Fixes#15871
### What was broken
Sending `{"auth": null}` to any endpoint that requires user-interactive
auth (for example `POST /keys/device_signing/upload`, `DELETE
/devices/{deviceId}` or `POST /register`) returned a 500 instead of the
usual 401 with the available flows. A non-object `auth` on endpoints
that do not validate the body with a model (such as `/register`) could
also 500, e.g. `{"auth": ["session"]}`.
### Root cause
`AuthHandler.check_ui_auth` did `clientdict.pop("auth", {})`, so the
`{}` default only applies when the key is missing. An explicit `null`
came through as `None` and the following `"session" in authdict` raised
`TypeError`. `get_session_id` had the same assumption that `auth` is a
dict.
### Pull Request Checklist
* [x] Pull request is based on the develop branch
* [x] Pull request includes a [changelog
file](https://element-hq.github.io/synapse/latest/development/contributing_guide.html#changelog).
* [x] [Code
style](https://element-hq.github.io/synapse/latest/code_style.html) is
correct (run the
[linters](https://element-hq.github.io/synapse/latest/development/contributing_guide.html#run-the-linters))
---------
Signed-off-by: Ankit Jha <ankit.jha@tradomate.one>
The spec says `device_keys` may be omitted, but not set to `null`.
This was temporarily allowed as a workaround for misbehaving clients
(see #19023), which have since been fixed.
Fixes#19030
During the migration the automated script to update the copyright
headers accidentally got rid of some of the existing copyright lines.
Reinstate them.
* Describe `insert_client_ip`
* Pull out client_ips and MAU tracking to BaseAuth
* Define HAS_AUTHLIB once in tests
sick of copypasting
* Track ips and token usage when delegating auth
* Test that we track MAU and user_ips
* Don't track `__oidc_admin`
Ankit Jha