Decrypt S/MIME with an Explicit Certificate and Private Key

See more MIME Examples

Loads a CMS/PKCS #7 encrypted S/MIME message and decrypts it back to the original MIME content.

Decrypt2 accepts the certificate and its private key directly as arguments.

The file paths are relative to the application's current working directory. Absolute paths may also be used. Supply the paths appropriate to your own environment.

program ChilkatDemo;

// Demonstrates using the Chilkat Pascal wrapper via the C bridge DLL.
// Builds as a console application under Lazarus (FPC) or Delphi.

{$IFDEF FPC}
  {$MODE DELPHI}
{$ENDIF}
{$APPTYPE CONSOLE}

uses
  {$IFDEF UNIX}
  cthreads,
  {$ENDIF}
  SysUtils,
  CkDllLoader,
  Chilkat.Mime,
  Chilkat.PrivateKey,
  Chilkat.Cert;

// ---------------------------------------------------------------------------

procedure RunDemo;
var
  success: Boolean;
  mime: TMime;
  cert: TCert;
  privKey: TPrivateKey;
  body: string;

begin
  success := False;

  mime := TMime.Create;
  success := mime.LoadMimeFile('qa_data/encrypted.eml');
  if (success = False) then
    begin
      WriteLn(mime.LastErrorText);
      Exit;
    end;

  //  Decrypt using an explicitly supplied certificate and private key.  The 1st argument is the
  //  certificate and the 2nd is its private key.
  cert := TCert.Create;
  success := cert.LoadFromFile('qa_data/recipient.cer');
  if (success = False) then
    begin
      WriteLn(cert.LastErrorText);
      Exit;
    end;

  privKey := TPrivateKey.Create;
  success := privKey.LoadPemFile('qa_data/recipient_privkey.pem');
  if (success = False) then
    begin
      WriteLn(privKey.LastErrorText);
      Exit;
    end;

  success := mime.Decrypt2(cert,privKey);
  if (success = False) then
    begin
      WriteLn(mime.LastErrorText);
      Exit;
    end;

  body := mime.GetBodyDecoded();
  if (mime.LastMethodSuccess = False) then
    begin
      WriteLn(mime.LastErrorText);
      Exit;
    end;
  WriteLn(body);


  mime.Free;
  cert.Free;
  privKey.Free;

end;

// ---------------------------------------------------------------------------

begin

  try
    RunDemo;
  except
    on E: Exception do
      WriteLn('Unhandled exception: ', E.ClassName, ': ', E.Message);
  end;

  WriteLn;
  {$IFDEF MSWINDOWS}
  WriteLn('Press Enter to exit...');
  ReadLn;
  {$ENDIF}
end.