Prevent factory reset for short passwords in CryptKeeper

automerge: 8fca3fc

* commit '8fca3fcc06cfa7c4baf16b3bc53c4e52c9678fbb':
  Prevent factory reset for short passwords in CryptKeeper

src/com/android/settings/CryptKeeper.java

@@ -137,6 +137,17 @@ public class CryptKeeper extends Activity implements TextView.OnEditorActionList
     // how long we wait to clear a right pattern
     private static final int RIGHT_PATTERN_CLEAR_TIMEOUT_MS = 500;
 
+    // When the user enters a short pin/password, run this to show an error,
+    // but don't count it against attempts.
+    private final Runnable mFakeUnlockAttemptRunnable = new Runnable() {
+        public void run() {
+            handleBadAttempt(1 /* failedAttempt */);
+        }
+    };
+
+    // TODO: this should be tuned to match minimum decryption timeout
+    private static final int FAKE_ATTEMPT_DELAY = 1000;
+
     private Runnable mClearPatternRunnable = new Runnable() {
         public void run() {
             mLockPatternView.clearPattern();
@@ -200,6 +211,12 @@ public class CryptKeeper extends Activity implements TextView.OnEditorActionList
                 showFactoryReset(true);
                 return;
             } else {
+                handleBadAttempt(failedAttempts);
+            }
+        }
+    }
+
+    private void handleBadAttempt(Integer failedAttempts) {
         // Wrong entry. Handle pattern case.
         if (mLockPatternView != null) {
             mLockPatternView.setDisplayMode(DisplayMode.Wrong);
@@ -238,8 +255,6 @@ public class CryptKeeper extends Activity implements TextView.OnEditorActionList
             }
         }
     }
-        }
-    }
 
     private class ValidationTask extends AsyncTask<Void, Void, Boolean> {
         int state;
@@ -307,6 +322,8 @@ public class CryptKeeper extends Activity implements TextView.OnEditorActionList
             | StatusBarManager.DISABLE_SEARCH
             | StatusBarManager.DISABLE_RECENT;
 
+    protected static final int MIN_LENGTH_BEFORE_REPORT = LockPatternUtils.MIN_LOCK_PATTERN_SIZE;
+
     /** @return whether or not this Activity was started for debugging the UI only. */
     private boolean isDebugView() {
         return getIntent().hasExtra(EXTRA_FORCE_VIEW);
@@ -679,6 +696,10 @@ public class CryptKeeper extends Activity implements TextView.OnEditorActionList
         }
     }
 
+    private void fakeUnlockAttempt(View postingView) {
+        postingView.postDelayed(mFakeUnlockAttemptRunnable, FAKE_ATTEMPT_DELAY);
+    }
+
     protected LockPatternView.OnPatternListener mChooseNewLockPatternListener =
         new LockPatternView.OnPatternListener() {
 
@@ -694,7 +715,12 @@ public class CryptKeeper extends Activity implements TextView.OnEditorActionList
         @Override
         public void onPatternDetected(List<LockPatternView.Cell> pattern) {
             mLockPatternView.setEnabled(false);
+            if (pattern.size() >= MIN_LENGTH_BEFORE_REPORT) {
                 new DecryptTask().execute(LockPatternUtils.patternToString(pattern));
+            } else {
+                // Allow user to make as many of these as they want.
+                fakeUnlockAttempt(mLockPatternView);
+            }
         }
 
         @Override
@@ -851,8 +877,13 @@ public class CryptKeeper extends Activity implements TextView.OnEditorActionList
             mPasswordEntry.setEnabled(false);
             setBackFunctionality(false);
 
+            if (password.length() >= LockPatternUtils.MIN_LOCK_PATTERN_SIZE) {
                 Log.d(TAG, "Attempting to send command to decrypt");
                 new DecryptTask().execute(password);
+            } else {
+                // Allow user to make as many of these as they want.
+                fakeUnlockAttempt(mPasswordEntry);
+            }
 
             return true;
         }