This is pretty cool, nice project. Can you expand on what threat model this combats?
Also, does the replace op happen only for specific fields in HTTP, or for every matching string in the request? I can imagine the latter if you want to support non-standard authentications methods, though there's always the edge case where the secret string placeholder is not used as a secret and should not be replaced.
The main threat model is application leaking secrets:
- Internet facing app that could potentially be hacked and bad actor exfiltrating secrets
- AI agent that can exfiltrate secrets through prompt injection for example or context poisoning
- The general use case where a secret can be for example inject by mistake in logs for instance
Hey, we're the spinning-factory team, the folks behind Kloak.
Kloak runs as a Kubernetes controller. It swaps the secrets in your workloads for harmless placeholders we call kloaked secrets, then uses eBPF to substitute the real secrets back in at the last moment — right when your app makes a request to an allowed host.
Today, Kloak works with any app using OpenSSL 3.0–3.5 (statically or dynamically linked) or go-tls (Go 1.25 and 1.26). Support for more TLS libraries (GnuTLS, BoringSSL, and others) and additional Go versions is on the roadmap.
Kloak is open source under the AGPL, contributions are welcome! We are also happy to hear any feedback and answer any question for the HN community.
Secrets are detected before encryption in the user buffer but rewrites happen post encryption in the kernel buffer to be sent on the wire.
packets boundaries are not an issue because detection happen at the SSL write where we have the full secret in the buffer and its position so we can know at rewrite time that the secret is cross 2 packets and rewrite it in 2 separate operations. We also have to update the TLS session hash at the end to not corrupt the TLS frame.
This is fantastic! I need this. however, for my self-hosted home projects that are containerized but where I don't use Kubernetes, is there a way for me to use a version of Kloak that does the same eBPF magic on docker-compose or LXC/QEMU (Incus) stacks?
It's perfectly fine for you to say non-Kubernetes isn't either your focus or on your 90 day roadmap :)
Thank you! We appreciate your enthusiasm! :-)
From technology perspective nothing prevent kloak to do rewrite on any workload scheduler or even without a scheduler (native Linux). The main challenge is to find a flow to signal to kloak what to rewrite and how to inject kloaked secrets to the workload.
TBH supporting other technologies is not something we thought about but we can definitely consider if there is an ask for it from the community.
I think it is funny that it's sewer, because a sewer is also a underground way around things, which is a good description of the out of band solution here. So the name checks out.
It should work in cloud environments, We tested it on EKS and digital ocean cloud so far, and it works. The kloak controller is deployed as privileged daemonset that have access to the underlying host and can perform eBPF attachment operations on all the pods on that host.
Thank you!
Not really, the controller is not doing dataplane per-say, it only pushes eBPF programs to the kernel for the relevant apps/cgroups so that could be considered control-plane. The full data-plane run in eBPF.
This is pretty cool, nice project. Can you expand on what threat model this combats?
Also, does the replace op happen only for specific fields in HTTP, or for every matching string in the request? I can imagine the latter if you want to support non-standard authentications methods, though there's always the edge case where the secret string placeholder is not used as a secret and should not be replaced.
The main threat model is application leaking secrets: - Internet facing app that could potentially be hacked and bad actor exfiltrating secrets - AI agent that can exfiltrate secrets through prompt injection for example or context poisoning - The general use case where a secret can be for example inject by mistake in logs for instance
we currently support rewrites for specific hosts and IPs and we have an open issue for supporting rewrite for specific headers for http/http2
Hey, we're the spinning-factory team, the folks behind Kloak. Kloak runs as a Kubernetes controller. It swaps the secrets in your workloads for harmless placeholders we call kloaked secrets, then uses eBPF to substitute the real secrets back in at the last moment — right when your app makes a request to an allowed host. Today, Kloak works with any app using OpenSSL 3.0–3.5 (statically or dynamically linked) or go-tls (Go 1.25 and 1.26). Support for more TLS libraries (GnuTLS, BoringSSL, and others) and additional Go versions is on the roadmap. Kloak is open source under the AGPL, contributions are welcome! We are also happy to hear any feedback and answer any question for the HN community.
So it reads the packets and replaces the byte sequences at the kernel level? How does that work across packet boundaries?
Secrets are detected before encryption in the user buffer but rewrites happen post encryption in the kernel buffer to be sent on the wire.
packets boundaries are not an issue because detection happen at the SSL write where we have the full secret in the buffer and its position so we can know at rewrite time that the secret is cross 2 packets and rewrite it in 2 separate operations. We also have to update the TLS session hash at the end to not corrupt the TLS frame.
This is fantastic! I need this. however, for my self-hosted home projects that are containerized but where I don't use Kubernetes, is there a way for me to use a version of Kloak that does the same eBPF magic on docker-compose or LXC/QEMU (Incus) stacks?
It's perfectly fine for you to say non-Kubernetes isn't either your focus or on your 90 day roadmap :)
Yeah you might have to go talk to incus folks on how to integrate this together.. They are fairly capable, might have some good direction.
https://discuss.linuxcontainers.org/t/how-to-best-ask-questi...
Thank you! We will reachout and see what can be done
Thank you! We appreciate your enthusiasm! :-) From technology perspective nothing prevent kloak to do rewrite on any workload scheduler or even without a scheduler (native Linux). The main challenge is to find a flow to signal to kloak what to rewrite and how to inject kloaked secrets to the workload. TBH supporting other technologies is not something we thought about but we can definitely consider if there is an ask for it from the community.
Yeah, so Kloak is Danish for sewer.
More or less straight from Latin?
https://en.wikipedia.org/wiki/Cloaca_Maxima
I guess we are the secrets sewers then! :D We would love to hear what you think about it beyond the name though.
I think it is funny that it's sewer, because a sewer is also a underground way around things, which is a good description of the out of band solution here. So the name checks out.
It was not intended! We were trying to make it sound like a cloak with a kubernetes K but I guess this explanation actually checkout better!
This is pretty awesome. Super relevant for the time because AI controlled workflows are desperate for a out of band solution like this.
The main thing I wonder is how well supported is it in cloud environements? AKS/EKS/etc?
It should work in cloud environments, We tested it on EKS and digital ocean cloud so far, and it works. The kloak controller is deployed as privileged daemonset that have access to the underlying host and can perform eBPF attachment operations on all the pods on that host.
gcp and aks were going to be the next ones on the testing list, but life sometimes gets in the way !
You should split your controller - it is running in both the control and data planes. Idea is good though, wish you luck.
Thank you! Not really, the controller is not doing dataplane per-say, it only pushes eBPF programs to the kernel for the relevant apps/cgroups so that could be considered control-plane. The full data-plane run in eBPF.
Aiui the controller is only running in the control plane, and the ebpf programs are in the data plane?
yes, that's right!