Phoenix Kahlo
73545b65b3
RFC 9000 presents some unfortunate complications to naming things. It introduces a concept of a "token" that may cause a connection to be validated early. In some ways, these tokens must be treated discretely differently based on whether they originated from a NEW_TOKEN frame or a Retry packet. It also introduces an unrelated concept of a "stateless reset token". If our code and documentation were to constantly use phrases like "token originating from NEW_TOKEN frame," that would be extremely cumbersome. Moreover, it would risk feeling like leaking spec internals to the user. As such, this commit tries to move things towards the following naming convention: - A token from a NEW_TOKEN frame is called a "validation token", or "address validation token", although the shorter form should be used most often. - A token from a Retry packet is called a "retry token". We should avoid saying "stateless retry token" because this phrase is not used at all in RFC 9000 and is confusingly similar to "stateless reset token". This commit changes public usages of that phrase. - In the generic case of either, we call it a "token". - We still call a stateless reset token a "reset token" or "stateless reset token".
Quinn is a pure-Rust, async-compatible implementation of the IETF QUIC transport protocol. The project was founded by Dirkjan Ochtman and Benjamin Saunders as a side project in 2018, and has seen more than 30 releases since then. If you're using Quinn in a commercial setting, please consider sponsoring the project.
Features
- Simultaneous client/server operation
- Ordered and unordered stream reads for improved performance
- Works on stable Rust, tested on Linux, macOS and Windows
- Pluggable cryptography, with a standard implementation backed by rustls and ring
- Application-layer datagrams for small, unreliable messages
- Future-based async API
- Minimum supported Rust version of 1.71
Overview
- quinn: High-level async API based on tokio, see examples for usage. This will be used by most developers. (Basic benchmarks are included.)
- quinn-proto: Deterministic state machine of the protocol which performs no I/O internally and is suitable for use with custom event loops (and potentially a C or C++ API).
- quinn-udp: UDP sockets with ECN information tuned for the protocol.
- bench: Benchmarks without any framework.
- fuzz: Fuzz tests.
Getting Started
Examples
$ cargo run --example server ./
$ cargo run --example client https://localhost:4433/Cargo.toml
This launches an HTTP 0.9 server on the loopback address serving the current
working directory, with the client fetching ./Cargo.toml. By default, the
server generates a self-signed certificate and stores it to disk, where the
client will automatically find and trust it.
Links
- Talk at RustFest Paris (May 2018) presentation; slides; YouTube
- Usage examples
- Guide book
Usage Notes
Click to show the notes
Buffers
A Quinn endpoint corresponds to a single UDP socket, no matter how many
connections are in use. Handling high aggregate data rates on a single endpoint
can require a larger UDP buffer than is configured by default in most
environments. If you observe erratic latency and/or throughput over a stable
network link, consider increasing the buffer sizes used. For example, you could
adjust the SO_SNDBUF and SO_RCVBUF options of the UDP socket to be used
before passing it in to Quinn. Note that some platforms (e.g. Linux) require
elevated privileges or modified system configuration for a process to increase
its UDP buffer sizes.
Certificates
By default, Quinn clients validate the cryptographic identity of servers they connect to. This prevents an active, on-path attacker from intercepting messages, but requires trusting some certificate authority. For many purposes, this can be accomplished by using certificates from Let's Encrypt for servers, and relying on the default configuration for clients.
For some cases, including peer-to-peer, trust-on-first-use, deliberately
insecure applications, or any case where servers are not identified by domain
name, this isn't practical. Arbitrary certificate validation logic can be
implemented by enabling the dangerous_configuration feature of rustls and
constructing a Quinn ClientConfig with an overridden certificate verifier by
hand.
When operating your own certificate authority doesn't make sense, rcgen can be used to generate self-signed certificates on demand. To support trust-on-first-use, servers that automatically generate self-signed certificates should write their generated certificate to persistent storage and reuse it on future runs.
Contribution
All feedback welcome. Feel free to file bugs, requests for documentation and any other feedback to the issue tracker.
The quinn-proto test suite uses simulated IO for reproducibility and to avoid
long sleeps in certain timing-sensitive tests. If the SSLKEYLOGFILE
environment variable is set, the tests will emit UDP packets for inspection
using external protocol analyzers like Wireshark, and NSS-compatible key logs
for the client side of each connection will be written to the path specified in
the variable.
The minimum supported Rust version for published releases of our crates will always be at least 6 months old at the time of release.