Hi all,
Perhaps i am completely mistaken.. If so, please make it a "learning-moment" for me ;-)
Is it possible to crate your own SIM's ? As far as i can see, these are just small smartcards. And as such, thse can be filled with the tools that come along with OpenSC.
I presume the SIM's contain a number of EF's and DF's One set that thighs a SIM to a specific operator (making it possible to SIM-lock a handy) And another set of EF's that identifies a specific user.
Within the DB of the operator, the relation between the SIM-identifier and the specific user (with his 06-number and other info) is made. (I know that the sim itself is not unique, because a college had a malfuntioning SIM, and it was replaced by another one, with the same content)
Reason why i want to fill my own sims is this; For one of our projects we are using certificates on a smartcard. Currently full-sized, but we think of putting it on a sim-sized card. And use it in a dongle along with 2Gb (bootable) flash storage.
So my questions are: 1) can you burn your own sim's 2) would there be any objections to have, beside de GSM-info, also a certificate 3) could you "clone" an existing SIM?
With regard to the last one: If i buy a couple of prepaid-sims from a operator, would it be possible to extract that info, and put it along with my own certificates on a sim of my own?
Obviously, it is no use to contact the help desks of kpn, tele2, or vodafone at this moment. But _if_ their are no technical limitations i could do a test with some of our own BTS'es. And if that pilot works, we have a business case for any interested operator.
Hans
Hi,
Is it possible to crate your own SIM's ? As far as i can see, these are just small smartcards. And as such, thse can be filled with the tools that come along with OpenSC.
I presume the SIM's contain a number of EF's and DF's One set that thighs a SIM to a specific operator (making it possible to SIM-lock a handy) And another set of EF's that identifies a specific user.
Yes, they're essentially simple smartcard and as long as you have the proper file and use the proper class byte, that will work.
However, SIM are also responsible for the execution of the A3A8 authentication algorithm through a special 'RUN GSM ALGORITHM' command and your smartcard must implement it.
Within the DB of the operator, the relation between the SIM-identifier and the specific user (with his 06-number and other info) is made. (I know that the sim itself is not unique, because a college had a malfuntioning SIM, and it was replaced by another one, with the same content)
Yes. The MISDN (phone number) has no relation to the IMSI (SIM identity) except inside the operator.
- can you burn your own sim's
Yes.
See http://shop.sysmocom.de/t/sim-card-related/sim-cards for programmable simcards. See http://cgit.osmocom.org/cgit/pysim/ for an utility to program those.
And finally see http://cgit.osmocom.org/cgit/osmo-cos/ for the beginning of a fully opensource smartcard OS you could use to implement SIM.
- would there be any objections to have, beside de GSM-info, also a
certificate
I would think so.
AFAICT the specs says you have to respond to certain command, but it doesn't say you can't answer to some additional ones not in the specs.
- could you "clone" an existing SIM?
You can't read the secret key, also the algoritmh chosen by your operator for A3A8 can be variable (and not all are known). So ... you can make a copy that includes everything except those but it will obviously not work.
With regard to the last one: If i buy a couple of prepaid-sims from a operator, would it be possible to extract that info, and put it along with my own certificates on a sim of my own?
See above : No.
Cheers,
Sylvain
On Thu, May 24, 2012 at 09:13:23AM +0200, Hans Witvliet wrote:
Is it possible to crate your own SIM's ?
Yes, but they will only work on your own GSM network, unless you have a way to install your Ki or K/OPC into the AUC of an operator (which you don't, unless you work in the core network division of an operator or have some kind of special business relationship with them.
On Thu, 2012-05-24 at 10:45 +0200, Harald Welte wrote:
On Thu, May 24, 2012 at 09:13:23AM +0200, Hans Witvliet wrote:
Is it possible to crate your own SIM's ?
Yes, but they will only work on your own GSM network, unless you have a way to install your Ki or K/OPC into the AUC of an operator (which you don't, unless you work in the core network division of an operator or have some kind of special business relationship with them.
Tnx,
Learned much, specially from your page at; http://openbsc.osmocom.org/trac/wiki/MagicSIM
During a previous pilot we established that kind of special relation ship with other operators. So handy's with our sims also work outside the scope of our own bts.
The guy doing the previous pilot had little experience with smartcards, i it looks like it is worthwhile looking into it.
Thanks again.
Hans
-
Hans Witvliet -
Harald Welte -
Sylvain Munaut