Refactor passwords/pins/patterns to byte[]

Relating to frameworks/base

Bug: 120484642
Test: manual - test setting and unlocking passwords/pins/patterns.
      automated - about 20 failing due to an issue in the test code.

Change-Id: I57aa530ca2db1a026c56b66f5b4c91172f2667f6
diff --git a/services/tests/servicestests/src/com/android/server/locksettings/MockSyntheticPasswordManager.java b/services/tests/servicestests/src/com/android/server/locksettings/MockSyntheticPasswordManager.java
index 6f68179..b9cb730 100644
--- a/services/tests/servicestests/src/com/android/server/locksettings/MockSyntheticPasswordManager.java
+++ b/services/tests/servicestests/src/com/android/server/locksettings/MockSyntheticPasswordManager.java
@@ -93,9 +93,13 @@
     }
 
     @Override
-    protected byte[] scrypt(String password, byte[] salt, int N, int r, int p, int outLen) {
+    protected byte[] scrypt(byte[] password, byte[] salt, int n, int r, int p, int outLen) {
         try {
-            PBEKeySpec spec = new PBEKeySpec(password.toCharArray(), salt, 10, outLen * 8);
+            char[] passwordChars = new char[password.length];
+            for (int i = 0; i < password.length; i++) {
+                passwordChars[i] = (char) password[i];
+            }
+            PBEKeySpec spec = new PBEKeySpec(passwordChars, salt, 10, outLen * 8);
             SecretKeyFactory f = SecretKeyFactory.getInstance("PBKDF2WithHmacSHA1");
             return f.generateSecret(spec).getEncoded();
         } catch (InvalidKeySpecException | NoSuchAlgorithmException e) {