(Delphi DLL) 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 non-ActiveX DLL for Delphi Chilkat ActiveX DLL for Delphi * The examples here use the non-ActiveX DLL.

uses
    Winapi.Windows, Winapi.Messages, System.SysUtils, System.Variants, System.Classes, Vcl.Graphics,
    Vcl.Controls, Vcl.Forms, Vcl.Dialogs, Vcl.StdCtrls, CkByteData, Cert, JsonObject, Crypt2;

...

procedure TForm1.Button1Click(Sender: TObject);
var
crypt: HCkCrypt2;
cert: HCkCert;
success: Boolean;
jsonSigningAttrs: HCkJsonObject;
cadesP7s: HCkByteData;
originalJson: PWideChar;

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

crypt := CkCrypt2_Create();

cert := CkCert_Create();
success := CkCert_LoadPfxFile(cert,'qa_data/pfx/cert_test123.pfx','test123');
if (success <> True) then
  begin
    Memo1.Lines.Add(CkCert__lastErrorText(cert));
    Exit;
  end;

// Tell the crypt component to use this cert.
success := CkCrypt2_SetSigningCert(crypt,cert);
if (success <> True) then
  begin
    Memo1.Lines.Add(CkCrypt2__lastErrorText(crypt));
    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. 
CkCrypt2_putCadesEnabled(crypt,True);

CkCrypt2_putHashAlgorithm(crypt,'sha256');

jsonSigningAttrs := CkJsonObject_Create();
CkJsonObject_UpdateInt(jsonSigningAttrs,'contentType',1);
CkJsonObject_UpdateInt(jsonSigningAttrs,'signingTime',1);
CkJsonObject_UpdateInt(jsonSigningAttrs,'messageDigest',1);
CkJsonObject_UpdateInt(jsonSigningAttrs,'signingCertificateV2',1);
CkCrypt2_putSigningAttributes(crypt,CkJsonObject__emit(jsonSigningAttrs));

// 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:
CkCrypt2_putIncludeCertChain(crypt,False);

// Create the CAdES-BES attached signature, which contains the original data.
CkCrypt2_putCharset(crypt,'utf-8');
cadesP7s := CkByteData_Create();
success := CkCrypt2_OpaqueSignString(crypt,'{ "abc": 123}',cadesP7s);
if (CkCrypt2_getLastMethodSuccess(crypt) = False) then
  begin
    Memo1.Lines.Add(CkCrypt2__lastErrorText(crypt));
    Exit;
  end;

// Verify the signature and extract the original JSON:
originalJson := CkCrypt2__opaqueVerifyString(crypt,cadesP7s);
if (CkCrypt2_getLastMethodSuccess(crypt) = False) then
  begin
    Memo1.Lines.Add(CkCrypt2__lastErrorText(crypt));
    Exit;
  end;

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

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

CkCrypt2_Dispose(crypt);
CkCert_Dispose(cert);
CkJsonObject_Dispose(jsonSigningAttrs);
CkByteData_Dispose(cadesP7s);

end;