diff options
Diffstat (limited to 'utils.py')
| -rw-r--r-- | utils.py | 127 |
1 files changed, 126 insertions, 1 deletions
@@ -1,4 +1,4 @@ -import pycsc, string, binascii, sys +import pycsc, string, binascii, sys, re def represent_binary_fancy(len, value, mask = 0): result = [] @@ -299,6 +299,131 @@ class C_APDU(APDU): return 3 else: return 4 + + _apduregex = re.compile(r'^\s*([0-9a-f]{2}\s*){4,}$', re.I) + _fancyapduregex = re.compile(r'^\s*([0-9a-f]{2}\s*){4,}\s*((xx|yy)\s*)?(([0-9a-f]{2}|:|\)|\(|\[|\])\s*)*$', re.I) + @staticmethod + def parse_fancy_apdu(*args): + apdu_string = " ".join(args) + if not C_APDU._fancyapduregex.match(apdu_string): + raise ValueError + + apdu_string = apdu_string.lower() + have_le = False + pos = apdu_string.find("xx") + if pos == -1: + pos = apdu_string.find("yy") + have_le = True + + apdu_head = "" + apdu_tail = apdu_string + if pos != -1: + apdu_head = apdu_string[:pos] + apdu_tail = apdu_string[pos+2:] + + if apdu_head.strip() != "" and not C_APDU._apduregex.match(apdu_head): + raise ValueError + + class Node(list): + def __init__(self, parent = None, type = None): + list.__init__(self) + self.parent = parent + self.type = type + + def make_binary(self): + "Recursively transform hex strings to binary" + for index, child in enumerate(self): + if isinstance(child,str): + child = "".join( ("".join(child.split())).split(":") ) + assert len(child) % 2 == 0 + self[index] = binascii.a2b_hex(child) + else: + child.make_binary() + + def calculate_lengths(self): + "Recursively calculate lengths and insert length counts" + self.length = 0 + index = 0 + while index < len(self): ## Can't use enumerate() due to the insert() below + child = self[index] + + if isinstance(child,str): + self.length = self.length + len(child) + else: + child.calculate_lengths() + + formatted_len = binascii.a2b_hex("%02x" % child.length) ## FIXME len > 255? + self.length = self.length + len(formatted_len) + child.length + self.insert(index, formatted_len) + index = index + 1 + + index = index + 1 + + def flatten(self, offset = 0, ignore_types=["("]): + "Recursively flatten, gather list of marks" + string_result = [] + mark_result = [] + for child in self: + if isinstance(child,str): + string_result.append(child) + offset = offset + len(child) + else: + start = offset + child_string, child_mark = child.flatten(offset, ignore_types) + string_result.append(child_string) + offset = end = offset + len(child_string) + if not child.type in ignore_types: + mark_result.append( (child.type, start, end) ) + mark_result.extend(child_mark) + + return "".join(string_result), mark_result + + + tree = Node() + current = tree + allowed_parens = {"(": ")", "[":"]"} + + for pos,char in enumerate(apdu_tail): + if char in (" ", "a", "b", "c", "d", "e", "f",":") or char.isdigit(): + if len(current) > 0 and isinstance(current[-1],str): + current[-1] = current[-1] + char + else: + current.append(str(char)) + + elif char in allowed_parens.values(): + if current.parent is None: + raise ValueError + if allowed_parens[current.type] != char: + raise ValueError + + current = current.parent + + elif char in allowed_parens.keys(): + current.append( Node(current, char) ) + current = current[-1] + + else: + raise ValueError + + if current != tree: + raise ValueError + + tree.make_binary() + tree.calculate_lengths() + + apdu_head = apdu_head.strip() + if apdu_head != "": + l = tree.length + if have_le: + l = l - 1 ## FIXME Le > 255? + formatted_len = "%02x" % l ## FIXME len > 255? + apdu_head = binascii.a2b_hex("".join( (apdu_head + formatted_len).split() )) + + apdu_tail, marks = tree.flatten(offset=0) + + apdu = C_APDU(apdu_head + apdu_tail, marks = marks) + return apdu + class R_APDU(APDU): "Class for a response APDU" |