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 0.1.0 — 1 Mar 2022

blurb blurb

(I've caught up, as to be288399ec)

This release marks the completion of our 0.1.0 milestone. With this milestone, we now consider Arti ready for experimental embedding within other applications.

Additionally with this release, we're now ready to declare the arti_client API more or less stable and supported. (We're not committing to never break it again in the future, but we'll try not to do so without pretty good reasons.) The 1.0.0 release, scheduled for this September, will represent an even stronger API commitment.

Breaking changes

• Our top-level Error type is now a mostly-opaque wrapper around an inner hidden ErrorDetail type. (You can access ErrorDetail by enabling a feature, but it breaks your semver guarantees.) To distinguish among different kinds of Errors, we provide a supported (and hopefully stable) ErrorKind API that developers can use. ([!262], [!291], [!325], [#322], [#348])
• The interface to construct a TorClient instance has been completely replaced. The new API should be stable, and prevent the need for additional breaking changes in the future. ([#350], [!364])
• Many smaller changes, too numerous to list. (Starting after this release, we will try be much more careful about breaking changes, and note them specifically here.)
• We no longer recommend the static feature flag; instead use static-native-tls or static-sqlite as appropriate. ([#302])

New features

• The Arti client can now watch its configuration files to see if they change, and reconfigure itself when they do. This is controlled by a watch_configuration option, and is off-by-default. ([#270], [!280])
• Unused channels now expire after enough time has passed. (This is mostly not needed on the client side, since relays also expire unused channels.) ([#41], [!273])
• You can now create an unbootstrapped TorClient object, so that you can observe its bootstrapping progress and/or bootstrap it at a later time. ([#293], [!298])
• You can configure an unbootstrapped TorClient object to automatically bootstrap itself the first time it's used. ([!322)
• Arti now returns a webpage with an error message if you try to use its SOCKS proxy as an HTTP proxy ([!348])

Major bugfixes

• Fixed a number of problems in the circuit Reactor implementation that could result in cell reordering, leading to relays closing our circuits because of protocol violations. ([!264], [!282])
• Fixed bugs that could cause strange behavior on shutdown or failure during circuit construction. ([#210], [#365], [!363], [!366])

Infrastructure

• Numerous CI improvements.
• Numerous coverage-testing improvements.
• We renamed our shell and python scripts to remove their ".sh" and ".py" suffixes, so that we can more freely change their implementations in the future (if needed). ([#309])
• The DirMgr crate now uses an abstract Store trait to make it easier for us to implement new storage backends in the future. ([!345], [!317])

Documentation and Examples

• Provide better sample code for TorClient::connect. ([!303])
• Provide an example for how to make a [lazy-initialized] TorClient object. ([#278], [!322])
• Provide an example for how to [override the default TCP-connect] implementation. ([!341], [!356])
• We now provide an example of how to use Arti with the [hyper] HTTP library. This takes the form of a usable [arti-hyper] crate.

Cleanups, minor features, and minor bugfixes

• Stop using : as a path character; it's reserved on Windows. ([!277])
• Avoid returning junk data from over-long directory downloads ([!271])
• Implement Debug and Display for many more types.
• We no longer deny(clippy::all); instead we only use warn(clippy::all) to prevent future clippy versions from breaking completely on our code. ([#338])
• As part of our Error refactoring and implementation of ErrorKind, we improved the Error objects in many individual crates for better accuracy and specificity.
• Fix a bug that caused us to flush our persistent state to disk too aggressively. ([#320], [!321])
• The arti proxy now starts listening on its SOCKS port immediately, rather than waiting for bootstrapping to complete. ([!333])

Acknowledgments

Thanks to everybody who has contributed to this release, including Daniel Schischkin, Dimitris Apostolou, Michael Prantl, tharvik, Trinity Pointard, and Yuan Lyu.

Arti 0.0.4 — 31 Jan 2022

This release adds support for bootstrap reporting and rustls, improves several APIs, fixes a few bugs, and adds numerous smaller features for future-proofing and correctness.

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

New features

• Add backends for exposing changes in bootstrap status, either to be queried by a function or read as a stream of events. These APIs will become more useful once there is a way to actually get an un-bootstrapped TorClient. (#96)
• TorClient now has a clone_with_prefs method to make a new client with a different set of default stream preferences. (7ff16fc252c0121f6607, #290])
• Add a feature for telling a TorClient that every stream should be isolated on its own circuit. Please use this sparingly; it can be inefficient. (!252)
• Convenience types for overriding parts of the behavior of an asynchronous Runtime. (!251)
• Optional support for rustls in place of native_tls. This is off by default; to turn it on, use the rustls feature, and construct your client using one of the Runtimes with Rustls in its name. (!260, #86)

Breaking changes

• Significant refactoring of exports and constructor functions in the arti-client crate. (!235)
• Change the persistence format used for guard information, to make it more future-proof. (#176)
• Functions and types that used to refer to "Connections" now refer to "Streams" for consistency. (!256)
• The types exported by the tor-rtcompat crate, and the functions used to create them, have been renamed for consistency. (!263)
• The Runtime API has changed slightly, to avoid a conflict with newer versions of async_executors. (bf8fa66d36298561cc86)

Major bugfixes

• Require authenticated SENDMEs when the relay supports them, and not otherwise. (#294)
• Fix the default location for the cache files. (Previously, they were put into the state directory.) (#297)

Infrastructure

• Numerous improvements to coverage tooling. (#248, !221, !269, !253)
• Improvements to arti-bench reliability and usefulness. (#292)
• Our CI now runs shellcheck on our shell scripts. ([#275])

Documentation

• Build instructions for iOS. (#132)
• Adopt a MSRV policy. (#283)
• More information about troubleshooting the build process. (#277)

Cleanups, minor features, and minor bugfixes

• The max_file_limit setting is now configurable. (#299)
• Fix an unreliable test. (#276)
• Fix a test that would always fail when run after January 27. (!268)
• Avoid possible incomplete reads and writes in Tor channel handshake. (1d5a480f79e7d878ff, !249])
• Refactor some types to expose Arc<> less often. (!236)
• Too many others to list!

Acknowledgments

Thanks to everybody who has contributed to this release, including Arturo Marquez, Daniel Eades, Daniel Schischkin, Jani Monoses, Neel Chauhan, and Trinity Pointard.

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!

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!

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!

Arti 0.0.0

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