react-native-keychain: Huawei Android 7.0 java.lang.NullPointerException

Thanks for the hard work on this package!

I’m not sure this is an issue with this library, but I wanted to document it in case others are also experiencing it (it looks similar to https://github.com/iamMehedi/Secured-Preference-Store/issues/25).

When uploading our app to the Google Play store, google’s pre-launch report indicates that the app is crashing with a null pointer exception (see stack trace at bottom). On launch our app (abbreviated) calls:

  createStoreSecret = () => Keychain
    .setGenericPassword('user', 'password')
    .then(() => {
      // success
    })

  Keychain
    .getGenericPassword()
    .then((credentials) => {
      if (credentials) {
        // success
      } else {
        createStoreSecret();
      }
    }).catch(() => {
      createStoreSecret();
    });

Should we not do this?

Using version 2.0.0-rc of this package.

Environment:
  OS: macOS Sierra 10.12.6
  Node: 6.9.5
  Yarn: Not Found
  npm: 3.10.10
  Watchman: 4.7.0
  Xcode: Xcode 9.1 Build version 9B55
  Android Studio: Not Found

Packages: (wanted => installed)
  react: 16.0.0
  react-native: 0.51.1

Stacktrace:

java.lang.NullPointerException: Attempt to invoke interface method 'int android.security.IKeystoreService.del(java.lang.String, int)' on a null object reference
	at android.security.KeyStore.delete(KeyStore.java:186)
	at android.security.Credentials.deletePrivateKeyTypeForAlias(Credentials.java:292)
	at android.security.Credentials.deleteAllTypesForAlias(Credentials.java:251)
	at android.security.keystore.AndroidKeyStoreKeyGeneratorSpi.engineGenerateKey(AndroidKeyStoreKeyGeneratorSpi.java:329)
	at javax.crypto.KeyGenerator.generateKey(KeyGenerator.java:580)
	at com.oblador.keychain.cipherStorage.CipherStorageKeystoreAESCBC.encrypt(CipherStorageKeystoreAESCBC.java:78)
	at com.oblador.keychain.KeychainModule.setGenericPasswordForOptions(KeychainModule.java:65)
	at java.lang.reflect.Method.invoke(Native Method)
	at com.facebook.react.bridge.JavaMethodWrapper.invoke(JavaMethodWrapper.java:374)
	at com.facebook.react.bridge.JavaModuleWrapper.invoke(JavaModuleWrapper.java:162)
	at com.facebook.react.bridge.queue.NativeRunnable.run(Native Method)
	at android.os.Handler.handleCallback(Handler.java:755)
	at android.os.Handler.dispatchMessage(Handler.java:95)
	at com.facebook.react.bridge.queue.MessageQueueThreadHandler.dispatchMessage(MessageQueueThreadHandler.java:31)
	at android.os.Looper.loop(Looper.java:156)
	at com.facebook.react.bridge.queue.MessageQueueThreadImpl$3.run(MessageQueueThreadImpl.java:194)
	at java.lang.Thread.run(Thread.java:776)