Make sure that external callers cannot pass in the confirm bypass extra

Security fix for vulnerability where an app could launch into the screen lock
change dialog without first confirming the existing password/pattern.

Also, make sure that the fragments are launched with the correct corresponding
activity.

Bug: 9858403
Change-Id: I0f2c00a44abeb624c6fba0497bf6036a6f1a4564

AndroidManifest.xml

@@ -959,7 +959,6 @@
 
         <!-- Second and third-level settings -->
 
-
         <!-- Lock screen settings -->
         <activity android:name="ConfirmLockPattern"/>
 
@@ -975,6 +974,11 @@
             </intent-filter>
         </activity>
 
+        <activity android:name="ChooseLockGeneric$InternalActivity" android:exported="false"
+            android:label="@string/lockpassword_choose_lock_generic_header"
+            android:excludeFromRecents="true"
+        />
+
         <activity android:name="ChooseLockPattern" android:exported="false"/>
 
         <activity android:name="ChooseLockPassword" android:exported="false"

src/com/android/settings/ChooseLockGeneric.java

@@ -45,6 +45,9 @@ public class ChooseLockGeneric extends PreferenceActivity {
         return modIntent;
     }
 
+    public static class InternalActivity extends ChooseLockGeneric {
+    }
+
     public static class ChooseLockGenericFragment extends SettingsPreferenceFragment {
         private static final int MIN_PASSWORD_LENGTH = 4;
         private static final String KEY_UNLOCK_BACKUP_INFO = "unlock_backup_info";
@@ -80,7 +83,9 @@ public class ChooseLockGeneric extends PreferenceActivity {
             // Defaults to needing to confirm credentials
             final boolean confirmCredentials = getActivity().getIntent()
                 .getBooleanExtra(CONFIRM_CREDENTIALS, true);
-            mPasswordConfirmed = !confirmCredentials;
+            if (getActivity() instanceof ChooseLockGeneric.InternalActivity) {
+                mPasswordConfirmed = !confirmCredentials;
+            }
 
             if (savedInstanceState != null) {
                 mPasswordConfirmed = savedInstanceState.getBoolean(PASSWORD_CONFIRMED);
@@ -303,7 +308,8 @@ public class ChooseLockGeneric extends PreferenceActivity {
         }
 
         private Intent getBiometricSensorIntent() {
-            Intent fallBackIntent = new Intent().setClass(getActivity(), ChooseLockGeneric.class);
+            Intent fallBackIntent = new Intent().setClass(getActivity(),
+                    ChooseLockGeneric.InternalActivity.class);
             fallBackIntent.putExtra(LockPatternUtils.LOCKSCREEN_BIOMETRIC_WEAK_FALLBACK, true);
             fallBackIntent.putExtra(CONFIRM_CREDENTIALS, false);
             fallBackIntent.putExtra(EXTRA_SHOW_FRAGMENT_TITLE,

src/com/android/settings/ChooseLockPassword.java

@@ -153,6 +153,9 @@ public class ChooseLockPassword extends PreferenceActivity {
             super.onCreate(savedInstanceState);
             mLockPatternUtils = new LockPatternUtils(getActivity());
             Intent intent = getActivity().getIntent();
+            if (!(getActivity() instanceof ChooseLockPassword)) {
+                throw new SecurityException("Fragment contained in wrong activity");
+            }
             mRequestedQuality = Math.max(intent.getIntExtra(LockPatternUtils.PASSWORD_TYPE_KEY,
                     mRequestedQuality), mLockPatternUtils.getRequestedPasswordQuality());
             mPasswordMinLength = Math.max(

src/com/android/settings/ChooseLockPattern.java

@@ -301,6 +301,9 @@ public class ChooseLockPattern extends PreferenceActivity {
         public void onCreate(Bundle savedInstanceState) {
             super.onCreate(savedInstanceState);
             mChooseLockSettingsHelper = new ChooseLockSettingsHelper(getActivity());
+            if (!(getActivity() instanceof ChooseLockPattern)) {
+                throw new SecurityException("Fragment contained in wrong activity");
+            }
         }
 
         @Override
@@ -331,7 +334,7 @@ public class ChooseLockPattern extends PreferenceActivity {
             topLayout.setDefaultTouchRecepient(mLockPatternView);
 
             final boolean confirmCredentials = getActivity().getIntent()
-                    .getBooleanExtra("confirm_credentials", false);
+                    .getBooleanExtra("confirm_credentials", true);
 
             if (savedInstanceState == null) {
                 if (confirmCredentials) {