Introduce APDU/TPDU trace decoder
This introduces a new pySim.apdu module hierarchy, which contains
classes that represent TPDU/APDUs as exchanged between
SIM/UICC/USIM/ISIM card and UE.
It contains instruction level decoders for SELECT, READ BINARY and
friends, and then uses the pySim.filesystem.Runtime{Lchan,State} classes
to keep track of the currently selected EF/DF/ADF for each logical
channel, and uses the file-specific decoder classes of pySim to decode
the actual file content that is being read or written.
This provides a much more meaningful decode of protocol traces than
wireshark will ever be able to give us.
Furthermore, there's the new pySim.apdu_source set of classes which
provides "input plugins" for obtaining APDU traces in a variety of
formats. So far, GSMTAP UDP live capture and pyshark based RSPRO
live and pcap file reading are imlpemented.
Change-Id: I862d93163d495a294364168f7818641e47b18c0a
Closes: OS#5126
diff --git a/pySim/apdu_source/gsmtap.py b/pySim/apdu_source/gsmtap.py
new file mode 100644
index 0000000..fe450e2
--- /dev/null
+++ b/pySim/apdu_source/gsmtap.py
@@ -0,0 +1,57 @@
+# coding=utf-8
+
+# (C) 2022 by Harald Welte <laforge@osmocom.org>
+#
+# 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 <http://www.gnu.org/licenses/>.
+
+
+from pySim.gsmtap import GsmtapMessage, GsmtapSource
+from . import ApduSource, PacketType, CardReset
+
+from pySim.apdu.ts_102_221 import ApduCommands as UiccApduCommands
+from pySim.apdu.ts_31_102 import ApduCommands as UsimApduCommands
+from pySim.apdu.global_platform import ApduCommands as GpApduCommands
+ApduCommands = UiccApduCommands + UsimApduCommands + GpApduCommands
+
+class GsmtapApduSource(ApduSource):
+ """ApduSource for handling GSMTAP-SIM messages received via UDP, such as
+ those generated by simtrace2-sniff. Note that *if* you use IP loopback
+ and localhost addresses (which is the default), you will need to start
+ this source before starting simtrace2-sniff, as otherwise the latter will
+ claim the GSMTAP UDP port.
+ """
+ def __init__(self, bind_ip:str='127.0.0.1', bind_port:int=4729):
+ """Create a UDP socket for receiving GSMTAP-SIM messages.
+ Args:
+ bind_ip: IP address to which the socket should be bound (default: 127.0.0.1)
+ bind_port: UDP port number to which the socket should be bound (default: 4729)
+ """
+ super().__init__()
+ self.gsmtap = GsmtapSource(bind_ip, bind_port)
+
+ def read_packet(self) -> PacketType:
+ gsmtap_msg, addr = self.gsmtap.read_packet()
+ if gsmtap_msg['type'] != 'sim':
+ raise ValueError('Unsupported GSMTAP type %s' % gsmtap_msg['type'])
+ sub_type = gsmtap_msg['sub_type']
+ if sub_type == 'apdu':
+ return ApduCommands.parse_cmd_bytes(gsmtap_msg['body'])
+ elif sub_type == 'atr':
+ # card has been reset
+ return CardReset()
+ elif sub_type in ['pps_req', 'pps_rsp']:
+ # simply ignore for now
+ pass
+ else:
+ raise ValueError('Unsupported GSMTAP-SIM sub-type %s' % sub_type)