I am setting up a connection to a database of users, whose passwords have been saved as a one-way hash.

That means that my xml_curl php/sql will need to perform the authentication, and return a user without any password.
(According to Anthony, back in 2008: http://lists.freeswitch.org/pipermail/freeswitch-users/2008-February/029882.html )

Only thing is I can't find any mention anywhere of how to re-generate the user's password from the sip_auth variables in order to run it through my one-way hash for comparison to the database.

It's got to be something to do with these:

sip_auth_nonce = 4d95dd9f-2247-474a-8496-aa7c08700fe7  
sip_auth_cnonce = a088c6b6ba18d1387a45998b6bfa842d
sip_auth_nc = 0000000a
sip_auth_response = 9edefab216a46ed75f1ed1297dd9c9d3  

Any ideas how to rebuild the original user's password?

Or is there a way to send the password through as part of the post? (maybe using enable-post-var)

Cheers,
Fraser