# Author: Hubert Kario, (c) 2016 # Released under Gnu GPL v2.0, see LICENSE file for details """Check handling of malformed ECDHE_RSA client key exchange messages""" from __future__ import print_function import traceback import sys import getopt from random import sample import re from itertools import chain from tlsfuzzer.runner import Runner from tlsfuzzer.messages import Connect, ClientHelloGenerator, \ ClientKeyExchangeGenerator, ChangeCipherSpecGenerator, \ FinishedGenerator, ApplicationDataGenerator, AlertGenerator, \ fuzz_message, truncate_handshake, pad_handshake, \ TCPBufferingEnable, TCPBufferingDisable, TCPBufferingFlush from tlsfuzzer.expect import ExpectServerHello, ExpectCertificate, \ ExpectServerHelloDone, ExpectChangeCipherSpec, ExpectFinished, \ ExpectAlert, ExpectClose, ExpectServerKeyExchange, \ ExpectApplicationData from tlslite.constants import CipherSuite, AlertLevel, AlertDescription, \ ExtensionType, GroupName, ECPointFormat from tlslite.extensions import SupportedGroupsExtension, \ ECPointFormatsExtension from tlsfuzzer.utils.lists import natural_sort_keys version = 3 def help_msg(): print("Usage: [-h hostname] [-p port] [[probe-name] ...]") print(" -h hostname name of the host to run the test against") print(" localhost by default") print(" -p port port number to use for connection, 4433 by default") print(" probe-name if present, will run only the probes with given") print(" names and not all of them, e.g \"sanity\"") print(" -e probe-name exclude the probe from the list of the ones run") print(" may be specified multiple times") print(" -n num run 'num' or all(if 0) tests instead of default(all)") print(" (excluding \"sanity\" tests)") print(" -x probe-name expect the probe to fail. When such probe passes despite being marked like this") print(" it will be reported in the test summary and the whole script will fail.") print(" May be specified multiple times.") print(" -X message expect the `message` substring in exception raised during") print(" execution of preceding expected failure probe") print(" usage: [-x probe-name] [-X exception], order is compulsory!") print(" --help this message") def main(): """Check handling of malformed ECDHE_RSA client key exchange messages""" host = "localhost" port = 4433 num_limit = None run_exclude = set() expected_failures = {} last_exp_tmp = None argv = sys.argv[1:] opts, args = getopt.getopt(argv, "h:p:e:n:x:X:", ["help"]) for opt, arg in opts: if opt == '-h': host = arg elif opt == '-p': port = int(arg) elif opt == '-e': run_exclude.add(arg) elif opt == '-n': num_limit = int(arg) elif opt == '-x': expected_failures[arg] = None last_exp_tmp = str(arg) elif opt == '-X': if not last_exp_tmp: raise ValueError("-x has to be specified before -X") expected_failures[last_exp_tmp] = str(arg) elif opt == '--help': help_msg() sys.exit(0) else: raise ValueError("Unknown option: {0}".format(opt)) if args: run_only = set(args) else: run_only = None conversations = {} conversation = Connect(host, port) node = conversation ciphers = [CipherSuite.TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA] ext = {ExtensionType.renegotiation_info: None, ExtensionType.supported_groups: SupportedGroupsExtension(). create([GroupName.secp256r1]), ExtensionType.ec_point_formats: ECPointFormatsExtension(). create([ECPointFormat.uncompressed])} node = node.add_child(ClientHelloGenerator(ciphers, extensions=ext)) ext = {ExtensionType.renegotiation_info: None, ExtensionType.ec_point_formats: None} node = node.add_child(ExpectServerHello(extensions=ext)) node = node.add_child(ExpectCertificate()) node = node.add_child(ExpectServerKeyExchange()) node = node.add_child(ExpectServerHelloDone()) node = node.add_child(ClientKeyExchangeGenerator()) node = node.add_child(ChangeCipherSpecGenerator()) node = node.add_child(FinishedGenerator()) node = node.add_child(ExpectChangeCipherSpec()) node = node.add_child(ExpectFinished()) node = node.add_child(ApplicationDataGenerator( bytearray(b"GET / HTTP/1.0\n\n"))) node = node.add_child(ExpectApplicationData()) node = node.add_child(AlertGenerator(AlertLevel.warning, AlertDescription.close_notify)) node = node.add_child(ExpectAlert()) node.next_sibling = ExpectClose() conversations["sanity"] = conversation # invalid ecdh_Yc value conversation = Connect(host, port) node = conversation ciphers = [CipherSuite.TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA] ext = {ExtensionType.renegotiation_info: None, ExtensionType.supported_groups: SupportedGroupsExtension(). create([GroupName.secp256r1]), ExtensionType.ec_point_formats: ECPointFormatsExtension(). create([ECPointFormat.uncompressed])} node = node.add_child(ClientHelloGenerator(ciphers, extensions=ext)) ext = {ExtensionType.renegotiation_info: None, ExtensionType.ec_point_formats: None} node = node.add_child(ExpectServerHello(extensions=ext)) node = node.add_child(ExpectCertificate()) node = node.add_child(ExpectServerKeyExchange()) node = node.add_child(ExpectServerHelloDone()) node = node.add_child(TCPBufferingEnable()) subst = dict((i, 0x00) for i in range(-1, -65, -1)) subst[-1] = 0x01 node = node.add_child(fuzz_message(ClientKeyExchangeGenerator(), substitutions=subst)) node = node.add_child(ChangeCipherSpecGenerator()) node = node.add_child(FinishedGenerator()) node = node.add_child(TCPBufferingDisable()) node = node.add_child(TCPBufferingFlush()) node = node.add_child(ExpectAlert(AlertLevel.fatal, AlertDescription.illegal_parameter)) node = node.add_child(ExpectClose()) conversations["invalid point (0, 1)"] = conversation # invalid ecdh_Yc value conversation = Connect(host, port) node = conversation ciphers = [CipherSuite.TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA] ext = {ExtensionType.renegotiation_info: None, ExtensionType.supported_groups: SupportedGroupsExtension(). create([GroupName.secp256r1]), ExtensionType.ec_point_formats: ECPointFormatsExtension(). create([ECPointFormat.uncompressed])} node = node.add_child(ClientHelloGenerator(ciphers, extensions=ext)) ext = {ExtensionType.renegotiation_info: None, ExtensionType.ec_point_formats: None} node = node.add_child(ExpectServerHello(extensions=ext)) node = node.add_child(ExpectCertificate()) node = node.add_child(ExpectServerKeyExchange()) node = node.add_child(ExpectServerHelloDone()) node = node.add_child(TCPBufferingEnable()) # point at infinity doesn't have a defined encoding, but some libraries # encode it as 0, 0, check if it is rejected subst = dict((i, 0x00) for i in range(-1, -65, -1)) node = node.add_child(fuzz_message(ClientKeyExchangeGenerator(), substitutions=subst)) node = node.add_child(ChangeCipherSpecGenerator()) node = node.add_child(FinishedGenerator()) node = node.add_child(TCPBufferingDisable()) node = node.add_child(TCPBufferingFlush()) node = node.add_child(ExpectAlert(AlertLevel.fatal, AlertDescription.illegal_parameter)) node = node.add_child(ExpectClose()) conversations["invalid point (0, 0)"] = conversation # invalid ecdh_Yc value conversation = Connect(host, port) node = conversation ciphers = [CipherSuite.TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA] ext = {ExtensionType.renegotiation_info: None, ExtensionType.supported_groups: SupportedGroupsExtension(). create([GroupName.secp256r1]), ExtensionType.ec_point_formats: ECPointFormatsExtension(). create([ECPointFormat.uncompressed])} node = node.add_child(ClientHelloGenerator(ciphers, extensions=ext)) ext = {ExtensionType.renegotiation_info: None, ExtensionType.ec_point_formats: None} node = node.add_child(ExpectServerHello(extensions=ext)) node = node.add_child(ExpectCertificate()) node = node.add_child(ExpectServerKeyExchange()) node = node.add_child(ExpectServerHelloDone()) node = node.add_child(TCPBufferingEnable()) # uncompressed EC points need to be self consistent, by changing # one coordinate without changing the other we create an invalid point node = node.add_child(fuzz_message(ClientKeyExchangeGenerator(), substitutions=dict((i, 0x00) for i in range(-1, -33, -1)))) node = node.add_child(ChangeCipherSpecGenerator()) node = node.add_child(FinishedGenerator()) node = node.add_child(TCPBufferingDisable()) node = node.add_child(TCPBufferingFlush()) node = node.add_child(ExpectAlert(AlertLevel.fatal, AlertDescription.illegal_parameter)) node = node.add_child(ExpectClose()) conversations["invalid point (self-inconsistent, y all zero)"] = conversation # invalid ecdh_Yc value conversation = Connect(host, port) node = conversation ciphers = [CipherSuite.TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA] ext = {ExtensionType.renegotiation_info: None, ExtensionType.supported_groups: SupportedGroupsExtension(). create([GroupName.secp256r1]), ExtensionType.ec_point_formats: ECPointFormatsExtension(). create([ECPointFormat.uncompressed])} node = node.add_child(ClientHelloGenerator(ciphers, extensions=ext)) ext = {ExtensionType.renegotiation_info: None, ExtensionType.ec_point_formats: None} node = node.add_child(ExpectServerHello(extensions=ext)) node = node.add_child(ExpectCertificate()) node = node.add_child(ExpectServerKeyExchange()) node = node.add_child(ExpectServerHelloDone()) node = node.add_child(TCPBufferingEnable()) # uncompressed EC points need to be self consistent, by changing # one coordinate without changing the other we create an invalid point node = node.add_child(fuzz_message(ClientKeyExchangeGenerator(), xors={-1:0xff})) node = node.add_child(ChangeCipherSpecGenerator()) node = node.add_child(FinishedGenerator()) node = node.add_child(TCPBufferingDisable()) node = node.add_child(TCPBufferingFlush()) node = node.add_child(ExpectAlert(AlertLevel.fatal, AlertDescription.illegal_parameter)) node = node.add_child(ExpectClose()) conversations["invalid point (self-inconsistent)"] = conversation # truncated Client Key Exchange conversation = Connect(host, port) node = conversation ciphers = [CipherSuite.TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA] ext = {ExtensionType.renegotiation_info: None, ExtensionType.supported_groups: SupportedGroupsExtension(). create([GroupName.secp256r1]), ExtensionType.ec_point_formats: ECPointFormatsExtension(). create([ECPointFormat.uncompressed])} node = node.add_child(ClientHelloGenerator(ciphers, extensions=ext)) ext = {ExtensionType.renegotiation_info: None, ExtensionType.ec_point_formats: None} node = node.add_child(ExpectServerHello(extensions=ext)) node = node.add_child(ExpectCertificate()) node = node.add_child(ExpectServerKeyExchange()) node = node.add_child(ExpectServerHelloDone()) node = node.add_child(TCPBufferingEnable()) # uncompressed EC points need to be self consistent, by changing # one coordinate without changing the other we create an invalid point node = node.add_child(truncate_handshake(ClientKeyExchangeGenerator(), 1)) node = node.add_child(ChangeCipherSpecGenerator()) node = node.add_child(FinishedGenerator()) node = node.add_child(TCPBufferingDisable()) node = node.add_child(TCPBufferingFlush()) node = node.add_child(ExpectAlert(AlertLevel.fatal, AlertDescription.decode_error)) node = node.add_child(ExpectClose()) conversations["truncated ecdh_Yc value"] = conversation # padded Client Key Exchange conversation = Connect(host, port) node = conversation ciphers = [CipherSuite.TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA] ext = {ExtensionType.renegotiation_info: None, ExtensionType.supported_groups: SupportedGroupsExtension(). create([GroupName.secp256r1]), ExtensionType.ec_point_formats: ECPointFormatsExtension(). create([ECPointFormat.uncompressed])} node = node.add_child(ClientHelloGenerator(ciphers, extensions=ext)) ext = {ExtensionType.renegotiation_info: None, ExtensionType.ec_point_formats: None} node = node.add_child(ExpectServerHello(extensions=ext)) node = node.add_child(ExpectCertificate()) node = node.add_child(ExpectServerKeyExchange()) node = node.add_child(ExpectServerHelloDone()) node = node.add_child(TCPBufferingEnable()) # uncompressed EC points need to be self consistent, by changing # one coordinate without changing the other we create an invalid point node = node.add_child(pad_handshake(ClientKeyExchangeGenerator(), 1)) node = node.add_child(ChangeCipherSpecGenerator()) node = node.add_child(FinishedGenerator()) node = node.add_child(TCPBufferingDisable()) node = node.add_child(TCPBufferingFlush()) node = node.add_child(ExpectAlert(AlertLevel.fatal, AlertDescription.decode_error)) node = node.add_child(ExpectClose()) conversations["padded Client Key Exchange"] = conversation good = 0 bad = 0 xfail = 0 xpass = 0 failed = [] xpassed = [] if not num_limit: num_limit = len(conversations) # make sure that sanity test is run first and last # to verify that server was running and kept running throughout sanity_tests = [('sanity', conversations['sanity'])] if run_only: if num_limit > len(run_only): num_limit = len(run_only) regular_tests = [(k, v) for k, v in conversations.items() if k in run_only] else: regular_tests = [(k, v) for k, v in conversations.items() if (k != 'sanity') and k not in run_exclude] sampled_tests = sample(regular_tests, min(num_limit, len(regular_tests))) ordered_tests = chain(sanity_tests, sampled_tests, sanity_tests) for c_name, c_test in ordered_tests: if run_only and c_name not in run_only or c_name in run_exclude: continue print("{0} ...".format(c_name)) runner = Runner(c_test) res = True exception = None try: runner.run() except Exception as exp: exception = exp print("Error while processing") print(traceback.format_exc()) res = False if c_name in expected_failures: if res: xpass += 1 xpassed.append(c_name) print("XPASS-expected failure but test passed\n") else: if expected_failures[c_name] is not None and \ expected_failures[c_name] not in str(exception): bad += 1 failed.append(c_name) print("Expected error message: {0}\n" .format(expected_failures[c_name])) else: xfail += 1 print("OK-expected failure\n") else: if res: good += 1 print("OK\n") else: bad += 1 failed.append(c_name) print("Test end") print(20 * '=') print("version: {0}".format(version)) print(20 * '=') print("TOTAL: {0}".format(len(sampled_tests) + 2*len(sanity_tests))) print("SKIP: {0}".format(len(run_exclude.intersection(conversations.keys())))) print("PASS: {0}".format(good)) print("XFAIL: {0}".format(xfail)) print("FAIL: {0}".format(bad)) print("XPASS: {0}".format(xpass)) print(20 * '=') sort = sorted(xpassed ,key=natural_sort_keys) if len(sort): print("XPASSED:\n\t{0}".format('\n\t'.join(repr(i) for i in sort))) sort = sorted(failed, key=natural_sort_keys) if len(sort): print("FAILED:\n\t{0}".format('\n\t'.join(repr(i) for i in sort))) if bad or xpass: sys.exit(1) if __name__ == "__main__": main()