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Android wallpaper images can threaten privacy

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Re: Android wallpaper images can threaten privacy

#61

Post by qwerty456127 »

jeroenhd wrote: post #7

Although this is an interesting, novel method, there are so many fingerprinting capable APIs in native code that I don't think this matters much. Many apps I use daily require internal storage permissions and a bunch of them drop random dotfiles with magical IDs in there. Xiaomi even dumps a world readable unique device ID on the emulated SD card. Not all apps require external storage permissions, but even then there…

> Many apps I use daily require internal storage permissions and a bunch of them drop random dotfiles with magical IDs in there.

Why can't these apps be restricted to certain folders you need them to access?

I also feel like apps which abuse file system permissions to modify the user file system (e.g. create files useless to the user), let alone the system file system should be reported and banned.

Any app should have full rights to write anything to a special directory dedicated for it however. But you can set up a script to purge it or delete specific files from it on a schedule.

Re: Android wallpaper images can threaten privacy

#63

Post by mPReDiToR »

qwerty456127 wrote: post #61
jeroenhd wrote: post #7

Although this is an interesting, novel method, there are so many fingerprinting capable APIs in native code that I don't think this matters much. Many apps I use daily require internal storage permissions and a bunch of them drop random dotfiles with magical IDs in there. Xiaomi even dumps a world readable unique device ID on the emulated SD card. Not all apps require external storage permissions, but even then there…

> Many apps I use daily require internal storage permissions and a bunch of them drop random dotfiles with magical IDs in there. Why can't these apps be restricted to certain folders you need them to access? I also feel like apps which abuse file system permissions to modify the user file system (e.g. create files useless to the user), let alone the system file system should be reported and banned. Any app should hav…

Isn't this policy how Termux was neutered?

Re: Android wallpaper images can threaten privacy

#64

Post by jeroenhd »

qwerty456127 wrote: post #61
jeroenhd wrote: post #7

Although this is an interesting, novel method, there are so many fingerprinting capable APIs in native code that I don't think this matters much. Many apps I use daily require internal storage permissions and a bunch of them drop random dotfiles with magical IDs in there. Xiaomi even dumps a world readable unique device ID on the emulated SD card. Not all apps require external storage permissions, but even then there…

> Many apps I use daily require internal storage permissions and a bunch of them drop random dotfiles with magical IDs in there. Why can't these apps be restricted to certain folders you need them to access? I also feel like apps which abuse file system permissions to modify the user file system (e.g. create files useless to the user), let alone the system file system should be reported and banned. Any app should hav…

Google is working on that with scoped storage, but a lot of old code doesn't work with that yet and dropping the API would break tons of apps. They've been trying to kill general external storage for this reason since Android 4.4, but every time there's huge blowback from users and developers because "they're trying to take our file explorers" or whatever.

In KDE Connect you already need to use the modern API to pick a location for file browsing and it works fine. I picked the entire virtual storage area and that's what's available through remote browsing, but I could've picked a single directory. If all apps supported this, we'd be a lot better off.

Of course, there's a perverse incentive to put off the transition as long as possible so that stalking libraries can make more money. I think Google is moving very closely to forcing the new API with the release of Android 12, which would mean that most app developers can't really put off updating much longer.

Re: Android wallpaper images can threaten privacy

#65

Post by ohgodplsno »

mikeiz404 wrote: post #44
jeroenhd wrote: post #7

Although this is an interesting, novel method, there are so many fingerprinting capable APIs in native code that I don't think this matters much. Many apps I use daily require internal storage permissions and a bunch of them drop random dotfiles with magical IDs in there. Xiaomi even dumps a world readable unique device ID on the emulated SD card. Not all apps require external storage permissions, but even then there…

Not saying this would be easy but another approach would be to use references to the colors instead of the actual colors. Other color related APIs would have to be updated to accept the references or, if you wanted to add more flexibility, compound color manipulation operations. It would be the responsibility of the renderer, which I am assuming is protected as I am not familiar at all with android, to compute the fi…

Android's theming system does not have the ability to dynamically re-set IDs. And, assuming they managed to do so and keep the reference unaccessible to users (because then you could just do context.getColor(android.R.color.material_you_color_primary) to resolve it), you can still access it through reflection.

Re: Android wallpaper images can threaten privacy

#66

Post by ohgodplsno »

jasonjayr wrote: post #49
jeroenhd wrote: post #7

Although this is an interesting, novel method, there are so many fingerprinting capable APIs in native code that I don't think this matters much. Many apps I use daily require internal storage permissions and a bunch of them drop random dotfiles with magical IDs in there. Xiaomi even dumps a world readable unique device ID on the emulated SD card. Not all apps require external storage permissions, but even then there…

Chasing this dragon is exhausting, and seems to be requiring more user-hostile measures that prevent end users from using their device fully. Can there be a legal frame work where Google and Apple just take your source code and builds it on their farm, and app review is a source-code level review? And Developers that refuse to do these things are just blocked from developing on these platforms?

Handing over your signing keys, your IP, to a company that cannot even be arsed to review apps properly? What could go wrong?

Re: Android wallpaper images can threaten privacy

#67

Post by iggldiggl »

jeroenhd wrote: post #64
qwerty456127 wrote: post #61

Earlier quoted context omitted.

> Many apps I use daily require internal storage permissions and a bunch of them drop random dotfiles with magical IDs in there. Why can't these apps be restricted to certain folders you need them to access? I also feel like apps which abuse file system permissions to modify the user file system (e.g. create files useless to the user), let alone the system file system should be reported and banned. Any app should hav…

Google is working on that with scoped storage, but a lot of old code doesn't work with that yet and dropping the API would break tons of apps. They've been trying to kill general external storage for this reason since Android 4.4, but every time there's huge blowback from users and developers because "they're trying to take our file explorers" or whatever. In KDE Connect you already need to use the modern API to pick…

They could have made the transition much more straightforward by just making the permissions system more granular (i.e. let the user pick a directory instead of simply asking storage access yes/no) and leaving the existing file APIs intact otherwise, just throw a permission error if you're accessing anything outside of the granted scope.

Instead they tried to force through a completely new API that isn't compatible with anything that came beforehand, isn't compatible with code that must have a classic file handle and cannot easily be changed (native libraries, parts of the Android API itself), introduces exciting new bugs and has worse performance.

Plus at the same time they seem hellbent on hiding the true, original location of files on the file system, so a) if an app needs to ensure continuing access to a file, it needs to copy it to its own storage (Yay, dozens of copies of the same file) b) this breaks any usages and file formats that don't consist of a single, atomic, fully standalone file (HTML files, playlists, subtitles, multi-part archives, ...).

Re: Android wallpaper images can threaten privacy

#68

Post by pas »

hilbert42 wrote: post #54

I'm beginning to feel as if after I'd put my Android phone though a metal shredder that the individual remaining atoms will somehow still have my ID on them à la QM's conservation of information. It's been clear to me for quite some while that the whole notion of trying to achieve privacy on the internet is broken - the paradigm we're now using (and have always been using) to achieve privacy is wrong. As no matter wh…

It's simple information theory (or basic OPSEC). Every kind of customization, every differing behavior reduces entropy. That's why Tor recommends using the browser with a fixed size window and with default settings. (Of course neither simple nor basic means easy.)

Re: Android wallpaper images can threaten privacy

#69

Post by hansel_der »

magicalist wrote: post #53
ignoramous wrote: post #40

Earlier quoted context omitted.

See: https://grapheneos.org/usage#sandboxed-play-services

Ah, I see, thanks. I thought you meant like gmail, not play services.

i would be kind of surprised if the gmail-app didn't have more access than other email clients

Re: Android wallpaper images can threaten privacy

#70

Post by Daniel_sk »

refulgentis wrote: post #41
MrDresden wrote: post #25

Earlier quoted context omitted.

Android dev here. Still have the same default wallpaper as my Pixel 3 came with 3 years ago.

That wallpaper would have the same 3 colors as many, many, other people. The problem here arises when your wallpaper is unique, no?

You can still use as input along with other parts that are accessible without any permissions - for example the android version, device name, IP address...
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