Aastra phones - HTTP auto provisioning

Hi everyone,

I started playing with FusionPBX last month but since then, I've been struggling to auto provision my aastra phones using HTTP provisioning.
I mostly followed the steps from:

Looking at the logs, by changing the http path on the phone, I would get different http erros.
/app/provision would give me 401.
leaving it blank would give me 301.

After many trial and error attempts, I finally got 200, with all files (technically) loaded. But in the phone logs (server.cfg) I would see "Invalid mac address"
For this specific attempt, I used this http path:
/app/provision/index.php?mac=$1 last

I also added the rewrite rules described on the wiki page (although it was already set on my fusionpbx files).
*provision has been enabled, as well as http user/password auth (although I am not quite sure where to put it on the phones - I guess sip global config, that is where I placed it).

TFTP provisioning is working good but I guess fusionpbx brings a lot of benefit with HTTP provisioning.
Any help will be greatly appreciated

Thank you!