Pascal (Lazarus/Delphi)

S/MIME Encrypt .eml without Sending

See more Email Object Examples

Demonstrates how to encrypt an email using the recipient's digital certificate. This example just encrypts, and does not send the email. Pascal (Lazarus/Delphi)

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.MailMan,
  Chilkat.StringBuilder,
  Chilkat.Cert,
  Chilkat.Email;

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

procedure RunDemo;
var
  success: Boolean;
  email: TEmail;
  cert: TCert;
  sbSmime: TStringBuilder;
  mailman: TMailMan;

begin
  success := False;

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

  email := TEmail.Create;

  success := email.LoadEml('c:/temp/email/unencrypted.eml');
  if (success = False) then
    begin
      WriteLn(email.LastErrorText);
      Exit;
    end;

  //  The email content is encrypted using AES with a 256-bit key, operating in GCM mode, which provides authenticated encryption.
  email.Pkcs7CryptAlg := 'aes-gcm';
  email.Pkcs7KeyLength := 256;
  email.OaepPadding := True;
  email.OaepHash := 'sha256';
  email.OaepMgfHash := 'sha256';

  cert := TCert.Create;
  success := cert.LoadFromFile('c/temps/cert/recipient.cer');
  if (success = False) then
    begin
      WriteLn(cert.LastErrorText);
      Exit;
    end;

  email.SendEncrypted := True;
  email.SetEncryptCert(cert);

  sbSmime := TStringBuilder.Create;

  //  The mailman object applies the encryption by rendering the email according to the instructions (property settings) provided in the email object.
  //  No email is sent.
  mailman := TMailMan.Create;
  success := mailman.RenderToMimeSb(email,sbSmime);
  if (success = False) then
    begin
      WriteLn(mailman.LastErrorText);
      Exit;
    end;

  success := sbSmime.WriteFile('c:/temp/encryptedEmail.eml','utf-8',False);
  if (success = False) then
    begin
      WriteLn(mailman.LastErrorText);
      Exit;
    end;

  WriteLn('Success!');


  email.Free;
  cert.Free;
  sbSmime.Free;
  mailman.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.