[PATCH 3/4] SIM/USIM: Add function to get the MNC length from the SIM/USIM

[Jouni Malinen]

On Sun, Jan 15, 2012 at 09:32:47PM +0100, Simon Baatz wrote:
> The EF-AD (administrative data) file may contain information about the
> length of the MNC (2 or 3 digits) in the IMSI. This can be used to
> construct the realm according to 3GPP TS 23.003 during EAP-SIM or
> EAP-AKA authentication.

Thanks, applied. Though, I added a new return value for indicating that
the optional MNC length field was not present in EF_AD to make the debug
output somewhat cleaner.

The first SIM card I tested (prepaid Elisa/Kolumbus) this with happened
to not include the MNC length and the default assumption of 3-digit MNC
in the patch 4/4 was not the correct one for that card.. Unfortunately,
it looks like there would need to be a list of MCC/MNC values with the
MNC length for the automatic detection to work reliably (what a silly
design to make that field optional and not allow automatic way of
figuring out the correct field length).
 
-- 
Jouni Malinen                                            PGP id EFC895FA