# How does AES-CCM work in BitLocker?

I'm studying this white-paper: http://jessekornblum.com/publications/di09.pdf

The author says that using AES-CCM with the external key (highlighted in green at page 9, figure 4) and with the nonce at offset 0x3662B8 (highlighted in red, figure 5) you can decrypt the data at offset 0x3662D4.

I don't understand how AES-CCM works in BitLocker. Can someone please explain it to me?

I have the following doubts:

1. The length of IV should be of 16 bytes, but I have a nonce of 12 bytes.
2. How is the MAC calculated?
-
The octet length of the CCM nonce is not 16 but $15-L$, where $L$ equals the octet length of the counter. –  Henrick Hellström Jul 15 at 7:07
Don't you understand CCM in BitLocker, or don't you understand CCM at all? Explain CCM is a bit broad. –  owlstead Jul 16 at 0:17
I don't understand CCM in BitLocker –  RobotMan Jul 16 at 21:07