The release of iOS 15 is coming, and with it Apple has again strengthened the security of the platform. Among the improvements, iOS 15 requires an updated code signature format. The code signature assures end users that the app is coming from a known and approved source and has not been modified or tampered with. While the code signature format is new, iOS has always required code signing.

In the iOS 14.2 beta 2, Apple introduced a new more secure signature format and began warning users who try to launch an app signed with the old signature format.

With iOS 15 Apple takes an even stricter stance – the signature format has been updated again and become mandatory. Apps using older signature formats cannot be installed or launched. This includes some apps that ran without warning on iOS 14. In order to run on iOS 15 these apps will have to be re-signed.

The good news is that this improvement does not require any changes from developers distributing their apps through the App Store or TestFlight because App Store Connect will re-sign the app.

Ivanti customers distributing their apps though the Apple Developer Enterprise Program and using incapptic Connect don’t need to worry either. Starting with version 1.38.0 their apps can be re-signed automatically to conform with iOS 15 requirements.

Other developers using ad hoc, or enterprise distribution might need to re-sign their apps manually and should check if their apps need to be re-signed using the codesign utility as outlined here

Learn more about how Ivanti incapptic Connect simplifies, secures, and automates the app release process, allowing business units to focus on changing user needs and creating innovative new apps rather than performing tedious metadata management.

References:

https://developer.apple.com/forums/thread/682775#681438022

https://developer.apple.com/documentation/xcode/using-the-latest-code-signature-format

https://support.apple.com/guide/security/welcome/web