Show HN: A WireGuard Powered Remote Shell

by dpeckett • 2 years ago

170 65 2 years ago

Time to announce Noisy Sockets Shell, the first in a series of WireGuard powered applications I'm working on. Noisy Sockets Shell is an SSH replacement that uses WireGuard for authentication and encryption, and WebSockets for communication.

CLI and browser client available.

codetrotter4• 2 years ago

What does this bring over binding sshd to the Wireguard interface address?

That’s what I do currently with some of my hosts.

ghxst• 2 years ago

Is there a small writeup available somewhere about this? I like the idea.

OMGWTF• 2 years ago

I guess you just need to configure `ListenAddress` in your `/etc/ssh/sshd_config` properly (see `man sshd_config`).

augusto-moura3• 2 years ago

I heard that ssh is kinda of an unnecessary step, since wireguard is already encrypted by default. Even legacy rsh should work fine in that setup. But I'm still not convinced, having double encryption is not a real performance problem in the real world. And I prefer it, just to be safe

yencabulator3• 2 years ago

SSH can authenticate a user, wireguard (as typically deployed) only authenticates a computer.

SSH can sometimes authenticate intent, like Yubikey touch.

Using wireguard for authentication is a mistake. The category of mistake is usually referred to as ambient authority, often exploited via a confused deputy.

MuffinFlavored3• 2 years ago

Why does the client have a listen port?

    nsh config init -c server.yaml -n server --listen-port=51820 --ip=172.21.248.1
    nsh config init -c client.yaml -n client --listen-port=51821 --ip=172.21.248.2

Typically, servers have easiest to configure NAT/firewall/port forwarding and clients (to me) are basically thought of as "not going to get through their router/firewall configuration no matter what".

dpeckett9• 2 years ago

Because WireGuard is a P2P protocol and if you want the server could be behind a NAT (eg. reverse shell). Very useful for accessing your home machine without having to open up a port etc. In the near future noisysockets will get NAT traversal support (with a Nebula lighthouse type server) which will make this use-case a lot simpler.

MuffinFlavored3• 2 years ago

I don't think this is accurate?

The flow I've seen is "Wireguard server has its listening port open. Clients (with all ports closed) connect to the server on its open port."

After that, all connections can still happen. Server -> client, client -> server.

NAT Traversal: The NAT entry created by the client's outgoing connection allows the server to send packets back to the client.
VPN Tunnel: The established VPN tunnel enables bidirectional communication, allowing the server to reach the client without the client needing an open port.

CapeTheory• 2 years ago

Looks like you created a bespoke license for your tool, which is your perogative but also means many people won't even consider using it.

MuffinFlavored3• 2 years ago

Why would people consider using it over "regular WireGuard setup with opensshd somewhere"?

betaby• 2 years ago

Perhaps to use it as a jump host. Oftentimes running ssh via ssh is not that good performance wise.

dartos2• 2 years ago

I was wondering the same thing, but another comment on this post pointed one out.

It’s clunky to distribute and rotate ssh keys, but much easier to do that with WireGuard credentials.

dpeckett9• 2 years ago

And that's totally fine :). It's worth noting that as a derivative of the FSL/BSL in four calendar years everything will be released back to the community under the MPL-2.0.

The shell implementation is already under the MPL-2.0 and worth a look at for anyone who's interested https://github.com/noisysockets/shell

yjftsjthsd-h3• 2 years ago

It's worth noting that as a derivative of the FSL/BSL in four calendar years everything will be released back to the community under the MPL-2.0.

A 4-year-old version of security-critical software. You understand why this is less than compelling?

nabla92• 2 years ago

It's worth noting that as a derivative of the FSL/BSL i

Maybe, but we don't know until we hire a lawyer to check it out. And we don't.

On the other hand, I don't think you can afford a lawyer to defend your bespoke license either.

In either case, the license is meaningless.

0xbadcafebee3• 2 years ago

If I can make a rough attempt at summarizing this: this is basically a PoC of a remote shell using the Noise Protocol Framework[1] with implementation Noisy Sockets[2] to effectively use UDP to tunnel a connection from one application to another directly and securely. If you squint at it, Noisy Sockets is basically like TCP+TLS, but UDP+SomeOtherCrypto. The library is a drop-in replacement for the Go 'net' library. All the protocols (including tcp/udp) are implemented in userspace.

This has some really interesting use cases (like not having to use HTTPS to get a bidirectional secure communication channel... not being limited by firewalls... not requiring an OS to upgrade its tcp/ip stack...). Normally I'm a pessimist but I kinda like this thing (the library, not the remote shell). Just needs a less clunky way to discover and route to services, a simpler way to configure a connection to the remote host, and extensible authentication/authorization (public keys pose management problems and don't fit some use cases).

That custom license may stop people from using the remote shell. Luckily the library is just MPL 2.0

[1] https://noiseprotocol.org/noise.html#introduction [2] https://github.com/noisysockets/noisysockets

dpeckett9• 2 years ago

Very good summary, and thanks for bringing up the license distinction, the noisysockets core library will always be MPL-2.0 and open to the community.

The fundamental thesis behind noisy sockets is, "What if your network endpoints were processes instead of machines?"

And as you say bypassing the host networking stack actually brings a lot of benefits (eg. avoiding those VPN leak shenanigans), it's actually interesting when you squint enough it begins to even look vaguely something like QUIC (in that you have multiple encapsulated streams/channels/sockets going over UDP with their own congestion control).

Peer discovery and NAT traversal are next on my list. I'm going to implement a kind of userspace lighthouse peer that will advertise peer endpoints to the network. I'm still trying to think about how I will deal with TURN/DERP. I suspect I'll tunnel WireGuard over WebSockets and just have each peer listen on UDP/TCP. Maybe one day that will allow even an in browser peer with WASM (which I'm sure someone will find an interesting use case for).

Also on the list is fine grained authentication/authorization (interestingly netstack has an iptables implementation), some of it will be opensource and some of it will be source available (sorry for the SSO tax).

0xbadcafebee3• 2 years ago

I feel like you're very close to an implementation which would finally break the HTTP hegemony on network protocols. I would strongly suggest looking at non-Web methods (I haven't done much research into TURN/DERP so I can't suggest anything specific)

I would also suggest looking at ZeroMQ if you haven't yet; their design & implementation is really fantastic. They implement the bare bones in the library, and then you can go implement your own components with it for whatever architectural topology you want. So for example, you could make a closed-source paid product of a connection broker using the library, and somebody else could make one for free as open-source. Both have their use-cases, and they're both compatible with all the other apps in the ecosystem. This benefits you as it legitimizes the product and grows the ecosystem, and encourages more use due to its flexibility

apitman• 2 years ago

I'm working on a simple protocol capable of tunneling TCP/UDP over WebSockets. Basically you can think of it as a way of providing QUIC/WebTransport functionality over WebSockets (multiple streams, backpressure, datagrams, etc). Reference implementation is in Go. Feel free to reach out if it might be useful.

louwrentius2• 2 years ago

Can you explain which problem this tool / these tools solve? I’m not sure I understand the purpose.

haiku2077• 2 years ago

A similar tool is Tailscale SSH. They replace SSH keys, which are clunky to distribute and invalidate, with the same authentication mechanisms you use for the rest of your digital security.

A great use case in the enterprise is wrapping old but mission critical systems that don't support modern encryption or authn requirements with WireGuard. SSH is a demo for that use case- there's a lot of proprietary TCP data protocols out there in the legacy enterprise world!

dpeckett9• 2 years ago

One of the things on my TODO radar is to implement a LD_PRELOAD'able Unix sockets implementation. Plus I need to get some additional language bindings done (eg. Python).

mrbluecoat• 2 years ago

Similarly, NetBird SSH: https://docs.netbird.io/how-to/cli#ssh

louwrentius2• 2 years ago

Thanks for the explanation!

dpeckett9• 2 years ago

Thanks everyone for the wonderful Sunday afternoon surprise, I'd posted this originally on a Friday and I guess a lot of us were out watching the polar lights. This was a fun project to work on.

Right now it doesn't support a multi-user daemon mode, kind of similar to mosh. But in the future because the server is able to cryptographically verify the source of connections, it's only a matter of time until I implement something akin to a per user `~/ssh/authorized_keys`.

With noisysockets I'm effectively building out a suite of WireGuard powered "apps". Which are small, unprivileged, programs you can attach to a WireGuard network and will act as virtual peers.

kzrdude• 2 years ago

To what extent does this replace mosh? https://mosh.org/

It seems like it could do some of the same usecases.

colordrops• 2 years ago

eternal terminal is better than mosh. it renders properly and provides scrollback.

dpeckett9• 2 years ago

Mosh was a big inspiration but I took a more traditional PTY based approach rather than object orientated updates.

One thing it does have in common with mosh, is excellent roaming support. And the other major selling point is that the remote shell protocol is browser compatible. No need for things like "Shell In A Box".

deadbabe3• 2 years ago

Hello, it’s my understanding that WireGuard isn’t very secure, but it is very fast. Is that correct?

dartos2• 2 years ago

No.

aborsy• 2 years ago

Wireguard is the most secure VPN protocol.

deadbabe3• 2 years ago

A quick google search seems to indicate OpenVPN is more secure.

cwaffles• 2 years ago

Wireguard is written by Jason Donenfield, a renowned developer with deep crypto knowledge. You can search him up and see for yourself. https://www.zx2c4.com/

deadbabe3• 2 years ago

Yes, I apologize to all who downvoted me, someone told me OpenVPN was still the more secure choice for a VPN.

dathinab• 2 years ago

One surprising tricky part of encrypting "live input" protocols (like typing send over a shell) is that just encrypting them is not enough.

You can use timing of packages send to e.g. extract passwords.

(hence why SSH clients normally take additional precautions)

josephcsible• 2 years ago

Would you consider dual-licensing this under a FOSS license like the AGPLv3? That's strong enough copyleft that I think you'll be safe from what you're trying to avoid with your current nonstandard license.

dpeckett9• 2 years ago

That's actually a really good suggestion, the main reason for using a time limited source available license was that I didn't want to impose a viral copyleft on everyone and lock up the code forever.

The custom license is a pretty basic derivative of the FSL-1.1 with MPL-2.0 instead of Apache (for a weak copyleft), I think I might keep the custom license in place (I'll make the very minimal changes from the stock FSL-1.1 clear).

But adding an AGPLv3 license for those with ambiguity concerns is totally okay with me (it's ultimately more restrictive than the source available license in a lot of ways).

Thank you for the great suggestion.

dpeckett9• 2 years ago

Done, the noisysockets CLI is now available under the AGPLv3 (and NSSL-1.0), pick the license of your choosing with no legal ambiguity. If it turns out the FSL-1.1, and by virtue of being a derivative the NSSL-1.0 is legally sound, after four years the code will be available under the MPL-2.0.

But you don't have to trust me, the AGPLv3 starts immediately.

I'll update the source headers in the following days.

Thanks!

efitz• 2 years ago

Pretty cool, but the license is pretty toxic to commercial adoption. I would suggest also licensing under MIT, BSD or Apache if you want this to ever achieve any widespread usage. Unfortunately you are competing against SSH which has a mature ecosystem so if you want widespread usage then you need to make it attractive legally as well as technologically.

zx2c4• 2 years ago

Why fork/copy&paste wireguard-go source code instead of using wireguard-go's existing netstack package? Couldn't you help improve instead?

Show HN: A WireGuard Powered Remote Shell

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