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"""
card: Library adapted to request (U)SIM cards and other types of telco cards.
Copyright (C) 2010 Benoit Michau
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, write to the Free Software Foundation, Inc.,
51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
"""
#################################
# generic functions #
# being used in smartcard specs #
#################################
from collections import deque
from smartcard.util import toBytes
# from python 2.6, format('b') allows to use 0b10010110 notation:
# much convinient
def byteToBit(byte):
'''
byteToBit(0xAB) -> [1, 0, 1, 0, 1, 0, 1, 1]
converts a byte integer value into a list of bits
'''
bit = [0, 0, 0, 0, 0, 0, 0, 0]
for i in range(8):
if byte % pow(2, i+1):
bit[7-i] = 1
byte = byte - pow(2, i)
return bit
# equivalent to the pyscard function "toASCIIBytes"
# new version of python (>2.6) seems to have a built-in "bytes" type
def stringToByte(string):
'''
stringToByte('test') -> [116, 101, 115, 116]
converts a string into a list of bytes
'''
bytelist = []
for c in string:
bytelist.extend( toBytes(c.encode('hex')) )
return bytelist
# equivalent to the pyscard function "toASCIIString"
def byteToString(bytelist):
'''
byteToString([116, 101, 115, 116]) -> 'test'
converts a list of bytes into a string
'''
string = ''
for b in bytelist:
string += chr(b)
return string
def LV_parser(bytelist):
'''
LV_parser([0x02, 0xAB, 0xCD, 0x01, 0x12, 0x34]) -> [[171, 205], [18], []]
parses Length-Value records in a list of bytes
returns a list of list of bytes
length coded on 1 byte
'''
values = []
while len(bytelist) > 0:
l = bytelist[0]
values.append( bytelist[1:1+l] )
bytelist = bytelist[1+l:]
return values
def first_TLV_parser(bytelist):
'''
first_TLV_parser([0xAA, 0x02, 0xAB, 0xCD, 0xFF, 0x00]) -> (170, 2, [171, 205])
parses first TLV format record in a list of bytelist
returns a 3-Tuple: Tag, Length, Value
Value is a list of bytes
parsing of length is ETSI'style 101.220
'''
Tag = bytelist[0]
if bytelist[1] == 0xFF:
Len = bytelist[2]*256 + bytelist[3]
Val = bytelist[4:4+Len]
else:
Len = bytelist[1]
Val = bytelist[2:2+Len]
return (Tag, Len, Val)
def TLV_parser(bytelist):
'''
TLV_parser([0xAA, ..., 0xFF]) -> [(T, L, [V]), (T, L, [V]), ...]
loops on the input list of bytes with the "first_TLV_parser()" function
returns a list of 3-Tuples
'''
ret = []
while len(bytelist) > 0:
T, L, V = first_TLV_parser(bytelist)
if T == 0xFF:
# padding bytes
break
ret.append( (T, L, V) )
# need to manage length of L
if L > 0xFE:
bytelist = bytelist[ L+4 : ]
else:
bytelist = bytelist[ L+2 : ]
return ret
def first_BERTLV_parser(bytelist):
'''
first_BERTLV_parser([0xAA, 0x02, 0xAB, 0xCD, 0xFF, 0x00])
-> ([1, 'contextual', 'constructed', 10], [1, 2], [171, 205])
parses first BER-TLV format record in a list of bytes
returns a 3-Tuple: Tag, Length, Value
Tag: [Tag class, Tag DO, Tag number]
Length: [Length of length, Length value]
Value: [Value bytes list]
parsing of length is ETSI'style 101.220
'''
# Tag class and DO
byte0 = byteToBit(bytelist[0])
if byte0[0:2] == [0, 0]:
Tag_class = 'universal'
elif byte0[0:2] == [0, 1]:
Tag_class = 'applicative'
elif byte0[0:2] == [1, 0]:
Tag_class = 'contextual'
elif byte0[0:2] == [1, 1]:
Tag_class = 'private'
if byte0[2:3] == [0]:
Tag_DO = 'primitive'
elif byte0[2:3] == [1]:
Tag_DO = 'constructed'
# Tag coded with more than 1 byte
i = 0
if byte0[3:8] == [1, 1, 1, 1, 1]:
Tag_bits = byteToBit(bytelist[1])[1:8]
i += 1
while byteToBit(bytelist[i])[0] == 1:
i += 1
Tag_bits += byteToBit(bytelist[i])[1:8]
# Tag coded with 1 byte
else:
Tag_bits = byte0[3:8]
# Tag number calculation
Tag_num = 0
for j in range(len(Tag_bits)):
Tag_num += Tag_bits[len(Tag_bits)-j-1] * pow(2, j)
# Length coded with more than 1 byte
if bytelist[i+1] & 0x80 > 0:
Len_num = bytelist[i+1] - 0x80
Len_bytes = bytelist[i+2:i+1+Len_num]
Len = 0
for j in range(len(Len_bytes)):
Len += bytelist[i+1+Len_num-j] * pow(256, j)
Val = bytelist[i+1+Len_num:i+1+Len_num+Len]
# Length coded with 1 byte
else:
Len_num = 1
Len = bytelist[i+1]
Val = bytelist[i+2:i+2+Len]
return ([i+1, Tag_class, Tag_DO, Tag_num], [Len_num, Len], Val)
#return ([Tag_class, Tag_DO, Tag_num], Len, Val)
def BERTLV_parser(bytelist):
'''
BERTLV_parser([0xAA, ..., 0xFF]) -> [([T], L, [V]), ([T], L, [V]), ...]
loops on the input bytes with the "first_BERTLV_parser()" function
returns a list of 3-Tuples containing BERTLV records
'''
ret = []
while len(bytelist) > 0:
T, L, V = first_BERTLV_parser(bytelist)
#if T == 0xFF:
# break # padding bytes
ret.append( (T[1:], L[1], V) )
# need to manage lengths of Tag and Length
bytelist = bytelist[ T[0] + L[0] + L[1] : ]
return ret
def decode_BCD(data=[]):
'''
decode_BCD([0x21, 0xFE, 0xA3]) -> '121415310'
to decode serial number (IMSI, ICCID...) from list of bytes
'''
string = ''
for B in data:
string += str( B & 0x0F )
string += str( B >> 4 )
return string
#######################################################
# Generic class to keep track of sent / received APDU #
#######################################################
class apdu_stack:
'''
input / output wrapping class
for APDU communications
allows to keep track of communications
and exchanged commands
based on the python "deque" fifo-like object
'''
def __init__(self, limit=10):
'''
initializes apdu_stack with the maximum of IO to keep track of
'''
self.apdu_stack = deque([], limit)
def push(self, apdu_response):
'''
stacks the returned response into the apdu_stack
'''
self.apdu_stack.append( apdu_response )
def __repr__(self):
'''
represents the whole stack of responses pushed on
'''
s = ''
for apdu in self.apdu_stack:
s += apdu.__repr__() + '\n'
return s
def __call__(self):
'''
calling the apdu_stack returns the last response pushed on it
'''
return self.apdu_stack[-1]
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