I found OxiSH: a modern, memory-safe SSH server at Dirkjan Ochtman: writing
Sounds potentially very interesting. I was thinking of migrating from open ssh to some simpler implementation. I don’t really see any value in having password authentication, and I was postponing regenerating my RSA key with the Ed25519.
It implements hybrid post-quantum key exchange using the mlkem768x25519-sha256 algorithm, and curve25519-sha256 is supported for key exchange as a fallback algorithm for older clients. Ed25519 and ecdsa-sha2-nistp256 are the only supported public key algorithms, AES-128-GCM is the only supported encryption algorithm and SHA-256 is the only supported hash algorithm. It should be fairly easy to add other algorithms that are supported by the underlying backends, but I’d like to keep the set as small as possible to reduce attack surface.
This and Windows being out of scope, paint me interested!