OpenSK VS smoltcp

https://github.com/google/OpenSK works, it runs on something like this $15 board. Could do with a case though.

https://www.nordicsemi.com/About-us/BuyOnline?search_token=n...

There are a huge number of other vendors supporting Webauthn apart from Yubikey. (From the top of my head Nitrokey, Solo, Tomu, Mooltipass, Ledger, Trezor, Google Titan, OnlyKey, Token2).

You could also use the system TPM (https://github.com/psanford/tpm-fido).

A brief search didn't yield any FIDO2 software-only solutions for Linux, but I see no reason why in principle you couldn't implement it (perhaps interfacing https://github.com/google/OpenSK through hidg - similar projects do exist for U2F).

Cloudflare does, using a security key not found in the FIDO Metadata Service will unfortunately not work. This precludes the use of any hacker-friendly solution (making your own).

> Supported: All security keys found in the FIDO Metadata Service 3.0, unless they have been revoked for security reasons.

https://support.cloudflare.com/hc/en-us/articles/44068890480...

Attestation keys, as they're currently used, aren't very "privacy friendly" and it's much worse for those who wish to create their own key.

> Usually, the attestation private key is shared between a batch of at least 100,000 security keys of the same model. If you build your own OpenSK, your private key is unique to you. This makes you identifiable across registrations: Two websites could collaborate to track if registrations were attested with the same key material. If you use OpenSK beyond experimentation, please consider carefully if you want to take this privacy risk.

https://github.com/google/OpenSK/blob/f2496a8e6d71a4e8388849...

There are a number of FOSS solutions.

- https://github.com/google/OpenSK <- DIY solution

- https://solokeys.com/

- https://www.nitrokey.com/

The issue with any FOSS solution is that FIDO requires an attestation private key which is shared between a batch of at least 100,000 security keys. Using a DIY or cli app (application running on the host) solution will likely mean you'll be generating that private key yourself, this makes you identifiable across registrations.

I'm not sure what you're replying to--this scheme is much closer to self-signed X509 client certs, not FIDO. But regarding FIDO, it does not prevent user-controlled hardware; it's up to RPs to choose if they require specific device manufacturers or not.

In my experience, the vast majority of (consumer) RPs do not require specific batch attestation, which is why you can make your own FIDO key: https://github.com/google/OpenSK.

I am under the impression support for attestation was controversial in FIDO--it's clearly useful for enterprise scenarios (e.g. where an enterprise requires some silly certification like FIPS: https://support.yubico.com/hc/en-us/articles/360016614760-Ac...), but there's always the risk that consumer-facing RPs require it for no good reason.

My employer requires FIPS certification due to FedRAMP; I'd be interested in how you would propose to change FIDO such that--as now--I can use a single key for work and for all my consumer needs while eliminating attestation.

There is also the Rust TCP/IP stack https://github.com/smoltcp-rs/smoltcp which is not mentioned as reference (and it's probably more useful to have a look there than querying ChatGPT).

Trying to dig out a link for you, will edit when I find it; TCP and Layer 4 raw sockets do not play nicely together on many platforms. You’ll probably have to send at the datalink layer and/or use something like https://github.com/smoltcp-rs/smoltcp

This seems close to what you're asking for: https://github.com/smoltcp-rs/smoltcp

A small-ish tcp/ip stack, in rust.

You can look into smoltcp

smoltcp

This here is a kernel including a memory-safe TCP/IP stack (https://github.com/smoltcp-rs/smoltcp/), and not having it crash or be full of security vulnerabilities due to preventable memory corruption is a quality beyond personal language preferences.

Oh, and you also probably want to check out smoltcp, a userspace/"no operating system required" networking stack that we often use in embedded rust.