Example #1
0
    def test_check_tcpdump(self):
        mock_call = mock.Mock(spec=subprocess.check_call)

        def raise_error(*args, **kwargs):
            raise subprocess.CalledProcessError(1, "")

        with mock.patch("tlsfuzzer.timing_runner.subprocess.check_call",
                        mock_call) as mock_c:
            ret = TimingRunner.check_tcpdump()
            mock_c.assert_called_once()
            self.assertTrue(ret)
            mock_c.side_effect = raise_error
            ret = TimingRunner.check_tcpdump()
            self.assertFalse(ret)
Example #2
0
    def test_check_analysis_availability(self):
        analysis_present = True
        try:
            from tlsfuzzer.analysis import Analysis
        except ImportError:
            analysis_present = False

        self.assertEqual(TimingRunner.check_analysis_availability(),
                         analysis_present)
Example #3
0
    def test_check_extraction_availability(self):
        extraction_present = True
        try:
            from tlsfuzzer.extract import Extract
        except ImportError:
            extraction_present = False

        self.assertEqual(TimingRunner.check_extraction_availability(),
                         extraction_present)
Example #4
0
def main():
    host = "localhost"
    port = 4433
    num_limit = None
    run_exclude = set()
    expected_failures = {}
    last_exp_tmp = None
    timing = False
    outdir = "/tmp"
    repetitions = 100
    interface = None
    quick = False
    cipher = CipherSuite.TLS_RSA_WITH_AES_128_CBC_SHA
    affinity = None
    ciphertext_len = 512

    argv = sys.argv[1:]
    opts, args = getopt.getopt(
        argv, "h:p:e:x:X:n:l:o:i:C:",
        ["help", "repeat=", "quick", "cpu-list=", "payload-len="])
    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 == '-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 == '-C':
            if arg[:2] == '0x':
                cipher = int(arg, 16)
            else:
                try:
                    cipher = getattr(CipherSuite, arg)
                except AttributeError:
                    cipher = int(arg)
        elif opt == '-n':
            num_limit = int(arg)
        elif opt == '-l':
            level = int(arg)
        elif opt == "-i":
            timing = True
            interface = arg
        elif opt == '-o':
            outdir = arg
        elif opt == "--payload-len":
            ciphertext_len = int(arg)
        elif opt == "--repeat":
            repetitions = int(arg)
        elif opt == '--help':
            help_msg()
            sys.exit(0)
        elif opt == '--quick':
            quick = True
        elif opt == '--cpu-list':
            affinity = arg
        else:
            raise ValueError("Unknown option: {0}".format(opt))

    if args:
        run_only = set(args)
    else:
        run_only = None

    mac_sizes = {
        "md5": 16,
        "sha": 20,
        "sha256": 32,
        "sha384": 48,
    }

    if CipherSuite.canonicalMacName(cipher) not in mac_sizes:
        print("Unsupported MAC, exiting")
        exit(1)

    # group conversations that should have the same timing signature
    if quick:
        groups = {"quick - wrong MAC": {}}
    else:
        groups = {"wrong padding and MAC": {}, "MAC out of bounds": {}}

    dhe = cipher in CipherSuite.ecdhAllSuites
    ext = {}
    ext[ExtensionType.signature_algorithms] = \
        SignatureAlgorithmsExtension().create(SIG_ALL)
    ext[ExtensionType.signature_algorithms_cert] = \
        SignatureAlgorithmsCertExtension().create(SIG_ALL)
    if dhe:
        sup_groups = [GroupName.secp256r1, GroupName.ffdhe2048]
        ext[ExtensionType.supported_groups] = SupportedGroupsExtension() \
            .create(sup_groups)

    # first run sanity test and verify that server supports this ciphersuite
    conversation = Connect(host, port)
    node = conversation
    ciphers = [cipher]
    node = node.add_child(ClientHelloGenerator(ciphers, extensions=ext))
    node = node.add_child(ExpectServerHello())
    node = node.add_child(ExpectCertificate())
    if dhe:
        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(b"GET / HTTP/1.0\r\n\r\n"))
    node = node.add_child(ExpectApplicationData())
    node = node.add_child(
        AlertGenerator(AlertLevel.warning, AlertDescription.close_notify))
    node = node.add_child(
        ExpectAlert(AlertLevel.warning, AlertDescription.close_notify))
    node.next_sibling = ExpectClose()
    node = node.add_child(ExpectClose())
    for group_name in groups:
        groups[group_name]["sanity"] = conversation
    runner = Runner(conversation)
    try:
        runner.run()
    except Exception as exp:
        # Exception means the server rejected the ciphersuite
        print("Failing on {0} because server does not support it. ".format(
            CipherSuite.ietfNames[cipher]))
        print(20 * '=')
        exit(1)

    # assume block length of 16 if not 3des
    block_len = 8 if CipherSuite.canonicalCipherName(cipher) == "3des" else 16
    mac_len = mac_sizes[CipherSuite.canonicalMacName(cipher)]
    invert_mac = {}
    for index in range(0, mac_len):
        invert_mac[index] = 0xff

    if quick:
        # iterate over min/max padding and first/last byte MAC error
        for pad_len, error_pos in product([1, 256], [0, -1]):
            payload_len = ciphertext_len - mac_len - pad_len - block_len

            conversation = Connect(host, port)
            node = conversation
            ciphers = [cipher]
            node = node.add_child(ClientHelloGenerator(ciphers,
                                                       extensions=ext))
            node = node.add_child(ExpectServerHello())
            node = node.add_child(ExpectCertificate())
            if dhe:
                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(
                fuzz_padding(fuzz_mac(ApplicationDataGenerator(
                    bytearray(payload_len)),
                                      xors={error_pos: 0xff}),
                             min_length=pad_len))
            node = node.add_child(
                ExpectAlert(AlertLevel.fatal, AlertDescription.bad_record_mac))
            node = node.add_child(ExpectClose())
            groups["quick - wrong MAC"][
                "wrong MAC at pos {0}, padding length {1}".format(
                    error_pos, pad_len)] = conversation

        # iterate over min/max padding and first/last byte of padding error
        for pad_len, error_pos in product([256], [0, 254]):
            payload_len = ciphertext_len - mac_len - pad_len - block_len

            conversation = Connect(host, port)
            node = conversation
            ciphers = [cipher]
            node = node.add_child(ClientHelloGenerator(ciphers,
                                                       extensions=ext))
            node = node.add_child(ExpectServerHello())
            node = node.add_child(ExpectCertificate())
            if dhe:
                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(
                fuzz_padding(ApplicationDataGenerator(bytearray(payload_len)),
                             min_length=pad_len,
                             xors={(error_pos): 0xff}))
            node = node.add_child(
                ExpectAlert(AlertLevel.fatal, AlertDescription.bad_record_mac))
            node = node.add_child(ExpectClose())
            groups["quick - wrong MAC"][
                "wrong pad at pos {0}, padding length {1}".format(
                    error_pos, pad_len)] = conversation

    else:
        # iterate over: padding length with incorrect MAC
        #               invalid padding length with correct MAC
        for pad_len in range(1, 257):

            # ciphertext 1 has 512 bytes, calculate payload size
            payload_len = ciphertext_len - mac_len - pad_len - block_len

            conversation = Connect(host, port)
            node = conversation
            ciphers = [cipher]
            node = node.add_child(ClientHelloGenerator(ciphers,
                                                       extensions=ext))
            node = node.add_child(ExpectServerHello())
            node = node.add_child(ExpectCertificate())
            if dhe:
                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(
                fuzz_padding(fuzz_mac(ApplicationDataGenerator(
                    bytearray(payload_len)),
                                      xors=invert_mac),
                             min_length=pad_len))
            node = node.add_child(
                ExpectAlert(AlertLevel.fatal, AlertDescription.bad_record_mac))
            node = node.add_child(ExpectClose())
            groups["wrong padding and MAC"][
                "wrong MAC, padding length {0}".format(pad_len)] = conversation

            # incorrect padding of length 255 (256 with the length byte)
            # with error byte iterated over the length of padding

            # avoid changing the padding length byte
            if pad_len < 256:
                payload_len = ciphertext_len - mac_len - 256 - block_len

                conversation = Connect(host, port)
                node = conversation
                ciphers = [cipher]
                node = node.add_child(
                    ClientHelloGenerator(ciphers, extensions=ext))
                node = node.add_child(ExpectServerHello())
                node = node.add_child(ExpectCertificate())
                if dhe:
                    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(
                    fuzz_padding(ApplicationDataGenerator(
                        bytearray(payload_len)),
                                 min_length=256,
                                 xors={(pad_len - 1): 0xff}))
                node = node.add_child(
                    ExpectAlert(AlertLevel.fatal,
                                AlertDescription.bad_record_mac))
                node = node.add_child(ExpectClose())
                groups["wrong padding and MAC"][
                    "padding length 255 (256 with the length byte), padding error at position {0}"
                    .format(pad_len - 1)] = conversation

            # ciphertext 2 has 128 bytes and broken padding to make server check mac "before" the plaintext
            padding = 128 - 1 - block_len - mac_len
            conversation = Connect(host, port)
            node = conversation
            ciphers = [cipher]
            node = node.add_child(ClientHelloGenerator(ciphers,
                                                       extensions=ext))
            node = node.add_child(ExpectServerHello())
            node = node.add_child(ExpectCertificate())
            if dhe:
                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(
                fuzz_padding(ApplicationDataGenerator(bytearray(1)),
                             substitutions={
                                 -1: pad_len - 1,
                                 0: 0
                             },
                             min_length=padding))
            node = node.add_child(
                ExpectAlert(AlertLevel.fatal, AlertDescription.bad_record_mac))
            node = node.add_child(ExpectClose())
            groups["MAC out of bounds"]["padding length byte={0}".format(
                pad_len - 1)] = conversation

        # iterate over MAC length and fuzz byte by byte
        payload_len = ciphertext_len - mac_len - block_len - 256
        for mac_index in range(0, mac_len):
            conversation = Connect(host, port)
            node = conversation
            ciphers = [cipher]
            node = node.add_child(ClientHelloGenerator(ciphers,
                                                       extensions=ext))
            node = node.add_child(ExpectServerHello())
            node = node.add_child(ExpectCertificate())
            if dhe:
                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(
                fuzz_padding(fuzz_mac(ApplicationDataGenerator(
                    bytearray(payload_len)),
                                      xors={mac_index: 0xff}),
                             min_length=256))
            node = node.add_child(
                ExpectAlert(AlertLevel.fatal, AlertDescription.bad_record_mac))
            node = node.add_child(ExpectClose())
            groups["wrong padding and MAC"][
                "padding length 255 (256 with the length byte), incorrect MAC at pos {0}"
                .format(mac_index)] = conversation

    for group_name, conversations in groups.items():

        # run the 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)
        if not sampled_tests:
            continue

        print("Running tests for {0}".format(CipherSuite.ietfNames[cipher]))

        for c_name, c_test in ordered_tests:
            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("Lucky 13 attack check for {0} {1}".format(
            group_name, CipherSuite.ietfNames[cipher]))

        print("Test end")
        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)
        elif timing:
            # if regular tests passed, run timing collection and analysis
            if TimingRunner.check_tcpdump():
                timing_runner = TimingRunner(
                    "{0}_v{1}_{2}_{3}".format(sys.argv[0], version, group_name,
                                              CipherSuite.ietfNames[cipher]),
                    sampled_tests, outdir, host, port, interface, affinity)
                print("Running timing tests...")
                timing_runner.generate_log(run_only, run_exclude, repetitions)
                ret_val = timing_runner.run()
                print("Statistical analysis exited with {0}".format(ret_val))
            else:
                print(
                    "Could not run timing tests because tcpdump is not present!"
                )
                sys.exit(1)
            print(20 * '=')
def main():
    """Check if server is not vulnerable to Bleichenbacher attack"""
    host = "localhost"
    port = 4433
    num_limit = None
    run_exclude = set()
    expected_failures = {}
    last_exp_tmp = None
    timeout = 1.0
    alert = AlertDescription.bad_record_mac
    level = AlertLevel.fatal
    srv_extensions = {ExtensionType.renegotiation_info: None}
    no_sni = False
    repetitions = 100
    interface = None
    timing = False
    outdir = "/tmp"
    cipher = CipherSuite.TLS_RSA_WITH_AES_128_CBC_SHA
    affinity = None

    argv = sys.argv[1:]
    opts, args = getopt.getopt(argv,
                               "h:p:e:x:X:t:n:a:l:l:o:i:C:",
                               ["help",
                                "no-safe-renego",
                                "no-sni",
                                "repeat=",
                                "cpu-list="])
    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 == '-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 == '-n':
            num_limit = int(arg)
        elif opt == '-C':
            if arg[:2] == '0x':
                cipher = int(arg, 16)
            else:
                try:
                    cipher = getattr(CipherSuite, arg)
                except AttributeError:
                    cipher = int(arg)
        elif opt == '-t':
            timeout = float(arg)
        elif opt == '-a':
            alert = int(arg)
        elif opt == '-l':
            level = int(arg)
        elif opt == "-i":
            timing = True
            interface = arg
        elif opt == '-o':
            outdir = arg
        elif opt == "--repeat":
            repetitions = int(arg)
        elif opt == "--no-safe-renego":
            srv_extensions = None
        elif opt == "--no-sni":
            no_sni = True
        elif opt == "--cpu-list":
            affinity = 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

    cln_extensions = {ExtensionType.renegotiation_info: None}
    if is_valid_hostname(host) and not no_sni:
        cln_extensions[ExtensionType.server_name] = \
            SNIExtension().create(bytearray(host, 'ascii'))

    # RSA key exchange check
    if cipher not in CipherSuite.certSuites:
        print("Ciphersuite has to use RSA key exchange.")
        exit(1)

    conversations = OrderedDict()

    conversation = Connect(host, port)
    node = conversation
    ciphers = [cipher]
    node = node.add_child(ClientHelloGenerator(ciphers,
                                               extensions=cln_extensions))
    node = node.add_child(ExpectServerHello(extensions=srv_extensions))
    node = node.add_child(ExpectCertificate())
    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\r\n\r\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()
    node = node.add_child(ExpectClose())
    conversations["sanity"] = conversation

    runner = Runner(conversation)
    try:
        runner.run()
    except Exception as exp:
        # Exception means the server rejected the ciphersuite
        print("Failing on {0} because server does not support it. ".format(CipherSuite.ietfNames[cipher]))
        print(20 * '=')
        exit(1)

    # check if a certain number doesn't trip up the server
    # (essentially a second sanity test)
    conversation = Connect(host, port)
    node = conversation
    ciphers = [cipher]
    node = node.add_child(ClientHelloGenerator(ciphers,
                                               extensions=cln_extensions))
    node = node.add_child(ExpectServerHello(extensions=srv_extensions))

    node = node.add_child(ExpectCertificate())
    node = node.add_child(ExpectServerHelloDone())
    node = node.add_child(ClientKeyExchangeGenerator(padding_subs={2: 1}))
    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\r\n\r\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()
    node = node.add_child(ExpectClose())

    conversations["sanity - static non-zero byte in random padding"] = conversation

    # first put tests that are the benchmark to be compared to
    # fuzz MAC in the Finshed message to make decryption fail
    conversation = Connect(host, port)
    node = conversation
    ciphers = [cipher]
    node = node.add_child(ClientHelloGenerator(ciphers,
                                               extensions=cln_extensions))
    node = node.add_child(ExpectServerHello(extensions=srv_extensions))

    node = node.add_child(ExpectCertificate())
    node = node.add_child(ExpectServerHelloDone())
    node = node.add_child(TCPBufferingEnable())
    node = node.add_child(ClientKeyExchangeGenerator())
    node = node.add_child(ChangeCipherSpecGenerator())
    node = node.add_child(fuzz_mac(FinishedGenerator(), xors={0:0xff}))
    node = node.add_child(TCPBufferingDisable())
    node = node.add_child(TCPBufferingFlush())
    node = node.add_child(ExpectAlert(level,
                                      alert))
    node.add_child(ExpectClose())

    conversations["invalid MAC in Finished on pos 0"] = conversation

    conversation = Connect(host, port)
    node = conversation
    ciphers = [cipher]
    node = node.add_child(ClientHelloGenerator(ciphers,
                                               extensions=cln_extensions))
    node = node.add_child(ExpectServerHello(extensions=srv_extensions))

    node = node.add_child(ExpectCertificate())
    node = node.add_child(ExpectServerHelloDone())
    node = node.add_child(TCPBufferingEnable())
    node = node.add_child(ClientKeyExchangeGenerator())
    node = node.add_child(ChangeCipherSpecGenerator())
    node = node.add_child(fuzz_mac(FinishedGenerator(), xors={-1:0xff}))
    node = node.add_child(TCPBufferingDisable())
    node = node.add_child(TCPBufferingFlush())
    node = node.add_child(ExpectAlert(level,
                                      alert))
    node.add_child(ExpectClose())

    conversations["invalid MAC in Finished on pos -1"] = conversation

    # and for good measure, add something that sends invalid padding
    conversation = Connect(host, port)
    node = conversation
    ciphers = [cipher]
    node = node.add_child(ClientHelloGenerator(ciphers,
                                               extensions=cln_extensions))
    node = node.add_child(ExpectServerHello(extensions=srv_extensions))

    node = node.add_child(ExpectCertificate())
    node = node.add_child(ExpectServerHelloDone())
    node = node.add_child(TCPBufferingEnable())
    node = node.add_child(ClientKeyExchangeGenerator())
    node = node.add_child(ChangeCipherSpecGenerator())
    node = node.add_child(fuzz_padding(FinishedGenerator(),
                                       xors={-1:0xff, -2:0x01}))
    node = node.add_child(TCPBufferingDisable())
    node = node.add_child(TCPBufferingFlush())
    node = node.add_child(ExpectAlert(level,
                                      alert))
    node.add_child(ExpectClose())

    conversations["invalid padding_length in Finished"] = conversation

    # create a CKE with PMS the runner doesn't know/use
    conversation = Connect(host, port)
    node = conversation
    ciphers = [cipher]
    node = node.add_child(ClientHelloGenerator(ciphers,
                                               extensions=cln_extensions))
    node = node.add_child(ExpectServerHello(extensions=srv_extensions))

    node = node.add_child(ExpectCertificate())
    node = node.add_child(ExpectServerHelloDone())
    node = node.add_child(TCPBufferingEnable())
    # use too short PMS but then change padding so that the PMS is
    # correct length with correct TLS version but the encryption keys
    # that tlsfuzzer calculates will be incorrect
    node = node.add_child(ClientKeyExchangeGenerator(
        padding_subs={-3: 0, -2: 3, -1: 3},
        premaster_secret=bytearray([1] * 46)))
    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(level,
                                      alert))
    node.add_child(ExpectClose())

    conversations["fuzzed pre master secret"] = conversation

    # set 2nd byte of padding to 3 (invalid value)
    conversation = Connect(host, port)
    node = conversation
    ciphers = [cipher]
    node = node.add_child(ClientHelloGenerator(ciphers,
                                               extensions=cln_extensions))
    node = node.add_child(ExpectServerHello(extensions=srv_extensions))

    node = node.add_child(ExpectCertificate())
    node = node.add_child(ExpectServerHelloDone())
    node = node.add_child(TCPBufferingEnable())
    node = node.add_child(ClientKeyExchangeGenerator(padding_subs={1: 3}))
    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(level,
                                      alert))
    node.add_child(ExpectClose())

    conversations["set PKCS#1 padding type to 3"] = conversation

    # set 2nd byte of padding to 1 (signing)
    conversation = Connect(host, port)
    node = conversation
    ciphers = [cipher]
    node = node.add_child(ClientHelloGenerator(ciphers,
                                               extensions=cln_extensions))
    node = node.add_child(ExpectServerHello(extensions=srv_extensions))

    node = node.add_child(ExpectCertificate())
    node = node.add_child(ExpectServerHelloDone())
    node = node.add_child(TCPBufferingEnable())
    node = node.add_child(ClientKeyExchangeGenerator(padding_subs={1: 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(level,
                                      alert))
    node.add_child(ExpectClose())

    conversations["set PKCS#1 padding type to 1"] = conversation

    # test early zero in random data
    conversation = Connect(host, port)
    node = conversation
    ciphers = [cipher]
    node = node.add_child(ClientHelloGenerator(ciphers,
                                               extensions=cln_extensions))
    node = node.add_child(ExpectServerHello(extensions=srv_extensions))

    node = node.add_child(ExpectCertificate())
    node = node.add_child(ExpectServerHelloDone())
    node = node.add_child(TCPBufferingEnable())
    node = node.add_child(ClientKeyExchangeGenerator(padding_subs={4: 0}))
    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(level,
                                      alert))
    node.add_child(ExpectClose())

    conversations["zero byte in random padding"] = conversation

    # check if early padding separator is detected
    conversation = Connect(host, port)
    node = conversation
    ciphers = [cipher]
    node = node.add_child(ClientHelloGenerator(ciphers,
                                               extensions=cln_extensions))
    node = node.add_child(ExpectServerHello(extensions=srv_extensions))

    node = node.add_child(ExpectCertificate())
    node = node.add_child(ExpectServerHelloDone())
    node = node.add_child(TCPBufferingEnable())
    node = node.add_child(ClientKeyExchangeGenerator(padding_subs={-2: 0}))
    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(level,
                                      alert))
    node.add_child(ExpectClose())

    conversations["zero byte in last byte of random padding"] = conversation

    # check if separator without any random padding is detected
    conversation = Connect(host, port)
    node = conversation
    ciphers = [cipher]
    node = node.add_child(ClientHelloGenerator(ciphers,
                                               extensions=cln_extensions))
    node = node.add_child(ExpectServerHello(extensions=srv_extensions))

    node = node.add_child(ExpectCertificate())
    node = node.add_child(ExpectServerHelloDone())
    node = node.add_child(TCPBufferingEnable())
    node = node.add_child(ClientKeyExchangeGenerator(padding_subs={2: 0}))
    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(level,
                                      alert))
    node.add_child(ExpectClose())

    conversations["zero byte in first byte of random padding"] = conversation

    # check if invalid first byte of encoded value is correctly detecte
    conversation = Connect(host, port)
    node = conversation
    ciphers = [cipher]
    node = node.add_child(ClientHelloGenerator(ciphers,
                                               extensions=cln_extensions))
    node = node.add_child(ExpectServerHello(extensions=srv_extensions))

    node = node.add_child(ExpectCertificate())
    node = node.add_child(ExpectServerHelloDone())
    node = node.add_child(TCPBufferingEnable())
    node = node.add_child(ClientKeyExchangeGenerator(padding_subs={0: 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(level,
                                      alert))
    node.add_child(ExpectClose())

    conversations["invalid version number in padding"] = conversation

    # check if no null separator in padding is detected
    conversation = Connect(host, port)
    node = conversation
    ciphers = [cipher]
    node = node.add_child(ClientHelloGenerator(ciphers,
                                               extensions=cln_extensions))
    node = node.add_child(ExpectServerHello(extensions=srv_extensions))

    node = node.add_child(ExpectCertificate())
    node = node.add_child(ExpectServerHelloDone())
    node = node.add_child(TCPBufferingEnable())
    node = node.add_child(ClientKeyExchangeGenerator(padding_subs={-1: 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(level,
                                      alert))
    node.add_child(ExpectClose())

    conversations["no null separator in padding"] = conversation

    # check if no null separator in padding is detected
    # but with PMS set to non-zero
    conversation = Connect(host, port)
    node = conversation
    ciphers = [cipher]
    node = node.add_child(ClientHelloGenerator(ciphers,
                                               extensions=cln_extensions))
    node = node.add_child(ExpectServerHello(extensions=srv_extensions))

    node = node.add_child(ExpectCertificate())
    node = node.add_child(ExpectServerHelloDone())
    node = node.add_child(TCPBufferingEnable())
    node = node.add_child(ClientKeyExchangeGenerator(padding_subs={-1: 1},
                                                     premaster_secret=bytearray([1] * 48)))
    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(level,
                                      alert))
    node.add_child(ExpectClose())

    conversations["no null separator in encrypted value"] = conversation

    # check if too short PMS is detected
    conversation = Connect(host, port)
    node = conversation
    ciphers = [cipher]
    node = node.add_child(ClientHelloGenerator(ciphers,
                                               extensions=cln_extensions))
    node = node.add_child(ExpectServerHello(extensions=srv_extensions))

    node = node.add_child(ExpectCertificate())
    node = node.add_child(ExpectServerHelloDone())
    node = node.add_child(TCPBufferingEnable())
    node = node.add_child(ClientKeyExchangeGenerator(premaster_secret=bytearray([1, 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(level,
                                      alert))
    node.add_child(ExpectClose())

    conversations["two byte long PMS (TLS version only)"] = conversation

    # check if no encrypted payload is detected
    conversation = Connect(host, port)
    node = conversation
    ciphers = [cipher]
    node = node.add_child(ClientHelloGenerator(ciphers,
                                               extensions=cln_extensions))
    node = node.add_child(ExpectServerHello(extensions=srv_extensions))

    node = node.add_child(ExpectCertificate())
    node = node.add_child(ExpectServerHelloDone())
    node = node.add_child(TCPBufferingEnable())
    # the TLS version is always set, so we mask the real padding separator
    # and set the last byte of PMS to 0
    node = node.add_child(ClientKeyExchangeGenerator(padding_subs={-1: 1},
                                                     premaster_secret=bytearray([1, 1, 0])))
    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(level,
                                      alert))
    node.add_child(ExpectClose())

    conversations["no encrypted value"] = conversation

    # check if too short encrypted payload is detected
    conversation = Connect(host, port)
    node = conversation
    ciphers = [cipher]
    node = node.add_child(ClientHelloGenerator(ciphers,
                                               extensions=cln_extensions))
    node = node.add_child(ExpectServerHello(extensions=srv_extensions))

    node = node.add_child(ExpectCertificate())
    node = node.add_child(ExpectServerHelloDone())
    node = node.add_child(TCPBufferingEnable())
    # the TLS version is always set, so we mask the real padding separator
    # and set the last byte of PMS to 0
    node = node.add_child(ClientKeyExchangeGenerator(padding_subs={-1: 1},
                                                     premaster_secret=bytearray([1, 1, 0, 3])))
    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(level,
                                      alert))
    node.add_child(ExpectClose())

    conversations["one byte encrypted value"] = conversation

    # check if too short PMS is detected
    conversation = Connect(host, port)
    node = conversation
    ciphers = [cipher]
    node = node.add_child(ClientHelloGenerator(ciphers,
                                               extensions=cln_extensions))
    node = node.add_child(ExpectServerHello(extensions=srv_extensions))

    node = node.add_child(ExpectCertificate())
    node = node.add_child(ExpectServerHelloDone())
    node = node.add_child(TCPBufferingEnable())
    node = node.add_child(ClientKeyExchangeGenerator(premaster_secret=bytearray([1] * 47)))
    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(level,
                                      alert))
    node.add_child(ExpectClose())

    conversations["too short (47-byte) pre master secret"] = conversation

    # check if too short PMS is detected
    conversation = Connect(host, port)
    node = conversation
    ciphers = [cipher]
    node = node.add_child(ClientHelloGenerator(ciphers,
                                               extensions=cln_extensions))
    node = node.add_child(ExpectServerHello(extensions=srv_extensions))

    node = node.add_child(ExpectCertificate())
    node = node.add_child(ExpectServerHelloDone())
    node = node.add_child(TCPBufferingEnable())
    node = node.add_child(ClientKeyExchangeGenerator(premaster_secret=bytearray([1] * 4)))
    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(level,
                                      alert))
    node.add_child(ExpectClose())

    conversations["very short (4-byte) pre master secret"] = conversation

    # check if too long PMS is detected
    conversation = Connect(host, port)
    node = conversation
    ciphers = [cipher]
    node = node.add_child(ClientHelloGenerator(ciphers,
                                               extensions=cln_extensions))
    node = node.add_child(ExpectServerHello(extensions=srv_extensions))

    node = node.add_child(ExpectCertificate())
    node = node.add_child(ExpectServerHelloDone())
    node = node.add_child(TCPBufferingEnable())
    node = node.add_child(ClientKeyExchangeGenerator(premaster_secret=bytearray([1] * 49)))
    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(level,
                                      alert))
    node.add_child(ExpectClose())

    conversations["too long (49-byte) pre master secret"] = conversation

    # check if very long PMS is detected
    conversation = Connect(host, port)
    node = conversation
    ciphers = [cipher]
    node = node.add_child(ClientHelloGenerator(ciphers,
                                               extensions=cln_extensions))
    node = node.add_child(ExpectServerHello(extensions=srv_extensions))

    node = node.add_child(ExpectCertificate())
    node = node.add_child(ExpectServerHelloDone())
    node = node.add_child(TCPBufferingEnable())
    node = node.add_child(ClientKeyExchangeGenerator(premaster_secret=bytearray([1] * 124)))
    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(level,
                                      alert))
    node.add_child(ExpectClose())

    conversations["very long (124-byte) pre master secret"] = conversation

    conversation = Connect(host, port)
    node = conversation
    ciphers = [cipher]
    node = node.add_child(ClientHelloGenerator(ciphers,
                                               extensions=cln_extensions))
    node = node.add_child(ExpectServerHello(extensions=srv_extensions))

    node = node.add_child(ExpectCertificate())
    node = node.add_child(ExpectServerHelloDone())
    node = node.add_child(TCPBufferingEnable())
    node = node.add_child(ClientKeyExchangeGenerator(premaster_secret=bytearray([1] * 96)))
    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(level,
                                      alert))
    node.add_child(ExpectClose())

    conversations["very long (96-byte) pre master secret"] = conversation

    # check if wrong TLS version number is rejected
    conversation = Connect(host, port)
    node = conversation
    ciphers = [cipher]
    node = node.add_child(ClientHelloGenerator(ciphers,
                                               extensions=cln_extensions))
    node = node.add_child(ExpectServerHello(extensions=srv_extensions))

    node = node.add_child(ExpectCertificate())
    node = node.add_child(ExpectServerHelloDone())
    node = node.add_child(TCPBufferingEnable())
    node = node.add_child(ClientKeyExchangeGenerator(client_version=(2, 2)))
    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(level,
                                      alert))
    node.add_child(ExpectClose())

    conversations["wrong TLS version (2, 2) in pre master secret"] = conversation

    # check if wrong TLS version number is rejected
    conversation = Connect(host, port)
    node = conversation
    ciphers = [cipher]
    node = node.add_child(ClientHelloGenerator(ciphers,
                                               extensions=cln_extensions))
    node = node.add_child(ExpectServerHello(extensions=srv_extensions))

    node = node.add_child(ExpectCertificate())
    node = node.add_child(ExpectServerHelloDone())
    node = node.add_child(TCPBufferingEnable())
    node = node.add_child(ClientKeyExchangeGenerator(client_version=(0, 0)))
    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(level,
                                      alert))
    node.add_child(ExpectClose())

    conversations["wrong TLS version (0, 0) in pre master secret"] = conversation

    # check if too short PKCS padding is detected
    conversation = Connect(host, port)
    node = conversation
    ciphers = [cipher]
    node = node.add_child(ClientHelloGenerator(ciphers,
                                               extensions=cln_extensions))
    node = node.add_child(ExpectServerHello(extensions=srv_extensions))

    node = node.add_child(ExpectCertificate())
    node = node.add_child(ExpectServerHelloDone())
    node = node.add_child(TCPBufferingEnable())
    # move the start of the padding forward, essentially encrypting two 0 bytes
    # at the beginning of the padding, but since those are transformed into a number
    # their existence is lost and it just like the padding was too small
    node = node.add_child(ClientKeyExchangeGenerator(padding_subs={1: 0, 2: 2}))
    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(level,
                                      alert))
    node.add_child(ExpectClose())

    conversations["too short PKCS padding"] = conversation

    # check if very short PKCS padding doesn't have a different behaviour
    conversation = Connect(host, port)
    node = conversation
    ciphers = [cipher]
    node = node.add_child(ClientHelloGenerator(ciphers,
                                               extensions=cln_extensions))
    node = node.add_child(ExpectServerHello(extensions=srv_extensions))

    node = node.add_child(ExpectCertificate())
    node = node.add_child(ExpectServerHelloDone())
    node = node.add_child(TCPBufferingEnable())
    # move the start of the padding 40 bytes towards LSB
    subs = {}
    for i in range(41):
        subs[i] = 0
    subs[41] = 2
    node = node.add_child(ClientKeyExchangeGenerator(padding_subs=subs))
    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(level,
                                      alert))
    node.add_child(ExpectClose())

    conversations["very short PKCS padding (40 bytes short)"] = conversation

    # check if too long PKCS padding is detected
    conversation = Connect(host, port)
    node = conversation
    ciphers = [cipher]
    node = node.add_child(ClientHelloGenerator(ciphers,
                                               extensions=cln_extensions))
    node = node.add_child(ExpectServerHello(extensions=srv_extensions))

    node = node.add_child(ExpectCertificate())
    node = node.add_child(ExpectServerHelloDone())
    node = node.add_child(TCPBufferingEnable())
    # move the start of the padding backward, essentially encrypting no 0 bytes
    # at the beginning of the padding, but since those are transformed into a number
    # its lack is lost and it just like the padding was too big
    node = node.add_child(ClientKeyExchangeGenerator(padding_subs={0: 2}))
    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(level,
                                      alert))
    node.add_child(ExpectClose())

    conversations["too long PKCS padding"] = conversation

    # run the 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]
    if num_limit < len(conversations):
        sampled_tests = sample(regular_tests, min(num_limit, len(regular_tests)))
    else:
        sampled_tests = regular_tests
    ordered_tests = chain(sanity_tests, sampled_tests, sanity_tests)

    print("Running tests for {0}".format(CipherSuite.ietfNames[cipher]))

    for c_name, c_test in ordered_tests:
        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("""Tests for handling of malformed encrypted values in CKE

This test script checks if the server correctly handles malformed
Client Key Exchange messages in RSA key exchange.
When executed with `-i` it will also verify that different errors
are rejected in the same amount of time; it checks for timing
sidechannel.
The script executes tests without \"sanity\" in name multiple
times to estimate server response time.

Quick reminder: when encrypting a value using PKCS#1 v1.5 standard
the plaintext has the following structure, starting from most
significant byte:
- one byte, the version of the encryption, must be 0
- one byte, the type of encryption, must be 2 (is 1 in case of
  signature)
- one or more bytes of random padding, with no zero bytes. The
  count must equal the byte size of the public key modulus less
  size of encrypted value and 3 (for version, type and separator)
  For signatures the bytes must equal 0xff
- one zero byte that acts as separator between padding and
  encrypted value
- one or more bytes that are the encrypted value, for TLS it must
  be 48 bytes long and the first two bytes need to equal the
  TLS version advertised in Client Hello

All tests should exhibit the same kind of timing behaviour, but
if some groups of tests are inconsistent, that points to likely
place where the timing leak happens:
- the control group, lack of consistency here points to Lucky 13:
  - 'invalid MAC in Finished on pos 0'
  - 'invalid MAC in Finished on pos -1'
  - 'fuzzed pre master secret' - this will end up with random
    plaintexts in record with Finished, most resembling a randomly
    selected PMS by the server
  verification:
  - 'set PKCS#1 padding type to 3'
  - 'set PKCS#1 padding type to 1'
- incorrect size of encrypted value (pre-master secret),
  inconsistent results here suggests that the decryption leaks
  length of plaintext:
  - 'zero byte in random padding' - this creates a PMS that's 4
    bytes shorter than the public key size and has a random TLS
    version
  - 'zero byte in last byte of random padding' - this creates a
    PMS that's one byte too long (49 bytes long), with a TLS
    version that's (0, major_version)
  - 'no null separator in padding' - as the PMS is all zero, this
    effectively sends a PMS that's 45 bytes long with TLS version
    of (0, 0)
  - 'two byte long PMS (TLS version only)'
  - 'one byte encrypted value' - the encrypted value is 3, as a
    correct value for first byte of TLS version
  - 'too short (47-byte) pre master secret'
  - 'very short (4-byte) pre master secret'
  - 'too long (49-byte) pre master secret'
  - 'very long (124-byte) pre master secret'
  - 'very long (96-byte) pre master secret'
- invalid PKCS#1 v1.5 encryption padding:
  - 'zero byte in first byte of random padding' - this is a mix
    of too long PMS and invalid padding, it actually doesn't send
    padding at all, the padding length is zero
  - 'invalid version number in padding' - this sets the first byte
    of plaintext to 1
  - 'no null separator in encrypted value' - this doesn't send a
    null byte separating padding and encrypted value
  - 'no encrypted value' - this sends a null separator, but it's
    the last byte of plaintext
  - 'too short PKCS padding' - this sends the correct encryption
    type in the padding (2), but one byte later than required
  - 'very short PKCS padding (40 bytes short)' - same as above
    only 40 bytes later
  - 'too long PKCS padding' this doesn't send the PKCS#1 v1.5
    version at all, but starts with padding type
- invalid TLS version in PMS, differences here suggest a leak in
  code checking for correctness of this value:
  - 'wrong TLS version (2, 2) in pre master secret'
  - 'wrong TLS version (0, 0) in pre master secret'""")
    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 > 0:
        sys.exit(1)
    elif timing:
        # if regular tests passed, run timing collection and analysis
        if TimingRunner.check_tcpdump():
            timing_runner = TimingRunner("{0}_{1}".format(sys.argv[0],
                                                          CipherSuite.ietfNames[cipher]),
                                         sampled_tests,
                                         outdir,
                                         host,
                                         port,
                                         interface,
                                         affinity)
            print("Running timing tests...")
            timing_runner.generate_log(run_only, run_exclude, repetitions)
            ret_val = timing_runner.run()
            if ret_val == 0:
                print("No statistically significant difference detected")
            elif ret_val == 1:
                print("Statisticaly significant difference detected at alpha="
                      "0.05")
            else:
                print("Statistical analysis exited with {0}".format(ret_val))
        else:
            print("Could not run timing tests because tcpdump is not present!")
            sys.exit(1)
        print(20 * '=')
Example #6
0
 def test__format_seconds_with_days(self):
     self.assertEqual(TimingRunner._format_seconds(24 * 60 * 60 * 2),
                      "2d 0h 0m 0.00s")
Example #7
0
 def test__format_seconds_with_hours(self):
     self.assertEqual(TimingRunner._format_seconds(60 * 60), "1h 0m 0.00s")
Example #8
0
 def test__format_seconds_with_minutes(self):
     self.assertEqual(TimingRunner._format_seconds(60 * 35), "35m 0.00s")
Example #9
0
 def test__format_seconds_with_seconds(self):
     self.assertEqual(TimingRunner._format_seconds(12.5), "12.50s")
Example #10
0
 def setUp(self):
     with mock.patch('tlsfuzzer.timing_runner.os.mkdir'):
         with mock.patch(
                 'tlsfuzzer.timing_runner.TimingRunner.check_tcpdump'):
             self.runner = TimingRunner("test", [], "/outdir", "localhost",
                                        4433, "lo")
Example #11
0
class TestRunner(unittest.TestCase):
    def setUp(self):
        with mock.patch('tlsfuzzer.timing_runner.os.mkdir'):
            with mock.patch(
                    'tlsfuzzer.timing_runner.TimingRunner.check_tcpdump'):
                self.runner = TimingRunner("test", [], "/outdir", "localhost",
                                           4433, "lo")

    @staticmethod
    def _mock_open(*args, **kwargs):
        """Fix mock not supporting iterators in all Python versions."""
        mock_open = mock.mock_open(*args, **kwargs)
        mock_open.return_value.__iter__ = lambda s: iter(s.readline, '')
        return mock_open

    def test_init_without_tcpdump(self):
        mock_check = mock.Mock()
        mock_check.return_value = False
        with mock.patch('tlsfuzzer.timing_runner.os.mkdir'):
            with mock.patch(
                    'tlsfuzzer.timing_runner.TimingRunner.check_tcpdump',
                    mock_check):
                self.assertRaises(Exception, TimingRunner, "test", [],
                                  "/outdir", "localhost", 4433, "lo")

    def test_check_tcpdump(self):
        mock_call = mock.Mock(spec=subprocess.check_call)

        def raise_error(*args, **kwargs):
            raise subprocess.CalledProcessError(1, "")

        with mock.patch("tlsfuzzer.timing_runner.subprocess.check_call",
                        mock_call) as mock_c:
            ret = TimingRunner.check_tcpdump()
            mock_c.assert_called_once()
            self.assertTrue(ret)
            mock_c.side_effect = raise_error
            ret = TimingRunner.check_tcpdump()
            self.assertFalse(ret)

    def test_sniff(self):
        self.runner.tcpdump_running = False

        mock_popen = mock.Mock(spec=subprocess.Popen)
        mock_popen.return_value.stderr = io.BytesIO(b"listening\n")
        with mock.patch("tlsfuzzer.timing_runner.subprocess.Popen",
                        mock_popen):
            self.runner.sniff()
            self.assertTrue(self.runner.tcpdump_running)

            mock_popen.return_value.stderr = io.BytesIO(b"\n")
            self.assertRaises(SystemExit, self.runner.sniff)
            self.assertFalse(self.runner.tcpdump_running)

    def test_tcpdump_status(self):
        mock_popen = mock.Mock(spec=subprocess.Popen)
        mock_popen.communicate.return_value = ("", b"Error")
        mock_popen.returncode = 1

        self.runner.tcpdump_running = True
        self.runner.tcpdump_status(mock_popen)
        self.assertFalse(self.runner.tcpdump_running)

        self.runner.tcpdump_running = False
        self.runner.tcpdump_status(mock_popen)
        self.assertFalse(self.runner.tcpdump_running)

    def test_generate_log_sanity(self):
        self.runner.tests = [("sanity", None), ("regular", None)]
        with mock.patch('__main__.__builtins__.open',
                        mock.mock_open()) as mock_file:
            self.runner.generate_log(set(), set(), 10)
            self.assertEqual(self.runner.log.classes, ["regular"])
            self.assertEqual(self.runner.tests, {"regular": None})
            self.assertEqual(mock_file.return_value.write.call_count, 11)

    def test_generate_log_exclusion(self):
        self.runner.tests = [("regular", None), ("exclude", None)]
        with mock.patch('__main__.__builtins__.open',
                        mock.mock_open()) as mock_file:
            self.runner.generate_log(set(), set(["exclude"]), 10)
            self.assertEqual(self.runner.log.classes, ["regular"])
            self.assertEqual(mock_file.return_value.write.call_count, 11)

    def test_generate_log_run_only(self):
        self.runner.tests = [("regular", None), ("exclude", None)]
        with mock.patch('__main__.__builtins__.open',
                        mock.mock_open()) as mock_file:
            self.runner.generate_log(set(["regular"]), set(), 10)
            self.assertEqual(self.runner.log.classes, ["regular"])
            self.assertEqual(mock_file.return_value.write.call_count, 11)

    def test_create_dir(self):
        with mock.patch('tlsfuzzer.timing_runner.os.mkdir') as mock_mkdir:
            TimingRunner("test", [], "/outdir", "localhost", 4433, "lo")
            mock_mkdir.assert_called_once()

    def test_check_extraction_availability(self):
        extraction_present = True
        try:
            from tlsfuzzer.extract import Extract
        except ImportError:
            extraction_present = False

        self.assertEqual(TimingRunner.check_extraction_availability(),
                         extraction_present)

    def test_check_analysis_availability(self):
        analysis_present = True
        try:
            from tlsfuzzer.analysis import Analysis
        except ImportError:
            analysis_present = False

        self.assertEqual(TimingRunner.check_analysis_availability(),
                         analysis_present)

    def test_extract(self):
        check_extract = mock.Mock()
        check_extract.return_value = False

        with mock.patch(
                "tlsfuzzer.timing_runner.TimingRunner.check_extraction_availability",
                check_extract):
            self.assertFalse(self.runner.extract())

        self.runner.log = mock.Mock(autospec=True)
        with mock.patch("__main__.__builtins__.__import__"):
            self.assertTrue(self.runner.extract())

    def test_analyse(self):
        check_analysis = mock.Mock()
        check_analysis.return_value = False

        with mock.patch(
                "tlsfuzzer.timing_runner.TimingRunner.check_analysis_availability",
                check_analysis):
            self.assertEqual(self.runner.analyse(), 2)

        self.runner.log = mock.Mock(autospec=True)
        with mock.patch("__main__.__builtins__.__import__"):
            self.assertNotEqual(self.runner.analyse(), 2)

    def test_run(self):
        self.runner.tests = {"A": None, "B": None, "C": None}
        self.runner.tcpdump_running = True
        analyse = mock.Mock()
        analyse.return_value = 1
        with mock.patch(
                '__main__.__builtins__.open',
                self._mock_open(
                    read_data="A,B,C\r\n0,2,1\r\n2,0,1\r\n2,1,0\r\n")):
            with mock.patch('tlsfuzzer.timing_runner.TimingRunner.sniff'):
                with mock.patch('tlsfuzzer.timing_runner.TimingRunner.extract'
                                ) as extract:
                    with mock.patch(
                            'tlsfuzzer.timing_runner.TimingRunner.analyse',
                            analyse):
                        with mock.patch('tlsfuzzer.timing_runner.Thread'):
                            with mock.patch(
                                    'tlsfuzzer.timing_runner.time.sleep'):
                                with mock.patch(
                                        'tlsfuzzer.timing_runner.Runner'
                                ) as runner:
                                    ret = self.runner.run()
                                    self.assertEqual(runner.call_count,
                                                     WARM_UP + 9)
                                    extract.assert_called_once()
                                    analyse.assert_called_once()
                                    self.assertEqual(ret, 1)

    def test_run_no_extraction(self):
        self.runner.tests = {"A": None, "B": None, "C": None}
        self.runner.tcpdump_running = True
        extract = mock.Mock()
        extract.return_value = False
        with mock.patch(
                '__main__.__builtins__.open',
                self._mock_open(
                    read_data="A,B,C\r\n0,2,1\r\n2,0,1\r\n2,1,0\r\n")):
            with mock.patch('tlsfuzzer.timing_runner.TimingRunner.sniff'):
                with mock.patch('tlsfuzzer.timing_runner.TimingRunner.extract',
                                extract):
                    with mock.patch(
                            'tlsfuzzer.timing_runner.TimingRunner.analyse'
                    ) as analyse:
                        with mock.patch('tlsfuzzer.timing_runner.Thread'):
                            with mock.patch(
                                    'tlsfuzzer.timing_runner.time.sleep'):
                                with mock.patch(
                                        'tlsfuzzer.timing_runner.Runner'
                                ) as runner:
                                    ret = self.runner.run()
                                    self.assertEqual(runner.call_count,
                                                     WARM_UP + 9)
                                    extract.assert_called_once()
                                    self.assertEqual(analyse.call_count, 0)
                                    self.assertEqual(ret, 2)

    def test_run_tcpdump_failure(self):
        self.runner.tests = {"A": None, "B": None, "C": None}
        with mock.patch(
                '__main__.__builtins__.open',
                self._mock_open(
                    read_data="A,B,C\r\n0,2,1\r\n2,0,1\r\n2,1,0\r\n")):
            with mock.patch('tlsfuzzer.timing_runner.TimingRunner.sniff'):
                with mock.patch(
                        'tlsfuzzer.timing_runner.TimingRunner.extract'):
                    with mock.patch(
                            'tlsfuzzer.timing_runner.TimingRunner.analyse'):
                        with mock.patch('tlsfuzzer.timing_runner.Thread'):
                            with mock.patch(
                                    'tlsfuzzer.timing_runner.time.sleep'):
                                with mock.patch(
                                        'tlsfuzzer.timing_runner.Runner'
                                ) as runner:
                                    self.runner.tcpdump_running = False
                                    self.assertRaises(SystemExit,
                                                      self.runner.run)
                                    self.assertEqual(runner.call_count, 0)

    @unittest.skipIf(is_33(), reason="Skipping because of a bug in unittest")
    def test_run_test_failure(self):
        self.runner.tests = {"A": None, "B": None, "C": None}
        self.runner.tcpdump_running = True

        def raise_error(*args, **kwargs):
            raise Exception()

        with mock.patch(
                '__main__.__builtins__.open',
                self._mock_open(
                    read_data="A,B,C\r\n0,2,1\r\n2,0,1\r\n2,1,0\r\n")):
            with mock.patch('tlsfuzzer.timing_runner.TimingRunner.sniff'):
                with mock.patch(
                        'tlsfuzzer.timing_runner.TimingRunner.analyse'):
                    with mock.patch(
                            'tlsfuzzer.timing_runner.TimingRunner.extract'):
                        with mock.patch('tlsfuzzer.timing_runner.Thread'):
                            with mock.patch(
                                    'tlsfuzzer.timing_runner.time.sleep'):
                                with mock.patch(
                                        'tlsfuzzer.timing_runner.Runner'
                                ) as runner:
                                    runner.return_value.run.side_effect = raise_error
                                    self.assertRaises(AssertionError,
                                                      self.runner.run)

    def test__format_seconds_with_seconds(self):
        self.assertEqual(TimingRunner._format_seconds(12.5), "12.50s")

    def test__format_seconds_with_minutes(self):
        self.assertEqual(TimingRunner._format_seconds(60 * 35), "35m 0.00s")

    def test__format_seconds_with_hours(self):
        self.assertEqual(TimingRunner._format_seconds(60 * 60), "1h 0m 0.00s")

    def test__format_seconds_with_days(self):
        self.assertEqual(TimingRunner._format_seconds(24 * 60 * 60 * 2),
                         "2d 0h 0m 0.00s")
Example #12
0
 def test_create_dir(self):
     with mock.patch('tlsfuzzer.timing_runner.os.mkdir') as mock_mkdir:
         TimingRunner("test", [], "/outdir", "localhost", 4433, "lo")
         mock_mkdir.assert_called_once()
def main():
    """Check if server is not vulnerable to Bleichenbacher attack"""
    host = "localhost"
    port = 4433
    num_limit = 50
    run_exclude = set()
    expected_failures = {}
    last_exp_tmp = None
    timeout = 1.0
    alert = AlertDescription.bad_record_mac
    level = AlertLevel.fatal
    srv_extensions = {ExtensionType.renegotiation_info: None}
    no_sni = False
    repetitions = 100
    interface = None
    timing = False
    outdir = "/tmp"
    cipher = CipherSuite.TLS_RSA_WITH_AES_128_CBC_SHA

    argv = sys.argv[1:]
    opts, args = getopt.getopt(argv, "h:p:e:x:X:t:n:a:l:l:o:i:C:",
                               ["help", "no-safe-renego", "no-sni", "repeat="])
    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 == '-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 == '-n':
            num_limit = int(arg)
        elif opt == '-C':
            if arg[:2] == '0x':
                cipher = int(arg, 16)
            else:
                try:
                    cipher = getattr(CipherSuite, arg)
                except AttributeError:
                    cipher = int(arg)
        elif opt == '-t':
            timeout = float(arg)
        elif opt == '-a':
            alert = int(arg)
        elif opt == '-l':
            level = int(arg)
        elif opt == "-i":
            timing = True
            interface = arg
        elif opt == '-o':
            outdir = arg
        elif opt == "--repeat":
            repetitions = int(arg)
        elif opt == "--no-safe-renego":
            srv_extensions = None
        elif opt == "--no-sni":
            no_sni = True
        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

    cln_extensions = {ExtensionType.renegotiation_info: None}
    if is_valid_hostname(host) and not no_sni:
        cln_extensions[ExtensionType.server_name] = \
            SNIExtension().create(bytearray(host, 'ascii'))

    # RSA key exchange check
    if cipher not in CipherSuite.certSuites:
        print("Ciphersuite has to use RSA key exchange.")
        exit(1)

    conversations = {}

    conversation = Connect(host, port)
    node = conversation
    ciphers = [cipher]
    node = node.add_child(
        ClientHelloGenerator(ciphers, extensions=cln_extensions))
    node = node.add_child(ExpectServerHello(extensions=srv_extensions))
    node = node.add_child(ExpectCertificate())
    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\r\n\r\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()
    node = node.add_child(ExpectClose())
    conversations["sanity"] = conversation

    runner = Runner(conversation)
    try:
        runner.run()
    except Exception as exp:
        # Exception means the server rejected the ciphersuite
        print("Failing on {0} because server does not support it. ".format(
            CipherSuite.ietfNames[cipher]))
        print(20 * '=')
        exit(1)

    # check if a certain number doesn't trip up the server
    # (essentially a second sanity test)
    conversation = Connect(host, port)
    node = conversation
    ciphers = [cipher]
    node = node.add_child(
        ClientHelloGenerator(ciphers, extensions=cln_extensions))
    node = node.add_child(ExpectServerHello(extensions=srv_extensions))

    node = node.add_child(ExpectCertificate())
    node = node.add_child(ExpectServerHelloDone())
    node = node.add_child(ClientKeyExchangeGenerator(padding_subs={2: 1}))
    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\r\n\r\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()
    node = node.add_child(ExpectClose())

    conversations[
        "sanity - static non-zero byte in random padding"] = conversation

    # set 2nd byte of padding to 3 (invalid value)
    conversation = Connect(host, port)
    node = conversation
    ciphers = [cipher]
    node = node.add_child(
        ClientHelloGenerator(ciphers, extensions=cln_extensions))
    node = node.add_child(ExpectServerHello(extensions=srv_extensions))

    node = node.add_child(ExpectCertificate())
    node = node.add_child(ExpectServerHelloDone())
    node = node.add_child(TCPBufferingEnable())
    node = node.add_child(ClientKeyExchangeGenerator(padding_subs={1: 3}))
    node = node.add_child(ChangeCipherSpecGenerator())
    node = node.add_child(FinishedGenerator())
    node = node.add_child(
        ApplicationDataGenerator(bytearray(b"GET / HTTP/1.0\r\n\r\n")))
    node = node.add_child(TCPBufferingDisable())
    node = node.add_child(TCPBufferingFlush())
    node = node.add_child(ExpectAlert(level, alert))
    node.add_child(ExpectClose())

    conversations["set PKCS#1 padding type to 3"] = conversation

    # set 2nd byte of padding to 1 (signing)
    conversation = Connect(host, port)
    node = conversation
    ciphers = [cipher]
    node = node.add_child(
        ClientHelloGenerator(ciphers, extensions=cln_extensions))
    node = node.add_child(ExpectServerHello(extensions=srv_extensions))

    node = node.add_child(ExpectCertificate())
    node = node.add_child(ExpectServerHelloDone())
    node = node.add_child(TCPBufferingEnable())
    node = node.add_child(ClientKeyExchangeGenerator(padding_subs={1: 1}))
    node = node.add_child(ChangeCipherSpecGenerator())
    node = node.add_child(FinishedGenerator())
    node = node.add_child(
        ApplicationDataGenerator(bytearray(b"GET / HTTP/1.0\r\n\r\n")))
    node = node.add_child(TCPBufferingDisable())
    node = node.add_child(TCPBufferingFlush())
    node = node.add_child(ExpectAlert(level, alert))
    node.add_child(ExpectClose())

    conversations["set PKCS#1 padding type to 1"] = conversation

    # test early zero in random data
    conversation = Connect(host, port)
    node = conversation
    ciphers = [cipher]
    node = node.add_child(
        ClientHelloGenerator(ciphers, extensions=cln_extensions))
    node = node.add_child(ExpectServerHello(extensions=srv_extensions))

    node = node.add_child(ExpectCertificate())
    node = node.add_child(ExpectServerHelloDone())
    node = node.add_child(TCPBufferingEnable())
    node = node.add_child(ClientKeyExchangeGenerator(padding_subs={4: 0}))
    node = node.add_child(ChangeCipherSpecGenerator())
    node = node.add_child(FinishedGenerator())
    node = node.add_child(
        ApplicationDataGenerator(bytearray(b"GET / HTTP/1.0\r\n\r\n")))
    node = node.add_child(TCPBufferingDisable())
    node = node.add_child(TCPBufferingFlush())
    node = node.add_child(ExpectAlert(level, alert))
    node.add_child(ExpectClose())

    conversations["zero byte in random padding"] = conversation

    # check if early padding separator is detected
    conversation = Connect(host, port)
    node = conversation
    ciphers = [cipher]
    node = node.add_child(
        ClientHelloGenerator(ciphers, extensions=cln_extensions))
    node = node.add_child(ExpectServerHello(extensions=srv_extensions))

    node = node.add_child(ExpectCertificate())
    node = node.add_child(ExpectServerHelloDone())
    node = node.add_child(TCPBufferingEnable())
    node = node.add_child(ClientKeyExchangeGenerator(padding_subs={-2: 0}))
    node = node.add_child(ChangeCipherSpecGenerator())
    node = node.add_child(FinishedGenerator())
    node = node.add_child(
        ApplicationDataGenerator(bytearray(b"GET / HTTP/1.0\r\n\r\n")))
    node = node.add_child(TCPBufferingDisable())
    node = node.add_child(TCPBufferingFlush())
    node = node.add_child(ExpectAlert(level, alert))
    node.add_child(ExpectClose())

    conversations["zero byte in last byte of random padding"] = conversation

    # check if separator without any random padding is detected
    conversation = Connect(host, port)
    node = conversation
    ciphers = [cipher]
    node = node.add_child(
        ClientHelloGenerator(ciphers, extensions=cln_extensions))
    node = node.add_child(ExpectServerHello(extensions=srv_extensions))

    node = node.add_child(ExpectCertificate())
    node = node.add_child(ExpectServerHelloDone())
    node = node.add_child(TCPBufferingEnable())
    node = node.add_child(ClientKeyExchangeGenerator(padding_subs={2: 0}))
    node = node.add_child(ChangeCipherSpecGenerator())
    node = node.add_child(FinishedGenerator())
    node = node.add_child(
        ApplicationDataGenerator(bytearray(b"GET / HTTP/1.0\r\n\r\n")))
    node = node.add_child(TCPBufferingDisable())
    node = node.add_child(TCPBufferingFlush())
    node = node.add_child(ExpectAlert(level, alert))
    node.add_child(ExpectClose())

    conversations["zero byte in first byte of random padding"] = conversation

    # check if invalid first byte of encoded value is correctly detecte
    conversation = Connect(host, port)
    node = conversation
    ciphers = [cipher]
    node = node.add_child(
        ClientHelloGenerator(ciphers, extensions=cln_extensions))
    node = node.add_child(ExpectServerHello(extensions=srv_extensions))

    node = node.add_child(ExpectCertificate())
    node = node.add_child(ExpectServerHelloDone())
    node = node.add_child(TCPBufferingEnable())
    node = node.add_child(ClientKeyExchangeGenerator(padding_subs={0: 1}))
    node = node.add_child(ChangeCipherSpecGenerator())
    node = node.add_child(FinishedGenerator())
    node = node.add_child(
        ApplicationDataGenerator(bytearray(b"GET / HTTP/1.0\r\n\r\n")))
    node = node.add_child(TCPBufferingDisable())
    node = node.add_child(TCPBufferingFlush())
    node = node.add_child(ExpectAlert(level, alert))
    node.add_child(ExpectClose())

    conversations["invalid version number in padding"] = conversation

    # check if no null separator in padding is detected
    conversation = Connect(host, port)
    node = conversation
    ciphers = [cipher]
    node = node.add_child(
        ClientHelloGenerator(ciphers, extensions=cln_extensions))
    node = node.add_child(ExpectServerHello(extensions=srv_extensions))

    node = node.add_child(ExpectCertificate())
    node = node.add_child(ExpectServerHelloDone())
    node = node.add_child(TCPBufferingEnable())
    node = node.add_child(ClientKeyExchangeGenerator(padding_subs={-1: 1}))
    node = node.add_child(ChangeCipherSpecGenerator())
    node = node.add_child(FinishedGenerator())
    node = node.add_child(
        ApplicationDataGenerator(bytearray(b"GET / HTTP/1.0\r\n\r\n")))
    node = node.add_child(TCPBufferingDisable())
    node = node.add_child(TCPBufferingFlush())
    node = node.add_child(ExpectAlert(level, alert))
    node.add_child(ExpectClose())

    conversations["no null separator in padding"] = conversation

    # check if no null separator in padding is detected
    # but with PMS set to non-zero
    conversation = Connect(host, port)
    node = conversation
    ciphers = [cipher]
    node = node.add_child(
        ClientHelloGenerator(ciphers, extensions=cln_extensions))
    node = node.add_child(ExpectServerHello(extensions=srv_extensions))

    node = node.add_child(ExpectCertificate())
    node = node.add_child(ExpectServerHelloDone())
    node = node.add_child(TCPBufferingEnable())
    node = node.add_child(
        ClientKeyExchangeGenerator(padding_subs={-1: 1},
                                   premaster_secret=bytearray([1] * 48)))
    node = node.add_child(ChangeCipherSpecGenerator())
    node = node.add_child(FinishedGenerator())
    node = node.add_child(
        ApplicationDataGenerator(bytearray(b"GET / HTTP/1.0\r\n\r\n")))
    node = node.add_child(TCPBufferingDisable())
    node = node.add_child(TCPBufferingFlush())
    node = node.add_child(ExpectAlert(level, alert))
    node.add_child(ExpectClose())

    conversations["no null separator in encrypted value"] = conversation

    # check if too short PMS is detected
    conversation = Connect(host, port)
    node = conversation
    ciphers = [cipher]
    node = node.add_child(
        ClientHelloGenerator(ciphers, extensions=cln_extensions))
    node = node.add_child(ExpectServerHello(extensions=srv_extensions))

    node = node.add_child(ExpectCertificate())
    node = node.add_child(ExpectServerHelloDone())
    node = node.add_child(TCPBufferingEnable())
    node = node.add_child(
        ClientKeyExchangeGenerator(premaster_secret=bytearray([1, 1])))
    node = node.add_child(ChangeCipherSpecGenerator())
    node = node.add_child(FinishedGenerator())
    node = node.add_child(
        ApplicationDataGenerator(bytearray(b"GET / HTTP/1.0\r\n\r\n")))
    node = node.add_child(TCPBufferingDisable())
    node = node.add_child(TCPBufferingFlush())
    node = node.add_child(ExpectAlert(level, alert))
    node.add_child(ExpectClose())

    conversations["two byte long PMS (TLS version only)"] = conversation

    # check if no encrypted payload is detected
    conversation = Connect(host, port)
    node = conversation
    ciphers = [cipher]
    node = node.add_child(
        ClientHelloGenerator(ciphers, extensions=cln_extensions))
    node = node.add_child(ExpectServerHello(extensions=srv_extensions))

    node = node.add_child(ExpectCertificate())
    node = node.add_child(ExpectServerHelloDone())
    node = node.add_child(TCPBufferingEnable())
    # the TLS version is always set, so we mask the real padding separator
    # and set the last byte of PMS to 0
    node = node.add_child(
        ClientKeyExchangeGenerator(padding_subs={-1: 1},
                                   premaster_secret=bytearray([1, 1, 0])))
    node = node.add_child(ChangeCipherSpecGenerator())
    node = node.add_child(FinishedGenerator())
    node = node.add_child(
        ApplicationDataGenerator(bytearray(b"GET / HTTP/1.0\r\n\r\n")))
    node = node.add_child(TCPBufferingDisable())
    node = node.add_child(TCPBufferingFlush())
    node = node.add_child(ExpectAlert(level, alert))
    node.add_child(ExpectClose())

    conversations["no encrypted value"] = conversation

    # check if too short encrypted payload is detected
    conversation = Connect(host, port)
    node = conversation
    ciphers = [cipher]
    node = node.add_child(
        ClientHelloGenerator(ciphers, extensions=cln_extensions))
    node = node.add_child(ExpectServerHello(extensions=srv_extensions))

    node = node.add_child(ExpectCertificate())
    node = node.add_child(ExpectServerHelloDone())
    node = node.add_child(TCPBufferingEnable())
    # the TLS version is always set, so we mask the real padding separator
    # and set the last byte of PMS to 0
    node = node.add_child(
        ClientKeyExchangeGenerator(padding_subs={-1: 1},
                                   premaster_secret=bytearray([1, 1, 0, 3])))
    node = node.add_child(ChangeCipherSpecGenerator())
    node = node.add_child(FinishedGenerator())
    node = node.add_child(
        ApplicationDataGenerator(bytearray(b"GET / HTTP/1.0\r\n\r\n")))
    node = node.add_child(TCPBufferingDisable())
    node = node.add_child(TCPBufferingFlush())
    node = node.add_child(ExpectAlert(level, alert))
    node.add_child(ExpectClose())

    conversations["one byte encrypted value"] = conversation

    # check if too short PMS is detected
    conversation = Connect(host, port)
    node = conversation
    ciphers = [cipher]
    node = node.add_child(
        ClientHelloGenerator(ciphers, extensions=cln_extensions))
    node = node.add_child(ExpectServerHello(extensions=srv_extensions))

    node = node.add_child(ExpectCertificate())
    node = node.add_child(ExpectServerHelloDone())
    node = node.add_child(TCPBufferingEnable())
    node = node.add_child(
        ClientKeyExchangeGenerator(premaster_secret=bytearray([1] * 47)))
    node = node.add_child(ChangeCipherSpecGenerator())
    node = node.add_child(FinishedGenerator())
    node = node.add_child(
        ApplicationDataGenerator(bytearray(b"GET / HTTP/1.0\r\n\r\n")))
    node = node.add_child(TCPBufferingDisable())
    node = node.add_child(TCPBufferingFlush())
    node = node.add_child(ExpectAlert(level, alert))
    node.add_child(ExpectClose())

    conversations["too short (47-byte) pre master secret"] = conversation

    # check if too short PMS is detected
    conversation = Connect(host, port)
    node = conversation
    ciphers = [cipher]
    node = node.add_child(
        ClientHelloGenerator(ciphers, extensions=cln_extensions))
    node = node.add_child(ExpectServerHello(extensions=srv_extensions))

    node = node.add_child(ExpectCertificate())
    node = node.add_child(ExpectServerHelloDone())
    node = node.add_child(TCPBufferingEnable())
    node = node.add_child(
        ClientKeyExchangeGenerator(premaster_secret=bytearray([1] * 4)))
    node = node.add_child(ChangeCipherSpecGenerator())
    node = node.add_child(FinishedGenerator())
    node = node.add_child(
        ApplicationDataGenerator(bytearray(b"GET / HTTP/1.0\r\n\r\n")))
    node = node.add_child(TCPBufferingDisable())
    node = node.add_child(TCPBufferingFlush())
    node = node.add_child(ExpectAlert(level, alert))
    node.add_child(ExpectClose())

    conversations["very short (4-byte) pre master secret"] = conversation

    # check if too long PMS is detected
    conversation = Connect(host, port)
    node = conversation
    ciphers = [cipher]
    node = node.add_child(
        ClientHelloGenerator(ciphers, extensions=cln_extensions))
    node = node.add_child(ExpectServerHello(extensions=srv_extensions))

    node = node.add_child(ExpectCertificate())
    node = node.add_child(ExpectServerHelloDone())
    node = node.add_child(TCPBufferingEnable())
    node = node.add_child(
        ClientKeyExchangeGenerator(premaster_secret=bytearray([1] * 49)))
    node = node.add_child(ChangeCipherSpecGenerator())
    node = node.add_child(FinishedGenerator())
    node = node.add_child(
        ApplicationDataGenerator(bytearray(b"GET / HTTP/1.0\r\n\r\n")))
    node = node.add_child(TCPBufferingDisable())
    node = node.add_child(TCPBufferingFlush())
    node = node.add_child(ExpectAlert(level, alert))
    node.add_child(ExpectClose())

    conversations["too long (49-byte) pre master secret"] = conversation

    # check if wrong TLS version number is rejected
    conversation = Connect(host, port)
    node = conversation
    ciphers = [cipher]
    node = node.add_child(
        ClientHelloGenerator(ciphers, extensions=cln_extensions))
    node = node.add_child(ExpectServerHello(extensions=srv_extensions))

    node = node.add_child(ExpectCertificate())
    node = node.add_child(ExpectServerHelloDone())
    node = node.add_child(TCPBufferingEnable())
    node = node.add_child(ClientKeyExchangeGenerator(client_version=(2, 2)))
    node = node.add_child(ChangeCipherSpecGenerator())
    node = node.add_child(FinishedGenerator())
    node = node.add_child(
        ApplicationDataGenerator(bytearray(b"GET / HTTP/1.0\r\n\r\n")))
    node = node.add_child(TCPBufferingDisable())
    node = node.add_child(TCPBufferingFlush())
    node = node.add_child(ExpectAlert(level, alert))
    node.add_child(ExpectClose())

    conversations[
        "wrong TLS version (2, 2) in pre master secret"] = conversation

    # check if wrong TLS version number is rejected
    conversation = Connect(host, port)
    node = conversation
    ciphers = [cipher]
    node = node.add_child(
        ClientHelloGenerator(ciphers, extensions=cln_extensions))
    node = node.add_child(ExpectServerHello(extensions=srv_extensions))

    node = node.add_child(ExpectCertificate())
    node = node.add_child(ExpectServerHelloDone())
    node = node.add_child(TCPBufferingEnable())
    node = node.add_child(ClientKeyExchangeGenerator(client_version=(0, 0)))
    node = node.add_child(ChangeCipherSpecGenerator())
    node = node.add_child(FinishedGenerator())
    node = node.add_child(
        ApplicationDataGenerator(bytearray(b"GET / HTTP/1.0\r\n\r\n")))
    node = node.add_child(TCPBufferingDisable())
    node = node.add_child(TCPBufferingFlush())
    node = node.add_child(ExpectAlert(level, alert))
    node.add_child(ExpectClose())

    conversations[
        "wrong TLS version (0, 0) in pre master secret"] = conversation

    # check if too short PKCS padding is detected
    conversation = Connect(host, port)
    node = conversation
    ciphers = [cipher]
    node = node.add_child(
        ClientHelloGenerator(ciphers, extensions=cln_extensions))
    node = node.add_child(ExpectServerHello(extensions=srv_extensions))

    node = node.add_child(ExpectCertificate())
    node = node.add_child(ExpectServerHelloDone())
    node = node.add_child(TCPBufferingEnable())
    # move the start of the padding forward, essentially encrypting two 0 bytes
    # at the beginning of the padding, but since those are transformed into a number
    # their existence is lost and it just like the padding was too small
    node = node.add_child(ClientKeyExchangeGenerator(padding_subs={
        1: 0,
        2: 2
    }))
    node = node.add_child(ChangeCipherSpecGenerator())
    node = node.add_child(FinishedGenerator())
    node = node.add_child(
        ApplicationDataGenerator(bytearray(b"GET / HTTP/1.0\r\n\r\n")))
    node = node.add_child(TCPBufferingDisable())
    node = node.add_child(TCPBufferingFlush())
    node = node.add_child(ExpectAlert(level, alert))
    node.add_child(ExpectClose())

    conversations["too short PKCS padding"] = conversation

    # check if too long PKCS padding is detected
    conversation = Connect(host, port)
    node = conversation
    ciphers = [cipher]
    node = node.add_child(
        ClientHelloGenerator(ciphers, extensions=cln_extensions))
    node = node.add_child(ExpectServerHello(extensions=srv_extensions))

    node = node.add_child(ExpectCertificate())
    node = node.add_child(ExpectServerHelloDone())
    node = node.add_child(TCPBufferingEnable())
    # move the start of the padding backward, essentially encrypting no 0 bytes
    # at the beginning of the padding, but since those are transformed into a number
    # its lack is lost and it just like the padding was too big
    node = node.add_child(ClientKeyExchangeGenerator(padding_subs={0: 2}))
    node = node.add_child(ChangeCipherSpecGenerator())
    node = node.add_child(FinishedGenerator())
    node = node.add_child(
        ApplicationDataGenerator(bytearray(b"GET / HTTP/1.0\r\n\r\n")))
    node = node.add_child(TCPBufferingDisable())
    node = node.add_child(TCPBufferingFlush())
    node = node.add_child(ExpectAlert(level, alert))
    node.add_child(ExpectClose())

    conversations["too long PKCS padding"] = conversation

    # fuzz MAC in the Finshed message to make decryption fail
    conversation = Connect(host, port)
    node = conversation
    ciphers = [cipher]
    node = node.add_child(
        ClientHelloGenerator(ciphers, extensions=cln_extensions))
    node = node.add_child(ExpectServerHello(extensions=srv_extensions))

    node = node.add_child(ExpectCertificate())
    node = node.add_child(ExpectServerHelloDone())
    node = node.add_child(TCPBufferingEnable())
    node = node.add_child(ClientKeyExchangeGenerator())
    node = node.add_child(ChangeCipherSpecGenerator())
    node = node.add_child(fuzz_mac(FinishedGenerator(), xors={0: 0xff}))
    node = node.add_child(
        ApplicationDataGenerator(bytearray(b"GET / HTTP/1.0\r\n\r\n")))
    node = node.add_child(TCPBufferingDisable())
    node = node.add_child(TCPBufferingFlush())
    node = node.add_child(ExpectAlert(level, alert))
    node.add_child(ExpectClose())

    conversations["invalid MAC in Finished on pos 0"] = conversation

    conversation = Connect(host, port)
    node = conversation
    ciphers = [cipher]
    node = node.add_child(
        ClientHelloGenerator(ciphers, extensions=cln_extensions))
    node = node.add_child(ExpectServerHello(extensions=srv_extensions))

    node = node.add_child(ExpectCertificate())
    node = node.add_child(ExpectServerHelloDone())
    node = node.add_child(TCPBufferingEnable())
    node = node.add_child(ClientKeyExchangeGenerator())
    node = node.add_child(ChangeCipherSpecGenerator())
    node = node.add_child(fuzz_mac(FinishedGenerator(), xors={-1: 0xff}))
    node = node.add_child(
        ApplicationDataGenerator(bytearray(b"GET / HTTP/1.0\r\n\r\n")))
    node = node.add_child(TCPBufferingDisable())
    node = node.add_child(TCPBufferingFlush())
    node = node.add_child(ExpectAlert(level, alert))
    node.add_child(ExpectClose())

    conversations["invalid MAC in Finished on pos -1"] = conversation

    # run the 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)

    print("Running tests for {0}".format(CipherSuite.ietfNames[cipher]))

    for c_name, c_test in ordered_tests:
        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 > 0:
        sys.exit(1)
    elif timing:
        # if regular tests passed, run timing collection and analysis
        if TimingRunner.check_tcpdump():
            timing_runner = TimingRunner(
                "{0}_{1}".format(sys.argv[0], CipherSuite.ietfNames[cipher]),
                sampled_tests, outdir, host, port, interface)
            print("Running timing tests...")
            timing_runner.generate_log(run_only, run_exclude, repetitions)
            ret_val = timing_runner.run()
            print("Statistical analysis exited with {0}".format(ret_val))
        else:
            print("Could not run timing tests because tcpdump is not present!")
            sys.exit(1)
        print(20 * '=')