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Diffstat (limited to 'scripts/external_libs/dpkt-1.8.6.2/dpkt/asn1.py')
| -rw-r--r-- | scripts/external_libs/dpkt-1.8.6.2/dpkt/asn1.py | 121 |
1 files changed, 121 insertions, 0 deletions
diff --git a/scripts/external_libs/dpkt-1.8.6.2/dpkt/asn1.py b/scripts/external_libs/dpkt-1.8.6.2/dpkt/asn1.py new file mode 100644 index 00000000..7acae041 --- /dev/null +++ b/scripts/external_libs/dpkt-1.8.6.2/dpkt/asn1.py @@ -0,0 +1,121 @@ +# $Id: asn1.py 23 2006-11-08 15:45:33Z dugsong $ +# -*- coding: utf-8 -*- +"""Abstract Syntax Notation #1.""" + +import struct +import time +import dpkt + +# Type class +CLASSMASK = 0xc0 +UNIVERSAL = 0x00 +APPLICATION = 0x40 +CONTEXT = 0x80 +PRIVATE = 0xc0 + +# Constructed (vs. primitive) +CONSTRUCTED = 0x20 + +# Universal-class tags +TAGMASK = 0x1f +INTEGER = 2 +BIT_STRING = 3 # arbitrary bit string +OCTET_STRING = 4 # arbitrary octet string +NULL = 5 +OID = 6 # object identifier +SEQUENCE = 16 # ordered collection of types +SET = 17 # unordered collection of types +PRINT_STRING = 19 # printable string +T61_STRING = 20 # T.61 (8-bit) character string +IA5_STRING = 22 # ASCII +UTC_TIME = 23 + + +def utctime(buf): + """Convert ASN.1 UTCTime string to UTC float.""" + yy = int(buf[:2]) + mn = int(buf[2:4]) + dd = int(buf[4:6]) + hh = int(buf[6:8]) + mm = int(buf[8:10]) + try: + ss = int(buf[10:12]) + buf = buf[12:] + except TypeError: + ss = 0 + buf = buf[10:] + if buf[0] == '+': + hh -= int(buf[1:3]) + mm -= int(buf[3:5]) + elif buf[0] == '-': + hh += int(buf[1:3]) + mm += int(buf[3:5]) + return time.mktime((2000 + yy, mn, dd, hh, mm, ss, 0, 0, 0)) + + +def decode(buf): + """Sleazy ASN.1 decoder. + Return list of (id, value) tuples from ASN.1 BER/DER encoded buffer. + """ + msg = [] + while buf: + t = ord(buf[0]) + constructed = t & CONSTRUCTED + tag = t & TAGMASK + l = ord(buf[1]) + c = 0 + if constructed and l == 128: + # XXX - constructed, indefinite length + msg.append((t, decode(buf[2:]))) + elif l >= 128: + c = l & 127 + if c == 1: + l = ord(buf[2]) + elif c == 2: + l = struct.unpack('>H', buf[2:4])[0] + elif c == 3: + l = struct.unpack('>I', buf[1:5])[0] & 0xfff + c = 2 + elif c == 4: + l = struct.unpack('>I', buf[2:6])[0] + else: + # XXX - can be up to 127 bytes, but... + raise dpkt.UnpackError('excessive long-form ASN.1 length %d' % l) + + # Skip type, length + buf = buf[2 + c:] + + # Parse content + if constructed: + msg.append((t, decode(buf))) + elif tag == INTEGER: + if l == 0: + n = 0 + elif l == 1: + n = ord(buf[0]) + elif l == 2: + n = struct.unpack('>H', buf[:2])[0] + elif l == 3: + n = struct.unpack('>I', buf[:4])[0] >> 8 + elif l == 4: + n = struct.unpack('>I', buf[:4])[0] + else: + raise dpkt.UnpackError('excessive integer length > %d bytes' % l) + msg.append((t, n)) + elif tag == UTC_TIME: + msg.append((t, utctime(buf[:l]))) + else: + msg.append((t, buf[:l])) + + # Skip content + buf = buf[l:] + return msg + + +def test_asn1(): + s = '0\x82\x02Q\x02\x01\x0bc\x82\x02J\x04xcn=Douglas J Song 1, ou=Information Technology Division, ou=Faculty and Staff, ou=People, o=University of Michigan, c=US\n\x01\x00\n\x01\x03\x02\x01\x00\x02\x01\x00\x01\x01\x00\x87\x0bobjectclass0\x82\x01\xb0\x04\rmemberOfGroup\x04\x03acl\x04\x02cn\x04\x05title\x04\rpostalAddress\x04\x0ftelephoneNumber\x04\x04mail\x04\x06member\x04\thomePhone\x04\x11homePostalAddress\x04\x0bobjectClass\x04\x0bdescription\x04\x18facsimileTelephoneNumber\x04\x05pager\x04\x03uid\x04\x0cuserPassword\x04\x08joinable\x04\x10associatedDomain\x04\x05owner\x04\x0erfc822ErrorsTo\x04\x08ErrorsTo\x04\x10rfc822RequestsTo\x04\nRequestsTo\x04\tmoderator\x04\nlabeledURL\x04\nonVacation\x04\x0fvacationMessage\x04\x05drink\x04\x0elastModifiedBy\x04\x10lastModifiedTime\x04\rmodifiersname\x04\x0fmodifytimestamp\x04\x0ccreatorsname\x04\x0fcreatetimestamp' + assert (decode(s) == [(48, [(2, 11), (99, [(4, 'cn=Douglas J Song 1, ou=Information Technology Division, ou=Faculty and Staff, ou=People, o=University of Michigan, c=US'), (10, '\x00'), (10, '\x03'), (2, 0), (2, 0), (1, '\x00'), (135, 'objectclass'), (48, [(4, 'memberOfGroup'), (4, 'acl'), (4, 'cn'), (4, 'title'), (4, 'postalAddress'), (4, 'telephoneNumber'), (4, 'mail'), (4, 'member'), (4, 'homePhone'), (4, 'homePostalAddress'), (4, 'objectClass'), (4, 'description'), (4, 'facsimileTelephoneNumber'), (4, 'pager'), (4, 'uid'), (4, 'userPassword'), (4, 'joinable'), (4, 'associatedDomain'), (4, 'owner'), (4, 'rfc822ErrorsTo'), (4, 'ErrorsTo'), (4, 'rfc822RequestsTo'), (4, 'RequestsTo'), (4, 'moderator'), (4, 'labeledURL'), (4, 'onVacation'), (4, 'vacationMessage'), (4, 'drink'), (4, 'lastModifiedBy'), (4, 'lastModifiedTime'), (4, 'modifiersname'), (4, 'modifytimestamp'), (4, 'creatorsname'), (4, 'createtimestamp')])])])]) + +if __name__ == '__main__': + test_asn1() + print 'Tests Successful...'
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