Authentication and key Agreement

[Wally Ritchie]

On Nov 27, 2007 8:49 AM, Xie Xiaolei <xie.xiaolei at acm.org> wrote:
> Hello guys, I am doing a master thesis and experimenting a new AKA
> (Authentication and Key Agreement) protocol on OpenMoko. Could you please
> tell me which part of the gsmd code I should look at?
>
> I understand that, according to the current 3GPP AKA protocol, the phone
> will first request the IMSI or TMSI from the SIM and then ask the SIM to
> produce the expected response after receiving a random number.
>
> However, I find that the only text in the code that contains "IMSI" or
> "TMSI" is GSMD_PHONEBOOK_GET_IMSI.
>
> Any hint is appreciated. Thanks!
>
The AT+CSIM command which would allow this to be done is currently disabled
in the GSM Modem Firmware. You can only perform a restricted set of SIM
operations using the AT+CRSM command and these are limited to file access.

Authentication requires doing a RUN GSM ALGORITHM command which is not
presently accessible and is only done internally by the chipset.

This is supposedly for "security reasons" but personally, I don't see
any real security
issues here. In any case its not available.

Cheers
> --
> Xie Xiaolei
> Address: Jämeräntaival 11 E 114, Otaniemi, 02150 Espoo, Finland
> GSM: +358 40 0356 539