feat: add mtls support (#367)

* feat: add mtls support

* update

* update

* update

* update

* update

google/cloud/storage/_http.py

@@ -15,27 +15,42 @@
 """Create / interact with Google Cloud Storage connections."""
 
 import functools
+import os
+import pkg_resources
 
 from google.cloud import _http
 
 from google.cloud.storage import __version__
 
 
+if os.getenv("GOOGLE_API_USE_CLIENT_CERTIFICATE") == "true":  # pragma: NO COVER
+    release = pkg_resources.get_distribution("google-cloud-core").parsed_version
+    if release < pkg_resources.parse_version("1.6.0"):
+        raise ImportError("google-cloud-core >= 1.6.0 is required to use mTLS feature")
+
+
 class Connection(_http.JSONConnection):
-    """A connection to Google Cloud Storage via the JSON REST API.
+    """A connection to Google Cloud Storage via the JSON REST API. Mutual TLS feature will be
+    enabled if `GOOGLE_API_USE_CLIENT_CERTIFICATE` environment variable is set to "true".
 
     :type client: :class:`~google.cloud.storage.client.Client`
     :param client: The client that owns the current connection.
 
     :type client_info: :class:`~google.api_core.client_info.ClientInfo`
     :param client_info: (Optional) instance used to generate user agent.
+
+    :type api_endpoint: str
+    :param api_endpoint: (Optional) api endpoint to use.
     """
 
     DEFAULT_API_ENDPOINT = "https://storage.googleapis.com"
+    DEFAULT_API_MTLS_ENDPOINT = "https://storage.mtls.googleapis.com"
 
-    def __init__(self, client, client_info=None, api_endpoint=DEFAULT_API_ENDPOINT):
+    def __init__(self, client, client_info=None, api_endpoint=None):
         super(Connection, self).__init__(client, client_info)
-        self.API_BASE_URL = api_endpoint
+        self.API_BASE_URL = api_endpoint or self.DEFAULT_API_ENDPOINT
+        self.API_BASE_MTLS_URL = self.DEFAULT_API_MTLS_ENDPOINT
+        self.ALLOW_AUTO_SWITCH_TO_MTLS_URL = api_endpoint is None
         self._client_info.client_library_version = __version__
 
         # TODO: When metrics all use gccl, this should be removed #9552

google/cloud/storage/blob.py

@@ -830,9 +830,8 @@ def _get_download_url(
         """
         name_value_pairs = []
         if self.media_link is None:
-            base_url = _DOWNLOAD_URL_TEMPLATE.format(
-                hostname=client._connection.API_BASE_URL, path=self.path
-            )
+            hostname = _get_host_name(client._connection)
+            base_url = _DOWNLOAD_URL_TEMPLATE.format(hostname=hostname, path=self.path)
             if self.generation is not None:
                 name_value_pairs.append(("generation", "{:d}".format(self.generation)))
         else:
@@ -1685,8 +1684,9 @@ def _do_multipart_upload(
         info = self._get_upload_arguments(content_type)
         headers, object_metadata, content_type = info
 
+        hostname = _get_host_name(client._connection)
         base_url = _MULTIPART_URL_TEMPLATE.format(
-            hostname=client._connection.API_BASE_URL, bucket_path=self.bucket.path
+            hostname=hostname, bucket_path=self.bucket.path
         )
         name_value_pairs = []
 
@@ -1866,8 +1866,9 @@ def _initiate_resumable_upload(
         if extra_headers is not None:
             headers.update(extra_headers)
 
+        hostname = _get_host_name(client._connection)
         base_url = _RESUMABLE_URL_TEMPLATE.format(
-            hostname=client._connection.API_BASE_URL, bucket_path=self.bucket.path
+            hostname=hostname, bucket_path=self.bucket.path
         )
         name_value_pairs = []
 
@@ -3798,6 +3799,25 @@ def custom_time(self, value):
         self._patch_property("customTime", value)
 
 
+def _get_host_name(connection):
+    """Returns the host name from the given connection.
+
+    :type connection: :class:`~google.cloud.storage._http.Connection`
+    :param connection: The connection object.
+
+    :rtype: str
+    :returns: The host name.
+    """
+    # TODO: After google-cloud-core 1.6.0 is stable and we upgrade it
+    # to 1.6.0 in setup.py, we no longer need to check the attribute
+    # existence. We can simply return connection.get_api_base_url_for_mtls().
+    return (
+        connection.API_BASE_URL
+        if not hasattr(connection, "get_api_base_url_for_mtls")
+        else connection.get_api_base_url_for_mtls()
+    )
+
+
 def _get_encryption_headers(key, source=False):
     """Builds customer encryption key headers
 

google/cloud/storage/client.py

@@ -32,6 +32,7 @@
 from google.cloud.client import ClientWithProject
 from google.cloud.exceptions import NotFound
 from google.cloud.storage._helpers import _get_storage_host
+from google.cloud.storage._helpers import _DEFAULT_STORAGE_HOST
 from google.cloud.storage._helpers import _bucket_bound_hostname_url
 from google.cloud.storage._http import Connection
 from google.cloud.storage._signing import (
@@ -127,7 +128,14 @@ def __init__(
 
         kw_args = {"client_info": client_info}
 
-        kw_args["api_endpoint"] = _get_storage_host()
+        # `api_endpoint` should be only set by the user via `client_options`,
+        # or if the _get_storage_host() returns a non-default value.
+        # `api_endpoint` plays an important role for mTLS, if it is not set,
+        # then mTLS logic will be applied to decide which endpoint will be used.
+        storage_host = _get_storage_host()
+        kw_args["api_endpoint"] = (
+            storage_host if storage_host != _DEFAULT_STORAGE_HOST else None
+        )
 
         if client_options:
             if type(client_options) == dict:

noxfile.py

@@ -107,6 +107,9 @@ def system(session):
     # Sanity check: Only run tests if the environment variable is set.
     if not os.environ.get("GOOGLE_APPLICATION_CREDENTIALS", ""):
         session.skip("Credentials must be set via environment variable")
+    # mTLS tests requires pyopenssl.
+    if os.environ.get("GOOGLE_API_USE_CLIENT_CERTIFICATE", "") == "true":
+        session.install("pyopenssl")
 
     system_test_exists = os.path.exists(system_test_path)
     system_test_folder_exists = os.path.exists(system_test_folder_path)

tests/system/test_system.py

@@ -81,6 +81,7 @@ class Config(object):
 
     CLIENT = None
     TEST_BUCKET = None
+    TESTING_MTLS = False
 
 
 def setUpModule():
@@ -91,6 +92,10 @@ def setUpModule():
     Config.TEST_BUCKET = Config.CLIENT.bucket(bucket_name)
     Config.TEST_BUCKET.versioning_enabled = True
     retry_429_503(Config.TEST_BUCKET.create)()
+    # mTLS testing uses the system test as well. For mTLS testing,
+    # GOOGLE_API_USE_CLIENT_CERTIFICATE env var will be set to "true"
+    # explicitly.
+    Config.TESTING_MTLS = os.getenv("GOOGLE_API_USE_CLIENT_CERTIFICATE") == "true"
 
 
 def tearDownModule():
@@ -101,6 +106,15 @@ def tearDownModule():
 
 
 class TestClient(unittest.TestCase):
+    @classmethod
+    def setUpClass(cls):
+        super(TestClient, cls).setUpClass()
+        if (
+            type(Config.CLIENT._credentials)
+            is not google.oauth2.service_account.Credentials
+        ):
+            raise unittest.SkipTest("These tests require a service account credential")
+
     def setUp(self):
         self.case_hmac_keys_to_delete = []
 
@@ -563,6 +577,15 @@ def tearDown(self):
 class TestStorageWriteFiles(TestStorageFiles):
     ENCRYPTION_KEY = "b23ff11bba187db8c37077e6af3b25b8"
 
+    @classmethod
+    def setUpClass(cls):
+        super(TestStorageWriteFiles, cls).setUpClass()
+        if (
+            type(Config.CLIENT._credentials)
+            is not google.oauth2.service_account.Credentials
+        ):
+            raise unittest.SkipTest("These tests require a service account credential")
+
     def test_large_file_write_from_stream(self):
         blob = self.bucket.blob("LargeFile")
 
@@ -1285,11 +1308,14 @@ class TestStorageSignURLs(unittest.TestCase):
 
     @classmethod
     def setUpClass(cls):
+        super(TestStorageSignURLs, cls).setUpClass()
         if (
             type(Config.CLIENT._credentials)
             is not google.oauth2.service_account.Credentials
         ):
-            cls.skipTest("Signing tests requires a service account credential")
+            raise unittest.SkipTest(
+                "Signing tests requires a service account credential"
+            )
 
         bucket_name = "gcp-signing" + unique_resource_id()
         cls.bucket = retry_429_503(Config.CLIENT.create_bucket)(bucket_name)
@@ -1850,6 +1876,18 @@ class TestStorageNotificationCRUD(unittest.TestCase):
     CUSTOM_ATTRIBUTES = {"attr1": "value1", "attr2": "value2"}
     BLOB_NAME_PREFIX = "blob-name-prefix/"
 
+    @classmethod
+    def setUpClass(cls):
+        super(TestStorageNotificationCRUD, cls).setUpClass()
+        if Config.TESTING_MTLS:
+            # mTLS is only available for python-pubsub >= 2.2.0. However, the
+            # system test uses python-pubsub < 2.0, so we skip those tests.
+            # Note that python-pubsub >= 2.0 no longer supports python 2.7, so
+            # we can only upgrade it after python 2.7 system test is removed.
+            # Since python-pubsub >= 2.0 has a new set of api, the test code
+            # also needs to be updated.
+            raise unittest.SkipTest("Skip pubsub tests for mTLS testing")
+
     @property
     def topic_path(self):
         return "projects/{}/topics/{}".format(Config.CLIENT.project, self.TOPIC_NAME)
@@ -2013,6 +2051,15 @@ def _kms_key_name(self, key_name=None):
     @classmethod
     def setUpClass(cls):
         super(TestKMSIntegration, cls).setUpClass()
+        if Config.TESTING_MTLS:
+            # mTLS is only available for python-kms >= 2.2.0. However, the
+            # system test uses python-kms < 2.0, so we skip those tests.
+            # Note that python-kms >= 2.0 no longer supports python 2.7, so
+            # we can only upgrade it after python 2.7 system test is removed.
+            # Since python-kms >= 2.0 has a new set of api, the test code
+            # also needs to be updated.
+            raise unittest.SkipTest("Skip kms tests for mTLS testing")
+
         _empty_bucket(Config.CLIENT, cls.bucket)
 
     def setUp(self):
@@ -2466,6 +2513,17 @@ def test_ubla_set_unset_preserves_acls(self):
 
 
 class TestV4POSTPolicies(unittest.TestCase):
+    @classmethod
+    def setUpClass(cls):
+        super(TestV4POSTPolicies, cls).setUpClass()
+        if (
+            type(Config.CLIENT._credentials)
+            is not google.oauth2.service_account.Credentials
+        ):
+            # mTLS only works for user credentials, it doesn't work for
+            # service account credentials.
+            raise unittest.SkipTest("These tests require a service account credential")
+
     def setUp(self):
         self.case_buckets_to_delete = []
 

tests/unit/test__http.py

@@ -25,6 +25,8 @@ def _get_target_class():
         return Connection
 
     def _make_one(self, *args, **kw):
+        if "api_endpoint" not in kw:
+            kw["api_endpoint"] = "https://storage.googleapis.com"
         return self._get_target_class()(*args, **kw)
 
     def test_extra_headers(self):
@@ -213,3 +215,16 @@ def test_api_request_conditional_retry_failed(self):
             retry=conditional_retry_mock,
         )
         http.request.assert_called_once()
+
+    def test_mtls(self):
+        client = object()
+
+        conn = self._make_one(client, api_endpoint=None)
+        self.assertEqual(conn.ALLOW_AUTO_SWITCH_TO_MTLS_URL, True)
+        self.assertEqual(conn.API_BASE_URL, "https://storage.googleapis.com")
+        self.assertEqual(conn.API_BASE_MTLS_URL, "https://storage.mtls.googleapis.com")
+
+        conn = self._make_one(client, api_endpoint="http://foo")
+        self.assertEqual(conn.ALLOW_AUTO_SWITCH_TO_MTLS_URL, False)
+        self.assertEqual(conn.API_BASE_URL, "http://foo")
+        self.assertEqual(conn.API_BASE_MTLS_URL, "https://storage.mtls.googleapis.com")