Recent iOS, Mac app crashes linked to botched FairPlay DRM

iOS and OS X users are experiencing crashes due to corrupted binaries pushed out by Apple's servers over the Fourth of July holiday, according to Instapaper developer Marco Arment. The problem appears to be linked to Apple's FairPlay DRM scheme, which is added to apps downloaded via the iOS App Store or Mac App Store. While Apple appears to be working to correct the issue, the problem is ongoing as of Thursday.

Arment discovered the problem late Tuesday night after pushing an update to his Instapaper app to the App Store. "I was deluged by support e-mail and Twitter messages from customers saying that it crashed immediately on launch, even with a clean install," Arment wrote on his blog.

The problem appears to be caused by the addition of FairPlay DRM after the updated binary is submitted to Apple for distribution. An error in encoding the DRM causes the binary to become corrupt, causing the affected app to immediately crash on launch. Error logs point to a failure in the "AppleFairplayTextCrypterSession::fairplayOpen()" function, the first step in running any app distributed via the App Store or Mac App Store.

According to Arment's research, users are affected in some regions, but not others. Apple appears to be attempting to fix the problem on a case-by-case basis, as later downloads of the same Instapaper update function normally. However, developers that have submitted updates on July 3, 4, or 5 may still be affected by the problem.

"I'll repeat my warning to developers: if you can help it, do not release app updates today," Arment said via Twitter. "The corruption is widespread and ongoing."

Unfortunately for developers, users assume the problem is shoddy coding and are leaving negative reviews on affected apps. If you're getting update notices via the App Store or Mac App Store, it may be wise to hold off on updating until Apple can sort the problem out.

Apple was not able to respond to our request for comment on Thursday regarding the cause of the problem, or when a permanent fix might be in place.