#!/usr/bin/env python
# -*- coding: utf-8 -*-

"""Tests for requests_kerberos."""

import base64
from mock import Mock, patch
from requests.compat import urlparse
import requests
import warnings


try:
    import kerberos
    kerberos_module_name='kerberos'
except ImportError:
    import winkerberos as kerberos  # On Windows
    kerberos_module_name = 'winkerberos'

import requests_kerberos
import unittest
from requests_kerberos.kerberos_ import _get_certificate_hash

# kerberos.authClientInit() is called with the service name (HTTP@FQDN) and
# returns 1 and a kerberos context object on success. Returns -1 on failure.
clientInit_complete = Mock(return_value=(1, "CTX"))
clientInit_error = Mock(return_value=(-1, "CTX"))

# kerberos.authGSSClientStep() is called with the kerberos context object
# returned by authGSSClientInit and the negotiate auth token provided in the
# http response's www-authenticate header. It returns 0 or 1 on success. 0
# Indicates that authentication is progressing but not complete.
clientStep_complete = Mock(return_value=1)
clientStep_continue = Mock(return_value=0)
clientStep_error = Mock(return_value=-1)
clientStep_exception = Mock(side_effect=kerberos.GSSError)

# kerberos.authGSSCLientResponse() is called with the kerberos context which
# was initially returned by authGSSClientInit and had been mutated by a call by
# authGSSClientStep. It returns a string.
clientResponse = Mock(return_value="GSSRESPONSE")

# Note: we're not using the @mock.patch decorator:
# > My only word of warning is that in the past, the patch decorator hides
# > tests when using the standard unittest library.
# > -- sigmavirus24 in https://github.com/requests/requests-kerberos/issues/1


class KerberosTestCase(unittest.TestCase):

    def setUp(self):
        """Setup."""
        clientInit_complete.reset_mock()
        clientInit_error.reset_mock()
        clientStep_complete.reset_mock()
        clientStep_continue.reset_mock()
        clientStep_error.reset_mock()
        clientStep_exception.reset_mock()
        clientResponse.reset_mock()

    def tearDown(self):
        """Teardown."""
        pass

    def test_negotate_value_extraction(self):
        response = requests.Response()
        response.headers = {'www-authenticate': 'negotiate token'}
        self.assertEqual(
            requests_kerberos.kerberos_._negotiate_value(response),
            'token'
        )

    def test_negotate_value_extraction_none(self):
        response = requests.Response()
        response.headers = {}
        self.assertTrue(
            requests_kerberos.kerberos_._negotiate_value(response) is None
        )

    def test_force_preemptive(self):
        with patch.multiple(kerberos_module_name,
                            authGSSClientInit=clientInit_complete,
                            authGSSClientResponse=clientResponse,
                            authGSSClientStep=clientStep_continue):
            auth = requests_kerberos.HTTPKerberosAuth(force_preemptive=True)

            request = requests.Request(url="http://www.example.org")

            auth.__call__(request)

            self.assertTrue('Authorization' in request.headers)
            self.assertEqual(request.headers.get('Authorization'), 'Negotiate GSSRESPONSE')

    def test_no_force_preemptive(self):
        with patch.multiple(kerberos_module_name,
                            authGSSClientInit=clientInit_complete,
                            authGSSClientResponse=clientResponse,
                            authGSSClientStep=clientStep_continue):
            auth = requests_kerberos.HTTPKerberosAuth()

            request = requests.Request(url="http://www.example.org")

            auth.__call__(request)

            self.assertTrue('Authorization' not in request.headers)

    def test_generate_request_header(self):
        with patch.multiple(kerberos_module_name,
                            authGSSClientInit=clientInit_complete,
                            authGSSClientResponse=clientResponse,
                            authGSSClientStep=clientStep_continue):
            response = requests.Response()
            response.url = "http://www.example.org/"
            response.headers = {'www-authenticate': 'negotiate token'}
            host = urlparse(response.url).hostname
            auth = requests_kerberos.HTTPKerberosAuth()
            self.assertEqual(
                auth.generate_request_header(response, host),
                "Negotiate GSSRESPONSE"
            )
            clientInit_complete.assert_called_with(
                "HTTP@www.example.org",
                gssflags=(
                    kerberos.GSS_C_MUTUAL_FLAG |
                    kerberos.GSS_C_SEQUENCE_FLAG),
                principal=None)
            clientStep_continue.assert_called_with("CTX", "token")
            clientResponse.assert_called_with("CTX")

    def test_generate_request_header_init_error(self):
        with patch.multiple(kerberos_module_name,
                            authGSSClientInit=clientInit_error,
                            authGSSClientResponse=clientResponse,
                            authGSSClientStep=clientStep_continue):
            response = requests.Response()
            response.url = "http://www.example.org/"
            response.headers = {'www-authenticate': 'negotiate token'}
            host = urlparse(response.url).hostname
            auth = requests_kerberos.HTTPKerberosAuth()
            self.assertRaises(requests_kerberos.exceptions.KerberosExchangeError,
                auth.generate_request_header, response, host
            )
            clientInit_error.assert_called_with(
                "HTTP@www.example.org",
                gssflags=(
                    kerberos.GSS_C_MUTUAL_FLAG |
                    kerberos.GSS_C_SEQUENCE_FLAG),
                principal=None)
            self.assertFalse(clientStep_continue.called)
            self.assertFalse(clientResponse.called)

    def test_generate_request_header_step_error(self):
        with patch.multiple(kerberos_module_name,
                            authGSSClientInit=clientInit_complete,
                            authGSSClientResponse=clientResponse,
                            authGSSClientStep=clientStep_error):
            response = requests.Response()
            response.url = "http://www.example.org/"
            response.headers = {'www-authenticate': 'negotiate token'}
            host = urlparse(response.url).hostname
            auth = requests_kerberos.HTTPKerberosAuth()
            self.assertRaises(requests_kerberos.exceptions.KerberosExchangeError,
                auth.generate_request_header, response, host
            )
            clientInit_complete.assert_called_with(
                "HTTP@www.example.org",
                gssflags=(
                    kerberos.GSS_C_MUTUAL_FLAG |
                    kerberos.GSS_C_SEQUENCE_FLAG),
                principal=None)
            clientStep_error.assert_called_with("CTX", "token")
            self.assertFalse(clientResponse.called)

    def test_authenticate_user(self):
        with patch.multiple(kerberos_module_name,
                            authGSSClientInit=clientInit_complete,
                            authGSSClientResponse=clientResponse,
                            authGSSClientStep=clientStep_continue):

            response_ok = requests.Response()
            response_ok.url = "http://www.example.org/"
            response_ok.status_code = 200
            response_ok.headers = {'www-authenticate': 'negotiate servertoken'}

            connection = Mock()
            connection.send = Mock(return_value=response_ok)

            raw = Mock()
            raw.release_conn = Mock(return_value=None)

            request = requests.Request()
            response = requests.Response()
            response.request = request
            response.url = "http://www.example.org/"
            response.headers = {'www-authenticate': 'negotiate token'}
            response.status_code = 401
            response.connection = connection
            response._content = ""
            response.raw = raw
            auth = requests_kerberos.HTTPKerberosAuth()
            r = auth.authenticate_user(response)

            self.assertTrue(response in r.history)
            self.assertEqual(r, response_ok)
            self.assertEqual(
                request.headers['Authorization'],
                'Negotiate GSSRESPONSE')
            connection.send.assert_called_with(request)
            raw.release_conn.assert_called_with()
            clientInit_complete.assert_called_with(
                "HTTP@www.example.org",
                gssflags=(
                    kerberos.GSS_C_MUTUAL_FLAG |
                    kerberos.GSS_C_SEQUENCE_FLAG),
                principal=None)
            clientStep_continue.assert_called_with("CTX", "token")
            clientResponse.assert_called_with("CTX")

    def test_handle_401(self):
        with patch.multiple(kerberos_module_name,
                            authGSSClientInit=clientInit_complete,
                            authGSSClientResponse=clientResponse,
                            authGSSClientStep=clientStep_continue):

            response_ok = requests.Response()
            response_ok.url = "http://www.example.org/"
            response_ok.status_code = 200
            response_ok.headers = {'www-authenticate': 'negotiate servertoken'}

            connection = Mock()
            connection.send = Mock(return_value=response_ok)

            raw = Mock()
            raw.release_conn = Mock(return_value=None)

            request = requests.Request()
            response = requests.Response()
            response.request = request
            response.url = "http://www.example.org/"
            response.headers = {'www-authenticate': 'negotiate token'}
            response.status_code = 401
            response.connection = connection
            response._content = ""
            response.raw = raw
            auth = requests_kerberos.HTTPKerberosAuth()
            r = auth.handle_401(response)

            self.assertTrue(response in r.history)
            self.assertEqual(r, response_ok)
            self.assertEqual(
                request.headers['Authorization'],
                'Negotiate GSSRESPONSE')
            connection.send.assert_called_with(request)
            raw.release_conn.assert_called_with()
            clientInit_complete.assert_called_with(
                "HTTP@www.example.org",
                gssflags=(
                    kerberos.GSS_C_MUTUAL_FLAG |
                    kerberos.GSS_C_SEQUENCE_FLAG),
                principal=None)
            clientStep_continue.assert_called_with("CTX", "token")
            clientResponse.assert_called_with("CTX")

    def test_authenticate_server(self):
        with patch.multiple(kerberos_module_name, authGSSClientStep=clientStep_complete):

            response_ok = requests.Response()
            response_ok.url = "http://www.example.org/"
            response_ok.status_code = 200
            response_ok.headers = {
                'www-authenticate': 'negotiate servertoken',
                'authorization': 'Negotiate GSSRESPONSE'}

            auth = requests_kerberos.HTTPKerberosAuth()
            auth.context = {"www.example.org": "CTX"}
            result = auth.authenticate_server(response_ok)

            self.assertTrue(result)
            clientStep_complete.assert_called_with("CTX", "servertoken")

    def test_handle_other(self):
        with patch(kerberos_module_name+'.authGSSClientStep', clientStep_complete):

            response_ok = requests.Response()
            response_ok.url = "http://www.example.org/"
            response_ok.status_code = 200
            response_ok.headers = {
                'www-authenticate': 'negotiate servertoken',
                'authorization': 'Negotiate GSSRESPONSE'}

            auth = requests_kerberos.HTTPKerberosAuth()
            auth.context = {"www.example.org": "CTX"}

            r = auth.handle_other(response_ok)

            self.assertEqual(r, response_ok)
            clientStep_complete.assert_called_with("CTX", "servertoken")

    def test_handle_response_200(self):
        with patch(kerberos_module_name+'.authGSSClientStep', clientStep_complete):

            response_ok = requests.Response()
            response_ok.url = "http://www.example.org/"
            response_ok.status_code = 200
            response_ok.headers = {
                'www-authenticate': 'negotiate servertoken',
                'authorization': 'Negotiate GSSRESPONSE'}

            auth = requests_kerberos.HTTPKerberosAuth()
            auth.context = {"www.example.org": "CTX"}

            r = auth.handle_response(response_ok)

            self.assertEqual(r, response_ok)
            clientStep_complete.assert_called_with("CTX", "servertoken")

    def test_handle_response_200_mutual_auth_required_failure(self):
        with patch(kerberos_module_name+'.authGSSClientStep', clientStep_error):

            response_ok = requests.Response()
            response_ok.url = "http://www.example.org/"
            response_ok.status_code = 200
            response_ok.headers = {}

            auth = requests_kerberos.HTTPKerberosAuth()
            auth.context = {"www.example.org": "CTX"}

            self.assertRaises(requests_kerberos.MutualAuthenticationError,
                              auth.handle_response,
                              response_ok)

            self.assertFalse(clientStep_error.called)

    def test_handle_response_200_mutual_auth_required_failure_2(self):
        with patch(kerberos_module_name+'.authGSSClientStep', clientStep_exception):

            response_ok = requests.Response()
            response_ok.url = "http://www.example.org/"
            response_ok.status_code = 200
            response_ok.headers = {
                'www-authenticate': 'negotiate servertoken',
                'authorization': 'Negotiate GSSRESPONSE'}

            auth = requests_kerberos.HTTPKerberosAuth()
            auth.context = {"www.example.org": "CTX"}

            self.assertRaises(requests_kerberos.MutualAuthenticationError,
                              auth.handle_response,
                              response_ok)

            clientStep_exception.assert_called_with("CTX", "servertoken")

    def test_handle_response_200_mutual_auth_optional_hard_failure(self):
        with patch(kerberos_module_name+'.authGSSClientStep', clientStep_error):

            response_ok = requests.Response()
            response_ok.url = "http://www.example.org/"
            response_ok.status_code = 200
            response_ok.headers = {
                'www-authenticate': 'negotiate servertoken',
                'authorization': 'Negotiate GSSRESPONSE'}

            auth = requests_kerberos.HTTPKerberosAuth(
                requests_kerberos.OPTIONAL)
            auth.context = {"www.example.org": "CTX"}

            self.assertRaises(requests_kerberos.MutualAuthenticationError,
                              auth.handle_response,
                              response_ok)

            clientStep_error.assert_called_with("CTX", "servertoken")

    def test_handle_response_200_mutual_auth_optional_soft_failure(self):
        with patch(kerberos_module_name+'.authGSSClientStep', clientStep_error):

            response_ok = requests.Response()
            response_ok.url = "http://www.example.org/"
            response_ok.status_code = 200

            auth = requests_kerberos.HTTPKerberosAuth(
                requests_kerberos.OPTIONAL)
            auth.context = {"www.example.org": "CTX"}

            r = auth.handle_response(response_ok)

            self.assertEqual(r, response_ok)

            self.assertFalse(clientStep_error.called)

    def test_handle_response_500_mutual_auth_required_failure(self):
        with patch(kerberos_module_name+'.authGSSClientStep', clientStep_error):

            response_500 = requests.Response()
            response_500.url = "http://www.example.org/"
            response_500.status_code = 500
            response_500.headers = {}
            response_500.request = "REQUEST"
            response_500.connection = "CONNECTION"
            response_500._content = "CONTENT"
            response_500.encoding = "ENCODING"
            response_500.raw = "RAW"
            response_500.cookies = "COOKIES"

            auth = requests_kerberos.HTTPKerberosAuth()
            auth.context = {"www.example.org": "CTX"}

            r = auth.handle_response(response_500)

            self.assertTrue(isinstance(r, requests_kerberos.kerberos_.SanitizedResponse))
            self.assertNotEqual(r, response_500)
            self.assertNotEqual(r.headers, response_500.headers)
            self.assertEqual(r.status_code, response_500.status_code)
            self.assertEqual(r.encoding, response_500.encoding)
            self.assertEqual(r.raw, response_500.raw)
            self.assertEqual(r.url, response_500.url)
            self.assertEqual(r.reason, response_500.reason)
            self.assertEqual(r.connection, response_500.connection)
            self.assertEqual(r.content, '')
            self.assertNotEqual(r.cookies, response_500.cookies)

            self.assertFalse(clientStep_error.called)

            # re-test with error response sanitizing disabled
            auth = requests_kerberos.HTTPKerberosAuth(sanitize_mutual_error_response=False)
            auth.context = {"www.example.org": "CTX"}

            r = auth.handle_response(response_500)

            self.assertFalse(isinstance(r, requests_kerberos.kerberos_.SanitizedResponse))

    def test_handle_response_500_mutual_auth_optional_failure(self):
        with patch(kerberos_module_name+'.authGSSClientStep', clientStep_error):

            response_500 = requests.Response()
            response_500.url = "http://www.example.org/"
            response_500.status_code = 500
            response_500.headers = {}
            response_500.request = "REQUEST"
            response_500.connection = "CONNECTION"
            response_500._content = "CONTENT"
            response_500.encoding = "ENCODING"
            response_500.raw = "RAW"
            response_500.cookies = "COOKIES"

            auth = requests_kerberos.HTTPKerberosAuth(
                requests_kerberos.OPTIONAL)
            auth.context = {"www.example.org": "CTX"}

            r = auth.handle_response(response_500)

            self.assertEqual(r, response_500)

            self.assertFalse(clientStep_error.called)

    def test_handle_response_401(self):
        # Get a 401 from server, authenticate, and get a 200 back.
        with patch.multiple(kerberos_module_name,
                            authGSSClientInit=clientInit_complete,
                            authGSSClientResponse=clientResponse,
                            authGSSClientStep=clientStep_continue):

            response_ok = requests.Response()
            response_ok.url = "http://www.example.org/"
            response_ok.status_code = 200
            response_ok.headers = {'www-authenticate': 'negotiate servertoken'}

            connection = Mock()
            connection.send = Mock(return_value=response_ok)

            raw = Mock()
            raw.release_conn = Mock(return_value=None)

            request = requests.Request()
            response = requests.Response()
            response.request = request
            response.url = "http://www.example.org/"
            response.headers = {'www-authenticate': 'negotiate token'}
            response.status_code = 401
            response.connection = connection
            response._content = ""
            response.raw = raw

            auth = requests_kerberos.HTTPKerberosAuth()
            auth.handle_other = Mock(return_value=response_ok)

            r = auth.handle_response(response)

            self.assertTrue(response in r.history)
            auth.handle_other.assert_called_once_with(response_ok)
            self.assertEqual(r, response_ok)
            self.assertEqual(
                request.headers['Authorization'],
                'Negotiate GSSRESPONSE')
            connection.send.assert_called_with(request)
            raw.release_conn.assert_called_with()
            clientInit_complete.assert_called_with(
                "HTTP@www.example.org",
                gssflags=(
                    kerberos.GSS_C_MUTUAL_FLAG |
                    kerberos.GSS_C_SEQUENCE_FLAG),
                principal=None)
            clientStep_continue.assert_called_with("CTX", "token")
            clientResponse.assert_called_with("CTX")

    def test_handle_response_401_rejected(self):
        # Get a 401 from server, authenticate, and get another 401 back.
        # Ensure there is no infinite recursion.
        with patch.multiple(kerberos_module_name,
                            authGSSClientInit=clientInit_complete,
                            authGSSClientResponse=clientResponse,
                            authGSSClientStep=clientStep_continue):

            connection = Mock()

            def connection_send(self, *args, **kwargs):
                reject = requests.Response()
                reject.url = "http://www.example.org/"
                reject.status_code = 401
                reject.connection = connection
                return reject

            connection.send.side_effect = connection_send

            raw = Mock()
            raw.release_conn.return_value = None

            request = requests.Request()
            response = requests.Response()
            response.request = request
            response.url = "http://www.example.org/"
            response.headers = {'www-authenticate': 'negotiate token'}
            response.status_code = 401
            response.connection = connection
            response._content = ""
            response.raw = raw

            auth = requests_kerberos.HTTPKerberosAuth()

            r = auth.handle_response(response)

            self.assertEqual(r.status_code, 401)
            self.assertEqual(request.headers['Authorization'],
                             'Negotiate GSSRESPONSE')
            connection.send.assert_called_with(request)
            raw.release_conn.assert_called_with()
            clientInit_complete.assert_called_with(
                "HTTP@www.example.org",
                gssflags=(
                    kerberos.GSS_C_MUTUAL_FLAG |
                    kerberos.GSS_C_SEQUENCE_FLAG),
                principal=None)
            clientStep_continue.assert_called_with("CTX", "token")
            clientResponse.assert_called_with("CTX")

    def test_generate_request_header_custom_service(self):
        with patch.multiple(kerberos_module_name,
                            authGSSClientInit=clientInit_complete,
                            authGSSClientResponse=clientResponse,
                            authGSSClientStep=clientStep_continue):
            response = requests.Response()
            response.url = "http://www.example.org/"
            response.headers = {'www-authenticate': 'negotiate token'}
            host = urlparse(response.url).hostname
            auth = requests_kerberos.HTTPKerberosAuth(service="barfoo")
            auth.generate_request_header(response, host),
            clientInit_complete.assert_called_with(
                "barfoo@www.example.org",
                gssflags=(
                    kerberos.GSS_C_MUTUAL_FLAG |
                    kerberos.GSS_C_SEQUENCE_FLAG),
                principal=None)

    def test_delegation(self):
        with patch.multiple(kerberos_module_name,
                            authGSSClientInit=clientInit_complete,
                            authGSSClientResponse=clientResponse,
                            authGSSClientStep=clientStep_continue):

            response_ok = requests.Response()
            response_ok.url = "http://www.example.org/"
            response_ok.status_code = 200
            response_ok.headers = {'www-authenticate': 'negotiate servertoken'}

            connection = Mock()
            connection.send = Mock(return_value=response_ok)

            raw = Mock()
            raw.release_conn = Mock(return_value=None)

            request = requests.Request()
            response = requests.Response()
            response.request = request
            response.url = "http://www.example.org/"
            response.headers = {'www-authenticate': 'negotiate token'}
            response.status_code = 401
            response.connection = connection
            response._content = ""
            response.raw = raw
            auth = requests_kerberos.HTTPKerberosAuth(1, "HTTP", True)
            r = auth.authenticate_user(response)

            self.assertTrue(response in r.history)
            self.assertEqual(r, response_ok)
            self.assertEqual(
                request.headers['Authorization'],
                'Negotiate GSSRESPONSE')
            connection.send.assert_called_with(request)
            raw.release_conn.assert_called_with()
            clientInit_complete.assert_called_with(
                "HTTP@www.example.org",
                gssflags=(
                    kerberos.GSS_C_MUTUAL_FLAG |
                    kerberos.GSS_C_SEQUENCE_FLAG |
                    kerberos.GSS_C_DELEG_FLAG),
                principal=None
                )
            clientStep_continue.assert_called_with("CTX", "token")
            clientResponse.assert_called_with("CTX")

    def test_principal_override(self):
        with patch.multiple(kerberos_module_name,
                            authGSSClientInit=clientInit_complete,
                            authGSSClientResponse=clientResponse,
                            authGSSClientStep=clientStep_continue):
            response = requests.Response()
            response.url = "http://www.example.org/"
            response.headers = {'www-authenticate': 'negotiate token'}
            host = urlparse(response.url).hostname
            auth = requests_kerberos.HTTPKerberosAuth(principal="user@REALM")
            auth.generate_request_header(response, host)
            clientInit_complete.assert_called_with(
                "HTTP@www.example.org",
                gssflags=(
                    kerberos.GSS_C_MUTUAL_FLAG |
                    kerberos.GSS_C_SEQUENCE_FLAG),
                principal="user@REALM")

    def test_realm_override(self):
        with patch.multiple(kerberos_module_name,
                            authGSSClientInit=clientInit_complete,
                            authGSSClientResponse=clientResponse,
                            authGSSClientStep=clientStep_continue):
            response = requests.Response()
            response.url = "http://www.example.org/"
            response.headers = {'www-authenticate': 'negotiate token'}
            host = urlparse(response.url).hostname
            auth = requests_kerberos.HTTPKerberosAuth(hostname_override="otherhost.otherdomain.org")
            auth.generate_request_header(response, host)
            clientInit_complete.assert_called_with(
                "HTTP@otherhost.otherdomain.org",
                gssflags=(
                    kerberos.GSS_C_MUTUAL_FLAG |
                    kerberos.GSS_C_SEQUENCE_FLAG),
                principal=None)


class TestCertificateHash(unittest.TestCase):

    def test_rsa_md5(self):
        cert_der = b'MIIDGzCCAgOgAwIBAgIQJzshhViMG5hLHIJHxa+TcTANBgkqhkiG9w0' \
                   b'BAQQFADAVMRMwEQYDVQQDDApTRVJWRVIyMDE2MB4XDTE3MDUzMDA4MD' \
                   b'MxNloXDTE4MDUzMDA4MjMxNlowFTETMBEGA1UEAwwKU0VSVkVSMjAxN' \
                   b'jCCASIwDQYJKoZIhvcNAQEBBQADggEPADCCAQoCggEBAN9N5GAzI7uq' \
                   b'AVlI6vUqhY5+EZWCWWGRwR3FT2DEXE5++AiJxXO0i0ZfAkLu7UggtBe' \
                   b'QwVNkaPD27EYzVUhy1iDo37BrFcLNpfjsjj8wVjaSmQmqvLvrvEh/BT' \
                   b'C5SBgDrk2+hiMh9PrpJoB3QAMDinz5aW0rEXMKitPBBiADrczyYrliF' \
                   b'AlEU6pTlKEKDUAeP7dKOBlDbCYvBxKnR3ddVH74I5T2SmNBq5gzkbKP' \
                   b'nlCXdHLZSh74USu93rKDZQF8YzdTO5dcBreJDJsntyj1o49w9WCt6M7' \
                   b'+pg6vKvE+tRbpCm7kXq5B9PDi42Nb6//MzNaMYf9V7v5MHapvVSv3+y' \
                   b'sCAwEAAaNnMGUwDgYDVR0PAQH/BAQDAgWgMB0GA1UdJQQWMBQGCCsGA' \
                   b'QUFBwMCBggrBgEFBQcDATAVBgNVHREEDjAMggpTRVJWRVIyMDE2MB0G' \
                   b'A1UdDgQWBBTh4L2Clr9ber6yfY3JFS3wiECL4DANBgkqhkiG9w0BAQQ' \
                   b'FAAOCAQEA0JK/SL7SP9/nvqWp52vnsxVefTFehThle5DLzagmms/9gu' \
                   b'oSE2I9XkQIttFMprPosaIZWt7WP42uGcZmoZOzU8kFFYJMfg9Ovyca+' \
                   b'gnG28jDUMF1E74KrC7uynJiQJ4vPy8ne7F3XJ592LsNJmK577l42gAW' \
                   b'u08p3TvEJFNHy2dBk/IwZp0HIPr9+JcPf7v0uL6lK930xHJHP56XLzN' \
                   b'YG8vCMpJFR7wVZp3rXkJQUy3GxyHPJPjS8S43I9j+PoyioWIMEotq2+' \
                   b'q0IpXU/KeNFkdGV6VPCmzhykijExOMwO6doUzIUM8orv9jYLHXYC+i6' \
                   b'IFKSb6runxF1MAik+GCSA=='

        expected_hash = b'\x23\x34\xB8\x47\x6C\xBF\x4E\x6D\xFC\x76\x6A\x5D' \
                        b'\x5A\x30\xD6\x64\x9C\x01\xBA\xE1\x66\x2A\x5C\x3A' \
                        b'\x13\x02\xA9\x68\xD7\xC6\xB0\xF6'
        actual_hash = _get_certificate_hash(base64.b64decode(cert_der))
        assert actual_hash == expected_hash

    def test_rsa_sha1(self):
        cert_der = b'MIIDGzCCAgOgAwIBAgIQJg/Mf5sR55xApJRK+kabbTANBgkqhkiG9w0' \
                   b'BAQUFADAVMRMwEQYDVQQDDApTRVJWRVIyMDE2MB4XDTE3MDUzMDA4MD' \
                   b'MxNloXDTE4MDUzMDA4MjMxNlowFTETMBEGA1UEAwwKU0VSVkVSMjAxN' \
                   b'jCCASIwDQYJKoZIhvcNAQEBBQADggEPADCCAQoCggEBALPKwYikjbzL' \
                   b'Lo6JtS6cyytdMMjSrggDoTnRUKauC5/izoYJd+2YVR5YqnluBJZpoFp' \
                   b'hkCgFFohUOU7qUsI1SkuGnjI8RmWTrrDsSy62BrfX+AXkoPlXo6IpHz' \
                   b'HaEPxjHJdUACpn8QVWTPmdAhwTwQkeUutrm3EOVnKPX4bafNYeAyj7/' \
                   b'AGEplgibuXT4/ehbzGKOkRN3ds/pZuf0xc4Q2+gtXn20tQIUt7t6iwh' \
                   b'nEWjIgopFL/hX/r5q5MpF6stc1XgIwJjEzqMp76w/HUQVqaYneU4qSG' \
                   b'f90ANK/TQ3aDbUNtMC/ULtIfHqHIW4POuBYXaWBsqalJL2VL3YYkKTU' \
                   b'sCAwEAAaNnMGUwDgYDVR0PAQH/BAQDAgWgMB0GA1UdJQQWMBQGCCsGA' \
                   b'QUFBwMCBggrBgEFBQcDATAVBgNVHREEDjAMggpTRVJWRVIyMDE2MB0G' \
                   b'A1UdDgQWBBS1jgojcjPu9vqeP1uSKuiIonGwAjANBgkqhkiG9w0BAQU' \
                   b'FAAOCAQEAKjHL6k5Dv/Zb7dvbYEZyx0wVhjHkCTpT3xstI3+TjfAFsu' \
                   b'3zMmyFqFqzmr4pWZ/rHc3ObD4pEa24kP9hfB8nmr8oHMLebGmvkzh5h' \
                   b'0GYc4dIH7Ky1yfQN51hi7/X5iN7jnnBoCJTTlgeBVYDOEBXhfXi3cLT' \
                   b'u3d7nz2heyNq07gFP8iN7MfqdPZndVDYY82imLgsgar9w5d+fvnYM+k' \
                   b'XWItNNCUH18M26Obp4Es/Qogo/E70uqkMHost2D+tww/7woXi36X3w/' \
                   b'D2yBDyrJMJKZLmDgfpNIeCimncTOzi2IhzqJiOY/4XPsVN/Xqv0/dzG' \
                   b'TDdI11kPLq4EiwxvPanCg=='

        expected_hash = b'\x14\xCF\xE8\xE4\xB3\x32\xB2\x0A\x34\x3F\xC8\x40' \
                        b'\xB1\x8F\x9F\x6F\x78\x92\x6A\xFE\x7E\xC3\xE7\xB8' \
                        b'\xE2\x89\x69\x61\x9B\x1E\x8F\x3E'
        actual_hash = _get_certificate_hash(base64.b64decode(cert_der))
        assert actual_hash == expected_hash

    def test_rsa_sha256(self):
        cert_der = b'MIIDGzCCAgOgAwIBAgIQWkeAtqoFg6pNWF7xC4YXhTANBgkqhkiG9w0' \
                   b'BAQsFADAVMRMwEQYDVQQDDApTRVJWRVIyMDE2MB4XDTE3MDUyNzA5MD' \
                   b'I0NFoXDTE4MDUyNzA5MjI0NFowFTETMBEGA1UEAwwKU0VSVkVSMjAxN' \
                   b'jCCASIwDQYJKoZIhvcNAQEBBQADggEPADCCAQoCggEBALIPKM5uykFy' \
                   b'NmVoLyvPSXGk15ZDqjYi3AbUxVFwCkVImqhefLATit3PkTUYFtAT+TC' \
                   b'AwK2E4lOu1XHM+Tmp2KIOnq2oUR8qMEvfxYThEf1MHxkctFljFssZ9N' \
                   b'vASDD4lzw8r0Bhl+E5PhR22Eu1Wago5bvIldojkwG+WBxPQv3ZR546L' \
                   b'MUZNaBXC0RhuGj5w83lbVz75qM98wvv1ekfZYAP7lrVyHxqCTPDomEU' \
                   b'I45tQQZHCZl5nRx1fPCyyYfcfqvFlLWD4Q3PZAbnw6mi0MiWJbGYKME' \
                   b'1XGicjqyn/zM9XKA1t/JzChS2bxf6rsyA9I7ibdRHUxsm1JgKry2jfW' \
                   b'0CAwEAAaNnMGUwDgYDVR0PAQH/BAQDAgWgMB0GA1UdJQQWMBQGCCsGA' \
                   b'QUFBwMCBggrBgEFBQcDATAVBgNVHREEDjAMggpTRVJWRVIyMDE2MB0G' \
                   b'A1UdDgQWBBQabLGWg1sn7AXPwYPyfE0ER921ZDANBgkqhkiG9w0BAQs' \
                   b'FAAOCAQEAnRohyl6ZmOsTWCtxOJx5A8yr//NweXKwWWmFQXRmCb4bMC' \
                   b'xhD4zqLDf5P6RotGV0I/SHvqz+pAtJuwmr+iyAF6WTzo3164LCfnQEu' \
                   b'psfrrfMkf3txgDwQkA0oPAw3HEwOnR+tzprw3Yg9x6UoZEhi4XqP9AX' \
                   b'R49jU92KrNXJcPlz5MbkzNo5t9nr2f8q39b5HBjaiBJxzdM1hxqsbfD' \
                   b'KirTYbkUgPlVOo/NDmopPPb8IX8ubj/XETZG2jixD0zahgcZ1vdr/iZ' \
                   b'+50WSXKN2TAKBO2fwoK+2/zIWrGRxJTARfQdF+fGKuj+AERIFNh88HW' \
                   b'xSDYjHQAaFMcfdUpa9GGQ=='

        expected_hash = b'\x99\x6F\x3E\xEA\x81\x2C\x18\x70\xE3\x05\x49\xFF' \
                        b'\x9B\x86\xCD\x87\xA8\x90\xB6\xD8\xDF\xDF\x4A\x81' \
                        b'\xBE\xF9\x67\x59\x70\xDA\xDB\x26'
        actual_hash = _get_certificate_hash(base64.b64decode(cert_der))
        assert actual_hash == expected_hash

    def test_rsa_sha384(self):
        cert_der = b'MIIDGzCCAgOgAwIBAgIQEmj1prSSQYRL2zYBEjsm5jANBgkqhkiG9w0' \
                   b'BAQwFADAVMRMwEQYDVQQDDApTRVJWRVIyMDE2MB4XDTE3MDUzMDA4MD' \
                   b'MxN1oXDTE4MDUzMDA4MjMxN1owFTETMBEGA1UEAwwKU0VSVkVSMjAxN' \
                   b'jCCASIwDQYJKoZIhvcNAQEBBQADggEPADCCAQoCggEBAKsK5NvHi4xO' \
                   b'081fRLMmPqKsKaHvXgPRykLA0SmKxpGJHfTAZzxojHVeVwOm87IvQj2' \
                   b'JUh/yrRwSi5Oqrvqx29l2IC/qQt2xkAQsO51/EWkMQ5OSJsl1MN3NXW' \
                   b'eRTKVoUuJzBs8XLmeraxQcBPyyLhq+WpMl/Q4ZDn1FrUEZfxV0POXgU' \
                   b'dI3ApuQNRtJOb6iteBIoQyMlnof0RswBUnkiWCA/+/nzR0j33j47IfL' \
                   b'nkmU4RtqkBlO13f6+e1GZ4lEcQVI2yZq4Zgu5VVGAFU2lQZ3aEVMTu9' \
                   b'8HEqD6heyNp2on5G/K/DCrGWYCBiASjnX3wiSz0BYv8f3HhCgIyVKhJ' \
                   b'8CAwEAAaNnMGUwDgYDVR0PAQH/BAQDAgWgMB0GA1UdJQQWMBQGCCsGA' \
                   b'QUFBwMCBggrBgEFBQcDATAVBgNVHREEDjAMggpTRVJWRVIyMDE2MB0G' \
                   b'A1UdDgQWBBQS/SI61S2UE8xwSgHxbkCTpZXo4TANBgkqhkiG9w0BAQw' \
                   b'FAAOCAQEAMVV/WMXd9w4jtDfSrIsKaWKGtHtiMPpAJibXmSakBRwLOn' \
                   b'5ZGXL2bWI/Ac2J2Y7bSzs1im2ifwmEqwzzqnpVKShIkZmtij0LS0SEr' \
                   b'6Fw5IrK8tD6SH+lMMXUTvp4/lLQlgRCwOWxry/YhQSnuprx8IfSPvil' \
                   b'kwZ0Ysim4Aa+X5ojlhHpWB53edX+lFrmR1YWValBnQ5DvnDyFyLR6II' \
                   b'Ialp4vmkzI9e3/eOgSArksizAhpXpC9dxQBiHXdhredN0X+1BVzbgzV' \
                   b'hQBEwgnAIPa+B68oDILaV0V8hvxrP6jFM4IrKoGS1cq0B+Ns0zkG7ZA' \
                   b'2Q0W+3nVwSxIr6bd6hw7g=='

        expected_hash = b'\x34\xF3\x03\xC9\x95\x28\x6F\x4B\x21\x4A\x9B\xA6' \
                        b'\x43\x5B\x69\xB5\x1E\xCF\x37\x58\xEA\xBC\x2A\x14' \
                        b'\xD7\xA4\x3F\xD2\x37\xDC\x2B\x1A\x1A\xD9\x11\x1C' \
                        b'\x5C\x96\x5E\x10\x75\x07\xCB\x41\x98\xC0\x9F\xEC'
        actual_hash = _get_certificate_hash(base64.b64decode(cert_der))
        assert actual_hash == expected_hash

    def test_rsa_sha512(self):
        cert_der = b'MIIDGzCCAgOgAwIBAgIQUDHcKGevZohJV+TkIIYC1DANBgkqhkiG9w0' \
                   b'BAQ0FADAVMRMwEQYDVQQDDApTRVJWRVIyMDE2MB4XDTE3MDUzMDA4MD' \
                   b'MxN1oXDTE4MDUzMDA4MjMxN1owFTETMBEGA1UEAwwKU0VSVkVSMjAxN' \
                   b'jCCASIwDQYJKoZIhvcNAQEBBQADggEPADCCAQoCggEBAKr9bo/XXvHt' \
                   b'D6Qnhb1wyLg9lDQxxe/enH49LQihtVTZMwGf2010h81QrRUe/bkHTvw' \
                   b'K22s2lqj3fUpGxtEbYFWLAHxv6IFnIKd+Zi1zaCPGfas9ekqCSj3vZQ' \
                   b'j7lCJVGUGuuqnSDvsed6g2Pz/g6mJUa+TzjxN+8wU5oj5YVUK+aing1' \
                   b'zPSA2MDCfx3+YzjxVwNoGixOz6Yx9ijT4pUsAYQAf1o9R+6W1/IpGgu' \
                   b'oax714QILT9heqIowwlHzlUZc1UAYs0/JA4CbDZaw9hlJyzMqe/aE46' \
                   b'efqPDOpO3vCpOSRcSyzh02WijPvEEaPejQRWg8RX93othZ615MT7dqp' \
                   b'ECAwEAAaNnMGUwDgYDVR0PAQH/BAQDAgWgMB0GA1UdJQQWMBQGCCsGA' \
                   b'QUFBwMCBggrBgEFBQcDATAVBgNVHREEDjAMggpTRVJWRVIyMDE2MB0G' \
                   b'A1UdDgQWBBTgod3R6vejt6kOASAApA19xIG6kTANBgkqhkiG9w0BAQ0' \
                   b'FAAOCAQEAVfz0okK2bh3OQE8cWNbJ5PjJRSAJEqVUvYaTlS0Nqkyuaj' \
                   b'gicP3hb/pF8FvaVaB6r7LqgBxyW5NNL1xwdNLt60M2zaULL6Fhm1vzM' \
                   b'sSMc2ynkyN4++ODwii674YcQAnkUh+ZGIx+CTdZBWJfVM9dZb7QjgBT' \
                   b'nVukeFwN2EOOBSpiQSBpcoeJEEAq9csDVRhEfcB8Wtz7TTItgOVsilY' \
                   b'dQY56ON5XszjCki6UA3GwdQbBEHjWF2WERqXWrojrSSNOYDvxM5mrEx' \
                   b'sG1npzUTsaIr9w8ty1beh/2aToCMREvpiPFOXnVV/ovHMU1lFQTNeQ0' \
                   b'OI7elR0nJ0peai30eMpQQ=='

        expected_hash = b'\x55\x6E\x1C\x17\x84\xE3\xB9\x57\x37\x0B\x7F\x54' \
                        b'\x4F\x62\xC5\x33\xCB\x2C\xA5\xC1\xDA\xE0\x70\x6F' \
                        b'\xAE\xF0\x05\x44\xE1\xAD\x2B\x76\xFF\x25\xCF\xBE' \
                        b'\x69\xB1\xC4\xE6\x30\xC3\xBB\x02\x07\xDF\x11\x31' \
                        b'\x4C\x67\x38\xBC\xAE\xD7\xE0\x71\xD7\xBF\xBF\x2C' \
                        b'\x9D\xFA\xB8\x5D'
        actual_hash = _get_certificate_hash(base64.b64decode(cert_der))
        assert actual_hash == expected_hash

    def test_ecdsa_sha1(self):
        cert_der = b'MIIBjjCCATSgAwIBAgIQRCJw7nbtvJ5F8wikRmwgizAJBgcqhkjOPQQ' \
                   b'BMBUxEzARBgNVBAMMClNFUlZFUjIwMTYwHhcNMTcwNTMwMDgwMzE3Wh' \
                   b'cNMTgwNTMwMDgyMzE3WjAVMRMwEQYDVQQDDApTRVJWRVIyMDE2MFkwE' \
                   b'wYHKoZIzj0CAQYIKoZIzj0DAQcDQgAEk3fOh178kRglmnPKe9K/mbgi' \
                   b'gf8YgNq62rF2EpfzpyQY0eGw4xnmKDG73aZ+ATSlV2IybxiUVsKyMUn' \
                   b'LhPfvmaNnMGUwDgYDVR0PAQH/BAQDAgWgMB0GA1UdJQQWMBQGCCsGAQ' \
                   b'UFBwMCBggrBgEFBQcDATAVBgNVHREEDjAMggpTRVJWRVIyMDE2MB0GA' \
                   b'1UdDgQWBBQSK8qwmiQmyAWWya3FxQDj9wqQAzAJBgcqhkjOPQQBA0kA' \
                   b'MEYCIQCiOsP56Iqo+cHRvCp2toj65Mgxo/PQY1tn+S3WH4RJFQIhAJe' \
                   b'gGQuaPWg6aCWV+2+6pNCNMdg/Nix+mMOJ88qCBNHi'

        expected_hash = b'\x1E\xC9\xAD\x46\xDE\xE9\x34\x0E\x45\x03\xCF\xFD' \
                        b'\xB5\xCD\x81\x0C\xB2\x6B\x77\x8F\x46\xBE\x95\xD5' \
                        b'\xEA\xF9\x99\xDC\xB1\xC4\x5E\xDA'
        actual_hash = _get_certificate_hash(base64.b64decode(cert_der))
        assert actual_hash == expected_hash

    def test_ecdsa_sha256(self):
        cert_der = b'MIIBjzCCATWgAwIBAgIQeNQTxkMgq4BF9tKogIGXUTAKBggqhkjOPQQ' \
                   b'DAjAVMRMwEQYDVQQDDApTRVJWRVIyMDE2MB4XDTE3MDUzMDA4MDMxN1' \
                   b'oXDTE4MDUzMDA4MjMxN1owFTETMBEGA1UEAwwKU0VSVkVSMjAxNjBZM' \
                   b'BMGByqGSM49AgEGCCqGSM49AwEHA0IABDAfXTLOaC3ElgErlgk2tBlM' \
                   b'wf9XmGlGBw4vBtMJap1hAqbsdxFm6rhK3QU8PFFpv8Z/AtRG7ba3UwQ' \
                   b'prkssClejZzBlMA4GA1UdDwEB/wQEAwIFoDAdBgNVHSUEFjAUBggrBg' \
                   b'EFBQcDAgYIKwYBBQUHAwEwFQYDVR0RBA4wDIIKU0VSVkVSMjAxNjAdB' \
                   b'gNVHQ4EFgQUnFDE8824TYAiBeX4fghEEg33UgYwCgYIKoZIzj0EAwID' \
                   b'SAAwRQIhAK3rXA4/0i6nm/U7bi6y618Ci2Is8++M3tYIXnEsA7zSAiA' \
                   b'w2s6bJoI+D7Xaey0Hp0gkks9z55y976keIEI+n3qkzw=='

        expected_hash = b'\xFE\xCF\x1B\x25\x85\x44\x99\x90\xD9\xE3\xB2\xC9' \
                        b'\x2D\x3F\x59\x7E\xC8\x35\x4E\x12\x4E\xDA\x75\x1D' \
                        b'\x94\x83\x7C\x2C\x89\xA2\xC1\x55'
        actual_hash = _get_certificate_hash(base64.b64decode(cert_der))
        assert actual_hash == expected_hash

    def test_ecdsa_sha384(self):
        cert_der = b'MIIBjzCCATWgAwIBAgIQcO3/jALdQ6BOAoaoseLSCjAKBggqhkjOPQQ' \
                   b'DAzAVMRMwEQYDVQQDDApTRVJWRVIyMDE2MB4XDTE3MDUzMDA4MDMxOF' \
                   b'oXDTE4MDUzMDA4MjMxOFowFTETMBEGA1UEAwwKU0VSVkVSMjAxNjBZM' \
                   b'BMGByqGSM49AgEGCCqGSM49AwEHA0IABJLjZH274heB/8PhmhWWCIVQ' \
                   b'Wle1hBZEN3Tk2yWSKaz9pz1bjwb9t79lVpQE9tvGL0zP9AqJYHcVOO9' \
                   b'YG9trqfejZzBlMA4GA1UdDwEB/wQEAwIFoDAdBgNVHSUEFjAUBggrBg' \
                   b'EFBQcDAgYIKwYBBQUHAwEwFQYDVR0RBA4wDIIKU0VSVkVSMjAxNjAdB' \
                   b'gNVHQ4EFgQUkRajoFr8qZ/8L8rKB3zGiGolDygwCgYIKoZIzj0EAwMD' \
                   b'SAAwRQIgfi8dAxXljCMSvngtDtagGCTGBs7Xxh8Z3WX6ZwJZsHYCIQC' \
                   b'D4iNReh1afXKYC0ipjXWAIkiihnEEycCIQMbkMNst7A=='

        expected_hash = b'\xD2\x98\x7A\xD8\xF2\x0E\x83\x16\xA8\x31\x26\x1B' \
                        b'\x74\xEF\x7B\x3E\x55\x15\x5D\x09\x22\xE0\x7F\xFE' \
                        b'\x54\x62\x08\x06\x98\x2B\x68\xA7\x3A\x5E\x3C\x47' \
                        b'\x8B\xAA\x5E\x77\x14\x13\x5C\xB2\x6D\x98\x07\x49'
        actual_hash = _get_certificate_hash(base64.b64decode(cert_der))
        assert actual_hash == expected_hash

    def test_ecdsa_sha512(self):
        cert_der = b'MIIBjjCCATWgAwIBAgIQHVj2AGEwd6pOOSbcf0skQDAKBggqhkjOPQQ' \
                   b'DBDAVMRMwEQYDVQQDDApTRVJWRVIyMDE2MB4XDTE3MDUzMDA3NTUzOV' \
                   b'oXDTE4MDUzMDA4MTUzOVowFTETMBEGA1UEAwwKU0VSVkVSMjAxNjBZM' \
                   b'BMGByqGSM49AgEGCCqGSM49AwEHA0IABL8d9S++MFpfzeH8B3vG/PjA' \
                   b'AWg8tGJVgsMw9nR+OfC9ltbTUwhB+yPk3JPcfW/bqsyeUgq4//LhaSp' \
                   b'lOWFNaNqjZzBlMA4GA1UdDwEB/wQEAwIFoDAdBgNVHSUEFjAUBggrBg' \
                   b'EFBQcDAgYIKwYBBQUHAwEwFQYDVR0RBA4wDIIKU0VSVkVSMjAxNjAdB' \
                   b'gNVHQ4EFgQUKUkCgLlxoeai0EtQrZth1/BSc5kwCgYIKoZIzj0EAwQD' \
                   b'RwAwRAIgRrV7CLpDG7KueyFA3ZDced9dPOcv2Eydx/hgrfxYEcYCIBQ' \
                   b'D35JvzmqU05kSFV5eTvkhkaDObd7V55vokhm31+Li'

        expected_hash = b'\xE5\xCB\x68\xB2\xF8\x43\xD6\x3B\xF4\x0B\xCB\x20' \
                        b'\x07\x60\x8F\x81\x97\x61\x83\x92\x78\x3F\x23\x30' \
                        b'\xE5\xEF\x19\xA5\xBD\x8F\x0B\x2F\xAA\xC8\x61\x85' \
                        b'\x5F\xBB\x63\xA2\x21\xCC\x46\xFC\x1E\x22\x6A\x07' \
                        b'\x24\x11\xAF\x17\x5D\xDE\x47\x92\x81\xE0\x06\x87' \
                        b'\x8B\x34\x80\x59'
        actual_hash = _get_certificate_hash(base64.b64decode(cert_der))
        assert actual_hash == expected_hash

    def test_invalid_signature_algorithm(self):
        # Manually edited from test_ecdsa_sha512 to change the OID to '1.2.840.10045.4.3.5'
        cert_der = b'MIIBjjCCATWgAwIBAgIQHVj2AGEwd6pOOSbcf0skQDAKBggqhkjOPQQ' \
                   b'DBTAVMRMwEQYDVQQDDApTRVJWRVIyMDE2MB4XDTE3MDUzMDA3NTUzOV' \
                   b'oXDTE4MDUzMDA4MTUzOVowFTETMBEGA1UEAwwKU0VSVkVSMjAxNjBZM' \
                   b'BMGByqGSM49AgEGCCqGSM49AwEHA0IABL8d9S++MFpfzeH8B3vG/PjA' \
                   b'AWg8tGJVgsMw9nR+OfC9ltbTUwhB+yPk3JPcfW/bqsyeUgq4//LhaSp' \
                   b'lOWFNaNqjZzBlMA4GA1UdDwEB/wQEAwIFoDAdBgNVHSUEFjAUBggrBg' \
                   b'EFBQcDAgYIKwYBBQUHAwEwFQYDVR0RBA4wDIIKU0VSVkVSMjAxNjAdB' \
                   b'gNVHQ4EFgQUKUkCgLlxoeai0EtQrZth1/BSc5kwCgYIKoZIzj0EAwUD' \
                   b'RwAwRAIgRrV7CLpDG7KueyFA3ZDced9dPOcv2Eydx/hgrfxYEcYCIBQ' \
                   b'D35JvzmqU05kSFV5eTvkhkaDObd7V55vokhm31+Li'

        expected_hash = None
        expected_warning = "Failed to get signature algorithm from " \
                           "certificate, unable to pass channel bindings:"

        with warnings.catch_warnings(record=True) as w:
            warnings.simplefilter("always")
            actual_hash = _get_certificate_hash(base64.b64decode(cert_der))
            assert actual_hash == expected_hash
            assert expected_warning in str(w[-1].message)


if __name__ == '__main__':
    unittest.main()