Do not use canonicaljson to magically handle decoding bytes from JSON. (#7802)

7 files changed, 17 insertions, 28 deletions

diff --git a/changelog.d/7802.misc b/changelog.d/7802.misc
new file mode 100644
index 0000000000..d81f8875c5
--- /dev/null
+++ b/changelog.d/7802.misc
@@ -0,0 +1 @@
+ Switch from simplejson to the standard library json.
diff --git a/synapse/api/errors.py b/synapse/api/errors.py
index 5305038c21..d5d4522336 100644
--- a/synapse/api/errors.py
+++ b/synapse/api/errors.py
@@ -15,13 +15,11 @@
 # limitations under the License.
 
 """Contains exceptions and error codes."""
-
+import json
 import logging
 from http import HTTPStatus
 from typing import Dict, List
 
-from canonicaljson import json
-
 from twisted.web import http
 
 logger = logging.getLogger(__name__)
@@ -573,7 +571,7 @@ class HttpResponseException(CodeMessageException):
         # try to parse the body as json, to get better errcode/msg, but
         # default to M_UNKNOWN with the HTTP status as the error text
         try:
-            j = json.loads(self.response)
+            j = json.loads(self.response.decode("utf-8"))
         except ValueError:
             j = {}
 
diff --git a/synapse/federation/federation_server.py b/synapse/federation/federation_server.py
index 86051decd4..2aab9c5f55 100644
--- a/synapse/federation/federation_server.py
+++ b/synapse/federation/federation_server.py
@@ -14,10 +14,10 @@
 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 # See the License for the specific language governing permissions and
 # limitations under the License.
+import json
 import logging
 from typing import Any, Callable, Dict, List, Match, Optional, Tuple, Union
 
-from canonicaljson import json
 from prometheus_client import Counter, Histogram
 
 from twisted.internet import defer
@@ -526,9 +526,9 @@ class FederationServer(FederationBase):
         json_result = {}  # type: Dict[str, Dict[str, dict]]
         for user_id, device_keys in results.items():
             for device_id, keys in device_keys.items():
-                for key_id, json_bytes in keys.items():
+                for key_id, json_str in keys.items():
                     json_result.setdefault(user_id, {})[device_id] = {
-                        key_id: json.loads(json_bytes)
+                        key_id: json.loads(json_str)
                     }
 
         logger.info(
diff --git a/synapse/handlers/cas_handler.py b/synapse/handlers/cas_handler.py
index d79ffefdb5..786e608fa2 100644
--- a/synapse/handlers/cas_handler.py
+++ b/synapse/handlers/cas_handler.py
@@ -104,7 +104,7 @@ class CasHandler:
         return user, displayname
 
     def _parse_cas_response(
-        self, cas_response_body: str
+        self, cas_response_body: bytes
     ) -> Tuple[str, Dict[str, Optional[str]]]:
         """
         Retrieve the user and other parameters from the CAS response.
diff --git a/synapse/http/client.py b/synapse/http/client.py
index 8743e9839d..505872ee90 100644
--- a/synapse/http/client.py
+++ b/synapse/http/client.py
@@ -13,13 +13,13 @@
 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 # See the License for the specific language governing permissions and
 # limitations under the License.
-
+import json
 import logging
 import urllib
 from io import BytesIO
 
 import treq
-from canonicaljson import encode_canonical_json, json
+from canonicaljson import encode_canonical_json
 from netaddr import IPAddress
 from prometheus_client import Counter
 from zope.interface import implementer, provider
@@ -371,7 +371,7 @@ class SimpleHttpClient(object):
         body = yield make_deferred_yieldable(readBody(response))
 
         if 200 <= response.code < 300:
-            return json.loads(body)
+            return json.loads(body.decode("utf-8"))
         else:
             raise HttpResponseException(response.code, response.phrase, body)
 
@@ -412,7 +412,7 @@ class SimpleHttpClient(object):
         body = yield make_deferred_yieldable(readBody(response))
 
         if 200 <= response.code < 300:
-            return json.loads(body)
+            return json.loads(body.decode("utf-8"))
         else:
             raise HttpResponseException(response.code, response.phrase, body)
 
@@ -441,7 +441,7 @@ class SimpleHttpClient(object):
             actual_headers.update(headers)
 
         body = yield self.get_raw(uri, args, headers=headers)
-        return json.loads(body)
+        return json.loads(body.decode("utf-8"))
 
     @defer.inlineCallbacks
     def put_json(self, uri, json_body, args={}, headers=None):
@@ -485,7 +485,7 @@ class SimpleHttpClient(object):
         body = yield make_deferred_yieldable(readBody(response))
 
         if 200 <= response.code < 300:
-            return json.loads(body)
+            return json.loads(body.decode("utf-8"))
         else:
             raise HttpResponseException(response.code, response.phrase, body)
 
@@ -503,7 +503,7 @@ class SimpleHttpClient(object):
                header name to a list of values for that header
         Returns:
             Deferred: Succeeds when we get *any* 2xx HTTP response, with the
-            HTTP body at text.
+            HTTP body as bytes.
         Raises:
             HttpResponseException on a non-2xx HTTP response.
         """
diff --git a/synapse/http/servlet.py b/synapse/http/servlet.py
index 13fcb408a6..3cabe9d02e 100644
--- a/synapse/http/servlet.py
+++ b/synapse/http/servlet.py
@@ -14,11 +14,9 @@
 # limitations under the License.
 
 """ This module contains base REST classes for constructing REST servlets. """
-
+import json
 import logging
 
-from canonicaljson import json
-
 from synapse.api.errors import Codes, SynapseError
 
 logger = logging.getLogger(__name__)
@@ -214,16 +212,8 @@ def parse_json_value_from_request(request, allow_empty_body=False):
     if not content_bytes and allow_empty_body:
         return None
 
-    # Decode to Unicode so that simplejson will return Unicode strings on
-    # Python 2
-    try:
-        content_unicode = content_bytes.decode("utf8")
-    except UnicodeDecodeError:
-        logger.warning("Unable to decode UTF-8")
-        raise SynapseError(400, "Content not JSON.", errcode=Codes.NOT_JSON)
-
     try:
-        content = json.loads(content_unicode)
+        content = json.loads(content_bytes.decode("utf-8"))
     except Exception as e:
         logger.warning("Unable to parse JSON: %s", e)
         raise SynapseError(400, "Content not JSON.", errcode=Codes.NOT_JSON)
diff --git a/tests/rest/client/v1/test_login.py b/tests/rest/client/v1/test_login.py
index fd97999956..2be7238b00 100644
--- a/tests/rest/client/v1/test_login.py
+++ b/tests/rest/client/v1/test_login.py
@@ -398,7 +398,7 @@ class CASTestCase(unittest.HomeserverTestCase):
                 </cas:serviceResponse>
             """
                 % cas_user_id
-            )
+            ).encode("utf-8")
 
         mocked_http_client = Mock(spec=["get_raw"])
         mocked_http_client.get_raw.side_effect = get_raw