MIME S/MIME Encryption Algorithm Properties

See more MIME Examples

Demonstrates the properties that control S/MIME encryption: Pkcs7CryptAlg (the symmetric content-encryption algorithm), Pkcs7KeyLength (the content-encryption key length in bits), OaepPadding (whether RSAES-OAEP key transport is used instead of RSAES-PKCS1-v1_5), and the OAEP hash settings OaepHash and OaepMgfHash. The properties are configured before calling Encrypt.

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.Cert,
  Chilkat.Mime;

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

procedure RunDemo;
var
  success: Boolean;
  mime: TMime;
  cert: TCert;

begin
  success := False;

  mime := TMime.Create;
  success := mime.SetBodyFromPlainText('This message will be encrypted.');
  if (success = False) then
    begin
      WriteLn(mime.LastErrorText);
      Exit;
    end;

  //  Pkcs7CryptAlg is the symmetric content-encryption algorithm.  Supported values are aes, aes-gcm,
  //  des, 3des, and rc2.  The default is aes.
  mime.Pkcs7CryptAlg := 'aes';

  //  Pkcs7KeyLength is the content-encryption key length in bits.  The default is 128.
  mime.Pkcs7KeyLength := 256;

  //  OaepPadding selects the RSA key-transport padding.  The default is False (RSAES-PKCS1-v1_5).
  //  Set True to use RSAES-OAEP, in which case the OAEP hash settings apply.
  mime.OaepPadding := True;
  mime.OaepHash := 'sha256';
  mime.OaepMgfHash := 'sha256';

  //  Load the recipient certificate (public key is sufficient for encrypting).
  cert := TCert.Create;
  success := cert.LoadFromFile('qa_data/recipient.cer');
  if (success = False) then
    begin
      WriteLn(cert.LastErrorText);
      Exit;
    end;

  //  Encrypt using the algorithm settings configured above.
  success := mime.Encrypt(cert);
  if (success = False) then
    begin
      WriteLn(mime.LastErrorText);
      Exit;
    end;

  WriteLn('Encrypted with ' + mime.Pkcs7CryptAlg + ' ' + mime.Pkcs7KeyLength + '-bit key.');


  mime.Free;
  cert.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.