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!

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.