arti/CHANGELOG.md

### Notes

This file describes changes in Arti through the current release.  Once Arti
is more mature, and we start to version crates independently, we will
probably switch to using a separate changelog for each crate.

# Arti 0.0.3 — 11 Jan 2022

This release adds support for preemptive circuit construction, refactors
Arti's configuration code and behavior, and adds numerous smaller features
needed for a correct Tor client implementation.

It breaks compatibility with previous releases, as is expected before
release 0.1.0 (scheduled March 2022).

### New features

- Arti now builds preemptive circuits in order to anticipate the user's
  predicted needs.  This change matches Tor's behavior more closely, and
  should reduce latency for stream creation. ([!154])
- The configuration for a [`TorClient`] object can be changed while the
  client is running. ([!181])
- Guard selection now obeys family restrictions concerning exit nodes.
  ([!139])
- Better support for overriding the [`TcpProvider`] on an Arti client and
  having this change affect the [`TlsProvider`]. This helps with testing
  support, with cases where TCP streams must be constructed specially, etc.
  ([!166])
- We no longer consider a directory to be "complete" until we have
  microdescriptors for all of our primary guards. ([!220])

### Breaking changes

- Configuration files have been reorganized, and we have an all-new API for
  creating configuration objects. ([!135], [!137])
- A few unused types and functions have been removed. ([214c251e] etc)
- `CircMgr` now returns `ClientCirc` directly, not wrapped in an `Arc`.
  (ClientCirc instances are already cheap to clone.) ([!224])
- `TorClient` now has separate `connect` and `connect_with_prefs` methods.
  ([!229])
- Various other API refactorings and revisions. (Please remember that we plan
  to break backward compatibility with _every_ release between now and 0.1.0
  in early March.)

### Major bugfixes

- We fixed a bug in handling stream-level SENDMEs that would sometimes result
  in an Arti client sending too much data, causing the exit relay to close
  the circuit. ([!194])

### Infrastructure

- We now have an experimental benchmarking tool to compare Arti's performance
  with Tor's, when running over a chutney network. So far, we seem
  competitive, but we'll probably find cases where we underperform. ([!195])
- Our coverage tool now post-processes grcov's output to produce per-crate
  results. ([!163])
- Our integration test scripts are more robust to cases where the user has
  already configured a `CHUTNEY_PATH`. ([!168])
- We have lowered the required dependency versions in our Cargo.toml files
  so that each one is the lowest version that actually works with our code.
  ([!227])

### Cleanups, minor features, and minor bugfixes

- We store fewer needless fields from Tor directory documents. ([!151],
  [!165])
- We've gone through and converted _every_ `XXXX` comment in our code (which
  indicated a must-fix issue) into a ticket, or a `TODO`. ([#231])
- Our SOCKS code is much more careful about sending error messages if
  an error occurs before the SOCKS connection succeeds. ([!189])
- We no longer build non-directory circuits when the consensus is
  super-old. ([!90])
- We no longer consider timeouts to indicate that our circuits are all timing
  out unless we have seen _some_ recent incoming network traffic. ([!207])
- You can now configure logging to files, with support for rotating the
  files hourly or daily. You can have separate filters for each logging
  target. ([!222])
- Too many others to list!

### Acknowledgments

Thanks to everybody who has contributed to this release, including dagon,
Daniel Eades, Muhammad Falak R Wani, Neel Chauhan, Trinity Pointard, and
Yuan Lyu!

[!90]: https://gitlab.torproject.org/tpo/core/arti/-/merge_requests/90
[!135]: https://gitlab.torproject.org/tpo/core/arti/-/merge_requests/135
[!137]: https://gitlab.torproject.org/tpo/core/arti/-/merge_requests/137
[!139]: https://gitlab.torproject.org/tpo/core/arti/-/merge_requests/139
[!151]: https://gitlab.torproject.org/tpo/core/arti/-/merge_requests/151
[!154]: https://gitlab.torproject.org/tpo/core/arti/-/merge_requests/154
[!163]: https://gitlab.torproject.org/tpo/core/arti/-/merge_requests/163
[!165]: https://gitlab.torproject.org/tpo/core/arti/-/merge_requests/165
[!166]: https://gitlab.torproject.org/tpo/core/arti/-/merge_requests/166
[!168]: https://gitlab.torproject.org/tpo/core/arti/-/merge_requests/168
[!181]: https://gitlab.torproject.org/tpo/core/arti/-/merge_requests/181
[!189]: https://gitlab.torproject.org/tpo/core/arti/-/merge_requests/189
[!194]: https://gitlab.torproject.org/tpo/core/arti/-/merge_requests/194
[!195]: https://gitlab.torproject.org/tpo/core/arti/-/merge_requests/195
[!207]: https://gitlab.torproject.org/tpo/core/arti/-/merge_requests/207
[!220]: https://gitlab.torproject.org/tpo/core/arti/-/merge_requests/220
[!222]: https://gitlab.torproject.org/tpo/core/arti/-/merge_requests/222
[!224]: https://gitlab.torproject.org/tpo/core/arti/-/merge_requests/224
[!227]: https://gitlab.torproject.org/tpo/core/arti/-/merge_requests/227
[!229]: https://gitlab.torproject.org/tpo/core/arti/-/merge_requests/229
[#231]: https://gitlab.torproject.org/tpo/core/arti/-/issues/231
[214c251e]: https://gitlab.torproject.org/tpo/core/arti/-/commit/214c251e41a7583397cc5939b9447b89752ee323
[`TcpProvider`]: https://tpo.pages.torproject.net/core/doc/rust/tor_rtcompat/trait.TcpProvider.html
[`TlsProvider`]: https://tpo.pages.torproject.net/core/doc/rust/tor_rtcompat/trait.TlsProvider.html
[`TorClient`]: https://tpo.pages.torproject.net/core/doc/rust/arti_client/struct.TorClient.html


# Arti 0.0.2 — 30 Nov 2021

This release tries to move us towards a more permanent API, and sets the
stage for future work in performance evaluation and event reporting.

It breaks compatibility with previous releases, as is expected before
release 0.1.0 (scheduled March 2022).

### New features

- Warn if guard restrictions are too strict. ([#242])
- Optimistic data is now supported on streams, and used by default on
  directory requests. ([#23])
- Initial cut at a typed event framework. Not yet used, but will eventually
  take the role of Tor's "controller event" system.  ([#230])
- Large rewrite of configuration handling system, with more ergonomic
  builders for top-level configurations. ([#84])


### Breaking changes

- The `${APP_*}` path variables have been renamed to
  `${ARTI_*}`. ([efdd3275])
- The configuration file format has been substantially revised. ([#84])
- Most code that clients don't need is now behind a cargo feature. ([#124])
- Revised APIs in many other high-level crates.

### Documentation

- Many other improvements and rewrites.

### Infrastructure

- Update our `cargo-husky` scripts to better match our CI. ([!62])
- Use grcov, not tarpaulin. ([!136])

### Cleanups, minor features, and bugfixes

- Huge refactoring of the `tor-proto` crate to conform more closely to the
  reactor architecture, and reduce the need for locks. ([#205], [#217]).
- By default, `cargo build --release` now chooses a more aggressive set
  of optimization flags. ([!124])
  - Too many smaller fixes to list.

### Acknowledgments

Thanks to everybody who's contributed to this release, including dagon,
Daniel Eades, Dimitris Apostolou, Neel Chauhan, S0AndS0, Trinity Pointard,
and Yuan Lyu!

[#23]: https://gitlab.torproject.org/tpo/core/arti/-/issues/23
[#84]: https://gitlab.torproject.org/tpo/core/arti/-/issues/84
[#124]: https://gitlab.torproject.org/tpo/core/arti/-/issues/124
[#205]: https://gitlab.torproject.org/tpo/core/arti/-/issues/205
[#217]: https://gitlab.torproject.org/tpo/core/arti/-/issues/217
[#230]: https://gitlab.torproject.org/tpo/core/arti/-/issues/230
[#242]: https://gitlab.torproject.org/tpo/core/arti/-/issues/242
[!62]: https://gitlab.torproject.org/tpo/core/arti/-/merge_requests/62
[!124]: https://gitlab.torproject.org/tpo/core/arti/-/merge_requests/124
[!136]: https://gitlab.torproject.org/tpo/core/arti/-/merge_requests/136
[efdd3275]: https://gitlab.torproject.org/tpo/core/arti/-/commit/efdd327569990cd9e4d7678bae2ac406baf7b1d5

# Arti 0.0.1 — 29 Oct 2021

This release attempts to be "free of known privacy holes". That
isn't to say that there are no remaining bugs, but rather that we've
implemented the missing features that we think are essential for
basic privacy.

### New features

- Guard relay support... ([#58])
  - ...with "Lightweight" path bias detection. ([#185])
- Circuit isolation API. ([#73], [!104])
- Circuit build timeout inference. ([#57])
- Persistent state on disk. ([#59])
- Allow multiple Arti instances to share directories. ([#194])
- Support for EnforceDistinctSubnets. ([#43])
- Configurable logging ([!68]) to journald. ([!73])
- Rejecting attempts to connect to internal addresses. ([#85])
- Support for Tor `RESOLVE` and `RESOLVE_PTR` [socks extensions]. ([#33])
- And too many others to list.

### Breaking changes

- Switched from `log` to `tracing`. ([#74])
- Renamed `arti-tor-client` to `arti-client`. ([#130])
- Stopped exposing `anyhow` errors. ([#165])
- CLI now uses `clap`, and uses subcommands. ([!109])
- Too many others to list.

### Documentation

- New top-level documentation for `arti-client`, with examples. ([!111])
- Many other improvements and rewrites.

### Infrastructure

- Reproducible builds for Linux ([!69]), Windows ([!70]), and OSX ([!86]).
- Support for static binaries. ([!69])
- Simple integration tests, using [chutney] ([!88]).

### Cleanups, minor features, and bugfixes

- Too many to list.

### Acknowledgments

Thanks to everybody who's contributed to this release, including Ben
Armstead, Daniel Eades, Dimitris Apostolou, Eugene Lomov, Felipe
Lema, Jani Monoses, Lennart Kloock, Neel Chauhan, S0AndS0, Smitty,
Trinity Pointard, Yuan Lyu, dagger, and rls!

[#33]: https://gitlab.torproject.org/tpo/core/arti/-/issues/33
[#43]: https://gitlab.torproject.org/tpo/core/arti/-/issues/43
[#57]: https://gitlab.torproject.org/tpo/core/arti/-/issues/57
[#58]: https://gitlab.torproject.org/tpo/core/arti/-/issues/58
[#59]: https://gitlab.torproject.org/tpo/core/arti/-/issues/59
[#73]: https://gitlab.torproject.org/tpo/core/arti/-/issues/73
[#74]: https://gitlab.torproject.org/tpo/core/arti/-/issues/74
[#85]: https://gitlab.torproject.org/tpo/core/arti/-/issues/85
[#130]: https://gitlab.torproject.org/tpo/core/arti/-/issues/130
[#165]: https://gitlab.torproject.org/tpo/core/arti/-/issues/165
[#185]: https://gitlab.torproject.org/tpo/core/arti/-/issues/185
[#194]: https://gitlab.torproject.org/tpo/core/arti/-/issues/194
[!68]: https://gitlab.torproject.org/tpo/core/arti/-/merge_requests/68
[!69]: https://gitlab.torproject.org/tpo/core/arti/-/merge_requests/69
[!70]: https://gitlab.torproject.org/tpo/core/arti/-/merge_requests/70
[!73]: https://gitlab.torproject.org/tpo/core/arti/-/merge_requests/73
[!86]: https://gitlab.torproject.org/tpo/core/arti/-/merge_requests/86
[!88]: https://gitlab.torproject.org/tpo/core/arti/-/merge_requests/88
[!104]: https://gitlab.torproject.org/tpo/core/arti/-/merge_requests/104
[!109]: https://gitlab.torproject.org/tpo/core/arti/-/merge_requests/109
[!111]: https://gitlab.torproject.org/tpo/core/arti/-/merge_requests/111
[chutney]: https://gitlab.torproject.org/tpo/core/chutney
[socks extensions]: https://gitlab.torproject.org/tpo/core/torspec/-/blob/main/socks-extensions.txt

# Arti 0.0.0

Initial release, to reserve our crate names on crates.io.