my $ldap = Net::LDAP->new( 'myhost.example.com', version => 3 );
my $mesg = $ldap->start_tls(
                           verify => 'require',
                           clientcert => 'mycert.pem',
                           clientkey => 'mykey.pem',
                           decryptkey => sub { 'secret'; },
                           capath => '/usr/local/cacerts/'
                         );