4 ms·

They should pay Gruber more then to keep him from publicizing the issue at all. That aside, if Apple's sandboxing of the OS is solid, I don't see how a JIT wou

They should pay Gruber more then to keep him from publicizing the issue at all. That aside, if Apple's sandboxing of the OS is solid, I don't see how a JIT would be problematic.

easton 2y ago
There have been bugs that allowed you to do crazy things because of Safari’s JIT before (to the point they added a switch to the OS to disable it). Maybe they figure if Apple can’t write a safe one nobody else can either?
- JKCalhoun 2y ago
  I should think proper sandboxing of the rest of the OS should contain the mayhem to the process/container though. I think most of us on HN understand that "safety" is something you just have to accept is never 100%. As an example a team responsible for security can test the standard image libraries (libjpeg, etc.) using file-fuzzing to find any bugs around buffer overflows, etc. It's good they do this but we all know that this is still a statistical shot in the dark that may still leave a vector somewhere in the framework.
  - admax88qqq 2y ago
    I am fairly confident that the JIT restriction is about preventing third party browser engines (chrome) from running on the iPhone, not about security. When Google looked like they were investing heavily in PWAs they could have become a threat to native apps
    - jgruber 2y ago
      Apple’s BrowserEngineKit allows for the use of JITs. I have a link to the docs in my article.
- jgruber 2y ago
  Correct. If you enable Lockdown Mode, the JavaScript JIT compiler is disable by default in WebKit: https://support.apple.com/en-us/105120 https://support.apple.com/en-us/105120 So Apple considers its own trusted JIT a security threat surface.
pilif 2y ago
The problem is that a JIT implies that you can load arbitrary binary code into memory and execute it. This means that your app can load arbitrary updates from the server and execute them, for example based on some purchase not made in the AppStore. This is all about keeping the 30% tax and only tangentially about security.
- madeofpalk 2y ago
  Well, it's about bypassing App Review and other static security analysis, undocumented apis, etc. I think there's a fairly strong case here that it's about more than just protecting revenue (which it is also!)
  - pilif 2y ago
    Given the sandboxing and the security architecture of iOS, my conjecture is that apps could be perfectly safe even in light of the use of undocumented APIs (calls to which can be and are obfuscated even in today's setup) and accidental security flaws (which can and still do exist even in today's setup).

They should pay Gruber more then to keep him from publicizing the issue at all. That aside, if Apple's sandboxing of the OS is solid, I don't see how a JIT would be problematic.

easton 2y ago

There have been bugs that allowed you to do crazy things because of Safari’s JIT before (to the point they added a switch to the OS to disable it). Maybe they figure if Apple can’t write a safe one nobody else can either?

JKCalhoun 2y ago
I should think proper sandboxing of the rest of the OS should contain the mayhem to the process/container though. I think most of us on HN understand that "safety" is something you just have to accept is never 100%. As an example a team responsible for security can test the standard image libraries (libjpeg, etc.) using file-fuzzing to find any bugs around buffer overflows, etc. It's good they do this but we all know that this is still a statistical shot in the dark that may still leave a vector somewhere in the framework.
- admax88qqq 2y ago
  I am fairly confident that the JIT restriction is about preventing third party browser engines (chrome) from running on the iPhone, not about security. When Google looked like they were investing heavily in PWAs they could have become a threat to native apps
  - jgruber 2y ago
    Apple’s BrowserEngineKit allows for the use of JITs. I have a link to the docs in my article.
jgruber 2y ago
Correct. If you enable Lockdown Mode, the JavaScript JIT compiler is disable by default in WebKit: https://support.apple.com/en-us/105120 https://support.apple.com/en-us/105120 So Apple considers its own trusted JIT a security threat surface.

pilif 2y ago

The problem is that a JIT implies that you can load arbitrary binary code into memory and execute it. This means that your app can load arbitrary updates from the server and execute them, for example based on some purchase not made in the AppStore. This is all about keeping the 30% tax and only tangentially about security.

madeofpalk 2y ago
Well, it's about bypassing App Review and other static security analysis, undocumented apis, etc. I think there's a fairly strong case here that it's about more than just protecting revenue (which it is also!)
- pilif 2y ago
  Given the sandboxing and the security architecture of iOS, my conjecture is that apps could be perfectly safe even in light of the use of undocumented APIs (calls to which can be and are obfuscated even in today's setup) and accidental security flaws (which can and still do exist even in today's setup).