We are planning to integrate with external secret operators, like AWS secret manager or Openboa/Vault so users can benefit from an end to end secrets protection. secret encryption/sealing at rest (through secrets managers) and protecting secrets from in-memory exfiltration attacks with kloak.
The idea is to let the ESO handle the secret at rest and delivering it to Kloak that then would continue to do the kloaked secret rewrite so the secret will only be available in a non encrypted form in Kloak. We can even push the concept further and do KMS decryption just in time to reduce the window where the secret is available.
- send traffic to the proxy (either in a non transparent way or using routes or even ebpf to redirect traffic to the proxy transparently)
- trust the proxy certs or use plain http/TCP to the proxy
With kloak, the app don't need any modification and you avoid a single point of failure (aka egress proxy). Each app has an independent ebpf program attached to it that can survive the control plane going down and don't need to trust any special certs or change the endpoint it sends traffic to.
cool, but the single point of failure (it could be HA-proxy) is the point, it's a choke point. I get both architectures have pros and cons, with the proxy approach you remove secrets from the application environment entirely. Plain HTTP shouldn't be an issue, neither should internal certs whose only point is to allow applications that refuse to work with plain-http to function. I would prefer the best of both worlds, where the proxies are per-node personally.
But not everyone wants to, or can afford to run a proxy for credential management. I started looking into this mostly to regulate API usage, especially burning through tokens when calling LLM apis, the credential benefit only occurred to me afterwards. Great work with it, no idea how the eBPF magic is making it work, I'll have to find out.
Thank you!
I agree, each architecture have its pro and cons. If an egress gateway is available and can handle secrets it's definitely a viable solution.
This is not something we support currently. We will need to do some research on ways to support it.
The main hurdle is that we can't rewrite secrets in any of the user buffers as this will defy our threat model and signing is usually done in user space.
You are already doing a MITM, so some one is placing the trust in you as a intermediary. In reality the content distribution networks fronting any of the API operations have already muddied the water at this point. You are well into your rights to recalculate the signature for the payload and replace it with the secret key.
yes I agree and we actually already do that for TLS when rewriting secrets after encryption but my point is about the fact in our threat model we consider the app as an adversary so we don't want to use any of its buffers to rewrite secrets because it would be trivial for an adversary to reread the buffer after rewrite and get the secret. The way we overcome this is by listening to the user buffer recording all the data we need to rewrite the secret without writing anything. We go back later in the kernel buffer meant to be sent to the network and not accessible to the user app and perform the rewrite.
For API keys used to sign the request we need to do something similar which could be challenging within ebpf (maybe doable I'm not sure)
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
How does this compare with TPUs? Can you not have secrets in the TPU which cannot be accessed directly by apps, solving this threat vector? I get that you want compatibility with popular libraries, but I wonder if the actual solution is to use hardware support to enforce the secret boundaries.
I'm not super familiar with TPUs and Trusted execution environments but my understanding is that it serve a different threat model.
TEE aim to protect a certain workload from the host to avoid another workload on the same host from steeling secrets.
Kloak aim is to protect the secret from the workload itself not the 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.
Actually we have 2 applications along those boundaries you described. a webhook app that manage kubernetes manifest and another to inject the ebpf code and manage the ebpf maps.
Thank you for the feedback though! I think we need to clarify the doc to make that separation clear. I will open an issue for that and we will work on it.
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.
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.
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 :)
- My specific usecase is to not need Conjur Secretless Broker (https://github.com/cyberark/secretless-broker) - my understanding of eBPF is entirely superficial but from a 30k ft view, it looks like this can not only replace it but would be a far efficient solution (Conjur would be a user-space proxy while kloak would be at lower levels of abstraction)?
yes please open an issue on https://github.com/spinningfactory/kloak/issues and we can discuss this. I'm not familiar with secretless-broker but we can definitely see if that use case fit with kloak and get into more specifics on how you can help.
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.
The way we thought about it is from the lense of 2 personas:
- a persona that control the control plain side, what secret to distribute to which user and what hosts they are allowed to send that secret to (probably platform team or secops team)
- a persona that represent the user that need to reach host X with secret Y (probably the dev team)
based on this secret rewrite signal need to be out of band and not part of the request it self or the whole model will fall apart.
We already have the intention to support rewrites for specific headers but those headers are defined by the first persona out of band too.
btw, we support rewrite for postgres protocol for db password.
For security products trust is important. writing your website copy by hand will help you build trust. If the design and content does not look human written it will lower adoption.
Thank you for the feedback! We are currently shorthanded so we relied on AI a lot for writing our docs, we reviewed that doc as much as we could but definitely there is room for improvement. We will try to get better at this.
In the mean time, if you find any discruptency with the docs or anything that we can correct please open an issue and we will get to it ASAP.
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.
it's not a war Netanyahu is killing innocent people and taking a full population hostage.
Also, most of the people in Gaza are not Hamas members and are regular civilians. What Natanyahu is doing is basically analog to the following:
A killer take a member of your family as a hostage (Hamas in this case is the killer) so you decide to kill a member of their family every hour until they release your beloved one. Do you think that this is acceptable or are you trying to make it acceptable?
Do you know why you have so many videos of buildings being destroyed in the Gaza strip? Because Israel warns away civilians before destroying them. Doesn't sound to me like Israel is trying to kill civilians.
I often stack PRs to emulate the practice described by Mitchell but it's not ideal as if you need to change an underlying PR l, you need to rebase all of the dependent PRs.
There are tools that solve this problem! I work on one (Graphite), but there's also plenty of others like git-branchless and Sapling. All three of these are inspired by Facebook's internal fork of Mercurial (with Phabricator/"Diffs" for reviewing) -- Google has a similar model with Piper/Critique CLs, with Gerrit as the open source result.
So Facebook is still using Phabricator? Somehow I suspected that they had abandoned it since they seemingly stopped being involved in the open source Phabricator project.
There's a ton of cli tools to automate maintaining a stack of PR's, with new ones coming out all the time. I've seen 'spr' for a long time, and recently there's graphite's and even aviator came out with 'av'.
All supported by Reviewable, of course (sorry for the shameless plug!)
We are planning to integrate with external secret operators, like AWS secret manager or Openboa/Vault so users can benefit from an end to end secrets protection. secret encryption/sealing at rest (through secrets managers) and protecting secrets from in-memory exfiltration attacks with kloak.
The idea is to let the ESO handle the secret at rest and delivering it to Kloak that then would continue to do the kloaked secret rewrite so the secret will only be available in a non encrypted form in Kloak. We can even push the concept further and do KMS decryption just in time to reduce the window where the secret is available.
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