From 1abc167b700576b5a78e2ea3dfd9899db509c10a Mon Sep 17 00:00:00 2001
From: Vojtech Novak <vonovak@gmail.com>
Date: Tue, 4 Sep 2018 13:55:37 +0200
Subject: [PATCH] extract a function, add null checks (#146)

* extract a function, add null checks

* rename function
---
 .../oblador/keychain/DeviceAvailability.java  |  6 ++--
 .../CipherStorageKeystoreAESCBC.java          | 35 ++++++++++---------
 2 files changed, 22 insertions(+), 19 deletions(-)

diff --git a/android/src/main/java/com/oblador/keychain/DeviceAvailability.java b/android/src/main/java/com/oblador/keychain/DeviceAvailability.java
index 508ad4f..090d47b 100644
--- a/android/src/main/java/com/oblador/keychain/DeviceAvailability.java
+++ b/android/src/main/java/com/oblador/keychain/DeviceAvailability.java
@@ -10,15 +10,15 @@ public class DeviceAvailability {
         if (android.os.Build.VERSION.SDK_INT >= 23) {
             FingerprintManager fingerprintManager =
                 (FingerprintManager) context.getSystemService(Context.FINGERPRINT_SERVICE);
-            return fingerprintManager.isHardwareDetected() &&
+            return fingerprintManager != null && fingerprintManager.isHardwareDetected() &&
                 fingerprintManager.hasEnrolledFingerprints();
         }
         return false;
     }
 
-    public static boolean isSecure(Context context) {
+    public static boolean isDeviceSecure(Context context) {
         KeyguardManager keyguardManager =
                 (KeyguardManager) context.getSystemService(Context.KEYGUARD_SERVICE);
-        return android.os.Build.VERSION.SDK_INT >= 23 && keyguardManager.isDeviceSecure();
+        return Build.VERSION.SDK_INT >= 23 && keyguardManager != null && keyguardManager.isDeviceSecure();
     }
 }
diff --git a/android/src/main/java/com/oblador/keychain/cipherStorage/CipherStorageKeystoreAESCBC.java b/android/src/main/java/com/oblador/keychain/cipherStorage/CipherStorageKeystoreAESCBC.java
index 8174ed9..40063dc 100644
--- a/android/src/main/java/com/oblador/keychain/cipherStorage/CipherStorageKeystoreAESCBC.java
+++ b/android/src/main/java/com/oblador/keychain/cipherStorage/CipherStorageKeystoreAESCBC.java
@@ -29,6 +29,7 @@ import javax.crypto.CipherOutputStream;
 import javax.crypto.KeyGenerator;
 import javax.crypto.spec.IvParameterSpec;
 
+@TargetApi(Build.VERSION_CODES.M)
 public class CipherStorageKeystoreAESCBC implements CipherStorage {
     public static final String CIPHER_STORAGE_NAME = "KeystoreAESCBC";
     public static final String DEFAULT_SERVICE = "RN_KEYCHAIN_DEFAULT_ALIAS";
@@ -52,7 +53,6 @@ public class CipherStorageKeystoreAESCBC implements CipherStorage {
         return Build.VERSION_CODES.M;
     }
 
-    @TargetApi(Build.VERSION_CODES.M)
     @Override
     public EncryptionResult encrypt(@NonNull String service, @NonNull String username, @NonNull String password) throws CryptoFailedException {
         service = getDefaultServiceIfEmpty(service);
@@ -61,21 +61,7 @@ public class CipherStorageKeystoreAESCBC implements CipherStorage {
             KeyStore keyStore = getKeyStoreAndLoad();
 
             if (!keyStore.containsAlias(service)) {
-                AlgorithmParameterSpec spec;
-                spec = new KeyGenParameterSpec.Builder(
-                        service,
-                        KeyProperties.PURPOSE_DECRYPT | KeyProperties.PURPOSE_ENCRYPT)
-                        .setBlockModes(ENCRYPTION_BLOCK_MODE)
-                        .setEncryptionPaddings(ENCRYPTION_PADDING)
-                        .setRandomizedEncryptionRequired(true)
-                        //.setUserAuthenticationRequired(true) // Will throw InvalidAlgorithmParameterException if there is no fingerprint enrolled on the device
-                        .setKeySize(ENCRYPTION_KEY_SIZE)
-                        .build();
-
-                KeyGenerator generator = KeyGenerator.getInstance(ENCRYPTION_ALGORITHM, KEYSTORE_TYPE);
-                generator.init(spec);
-
-                generator.generateKey();
+                generateKeyAndStoreUnderAlias(service);
             }
 
             Key key = keyStore.getKey(service, null);
@@ -93,6 +79,23 @@ public class CipherStorageKeystoreAESCBC implements CipherStorage {
         }
     }
 
+    private void generateKeyAndStoreUnderAlias(@NonNull String service) throws NoSuchAlgorithmException, NoSuchProviderException, InvalidAlgorithmParameterException {
+        AlgorithmParameterSpec spec = new KeyGenParameterSpec.Builder(
+                service,
+                KeyProperties.PURPOSE_DECRYPT | KeyProperties.PURPOSE_ENCRYPT)
+                .setBlockModes(ENCRYPTION_BLOCK_MODE)
+                .setEncryptionPaddings(ENCRYPTION_PADDING)
+                .setRandomizedEncryptionRequired(true)
+                //.setUserAuthenticationRequired(true) // Will throw InvalidAlgorithmParameterException if there is no fingerprint enrolled on the device
+                .setKeySize(ENCRYPTION_KEY_SIZE)
+                .build();
+
+        KeyGenerator generator = KeyGenerator.getInstance(ENCRYPTION_ALGORITHM, KEYSTORE_TYPE);
+        generator.init(spec);
+
+        generator.generateKey();
+    }
+
     @Override
     public DecryptionResult decrypt(@NonNull String service, @NonNull byte[] username, @NonNull byte[] password) throws CryptoFailedException {
         service = getDefaultServiceIfEmpty(service);