iOS enable NX bit (runtime protection)

Question

Created Jul ’19

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How do I enable the XCode compiler to generate NX bit protected code?

A client has requested that I re-compile their app with this protection enabled. However, after reading the Security Document:

https://www.apple.com/business/site/docs/iOS_Security_Guide.pdf (section: "Runtime process security" starting on page 26)

I was under the impression that the NX bit security is enabled by default.

Is it possible to optionallly compile with NX bit security enabled? if so, how?

thanks,

|K<

Answered by DTS Engineer in 371597022

iOS never allows an app to execute from writeable memory. You do not need to specifically enable the ‘NX bit’ because it’s always enabled for all third-party code.

Share and Enjoy
—
Quinn “The Eskimo!”
Apple Developer Relations, Developer Technical Support, Core OS/Hardware

let myEmail = "eskimo" + "1" + "@apple.com"

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Answer 1

DTS Engineer OP

Apple

Jul ’19

Accepted Answer

iOS never allows an app to execute from writeable memory. You do not need to specifically enable the ‘NX bit’ because it’s always enabled for all third-party code.

Share and Enjoy
—
Quinn “The Eskimo!”
Apple Developer Relations, Developer Technical Support, Core OS/Hardware

let myEmail = "eskimo" + "1" + "@apple.com"

0

Answer 2

AvaloqKent OP

Jul ’19

Hi Quinn,

Thank you so very much.

Your continued diligence and dependable response time is totally appreciated.

thanks and regards from Switzerland,

|K<

0