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fix decoding of multi-byte tags 

move parse_tlv to generic card


git-svn-id: svn+ssh://localhost/home/henryk/svn/cyberflex-shell/trunk@69 f711b948-2313-0410-aaa9-d29f33439f0b
This commit is contained in:
hploetz 2006-05-22 01:04:32 +00:00
parent b3b052df7f
commit ac08ac1ff8
3 changed files with 26 additions and 11 deletions
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23
TLV_utils.py
View File

@ -179,14 +179,26 @@ tags = {
0x87: (binary, "Identifier of an EF containing an extension of the FCI"),
0x88: (binary, "Short EF identifier"),
0x8A: (binary, "Life cycle status byte"),
0xA5: (recurse, "Proprietary information", None),
},
}
BER_CLASSES = {
0x0: "universal",
0x1: "application",
0x2: "context-specific",
0x3: "private",
}
def tlv_unpack(data):
ber_class = (ord(data[0]) & 0xC0) >> 6
constructed = (ord(data[0]) & 0x20) != 0 ## 0 = primitive, 0x20 = constructed
tag = ord(data[0])
data = data[1:]
if (tag & 0x1F) == 0x1F:
tag = (tag << 8) | ord(data[0])
data = data[1:]
while ord(data[0]) & 0x80 == 0x80:
tag = tag << 8 + ord(data[0])
data = data[1:]
@ -206,7 +218,7 @@ def tlv_unpack(data):
value = data[:length]
rest = data[length:]
return constructed, tag, length, value, rest
return ber_class, constructed, tag, length, value, rest
def decode(data, context = None, level = 0):
result = []
@ -215,12 +227,15 @@ def decode(data, context = None, level = 0):
data = data[1:]
continue
constructed, tag, length, value, data = tlv_unpack(data)
ber_class, constructed, tag, length, value, data = tlv_unpack(data)
interpretation = tags.get(context, tags.get(None, {})).get(tag, None)
if interpretation is None:
if not constructed: interpretation = (binary, "Unknown field")
else: interpretation = (recurse, "Unknown structure", context)
if not constructed: interpretation = [binary, "Unknown field"]
else: interpretation = [recurse, "Unknown structure", context]
interpretation[1] = "%s (%s class)" % (interpretation[1], BER_CLASSES[ber_class])
interpretation = tuple(interpretation)
current = ["\t"*level]
current.append("Tag 0x%02X, Len 0x%02X, '%s':" % (tag, length, interpretation[1]))

9
cards/generic_card.py
View File

@ -1,4 +1,4 @@
import crypto_utils, utils, pycsc, binascii, fnmatch, sre
import TLV_utils, crypto_utils, utils, pycsc, binascii, fnmatch, sre
from utils import C_APDU, R_APDU
DEBUG = True
@ -58,9 +58,14 @@ class Card:
"""Reset the card."""
self.card.reconnect(init=pycsc.SCARD_RESET_CARD)
def cmd_parsetlv(self):
"Decode the TLV data in the last response"
print TLV_utils.decode(self.last_result.data)
COMMANDS = {
"reset": cmd_reset,
"verify": cmd_verify
"verify": cmd_verify,
"parse_tlv": cmd_parsetlv,
}
def _real_send(self, apdu):

5
cards/iso_7816_4_card.py
View File

@ -95,10 +95,6 @@ class ISO_7816_4_Card(Card):
print utils.hexdump(result.data)
print TLV_utils.decode(result.data)
def cmd_parsetlv(self):
"Decode the TLV data in the last response"
print TLV_utils.decode(self.last_result.data)
ATRS = list(Card.ATRS)
ATRS.extend( [
(".*", None), ## For now we accept any card
@ -110,7 +106,6 @@ class ISO_7816_4_Card(Card):
"cd": cmd_cd,
"cat": cmd_cat,
"open": cmd_open,
"parse_tlv": cmd_parsetlv,
} )
STATUS_WORDS = dict(Card.STATUS_WORDS)