use Authen::SASL qw(Perl);

    $sasl = Authen::SASL->new(
        mechanism => 'NTLM',
        callback  => {
          #  user => $username, # just to leave it empty??
          #  pass => $password, ??
        },
    );

    $client = $sasl->client_new(...); #what to set here? 
    $client->client_start;
    $client->client_step('');
    $client->client_step($challenge);