What is the binary data around the plist in a provisioning profile file?

Question

The structure of a .mobileprovision file looks something like this:

<!-- small binary data -->

<?xml version="1.0" encoding="UTF-8"?>
<!-- plist data -->
</plist>

<!-- large binary data -->

I have a few questions around this:

1. What is this binary data?
2. Is it useful?
3. How can I extract the plist from a .mobileprovision file without searching for XML boundaries?

Specifically, I will consider this question as answered (and award the +100 bounty alongwith it) when both Q1 and Q3 above are answered.

Answer 1

I finally got the answer from an answer to another question on SO.

Basically the .mobileprovision file is a CMS encrypted XML file. It can be decoded using security on OS X:

security cms -D -i /path/to/profile.mobileprovision