Android Keystore？.getKey在某些设备上返回null
我在我的应用程序中实施指纹认证。 我面临的问题是在某些设备上无法正常工作，而我的应用程序崩溃。 不过，它也适用于某些设备。 问题是在这一行
val key = keyStore?.getKey(Constants.FINGERPRINT_KEY_NAME, null) as SecretKey LogCat说：
11-02 14:27:42.825 E: FATAL EXCEPTION: main Process: kyivenergo.ua.kyivenegro, PID: 2298 java.lang.RuntimeException: Unable to start activity ComponentInfo{kyivenergo.ua.kyivenegro/ua.dtec.appOk.ui.screens.splash.SplashScreenActivity}: kotlin.TypeCastException: null cannot be cast to non-null type javax.crypto.SecretKey at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2646) at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2707) at android.app.ActivityThread.-wrap12(ActivityThread.java) at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1460) at android.os.Handler.dispatchMessage(Handler.java:102) at android.os.Looper.loop(Looper.java:154) at android.app.ActivityThread.main(ActivityThread.java:6077) at java.lang.reflect.Method.invoke(Native Method) at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:866) at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:756) Caused by: kotlin.TypeCastException: null cannot be cast to non-null type javax.crypto.SecretKey at ua.dtec.appOk.ui.dialog.FingerprintDialog.initCipher(FingerprintDialog.kt:222) at ua.dtec.appOk.ui.dialog.FingerprintDialog.doCheck(FingerprintDialog.kt:147) at ua.dtec.appOk.ui.dialog.FingerprintDialog.show(FingerprintDialog.kt:65) at ua.dtec.appOk.ui.screens.splash.SplashScreenActivity.showFingerprintDialog(SplashScreenActivity.kt:55) at ua.dtec.appOk.ui.screens.splash.SplashScreenActivity.onStart(SplashScreenActivity.kt:33) at android.app.Instrumentation.callActivityOnStart(Instrumentation.java:1248) at android.app.Activity.performStart(Activity.java:6679) at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2609) at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2707) at android.app.ActivityThread.-wrap12(ActivityThread.java) at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1460) at android.os.Handler.dispatchMessage(Handler.java:102) at android.os.Looper.loop(Looper.java:154) at android.app.ActivityThread.main(ActivityThread.java:6077) at java.lang.reflect.Method.invoke(Native Method) at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:866) at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:756)
这是我的完整代码：
private fun doCheck() { if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) { keyguardManager = c.getSystemService(KEYGUARD_SERVICE) as KeyguardManager fingerprintManager = c.getSystemService(FINGERPRINT_SERVICE) as FingerprintManager if (!fingerprintManager!!.isHardwareDetected()) { Toast.makeText(c, R.string.dialog_fingerprint_no_hardware_toast, Toast.LENGTH_SHORT).show() } if (ActivityCompat.checkSelfPermission(c, Manifest.permission.USE_FINGERPRINT) != PackageManager.PERMISSION_GRANTED) { Toast.makeText(c, R.string.dialog_fingerprint_enable_fingerprint_permission, Toast.LENGTH_SHORT).show() } if (!fingerprintManager!!.hasEnrolledFingerprints()) { Toast.makeText(c, R.string.dialog_fingerprint_no_fingerprints, Toast.LENGTH_SHORT).show() } if (!keyguardManager?.isKeyguardSecure()!!) { Toast.makeText(c, R.string.dialog_fingerprint_no_lock_screen, Toast.LENGTH_SHORT).show() } else { generateKey() } if (initCipher()) { cryptoObject = FingerprintManager.CryptoObject(cipher) helper = FingerPrintHelper(dialog!!) helper?.FingerprintHandler(c) helper?.startAuth(fingerprintManager!!, cryptoObject!!) } } } private fun generateKey() { try { keyStore = KeyStore.getInstance("AndroidKeyStore") if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) { keyGenerator = KeyGenerator.getInstance(KeyProperties.KEY_ALGORITHM_AES, "AndroidKeyStore") keyStore?.load(null) keyGenerator!!.init( KeyGenParameterSpec.Builder(Constants.FINGERPRINT_KEY_NAME, KeyProperties.PURPOSE_ENCRYPT or KeyProperties.PURPOSE_DECRYPT) .setBlockModes(KeyProperties.BLOCK_MODE_CBC) .setUserAuthenticationRequired(true) .setEncryptionPaddings( KeyProperties.ENCRYPTION_PADDING_PKCS7) .build()) } keyGenerator?.generateKey() } catch (exc: KeyStoreException) { exc.printStackTrace() throw FingerprintException(exc) } catch (exc: NoSuchAlgorithmException) { exc.printStackTrace() throw FingerprintException(exc) } catch (exc: NoSuchProviderException) { exc.printStackTrace() throw FingerprintException(exc) } catch (exc: InvalidAlgorithmParameterException) { exc.printStackTrace() throw FingerprintException(exc) } catch (exc: CertificateException) { exc.printStackTrace() throw FingerprintException(exc) } catch (exc: IOException) { exc.printStackTrace() throw FingerprintException(exc) } } @RequiresApi(Build.VERSION_CODES.M) fun initCipher(): Boolean { try { cipher = Cipher.getInstance( KeyProperties.KEY_ALGORITHM_AES + "/" + KeyProperties.BLOCK_MODE_CBC + "/" + KeyProperties.ENCRYPTION_PADDING_PKCS7) } catch (e: NoSuchAlgorithmException) { throw RuntimeException("Failed to get Cipher", e) } catch (e: NoSuchPaddingException) { throw RuntimeException("Failed to get Cipher", e) } try { keyStore?.load( null) val key = keyStore?.getKey(Constants.FINGERPRINT_KEY_NAME, null) as SecretKey cipher?.init(Cipher.ENCRYPT_MODE, key) return true } catch (e: KeyPermanentlyInvalidatedException) { return false } catch (e: KeyStoreException) { throw RuntimeException("Failed to init Cipher", e) } catch (e: CertificateException) { throw RuntimeException("Failed to init Cipher", e) } catch (e: UnrecoverableKeyException) { throw RuntimeException("Failed to init Cipher", e) } catch (e: IOException) { throw RuntimeException("Failed to init Cipher", e) } catch (e: NoSuchAlgorithmException) { throw RuntimeException("Failed to init Cipher", e) } catch (e: InvalidKeyException) { throw RuntimeException("Failed to init Cipher", e) } }
建立版本应该比棉花糖更大或相等。 如果你尝试少于M，那么它可能会引发错误。
您将null设置为不可空的SecretKey
val key = keyStore?.getKey(Constants.FINGERPRINT_KEY_NAME, null) as SecretKey
如果keyStore为null或getKey()返回null（如果给定的别名不存在或不标识与键相关的条目），则可以在此处获得null。
所以在那里得到空值是完全正确的。 既然你是向上的，你甚至可能遇到一个ClassCastException 。 为了防止这只是使用类型安全的铸造操作符as? 代替。
val key: SecretKey? = keyStore?.getKey(Constants.FINGERPRINT_KEY_NAME, null) as? SecretKey