# coding=utf-8 """Representation of the ISO7816-4 filesystem model. The File (and its derived classes) represent the structure / hierarchy of the ISO7816-4 smart card file system with the MF, DF, EF and ADF entries, further sub-divided into the EF sub-types Transparent, Linear Fixed, etc. The classes are intended to represent the *specification* of the filesystem, not the actual contents / runtime state of interacting with a given smart card. (C) 2021 by Harald Welte This program is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 2 of the License, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program. If not, see . """ import code import json import cmd2 from cmd2 import CommandSet, with_default_category, with_argparser import argparse from pySim.utils import sw_match, h2b, b2h, is_hex from pySim.exceptions import * class CardFile(object): """Base class for all objects in the smart card filesystem. Serve as a common ancestor to all other file types; rarely used directly. """ RESERVED_NAMES = ['..', '.', '/', 'MF'] RESERVED_FIDS = ['3f00'] def __init__(self, fid=None, sfid=None, name=None, desc=None, parent=None): if not isinstance(self, CardADF) and fid == None: raise ValueError("fid is mandatory") if fid: fid = fid.lower() self.fid = fid # file identifier self.sfid = sfid # short file identifier self.name = name # human readable name self.desc = desc # human readable description self.parent = parent if self.parent and self.parent != self and self.fid: self.parent.add_file(self) self.shell_commands = [] # Note: the basic properties (fid, name, ect.) are verified when # the file is attached to a parent file. See method add_file() in # class Card DF def __str__(self): if self.name: return self.name else: return self.fid def _path_element(self, prefer_name): if prefer_name and self.name: return self.name else: return self.fid def fully_qualified_path(self, prefer_name=True): """Return fully qualified path to file as list of FID or name strings.""" if self.parent != self: ret = self.parent.fully_qualified_path(prefer_name) else: ret = [] ret.append(self._path_element(prefer_name)) return ret def get_mf(self): """Return the MF (root) of the file system.""" if self.parent == None: return None # iterate towards the top. MF has parent == self node = self while node.parent != node: node = node.parent return node def _get_self_selectables(self, alias=None, flags = []): """Return a dict of {'identifier': self} tuples""" sels = {} if alias: sels.update({alias: self}) if self.fid and (flags == [] or 'FIDS' in flags): sels.update({self.fid: self}) if self.name and (flags == [] or 'FNAMES' in flags): sels.update({self.name: self}) return sels def get_selectables(self, flags = []): """Return a dict of {'identifier': File} that is selectable from the current file.""" sels = {} # we can always select ourself if flags == [] or 'SELF' in flags: sels = self._get_self_selectables('.', flags) # we can always select our parent if flags == [] or 'PARENT' in flags: sels = self.parent._get_self_selectables('..', flags) # if we have a MF, we can always select its applications if flags == [] or 'MF' in flags: mf = self.get_mf() if mf: sels.update(mf._get_self_selectables(flags = flags)) sels.update(mf.get_app_selectables(flags = flags)) return sels def get_selectable_names(self, flags = []): """Return a list of strings for all identifiers that are selectable from the current file.""" sels = self.get_selectables(flags) return sels.keys() def decode_select_response(self, data_hex): """Decode the response to a SELECT command.""" return self.parent.decode_select_response(data_hex) class CardDF(CardFile): """DF (Dedicated File) in the smart card filesystem. Those are basically sub-directories.""" @with_default_category('DF/ADF Commands') class ShellCommands(CommandSet): def __init__(self): super().__init__() def __init__(self, **kwargs): if not isinstance(self, CardADF): if not 'fid' in kwargs: raise TypeError('fid is mandatory for all DF') super().__init__(**kwargs) self.children = dict() self.shell_commands = [self.ShellCommands()] def __str__(self): return "DF(%s)" % (super().__str__()) def add_file(self, child, ignore_existing=False): """Add a child (DF/EF) to this DF""" if not isinstance(child, CardFile): raise TypeError("Expected a File instance") if not is_hex(child.fid, minlen = 4, maxlen = 4): raise ValueError("File name %s is not a valid fid" % (child.fid)) if child.name in CardFile.RESERVED_NAMES: raise ValueError("File name %s is a reserved name" % (child.name)) if child.fid in CardFile.RESERVED_FIDS: raise ValueError("File fid %s is a reserved fid" % (child.fid)) if child.fid in self.children: if ignore_existing: return raise ValueError("File with given fid %s already exists" % (child.fid)) if self.lookup_file_by_sfid(child.sfid): raise ValueError("File with given sfid %s already exists" % (child.sfid)) if self.lookup_file_by_name(child.name): if ignore_existing: return raise ValueError("File with given name %s already exists" % (child.name)) self.children[child.fid] = child child.parent = self def add_files(self, children, ignore_existing=False): """Add a list of child (DF/EF) to this DF""" for child in children: self.add_file(child, ignore_existing) def get_selectables(self, flags = []): """Get selectable (DF/EF names) from current DF""" # global selectables + our children sels = super().get_selectables(flags) if flags == [] or 'FIDS' in flags: sels.update({x.fid: x for x in self.children.values() if x.fid}) if flags == [] or 'FNAMES' in flags: sels.update({x.name: x for x in self.children.values() if x.name}) return sels def lookup_file_by_name(self, name): if name == None: return None for i in self.children.values(): if i.name and i.name == name: return i return None def lookup_file_by_sfid(self, sfid): if sfid == None: return None for i in self.children.values(): if i.sfid == int(sfid): return i return None def lookup_file_by_fid(self, fid): if fid in self.children: return self.children[fid] return None class CardMF(CardDF): """MF (Master File) in the smart card filesystem""" def __init__(self, **kwargs): # can be overridden; use setdefault kwargs.setdefault('fid', '3f00') kwargs.setdefault('name', 'MF') kwargs.setdefault('desc', 'Master File (directory root)') # cannot be overridden; use assignment kwargs['parent'] = self super().__init__(**kwargs) self.applications = dict() def __str__(self): return "MF(%s)" % (self.fid) def add_application(self, app): """Add an ADF (Application Dedicated File) to the MF""" if not isinstance(app, CardADF): raise TypeError("Expected an ADF instance") if app.aid in self.applications: raise ValueError("AID %s already exists" % (app.aid)) self.applications[app.aid] = app app.parent=self def get_app_names(self): """Get list of completions (AID names)""" return [x.name for x in self.applications] def get_selectables(self, flags = []): """Get list of completions (DF/EF/ADF names) from current DF""" sels = super().get_selectables(flags) sels.update(self.get_app_selectables(flags)) return sels def get_app_selectables(self, flags = []): """Get applications by AID + name""" sels = {} if flags == [] or 'AIDS' in flags: sels.update({x.aid: x for x in self.applications.values()}) if flags == [] or 'ANAMES' in flags: sels.update({x.name: x for x in self.applications.values() if x.name}) return sels def decode_select_response(self, data_hex): """Decode the response to a SELECT command.""" return data_hex class CardADF(CardDF): """ADF (Application Dedicated File) in the smart card filesystem""" def __init__(self, aid, **kwargs): super().__init__(**kwargs) self.aid = aid # Application Identifier if self.parent: self.parent.add_application(self) def __str__(self): return "ADF(%s)" % (self.aid) def _path_element(self, prefer_name): if self.name and prefer_name: return self.name else: return self.aid class CardEF(CardFile): """EF (Entry File) in the smart card filesystem""" def __init__(self, *, fid, **kwargs): kwargs['fid'] = fid super().__init__(**kwargs) def __str__(self): return "EF(%s)" % (super().__str__()) def get_selectables(self, flags = []): """Get list of completions (EF names) from current DF""" #global selectable names + those of the parent DF sels = super().get_selectables(flags) sels.update({x.name:x for x in self.parent.children.values() if x != self}) return sels class TransparentEF(CardEF): """Transparent EF (Entry File) in the smart card filesystem""" @with_default_category('Transparent EF Commands') class ShellCommands(CommandSet): def __init__(self): super().__init__() read_bin_parser = argparse.ArgumentParser() read_bin_parser.add_argument('--offset', type=int, default=0, help='Byte offset for start of read') read_bin_parser.add_argument('--length', type=int, help='Number of bytes to read') @cmd2.with_argparser(read_bin_parser) def do_read_binary(self, opts): """Read binary data from a transparent EF""" (data, sw) = self._cmd.rs.read_binary(opts.length, opts.offset) self._cmd.poutput(data) def do_read_binary_decoded(self, opts): """Read + decode data from a transparent EF""" (data, sw) = self._cmd.rs.read_binary_dec() self._cmd.poutput(json.dumps(data, indent=4)) upd_bin_parser = argparse.ArgumentParser() upd_bin_parser.add_argument('--offset', type=int, default=0, help='Byte offset for start of read') upd_bin_parser.add_argument('data', help='Data bytes (hex format) to write') @cmd2.with_argparser(upd_bin_parser) def do_update_binary(self, opts): """Update (Write) data of a transparent EF""" (data, sw) = self._cmd.rs.update_binary(opts.data, opts.offset) if data: self._cmd.poutput(data) upd_bin_dec_parser = argparse.ArgumentParser() upd_bin_dec_parser.add_argument('data', help='Abstract data (JSON format) to write') @cmd2.with_argparser(upd_bin_dec_parser) def do_update_binary_decoded(self, opts): """Encode + Update (Write) data of a transparent EF""" data_json = json.loads(opts.data) (data, sw) = self._cmd.rs.update_binary_dec(data_json) if data: self._cmd.poutput(json.dumps(data, indent=4)) def __init__(self, fid, sfid=None, name=None, desc=None, parent=None, size={1,None}): super().__init__(fid=fid, sfid=sfid, name=name, desc=desc, parent=parent) self.size = size self.shell_commands = [self.ShellCommands()] def decode_bin(self, raw_bin_data): """Decode raw (binary) data into abstract representation. Overloaded by specific classes.""" method = getattr(self, '_decode_bin', None) if callable(method): return method(raw_bin_data) method = getattr(self, '_decode_hex', None) if callable(method): return method(b2h(raw_bin_data)) return {'raw': raw_bin_data.hex()} def decode_hex(self, raw_hex_data): """Decode raw (hex string) data into abstract representation. Overloaded by specific classes.""" method = getattr(self, '_decode_hex', None) if callable(method): return method(raw_hex_data) raw_bin_data = h2b(raw_hex_data) method = getattr(self, '_decode_bin', None) if callable(method): return method(raw_bin_data) return {'raw': raw_bin_data.hex()} def encode_bin(self, abstract_data): """Encode abstract representation into raw (binary) data. Overloaded by specific classes.""" method = getattr(self, '_encode_bin', None) if callable(method): return method(abstract_data) method = getattr(self, '_encode_hex', None) if callable(method): return h2b(method(abstract_data)) raise NotImplementedError def encode_hex(self, abstract_data): """Encode abstract representation into raw (hex string) data. Overloaded by specific classes.""" method = getattr(self, '_encode_hex', None) if callable(method): return method(abstract_data) method = getattr(self, '_encode_bin', None) if callable(method): raw_bin_data = method(abstract_data) return b2h(raw_bin_data) raise NotImplementedError class LinFixedEF(CardEF): """Linear Fixed EF (Entry File) in the smart card filesystem""" @with_default_category('Linear Fixed EF Commands') class ShellCommands(CommandSet): def __init__(self): super().__init__() read_rec_parser = argparse.ArgumentParser() read_rec_parser.add_argument('record_nr', type=int, help='Number of record to be read') read_rec_parser.add_argument('--count', type=int, default=1, help='Number of records to be read, beginning at record_nr') @cmd2.with_argparser(read_rec_parser) def do_read_record(self, opts): """Read one or multiple records from a record-oriented EF""" for r in range(opts.count): recnr = opts.record_nr + r (data, sw) = self._cmd.rs.read_record(recnr) if (len(data) > 0): recstr = str(data) else: recstr = "(empty)" self._cmd.poutput("%03d %s" % (recnr, recstr)) read_rec_dec_parser = argparse.ArgumentParser() read_rec_dec_parser.add_argument('record_nr', type=int, help='Number of record to be read') @cmd2.with_argparser(read_rec_dec_parser) def do_read_record_decoded(self, opts): """Read + decode a record from a record-oriented EF""" (data, sw) = self._cmd.rs.read_record_dec(opts.record_nr) self._cmd.poutput(json.dumps(data, indent=4)) upd_rec_parser = argparse.ArgumentParser() upd_rec_parser.add_argument('record_nr', type=int, help='Number of record to be read') upd_rec_parser.add_argument('data', help='Data bytes (hex format) to write') @cmd2.with_argparser(upd_rec_parser) def do_update_record(self, opts): """Update (write) data to a record-oriented EF""" (data, sw) = self._cmd.rs.update_record(opts.record_nr, opts.data) if data: self._cmd.poutput(data) upd_rec_dec_parser = argparse.ArgumentParser() upd_rec_dec_parser.add_argument('record_nr', type=int, help='Number of record to be read') upd_rec_dec_parser.add_argument('data', help='Data bytes (hex format) to write') @cmd2.with_argparser(upd_rec_dec_parser) def do_update_record_decoded(self, opts): """Encode + Update (write) data to a record-oriented EF""" (data, sw) = self._cmd.rs.update_record_dec(opts.record_nr, opts.data) if data: self._cmd.poutput(data) def __init__(self, fid, sfid=None, name=None, desc=None, parent=None, rec_len={1,None}): super().__init__(fid=fid, sfid=sfid, name=name, desc=desc, parent=parent) self.rec_len = rec_len self.shell_commands = [self.ShellCommands()] def decode_record_hex(self, raw_hex_data): """Decode raw (hex string) data into abstract representation. Overloaded by specific classes.""" method = getattr(self, '_decode_record_hex', None) if callable(method): return method(raw_hex_data) raw_bin_data = h2b(raw_hex_data) method = getattr(self, '_decode_record_bin', None) if callable(method): return method(raw_bin_data) return {'raw': raw_bin_data.hex()} def decode_record_bin(self, raw_bin_data): """Decode raw (binary) data into abstract representation. Overloaded by specific classes.""" method = getattr(self, '_decode_record_bin', None) if callable(method): return method(raw_bin_data) raw_hex_data = b2h(raw_bin_data) method = getattr(self, '_decode_record_hex', None) if callable(method): return method(raw_hex_data) return {'raw': raw_hex_data} def encode_record_hex(self, abstract_data): """Encode abstract representation into raw (hex string) data. Overloaded by specific classes.""" method = getattr(self, '_encode_record_hex', None) if callable(method): return method(abstract_data) method = getattr(self, '_encode_record_bin', None) if callable(method): raw_bin_data = method(abstract_data) return b2h(raww_bin_data) raise NotImplementedError def encode_record_bin(self, abstract_data): """Encode abstract representation into raw (binary) data. Overloaded by specific classes.""" method = getattr(self, '_encode_record_bin', None) if callable(method): return method(abstract_data) method = getattr(self, '_encode_record_hex', None) if callable(method): return b2h(method(abstract_data)) raise NotImplementedError class CyclicEF(LinFixedEF): """Cyclic EF (Entry File) in the smart card filesystem""" # we don't really have any special support for those; just recycling LinFixedEF here def __init__(self, fid, sfid=None, name=None, desc=None, parent=None, rec_len={1,None}): super().__init__(fid=fid, sfid=sfid, name=name, desc=desc, parent=parent, rec_len=rec_len) class TransRecEF(TransparentEF): """Transparent EF (Entry File) containing fixed-size records. These are the real odd-balls and mostly look like mistakes in the specification: Specified as 'transparent' EF, but actually containing several fixed-length records inside. We add a special class for those, so the user only has to provide encoder/decoder functions for a record, while this class takes care of split / merge of records. """ def __init__(self, fid, sfid=None, name=None, desc=None, parent=None, rec_len=None, size={1,None}): super().__init__(fid=fid, sfid=sfid, name=name, desc=desc, parent=parent, size=size) self.rec_len = rec_len def decode_record_hex(self, raw_hex_data): """Decode raw (hex string) data into abstract representation. Overloaded by specific classes.""" method = getattr(self, '_decode_record_hex', None) if callable(method): return method(raw_hex_data) method = getattr(self, '_decode_record_bin', None) if callable(method): raw_bin_data = h2b(raw_hex_data) return method(raw_bin_data) return {'raw': raw_hex_data} def decode_record_bin(self, raw_bin_data): """Decode raw (hex string) data into abstract representation. Overloaded by specific classes.""" method = getattr(self, '_decode_record_bin', None) if callable(method): return method(raw_bin_data) raw_hex_data = b2h(raw_bin_data) method = getattr(self, '_decode_record_hex', None) if callable(method): return method(raw_hex_data) return {'raw': raw_hex_data} def encode_record_hex(self, abstract_data): """Encode abstract representation into raw (hex string) data. Overloaded by specific classes.""" method = getattr(self, '_encode_record_hex', None) if callable(method): return method(abstract_data) method = getattr(self, '_encode_record_bin', None) if callable(method): return h2b(method(abstract_data)) raise NotImplementedError def encode_record_bin(self, abstract_data): """Encode abstract representation into raw (binary) data. Overloaded by specific classes.""" method = getattr(self, '_encode_record_bin', None) if callable(method): return method(abstract_data) method = getattr(self, '_encode_record_hex', None) if callable(method): return h2b(method(abstract_data)) raise NotImplementedError def _decode_bin(self, raw_bin_data): chunks = [raw_bin_data[i:i+self.rec_len] for i in range(0, len(raw_bin_data), self.rec_len)] return [self.decode_record_bin(x) for x in chunks] def _encode_bin(self, abstract_data): chunks = [self.encode_record_bin(x) for x in abstract_data] # FIXME: pad to file size return b''.join(chunks) class RuntimeState(object): """Represent the runtime state of a session with a card.""" def __init__(self, card, profile): self.mf = CardMF() self.card = card self.selected_file = self.mf self.profile = profile # add applications + MF-files from profile apps = self._match_applications() for a in apps: self.mf.add_application(a) for f in self.profile.files_in_mf: self.mf.add_file(f) def _match_applications(self): """match the applications from the profile with applications on the card""" apps_profile = self.profile.applications aids_card = self.card.read_aids() apps_taken = [] if aids_card: aids_taken = [] print("AIDs on card:") for a in aids_card: for f in apps_profile: if f.aid in a: print(" %s: %s" % (f.name, a)) aids_taken.append(a) apps_taken.append(f) aids_unknown = set(aids_card) - set(aids_taken) for a in aids_unknown: print(" unknown: %s" % a) else: print("error: could not determine card applications") return apps_taken def get_cwd(self): """Obtain the current working directory.""" if isinstance(self.selected_file, CardDF): return self.selected_file else: return self.selected_file.parent def get_application(self): """Obtain the currently selected application (if any).""" # iterate upwards from selected file; check if any is an ADF node = self.selected_file while node.parent != node: if isinstance(node, CardADF): return node node = node.parent return None def interpret_sw(self, sw): """Interpret the given SW relative to the currently selected Application or the underlying profile.""" app = self.get_application() if app: # The application either comes with its own interpret_sw # method or we will use the interpret_sw method from the # card profile. if hasattr(app, "interpret_sw"): return app.interpret_sw(sw) else: return self.profile.interpret_sw(sw) return app.interpret_sw(sw) else: return self.profile.interpret_sw(sw) def probe_file(self, fid, cmd_app=None): """ blindly try to select a file and automatically add a matching file object if the file actually exists """ if not is_hex(fid, 4, 4): raise ValueError("Cannot select unknown file by name %s, only hexadecimal 4 digit FID is allowed" % fid) try: (data, sw) = self.card._scc.select_file(fid) except SwMatchError as swm: k = self.interpret_sw(swm.sw_actual) if not k: raise(swm) raise RuntimeError("%s: %s - %s" % (swm.sw_actual, k[0], k[1])) select_resp = self.selected_file.decode_select_response(data) if (select_resp['file_descriptor']['file_type'] == 'df'): f = CardDF(fid=fid, sfid=None, name="DF." + str(fid).upper(), desc="dedicated file, manually added at runtime") else: if (select_resp['file_descriptor']['structure'] == 'transparent'): f = TransparentEF(fid=fid, sfid=None, name="EF." + str(fid).upper(), desc="elementry file, manually added at runtime") else: f = LinFixedEF(fid=fid, sfid=None, name="EF." + str(fid).upper(), desc="elementry file, manually added at runtime") self.selected_file.add_files([f]) self.selected_file = f return select_resp def select(self, name, cmd_app=None): """Change current directory""" sels = self.selected_file.get_selectables() if is_hex(name): name = name.lower() # unregister commands of old file if cmd_app and self.selected_file.shell_commands: for c in self.selected_file.shell_commands: cmd_app.unregister_command_set(c) if name in sels: f = sels[name] try: if isinstance(f, CardADF): (data, sw) = self.card.select_adf_by_aid(f.aid) else: (data, sw) = self.card._scc.select_file(f.fid) self.selected_file = f except SwMatchError as swm: k = self.interpret_sw(swm.sw_actual) if not k: raise(swm) raise RuntimeError("%s: %s - %s" % (swm.sw_actual, k[0], k[1])) select_resp = f.decode_select_response(data) else: select_resp = self.probe_file(name, cmd_app) # register commands of new file if cmd_app and self.selected_file.shell_commands: for c in self.selected_file.shell_commands: cmd_app.register_command_set(c) return select_resp def read_binary(self, length=None, offset=0): if not isinstance(self.selected_file, TransparentEF): raise TypeError("Only works with TransparentEF") return self.card._scc.read_binary(self.selected_file.fid, length, offset) def read_binary_dec(self): (data, sw) = self.read_binary() dec_data = self.selected_file.decode_hex(data) print("%s: %s -> %s" % (sw, data, dec_data)) return (dec_data, sw) def update_binary(self, data_hex, offset=0): if not isinstance(self.selected_file, TransparentEF): raise TypeError("Only works with TransparentEF") return self.card._scc.update_binary(self.selected_file.fid, data_hex, offset) def update_binary_dec(self, data): data_hex = self.selected_file.encode_hex(data) print("%s -> %s" % (data, data_hex)) return self.update_binary(data_hex) def read_record(self, rec_nr=0): if not isinstance(self.selected_file, LinFixedEF): raise TypeError("Only works with Linear Fixed EF") # returns a string of hex nibbles return self.card._scc.read_record(self.selected_file.fid, rec_nr) def read_record_dec(self, rec_nr=0): (data, sw) = self.read_record(rec_nr) return (self.selected_file.decode_record_hex(data), sw) def update_record(self, rec_nr, data_hex): if not isinstance(self.selected_file, LinFixedEF): raise TypeError("Only works with Linear Fixed EF") return self.card._scc.update_record(self.selected_file.fid, rec_nr, data_hex) def update_record_dec(self, rec_nr, data): hex_data = self.selected_file.encode_record_hex(data) return self.update_record(self, rec_nr, data_hex) class FileData(object): """Represent the runtime, on-card data.""" def __init__(self, fdesc): self.desc = fdesc self.fcp = None def interpret_sw(sw_data, sw): """Interpret a given status word within the profile. Returns tuple of two strings""" for class_str, swdict in sw_data.items(): # first try direct match if sw in swdict: return (class_str, swdict[sw]) # next try wildcard matches for pattern, descr in swdict.items(): if sw_match(sw, pattern): return (class_str, descr) return None class CardApplication(object): """A card application is represented by an ADF (with contained hierarchy) and optionally some SW definitions.""" def __init__(self, name, adf=None, sw=None): self.name = name self.adf = adf self.sw = sw or dict() def __str__(self): return "APP(%s)" % (self.name) def interpret_sw(self, sw): """Interpret a given status word within the application. Returns tuple of two strings""" return interpret_sw(self.sw, sw) class CardProfile(object): """A Card Profile describes a card, it's filessystem hierarchy, an [initial] list of applications as well as profile-specific SW and shell commands. Every card has one card profile, but there may be multiple applications within that profile.""" def __init__(self, name, **kw): self.name = name self.desc = kw.get("desc", None) self.files_in_mf = kw.get("files_in_mf", []) self.sw = kw.get("sw", []) self.applications = kw.get("applications", []) self.shell_cmdsets = kw.get("shell_cmdsets", []) def __str__(self): return self.name def add_application(self, app): self.applications.append(app) def interpret_sw(self, sw): """Interpret a given status word within the profile. Returns tuple of two strings""" return interpret_sw(self.sw, sw)