==========================
Security update
---------------
This release includes *four* security fixes:
- Prevent an attack where a federated server could send redactions for arbitrary events in v1 and v2 rooms. ([\#5767](https://github.com/matrix-org/synapse/issues/5767))
- Prevent a denial-of-service attack where cycles of redaction events would make Synapse spin infinitely. Thanks to `@lrizika:matrix.org` for identifying and responsibly disclosing this issue. ([0f2ecb961](https://github.com/matrix-org/synapse/commit/0f2ecb961))
- Prevent an attack where users could be joined or parted from public rooms without their consent. Thanks to @Dylanger for identifying and responsibly disclosing this issue. ([\#5744](https://github.com/matrix-org/synapse/issues/5744))
- Fix a vulnerability where a federated server could spoof read-receipts from
users on other servers. Thanks to @Dylanger for identifying this issue too. ([\#5743](https://github.com/matrix-org/synapse/issues/5743))
Additionally, the following fix was in Synapse **1.2.0**, but was not correctly
identified during the original release:
- It was possible for a room moderator to send a redaction for an `m.room.create` event, which would downgrade the room to version 1. Thanks to `/dev/ponies` for identifying and responsibly disclosing this issue! ([\#5701](https://github.com/matrix-org/synapse/issues/5701))
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Merge tag 'v1.2.1' into shhs
Synapse 1.2.1 (2019-07-26)
==========================
Security update
---------------
This release includes *four* security fixes:
- Prevent an attack where a federated server could send redactions for arbitrary events in v1 and v2 rooms. ([\#5767](https://github.com/matrix-org/synapse/issues/5767))
- Prevent a denial-of-service attack where cycles of redaction events would make Synapse spin infinitely. Thanks to `@lrizika:matrix.org` for identifying and responsibly disclosing this issue. ([0f2ecb961](https://github.com/matrix-org/synapse/commit/0f2ecb961))
- Prevent an attack where users could be joined or parted from public rooms without their consent. Thanks to @Dylanger for identifying and responsibly disclosing this issue. ([\#5744](https://github.com/matrix-org/synapse/issues/5744))
- Fix a vulnerability where a federated server could spoof read-receipts from
users on other servers. Thanks to @Dylanger for identifying this issue too. ([\#5743](https://github.com/matrix-org/synapse/issues/5743))
Additionally, the following fix was in Synapse **1.2.0**, but was not correctly
identified during the original release:
- It was possible for a room moderator to send a redaction for an `m.room.create` event, which would downgrade the room to version 1. Thanks to `/dev/ponies` for identifying and responsibly disclosing this issue! ([\#5701](https://github.com/matrix-org/synapse/issues/5701))
* Fix servlet metric names
Co-Authored-By: Richard van der Hoff <1389908+richvdh@users.noreply.github.com>
* Remove redundant check
* Cover all return paths
* Opentracing survival guide
* Update decorator names in doc
* Doc cleanup
These are all alterations as a result of comments in #5703, it
includes mostly typos and clarifications. The most interesting
changes are:
- Split developer and user docs into two sections
- Add a high level description of OpenTracing
* newsfile
* Move contributer specific info to docstring.
* Sample config.
* Trailing whitespace.
* Update 5703.misc
* Apply suggestions from code review
Mostly just rewording parts of the docs for clarity.
Co-Authored-By: Richard van der Hoff <1389908+richvdh@users.noreply.github.com>
Clean up config settings and dead code.
This is mostly about cleaning up the config format, to bring it into line with our conventions. In particular:
* There should be a blank line after `## Section ##' headings
* There should be a blank line between each config setting
* There should be a `#`-only line between a comment and the setting it describes
* We don't really do the `# #` style commenting-out of whole sections if we can help it
* rename `tracer_enabled` to `enabled`
While we're here, do more config parsing upfront, which makes it easier to use
later on.
Also removes redundant code from LogContextScopeManager.
Also changes the changelog fragment to a `feature` - it's exciting!
* Convert BaseFederationServlet._wrap to async
Empirically, this fixes some lost stacktraces. It should be safe because the
wrapped function is called from JsonResource._async_render, which is already
async.
* Convert the rest of synapse.federation.transport.server to async
We may as well do the whole file while we're here.
* changelog
* flake8
This is basically a contrived way of adding a `Recommends` on `libpq5`, to fix#5653.
The way this is supposed to happen in debhelper is to run
`dh_shlibdeps`, which in turn runs `dpkg-shlibdeps`, which spits things out
into `debian/<package>.substvars` whence they can later be included by
`control`.
Previously, we had disabled `dh_shlibdeps`, mostly because `dpkg-shlibdeps`
gets confused about PIL's interdependent objects, but that's not really the
right thing to do and there is another way to work around that.
Since we don't always use postgres, we don't necessarily want a hard Depends on
libpq5, so I've actually ended up adding an explicit invocation of
`dpkg-shlibdeps` for `psycopg2`.
I've also updated the build-depends list for the package, which was missing a
couple of entries.
We can now use `_get_events_from_cache_or_db` rather than going right back to
the database, which means that (a) we can benefit from caching, and (b) it
opens the way forward to more extensive checks on the original event.
We now always require the original event to exist before we will serve up a
redaction.
Ensures that redactions are correctly authenticated for recent room versions.
There are a few things going on here:
* `_fetch_event_rows` is updated to return a dict rather than a list of rows.
* Rather than returning multiple copies of an event which was redacted
multiple times, it returns the redactions as a list within the dict.
* It also returns the actual rejection reason, rather than merely the fact
that it was rejected, so that we don't have to query the table again in
`_get_event_from_row`.
* The redaction handling is factored out of `_get_event_from_row`, and now
checks if any of the redactions are valid.
A couple of changes here:
* get rid of a redundant `allow_rejected` condition - we should already have filtered out any rejected
events before we get to that point in the code, and the redundancy is confusing. Instead, let's stick in
an assertion just to make double-sure we aren't leaking rejected events by mistake.
* factor out a `_get_events_from_cache_or_db` method, which is going to be important for a
forthcoming fix to redactions.
