4 ms·

Easier said than done. Well, it means they have to keep track of every build, and keep every version of every OS live, and that's not something they really do.

Easier said than done. Well, it means they have to keep track of every build, and keep every version of every OS live, and that's not something they really do. Especially in cases of security fixes, they'll take down an old version from the update servers. As for 15min, they're actually testing fast patching right now, although it's currently limited to security updates (rapid response).

saurik 3y ago
FWIW, I do think they might have changed things very recently--but only for some legal argument (maybe as a result of Corellium...) as opposed to any technical one--but they really did just leave every single variant of every single update on their server... I even made a tool for jailbroken iOS devices that would get the original update files from Apple's servers and implemented exactly this idea: it would checksum every file against the copy from the bill of materials in the update and was able to download only the files that were different (by carving them out of the remote zip file using HTTP Range requests).
- parker_mountain 3y ago
  I really hope you're not relying on that, because it's not every original variant ;) although probably most of them are.
viraptor 3y ago
> it means they have to keep track of every build, and keep every version of every OS live That's not a lot of work. I would be extremely surprised if they were not already doing it. If someone reports an issue going back to a specific version, they need to be able to install that specific one. I think you're overestimating the effort / underestimating Apple resources here. Ubuntu keeps all released packages, going back to 2004 online for example. (And isos, even for the effectively dead powerpc) Microsoft's symbol server is likely also a way bigger project than just preserving images of all versions. > and that's not something they really do Are you actually speaking for Apple engineering here? The version not being advertised on the update servers does not mean it's not available. Also, there's the question of supply chain audit. I doubt their security would accept not being able to say "this is/isn't what we shipped at the time".

saurik 3y ago

FWIW, I do think they might have changed things very recently--but only for some legal argument (maybe as a result of Corellium...) as opposed to any technical one--but they really did just leave every single variant of every single update on their server... I even made a tool for jailbroken iOS devices that would get the original update files from Apple's servers and implemented exactly this idea: it would checksum every file against the copy from the bill of materials in the update and was able to download only the files that were different (by carving them out of the remote zip file using HTTP Range requests).

parker_mountain 3y ago
I really hope you're not relying on that, because it's not every original variant ;) although probably most of them are.

viraptor 3y ago

> it means they have to keep track of every build, and keep every version of every OS live That's not a lot of work. I would be extremely surprised if they were not already doing it. If someone reports an issue going back to a specific version, they need to be able to install that specific one. I think you're overestimating the effort / underestimating Apple resources here. Ubuntu keeps all released packages, going back to 2004 online for example. (And isos, even for the effectively dead powerpc) Microsoft's symbol server is likely also a way bigger project than just preserving images of all versions. > and that's not something they really do Are you actually speaking for Apple engineering here? The version not being advertised on the update servers does not mean it's not available. Also, there's the question of supply chain audit. I doubt their security would accept not being able to say "this is/isn't what we shipped at the time".