feat(storage): improve v4 signature query parameters encoding (#48)

* feat(storage): improve v4 signature query parameters encoding

* add URL encoding test

* add query_parameters arg into conformance tests

* add tests for _quote_param() function

* declare test file encoding

* fix the param type

* add test with bytes

* Update _signing.py

Co-authored-by: Frank Natividad <frankyn@users.noreply.github.com>
Co-authored-by: Christopher Wilcox <crwilcox@google.com>

google/cloud/storage/_signing.py

@@ -509,7 +509,7 @@ def generate_signed_url_v4(
 
     :type query_parameters: dict
     :param query_parameters:
-        (Optional) Additional query paramtersto be included as part of the
+        (Optional) Additional query parameters to be included as part of the
         signed URLs.  See:
         https://cloud.google.com/storage/docs/xml-api/reference-headers#query
 
@@ -585,8 +585,7 @@ def generate_signed_url_v4(
     if generation is not None:
         query_parameters["generation"] = generation
 
-    ordered_query_parameters = sorted(query_parameters.items())
-    canonical_query_string = six.moves.urllib.parse.urlencode(ordered_query_parameters)
+    canonical_query_string = _url_encode(query_parameters)
 
     lowercased_headers = dict(ordered_headers)
 
@@ -672,3 +671,34 @@ def _sign_message(message, access_token, service_account_email):
 
     data = json.loads(response.data.decode("utf-8"))
     return data["signature"]
+
+
+def _url_encode(query_params):
+    """Encode query params into URL.
+
+    :type query_params: dict
+    :param query_params: Query params to be encoded.
+
+    :rtype: str
+    :returns: URL encoded query params.
+    """
+    params = [
+        "{}={}".format(_quote_param(name), _quote_param(value))
+        for name, value in query_params.items()
+    ]
+
+    return "&".join(sorted(params))
+
+
+def _quote_param(param):
+    """Quote query param.
+
+    :type param: Any
+    :param param: Query param to be encoded.
+
+    :rtype: str
+    :returns: URL encoded query param.
+    """
+    if not isinstance(param, bytes):
+        param = str(param)
+    return six.moves.urllib.parse.quote(param, safe="~")

tests/unit/test__signing.py

@@ -1,3 +1,5 @@
+# -*- coding: utf-8 -*-
+#
 # Copyright 2017 Google LLC
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
@@ -705,6 +707,61 @@ def test_sign_bytes_failure(self):
                 )
 
 
+class TestCustomURLEncoding(unittest.TestCase):
+    def test_url_encode(self):
+        from google.cloud.storage._signing import _url_encode
+
+        # param1 includes safe symbol ~
+        # param# includes symbols, which must be encoded
+        query_params = {"param1": "value~1-2", "param#": "*value+value/"}
+
+        self.assertEqual(
+            _url_encode(query_params), "param%23=%2Avalue%2Bvalue%2F&param1=value~1-2"
+        )
+
+
+class TestQuoteParam(unittest.TestCase):
+    def test_ascii_symbols(self):
+        from google.cloud.storage._signing import _quote_param
+
+        encoded_param = _quote_param("param")
+        self.assertIsInstance(encoded_param, str)
+        self.assertEqual(encoded_param, "param")
+
+    def test_quoted_symbols(self):
+        from google.cloud.storage._signing import _quote_param
+
+        encoded_param = _quote_param("!#$%&'()*+,/:;=?@[]")
+        self.assertIsInstance(encoded_param, str)
+        self.assertEqual(
+            encoded_param, "%21%23%24%25%26%27%28%29%2A%2B%2C%2F%3A%3B%3D%3F%40%5B%5D"
+        )
+
+    def test_unquoted_symbols(self):
+        from google.cloud.storage._signing import _quote_param
+        import string
+
+        UNQUOTED = string.ascii_letters + string.digits + ".~_-"
+
+        encoded_param = _quote_param(UNQUOTED)
+        self.assertIsInstance(encoded_param, str)
+        self.assertEqual(encoded_param, UNQUOTED)
+
+    def test_unicode_symbols(self):
+        from google.cloud.storage._signing import _quote_param
+
+        encoded_param = _quote_param("ЁЙЦЯЩЯЩ")
+        self.assertIsInstance(encoded_param, str)
+        self.assertEqual(encoded_param, "%D0%81%D0%99%D0%A6%D0%AF%D0%A9%D0%AF%D0%A9")
+
+    def test_bytes(self):
+        from google.cloud.storage._signing import _quote_param
+
+        encoded_param = _quote_param(b"bytes")
+        self.assertIsInstance(encoded_param, str)
+        self.assertEqual(encoded_param, "bytes")
+
+
 _DUMMY_SERVICE_ACCOUNT = None
 
 
@@ -731,6 +788,7 @@ def _run_conformance_test(resource, test_data):
         method=test_data["method"],
         _request_timestamp=test_data["timestamp"],
         headers=test_data.get("headers"),
+        query_parameters=test_data.get("queryParameters"),
     )
 
     assert url == test_data["expectedUrl"]