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Diffstat (limited to '')
| -rwxr-xr-x | scripts/radtee | 563 |
1 files changed, 563 insertions, 0 deletions
diff --git a/scripts/radtee b/scripts/radtee new file mode 100755 index 0000000..78b4bcb --- /dev/null +++ b/scripts/radtee @@ -0,0 +1,563 @@ +#!/usr/bin/env python2 +from __future__ import with_statement + +# RADIUS comparison tee v1.0 +# Sniffs local RADIUS traffic, replays incoming requests to a test +# server, and compares the sniffed responses with the responses +# generated by the test server. +# +# Copyright (c) 2009, Frontier Communications +# Copyright (c) 2010, John Morrissey <jwm@horde.net> +# +# This program is free software; you can redistribute it and/or modify it +# under the terms of the GNU General Public License as published by the Free +# Software Foundation; either version 2 of the License, or (at your option) +# any later version. +# +# This program is distributed in the hope that it will be useful, but +# WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY +# or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License +# for more details. +# +# You should have received a copy of the GNU General Public License along +# with this program; if not, write to the Free Software Foundation, Inc., 59 +# Temple Place, Suite 330, Boston, MA 02111-1307, USA. + +# Requires +# ======== +# - python 2.4 or newer +# - impacket +# - pcapy +# - pyrad, ideally 1.2 or newer + +# Output +# ====== +# - .: 50 successful, matching responses processed. +# - C=x.x.x.x: Ignored packet sniffed from unknown client. +# - D: Dropped sniffed packet due to processing bottleneck. Consider +# increasing THREADS. +# - I: Invalid/unparseable packet sniffed. +# - Mreq: Response was sniffed without sniffing a corresponding request. +# - Mresp: Request was sniffed without sniffing a corresponding response. +# - T: Request to test server timed out. + +import fcntl +from getopt import gnu_getopt, GetoptError +import os +import Queue +import re +import signal +import socket +import struct +import sys +import thread +from threading import Thread +from time import sleep, time + +from impacket.ImpactDecoder import EthDecoder +import pcapy +from pyrad.client import Client +from pyrad.dictionary import Dictionary +from pyrad import packet + + +TEST_DEST = 'server.example.com' +TEST_SECRET = 'examplesecret' + +# Dictionary to use when decoding RADIUS packets. pyrad earlier than +# v1.2 can't parse $INCLUDE directives, so you must combine FreeRADIUS' +# dictionary manually, with something like this: +# +# import re +# import sys +# +# def combine(file): +# for line in open(file): +# matches = re.search(r'^\$INCLUDE\s+(.*)$', line) +# if not matches: +# sys.stdout.write(line) +# continue +# +# combine(matches.group(1)) +# +# combine('/etc/freeradius/dictionary') +DICTIONARY = '/etc/freeradius/dictionary' + +# Number of worker threads to run. +THREADS = 32 + +# Mapping of RADIUS request source addresses to shared secrets, +# so we can decode incoming RADIUS requests. +# +# For example: +# '127.0.0.1': 'test', +CLIENTS = { +} + +# Ignore any sniffed requests from these IP addresses. +IGNORE_CLIENTS = [ +] + +# Expected mismatches to ignore and consider the packet matching. +# Only the differences are compared to these items, so only the +# differing attrs need be listed in the attrs array. +# +# Examples: +# - Ignore mismatched AccessRejects whose sole difference is a +# Reply-Message attribute with the values given. +# { +# 'sniffed': { +# 'code': packet.AccessReject, +# 'attrs': [ +# 'Reply-Message=Request Denied', +# ], +# }, +# 'test': { +# 'code': packet.AccessReject, +# 'attrs': [ +# 'Reply-Message=Account is disabled.', +# ], +# } +# }, +# +# - Ignore mismatched AccessRejects with Reply-Message=Request Denied +# and arbitrary Cisco dns-servers in the sniffed packet, and +# no Reply-Message and Cisco-AVPair attrs in the response from the +# test RADIUS server. +# { +# 'sniffed': { +# 'code': packet.AccessReject, +# 'attrs': [ +# 'Reply-Message=Request Denied', +# 'regex:^Cisco-AVPair=ip:dns-servers=.*$', +# ], +# }, +# 'test': { +# 'code': packet.AccessReject, +# 'attrs': [ +# ], +# } +# }, +# +# - Only apply this stanza to sniffed requests with +# 'User-Name= user@example.com' (note the leading whitespace). +# { +# 'check': [ +# 'User-Name= user@example.com', +# ], +# 'sniffed': { +# 'code': packet.AccessReject, +# 'attrs': [ +# 'Reply-Message=Request Denied', +# ], +# }, +# 'test': { +# 'code': packet.AccessAccept, +# 'attrs': [ +# 'Service-Type=Framed-User', +# 'Framed-Protocol=PPP', +# 'Framed-IP-Address=255.255.255.255', +# 'Framed-MTU=1500', +# 'Framed-Compression=Van-Jacobson-TCP-IP', +# ], +# } +# }, +IGNORE = [ +] + + +QUEUE = Queue.Queue(maxsize=25000) +DICT = Dictionary(DICTIONARY) + +def code2str(code): + if code == packet.AccessRequest: + return "Access-Request" + elif code == packet.AccessAccept: + return "Access-Accept" + elif code == packet.AccessReject: + return "Access-Reject" + elif code == packet.AccountingRequest: + return "Accounting-Request" + elif code == packet.AccountingResponse: + return "Accounting-Response" + elif code == packet.AccessChallenge: + return "Access-Challenge" + elif code == packet.StatusServer: + return "Status-Server" + elif code == packet.StatusClient: + return "Status-Client" + elif code == packet.DisconnectRequest: + return "Disconnect-Request" + elif code == packet.DisconnectACK: + return "Disconnect-ACK" + elif code == packet.DisconnectNAK: + return "Disconnect-NAK" + elif code == packet.CoARequest: + return "CoA-Request" + elif code == packet.CoAACK: + return "CoA-ACK" + elif code == packet.CoANAK: + return "CoA-NAK" + +def handlePacket(header, data): + """Place captured packets in the queue to be picked up + by worker threads.""" + + global QUEUE + + try: + QUEUE.put_nowait(data) + except Queue.Full: + sys.stdout.write('D') + sys.stdout.flush() + +def ignore_applies(pkt, ignore): + """Determine whether an ignore stanza (based on its check + items) applies to a packet.""" + + # All check items must match for this ignore stanza to apply. + stanza_applies = True + for pair in ignore.get('check', []): + attr, value = pair.split('=') + + if attr not in pkt: + return False + if value.startswith('regex:'): + if not re.search(value.replace('regex:', '', 1), value): + return False + elif pkt[attr] != value: + return False + + return True + +def ignores_match(pkt, mismatched, ignore): + """Determine whether mismatched AV pairs remain after accounting + for ignored differences.""" + + non_regex_ignore = [ + q + for q + in ignore['attrs'] + if not q.startswith('regex:') + ] + regex_ignore = [ + q + for q + in ignore['attrs'] + if q.startswith('regex:') + ] + + unmatched_av = mismatched[:] + unmatched_rules = ignore['attrs'][:] + for av in mismatched: + if av in non_regex_ignore: + unmatched_av.remove(av) + unmatched_rules.remove(av) + continue + for regex in regex_ignore: + if re.search(regex.replace('regex:', '', 1), av): + unmatched_av.remove(av) + if regex in unmatched_rules: + unmatched_rules.remove(regex) + break + + if unmatched_av or unmatched_rules: + return False + return True + +def matches(req, sniffed_pkt, test_pkt): + """Determine whether a response from the test server matches + the response sniffed from the wire, accounting for ignored + differences.""" + + global IGNORE + + mis_attrs_sniffed = [] + for k in sniffed_pkt.keys(): + if sorted(sniffed_pkt[k]) == sorted(test_pkt.get(k, [])): + continue + mis_attrs_sniffed.append('%s=%s' % ( + k, ', '.join([str(v) for v in sorted(sniffed_pkt[k])]))) + + mis_attrs_test = [] + for k in test_pkt.keys(): + if sorted(test_pkt[k]) == sorted(sniffed_pkt.get(k, [])): + continue + mis_attrs_test.append('%s=%s' % ( + k, ', '.join([str(v) for v in sorted(test_pkt[k])]))) + + # The packets match without having to consider any ignores. + if sniffed_pkt.code == test_pkt.code and \ + not mis_attrs_sniffed and not mis_attrs_test: + return True + + for ignore in IGNORE: + if not ignore_applies(req, ignore): + continue + + if ignore['sniffed']['code'] != sniffed_pkt.code or \ + ignore['test']['code'] != test_pkt.code: + continue + + if ignores_match(sniffed_pkt, mis_attrs_sniffed, i['sniffed']): + return True + if ignores_match(test_pkt, mis_attrs_test, i['test']): + return True + + return False + +def log_mismatch(nas, req, passwd, expected, got): + """Emit notification that the test server has returned a response + that differs from the sniffed response.""" + + print 'Mismatch: %s' % nas + + print 'Request: %s' % code2str(req.code) + for key in req.keys(): + if key == 'User-Password': + print '\t%s: %s' % (key, passwd) + continue + print '\t%s: %s' % ( + key, ', '.join([str(v) for v in req[key]])) + + print 'Expected: %s' % code2str(expected.code) + for key in expected.keys(): + print '\t%s: %s' % ( + key, ', '.join([str(v) for v in expected[key]])) + + print 'Got: %s' % code2str(got.code) + for key in got.keys(): + print '\t%s: %s' % ( + key, ', '.join([str(v) for v in got[key]])) + + print + +REQUESTS = {} +REQUESTS_LOCK = thread.allocate_lock() +NUM_SUCCESSFUL = 0 +def check_for_match(key, req_resp): + """Send a copy of the original request to the test server and + determine whether the response matches the response sniffed from + the wire.""" + + global DICT, NUM_SUCCESSFUL, TEST_DEST, TEST_SECRET + global REQUESTS, REQUESTS_LOCK + + client = Client(server=TEST_DEST, + secret=TEST_SECRET, dict=DICT) + fwd_req = client.CreateAuthPacket(code=packet.AccessRequest) + fwd_req.authenticator = req_resp['req']['pkt'].authenticator + + keys = req_resp['req']['pkt'].keys() + for k in keys: + for value in req_resp['req']['pkt'][k]: + fwd_req.AddAttribute(k, value) + if 'User-Password' in keys: + fwd_req['User-Password'] = fwd_req.PwCrypt(req_resp['req']['passwd']) + if 'NAS-IP-Address' in fwd_req: + del fwd_req['NAS-IP-Address'] + fwd_req.AddAttribute('NAS-IP-Address', req_resp['req']['ip']) + + try: + test_reply = client.SendPacket(fwd_req) + except: + # Request to test server timed out. + sys.stdout.write('T') + sys.stdout.flush() + with REQUESTS_LOCK: + del REQUESTS[key] + return + + if not matches(req_resp['req']['pkt'], + req_resp['response']['pkt'], test_reply): + + print + log_mismatch(req_resp['req']['ip'], + req_resp['req']['pkt'], + req_resp['req']['passwd'], + req_resp['response']['pkt'], test_reply) + + with REQUESTS_LOCK: + # Occasionally, this key isn't present. Maybe retransmissions + # due to a short timeout on the remote RADIUS client's end + # and a subsequent race? + if key in REQUESTS: + del REQUESTS[key] + + NUM_SUCCESSFUL += 1 + if NUM_SUCCESSFUL % 50 == 0: + sys.stdout.write('.') + sys.stdout.flush() + +class RadiusComparer(Thread): + def run(self): + global DICT, IGNORE_CLIENTS, QUEUE, REQUESTS, REQUESTS_LOCK + + while True: + data = QUEUE.get() + if not data: + return + + frame = EthDecoder().decode(data) + ip = frame.child() + udp = ip.child() + rad_raw = udp.child().get_buffer_as_string() + + try: + pkt = packet.Packet(dict=DICT, packet=rad_raw) + except packet.PacketError: + sys.stdout.write('I') + sys.stdout.flush() + continue + + if ip.get_ip_src() in IGNORE_CLIENTS: + continue + + if pkt.code == packet.AccessRequest: + auth = packet.AuthPacket(data[42:]) + auth.authenticator = pkt.authenticator + auth.secret = clients.CLIENTS.get(ip.get_ip_src(), None) + if not auth.secret: + # No configuration for this client. + sys.stdout.write('C=%s' % ip.get_ip_src()) + sys.stdout.flush() + continue + passwd = None + if 'User-Password' in pkt.keys(): + passwd = auth.PwDecrypt(pkt['User-Password'][0]) + + key = '%s:%d:%d' % (ip.get_ip_src(), + udp.get_uh_sport(), pkt.id) + do_compare = None + with REQUESTS_LOCK: + if key not in REQUESTS: + REQUESTS[key] = {} + REQUESTS[key]['req'] = { + 'ip': ip.get_ip_src(), + 'port': udp.get_uh_sport(), + 'pkt': pkt, + 'passwd': passwd, + } + REQUESTS[key]['tstamp'] = time() + if 'response' in REQUESTS[key]: + do_compare = REQUESTS[key] + + if do_compare: + check_for_match(key, do_compare) + elif pkt.code in [packet.AccessAccept, packet.AccessReject]: + key = '%s:%d:%d' % (ip.get_ip_dst(), + udp.get_uh_dport(), pkt.id) + do_compare = None + with REQUESTS_LOCK: + if key not in REQUESTS: + REQUESTS[key] = {} + REQUESTS[key]['response'] = { + 'ip': ip.get_ip_src(), + 'port': udp.get_uh_sport(), + 'pkt': pkt, + } + REQUESTS[key]['tstamp'] = time() + if 'req' in REQUESTS[key]: + do_compare = REQUESTS[key] + + if do_compare: + check_for_match(key, do_compare) + else: + print >>sys.stderr, \ + 'Unsupported packet type received: %d' % pkt.code + +class RequestsPruner(Thread): + """Prune stale request state periodically.""" + + def run(self): + global REQUESTS, REQUESTS_LOCK + + while True: + sleep(30) + + now = time() + with REQUESTS_LOCK: + keys = REQUESTS.keys() + for key in keys: + if REQUESTS[key]['tstamp'] + 60 >= now: + continue + + if 'req' not in REQUESTS[key]: + sys.stdout.write('Mreq') + sys.stdout.flush() + if 'response' not in REQUESTS[key]: + sys.stdout.write('Mresp') + sys.stdout.flush() + + del REQUESTS[key] + +def usage(): + print 'Usage: %s INTERFACE' % os.path.basename(sys.argv[0]) + print '' + print ' -h, --help display this help and exit' + +if __name__ == '__main__': + global PID_FILE + + progname = os.path.basename(sys.argv[0]) + + try: + options, iface = gnu_getopt(sys.argv[1:], 'h', ['help']) + except GetoptError, e: + print '%s: %s' % (progname, str(e)) + usage() + sys.exit(1) + + for option in options: + if option[0] == '-h' or option[0] == '--help': + usage() + sys.exit(0) + + if len(iface) != 1: + usage() + sys.exit(1) + iface = iface[0] + + if os.geteuid() != 0: + print >>sys.stderr, '%s: must be run as root.' % progname + sys.exit(1) + + for i in range(0, THREADS): + RadiusComparer().start() + RequestsPruner().start() + + s = socket.socket(socket.AF_INET, socket.SOCK_DGRAM) + + # This is Linux-specific, and there's no tenable way to make + # it portable. + # + # Unfortunately, we need the interface's IP address to filter out + # only RADIUS traffic destined for this host (avoiding traffic sent + # *by* this host, such as proxied requests or our own traffic) to + # avoid replaying requests not directed to the local radiusd. + # + # Furthermore, this only obtains the interface's *first* IP address, + # so we won't notice traffic sent to additional IP addresses on + # the given interface. + # + # This is Good Enough For Me given the effort I care to invest. + # Of course, patches enhancing this are welcome. + if os.uname()[0] == 'Linux': + local_ipaddr = socket.inet_ntoa(fcntl.ioctl( + s.fileno(), + 0x8915, # SIOCGIFADDR + struct.pack('256s', iface[:15]) + )[20:24]) + else: + raise Exception('Only the Linux operating system is currently supported.') + + p = pcapy.open_live(iface, 1600, 0, 100) + p.setfilter(''' + (dst host %s and udp and dst port 1812) or + (src host %s and udp and src port 1812)''' % \ + (local_ipaddr, local_ipaddr)) + while True: + try: + p.dispatch(1, handlePacket) + except KeyboardInterrupt: + sys.exit(0) |