SIMtrace hardware questions

[Kevin Redon]

Hi,

Excerpts from Stefanos Malliaros's message of Wed Oct 17 20:57:58 +0200 2012:
> Good evening.
> 
> I am interested in your SIMtrace hardware board and i would like to ask 
> a few questions if possible. ( http://bb.osmocom.org/trac/wiki/SIMtrace)
> 
> First of all i am interested in sniffing data between both SIM and USIM. 
> As a result, i would like to ask if your product fully works with these 
> cards and if i will be able to capture all the data between the mobile 
> terminal and the (U)SIM. (eg. usim authentication)

Yes, SIMtrace is capable of sniffing the communication between (U)SIM and mobile.
To be more precise, 2 transmission protocols exist: T=0, and T=1.
T=0 is the default and most common protocol used. It is fully supported by SIMtrace.
If the (U)SIM and phone both support T=1, and the (U)SIM prefers T=1 and the phone follows this preference, or the phone wants to use it (because it's faster), then T=1 can be used.
It is not too different to T=0, but the sniffing and decoding is not implemented in SIMtrace.
The hardware supports it, but not the software (yet). This is still a todo for the moment, but low priority because rarely used.
Also there have been some corner cases concerning T=0 with high or curious data rates. This lead to faulty decoding but was fixed for the known cases.
If you have such a corner case, please tell the mailing list, and it should be fixed.

> 
> Furthermore, i have some queries about the wireshark integration.
> The wireshark intefration supports the GSMTAP protocol. this protocol is 
> used in order to parse the data between the SIM card and the mobile 
> terminal. Does this protocol also supports parsing data between the USIM 
> and the mobile terminal?

Only the APDU (messages exchanged using T=0 or T=1) decoding for SIM has been implemented into wireshark.
Most of the commands in USIM are similar to SIM, but there are some exceptions where the parsing will go wrong (USIM only APDU type, and some commands).

regards,
kevin