[erlang-questions] Pure Ruby to Erlang node handshake problem

[Dave Bryson]

I'm creating a pure ruby 'node' that can talk to an Erlang node  
similar to what the jinterface provides.  So far I have most of the  
initial
handshake working properly but am getting the following error from the  
Erlang side when I send the challenge reply:

* Connection attempt from disallowed node 'ruby_client@REDACTED' **

(note: I manually set the cookie on both sides)

Here are the handshake steps I'm taking:

1. Send Name information
2. Receive status
3. Receive challenge
4. Send challenge

Everything up to 4 is working fine and the data received from the  
Erlang node seems to be correct (I'm parsing it correctly)

I'm sending the challenge reply like this:

content = erlang_node_challenge concatenated with my_cookie
digest = MD5.hexdigest(content)
my_challenge = randomly generated number

With the outbound message in this format:

Bytes   |  Message
   2        |   21       (length of the message)
   1        |   'r'       (tag)
   4        |   my_challenge
   16      |   digest


This seems to be correct according to the distributed handshake docs  
and the code in jinterface.

Any ideas why the Erlang node is rejecting my challenge reply?

Note: I'm using 12b-5

Thanks!
Dave