From 5482737f31bdad8ab9688c35d6cda2cc17de6d96 Mon Sep 17 00:00:00 2001 From: Philipp Maier Date: Tue, 24 Oct 2023 16:18:30 +0200 Subject: [PATCH] pySim-shell: don't get trapped in applications without file system When we traverse the file system, we may also end up selecting applications (ADF), which do not support an USIM/ISIM like file system. This will leave us without the ability to select the MF (or any other file) again. The only way out is to select the ISIM or USIM application again to get the access to the file system again. Change-Id: Ia2fdd65f430c07acb1afdaf265d24c6928b654e0 Related: OS#5418 --- pySim-shell.py | 29 +++++++++++++++++++++++++++-- 1 file changed, 27 insertions(+), 2 deletions(-) diff --git a/pySim-shell.py b/pySim-shell.py index 3d8bd865..6ff484b6 100755 --- a/pySim-shell.py +++ b/pySim-shell.py @@ -54,7 +54,7 @@ from pySim.utils import sanitize_pin_adm, tabulate_str_list, boxed_heading_str, from pySim.utils import is_hexstr_or_decimal, is_hexstr, is_decimal from pySim.card_handler import CardHandler, CardHandlerAuto -from pySim.filesystem import CardDF, CardADF +from pySim.filesystem import CardMF, CardDF, CardADF from pySim.ts_102_222 import Ts102222Commands from pySim.gsm_r import DF_EIRENE from pySim.cat import ProactiveCommand @@ -518,7 +518,32 @@ class PySimCommands(CommandSet): # below, so we must not move up. if skip_df == False: self.walk(indent + 1, action_ef, action_df, context, **kwargs) - fcp_dec = self._cmd.lchan.select("..", self._cmd) + + parent = self._cmd.lchan.selected_file.parent + df = self._cmd.lchan.selected_file + adf = self._cmd.lchan.selected_adf + if isinstance(parent, CardMF) and (adf and adf.has_fs == False): + # Not every application that may be present on a GlobalPlatform card will support the SELECT + # command as we know it from ETSI TS 102 221, section 11.1.1. In fact the only subset of + # SELECT we may rely on is the OPEN SELECT command as specified in GlobalPlatform Card + # Specification, section 11.9. Unfortunately the OPEN SELECT command only supports the + # "select by name" method, which means we can only select an application and not a file. + # The consequence of this is that we may get trapped in an application that does not have + # ISIM/USIM like file system support and the only way to leave that application is to select + # an ISIM/USIM application in order to get the file system access back. + # + # To automate this escape-route while traversing the file system we will check whether + # the parent file is the MF. When this is the case and the selected ADF has no file system + # support, we will select an arbitrary ADF that has file system support first and from there + # we will then select the MF. + for selectable in parent.get_selectables().items(): + if isinstance(selectable[1], CardADF) and selectable[1].has_fs == True: + self._cmd.lchan.select(selectable[1].name, self._cmd) + break + self._cmd.lchan.select(df.get_mf().name, self._cmd) + else: + # Normal DF/ADF selection + fcp_dec = self._cmd.lchan.select("..", self._cmd) elif action_ef: df_before_action = self._cmd.lchan.selected_file