Hi,

I'm having a trouble when using pySIM to change the authentication algorithm in a USIM-SJS1 card. Basically I want disable the 3G authentication on the card, and only use 2G authentication regardless of the network type. Anyway, here's my procedure.

In the beginning, I didn't realize there's a zecke/tmp2 branch. So i modified the the cards.py by myself. I added

data, sw = self._scc.update_binary('6F00', '03')

in the this line http://cgit.osmocom.org/pysim/tree/pySim/cards.py?h=master#n461

I learned the values '6F00' and '03' from this osmocom webpage https://openbsc.osmocom.org/trac/wiki/sysmoUSIM-SJS1.

One thing to mention that is I also commented out the self._scc.verify_chv() and update KI/IMSI statements in above. Because it always fails in the self._scc.verify_chv() step (apdu response 69xx), though I provided the adm-1 key in the CLI.

After it's done, unfortunately I found that when use ./pySim-read.py to read SIM again, it fails with apdu response 6b00. Also, the attempt to updating authentication algorithm didn't work when test in the phone.

Did I already mess up this SIM card at this point?

Then, I found there's a zecke/tmp2 branch. Tried it. Still not working either in reading (apdu response 6b00); or writing (still ails in self._scc.verify_chv() with apdu response 6983)

Please give suggestion on what I should do.

Thank you.