def __init__(self, rname=None, rtype=1, rclass=1, ttl=0, rdata=None):
self.rname = rname
self.rtype = rtype
self.rclass = rclass
self.ttl = ttl
self.rdata = rdata
# TODO Add property getters/setters
if self.rtype == QTYPE.OPT:
self.edns_len = self.rclass
self.edns_do = get_bits(self.ttl, 15)
self.edns_ver = get_bits(self.ttl, 16, 8)
self.edns_rcode = get_bits(self.ttl, 24, 8)
def __init__(self,rname=None,rtype=1,rclass=1,ttl=0,rdata=None):
self.rname = rname
self.rtype = rtype
self.rclass = rclass
self.ttl = ttl
self.rdata = rdata
# TODO Add property getters/setters
if self.rtype == QTYPE.OPT:
self.edns_len = self.rclass
self.edns_do = get_bits(self.ttl,15)
self.edns_ver = get_bits(self.ttl,16,8)
self.edns_rcode = get_bits(self.ttl,24,8)
def decode_name(self, last=-1):
"""
Orig docstring: Decode label at current offset in buffer (following pointers
to cached elements where necessary)
This method has overwritten because of Kitty. Sometimes it produces fuzzed data
with iso-8859-1 encodings that the original DNS lib can not handle because that type
of DNS domain label not exists in real world scenario but here it is.
"""
label = []
done = False
while not done:
(length,) = self.unpack("!B")
if get_bits(length, 6, 2) == 3:
# Pointer
self.offset -= 1
pointer = get_bits(self.unpack("!H")[0], 0, 14)
save = self.offset
if last == save:
raise BufferError(
f"Recursive pointer in DNSLabel [offset={self.offset:d},pointer={pointer:d},"
f"length={len(self.data):d}]")
if pointer < self.offset:
self.offset = pointer
else:
# Pointer can't point forwards
raise BufferError(
f"Invalid pointer in DNSLabel [offset={self.offset:d},pointer={pointer:d},"
f"length={len(self.data):d}]")
label.extend(self.decode_name(save).label)
self.offset = save
done = True
else:
if length > 0:
l = self.get(length)
try:
l.decode()
except:
l.decode('iso-8859-1')
label.append(l)
else:
done = True
return DNSLabel(label)
def decode_name(self, last=-1):
"""
Decode label at current offset in buffer (following pointers
to cached elements where necessary)
"""
label = []
done = False
while not done:
(length, ) = self.unpack("!B")
if get_bits(length, 6, 2) == 3:
# Pointer
self.offset -= 1
pointer = get_bits(self.unpack("!H")[0], 0, 14)
save = self.offset
if last == save:
raise BufferError(
"Recursive pointer in DNSLabel [offset=%d,pointer=%d,length=%d]"
% (self.offset, pointer, len(self.data)))
if pointer < self.offset:
self.offset = pointer
else:
# Pointer can't point forwards
raise BufferError(
"Invalid pointer in DNSLabel [offset=%d,pointer=%d,length=%d]"
% (self.offset, pointer, len(self.data)))
label.extend(self.decode_name(save).label)
self.offset = save
done = True
else:
if length > 0:
l = self.get(length)
try:
l.decode()
except UnicodeDecodeError:
raise BufferError("Invalid label <%s>" % l)
label.append(l)
else:
done = True
return DNSLabel(label)
def decode_name(self,last=-1):
"""
Decode label at current offset in buffer (following pointers
to cached elements where necessary)
"""
label = []
done = False
while not done:
(length,) = self.unpack("!B")
if get_bits(length,6,2) == 3:
# Pointer
self.offset -= 1
pointer = get_bits(self.unpack("!H")[0],0,14)
save = self.offset
if last == save:
raise BufferError("Recursive pointer in DNSLabel [offset=%d,pointer=%d,length=%d]" %
(self.offset,pointer,len(self.data)))
if pointer < self.offset:
self.offset = pointer
else:
# Pointer can't point forwards
raise BufferError("Invalid pointer in DNSLabel [offset=%d,pointer=%d,length=%d]" %
(self.offset,pointer,len(self.data)))
label.extend(self.decode_name(save).label)
self.offset = save
done = True
else:
if length > 0:
l = self.get(length)
try:
l.decode()
except UnicodeDecodeError:
raise BufferError("Invalid label <%s>" % l)
label.append(l)
else:
done = True
return DNSLabel(label)
def get_qr(self):
return get_bits(self.bitmap,15)
def get_rcode(self):
return get_bits(self.bitmap, 0, 4)
def get_ra(self):
return get_bits(self.bitmap, 7)
def get_rd(self):
return get_bits(self.bitmap, 8)
def get_tc(self):
return get_bits(self.bitmap, 9)
def get_aa(self):
return get_bits(self.bitmap, 10)
def get_opcode(self):
return get_bits(self.bitmap, 11, 4)
def get_qr(self):
return get_bits(self.bitmap, 15)
def get_rcode(self):
return get_bits(self.bitmap,0,4)
def get_ra(self):
return get_bits(self.bitmap,7)
def get_rd(self):
return get_bits(self.bitmap,8)
def get_tc(self):
return get_bits(self.bitmap,9)
def get_aa(self):
return get_bits(self.bitmap,10)
def get_opcode(self):
return get_bits(self.bitmap,11,4)
