# Author: Simo Sorce, (c) 2015-2018
# Released under Gnu GPL v2.0, see LICENSE file for details

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
from tlsfuzzer.expect import ExpectServerHello, ExpectCertificate, \
        ExpectServerHelloDone, ExpectChangeCipherSpec, ExpectFinished, \
        ExpectAlert, ExpectApplicationData, ExpectClose, \
        ExpectEncryptedExtensions, ExpectCertificateVerify, \
        ExpectNewSessionTicket, ExpectServerKeyExchange

from tlslite.constants import CipherSuite, AlertLevel, AlertDescription, \
        TLS_1_3_DRAFT, GroupName, ExtensionType, SignatureScheme
from tlslite.extensions import KeyShareEntry, ClientKeyShareExtension, \
        SupportedVersionsExtension, SupportedGroupsExtension, \
        SignatureAlgorithmsExtension, SignatureAlgorithmsCertExtension
from tlsfuzzer.utils.lists import natural_sort_keys
from tlsfuzzer.helpers import key_share_gen, RSA_SIG_ALL, \
        protocol_name_to_tuple


version = 1


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(" -n num         only run `num` random tests instead of a full set")
    print("                (excluding \"sanity\" tests)")
    print(" --server-max-protocol   TLS max protocol version the server is")
    print("                         set to use ('TLSv1.3', 'TLSv1.2', ...)")
    print(" -d             negotiate (EC)DHE instead of RSA key exchange")
    print(" --help         this message")


def main():
    host = "localhost"
    port = 4433
    num_limit = None
    run_exclude = set()
    srv_max_prot=None
    dhe = False

    argv = sys.argv[1:]
    opts, args = getopt.getopt(argv, "h:p:e:n:d", ["help",
                                                  "server-max-protocol="])
    for opt, arg in opts:
        if opt == '-h':
            host = arg
        elif opt == '-p':
            port = int(arg)
        elif opt == '-e':
            run_exclude.add(arg)
        elif opt == '-n':
            num_limit = int(arg)
        elif opt == '-d':
            dhe = True
        elif opt == '--help':
            help_msg()
            sys.exit(0)
        elif opt == '--server-max-protocol':
            srv_max_prot = protocol_name_to_tuple(arg)
        else:
            raise ValueError("Unknown option: {0}".format(opt))

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

    conversations = {}

    # normal connection
    conversation = Connect(host, port)
    node = conversation
    if srv_max_prot == None or srv_max_prot == (3, 4):
        ciphers = [CipherSuite.TLS_AES_128_GCM_SHA256,
                   CipherSuite.TLS_EMPTY_RENEGOTIATION_INFO_SCSV]
        ext = {}
        groups = [GroupName.secp256r1]
        key_shares = []
        for group in groups:
            key_shares.append(key_share_gen(group))
        ext[ExtensionType.key_share] = \
            ClientKeyShareExtension().create(key_shares)
        ext[ExtensionType.supported_versions] = \
            SupportedVersionsExtension().create([TLS_1_3_DRAFT, (3, 3)])
        ext[ExtensionType.supported_groups] = \
            SupportedGroupsExtension().create(groups)
        sig_algs = [SignatureScheme.rsa_pss_rsae_sha256,
                    SignatureScheme.rsa_pss_pss_sha256]
        ext[ExtensionType.signature_algorithms] = \
            SignatureAlgorithmsExtension().create(sig_algs)
        ext[ExtensionType.signature_algorithms_cert] = \
            SignatureAlgorithmsCertExtension().create(RSA_SIG_ALL)
        node = node.add_child(ClientHelloGenerator(ciphers, extensions=ext))
        node = node.add_child(ExpectServerHello())
        node = node.add_child(ExpectChangeCipherSpec())
        node = node.add_child(ExpectEncryptedExtensions())
        node = node.add_child(ExpectCertificate())
        node = node.add_child(ExpectCertificateVerify())
        node = node.add_child(ExpectFinished())
        node = node.add_child(FinishedGenerator())
        node = node.add_child(ApplicationDataGenerator(
        bytearray(b"GET / HTTP/1.0\r\n\r\n")))
        # This message is optional and may show up 0 to many times
        cycle = ExpectNewSessionTicket()
        node = node.add_child(cycle)
        node.add_child(cycle)

        node.next_sibling = ExpectApplicationData()
        node = node.next_sibling.add_child(AlertGenerator(AlertLevel.warning,
                                           AlertDescription.close_notify))

        node = node.add_child(ExpectAlert())
        node.next_sibling = ExpectClose()
    else:
        if dhe:
            ext = {}
            groups = [GroupName.secp256r1,
                      GroupName.ffdhe2048]
            ext[ExtensionType.supported_groups] = SupportedGroupsExtension()\
                .create(groups)
            ext[ExtensionType.signature_algorithms] = \
                SignatureAlgorithmsExtension().create(RSA_SIG_ALL)
            ciphers = [CipherSuite.TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA,
                       CipherSuite.TLS_DHE_RSA_WITH_AES_128_CBC_SHA,
                       CipherSuite.TLS_EMPTY_RENEGOTIATION_INFO_SCSV]
        else:
            ext = None
            ciphers = [CipherSuite.TLS_RSA_WITH_AES_128_CBC_SHA,
                       CipherSuite.TLS_EMPTY_RENEGOTIATION_INFO_SCSV]
        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(
            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()

    conversations["sanity"] = conversation

    # TLS 1.3 downgrade check
    for prot in [(3, 1), (3, 2), (3, 3)]:
        if srv_max_prot is not None and prot > srv_max_prot:
            continue
        conversation = Connect(host, port)
        node = conversation
        if dhe:
            ext = {}
            groups = [GroupName.secp256r1,
                      GroupName.ffdhe2048]
            ext[ExtensionType.supported_groups] = SupportedGroupsExtension()\
                .create(groups)
            ext[ExtensionType.signature_algorithms] = \
                SignatureAlgorithmsExtension().create(RSA_SIG_ALL)
            ciphers = [CipherSuite.TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA,
                       CipherSuite.TLS_DHE_RSA_WITH_AES_128_CBC_SHA,
                       CipherSuite.TLS_EMPTY_RENEGOTIATION_INFO_SCSV]
        else:
            ext = None
            ciphers = [CipherSuite.TLS_RSA_WITH_AES_128_CBC_SHA,
                       CipherSuite.TLS_EMPTY_RENEGOTIATION_INFO_SCSV]
        node = node.add_child(ClientHelloGenerator(ciphers, extensions=ext, version=prot))
        node = node.add_child(ExpectServerHello(
            server_max_protocol=srv_max_prot))
        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(
            bytearray(b"GET / HTTP/1.0\r\n\r\n")))
        node = node.add_child(ExpectApplicationData())
        if prot < (3, 2):
            # 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["TLS 1.3 downgrade check for Protocol {0}".format(
            prot)] = conversation

    # run the conversation
    good = 0
    bad = 0
    failed = []
    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'])]
    regular_tests = [(k, v) for k, v in conversations.items() if k != 'sanity']
    sampled_tests = sample(regular_tests, min(num_limit, len(regular_tests)))
    ordered_tests = chain(sanity_tests, sampled_tests, sanity_tests)

    for c_name, c_test in ordered_tests:
        if run_only and c_name not in run_only or c_name in run_exclude:
            continue
        print("{0} ...".format(c_name))

        runner = Runner(c_test)

        res = True
        try:
            runner.run()
        except Exception:
            print("Error while processing")
            print(traceback.format_exc())
            res = False

        if res:
            good += 1
            print("OK\n")
        else:
            bad += 1
            failed.append(c_name)

    print("Check if server correctly return ServerHello Random ")
    print("with downgrade protection values to TLS1.2 and below ")
    print("clients\n")
    print("version: {0}\n".format(version))

    print("Test end")
    print("successful: {0}".format(good))
    print("failed: {0}".format(bad))
    failed_sorted = sorted(failed, key=natural_sort_keys)
    print("  {0}".format('\n  '.join(repr(i) for i in failed_sorted)))

    if bad > 0:
        sys.exit(1)

if __name__ == "__main__":
    main()
