(Delphi ActiveX) Duplicate openssl dgst -sha256 -sign private.pem -out sha256.sig in.dat

Demonstrates how to duplicate this OpenSSL command:

openssl dgst -sha256 -sign private.pem -out sha256.sig in.dat

1. Creates a SHA256 digest of the contents of the input file
2. Signs the SHA256 digest using the private key.

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
pkey: TPrivateKey;
success: Integer;
rsa: TChilkatRsa;
bdFileData: TChilkatBinData;
bdSig: TChilkatBinData;

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

pkey := TPrivateKey.Create(Self);

// Load the private key from an PEM file:
success := pkey.LoadPemFile('private.pem');
if (success <> 1) then
  begin
    Memo1.Lines.Add(pkey.LastErrorText);
    Exit;
  end;

rsa := TChilkatRsa.Create(Self);

// Import the private key into the RSA component:
success := rsa.ImportPrivateKeyObj(pkey.ControlInterface);
if (success <> 1) then
  begin
    Memo1.Lines.Add(rsa.LastErrorText);
    Exit;
  end;

// OpenSSL uses big-endian.
rsa.LittleEndian := 0;

// Load the file to be signed.
bdFileData := TChilkatBinData.Create(Self);
success := bdFileData.LoadFile('in.dat');

bdSig := TChilkatBinData.Create(Self);
success := rsa.SignBd(bdFileData.ControlInterface,'sha256',bdSig.ControlInterface);
if (success <> 1) then
  begin
    Memo1.Lines.Add(rsa.LastErrorText);
    Exit;
  end;

// Save the binary signature to a file.
success := bdSig.WriteFile('signature.sig');
if (success <> 1) then
  begin
    Memo1.Lines.Add('Failed to write signature.sig.');
    Exit;
  end;

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