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faithraven
Tapo (Rust/Python library) now speaks TP-Link's TPAP protocol mihai.dinculescu.dev

teravor5 hours ago

since GLM 5.2 (perhaps even earlier?) it has been remarkably easy to reverse engineer any closed protocol you want as long as you have a binary. previously, it required so much manual effort as to simply not be worth it 95% of the time.

now all you need is IDA or Ghidra MCP, a binary and some vague sloppy instructions.

some more recent models even started instrumenting a running binary (when possible) to enumerate the protocol without being explicitly instructed to, which is even better.

Retr0id5 hours ago

You don't even need an MCP, I just let the agent write scripts for headless ghidra. The MCPs are fragile and there isn't a whole lot of knowledge about how to use them in the training datasets, whereas there are plenty of ghidra scripts (and proper docs for the APIs).

bri3d4 hours ago

I agree! Don't give it away!

Seriously, though, the popular Ghidra MCP is really badly architected; it's way better to rearchitect it or just script Ghidra directly. With that said, Opus 5.5 seems to have been trained on CoT from the popular Ghidra MCP. This makes it work better, but also makes it even more inefficient if you modify the MCP without changing its name and shape significantly (it will try to make tool calls using the "mainline" format, then have to retry them when they fail).

Even with Opus 5.5, IMO it's better to just ditch the MCP and let the LLMs eat with bintools and headless Ghidra; with both GLM and Opus this produces significantly more efficient results than the popular MCP. On the other hand the IDA Pro MCP is much better architected and seems to be pretty good.

cute_boi3 hours ago

Will opus 5.5 even reverse engineer binaries? I get instant blocks when it sees word like decompile etc..

charcircuit3 minutes ago

Works fine for me. I didn't explicitly say decompile but it had no issue digging into executables to give me information on how it and various file formats were designed.

Retr0idan hour ago

It depends on what you're reversing. It tends not to like DRM-shaped things or security-sensitive things (for a very vague definition of "security-sensitive"), but e.g. game engines are fine. (For the things it doesn't like, dropping down to Opus 4.8 or 4.6 usually works)

teravor5 hours ago

    > there isn't a whole lot of knowledge about how to use them in the training datasets
if you include a SKILL.md for the MCP (or just dump it into the prompt) it's not a problem.

I don't use Ghidra but IDA Pro MCP works extremely well for me for all manner of tasks. for example, some software likes to call home for license checking (and I wish to run it with networking denied to it). it no longer does.

Retr0id5 hours ago

Sure, you can do that, but in my experience it's usually best to let agents do the things they already know how to do.

bri3d4 hours ago

The IDA Pro MCP is substantially better than the most popular Ghidra MCP, for what it's worth.

faithravenop5 hours ago

Without admitting to anything, I was surprised by how little time it took to add support for the new protocol to the library. And I didn't even need an MCP server.

thedougd3 hours ago

I've had good luck aiming for easier targets. Android APKs, Java, and .NET binaries are usually easy to reverse engineer with AI and without any advanced tooling.

nilamo4 hours ago

I feel like I'm either too dumb to get this, or not the target audience. I don't know what a Tapo is, but it's apparently a library to interact with Tapo devices, whatever that might be. And now it can talk TPAP, whatever that is. TP-Link is mentioned, so I'll guess Routers and move on :)

john_strinlai4 hours ago

https://www.tapo.com/us/

>Tapo is a brand of TP-Link that offers smart home solutions, such as security cameras, plugs, bulbs, switches, and more.

and TPAP is the "TP-Link Authentication Protocol" which, i believe, is based on 802.1X (https://en.wikipedia.org/wiki/IEEE_802.1X)

altmanaltman3 hours ago

Tapo devices are basically smart home stuff. You normally have to use their ecosystem to control those devices, i.e. use their apps etc. However, people do not like the fact that you're locked in those apps and want to use those devices via platforms like Homeassistant, so people figure out how to do it by tricks like this.

originalvichyan hour ago

They’re also a cheap way to get into BirdNET and Apple HomeKit Secure Video if you get their cheapest security cams that have some weather proofing. You can get a microphone (and camera) outdoors without having to shell out a lot of money for a Raspberry Pi + microphone + all the protective casing required to keep it from breaking.

With software like Scrypted or Frigate, I was able to use an Apple TV 4K to get a security feed into my Apple Home with iCloud+. You don’t need to buy Homekit certified product.

dawnerdan hour ago

They're also really cheap energy monitoring plugs, probably the cheapest from a known brand you can get. I also really like their light switches and they work great in HA. FWIW I also have them completely locked down on the network like all other IOT devices.

mplewis20 minutes ago

Reads like AI slop.

faithravenop6 hours ago

Author here. tapo is an unofficial Rust client library for TP-Link Tapo devices (plugs, lights, hubs, cameras), with a Python wrapper built on the same crate. It is not affiliated with TP-Link.

The short version: since late 2025, firmware updates have made Tapo devices refuse third-party clients unless you turn on a "Third-Party Compatibility" switch in the Tapo app. The switch works by bringing back the older login, KLAP. With it off, devices speak an undocumented protocol called TPAP, which logs in with SPAKE2+ (RFC 9383). The library now speaks TPAP, so the switch can stay off.

The part I found most interesting is the security difference. A recorded KLAP login can be used to test password guesses offline. With SPAKE2+ it can't, and learning the password later doesn't decrypt sessions captured earlier. So the "compatibility" switch is really a security downgrade, and TP-Link's own FAQ says enabling it "may reduce the security of your devices".

Not everything works with the switch off yet: some cameras, such as a C210 on firmware 1.5.2, still need it on.

Happy to answer questions about the protocol work or the library.

tomhowan hour ago

We appreciate you posting your work and engaging in the discussion. But it's a no-no on HN to post comments that are generated (including polished or translated) by LLMs or other text-generation tools.

See https://news.ycombinator.com/newsguidelines.html#generated and https://news.ycombinator.com/item?id=47340079.

Please write all comments by hand, from your own thoughts, and resist the temptation to copy+paste anything from a chatbot or translation tool.

bonoboTP15 minutes ago

The article is also AI, I recognize its style from a mile away. I don't mind it super much when it's yapping like this about what it did for the tasks that I myself gave it, but I don't enjoy it for reading pleasure on the off-times.

mindcrime26 minutes ago

Totally AI-generated, sure. But saying "No AI edits" at all is going way too far, IMO. Taken to its logical extreme, that even bans using a spell-checker. And what about non native English speakers? Is it really wrong for them to use a translation tool so they can participate?

I mean, it's y'all site, you can do what you want. But FWIW, I think making that too much of an absolute "bright line" is a net negative for HN.

egworan hour ago

I've built the same code but in swift. I've come to the exact same conclusions that you have on the protocol. I got Claude Code to implement TPAP compatibility solely by interacting with my local plugs, looking at the shape of responses and RFC 9383 to figure out it was SPAKE2+. It took a bit of time to figure out the last bit: that the SHA-1 of the password, then PBKDF2 with the plug's salt, split into two halves; a context of "PAKE V1" plus both sides' random numbers; empty identities

sslalready2 hours ago

Awesome work. Here is hope this will also help improve local access to Tapo devices in Home Assistant.

tclancy5 hours ago

This is awesome, thanks for the work. I wish I'd come across it sooner.

the-grump4 hours ago

One thing to keep an eye out for is a communication from TP link telling you to stop using their name.

Great work!

mindslight5 hours ago

I have a handful of old TP-Link wifi switch devices, but I haven't kept up on the play by play developments. I just know at some point newer ones stopped working with that access method (and I haven't bought any since).

Is KLAP that old local-network UDP protocol with "XOR encryption" ? Or is that something else?

Does using TPAP with your library still require connecting the devices to their "cloud" (warning: surveillance!) ? Or does your library effectively restore the local-only workflow of never allowing the devices Internet access, and controlling them locally ?

faithravenop3 hours ago

That XOR protocol is a different one, and older than anything in the article. It is the original TP-Link Smart Home protocol used by the Kasa line (HS100, HS110 and similar): JSON on port 9999, obfuscated with an XOR autokey cipher, with no authentication at all.

Tapo devices never spoke it. Their original protocol was an AES passthrough over HTTP, KLAP replaced that in 2023, and TPAP is the newest. As far as I know, newer Kasa hardware and firmware moved to KLAP as well, which would explain why your access method stopped working on the newer ones. My library only covers Tapo devices; for Kasa, python-kasa is the one to look at.

On the cloud: the devices do have to be set up through the phone app with a TP-Link cloud account. Once set up, though, most functions of most devices can be used locally through the library, with neither the devices nor the library having internet access. The main catch is credentials: if you change the account password, for example, the devices need to be online for a little while to pick up the new one.

tecleandor4 hours ago

Note that KLAP, afaik, is only for the TAPO range of devices. Those are mostly cameras, doorbells, sensors, robot vacuums, and the like.

faithravenop3 hours ago

And plugs. Don't forget the plugs! Everyone loves their smart plugs :)

pkilgore6 hours ago

I was always taught: Read good books, that's how you'll write.

I don't even really care AI or human if its written like this. I would rather do anything else than continue reading.

IshKebab6 hours ago

Hard to disagree. I'm interested, but... the writing sucks.

And there's no excuse now anyway the latest Opus/Astra models are actually tolerable. Use those if you must.

nicce4 hours ago

The point of the writing is thinking what you are about to say from difference perspectives. Now, everything gets average and boring if LLMs are getting used all the time. And they still waste so many words that don't benefit reader in any way.

kurthr3 hours ago

I'm thinking it might be ESL and/or translated, but I could be wrong. There are posts from 2022, but they seem a lot more terse.

Not being able to effectively proofread will make slop even sloppier.

faithravenop6 hours ago

I did my best with the writing, but it clearly didn't land for the two of you. Could you point to one thing, or one pattern, that bothered you most? That would help me improve it.

ssl-3an hour ago

I dare say: All of it. All of it is bad. The parts are bad. The sum of the parts is also bad.

It starts in a weird way, by trying to play on a familiarity when the reader doesn't necessarily possess that familiarity at all.

It then continues to get weirder, and preachier, like the ramblings of someone who really likes to hear themselves talk but who doesn't actually have much to substance to convey at all.

Like: That's the headline of nearly four months of work? No. That kind of superlative statement is just a waste of space, and it's wrong anyway: The headline is the headline, and that headline is at the top of the page.

Seemingly every single paragraph is trying harder than the last one to try to sell itself. It's an awful body of work.

It reminds me of the stuff I hear in the city when the guy is standing on the corner shouting his continuously-impactful view of some damned thing or other, and who is both impossible to ignore and impossible to listen to.

The relief I experience when I get to move on -- away from that person's voice -- is immense, like the relief of moving away from https://mihai.dinculescu.dev/posts/tapo-speaks-tpap/ is also immense.

gfody24 minutes ago

this is an interesting specimen. vitriol is off the charts even for a solicited critique - I suspect here is a case where the pangram verdict is acting as a sort of license for the critic to treat the author as subhuman

the-grump7 minutes ago

@dang I don't know if there's anything you do about people being pricks for no reason like they are above in this thread.

mplewis20 minutes ago

Did you do your best? I think you can do better.

altmanaltman3 hours ago

What do you think is bad about the writing? It seems fine to me. What do you mean by "written like this"? What is this?

lmz2 hours ago

It's written like one of those long form magazine articles. Which is fine for that kind of thing but maybe not great for software release notes. It goes buildup buildup buildup ... underwhelming payoff.

ptx3 hours ago

The disclaimer at the end of the article says AI was used to "polish" the writing. I would guess it's this polish that can be a little off-putting: It reads like a magazine article written by and for people who aren't particularly interested in the topic.

gfody3 hours ago

[flagged]

faithravenop3 hours ago

My lacklustre writing skills aside, that garbage needs to be called what it is.

It is either satire designed to grab engagement by shocking people, or the genuine anti-AI frustration of a mediocre writer who has realised they've lost their edge, because their work isn't worth paying for over AI.

The people winning literary awards will keep winning them with their manual writing, and they will keep making good money ghostwriting.

But my article, which is meant to communicate some software features in decent, readable prose, isn't worth $10k of ghostwriting. AI will have to do. So you go get, sir, and please stop gatekeeping! (Not you specifically, you get my drift.)

The Economist recently published a piece on this very subject, too, and I found it a good listen: https://www.economist.com/by-invitation/2026/09/07/this-arti...

gfody15 minutes ago

> It is either satire designed to grab engagement by shocking people

it is satire - it's trying very hard to be obvious about it, yet amusingly still fails to get thru now and then

it's an attempt to get inside the head of those people who rush over from one of the various syndicates, pangram verdict in hand, to slam any and all ai writing - usually with pre-cooked burns, uninterested in the actual substance - the ai shout-down brigade

notJiman hour ago

The unchanged AI style is grating to read. I'd rather read the bullet points you fed to your AI than this style. Of course I'd really rather read your own quirky writing style (which identifies you as a human), but if you don't have the bandwidth for that, just post the prompt.

cloudfudgean hour ago

In all honesty, I read your whole page and didn't find it one bit distracting or noticeable. I got to the end and saw the disclaimer about the AI writing and thought, "well, at least that'll head off the inevitable bitching about it being AI writing." Then I came to HN and saw people acting like you were committing atrocities. Sigh.

exographicskip3 hours ago

That was a good read! Bit of a diatribe and don't wholly agree, but I can empathize with the author

the-grump4 hours ago

Were you not also taught to "say something nice or nothing at all?"

There's no reason to be this nasty. If you don't like the writing, skip the post.

For what it's worth, the writing is clear and it gets the point across.

OP, thank you for doing the work and for sharing it.

cute_boi3 hours ago

How is he being nasty?

I can bet author didn't even read his own AI generated text.... I don't have any issue with AI, but it would be nice if people spend time over creating quality stuff.

the-grump4 minutes ago

You don't see how it's nasty, and then you pile your own nastiness on top.

Get a life and read something you want to read instead of spilling your bile on somebody sharing their work.

faithravenop3 hours ago

Sorry to disappoint, but I did. Multiple times, across multiple days.

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