asterisk users - Mar 2004 - make asterisk ignore password in sip register

I am looking for a way to set my * so that it'll accept REGISTERs with a
particular username, regardless of the password used. Snooping the network
traffic suggests that the password is sent in digest or some other
non-plaintext format, so I don't suppose there is an easy way for me to
find out what password is being sent. As a workaround, I thought maybe I
could tell * to accept the registration regardless of the actual password
used. Unfortunately, I can't get google to tell me the answer, and
voip-info.org apparently isn't accepting my connections.

I tried just leaving out the secret= line from that section in sip.conf,
and also tried secret= with nothing on the right-hand side. Either way, I
get a Registration failed message on the * console.

Greg