[draft] Switch THP implementation to rust/trezor-thp

[mmilata]

Lots of major parts still missing/broken and plenty of smaller TODOs, hopefully the rough shape stays the same. See also #6442.

• Does not yet work well with session restarts as the read loop reads packets too eagerly and ends up reading the next message just before loop restart and it gets lost. Probably solvable by adding another mailbox but I want to wait before preemption works.
• Tentative trezor-crypto integration. Since it should now be possible to use unpatched noise-rust for clients I'd reevaluate implementing the device side of Noise directly in trezor-crypto. If we decide to go with noise-rust then at least zeroization is missing here.
• Channel preemption.
• ACK piggybacking.
• Delete sessions whenever their channel gets deleted.
• Turn async functions into generators where possible.
• Interface write timeouts.
• Make the code readable.
• Split off rust/trezor-thp changes into separate PR.

Overview:

• On the rust side channels are kept in global arrays which are unaffected by workflow restarts. Send/receive buffers are managed by micropython and are passed to rust when needed but reference is never kept. Credential verification calls into python which introduces a bit of weirdness.
• In micropython every interface spawns three loops:
  • Read loop waits on an interface and passes received packets to the rust module which returns events like "message complete" which are then handled.
  • Write loop waits on a condition variable (mailbox) and when it's woken up it asks if the rust module has packets to send and pushes them into the interface.
  • Timeout loop waits on a timer and initiates retransmissions when needed.

Note: retest #6348 before merging.

[coderabbitai]

Important

Review skipped

Draft detected.

Please check the settings in the CodeRabbit UI or the .coderabbit.yaml file in this repository. To trigger a single review, invoke the @coderabbitai review command.

⚙️ Run configuration

Configuration used: Organization UI

Review profile: CHILL

Plan: Pro

Run ID: ec0af57c-0ad8-45bf-b743-1e18fcf83074

You can disable this status message by setting the reviews.review_status to false in the CodeRabbit configuration file.

Use the checkbox below for a quick retry:

• 🔍 Trigger review

✨ Finishing Touches

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch mmilata/thp-riir-trezor

---

Thanks for using CodeRabbit! It's free for OSS, and your support helps us grow. If you like it, consider giving us a shout-out.

❤️ Share

• X
• Mastodon
• Reddit
• LinkedIn

_{Comment @coderabbitai help to get the list of available commands and usage tips.}

[github-actions]

Looks like you changed Cargo.lock. Please make sure to review the dependencies and update internal version list.

[github-actions]

en main(all)

model	device_test	click_test	persistence_test
T2T1	test(all) main(all)	test(all) main(all)	test(all) main(all)
T3B1	test(all) main(all)	test(all) main(all)	test(all) main(all)
T3T1	test(all) main(all)	test(all) main(all)	test(all) main(all)
T3W1	test(all) main(all)	test(all) main(all)	test(all) main(all)

Latest CI run: 25108356485

[socket-security]

All alerts resolved. Learn more about Socket for GitHub.

This PR previously contained dependency changes with security issues that have been resolved, removed, or ignored.

View full report