- Synapse's cipher string has been updated to require ECDH key exchange. Configuring and generating dh_params is no longer required, and they will be ignored. ([\#4229](https://github.com/matrix-org/synapse/issues/4229))
- Synapse can now automatically provision TLS certificates via ACME (the protocol used by CAs like Let's Encrypt). ([\#4384](https://github.com/matrix-org/synapse/issues/4384), [\#4492](https://github.com/matrix-org/synapse/issues/4492), [\#4525](https://github.com/matrix-org/synapse/issues/4525))
- Search now includes results from predecessor rooms after a room upgrade. ([\#4415](https://github.com/matrix-org/synapse/issues/4415))
- Config option to disable requesting MSISDN on registration. ([\#4423](https://github.com/matrix-org/synapse/issues/4423))
- Add a metric for tracking event stream position of the user directory. ([\#4445](https://github.com/matrix-org/synapse/issues/4445))
- Support exposing server capabilities in CS API (MSC1753, MSC1804) ([\#4472](https://github.com/matrix-org/synapse/issues/4472))
- Add support for room version 3 ([\#4483](https://github.com/matrix-org/synapse/issues/4483), [\#4499](https://github.com/matrix-org/synapse/issues/4499), [\#4515](https://github.com/matrix-org/synapse/issues/4515), [\#4523](https://github.com/matrix-org/synapse/issues/4523))
- Synapse will now reload TLS certificates from disk upon SIGHUP. ([\#4495](https://github.com/matrix-org/synapse/issues/4495), [\#4524](https://github.com/matrix-org/synapse/issues/4524))
Bugfixes
--------
- Prevent users with access tokens predating the introduction of device IDs from creating spurious entries in the user_ips table. ([\#4369](https://github.com/matrix-org/synapse/issues/4369))
- Fix typo in ALL_USER_TYPES definition to ensure type is a tuple ([\#4392](https://github.com/matrix-org/synapse/issues/4392))
- Fix high CPU usage due to remote devicelist updates ([\#4397](https://github.com/matrix-org/synapse/issues/4397))
- Fix potential bug where creating or joining a room could fail ([\#4404](https://github.com/matrix-org/synapse/issues/4404))
- Fix bug when rejecting remote invites ([\#4405](https://github.com/matrix-org/synapse/issues/4405))
- Fix incorrect logcontexts after a Deferred was cancelled ([\#4407](https://github.com/matrix-org/synapse/issues/4407))
- Ensure encrypted room state is persisted across room upgrades. ([\#4411](https://github.com/matrix-org/synapse/issues/4411))
- Copy over whether a room is a direct message and any associated room tags on room upgrade. ([\#4412](https://github.com/matrix-org/synapse/issues/4412))
- Fix None guard in calling config.server.is_threepid_reserved ([\#4435](https://github.com/matrix-org/synapse/issues/4435))
- Don't send IP addresses as SNI ([\#4452](https://github.com/matrix-org/synapse/issues/4452))
- Fix UnboundLocalError in post_urlencoded_get_json ([\#4460](https://github.com/matrix-org/synapse/issues/4460))
- Add a timeout to filtered room directory queries. ([\#4461](https://github.com/matrix-org/synapse/issues/4461))
- Workaround for login error when using both LDAP and internal authentication. ([\#4486](https://github.com/matrix-org/synapse/issues/4486))
- Fix a bug where setting a relative consent directory path would cause a crash. ([\#4512](https://github.com/matrix-org/synapse/issues/4512))
Deprecations and Removals
-------------------------
- Synapse no longer generates self-signed TLS certificates when generating a configuration file. ([\#4509](https://github.com/matrix-org/synapse/issues/4509))
Internal Changes
----------------
- Synapse will now take advantage of native UPSERT functionality in PostgreSQL 9.5+ and SQLite 3.24+. ([\#4306](https://github.com/matrix-org/synapse/issues/4306), [\#4459](https://github.com/matrix-org/synapse/issues/4459), [\#4466](https://github.com/matrix-org/synapse/issues/4466), [\#4471](https://github.com/matrix-org/synapse/issues/4471), [\#4477](https://github.com/matrix-org/synapse/issues/4477), [\#4505](https://github.com/matrix-org/synapse/issues/4505))
- Update README to use the new virtualenv everywhere ([\#4342](https://github.com/matrix-org/synapse/issues/4342))
- Add better logging for unexpected errors while sending transactions ([\#4368](https://github.com/matrix-org/synapse/issues/4368))
- Apply a unique index to the user_ips table, preventing duplicates. ([\#4370](https://github.com/matrix-org/synapse/issues/4370), [\#4432](https://github.com/matrix-org/synapse/issues/4432), [\#4434](https://github.com/matrix-org/synapse/issues/4434))
- Silence travis-ci build warnings by removing non-functional python3.6 ([\#4377](https://github.com/matrix-org/synapse/issues/4377))
- Fix a comment in the generated config file ([\#4387](https://github.com/matrix-org/synapse/issues/4387))
- Add ground work for implementing future federation API versions ([\#4390](https://github.com/matrix-org/synapse/issues/4390))
- Update dependencies on msgpack and pymacaroons to use the up-to-date packages. ([\#4399](https://github.com/matrix-org/synapse/issues/4399))
- Tweak codecov settings to make them less loud. ([\#4400](https://github.com/matrix-org/synapse/issues/4400))
- Implement server support for MSC1794 - Federation v2 Invite API ([\#4402](https://github.com/matrix-org/synapse/issues/4402))
- debian package: symlink to explicit python version ([\#4433](https://github.com/matrix-org/synapse/issues/4433))
- Add infrastructure to support different event formats ([\#4437](https://github.com/matrix-org/synapse/issues/4437), [\#4447](https://github.com/matrix-org/synapse/issues/4447), [\#4448](https://github.com/matrix-org/synapse/issues/4448), [\#4470](https://github.com/matrix-org/synapse/issues/4470), [\#4481](https://github.com/matrix-org/synapse/issues/4481), [\#4482](https://github.com/matrix-org/synapse/issues/4482), [\#4493](https://github.com/matrix-org/synapse/issues/4493), [\#4494](https://github.com/matrix-org/synapse/issues/4494), [\#4496](https://github.com/matrix-org/synapse/issues/4496), [\#4510](https://github.com/matrix-org/synapse/issues/4510), [\#4514](https://github.com/matrix-org/synapse/issues/4514))
- Generate the debian config during build ([\#4444](https://github.com/matrix-org/synapse/issues/4444))
- Clarify documentation for the `public_baseurl` config param ([\#4458](https://github.com/matrix-org/synapse/issues/4458), [\#4498](https://github.com/matrix-org/synapse/issues/4498))
- Fix quoting for allowed_local_3pids example config ([\#4476](https://github.com/matrix-org/synapse/issues/4476))
- Remove deprecated --process-dependency-links option from UPGRADE.rst ([\#4485](https://github.com/matrix-org/synapse/issues/4485))
- Make it possible to set the log level for tests via an environment variable ([\#4506](https://github.com/matrix-org/synapse/issues/4506))
- Reduce the log level of linearizer lock acquirement to DEBUG. ([\#4507](https://github.com/matrix-org/synapse/issues/4507))
- Fix code to comply with linting in PyFlakes 3.7.1. ([\#4519](https://github.com/matrix-org/synapse/issues/4519))
Richard van der Hoff
6 years ago