5 ms·

Isn't it possible for a rooted device to fake beeing a non-rooted device to (selected) applications? To my understanding root means having the full control but

Isn't it possible for a rooted device to fake beeing a non-rooted device to (selected) applications? To my understanding root means having the full control but I fear that this definition doesn't apply to smartphones.

dsacco 9y ago
Yes. It's an arms race. To detect root, apps will try something like attempt to call su. If you're rooted and don't want the app to detect it, you can jail the app and prevent it from being able to detect it. Note that this is in theory. Almost all apps will implement root/jailbreak detection using the same crappy method, just like almost all of them use the same crappy method to detect if e.g. cert pinning is active. But some will use a very clever method that is not widely known and not well-documented. While it's true you can theoretically defeat any of these checks, in practice it (like most of reverse engineering) can be made incredible complex and difficult. For example, Facebook/Instagram have (as of the last time I checked) a complex custom system for checking if cert pinning has been bypassed, such that you can't just return-void the checks very easily.
swiley 9y ago
You still don't always have control over the kernel, although most of the time you can if you want.
bubblethink 9y ago
I think all these are stopgap measures until proper hardware DRM comes of age.
- panzer_wyrm 9y ago
  So we should lobby for legislation that stops hardware drm in its tracks. Or makes it comply with society interests.
  - bubblethink 9y ago
    That's not very realistic. Besides, the technology that would enable something like hardware DRM also has some legitimate uses in security. The same tech can ensure that your banking app isn't compromised even if the OS itself is compromised.
    - panzer_wyrm 9y ago
      A law that mandates that code signing can be done only by the owner solves that beautifully. As a bonus it kills walled gardens.
chickenbane 9y ago
Obviously I don't know the implementation details of how Netflix is detecting rooted devices, but my guess is they're using Play Services's new "GMS Certification". This involves using signed hardware that helps determine if the execution environment is trusted. So, users can still root the device, but Android + Play Services can still determine if features (such as DRM) can be relied on. It makes sense for Google to develop these features, especially as it wants to move Android to new devices (Cars?), reduce risk for mobile payments, in addition to giving stronger security features to content distributors. This also lets Android devices compete with security features like Apple's secure enclave. Honestly, if you are going to root your device you must accept you are not using it in the supported way the vendor intends. Therefore, you should not expect all the features of the supported configuration. I think that's a fair trade-off. Rooting your device is awesome!
- zAy0LfpBZLC8mAC 9y ago
  So ... because the vendor doesn't support you modifying something that you bought from them, it's also ok that they then intenionally break it? I'm not sure I am following ...
  - dsacco 9y ago
    If they put it in their TOS, sure.
    - zAy0LfpBZLC8mAC 9y ago
      The question was not whether it is be legal, but whether it is acceptable. Being an asshole is also legal, but it's still not OK to be an asshole.
      - dsacco 9y ago
        Oh, I understand what you mean. I thought you were speaking in the legal context. Mea culpa!
- 9y ago
Markoff 9y ago
yes, the keyword you are looking for is Magisk though it's not really for ordinary users

dsacco 9y ago

Yes. It's an arms race. To detect root, apps will try something like attempt to call su. If you're rooted and don't want the app to detect it, you can jail the app and prevent it from being able to detect it. Note that this is in theory. Almost all apps will implement root/jailbreak detection using the same crappy method, just like almost all of them use the same crappy method to detect if e.g. cert pinning is active. But some will use a very clever method that is not widely known and not well-documented. While it's true you can theoretically defeat any of these checks, in practice it (like most of reverse engineering) can be made incredible complex and difficult. For example, Facebook/Instagram have (as of the last time I checked) a complex custom system for checking if cert pinning has been bypassed, such that you can't just return-void the checks very easily.

swiley 9y ago

You still don't always have control over the kernel, although most of the time you can if you want.

bubblethink 9y ago

I think all these are stopgap measures until proper hardware DRM comes of age.

panzer_wyrm 9y ago
So we should lobby for legislation that stops hardware drm in its tracks. Or makes it comply with society interests.
- bubblethink 9y ago
  That's not very realistic. Besides, the technology that would enable something like hardware DRM also has some legitimate uses in security. The same tech can ensure that your banking app isn't compromised even if the OS itself is compromised.
  - panzer_wyrm 9y ago
    A law that mandates that code signing can be done only by the owner solves that beautifully. As a bonus it kills walled gardens.

chickenbane 9y ago

Obviously I don't know the implementation details of how Netflix is detecting rooted devices, but my guess is they're using Play Services's new "GMS Certification". This involves using signed hardware that helps determine if the execution environment is trusted. So, users can still root the device, but Android + Play Services can still determine if features (such as DRM) can be relied on. It makes sense for Google to develop these features, especially as it wants to move Android to new devices (Cars?), reduce risk for mobile payments, in addition to giving stronger security features to content distributors. This also lets Android devices compete with security features like Apple's secure enclave. Honestly, if you are going to root your device you must accept you are not using it in the supported way the vendor intends. Therefore, you should not expect all the features of the supported configuration. I think that's a fair trade-off. Rooting your device is awesome!

zAy0LfpBZLC8mAC 9y ago
So ... because the vendor doesn't support you modifying something that you bought from them, it's also ok that they then intenionally break it? I'm not sure I am following ...
- dsacco 9y ago
  If they put it in their TOS, sure.
  - zAy0LfpBZLC8mAC 9y ago
    The question was not whether it is be legal, but whether it is acceptable. Being an asshole is also legal, but it's still not OK to be an asshole.
    - dsacco 9y ago
      Oh, I understand what you mean. I thought you were speaking in the legal context. Mea culpa!
9y ago

Markoff 9y ago

yes, the keyword you are looking for is Magisk though it's not really for ordinary users