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Smuggling arbitrary data through an emoji

paulbutler.org

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Re: Smuggling arbitrary data through an emoji

#91

Post by ComputerGuru »

This is cute but unnecessary - Unicode includes a massive range called PUA: the private use area. The codes in this range aren’t mapped to anything (and won’t be mapped to anything) and are for internal/custom use, not to be passed to external systems (for example, we use them in fish-shell to safely parse tokens into a string, turning an unescaped special character into just another Unicode code point in the string, but in the PUA area, then intercept that later in the pipeline).

You’re not supposed to expose them outside your api boundary but when you encounter them you are prescribed to pass them through as-is, and that’s what most systems and libraries do. It’s a clear potential exfiltration avenue, but given that most sane developers don’t know much more about Unicode other than “always use Unicode to avoid internationalization issues”, it’s often left wide open.

Re: Smuggling arbitrary data through an emoji

#92

Post by remram »

jrootabega wrote: post #75
remram wrote: post #37

I'm not too surprised by this, but I'm annoyed that no amount of configuration made those bytes visible again in my editor. Only using hexdump revealed them.

Here's a POC that works in emacs. Doesn't cover all of the relevant characters, but: (setq ;;some other invisible or interesting characters unicode-zero-width-space ?\u200b unicode-zero-width-non-joiner ?\u200c unicode-zero-width-joiner ?\u200d unicode-zero-width-nbsp ?\ufeff unicode-narrow-nbsp ?\u202f unicode-word-joiner ?\u2060 unicode-grapheme-joiner ?\u034f unicode-no-break-space ?\u00a0 unicode-combining-long-s…

I use vim. It seems like `:set binary enc=latin1` works, though I don't understand why the latin1 part is required.

Re: Smuggling arbitrary data through an emoji

#93

Post by coldpie »

krupan wrote: post #89
coldpie wrote: post #84

Earlier quoted context omitted.

Yes, that's the reason for the "except for defensive purposes" part. Quoting from Red Hat's promise: > Our Promise also does not extend to the actions of a party (including past actions) if at any time the party or its affiliate asserts a patent in proceedings against Red Hat (or its affiliate) or any offering of Red Hat (or its affiliate) (including a cross-claim or counterclaim). Company B may still consult its por…

So in other words, Red Hat does not freely license their patents, they say "you are free as long as you don't come after us." Which is exactly the system 99% of companies follow, just more formally stated. Yet you berated the poor guy from Pebble for even obtaining the patent he did??

> Which is exactly the system 99% of companies follow, just more formally stated

Not just formally, but in a legally binding manner, including if the patent is acquired by another company (eg during a company purchase). Even if the original filer has the best intentions, companies change ownership or change legal strategy or go out of business. Patent trolls buy up those patents from closed companies. Legally licensing your patents for defensive-only purposes means they can't ever be used by any of those bad actors.

If the intent of these patents is truly only for defense, then why isn't it common to use a license like this? They lose nothing by it.

> Yet you berated the poor guy from Pebble for even obtaining the patent he did??

Yes. It is IMO unethical to create software patents that aren't covered by such a legally-binding license.

Re: Smuggling arbitrary data through an emoji

#94

Post by paulgb »

ComputerGuru wrote: post #91

This is cute but unnecessary - Unicode includes a massive range called PUA: the private use area. The codes in this range aren’t mapped to anything (and won’t be mapped to anything) and are for internal/custom use, not to be passed to external systems (for example, we use them in fish-shell to safely parse tokens into a string, turning an unescaped special character into just another Unicode code point in the string,…

I just tested and private use characters render as boxes for me (󰀀), the point here was to encode them in a way that they are hidden and treated as "part of" another character when copy/pasting.

Re: Smuggling arbitrary data through an emoji

#95

Post by dboreham »

palata wrote: post #47
HeikoBehrens wrote: post #14

FWIW, we considered this technique back at Pebble to make notifications more actionable and even filed a patent for that (sorry!) https://patents.justia.com/patent/9411785 Back then on iOS via ANCS, the watches wouldn't receive much more than the textual payload you'd see on the phone. We envisioned to be working with partners such as WhatsApp et al. to encode deep links/message ids into the message so one could resp…

Respectfully: how the hell would that be a valid patent? Feels like patenting the idea of writing text in white on white on a Word document such that you don't lose it but it doesn't get printed. It's just insane to ever call that "an invention".

Almost all filed patents are invalid.

Re: Smuggling arbitrary data through an emoji

#96

Post by frontporch »

you dont need 256 codepoints so you can neatly represent an octet (whatever that is), you just need 2 bits. you can just stack as many diacritical marks you want on any glyph. either the renderer allows practically unlimited or it allows 1/none. in either case that's a vuln. what would be really earth shattering is what i was hoping this article was: a way to just embed "; rm -rf ~/" into text without it being rendered. you also definitely dont need rust for this unless you want to exclude 90% of the programmer population.

Re: Smuggling arbitrary data through an emoji

#97

Post by jl6 »

tyho wrote: post #65
pava0 wrote: post #30

Earlier quoted context omitted.

For example?

A crude way: To watermark: First establish a keyed DRBG. For every nth token prediction: read a bit from the DRBG for every possible token to label them red/black. before selecting the next token, set the logit for black tokens to -Inf, this ensures a red token will be selected. To detect: Establish the same DRBG. Tokenize, for each nth token, determine the red set of tokens in that position. If you only see red toke…

It feels like this would only be feasible across longer passages of text, and some types of text may be less amenable to synonyms than others. For example, a tightly written mathematical proof versus a rambling essay. Biased token selection may be detectable in the latter (using a statistical test), and may cause the text to be irreparably broken in the former.

Re: Smuggling arbitrary data through an emoji

#98

Post by paulgb »

frontporch wrote: post #96

you dont need 256 codepoints so you can neatly represent an octet (whatever that is), you just need 2 bits. you can just stack as many diacritical marks you want on any glyph. either the renderer allows practically unlimited or it allows 1/none. in either case that's a vuln. what would be really earth shattering is what i was hoping this article was: a way to just embed "; rm -rf ~/" into text without it being render…

I think the Rust is more readable for bytemucking stuff than dynamic languages because the reader doesn't have to infer the byte widths, but for what it's worth the demo contains a TypeScript implementation: https://github.com/paulgb/emoji-encoder/blob/main/app/encodi...

Re: Smuggling arbitrary data through an emoji

#99

Post by palata »

neilv wrote: post #67
rwmj wrote: post #56

Earlier quoted context omitted.

Companies acquire indefensible patents all the time. They are used in bulk to threaten smaller competitors ("we've got 500 patents in this field, better not bring your product to market"). This is one reason why patents can be terrible for competition.

About 25 years ago, this was explained to me as "sword patents and shield patents". Sure, some can use patents as swords, to suppress legitimate competition, or to extract undue rents. But you can also use patents as shields, to protect in various ways against those swords. If I ran a BigTech (like the original warm-fuzzy Google reputation), I'd be registering any plausible patents, and have lawyers figure out how to…

> If I ran a BigTech

History tells us that those who run a BigTech become crazy narcissists serving their own interests :).

Re: Smuggling arbitrary data through an emoji

#100

Post by palata »

krupan wrote: post #63
palata wrote: post #47

Earlier quoted context omitted.

Respectfully: how the hell would that be a valid patent? Feels like patenting the idea of writing text in white on white on a Word document such that you don't lose it but it doesn't get printed. It's just insane to ever call that "an invention".

Patents are part of the game you have to play, like it or not. If you don't patent your inventions somebody else will and they will come after you with their lawyers. Patents are used defensively far more often than they are used offensively in these stupid "Intellectual Property" battles. Because of this, there is absolutely no point in shaming someone for patenting a thing, especially when they are apologetic about…

> Because of this, there is absolutely no point in shaming someone for patenting a thing

Well I wouldn't shame someone whose job was to patent something absurd. I was just saying that this is not an invention at all, and any system that protects that "innovation" is a broken system.

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