# Author: Hubert Kario, (c) 2018
# Released under Gnu GPL v2.0, see LICENSE file for details

"""Minimal test for verifying uniqueness of server ECDHE key shares."""

from __future__ import print_function
import traceback
import sys
import getopt
from itertools import chain
from random import sample

from tlsfuzzer.runner import Runner
from tlsfuzzer.messages import Connect, ClientHelloGenerator, \
        ClientKeyExchangeGenerator, ChangeCipherSpecGenerator, \
        FinishedGenerator, ApplicationDataGenerator, AlertGenerator, \
        CopyVariables
from tlsfuzzer.expect import ExpectServerHello, ExpectCertificate, \
        ExpectServerHelloDone, ExpectChangeCipherSpec, ExpectFinished, \
        ExpectAlert, ExpectClose, ExpectServerKeyExchange, \
        ExpectApplicationData

from tlslite.constants import CipherSuite, AlertLevel, AlertDescription, \
        ExtensionType, GroupName, ECPointFormat
from tlslite.extensions import ECPointFormatsExtension, \
        SupportedGroupsExtension
from tlsfuzzer.utils.lists import natural_sort_keys
from tlsfuzzer.helpers import uniqueness_check


version = 4


def help_msg():
    print("Usage: <script-name> [-h hostname] [-p port] [[probe-name] ...]")
    print(" -h hostname    name of the host to run the test against")
    print("                localhost by default")
    print(" -p port        port number to use for connection, 4433 by default")
    print(" probe-name     if present, will run only the probes with given")
    print("                names and not all of them, e.g \"sanity\"")
    print(" -e probe-name  exclude the probe from the list of the ones run")
    print("                may be specified multiple times")
    print(" -x probe-name  expect the probe to fail. When such probe passes despite being marked like this")
    print("                it will be reported in the test summary and the whole script will fail.")
    print("                May be specified multiple times.")
    print(" -X message     expect the `message` substring in exception raised during")
    print("                execution of preceding expected failure probe")
    print("                usage: [-x probe-name] [-X exception], order is compulsory!")
    print(" -n num         run 'num' or all(if 0) tests instead of default(all)")
    print("                (excluding \"sanity\" tests)")
    print(" --repeat num   repeat every test num times to collect the values")
    print("                32 by default")
    print(" -z             don't expect 1/n-1 record split in TLS1.0")
    print(" --help         this message")


def main():
    """Test if server provides unique ECDHE_RSA key shares."""
    host = "localhost"
    port = 4433
    num_limit = None
    run_exclude = set()
    expected_failures = {}
    last_exp_tmp = None
    repeats = 32
    record_split = True

    argv = sys.argv[1:]
    opts, args = getopt.getopt(argv, "h:p:e:x:X:n:z", ["help", "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 == '--help':
            help_msg()
            sys.exit(0)
        elif opt == '-z':
            record_split = False
        elif opt == '--repeat':
            repeats = int(arg)
        else:
            raise ValueError("Unknown option: {0}".format(opt))

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

    collected_randoms = []
    collected_key_shares = []
    collected_session_ids = []
    variables_check = \
        {'ServerHello.random':
         collected_randoms,
         'ServerKeyExchange.key_share':
         collected_key_shares,
         'ServerHello.session_id':
         collected_session_ids}

    groups = [GroupName.x25519, GroupName.x448, GroupName.secp256r1,
              GroupName.secp384r1, GroupName.secp521r1]

    conversations = {}

    conversation = Connect(host, port)
    node = conversation
    ciphers = [CipherSuite.TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA]
    groups_ext = SupportedGroupsExtension().create(groups)
    points_ext = ECPointFormatsExtension().create([ECPointFormat.uncompressed])
    exts = {ExtensionType.renegotiation_info: None,
            ExtensionType.supported_groups: groups_ext,
            ExtensionType.ec_point_formats: points_ext}
    node = node.add_child(ClientHelloGenerator(ciphers, extensions=exts))
    exts = {ExtensionType.renegotiation_info:None,
            ExtensionType.ec_point_formats: None}
    node = node.add_child(ExpectServerHello(extensions=exts))
    node = node.add_child(ExpectCertificate())
    node = node.add_child(ExpectServerKeyExchange())
    node = node.add_child(CopyVariables(variables_check))
    node = node.add_child(ExpectServerHelloDone())
    node = node.add_child(ClientKeyExchangeGenerator())
    node = node.add_child(ChangeCipherSpecGenerator())
    node = node.add_child(FinishedGenerator())
    node = node.add_child(ExpectChangeCipherSpec())
    node = node.add_child(ExpectFinished())
    node = node.add_child(ApplicationDataGenerator(
        bytearray(b"GET / HTTP/1.0\n\n")))
    node = node.add_child(ExpectApplicationData())
    node = node.add_child(AlertGenerator(AlertLevel.warning,
                                         AlertDescription.close_notify))
    node = node.add_child(ExpectAlert())
    node.next_sibling = ExpectClose()

    conversations["sanity"] = conversation

    for prot in [(3, 0), (3, 1), (3, 2), (3, 3)]:
        for ssl2 in [True, False]:
            for group in groups:
                # with SSLv2 compatible or with SSLv3 we can't advertise
                # curves so do just one check
                if (ssl2 or prot == (3, 0)) and group != groups[0]:
                    continue
                conversation = Connect(host, port,
                                       version=(0, 2) if ssl2 else (3, 0))
                node = conversation
                ciphers = [CipherSuite.TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA,
                           CipherSuite.TLS_EMPTY_RENEGOTIATION_INFO_SCSV]
                if ssl2 or prot == (3, 0):
                    exts = None
                else:
                    groups_ext = SupportedGroupsExtension().create([group])
                    exts = {ExtensionType.supported_groups: groups_ext,
                            ExtensionType.ec_point_formats: points_ext}
                node = node.add_child(ClientHelloGenerator(ciphers,
                                                           version=prot,
                                                           extensions=exts,
                                                           ssl2=ssl2))
                if prot > (3, 0):
                    if ssl2:
                        ext = {ExtensionType.renegotiation_info: None}
                    else:
                        ext = {ExtensionType.renegotiation_info: None,
                               ExtensionType.ec_point_formats: None}
                else:
                    ext = None
                node = node.add_child(ExpectServerHello(extensions=ext,
                                                        version=prot))
                node = node.add_child(ExpectCertificate())
                node = node.add_child(ExpectServerKeyExchange())
                node = node.add_child(CopyVariables(variables_check))
                node = node.add_child(ExpectServerHelloDone())
                node = node.add_child(ClientKeyExchangeGenerator())
                node = node.add_child(ChangeCipherSpecGenerator())
                node = node.add_child(FinishedGenerator())
                node = node.add_child(ExpectChangeCipherSpec())
                node = node.add_child(ExpectFinished())
                node = node.add_child(ApplicationDataGenerator(
                    bytearray(b"GET / HTTP/1.0\n\n")))
                node = node.add_child(ExpectApplicationData())
                if prot < (3, 2) and record_split:
                    # 1/n-1 record splitting
                    node = node.add_child(ExpectApplicationData())
                node = node.add_child(AlertGenerator(AlertLevel.warning,
                                                     AlertDescription.close_notify))
                node = node.add_child(ExpectAlert())
                node.next_sibling = ExpectClose()

                conversations["Protocol {0}{1}{2}".format(
                    prot,
                    "" if ssl2 or prot < (3, 1)
                        else " with {0} group".format(GroupName.toStr(group)),
                    " in SSLv2 compatible ClientHello" if ssl2 else "")] = \
                        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)

    for c_name, c_test in ordered_tests:
        if run_only and c_name not in run_only or c_name in run_exclude:
            continue
        for i in range(repeats):
            print("\"{1}\" repeat {0}...".format(i, 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)

    failed_tests = uniqueness_check(variables_check, good + bad)
    if failed_tests:
        print("\n".join(failed_tests))
    else:
        print("\n".join("{0} values: OK".format(i) for i in variables_check))

    print('')

    print("Check if the server provided random values are unique")
    print("Checks random and session_id from Server Hello and ECDHE key share")
    print("Note: not supporting ECDHE in SSLv3 or with SSLv2 Client Hello is")
    print("valid behaviour, as the client can't advertise groups it supports")
    print("there.")

    print("Test end")
    print(20 * '=')
    print("version: {0}".format(version))
    print(20 * '=')
    print("TOTAL: {0}".format(len(sampled_tests) + 2*len(sanity_tests)))
    print("SKIP: {0}".format(len(run_exclude.intersection(conversations.keys()))))
    print("PASS: {0}".format(good))
    print("XFAIL: {0}".format(xfail))
    print("FAIL: {0}".format(bad))
    print("XPASS: {0}".format(xpass))
    print(20 * '=')
    sort = sorted(xpassed ,key=natural_sort_keys)
    if len(sort):
        print("XPASSED:\n\t{0}".format('\n\t'.join(repr(i) for i in sort)))
    sort = sorted(failed, key=natural_sort_keys)
    if len(sort):
        print("FAILED:\n\t{0}".format('\n\t'.join(repr(i) for i in sort)))

    if bad or xpass or failed_tests:
        sys.exit(1)

if __name__ == "__main__":
    main()