A SSH client and server implementation. It is intended to be very flexible to embed pretty much anywhere, I'm collecting possible use cases in discussions. Don't hesitate to suggest something!
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sunset(this toplevel) is the core SSH implementation. It provides a non-async API, runs withno_stdand no alloc. -
sunset-async- async SSH client and server library, alsono_stdno-alloc. This is async-executor agnostic (using Embassy for mutexes, but works on std too). -
demoshas demos with Embassy executor for wifi on a Raspberry Pi Pico W or a Linux tap device onstdrunning locally.At present the Pico W build is around 150kB binary size (plus ~200KB cyw43 wifi firmware), using about 13kB RAM per concurrent SSH session.
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sunset-stdasyncadds functionality to use Sunset as a normal SSH client or server async library in normal Rust (notno_std). This uses Tokio or async-std.The examples include a Linux commandline SSH client
sunsetc. It works as a day-to-day SSH client.
Working:
- Client and server
- Shell or command connection
- Password and public key authentication
- ed25519 signatures
- curve25519 key exchange
- chacha20-poly1305, aes256-ctr ciphers
- hmac-sha256 integrity
- rsa (
std-only unless someone writes ano_stdcrate) ~.client escape sequences
Desirable:
- SFTP
- TCP forwarding
- Post quantum hybrid key exchange
- A std server example
- Perhaps aes256-gcm
- Perhaps ECDSA, hardware often supports it ahead of ed25519
At the time of writing Sunset will build with Rust 1.83. The requirement may increase whenever useful, targetting stable.
Sunset uses forbid(unsafe), apart from sunset-async which
requires unsafe for Unix interactions.
Release builds should not panic, instead returning Error::bug().
debug_assert! is used in some places for invariants during testing or
fuzzing.
Some attempts are made to clear sensitive memory after use, but stack copies will not be cleared.
Matt Johnston matt@ucc.asn.au
It's built on top of lots of other work, particularly Embassy, the rust-crypto crates, Virtue, smoltcp, and Salty.