HTTParty - Proper way to do Digest Authentication?

[Bob C.]

I'm wanting to use HTTParty to login to secure server using digest
authentication. The remote server is responding with a 400 bad Request
"Too few fields for Authenticate Request Header Argument".

Here's my code:

shttp = COLLECTORS::ServiceHTTParty
shttp.digest_auth(vendorUser, vendorPass)
shttp.headers({
'User-Agent' => agent,
'RETS-Version' => version,
'Accept' => '*/*'
})
shttp.debug_output($stdout)
res = shttp.post(vendorURL)
puts res

This code DOES work for most servers I deal with, but not for one
specific server. Is there a way to find out exactly what the server is
complaining about?

Thanks,

--Bob