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Shouldn't the reviewer check every update? What if the "minor" update contains some rule breaking changes? They can't know/assume from the developer's update de

Shouldn't the reviewer check every update? What if the "minor" update contains some rule breaking changes? They can't know/assume from the developer's update description that it is a minor update, and don't have much other information about what has changed. Otherwise it would be very easy to first publish a "normal" app, and then just publish an update with bad stuff added.

deleted 6y ago
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simonh 6y ago
They do review every update, but they have a lot of automated tools that help a lot when reviewing minor changes. So for example, if only a few bytes have changed and the binary is only a few bytes different in size they can mostly rely on the tools. That’s probably most bug fix updates right there.
- gregoriol 6y ago
  Automated tools will probably check private api usage and maybe some basic technical stuff, but they won't be able to catch a feature change. And even if you were right, changing some text or url would pass your test as only a few characters change, but that could make a big difference regarding the feature.
- _qulr 6y ago
  > So for example, if only a few bytes have changed and the binary is only a few bytes different in size they can mostly rely on the tools. That's not how compiled optimized binaries work, especially not with Apple platforms, ever-changing Xcode and Swift compiler versions, etc. Have you tried comparing the binaries of minor app updates? (I just tried comparing the binaries of my own app updates, where I have the source code and know what changed, but it's not pretty, and not "a few bytes".) Moreover, App Store reviewers are not the least bit qualified to even make this determination with regard to "bytes changed". Two binaries aren't even going to have the same load address for the __TEXT __text segment, and thus a lot of stuff will be different. You think App Store reviewers have any conception of the structure of a Mach-O? Now, one might try to hand-wave and say the "automated tools" will take care of everything, but that's extremely unlikely. Diffing binaries is a skill that requires a human with extensive experience in reverse engineering. If it were totally automated, then all of the securities researchers out there would have those tools too, but they don't. There are of course tools that help a lot, but the human researcher is still essential to the process.
  - faeyanpiraat 6y ago
    I assume Apple has access to the source code of the app, so they probably are not comparing binary blobs for changes.
    - _qulr 6y ago
      > I assume Apple has access to the source code of the app No, Apple doesn't get our source code. Why would you assume that?
    - gregoriol 6y ago
      They don't: you submit a compiled binary for review
      - dagmx 6y ago
        Sort of. You submit either a binary blob or LLVM IR. The latter is great because Apple can do the final platform specific compile for you, and build out for new systems as needed.
        saagarjha 6y ago
        Well, to some extent. LLVM IR isn’t magic, and Apple doesn’t really change much.
    - faeyanpiraat 6y ago
      I don't get the downvotes. They are making the compiler. How hard can it be to do a proper decompiler? They have the binary; they have the source (in some way)
      - saagarjha 6y ago
        Very hard. Like, this is the holy grail of security/reverse engineering.
      - colejohnson66 6y ago

deleted 6y ago

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simonh 6y ago

They do review every update, but they have a lot of automated tools that help a lot when reviewing minor changes. So for example, if only a few bytes have changed and the binary is only a few bytes different in size they can mostly rely on the tools. That’s probably most bug fix updates right there.

gregoriol 6y ago
Automated tools will probably check private api usage and maybe some basic technical stuff, but they won't be able to catch a feature change. And even if you were right, changing some text or url would pass your test as only a few characters change, but that could make a big difference regarding the feature.
_qulr 6y ago
> So for example, if only a few bytes have changed and the binary is only a few bytes different in size they can mostly rely on the tools. That's not how compiled optimized binaries work, especially not with Apple platforms, ever-changing Xcode and Swift compiler versions, etc. Have you tried comparing the binaries of minor app updates? (I just tried comparing the binaries of my own app updates, where I have the source code and know what changed, but it's not pretty, and not "a few bytes".) Moreover, App Store reviewers are not the least bit qualified to even make this determination with regard to "bytes changed". Two binaries aren't even going to have the same load address for the __TEXT __text segment, and thus a lot of stuff will be different. You think App Store reviewers have any conception of the structure of a Mach-O? Now, one might try to hand-wave and say the "automated tools" will take care of everything, but that's extremely unlikely. Diffing binaries is a skill that requires a human with extensive experience in reverse engineering. If it were totally automated, then all of the securities researchers out there would have those tools too, but they don't. There are of course tools that help a lot, but the human researcher is still essential to the process.
- faeyanpiraat 6y ago
  I assume Apple has access to the source code of the app, so they probably are not comparing binary blobs for changes.
  - _qulr 6y ago
    > I assume Apple has access to the source code of the app No, Apple doesn't get our source code. Why would you assume that?
  - gregoriol 6y ago
    They don't: you submit a compiled binary for review
    - dagmx 6y ago
      Sort of. You submit either a binary blob or LLVM IR. The latter is great because Apple can do the final platform specific compile for you, and build out for new systems as needed.
      - saagarjha 6y ago
        Well, to some extent. LLVM IR isn’t magic, and Apple doesn’t really change much.
  - faeyanpiraat 6y ago
    I don't get the downvotes. They are making the compiler. How hard can it be to do a proper decompiler? They have the binary; they have the source (in some way)
    - saagarjha 6y ago
      Very hard. Like, this is the holy grail of security/reverse engineering.
    - colejohnson66 6y ago