On iOS 9, my app is prompting user for Touch ID authentication before using Private key (saved on Secure Enclave, protected by Biometrics) to sign data. But SecKeyRawSign is returning incorrect status (AUTH FAILED) when user locks the device (without any attempt to autheticate) while Touch ID prompt is displayed. It should be SYSTEM CANCELLED analogus to LAContext.evaluatePolicy error message. This seems to be defect in SecKeyRawSign implementation. Anyone else seen this issue?
Issue can be reproduced using Apple's Keychain Touch ID example.
https://developer.apple.com/library/ios/samplecode/KeychainTouchID/Introduction/Intro.html