class SCTPChunkParamRandom(_SCTPChunkParam, Packet):
fields_desc = [ ShortEnumField("type", 0x8002, sctpchunkparamtypes),
FieldLenField("len", None, length_of="random",
adjust = lambda pkt,x:x+4),
PadField(StrLenField("random", RandBin(32),
length_from=lambda pkt: pkt.len-4),
4, padwith=b"\x00"),]
def in6_getRandomizedIfaceId(ifaceid, previous=None):
# type: (str, Optional[str]) -> Tuple[str, str]
"""
Implements the interface ID generation algorithm described in RFC 3041.
The function takes the Modified EUI-64 interface identifier generated
as described in RFC 4291 and an optional previous history value (the
first element of the output of this function). If no previous interface
identifier is provided, a random one is generated. The function returns
a tuple containing the randomized interface identifier and the history
value (for possible future use). Input and output values are provided in
a "printable" format as depicted below.
ex::
>>> in6_getRandomizedIfaceId('20b:93ff:feeb:2d3')
('4c61:76ff:f46a:a5f3', 'd006:d540:db11:b092')
>>> in6_getRandomizedIfaceId('20b:93ff:feeb:2d3',
previous='d006:d540:db11:b092')
('fe97:46fe:9871:bd38', 'eeed:d79c:2e3f:62e')
"""
s = b""
if previous is None:
b_previous = bytes(RandBin(8))
else:
b_previous = inet_pton(socket.AF_INET6, "::" + previous)[8:]
s = inet_pton(socket.AF_INET6, "::" + ifaceid)[8:] + b_previous
import hashlib
s = hashlib.md5(s).digest()
s1, s2 = s[:8], s[8:]
s1 = chb(orb(s1[0]) & (~0x04)) + s1[1:] # set bit 6 to 0
bs1 = inet_ntop(socket.AF_INET6, b"\xff" * 8 + s1)[20:]
bs2 = inet_ntop(socket.AF_INET6, b"\xff" * 8 + s2)[20:]
return (bs1, bs2)
def randval(self):
if self.null_terminated:
try:
l = self.length_from(None) - 1
except:
l = RandTermString(RandNum(0, self.max_length), "\x00")
return RandBin(l)
return StrFixedLenField.randval(self)
class CGA_Params(Packet):
name = "CGA Parameters data structure"
fields_desc = [
StrFixedLenField("modifier", RandBin(size=16), length=16),
StrFixedLenField("subprefix", "", length=8),
ByteField("cc", 0),
PacketField("pubkey", X509_SubjectPublicKeyInfo(),
X509_SubjectPublicKeyInfo)
]
def __init__(self, size=None, rndstr=None):
if size is None:
size = RandNumExpo(0.05)
self.size = size
if rndstr is None:
rndstr = RandBin(RandNum(0, 255))
self.rndstr = rndstr
self._opts = list(DHCPOptions.values())
self._opts.remove("pad")
self._opts.remove("end")
def randval(self):
try:
l = self.length_from(None)
except:
l = RandTermString(RandNum(0, self.max_length), "\x00")
return RandBin(l)
def gen_nonce(size):
"""Return a nonce of @size element of random bytes as a string"""
return raw(RandBin(size))
def randval(self):
return RandBin(RandNum(0, self.max_length() or 1200))
