ts_102_221: The BTLV IEs FILE SIZE and TOTAL FILE SIZE have a min length

The TLV IEs FILE SIZE and TOTAL FILE SIZE have a minimum length of 2
byte. Even when the length is in the single digit range two bytes must
be used. See also: ETSI TS 102 221, section 11.1.1.4.1 and 11.1.1.4.2

Change-Id: Ief113ce8fe3bcae2c9fb2ff4138df9ccf98d26ff
This commit is contained in:
Philipp Maier 2022-05-25 15:05:58 +02:00
parent 38402eb065
commit cf079e7665
2 changed files with 6 additions and 3 deletions

View File

@ -208,10 +208,11 @@ def GsmString(n):
class GreedyInteger(Construct):
"""A variable-length integer implementation, think of combining GrredyBytes with BytesInteger."""
def __init__(self, signed=False, swapped=False):
def __init__(self, signed=False, swapped=False, minlen=0):
super().__init__()
self.signed = signed
self.swapped = swapped
self.minlen = minlen
def _parse(self, stream, context, path):
data = stream_read_entire(stream, path)
@ -239,6 +240,8 @@ class GreedyInteger(Construct):
if not isinstance(obj, integertypes):
raise IntegerError(f"value {obj} is not an integer", path=path)
length = self.__bytes_required(obj)
if length < self.minlen:
length = length + (self.minlen - length)
try:
data = integer2bytes(obj, length, self.signed)
except ValueError as e:

View File

@ -80,11 +80,11 @@ ts_102_22x_cmdset = CardCommandSet('TS 102 22x', [
# ETSI TS 102 221 11.1.1.4.2
class FileSize(BER_TLV_IE, tag=0x80):
_construct = GreedyInteger()
_construct = GreedyInteger(minlen=2)
# ETSI TS 102 221 11.1.1.4.2
class TotalFileSize(BER_TLV_IE, tag=0x81):
_construct = GreedyInteger()
_construct = GreedyInteger(minlen=2)
# ETSI TS 102 221 11.1.1.4.3
class FileDescriptor(BER_TLV_IE, tag=0x82):