJson := crypt.OpaqueVerifyString(cadesP7s);
if (crypt.LastMethodSuccess = 0) then
  begin
    Memo1.Lines.Add(crypt.LastErrorText);
    Exit;
  end;

Memo1.Lines.Add('Original JSON: ' + originalJson);

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