Don't try to zero out sensitive memory

Perhaps revisit this later

app/src/main/java/me/impy/aegis/AuthActivity.java

@@ -93,7 +93,7 @@ public class AuthActivity extends AegisActivity implements FingerprintUiHelper.C
         button.setOnClickListener(new View.OnClickListener() {
             @Override
             public void onClick(View v) {
-                char[] password = AuthHelper.getPassword(_textPassword, true);
+                char[] password = AuthHelper.getEditTextChars(_textPassword);
                 trySlots(PasswordSlot.class, password);
             }
         });

app/src/main/java/me/impy/aegis/CustomAuthenticatedSlide.java

@@ -67,8 +67,7 @@ public class CustomAuthenticatedSlide extends Fragment implements FingerprintUiH
     }
 
     public char[] getPassword() {
-        AuthHelper.clearPassword(_textPasswordConfirm);
+        return AuthHelper.getEditTextChars(_textPassword);
-        return AuthHelper.getPassword(_textPassword, true);
     }
 
     public Cipher getFingerCipher() {

app/src/main/java/me/impy/aegis/DerivationTask.java

@@ -24,7 +24,6 @@ public class DerivationTask extends ProgressDialogTask<DerivationTask.Params, Se
         try {
             byte[] salt = CryptoUtils.generateSalt();
             SecretKey key = params.Slot.deriveKey(params.Password, salt, CryptoUtils.CRYPTO_SCRYPT_N, CryptoUtils.CRYPTO_SCRYPT_r, CryptoUtils.CRYPTO_SCRYPT_p);
-            CryptoUtils.zero(params.Password);
             return key;
         } catch (Exception e) {
             return null;

app/src/main/java/me/impy/aegis/EditProfileActivity.java

@@ -219,7 +219,6 @@ public class EditProfileActivity extends AegisActivity {
         try {
             char[] secret = AuthHelper.getEditTextChars(_textSecret);
             info.setSecret(secret);
-            CryptoUtils.zero(secret);
             info.setIssuer(_textIssuer.getText().toString());
             info.setPeriod(period);
             info.setDigits(digits);

app/src/main/java/me/impy/aegis/PasswordDialogFragment.java

@@ -43,9 +43,7 @@ public class PasswordDialogFragment extends SlotDialogFragment {
                     return;
                 }
 
-                AuthHelper.clearPassword(textPasswordConfirm);
+                char[] password = AuthHelper.getEditTextChars(textPassword);
-                char[] password = AuthHelper.getPassword(textPassword, true);
-
                 PasswordSlot slot = new PasswordSlot();
                 DerivationTask task = new DerivationTask(getContext(), key -> {
                     Cipher cipher;

app/src/main/java/me/impy/aegis/SlotCollectionTask.java

@@ -62,10 +62,6 @@ public class SlotCollectionTask<T extends Slot> extends ProgressDialogTask<SlotC
             return null;
         } catch (Exception e) {
             throw new UndeclaredThrowableException(e);
-        } finally {
-            if (params.Obj instanceof char[]) {
-                CryptoUtils.zero((char[]) params.Obj);
-            }
         }
     }
 

app/src/main/java/me/impy/aegis/crypto/CryptoUtils.java

@@ -44,10 +44,7 @@ public class CryptoUtils {
     public static SecretKey deriveKey(char[] password, byte[] salt, int n, int r, int p) throws NoSuchAlgorithmException, InvalidKeySpecException {
         byte[] bytes = toBytes(password);
         byte[] keyBytes = SCrypt.generate(bytes, salt, n, r, p, CRYPTO_KEY_SIZE);
-        zero(bytes);
+        return new SecretKeySpec(keyBytes, 0, keyBytes.length, "AES");
-        SecretKey key = new SecretKeySpec(keyBytes, 0, keyBytes.length, "AES");
-        zero(keyBytes);
-        return key;
     }
 
     public static Cipher createCipher(SecretKey key, int opmode) throws NoSuchPaddingException, NoSuchAlgorithmException, InvalidAlgorithmParameterException, InvalidKeyException {
@@ -102,7 +99,6 @@ public class CryptoUtils {
 
         byte[] bytes = key.getEncoded();
         hash.update(bytes);
-        CryptoUtils.zero(bytes);
         return hash.digest();
     }
 
@@ -127,14 +123,6 @@ public class CryptoUtils {
         return data;
     }
 
-    public static void zero(char[] data) {
-        Arrays.fill(data, '\0');
-    }
-
-    public static void zero(byte[] data) {
-        Arrays.fill(data, (byte) 0);
-    }
-
     private static byte[] toBytes(char[] chars) {
         CharBuffer charBuf = CharBuffer.wrap(chars);
         ByteBuffer byteBuf = Charset.forName("UTF-8").encode(charBuf);

app/src/main/java/me/impy/aegis/crypto/slots/Slot.java

@@ -33,16 +33,13 @@ public abstract class Slot implements Serializable {
     // getKey decrypts the encrypted master key in this slot with the given key and returns it.
     public SecretKey getKey(Cipher cipher) throws BadPaddingException, IllegalBlockSizeException {
         byte[] decryptedKeyBytes = cipher.doFinal(_encryptedMasterKey);
-        SecretKey decryptedKey = new SecretKeySpec(decryptedKeyBytes, CryptoUtils.CRYPTO_CIPHER_AEAD);
+        return new SecretKeySpec(decryptedKeyBytes, CryptoUtils.CRYPTO_CIPHER_AEAD);
-        CryptoUtils.zero(decryptedKeyBytes);
-        return decryptedKey;
     }
 
     // setKey encrypts the given master key with the given key and stores the result in this slot.
     public void setKey(MasterKey masterKey, Cipher cipher) throws BadPaddingException, IllegalBlockSizeException {
         byte[] masterKeyBytes = masterKey.getBytes();
         _encryptedMasterKey = cipher.doFinal(masterKeyBytes);
-        CryptoUtils.zero(masterKeyBytes);
     }
 
     // suppress the AES ECB warning

app/src/main/java/me/impy/aegis/encoding/Base32.java

@@ -87,9 +87,7 @@ public class Base32 {
             base32[j++] = base32Chars.charAt(digit);
         }
 
-        char[] res = Arrays.copyOf(base32, j);
+        return Arrays.copyOf(base32, j);
-        CryptoUtils.zero(base32);
-        return res;
     }
 
     /**

app/src/main/java/me/impy/aegis/helpers/AuthHelper.java

@@ -11,15 +11,7 @@ public class AuthHelper {
     private AuthHelper() {
     }
 
-    public static char[] getPassword(EditText text, boolean clear) {
+    public static void clearEditText(EditText text) {
-        char[] password = getEditTextChars(text);
-        if (clear) {
-            clearPassword(text);
-        }
-        return password;
-    }
-
-    public static void clearPassword(EditText text) {
         text.getText().clear();
     }
 
@@ -33,9 +25,6 @@ public class AuthHelper {
     public static boolean arePasswordsEqual(EditText text1, EditText text2) {
         char[] password = getEditTextChars(text1);
         char[] passwordConfirm = getEditTextChars(text2);
-        boolean equal = password.length != 0 && Arrays.equals(password, passwordConfirm);
+        return password.length != 0 && Arrays.equals(password, passwordConfirm);
-        CryptoUtils.zero(password);
-        CryptoUtils.zero(passwordConfirm);
-        return equal;
     }
 }