This commit adds two config options:
* `restrict_public_rooms_to_local_users`
Requires auth to fetch the public rooms directory through the CS API and disables fetching it through the federation API.
* `require_auth_for_profile_requests`
When set to `true`, requires that requests to `/profile` over the CS API are authenticated, and only returns the user's profile if the requester shares a room with the profile's owner, as per MSC1301.
MSC1301 also specifies a behaviour for federation (only returning the profile if the server asking for it shares a room with the profile's owner), but that's currently really non-trivial to do in a not too expensive way. Next step is writing down a MSC that allows a HS to specify which user sent the profile query. In this implementation, Synapse won't send a profile query over federation if it doesn't believe it already shares a room with the profile's owner, though.
Groups have been intentionally omitted from this commit.
Make it so that most options in the config are optional, and commented out in
the generated config.
The reasons this is a good thing are as follows:
* If we decide that we should change the default for an option, we can do so,
and only those admins that have deliberately chosen to override that option
will be stuck on the old setting.
* It moves us towards a point where we can get rid of the super-surprising
feature of synapse where the default settings for the config come from the
generated yaml.
* It makes setting up a test config for unit testing an order of magnitude
easier (see forthcoming PR).
* It makes the generated config more consistent, and hopefully easier for users
to understand.
* Rate-limiting for registration
* Add unit test for registration rate limiting
* Add config parameters for rate limiting on auth endpoints
* Doc
* Fix doc of rate limiting function
Co-Authored-By: babolivier <contact@brendanabolivier.com>
* Incorporate review
* Fix config parsing
* Fix linting errors
* Set default config for auth rate limiting
* Fix tests
* Add changelog
* Advance reactor instead of mocked clock
* Move parameters to registration specific config and give them more sensible default values
* Remove unused config options
* Don't mock the rate limiter un MAU tests
* Rename _register_with_store into register_with_store
* Make CI happy
* Remove unused import
* Update sample config
* Fix ratelimiting test for py2
* Add non-guest test
