esp32_bluetooth_classic_sni.../libs/scapy/modules/p0f.py
Matheus Eduardo Garbelini 86890704fd initial commit
todo: add documentation & wireshark dissector
2021-08-31 19:51:03 +08:00

623 lines
22 KiB
Python
Executable file

# This file is part of Scapy
# See http://www.secdev.org/projects/scapy for more information
# Copyright (C) Philippe Biondi <phil@secdev.org>
# This program is published under a GPLv2 license
"""
Clone of p0f passive OS fingerprinting
"""
from __future__ import absolute_import
from __future__ import print_function
import time
import struct
import os
import socket
import random
from scapy.data import KnowledgeBase, select_path
from scapy.config import conf
from scapy.compat import raw
from scapy.layers.inet import IP, TCP, TCPOptions
from scapy.packet import NoPayload, Packet
from scapy.error import warning, Scapy_Exception, log_runtime
from scapy.volatile import RandInt, RandByte, RandNum, RandShort, RandString
from scapy.sendrecv import sniff
from scapy.modules import six
from scapy.modules.six.moves import map, range
if conf.route is None:
# unused import, only to initialize conf.route
import scapy.route # noqa: F401
_p0fpaths = ["/etc/p0f", "/usr/share/p0f", "/opt/local"]
conf.p0f_base = select_path(_p0fpaths, "p0f.fp")
conf.p0fa_base = select_path(_p0fpaths, "p0fa.fp")
conf.p0fr_base = select_path(_p0fpaths, "p0fr.fp")
conf.p0fo_base = select_path(_p0fpaths, "p0fo.fp")
###############
# p0f stuff #
###############
# File format (according to p0f.fp) :
#
# wwww:ttt:D:ss:OOO...:QQ:OS:Details
#
# wwww - window size
# ttt - initial TTL
# D - don't fragment bit (0=unset, 1=set)
# ss - overall SYN packet size
# OOO - option value and order specification
# QQ - quirks list
# OS - OS genre
# details - OS description
class p0fKnowledgeBase(KnowledgeBase):
def __init__(self, filename):
KnowledgeBase.__init__(self, filename)
# self.ttl_range=[255]
def lazy_init(self):
try:
f = open(self.filename)
except IOError:
warning("Can't open base %s", self.filename)
return
try:
self.base = []
for line in f:
if line[0] in ["#", "\n"]:
continue
line = tuple(line.split(":"))
if len(line) < 8:
continue
def a2i(x):
if x.isdigit():
return int(x)
return x
li = [a2i(e) for e in line[1:4]]
# if li[0] not in self.ttl_range:
# self.ttl_range.append(li[0])
# self.ttl_range.sort()
self.base.append((line[0], li[0], li[1], li[2], line[4],
line[5], line[6], line[7][:-1]))
except Exception:
warning("Can't parse p0f database (new p0f version ?)")
self.base = None
f.close()
p0f_kdb, p0fa_kdb, p0fr_kdb, p0fo_kdb = None, None, None, None
def p0f_load_knowledgebases():
global p0f_kdb, p0fa_kdb, p0fr_kdb, p0fo_kdb
p0f_kdb = p0fKnowledgeBase(conf.p0f_base)
p0fa_kdb = p0fKnowledgeBase(conf.p0fa_base)
p0fr_kdb = p0fKnowledgeBase(conf.p0fr_base)
p0fo_kdb = p0fKnowledgeBase(conf.p0fo_base)
p0f_load_knowledgebases()
def p0f_selectdb(flags):
# tested flags: S, R, A
if flags & 0x16 == 0x2:
# SYN
return p0f_kdb
elif flags & 0x16 == 0x12:
# SYN/ACK
return p0fa_kdb
elif flags & 0x16 in [0x4, 0x14]:
# RST RST/ACK
return p0fr_kdb
elif flags & 0x16 == 0x10:
# ACK
return p0fo_kdb
else:
return None
def packet2p0f(pkt):
pkt = pkt.copy()
pkt = pkt.__class__(raw(pkt))
while pkt.haslayer(IP) and pkt.haslayer(TCP):
pkt = pkt.getlayer(IP)
if isinstance(pkt.payload, TCP):
break
pkt = pkt.payload
if not isinstance(pkt, IP) or not isinstance(pkt.payload, TCP):
raise TypeError("Not a TCP/IP packet")
# if pkt.payload.flags & 0x7 != 0x02: #S,!F,!R
# raise TypeError("Not a SYN or SYN/ACK packet")
db = p0f_selectdb(pkt.payload.flags)
# t = p0f_kdb.ttl_range[:]
# t += [pkt.ttl]
# t.sort()
# ttl=t[t.index(pkt.ttl)+1]
ttl = pkt.ttl
ss = len(pkt)
# from p0f/config.h : PACKET_BIG = 100
if ss > 100:
if db == p0fr_kdb:
# p0fr.fp: "Packet size may be wildcarded. The meaning of
# wildcard is, however, hardcoded as 'size >
# PACKET_BIG'"
ss = '*'
else:
ss = 0
if db == p0fo_kdb:
# p0fo.fp: "Packet size MUST be wildcarded."
ss = '*'
ooo = ""
mss = -1
qqT = False
qqP = False
# qqBroken = False
ilen = (pkt.payload.dataofs << 2) - 20 # from p0f.c
for option in pkt.payload.options:
ilen -= 1
if option[0] == "MSS":
ooo += "M" + str(option[1]) + ","
mss = option[1]
# FIXME: qqBroken
ilen -= 3
elif option[0] == "WScale":
ooo += "W" + str(option[1]) + ","
# FIXME: qqBroken
ilen -= 2
elif option[0] == "Timestamp":
if option[1][0] == 0:
ooo += "T0,"
else:
ooo += "T,"
if option[1][1] != 0:
qqT = True
ilen -= 9
elif option[0] == "SAckOK":
ooo += "S,"
ilen -= 1
elif option[0] == "NOP":
ooo += "N,"
elif option[0] == "EOL":
ooo += "E,"
if ilen > 0:
qqP = True
else:
if isinstance(option[0], str):
ooo += "?%i," % TCPOptions[1][option[0]]
else:
ooo += "?%i," % option[0]
# FIXME: ilen
ooo = ooo[:-1]
if ooo == "":
ooo = "."
win = pkt.payload.window
if mss != -1:
if mss != 0 and win % mss == 0:
win = "S" + str(win / mss)
elif win % (mss + 40) == 0:
win = "T" + str(win / (mss + 40))
win = str(win)
qq = ""
if db == p0fr_kdb:
if pkt.payload.flags & 0x10 == 0x10:
# p0fr.fp: "A new quirk, 'K', is introduced to denote
# RST+ACK packets"
qq += "K"
# The two next cases should also be only for p0f*r*, but although
# it's not documented (or I have not noticed), p0f seems to
# support the '0' and 'Q' quirks on any databases (or at the least
# "classical" p0f.fp).
if pkt.payload.seq == pkt.payload.ack:
# p0fr.fp: "A new quirk, 'Q', is used to denote SEQ number
# equal to ACK number."
qq += "Q"
if pkt.payload.seq == 0:
# p0fr.fp: "A new quirk, '0', is used to denote packets
# with SEQ number set to 0."
qq += "0"
if qqP:
qq += "P"
if pkt.id == 0:
qq += "Z"
if pkt.options != []:
qq += "I"
if pkt.payload.urgptr != 0:
qq += "U"
if pkt.payload.reserved != 0:
qq += "X"
if pkt.payload.ack != 0:
qq += "A"
if qqT:
qq += "T"
if db == p0fo_kdb:
if pkt.payload.flags & 0x20 != 0:
# U
# p0fo.fp: "PUSH flag is excluded from 'F' quirk checks"
qq += "F"
else:
if pkt.payload.flags & 0x28 != 0:
# U or P
qq += "F"
if db != p0fo_kdb and not isinstance(pkt.payload.payload, NoPayload):
# p0fo.fp: "'D' quirk is not checked for."
qq += "D"
# FIXME : "!" - broken options segment: not handled yet
if qq == "":
qq = "."
return (db, (win, ttl, pkt.flags.DF, ss, ooo, qq))
def p0f_correl(x, y):
d = 0
# wwww can be "*" or "%nn". "Tnn" and "Snn" should work fine with
# the x[0] == y[0] test.
d += (x[0] == y[0] or y[0] == "*" or (y[0][0] == "%" and x[0].isdigit() and (int(x[0]) % int(y[0][1:])) == 0)) # noqa: E501
# ttl
d += (y[1] >= x[1] and y[1] - x[1] < 32)
for i in [2, 5]:
d += (x[i] == y[i] or y[i] == '*')
# '*' has a special meaning for ss
d += x[3] == y[3]
xopt = x[4].split(",")
yopt = y[4].split(",")
if len(xopt) == len(yopt):
same = True
for i in range(len(xopt)):
if not (xopt[i] == yopt[i] or
(len(yopt[i]) == 2 and len(xopt[i]) > 1 and
yopt[i][1] == "*" and xopt[i][0] == yopt[i][0]) or
(len(yopt[i]) > 2 and len(xopt[i]) > 1 and
yopt[i][1] == "%" and xopt[i][0] == yopt[i][0] and
int(xopt[i][1:]) % int(yopt[i][2:]) == 0)):
same = False
break
if same:
d += len(xopt)
return d
@conf.commands.register
def p0f(pkt):
"""Passive OS fingerprinting: which OS emitted this TCP packet ?
p0f(packet) -> accuracy, [list of guesses]
"""
db, sig = packet2p0f(pkt)
if db:
pb = db.get_base()
else:
pb = []
if not pb:
warning("p0f base empty.")
return []
# s = len(pb[0][0])
r = []
max = len(sig[4].split(",")) + 5
for b in pb:
d = p0f_correl(sig, b)
if d == max:
r.append((b[6], b[7], b[1] - pkt[IP].ttl))
return r
def prnp0f(pkt):
"""Calls p0f and returns a user-friendly output"""
# we should print which DB we use
try:
r = p0f(pkt)
except Exception:
return
if r == []:
r = ("UNKNOWN", "[" + ":".join(map(str, packet2p0f(pkt)[1])) + ":?:?]", None) # noqa: E501
else:
r = r[0]
uptime = None
try:
uptime = pkt2uptime(pkt)
except Exception:
pass
if uptime == 0:
uptime = None
res = pkt.sprintf("%IP.src%:%TCP.sport% - " + r[0] + " " + r[1])
if uptime is not None:
res += pkt.sprintf(" (up: " + str(uptime / 3600) + " hrs)\n -> %IP.dst%:%TCP.dport% (%TCP.flags%)") # noqa: E501
else:
res += pkt.sprintf("\n -> %IP.dst%:%TCP.dport% (%TCP.flags%)")
if r[2] is not None:
res += " (distance " + str(r[2]) + ")"
print(res)
@conf.commands.register
def pkt2uptime(pkt, HZ=100):
"""Calculate the date the machine which emitted the packet booted using TCP timestamp # noqa: E501
pkt2uptime(pkt, [HZ=100])"""
if not isinstance(pkt, Packet):
raise TypeError("Not a TCP packet")
if isinstance(pkt, NoPayload):
raise TypeError("Not a TCP packet")
if not isinstance(pkt, TCP):
return pkt2uptime(pkt.payload)
for opt in pkt.options:
if opt[0] == "Timestamp":
# t = pkt.time - opt[1][0] * 1.0/HZ
# return time.ctime(t)
t = opt[1][0] / HZ
return t
raise TypeError("No timestamp option")
def p0f_impersonate(pkt, osgenre=None, osdetails=None, signature=None,
extrahops=0, mtu=1500, uptime=None):
"""Modifies pkt so that p0f will think it has been sent by a
specific OS. If osdetails is None, then we randomly pick up a
personality matching osgenre. If osgenre and signature are also None,
we use a local signature (using p0f_getlocalsigs). If signature is
specified (as a tuple), we use the signature.
For now, only TCP Syn packets are supported.
Some specifications of the p0f.fp file are not (yet) implemented."""
pkt = pkt.copy()
# pkt = pkt.__class__(raw(pkt))
while pkt.haslayer(IP) and pkt.haslayer(TCP):
pkt = pkt.getlayer(IP)
if isinstance(pkt.payload, TCP):
break
pkt = pkt.payload
if not isinstance(pkt, IP) or not isinstance(pkt.payload, TCP):
raise TypeError("Not a TCP/IP packet")
db = p0f_selectdb(pkt.payload.flags)
if osgenre:
pb = db.get_base()
if pb is None:
pb = []
pb = [x for x in pb if x[6] == osgenre]
if osdetails:
pb = [x for x in pb if x[7] == osdetails]
elif signature:
pb = [signature]
else:
pb = p0f_getlocalsigs()[db]
if db == p0fr_kdb:
# 'K' quirk <=> RST+ACK
if pkt.payload.flags & 0x4 == 0x4:
pb = [x for x in pb if 'K' in x[5]]
else:
pb = [x for x in pb if 'K' not in x[5]]
if not pb:
raise Scapy_Exception("No match in the p0f database")
pers = pb[random.randint(0, len(pb) - 1)]
# options (we start with options because of MSS)
# Take the options already set as "hints" to use in the new packet if we
# can. MSS, WScale and Timestamp can all be wildcarded in a signature, so
# we'll use the already-set values if they're valid integers.
orig_opts = dict(pkt.payload.options)
int_only = lambda val: val if isinstance(val, six.integer_types) else None
mss_hint = int_only(orig_opts.get('MSS'))
wscale_hint = int_only(orig_opts.get('WScale'))
ts_hint = [int_only(o) for o in orig_opts.get('Timestamp', (None, None))]
options = []
if pers[4] != '.':
for opt in pers[4].split(','):
if opt[0] == 'M':
# MSS might have a maximum size because of window size
# specification
if pers[0][0] == 'S':
maxmss = (2**16 - 1) // int(pers[0][1:])
else:
maxmss = (2**16 - 1)
# disregard hint if out of range
if mss_hint and not 0 <= mss_hint <= maxmss:
mss_hint = None
# If we have to randomly pick up a value, we cannot use
# scapy RandXXX() functions, because the value has to be
# set in case we need it for the window size value. That's
# why we use random.randint()
if opt[1:] == '*':
if mss_hint is not None:
options.append(('MSS', mss_hint))
else:
options.append(('MSS', random.randint(1, maxmss)))
elif opt[1] == '%':
coef = int(opt[2:])
if mss_hint is not None and mss_hint % coef == 0:
options.append(('MSS', mss_hint))
else:
options.append((
'MSS', coef * random.randint(1, maxmss // coef)))
else:
options.append(('MSS', int(opt[1:])))
elif opt[0] == 'W':
if wscale_hint and not 0 <= wscale_hint < 2**8:
wscale_hint = None
if opt[1:] == '*':
if wscale_hint is not None:
options.append(('WScale', wscale_hint))
else:
options.append(('WScale', RandByte()))
elif opt[1] == '%':
coef = int(opt[2:])
if wscale_hint is not None and wscale_hint % coef == 0:
options.append(('WScale', wscale_hint))
else:
options.append((
'WScale', coef * RandNum(min=1, max=(2**8 - 1) // coef))) # noqa: E501
else:
options.append(('WScale', int(opt[1:])))
elif opt == 'T0':
options.append(('Timestamp', (0, 0)))
elif opt == 'T':
# Determine first timestamp.
if uptime is not None:
ts_a = uptime
elif ts_hint[0] and 0 < ts_hint[0] < 2**32:
# Note: if first ts is 0, p0f registers it as "T0" not "T",
# hence we don't want to use the hint if it was 0.
ts_a = ts_hint[0]
else:
ts_a = random.randint(120, 100 * 60 * 60 * 24 * 365)
# Determine second timestamp.
if 'T' not in pers[5]:
ts_b = 0
elif ts_hint[1] and 0 < ts_hint[1] < 2**32:
ts_b = ts_hint[1]
else:
# FIXME: RandInt() here does not work (bug (?) in
# TCPOptionsField.m2i often raises "OverflowError:
# long int too large to convert to int" in:
# oval = struct.pack(ofmt, *oval)"
# Actually, this is enough to often raise the error:
# struct.pack('I', RandInt())
ts_b = random.randint(1, 2**32 - 1)
options.append(('Timestamp', (ts_a, ts_b)))
elif opt == 'S':
options.append(('SAckOK', ''))
elif opt == 'N':
options.append(('NOP', None))
elif opt == 'E':
options.append(('EOL', None))
elif opt[0] == '?':
if int(opt[1:]) in TCPOptions[0]:
optname = TCPOptions[0][int(opt[1:])][0]
optstruct = TCPOptions[0][int(opt[1:])][1]
options.append((optname,
struct.unpack(optstruct,
RandString(struct.calcsize(optstruct))._fix()))) # noqa: E501
else:
options.append((int(opt[1:]), ''))
# FIXME: qqP not handled
else:
warning("unhandled TCP option " + opt)
pkt.payload.options = options
# window size
if pers[0] == '*':
pkt.payload.window = RandShort()
elif pers[0].isdigit():
pkt.payload.window = int(pers[0])
elif pers[0][0] == '%':
coef = int(pers[0][1:])
pkt.payload.window = coef * RandNum(min=1, max=(2**16 - 1) // coef)
elif pers[0][0] == 'T':
pkt.payload.window = mtu * int(pers[0][1:])
elif pers[0][0] == 'S':
# needs MSS set
mss = [x for x in options if x[0] == 'MSS']
if not mss:
raise Scapy_Exception("TCP window value requires MSS, and MSS option not set") # noqa: E501
pkt.payload.window = mss[0][1] * int(pers[0][1:])
else:
raise Scapy_Exception('Unhandled window size specification')
# ttl
pkt.ttl = pers[1] - extrahops
# DF flag
pkt.flags |= (2 * pers[2])
# FIXME: ss (packet size) not handled (how ? may be with D quirk
# if present)
# Quirks
if pers[5] != '.':
for qq in pers[5]:
# FIXME: not handled: P, I, X, !
# T handled with the Timestamp option
if qq == 'Z':
pkt.id = 0
elif qq == 'U':
pkt.payload.urgptr = RandShort()
elif qq == 'A':
pkt.payload.ack = RandInt()
elif qq == 'F':
if db == p0fo_kdb:
pkt.payload.flags |= 0x20 # U
else:
pkt.payload.flags |= random.choice([8, 32, 40]) # P/U/PU
elif qq == 'D' and db != p0fo_kdb:
pkt /= conf.raw_layer(load=RandString(random.randint(1, 10))) # XXX p0fo.fp # noqa: E501
elif qq == 'Q':
pkt.payload.seq = pkt.payload.ack
# elif qq == '0': pkt.payload.seq = 0
# if db == p0fr_kdb:
# '0' quirk is actually not only for p0fr.fp (see
# packet2p0f())
if '0' in pers[5]:
pkt.payload.seq = 0
elif pkt.payload.seq == 0:
pkt.payload.seq = RandInt()
while pkt.underlayer:
pkt = pkt.underlayer
return pkt
def p0f_getlocalsigs():
"""This function returns a dictionary of signatures indexed by p0f
db (e.g., p0f_kdb, p0fa_kdb, ...) for the local TCP/IP stack.
You need to have your firewall at least accepting the TCP packets
from/to a high port (30000 <= x <= 40000) on your loopback interface.
Please note that the generated signatures come from the loopback
interface and may (are likely to) be different than those generated on
"normal" interfaces."""
pid = os.fork()
port = random.randint(30000, 40000)
if pid > 0:
# parent: sniff
result = {}
def addresult(res):
# TODO: wildcard window size in some cases? and maybe some
# other values?
if res[0] not in result:
result[res[0]] = [res[1]]
else:
if res[1] not in result[res[0]]:
result[res[0]].append(res[1])
# XXX could we try with a "normal" interface using other hosts
iface = conf.route.route('127.0.0.1')[0]
# each packet is seen twice: S + RA, S + SA + A + FA + A
# XXX are the packets also seen twice on non Linux systems ?
count = 14
pl = sniff(iface=iface, filter='tcp and port ' + str(port), count=count, timeout=3) # noqa: E501
for pkt in pl:
for elt in packet2p0f(pkt):
addresult(elt)
os.waitpid(pid, 0)
elif pid < 0:
log_runtime.error("fork error")
else:
# child: send
# XXX erk
time.sleep(1)
s1 = socket.socket(socket.AF_INET, type=socket.SOCK_STREAM)
# S & RA
try:
s1.connect(('127.0.0.1', port))
except socket.error:
pass
# S, SA, A, FA, A
s1.bind(('127.0.0.1', port))
s1.connect(('127.0.0.1', port))
# howto: get an RST w/o ACK packet
s1.close()
os._exit(0)
return result