Don't fail /submit_token requests on incorrect session ID if request_token_inhibit_3pid_errors is turned on (#7991)

* Don't raise session_id errors on submit_token if request_token_inhibit_3pid_errors is set

* Changelog

* Also wait some time before responding to /requestToken

* Incorporate review

* Update synapse/storage/databases/main/registration.py

Co-authored-by: Andrew Morgan <1342360+anoadragon453@users.noreply.github.com>

* Incorporate review

Co-authored-by: Andrew Morgan <1342360+anoadragon453@users.noreply.github.com>

2 files changed, 17 insertions, 0 deletions

diff --git a/synapse/rest/client/v2_alpha/account.py b/synapse/rest/client/v2_alpha/account.py
index 203e76b9f2..3481477731 100644
--- a/synapse/rest/client/v2_alpha/account.py
+++ b/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
@@ -109,6 +110,9 @@ class EmailPasswordRequestTokenRestServlet(RestServlet):
             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)
@@ -448,6 +452,9 @@ class EmailThreepidRequestTokenRestServlet(RestServlet):
             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)
@@ -516,6 +523,9 @@ class MsisdnThreepidRequestTokenRestServlet(RestServlet):
             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)
diff --git a/synapse/rest/client/v2_alpha/register.py b/synapse/rest/client/v2_alpha/register.py
index be0e680ac5..51372cdb5e 100644
--- a/synapse/rest/client/v2_alpha/register.py
+++ b/synapse/rest/client/v2_alpha/register.py
@@ -16,6 +16,7 @@
 
 import hmac
 import logging
+import random
 from typing import List, Union
 
 import synapse
@@ -131,6 +132,9 @@ class EmailRegisterRequestTokenRestServlet(RestServlet):
             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)
@@ -203,6 +207,9 @@ class MsisdnRegisterRequestTokenRestServlet(RestServlet):
             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(