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pysim-local/pySim/utils.py
Harald Welte d7901ef08d pysim.utils.decomposeATR: Fix docutils warning 
pySim/utils.py:docstring of pySim.utils.decomposeATR:9: WARNING: Block quote ends without a blank line; unexpected unindent. [docutils]

Change-Id: Ifda4ba15014ba97634fd5bd5c9b19d9110f4670e
2026-02-09 12:50:47 +00:00

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# -*- coding: utf-8 -*-
""" pySim: various utilities
"""
import json
import abc
import string
import datetime
import argparse
from io import BytesIO
from typing import Optional, List, Dict, Any, Tuple, NewType, Union
from osmocom.utils import *
from osmocom.tlv import bertlv_encode_tag, bertlv_encode_len
# Copyright (C) 2009-2010 Sylvain Munaut <tnt@246tNt.com>
# Copyright (C) 2021 Harald Welte <laforge@osmocom.org>
# Copyright (C) 2009-2022 Ludovic Rousseau
#
# 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/>.
#
# IMSI encoded format:
# For IMSI 0123456789ABCDE:
#
# | byte 1 | 2 upper | 2 lower | 3 upper | 3 lower | ... | 9 upper | 9 lower |
# | length in bytes | 0 | odd/even | 2 | 1 | ... | E | D |
#
# If the IMSI is less than 15 characters, it should be padded with 'f' from the end.
#
# The length is the total number of bytes used to encoded the IMSI. This includes the odd/even
# parity bit. E.g. an IMSI of length 14 is 8 bytes long, not 7, as it uses bytes 2 to 9 to
# encode itself.
#
# Because of this, an odd length IMSI fits exactly into len(imsi) + 1 // 2 bytes, whereas an
# even length IMSI only uses half of the last byte.
SwHexstr = NewType('SwHexstr', str)
SwMatchstr = NewType('SwMatchstr', str)
ResTuple = Tuple[Hexstr, SwHexstr]
def enc_imsi(imsi: str):
"""Converts a string IMSI into the encoded value of the EF"""
l = half_round_up(
len(imsi) + 1) # Required bytes - include space for odd/even indicator
oe = len(imsi) & 1 # Odd (1) / Even (0)
ei = '%02x' % l + swap_nibbles('%01x%s' % ((oe << 3) | 1, rpad(imsi, 15)))
return ei
def dec_imsi(ef: Hexstr) -> Optional[str]:
"""Converts an EF value to the IMSI string representation"""
if len(ef) < 4:
return None
l = int(ef[0:2], 16) * 2 # Length of the IMSI string
l = l - 1 # Encoded length byte includes oe nibble
swapped = swap_nibbles(ef[2:]).rstrip('f')
if len(swapped) < 1:
return None
oe = (int(swapped[0]) >> 3) & 1 # Odd (1) / Even (0)
if not oe:
# if even, only half of last byte was used
l = l-1
if l != len(swapped) - 1:
return None
imsi = swapped[1:]
return imsi
def dec_iccid(ef: Hexstr) -> str:
return swap_nibbles(ef).strip('f')
def enc_iccid(iccid: str) -> Hexstr:
return swap_nibbles(rpad(iccid, 20))
def sanitize_iccid(iccid: Union[int, str]) -> str:
iccid = str(iccid)
if len(iccid) < 18:
raise ValueError('ICCID input value must be at least 18 digits')
if len(iccid) > 20:
raise ValueError('ICCID input value must be at most 20 digits')
if len(iccid) == 18:
# 18 digits means we must add a luhn check digit to reach 19 digits
iccid += str(calculate_luhn(iccid))
if len(iccid) == 20:
# 20 digits means we're actually exceeding E.118 by one digit, and
# the luhn check digit must already be included
verify_luhn(iccid)
if len(iccid) == 19:
# 19 digits means that it's either an in-spec 19-digits ICCID with
# its luhn check digit already present, or it's an out-of-spec 20-digit
# ICCID without that check digit...
try:
verify_luhn(iccid)
except ValueError:
# 19th digit was not luhn check digit; we must add it
iccid += str(calculate_luhn(iccid))
return iccid
def enc_plmn(mcc: Hexstr, mnc: Hexstr) -> Hexstr:
"""Converts integer MCC/MNC into 3 bytes for EF"""
# Make sure there are no excess whitespaces in the input
# parameters
mcc = mcc.strip()
mnc = mnc.strip()
# Make sure that MCC/MNC are correctly padded with leading
# zeros or 'F', depending on the length.
if len(mnc) == 0:
mnc = "FFF"
elif len(mnc) == 1:
mnc = "0" + mnc + "F"
elif len(mnc) == 2:
mnc += "F"
if len(mcc) == 0:
mcc = "FFF"
elif len(mcc) == 1:
mcc = "00" + mcc
elif len(mcc) == 2:
mcc = "0" + mcc
return (mcc[1] + mcc[0]) + (mnc[2] + mcc[2]) + (mnc[1] + mnc[0])
def dec_plmn(threehexbytes: Hexstr) -> dict:
res = {'mcc': "0", 'mnc': "0"}
dec_mcc_from_plmn_str(threehexbytes)
res['mcc'] = dec_mcc_from_plmn_str(threehexbytes)
res['mnc'] = dec_mnc_from_plmn_str(threehexbytes)
return res
# Accepts hex string representing three bytes
def dec_mcc_from_plmn(plmn: Hexstr) -> int:
ia = h2i(plmn)
digit1 = ia[0] & 0x0F # 1st byte, LSB
digit2 = (ia[0] & 0xF0) >> 4 # 1st byte, MSB
digit3 = ia[1] & 0x0F # 2nd byte, LSB
if digit3 == 0xF and digit2 == 0xF and digit1 == 0xF:
return 0xFFF # 4095
return derive_mcc(digit1, digit2, digit3)
def dec_mcc_from_plmn_str(plmn: Hexstr) -> str:
digit1 = plmn[1] # 1st byte, LSB
digit2 = plmn[0] # 1st byte, MSB
digit3 = plmn[3] # 2nd byte, LSB
res = digit1 + digit2 + digit3
return res.upper().strip("F")
def dec_mnc_from_plmn(plmn: Hexstr) -> int:
ia = h2i(plmn)
digit1 = ia[2] & 0x0F # 3rd byte, LSB
digit2 = (ia[2] & 0xF0) >> 4 # 3rd byte, MSB
digit3 = (ia[1] & 0xF0) >> 4 # 2nd byte, MSB
if digit3 == 0xF and digit2 == 0xF and digit1 == 0xF:
return 0xFFF # 4095
return derive_mnc(digit1, digit2, digit3)
def dec_mnc_from_plmn_str(plmn: Hexstr) -> str:
digit1 = plmn[5] # 3rd byte, LSB
digit2 = plmn[4] # 3rd byte, MSB
digit3 = plmn[2] # 2nd byte, MSB
res = digit1 + digit2 + digit3
return res.upper().strip("F")
def dec_act(twohexbytes: Hexstr) -> List[str]:
act_list = [
{'bit': 15, 'name': "UTRAN"},
{'bit': 11, 'name': "NG-RAN"},
{'bit': 6, 'name': "GSM COMPACT"},
{'bit': 5, 'name': "cdma2000 HRPD"},
{'bit': 4, 'name': "cdma2000 1xRTT"},
]
ia = h2i(twohexbytes)
u16t = (ia[0] << 8) | ia[1]
sel = set()
# only the simple single-bit ones
for a in act_list:
if u16t & (1 << a['bit']):
sel.add(a['name'])
# TS 31.102 Section 4.2.5 Table 4.2.5.1
eutran_bits = u16t & 0x7000
if eutran_bits in [0x4000, 0x7000]:
sel.add("E-UTRAN WB-S1")
sel.add("E-UTRAN NB-S1")
elif eutran_bits == 0x5000:
sel.add("E-UTRAN NB-S1")
elif eutran_bits == 0x6000:
sel.add("E-UTRAN WB-S1")
# TS 31.102 Section 4.2.5 Table 4.2.5.2
gsm_bits = u16t & 0x008C
if gsm_bits in [0x0080, 0x008C]:
sel.add("GSM")
sel.add("EC-GSM-IoT")
elif u16t & 0x008C == 0x0084:
sel.add("GSM")
elif u16t & 0x008C == 0x0086:
sel.add("EC-GSM-IoT")
return sorted(list(sel))
def dec_xplmn_w_act(fivehexbytes: Hexstr) -> Dict[str, Any]:
res = {'mcc': "0", 'mnc': "0", 'act': []}
plmn_chars = 6
act_chars = 4
# first three bytes (six ascii hex chars)
plmn_str = fivehexbytes[:plmn_chars]
# two bytes after first three bytes
act_str = fivehexbytes[plmn_chars:plmn_chars + act_chars]
res['mcc'] = dec_mcc_from_plmn_str(plmn_str)
res['mnc'] = dec_mnc_from_plmn_str(plmn_str)
res['act'] = dec_act(act_str)
return res
def dec_xplmn(threehexbytes: Hexstr) -> dict:
res = {'mcc': 0, 'mnc': 0, 'act': []}
plmn_chars = 6
# first three bytes (six ascii hex chars)
plmn_str = threehexbytes[:plmn_chars]
res['mcc'] = dec_mcc_from_plmn_str(plmn_str)
res['mnc'] = dec_mnc_from_plmn_str(plmn_str)
return res
def derive_milenage_opc(ki_hex: Hexstr, op_hex: Hexstr) -> Hexstr:
"""
Run the milenage algorithm to calculate OPC from Ki and OP
"""
from Cryptodome.Cipher import AES
# pylint: disable=no-name-in-module
from Cryptodome.Util.strxor import strxor
# We pass in hex string and now need to work on bytes
ki_bytes = bytes(h2b(ki_hex))
op_bytes = bytes(h2b(op_hex))
aes = AES.new(ki_bytes, AES.MODE_ECB)
opc_bytes = aes.encrypt(op_bytes)
return b2h(strxor(opc_bytes, op_bytes))
def calculate_luhn(cc) -> int:
"""
Calculate Luhn checksum used in e.g. ICCID and IMEI
"""
num = list(map(int, str(cc)))
check_digit = 10 - sum(num[-2::-2] + [sum(divmod(d * 2, 10))
for d in num[::-2]]) % 10
return 0 if check_digit == 10 else check_digit
def verify_luhn(digits: str):
"""Verify the Luhn check digit; raises ValueError if it is incorrect."""
cd = calculate_luhn(digits[:-1])
if str(cd) != digits[-1]:
raise ValueError('Luhn check digit mismatch: should be %s but is %s' % (str(cd), digits[-1]))
def mcc_from_imsi(imsi: str) -> Optional[str]:
"""
Derive the MCC (Mobile Country Code) from the first three digits of an IMSI
"""
if imsi is None:
return None
if len(imsi) > 3:
return imsi[:3]
else:
return None
def mnc_from_imsi(imsi: str, long: bool = False) -> Optional[str]:
"""
Derive the MNC (Mobile Country Code) from the 4th to 6th digit of an IMSI
"""
if imsi is None:
return None
if len(imsi) > 3:
if long:
return imsi[3:6]
else:
return imsi[3:5]
else:
return None
def derive_mcc(digit1: int, digit2: int, digit3: int) -> int:
"""
Derive decimal representation of the MCC (Mobile Country Code)
from three given digits.
"""
mcc = 0
if digit1 != 0x0f:
mcc += digit1 * 100
if digit2 != 0x0f:
mcc += digit2 * 10
if digit3 != 0x0f:
mcc += digit3
return mcc
def derive_mnc(digit1: int, digit2: int, digit3: int = 0x0f) -> int:
"""
Derive decimal representation of the MNC (Mobile Network Code)
from two or (optionally) three given digits.
"""
mnc = 0
# 3-rd digit is optional for the MNC. If present
# the algorithm is the same as for the MCC.
if digit3 != 0x0f:
return derive_mcc(digit1, digit2, digit3)
if digit1 != 0x0f:
mnc += digit1 * 10
if digit2 != 0x0f:
mnc += digit2
return mnc
def sanitize_pin_adm(pin_adm, pin_adm_hex=None) -> Hexstr:
"""
The ADM pin can be supplied either in its hexadecimal form or as
ascii string. This function checks the supplied opts parameter and
returns the pin_adm as hex encoded string, regardless in which form
it was originally supplied by the user
"""
if pin_adm is not None:
if len(pin_adm) <= 8:
pin_adm = ''.join(['%02x' % (ord(x)) for x in pin_adm])
pin_adm = rpad(pin_adm, 16)
else:
raise ValueError("PIN-ADM needs to be <=8 digits (ascii)")
if pin_adm_hex is not None:
if len(pin_adm_hex) == 16:
pin_adm = pin_adm_hex
# Ensure that it's hex-encoded
try:
try_encode = h2b(pin_adm)
except ValueError as exc:
raise ValueError("PIN-ADM needs to be hex encoded using this option") from exc
else:
raise ValueError("PIN-ADM needs to be exactly 16 digits (hex encoded)")
return pin_adm
def get_addr_type(addr):
"""
Validates the given address and returns it's type (FQDN or IPv4 or IPv6)
Return: 0x00 (FQDN), 0x01 (IPv4), 0x02 (IPv6), None (Bad address argument given)
TODO: Handle IPv6
"""
# Empty address string
if len(addr) == 0:
return None
addr_list = addr.split('.')
# Check for IPv4/IPv6
try:
import ipaddress
# Throws ValueError if addr is not correct
ipa = ipaddress.ip_address(addr)
if ipa.version == 4:
return 0x01
elif ipa.version == 6:
return 0x02
except Exception:
invalid_ipv4 = True
for i in addr_list:
# Invalid IPv4 may qualify for a valid FQDN, so make check here
# e.g. 172.24.15.300
import re
if not re.match('^[0-9_]+$', i):
invalid_ipv4 = False
break
if invalid_ipv4:
return None
fqdn_flag = True
for i in addr_list:
# Only Alphanumeric characters and hyphen - RFC 1035
import re
if not re.match("^[a-zA-Z0-9]+(?:-[a-zA-Z0-9]+)?$", i):
fqdn_flag = False
break
# FQDN
if fqdn_flag:
return 0x00
return None
def sw_match(sw: str, pattern: str) -> bool:
"""Match given SW against given pattern."""
# Create a masked version of the returned status word
sw_lower = sw.lower()
sw_masked = ""
for i in range(0, 4):
if pattern[i] == '?':
sw_masked = sw_masked + '?'
elif pattern[i] == 'x':
sw_masked = sw_masked + 'x'
else:
sw_masked = sw_masked + sw_lower[i]
# Compare the masked version against the pattern
return sw_masked == pattern
def tabulate_str_list(str_list, width: int = 79, hspace: int = 2, lspace: int = 1,
align_left: bool = True) -> str:
"""Pretty print a list of strings into a tabulated form.
Args:
width : total width in characters per line
space : horizontal space between cells
lspace : number of spaces before row
align_lef : Align text to the left side
Returns:
multi-line string containing formatted table
"""
if str_list is None:
return ""
if len(str_list) <= 0:
return ""
longest_str = max(str_list, key=len)
cellwith = len(longest_str) + hspace
cols = width // cellwith
rows = (len(str_list) - 1) // cols + 1
table = []
for i in iter(range(rows)):
str_list_row = str_list[i::rows]
if align_left:
format_str_cell = '%%-%ds'
else:
format_str_cell = '%%%ds'
format_str_row = (format_str_cell % cellwith) * len(str_list_row)
format_str_row = (" " * lspace) + format_str_row
table.append(format_str_row % tuple(str_list_row))
return '\n'.join(table)
def expand_hex(hexstring, length):
"""Expand a given hexstring to a specified length by replacing "." or ".."
with a filler that is derived from the neighboring nibbles respective
bytes. Usually this will be the nibble respective byte before "." or
"..", except when the string begins with "." or "..", then the nibble
respective byte after "." or ".." is used.". In case the string cannot
be expanded for some reason, the input string is returned unmodified.
Args:
hexstring : hexstring to expand
length : desired length of the resulting hexstring.
Returns:
expanded hexstring
"""
# expand digit aligned
if hexstring.count(".") == 1:
pos = hexstring.index(".")
if pos > 0:
filler = hexstring[pos - 1]
else:
filler = hexstring[pos + 1]
missing = length * 2 - (len(hexstring) - 1)
if missing <= 0:
return hexstring
return hexstring.replace(".", filler * missing)
# expand byte aligned
elif hexstring.count("..") == 1:
if len(hexstring) % 2:
return hexstring
pos = hexstring.index("..")
if pos % 2:
return hexstring
if pos > 1:
filler = hexstring[pos - 2:pos]
else:
filler = hexstring[pos + 2:pos+4]
missing = length * 2 - (len(hexstring) - 2)
if missing <= 0:
return hexstring
return hexstring.replace("..", filler * (missing // 2))
# no change
return hexstring
def bytes_for_nibbles(num_nibbles: int) -> int:
"""compute the number of bytes needed to store the given number of nibbles."""
n_bytes = num_nibbles // 2
if num_nibbles & 1:
n_bytes += 1
return n_bytes
def boxed_heading_str(heading, width=80):
"""Generate a string that contains a boxed heading."""
# Auto-enlarge box if heading exceeds length
if len(heading) > width - 4:
width = len(heading) + 4
res = "#" * width
fstr = "\n# %-" + str(width - 4) + "s #\n"
res += fstr % (heading)
res += "#" * width
return res
def parse_command_apdu(apdu: bytes) -> int:
"""Parse a given command APDU and return case (see also ISO/IEC 7816-3, Table 12 and Figure 26),
lc, le and the data field.
Args:
apdu : hexstring that contains the command APDU
Returns:
tuple containing case, lc and le values of the APDU (case, lc, le, data)
"""
if len(apdu) == 4:
# Case #1, No command data field, no response data field
lc = 0
le = 0
data = b''
return (1, lc, le, data)
elif len(apdu) == 5:
# Case #2, No command data field, response data field present
lc = 0
le = apdu[4]
if le == 0:
le = 256
data = b''
return (2, lc, le, data)
elif len(apdu) > 5:
lc = apdu[4];
if lc == 0:
lc = 256
data = apdu[5:lc+5]
if len(apdu) == 5 + lc:
# Case #3, Command data field present, no response data field
le = 0
return (3, lc, le, data)
elif len(apdu) == 5 + lc + 1:
# Case #4, Command data field present, no response data field
le = apdu[5 + lc]
if le == 0:
le = 256
return (4, lc, le, data)
else:
raise ValueError('invalid APDU (%s), Lc=0x%02x (%d) does not match the length (%d) of the data field'
% (b2h(apdu), lc, lc, len(apdu[5:])))
else:
raise ValueError('invalid APDU (%s), too short!' % b2h(apdu))
# ATR handling code under GPL from parseATR: https://github.com/LudovicRousseau/pyscard-contrib
def normalizeATR(atr):
"""Transform an ATR in list of integers.
valid input formats are
"3B A7 00 40 18 80 65 A2 08 01 01 52"
"3B:A7:00:40:18:80:65:A2:08:01:01:52"
Args:
atr: string
Returns:
list of bytes
>>> normalize("3B:A7:00:40:18:80:65:A2:08:01:01:52")
[59, 167, 0, 64, 24, 128, 101, 162, 8, 1, 1, 82]
"""
atr = atr.replace(":", "")
atr = atr.replace(" ", "")
res = []
while len(atr) >= 2:
byte, atr = atr[:2], atr[2:]
res.append(byte)
if len(atr) > 0:
raise ValueError("warning: odd string, remainder: %r" % atr)
atr = [int(x, 16) for x in res]
return atr
# ATR handling code under GPL from parseATR: https://github.com/LudovicRousseau/pyscard-contrib
def decomposeATR(atr_txt):
"""Decompose the ATR in elementary fields
Args:
atr_txt: ATR as a hex bytes string
Returns:
dictionary of field and values
Example::
>>> decomposeATR("3B A7 00 40 18 80 65 A2 08 01 01 52")
{ 'T0': {'value': 167},
'TB': {1: {'value': 0}},
'TC': {2: {'value': 24}},
'TD': {1: {'value': 64}},
'TS': {'value': 59},
'atr': [59, 167, 0, 64, 24, 128, 101, 162, 8, 1, 1, 82],
'hb': {'value': [128, 101, 162, 8, 1, 1, 82]},
'hbn': 7}
"""
ATR_PROTOCOL_TYPE_T0 = 0
atr_txt = normalizeATR(atr_txt)
atr = {}
# the ATR itself as a list of integers
atr["atr"] = atr_txt
# store TS and T0
atr["TS"] = {"value": atr_txt[0]}
TDi = atr_txt[1]
atr["T0"] = {"value": TDi}
hb_length = TDi & 15
pointer = 1
# protocol number
pn = 1
# store number of historical bytes
atr["hbn"] = TDi & 0xF
while pointer < len(atr_txt):
# Check TAi is present
if (TDi | 0xEF) == 0xFF:
pointer += 1
if "TA" not in atr:
atr["TA"] = {}
atr["TA"][pn] = {"value": atr_txt[pointer]}
# Check TBi is present
if (TDi | 0xDF) == 0xFF:
pointer += 1
if "TB" not in atr:
atr["TB"] = {}
atr["TB"][pn] = {"value": atr_txt[pointer]}
# Check TCi is present
if (TDi | 0xBF) == 0xFF:
pointer += 1
if "TC" not in atr:
atr["TC"] = {}
atr["TC"][pn] = {"value": atr_txt[pointer]}
# Check TDi is present
if (TDi | 0x7F) == 0xFF:
pointer += 1
if "TD" not in atr:
atr["TD"] = {}
TDi = atr_txt[pointer]
atr["TD"][pn] = {"value": TDi}
if (TDi & 0x0F) != ATR_PROTOCOL_TYPE_T0:
atr["TCK"] = True
pn += 1
else:
break
# Store historical bytes
atr["hb"] = {"value": atr_txt[pointer + 1 : pointer + 1 + hb_length]}
# Store TCK
last = pointer + 1 + hb_length
if "TCK" in atr:
try:
atr["TCK"] = {"value": atr_txt[last]}
except IndexError:
atr["TCK"] = {"value": -1}
last += 1
if len(atr_txt) > last:
atr["extra"] = atr_txt[last:]
if len(atr["hb"]["value"]) < hb_length:
missing = hb_length - len(atr["hb"]["value"])
if missing > 1:
(t1, t2) = ("s", "are")
else:
(t1, t2) = ("", "is")
atr["warning"] = "ATR is truncated: %d byte%s %s missing" % (missing, t1, t2)
return atr
class DataObject(abc.ABC):
"""A DataObject (DO) in the sense of ISO 7816-4. Contrary to 'normal' TLVs where one
simply has any number of different TLVs that may occur in any order at any point, ISO 7816
has the habit of specifying TLV data but with very specific ordering, or specific choices of
tags at specific points in a stream. This class tries to represent this."""
def __init__(self, name: str, desc: Optional[str] = None, tag: Optional[int] = None):
"""
Args:
name: A brief, all-lowercase, underscore separated string identifier
desc: A human-readable description of what this DO represents
tag : The tag associated with this DO
"""
self.name = name
self.desc = desc
self.tag = tag
self.decoded = None
self.encoded = None
def __str__(self):
return self.name
def __repr__(self) -> str:
return '%s(%s)' % (self.__class__, self.name)
def __or__(self, other) -> 'DataObjectChoice':
"""OR-ing DataObjects together renders a DataObjectChoice."""
if isinstance(other, DataObject):
# DataObject | DataObject = DataObjectChoice
return DataObjectChoice(None, members=[self, other])
else:
raise TypeError
def __add__(self, other) -> 'DataObjectCollection':
"""ADD-ing DataObjects together renders a DataObjectCollection."""
if isinstance(other, DataObject):
# DataObject + DataObject = DataObjectCollectin
return DataObjectCollection(None, members=[self, other])
else:
raise TypeError
def _compute_tag(self) -> int:
"""Compute the tag (sometimes the tag encodes part of the value)."""
return self.tag
def to_dict(self) -> dict:
"""Return a dict in form "name: decoded_value" """
return {self.name: self.decoded}
@abc.abstractmethod
def from_bytes(self, do: bytes):
"""Parse the value part of the DO into the internal state of this instance.
Args:
do : binary encoded bytes
"""
@abc.abstractmethod
def to_bytes(self) -> bytes:
"""Encode the internal state of this instance into the TLV value part.
Returns:
binary bytes encoding the internal state
"""
def from_tlv(self, do: bytes) -> bytes:
"""Parse binary TLV representation into internal state. The resulting decoded
representation is _not_ returned, but just internalized in the object instance!
Args:
do : input bytes containing TLV-encoded representation
Returns:
bytes remaining at end of 'do' after parsing one TLV/DO.
"""
if do[0] != self.tag:
raise ValueError('%s: Can only decode tag 0x%02x' %
(self, self.tag))
length = do[1]
val = do[2:2+length]
self.from_bytes(val)
# return remaining bytes
return do[2+length:]
def to_tlv(self) -> bytes:
"""Encode internal representation to binary TLV.
Returns:
bytes encoded in TLV format.
"""
val = self.to_bytes()
return bertlv_encode_tag(self._compute_tag()) + bertlv_encode_len(len(val)) + val
# 'codec' interface
def decode(self, binary: bytes) -> Tuple[dict, bytes]:
"""Decode a single DOs from the input data.
Args:
binary : binary bytes of encoded data
Returns:
tuple of (decoded_result, binary_remainder)
"""
tag = binary[0]
if tag != self.tag:
raise ValueError('%s: Unknown Tag 0x%02x in %s; expected 0x%02x' %
(self, tag, binary, self.tag))
remainder = self.from_tlv(binary)
return (self.to_dict(), remainder)
# 'codec' interface
def encode(self) -> bytes:
return self.to_tlv()
class TL0_DataObject(DataObject):
"""Data Object that has Tag, Len=0 and no Value part."""
def __init__(self, name: str, desc: str, tag: int, val=None):
super().__init__(name, desc, tag)
self.val = val
def from_bytes(self, binary: bytes):
if len(binary) != 0:
raise ValueError
self.decoded = self.val
def to_bytes(self) -> bytes:
return b''
class DataObjectCollection:
"""A DataObjectCollection consists of multiple Data Objects identified by their tags.
A given encoded DO may contain any of them in any order, and may contain multiple instances
of each DO."""
def __init__(self, name: str, desc: Optional[str] = None, members=None):
self.name = name
self.desc = desc
self.members = members or []
self.members_by_tag = {}
self.members_by_name = {}
self.members_by_tag = {m.tag: m for m in members}
self.members_by_name = {m.name: m for m in members}
def __str__(self) -> str:
member_strs = [str(x) for x in self.members]
return '%s(%s)' % (self.name, ','.join(member_strs))
def __repr__(self) -> str:
member_strs = [repr(x) for x in self.members]
return '%s(%s)' % (self.__class__, ','.join(member_strs))
def __add__(self, other) -> 'DataObjectCollection':
"""Extending DataCollections with other DataCollections or DataObjects."""
if isinstance(other, DataObjectCollection):
# adding one collection to another
members = self.members + other.members
return DataObjectCollection(self.name, self.desc, members)
elif isinstance(other, DataObject):
# adding a member to a collection
return DataObjectCollection(self.name, self.desc, self.members + [other])
else:
raise TypeError
# 'codec' interface
def decode(self, binary: bytes) -> Tuple[List, bytes]:
"""Decode any number of DOs from the collection until the end of the input data,
or uninitialized memory (0xFF) is found.
Args:
binary : binary bytes of encoded data
Returns:
tuple of (decoded_result, binary_remainder)
"""
res = []
remainder = binary
# iterate until no binary trailer is left
while len(remainder):
tag = remainder[0]
if tag == 0xff: # uninitialized memory at the end?
return (res, remainder)
if not tag in self.members_by_tag:
raise ValueError('%s: Unknown Tag 0x%02x in %s; expected %s' %
(self, tag, remainder, self.members_by_tag.keys()))
obj = self.members_by_tag[tag]
# DO from_tlv returns remainder of binary
remainder = obj.from_tlv(remainder)
# collect our results
res.append(obj.to_dict())
return (res, remainder)
# 'codec' interface
def encode(self, decoded) -> bytes:
res = bytearray()
for i in decoded:
obj = self.members_by_name(i[0])
res.append(obj.to_tlv())
return res
class DataObjectChoice(DataObjectCollection):
"""One Data Object from within a choice, identified by its tag.
This means that exactly one member of the choice must occur, and which one occurs depends
on the tag."""
def __add__(self, other):
"""We overload the add operator here to avoid inheriting it from DataObjecCollection."""
raise TypeError
def __or__(self, other) -> 'DataObjectChoice':
"""OR-ing a Choice to another choice extends the choice, as does OR-ing a DataObject."""
if isinstance(other, DataObjectChoice):
# adding one collection to another
members = self.members + other.members
return DataObjectChoice(self.name, self.desc, members)
elif isinstance(other, DataObject):
# adding a member to a collection
return DataObjectChoice(self.name, self.desc, self.members + [other])
else:
raise TypeError
# 'codec' interface
def decode(self, binary: bytes) -> Tuple[dict, bytes]:
"""Decode a single DOs from the choice based on the tag.
Args:
binary : binary bytes of encoded data
Returns:
tuple of (decoded_result, binary_remainder)
"""
tag = binary[0]
if tag == 0xff:
return (None, binary)
if not tag in self.members_by_tag:
raise ValueError('%s: Unknown Tag 0x%02x in %s; expected %s' %
(self, tag, binary, self.members_by_tag.keys()))
obj = self.members_by_tag[tag]
remainder = obj.from_tlv(binary)
return (obj.to_dict(), remainder)
# 'codec' interface
def encode(self, decoded) -> bytes:
obj = self.members_by_name[list(decoded)[0]]
obj.decoded = list(decoded.values())[0]
return obj.to_tlv()
class DataObjectSequence:
"""A sequence of DataObjects or DataObjectChoices. This allows us to express a certain
ordered sequence of DOs or choices of DOs that have to appear as per the specification.
By wrapping them into this formal DataObjectSequence, we can offer convenience methods
for encoding or decoding an entire sequence."""
def __init__(self, name: str, desc: Optional[str] = None, sequence=None):
self.sequence = sequence or []
self.name = name
self.desc = desc
def __str__(self) -> str:
member_strs = [str(x) for x in self.sequence]
return '%s(%s)' % (self.name, ','.join(member_strs))
def __repr__(self) -> str:
member_strs = [repr(x) for x in self.sequence]
return '%s(%s)' % (self.__class__, ','.join(member_strs))
def __add__(self, other) -> 'DataObjectSequence':
"""Add (append) a DataObject or DataObjectChoice to the sequence."""
if isinstance(other, 'DataObject'):
return DataObjectSequence(self.name, self.desc, self.sequence + [other])
elif isinstance(other, 'DataObjectChoice'):
return DataObjectSequence(self.name, self.desc, self.sequence + [other])
elif isinstance(other, 'DataObjectSequence'):
return DataObjectSequence(self.name, self.desc, self.sequence + other.sequence)
# 'codec' interface
def decode(self, binary: bytes) -> Tuple[list, bytes]:
"""Decode a sequence by calling the decoder of each element in the sequence.
Args:
binary : binary bytes of encoded data
Returns:
tuple of (decoded_result, binary_remainder)
"""
remainder = binary
res = []
for e in self.sequence:
(r, remainder) = e.decode(remainder)
if r:
res.append(r)
return (res, remainder)
# 'codec' interface
def decode_multi(self, do: bytes) -> Tuple[list, bytes]:
"""Decode multiple occurrences of the sequence from the binary input data.
Args:
do : binary input data to be decoded
Returns:
list of results of the decoder of this sequences
"""
remainder = do
res = []
while len(remainder):
(r, remainder2) = self.decode(remainder)
if r:
res.append(r)
if len(remainder2) < len(remainder):
remainder = remainder2
else:
remainder = remainder2
break
return (res, remainder)
# 'codec' interface
def encode(self, decoded) -> bytes:
"""Encode a sequence by calling the encoder of each element in the sequence."""
encoded = bytearray()
i = 0
for e in self.sequence:
encoded += e.encode(decoded[i])
i += 1
return encoded
def encode_multi(self, decoded) -> bytes:
"""Encode multiple occurrences of the sequence from the decoded input data.
Args:
decoded : list of json-serializable input data; one sequence per list item
Returns:
binary encoded output data
"""
encoded = bytearray()
for d in decoded:
encoded += self.encode(d)
return encoded
class CardCommand:
"""A single card command / instruction."""
def __init__(self, name, ins, cla_list=None, desc=None):
self.name = name
self.ins = ins
self.cla_list = cla_list or []
self.cla_list = [x.lower() for x in self.cla_list]
self.desc = desc
def __str__(self):
return self.name
def __repr__(self):
return '%s(INS=%02x,CLA=%s)' % (self.name, self.ins, self.cla_list)
def match_cla(self, cla):
"""Does the given CLA match the CLA list of the command?."""
if not isinstance(cla, str):
cla = '%02u' % cla
cla = cla.lower()
for cla_match in self.cla_list:
cla_masked = ""
for i in range(0, 2):
if cla_match[i] == 'x':
cla_masked += 'x'
else:
cla_masked += cla[i]
if cla_masked == cla_match:
return True
return False
class CardCommandSet:
"""A set of card instructions, typically specified within one spec."""
def __init__(self, name, cmds=[]):
self.name = name
self.cmds = {c.ins: c for c in cmds}
def __str__(self):
return self.name
def __getitem__(self, idx):
return self.cmds[idx]
def __add__(self, other):
if isinstance(other, CardCommand):
if other.ins in self.cmds:
raise ValueError('%s: INS 0x%02x already defined: %s' %
(self, other.ins, self.cmds[other.ins]))
self.cmds[other.ins] = other
elif isinstance(other, CardCommandSet):
for c in other.cmds.keys():
self.cmds[c] = other.cmds[c]
else:
raise ValueError(
'%s: Unsupported type to add operator: %s' % (self, other))
def lookup(self, ins, cla=None):
"""look-up the command within the CommandSet."""
ins = int(ins)
if not ins in self.cmds:
return None
cmd = self.cmds[ins]
if cla and not cmd.match_cla(cla):
return None
return cmd
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