Don't fail /submit_token requests on incorrect session ID if request_token_inhibit_3pid_errors is turned on

changelog.d/7991.misc

@@ -0,0 +1 @@
+Don't fail `/submit_token` requests on incorrect session ID if `request_token_inhibit_3pid_errors` is turned on.

synapse/rest/client/v2_alpha/account.py

@@ -15,6 +15,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 import logging
+import random
 from http import HTTPStatus
 
 from synapse.api.constants import LoginType
@@ -114,6 +115,9 @@ async def on_POST(self, request):
             if self.config.request_token_inhibit_3pid_errors:
                 # Make the client think the operation succeeded. See the rationale in the
                 # comments for request_token_inhibit_3pid_errors.
+                # Also wait for some random amount of time between 100ms and 1s to make it
+                # look like we did something.
+                await self.hs.clock.sleep(random.randint(1, 10) / 10)
                 return 200, {"sid": random_string(16)}
 
             raise SynapseError(400, "Email not found", Codes.THREEPID_NOT_FOUND)
@@ -433,6 +437,9 @@ async def on_POST(self, request):
             if self.config.request_token_inhibit_3pid_errors:
                 # Make the client think the operation succeeded. See the rationale in the
                 # comments for request_token_inhibit_3pid_errors.
+                # Also wait for some random amount of time between 100ms and 1s to make it
+                # look like we did something.
+                await self.hs.clock.sleep(random.randint(1, 10) / 10)
                 return 200, {"sid": random_string(16)}
 
             raise SynapseError(400, "Email is already in use", Codes.THREEPID_IN_USE)
@@ -501,6 +508,9 @@ async def on_POST(self, request):
             if self.hs.config.request_token_inhibit_3pid_errors:
                 # Make the client think the operation succeeded. See the rationale in the
                 # comments for request_token_inhibit_3pid_errors.
+                # Also wait for some random amount of time between 100ms and 1s to make it
+                # look like we did something.
+                await self.hs.clock.sleep(random.randint(1, 10) / 10)
                 return 200, {"sid": random_string(16)}
 
             raise SynapseError(400, "MSISDN is already in use", Codes.THREEPID_IN_USE)

synapse/rest/client/v2_alpha/register.py

@@ -16,6 +16,7 @@
 
 import hmac
 import logging
+import random
 from typing import List, Union
 
 import synapse
@@ -142,6 +143,9 @@ async def on_POST(self, request):
             if self.hs.config.request_token_inhibit_3pid_errors:
                 # Make the client think the operation succeeded. See the rationale in the
                 # comments for request_token_inhibit_3pid_errors.
+                # Also wait for some random amount of time between 100ms and 1s to make it
+                # look like we did something.
+                await self.hs.clock.sleep(random.randint(1, 10) / 10)
                 return 200, {"sid": random_string(16)}
 
             raise SynapseError(400, "Email is already in use", Codes.THREEPID_IN_USE)
@@ -214,6 +218,9 @@ async def on_POST(self, request):
             if self.hs.config.request_token_inhibit_3pid_errors:
                 # Make the client think the operation succeeded. See the rationale in the
                 # comments for request_token_inhibit_3pid_errors.
+                # Also wait for some random amount of time between 100ms and 1s to make it
+                # look like we did something.
+                await self.hs.clock.sleep(random.randint(1, 10) / 10)
                 return 200, {"sid": random_string(16)}
 
             raise SynapseError(

synapse/storage/data_stores/main/registration.py

@@ -911,6 +911,7 @@ def __init__(self, database: Database, db_conn, hs):
         super(RegistrationStore, self).__init__(database, db_conn, hs)
 
         self._account_validity = hs.config.account_validity
+        self._ignore_unknown_session_error = hs.config.request_token_inhibit_3pid_errors
 
         if self._account_validity.enabled:
             self._clock.call_later(
@@ -1315,15 +1316,14 @@ def validate_threepid_session_txn(txn):
             )
 
             if not row:
-                raise ThreepidValidationError(400, "Unknown session_id")
+                if self._ignore_unknown_session_error:
+                    row = {"client_secret": None, "validated_at": None}
+                else:
+                    raise ThreepidValidationError(400, "Unknown session_id")
+
             retrieved_client_secret = row["client_secret"]
             validated_at = row["validated_at"]
 
-            if retrieved_client_secret != client_secret:
-                raise ThreepidValidationError(
-                    400, "This client_secret does not match the provided session_id"
-                )
-
             row = self.db.simple_select_one_txn(
                 txn,
                 table="threepid_validation_token",
@@ -1339,6 +1339,11 @@ def validate_threepid_session_txn(txn):
             expires = row["expires"]
             next_link = row["next_link"]
 
+            if retrieved_client_secret != client_secret:
+                raise ThreepidValidationError(
+                    400, "This client_secret does not match the provided session_id"
+                )
+
             # If the session is already validated, no need to revalidate
             if validated_at:
                 return next_link