/
tlv_utils.py
278 lines (204 loc) · 9.94 KB
/
tlv_utils.py
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DO_LOG = False
import logging
import log_util
import tag_meanings
import tag_types
from tlvnode import TlvNode
from tlvtree import TlvTree
MSB_MASK = 128
BIT_6_MASK = 32
def is_constructed_tag(tag):
# tag is constructed if bit 6 is set
first_tag_byte = tag[0]
return ((first_tag_byte & BIT_6_MASK) == BIT_6_MASK)
def tag_byte_list_to_tag_str(tag_byte_list):
return ''.join(['%02X' % b for b in tag_byte_list])
def parse_tag(tlv, known_tags=None):
# determine tag, types = Extended, Simple
if not known_tags:
known_tags = []
tlv = tlv[:]
if DO_LOG: logging.info('tlv = ' + '.'.join(['%02X' % b for b in tlv]))
# considering first byte
first_tag_byte = tlv.pop(0)
# are 5 LSBs all set ?
bit_mask = 0x1F
is_extended = ((first_tag_byte & bit_mask) == bit_mask)
extended_tag_bytes = []
if is_extended:
# not all set => simple tag => tag = byte
# all set => keep popping bytes until MSB of popped byte not set
# extended tag = first byte + set of subsequent bytes, with last byte in tag having MSB not set
popped_byte = 0xFF
# keep popping until MSB is not set
while ((popped_byte & MSB_MASK) == MSB_MASK):
popped_byte = tlv.pop(0)
extended_tag_bytes.append(popped_byte)
tag = [first_tag_byte]
tag.extend(extended_tag_bytes)
if (tag_byte_list_to_tag_str(tag) not in known_tags):
return [], []
if DO_LOG: logging.info('TAG = ' + '.'.join(['%02X' % b for b in tag]))
return (tag, tlv)
def parse_length_value_remainder(byte_string):
if (len(byte_string) == 0):
return None
if DO_LOG: logging.info('parsing parse_length_value_remainder = ' + '.'.join(['%02X' % b for b in byte_string]))
# read first byte of length
first_length_byte = byte_string.pop(0)
if DO_LOG: logging.info('first_length_byte : 0x%02X = %i' % (first_length_byte, first_length_byte))
'''# length types = Complex, Simple'''
'''# complex if MSB is set'''
is_complex = ((first_length_byte & MSB_MASK) == MSB_MASK)
if DO_LOG: logging.info('is complex ? %s' % str(is_complex))
length_bytes = []
value_bytes = []
remainder_bytes = []
if not is_complex:
length_bytes.append(first_length_byte)
for i in range(first_length_byte):
try:
b = byte_string.pop(0)
value_bytes.append(b)
except IndexError:
return [], [], []
remainder_bytes.extend(byte_string)
# length is complex
else:
'''# if MSB set, then 7 LSBs define the number of subsequent bytes to read that describe length'''
length_byte_count = first_length_byte ^ MSB_MASK
if (length_byte_count == 0):
return [], [], []
if DO_LOG: logging.info('length_byte_count %i' % length_byte_count)
length_bytes.append(first_length_byte)
length_nword = []
for i in range(length_byte_count):
b = byte_string.pop(0)
length_bytes.append(b)
length_nword.append(b)
length = length_nword[0]
if DO_LOG: logging.info('length ' + '.'.join(['%02X' % x for x in length_nword]) + ' = %i' % length)
'''# !! !! !! !! !! !! !!'''
for i in range(length):
value_bytes.append(byte_string.pop(0))
remainder_bytes.extend(byte_string)
if DO_LOG: logging.info('value_bytes ' + '.'.join(['%02X' % x for x in value_bytes]))
if DO_LOG: logging.info('length = %i' % len(value_bytes))
if DO_LOG: logging.info('remainder_bytes ' + '.'.join(['%02X' % x for x in remainder_bytes]))
return (length_bytes, value_bytes, remainder_bytes)
def parse_tlv(tlv, known_tags=None, tlv_tree=None, parent_node=None):
if (len(tlv) <= 2):
return
if not known_tags:
known_tags = []
if not tlv_tree:
tlv_tree = TlvTree()
tag, length_value_remainder = parse_tag(tlv, known_tags=known_tags)
if (len(tag) == 0) or (len(length_value_remainder) == 0):
return
(length, value, remainder) = parse_length_value_remainder(length_value_remainder)
if (len(length) == 0) or (len(value) == 0):
return
tag_string = tag_byte_list_to_tag_str(tag)
if tag_string not in known_tags:
return
if not parent_node:
tlv_tree.root_node = TlvNode(tlv_tree=tlv_tree)
parent_node = tlv_tree.root_node
node = TlvNode(tlv_tree, tag_byte_list=tag, value_byte_list=value, parent_node=tlv_tree.root_node, child_nodes=[])
parent_node.add_child_node(child_node=node)
# PEERS
if len(remainder) > 0:
parse_tlv(remainder, known_tags=known_tags, tlv_tree=tlv_tree, parent_node=parent_node)
# CHILDREN
tag_is_constructed = is_constructed_tag(tag)
if (tag_is_constructed):
if DO_LOG: logging.info('tag %s is constructed ? %s' % (tag_string, str(tag_is_constructed)))
parse_tlv(value, known_tags=known_tags, tlv_tree=tlv_tree, parent_node=node)
'''
print('tag [tag length = %i]' % len(tag))
print(' '.join([hex(b) for b in tag]))
print('length_value_remainder %s' % length_value_remainder)
print(' '.join([hex(b) for b in length_value_remainder]))
'''
if (parent_node == tlv_tree.root_node):
return tlv_tree
def parse_concatted_dol_list_to_ordered_list_of_tag_and_length(clist):
'''
returns [(tag, tag_value)]
'''
ordered_components = []
rem = clist[:]
while (len(rem) > 0):
tag, remainder = parse_tag(rem, known_tags=tag_meanings.emv_tags.keys())
if (len(tag) == 0) or (len(remainder) == 0):
break
value = remainder.pop(0)
# synchronise outer var
for i in range(len(tag) + 1):
rem.pop(0)
tag_string = tag_byte_list_to_tag_str(tag)
ordered_components.append([tag_string, value])
return ordered_components
def parse_concatted_dol_list(clist):
dols_by_tag = {}
repeated_tag_counts = {}
rem = clist[:]
while (len(rem) > 0):
tag, remainder = parse_tag(rem, known_tags=tag_meanings.emv_tags.keys())
if (len(tag) == 0) or (len(remainder) == 0):
break
value = remainder.pop(0)
# synchronise outer var
for i in range(len(tag) + 1):
rem.pop(0)
tag_string = tag_byte_list_to_tag_str(tag)
# record repeats
if (tag_string in dols_by_tag):
if (tag_string in repeated_tag_counts):
repeated_tag_counts[tag_string] = repeated_tag_counts[tag_string] + 1
else:
repeated_tag_counts[tag_string] = 1
dols_by_tag[tag_string] = value
return dols_by_tag, repeated_tag_counts
def get_unqualified_tag(qualified_tag):
if ('.' not in qualified_tag):
return qualified_tag
else:
reversed = qualified_tag[::-1]
rev_tag = reversed[:reversed.find('.')]
return rev_tag[::-1]
def parse_and_report(tlv, known_tags=None):
tags = parse_tlv(tlv, known_tags=known_tags)
report = []
for tag in tags.keys():
report.append(tag.ljust(16) + tag_meanings.tags[get_unqualified_tag(tag)].ljust(60) + '.'.join(['%02X' % b for b in tags[tag]]))
return report
def report(tags, known_tags=None):
report = []
max_tag_length = 0
max_meaning_length = 0
for tag in tags.keys():
if (len(tag) > max_tag_length):
max_tag_length = len(tag)
meaning = tag_meanings.tags[get_unqualified_tag(tag)]
if (len(meaning) > max_meaning_length):
max_meaning_length = len(meaning)
for tag in sorted(tags.keys()):
left_text = tag.ljust(max_tag_length + 2) + tag_meanings.tags[get_unqualified_tag(tag)].ljust(max_meaning_length + 2) + ('(%i) ' % len(tags[tag])).ljust(10)
report.append(left_text + 'H: ' + '.'.join(['%02X' % b for b in tags[tag]]))
right_text = 'A: ' + ''.join([chr(b) if (b >= 31) else '-' for b in tags[tag]])
if (len(right_text) > 0):
report.append(' '*len(left_text) + right_text)
return report
tag_6f = [0x6f,0x19,0x84,0x0e,0x31,0x50,0x41,0x59,0x2e,0x53,0x59,0x53,0x2e,0x44,0x44,0x46,0x30,0x31,0xa5,0x07,0x88,0x01,0x01,0x9f,0x11,0x01,0x01]
tag_70_simple = [0x70,0x54,0x5F,0x25,0x03,0x11,0x12,0x01,0x5F,0x24,0x03,0x17,0x02,0x28,0x9F,0x07,0x02,0xFF,0x00,0x5A,0x08,0x52,0x22,0x50,0x24,0x60,0x90,0x28,0x81,0x5F,0x34,0x01,0x00,0x8E,0x12,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x42,0x01,0x41,0x03,0x42,0x03,0x5E,0x03,0x1F,0x03,0x9F,0x0D,0x05,0xB8,0x60,0xF4,0x80,0x00,0x9F,0x0E,0x05,0x00,0x10,0x08,0x00,0x00,0x9F,0x0F,0x05,0xB8,0x68,0xF4,0x98,0x00,0x5F,0x28,0x02,0x07,0x10,0x9F,0x4A,0x01,0x82]
tag_70_extended = [0x70,0x81,0x93,0x90,0x81,0x90,0x64,0x8A,0xBC,0x88,0xB2,0x17,0x78,0x06,0xA3,0x8E,0x14,0x78,0x6B,0xCA,0x3F,0x4A,0x66,0xBE,0x6C,0x98,0x56,0x7D,0x34,0xF4,0x6E,0x1F,0x32,0x97,0x87,0x42,0x0D,0x16,0x72,0x25,0x97,0x42,0x17,0x0D,0x2F,0x90,0x6A,0xE7,0x08,0xA1,0xF7,0xD5,0xB3,0x1E,0x55,0xC1,0xD2,0xC6,0xFA,0x33,0xF1,0x86,0xAE,0xFA,0x3F,0xEA,0xE6,0x12,0x45,0x81,0xBD,0x49,0x7E,0xBE,0x67,0xB1,0x9D,0xC2,0x10,0x8B,0xD7,0x37,0x99,0xDE,0xA2,0x61,0x5A,0x9B,0x87,0x34,0xAD,0x25,0x44,0xCF,0x2F,0xFB,0x24,0xAF,0xA9,0x10,0xAA,0x2B,0x8D,0x5A,0x7A,0x68,0x70,0xE1,0xB9,0x04,0xFC,0xBB,0x2C,0xC5,0x70,0x77,0xD0,0xBC,0xF3,0x21,0x54,0x6A,0xA4,0x62,0xCD,0xAB,0xBF,0x85,0xCC,0x97,0xA4,0xD5,0x28,0x8D,0x73,0xDE,0x30,0x86,0xD9,0xE7,0x0E,0xD7,0x1C,0xE0,0xD5,0xDE,0x2D,0x88,0xFD,0x80]
if (__name__ == '__main__'):
log_util.init_logging(file_name='../../logs/tlv')
logging.info('\ntag_70_simple')
parse_and_report(tag_70_simple)
logging.info('\ntag_70_extended')
parse_and_report(tag_70_extended)
logging.info('\ntag_6f')
parse_and_report(tag_6f)