The actual dnswalk code makes it very easy to add
TSIG keys for secured DNS. In the file I am proposing,
only 2 lines were changed, one for the getopts to
recognize -n and -k for TSIG name and key_value and
one in doaxfr to actually set the tsig :
$res->tsig($opt_n,$opt_k);
TSIG enabled dnswalk