Delphi ActiveX

Sign a Byte Array to Create an Opaque Signature in a Byte Array

See more Digital Signatures Examples

Signs data contained in a byte array to produce an opaque signature (also in a byte array). An opaque signature is a PKCS7 signature (also known as CAdES) that embeds the signed data. Also shows how to verify the signature and extract the original data. Delphi ActiveX

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
success: Integer;
cert: TChilkatCert;
fac: TCkFileAccess;
fileBytes: Array of Byte;
crypt: TChilkatCrypt2;
sigBytes: Array of Byte;
originalData: Array of Byte;

begin
success := 0;

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

cert := TChilkatCert.Create(Self);
success := cert.LoadPfxFile('qa_data/pfx/cert_test123.pfx','test123');
if (success = 0) then
  begin
    Memo1.Lines.Add(cert.LastErrorText);
    Exit;
  end;

fac := TCkFileAccess.Create(Self);

fileBytes := fac.ReadEntireFile('qa_data/pdf/sample.pdf');
if (fac.LastMethodSuccess <> 1) then
  begin
    Memo1.Lines.Add(fac.LastErrorText);
    Exit;
  end;

crypt := TChilkatCrypt2.Create(Self);

success := crypt.SetSigningCert(cert.ControlInterface);

// We can sign any type of file.

sigBytes := crypt.OpaqueSignBytes(fileBytes);
if (crypt.LastMethodSuccess <> 1) then
  begin
    Memo1.Lines.Add(crypt.LastErrorText);
    Exit;
  end;

success := fac.WriteEntireFile('qa_output/sample.pdf.p7m',sigBytes);
if (fac.LastMethodSuccess <> 1) then
  begin
    Memo1.Lines.Add(fac.LastErrorText);
    Exit;
  end;

// We can verify the opaque signature and extract the original data like this

originalData := crypt.OpaqueVerifyBytes(sigBytes);
if (crypt.LastMethodSuccess <> 1) then
  begin
    Memo1.Lines.Add(crypt.LastErrorText);
    Exit;
  end;

success := fac.WriteEntireFile('qa_output/sample.pdf',originalData);
if (fac.LastMethodSuccess <> 1) then
  begin
    Memo1.Lines.Add(fac.LastErrorText);
    Exit;
  end;

Memo1.Lines.Add('Signature is verified and the original data was extracted.');
end;