# Author: Hubert Kario, (c) 2016
# Released under Gnu GPL v2.0, see LICENSE file for details
"""Test malformed signatures in Certificate Verify"""

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, \
        CertificateGenerator, CertificateVerifyGenerator, \
        AlertGenerator, TCPBufferingEnable, TCPBufferingDisable, \
        TCPBufferingFlush
from tlsfuzzer.expect import ExpectServerHello, ExpectCertificate, \
        ExpectServerHelloDone, ExpectChangeCipherSpec, ExpectFinished, \
        ExpectAlert, ExpectClose, ExpectCertificateRequest, \
        ExpectApplicationData, ExpectServerKeyExchange
from tlslite.extensions import SignatureAlgorithmsExtension, \
        SignatureAlgorithmsCertExtension, SupportedGroupsExtension
from tlslite.constants import CipherSuite, AlertDescription, \
        HashAlgorithm, SignatureAlgorithm, ExtensionType, GroupName
from tlslite.utils.keyfactory import parsePEMKey
from tlslite.x509 import X509
from tlslite.x509certchain import X509CertChain
from tlsfuzzer.utils.lists import natural_sort_keys
from tlsfuzzer.helpers import RSA_SIG_ALL


version = 6


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(" -d             negotiate (EC)DHE instead of RSA key exchange")
    print(" -k file.pem    file with private key for client")
    print(" -c file.pem    file with certificate for client")
    print(" --help         this message")


def main():
    """Check if malformed signatures in Certificate Verify are rejected"""
    host = "localhost"
    port = 4433
    num_limit = None
    run_exclude = set()
    expected_failures = {}
    last_exp_tmp = None
    private_key = None
    cert = None
    dhe = False

    argv = sys.argv[1:]
    opts, args = getopt.getopt(argv, "h:p:e:x:X:n:k:c:d", ["help"])
    for opt, arg in opts:
        if opt == '-h':
            host = arg
        elif opt == '-p':
            port = int(arg)
        elif opt == '-e':
            run_exclude.add(arg)
        elif opt == '-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 == '-k':
            text_key = open(arg, 'rb').read()
            if sys.version_info[0] >= 3:
                text_key = str(text_key, 'utf-8')
            private_key = parsePEMKey(text_key, private=True)
        elif opt == '-c':
            text_cert = open(arg, 'rb').read()
            if sys.version_info[0] >= 3:
                text_cert = str(text_cert, 'utf-8')
            cert = X509()
            cert.parse(text_cert)
        elif opt == "-d":
            dhe = True
        else:
            raise ValueError("Unknown option: {0}".format(opt))

    if not private_key:
        raise ValueError("Specify private key file using -k")
    if not cert:
        raise ValueError("Specify certificate file using -c")

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

    conversations = {}

    # sanity check for Client Certificates
    sanity_hash_alg = ("sha1", "sha256", "sha384")
    for hash_alg in sanity_hash_alg:
        conversation = Connect(host, port)
        node = conversation
        if dhe:
            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:
            ciphers = [CipherSuite.TLS_RSA_WITH_AES_128_CBC_SHA,
                       CipherSuite.TLS_EMPTY_RENEGOTIATION_INFO_SCSV]
        ext = {ExtensionType.signature_algorithms :
               SignatureAlgorithmsExtension().create([
                 (getattr(HashAlgorithm, x),
                  SignatureAlgorithm.rsa) for x in ['sha512', 'sha384', 'sha256',
                                                    'sha224', 'sha1', 'md5']]),
               ExtensionType.signature_algorithms_cert :
               SignatureAlgorithmsCertExtension().create(RSA_SIG_ALL)}
        if dhe:
            ext[ExtensionType.supported_groups] = SupportedGroupsExtension()\
                .create([GroupName.secp256r1, GroupName.ffdhe2048])
        node = node.add_child(ClientHelloGenerator(ciphers, extensions=ext))
        node = node.add_child(ExpectServerHello(version=(3, 3)))
        node = node.add_child(ExpectCertificate())
        if dhe:
            node = node.add_child(ExpectServerKeyExchange())
        node = node.add_child(ExpectCertificateRequest())
        node = node.add_child(ExpectServerHelloDone())
        node = node.add_child(TCPBufferingEnable())
        node = node.add_child(CertificateGenerator(X509CertChain([cert])))
        node = node.add_child(ClientKeyExchangeGenerator())
        sig_type = (getattr(HashAlgorithm, hash_alg), SignatureAlgorithm.rsa)
        node = node.add_child(CertificateVerifyGenerator(private_key,
                                                         msg_alg=sig_type
                                                         ))
        node = node.add_child(ChangeCipherSpecGenerator())
        node = node.add_child(FinishedGenerator())
        node = node.add_child(TCPBufferingDisable())
        node = node.add_child(TCPBufferingFlush())
        node = node.add_child(ExpectChangeCipherSpec())
        node = node.add_child(ExpectFinished())
        node = node.add_child(ApplicationDataGenerator(b"GET / HTTP/1.0\n\n"))
        node = node.add_child(ExpectApplicationData())
        node = node.add_child(AlertGenerator(AlertDescription.close_notify))
        node = node.add_child(ExpectClose())
        node.next_sibling = ExpectAlert()
        node.next_sibling.add_child(ExpectClose())

        conversations["sanity - {0}".format(hash_alg)] = conversation

    # try valid signatures but with wrong identifiers on TLS level
    for name, signature, envelope in [
            ("SHA-1 signature in SHA-256 envelope", HashAlgorithm.sha1,
             HashAlgorithm.sha256),
            ("SHA-256 signature in SHA-1 envelope", HashAlgorithm.sha256,
             HashAlgorithm.sha1),
            ("SHA-384 signature in SHA-256 envelope", HashAlgorithm.sha384,
             HashAlgorithm.sha256)]:
        conversation = Connect(host, port)
        node = conversation
        if dhe:
            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:
            ciphers = [CipherSuite.TLS_RSA_WITH_AES_128_CBC_SHA,
                       CipherSuite.TLS_EMPTY_RENEGOTIATION_INFO_SCSV]
        ext = {ExtensionType.signature_algorithms :
               SignatureAlgorithmsExtension().create([
                 (getattr(HashAlgorithm, x),
                  SignatureAlgorithm.rsa) for x in ['sha512', 'sha384', 'sha256',
                                                    'sha224', 'sha1', 'md5']]),
               ExtensionType.signature_algorithms_cert :
               SignatureAlgorithmsCertExtension().create(RSA_SIG_ALL)}
        if dhe:
            ext[ExtensionType.supported_groups] = SupportedGroupsExtension()\
                .create([GroupName.secp256r1, GroupName.ffdhe2048])
        node = node.add_child(ClientHelloGenerator(ciphers, extensions=ext))
        node = node.add_child(ExpectServerHello(version=(3, 3)))
        node = node.add_child(ExpectCertificate())
        if dhe:
            node = node.add_child(ExpectServerKeyExchange())
        node = node.add_child(ExpectCertificateRequest())
        node = node.add_child(ExpectServerHelloDone())
        node = node.add_child(TCPBufferingEnable())
        node = node.add_child(CertificateGenerator(X509CertChain([cert])))
        node = node.add_child(ClientKeyExchangeGenerator())
        sig_type = (signature, SignatureAlgorithm.rsa)
        msg_type = (envelope, SignatureAlgorithm.rsa)
        node = node.add_child(CertificateVerifyGenerator(private_key,
                                                         msg_alg=msg_type,
                                                         sig_alg=sig_type
                                                         ))
        node = node.add_child(ChangeCipherSpecGenerator())
        node = node.add_child(FinishedGenerator())
        node = node.add_child(TCPBufferingDisable())
        node = node.add_child(TCPBufferingFlush())
        # we expect closure or Alert and then closure of socket
        node = node.add_child(ExpectAlert(
            description=AlertDescription.decrypt_error))
        node.add_child(ExpectClose())

        conversations[name] = conversation

    # because the TLSv1.1 signatures are concatenation of MD5 and SHA1
    # implementation that just checks the hash, without verifying the Hash
    # Info structure in signature, will accept a TLSv1.1 signature
    # in a TLSv1.2 SHA-1 envelope
    conversation = Connect(host, port)
    node = conversation
    if dhe:
        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:
        ciphers = [CipherSuite.TLS_RSA_WITH_AES_128_CBC_SHA,
                   CipherSuite.TLS_EMPTY_RENEGOTIATION_INFO_SCSV]
    ext = {ExtensionType.signature_algorithms :
           SignatureAlgorithmsExtension().create([
             (getattr(HashAlgorithm, x),
              SignatureAlgorithm.rsa) for x in ['sha512', 'sha384', 'sha256',
                                                'sha224', 'sha1', 'md5']]),
           ExtensionType.signature_algorithms_cert :
           SignatureAlgorithmsCertExtension().create(RSA_SIG_ALL)}
    if dhe:
        ext[ExtensionType.supported_groups] = SupportedGroupsExtension()\
            .create([GroupName.secp256r1, GroupName.ffdhe2048])
    node = node.add_child(ClientHelloGenerator(ciphers, extensions=ext))
    node = node.add_child(ExpectServerHello(version=(3, 3)))
    node = node.add_child(ExpectCertificate())
    if dhe:
        node = node.add_child(ExpectServerKeyExchange())
    node = node.add_child(ExpectCertificateRequest())
    node = node.add_child(ExpectServerHelloDone())
    node = node.add_child(TCPBufferingEnable())
    node = node.add_child(CertificateGenerator(X509CertChain([cert])))
    node = node.add_child(ClientKeyExchangeGenerator())
    msg_alg = (HashAlgorithm.sha1, SignatureAlgorithm.rsa)
    node = node.add_child(CertificateVerifyGenerator(private_key,
                                                     msg_alg=msg_alg,
                                                     sig_version=(3, 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(
        description=AlertDescription.decrypt_error))
    node.add_child(ExpectClose())

    conversations["TLSv1.1 signature in SHA-1 TLSv1.2 envelope"] = 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 = [(k, v) for k, v in conversations.items() if
                    k.startswith('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)

    regular_tests = [(k, v) for k, v in conversations.items()
                     if not k.startswith('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
        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("CertificateVerify malformed signatures test\n")
    print("Note, that if one of the sanity tests fail, like the SHA-1")
    print("then the server most likely doesn't allow SHA-1 signatures in")
    print("CertificateVerify. If CertificateRequest doesn't list those")
    print("algorithms then CertificateVerify with SHA-1 should be rejected")
    print("using the illegal_parameter alert\n")

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

    if bad or xpass:
        sys.exit(1)

if __name__ == "__main__":
    main()