Derive passwords on a separate thread in the intro

Also, show a progress dialog while waiting

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

@@ -101,14 +101,6 @@ public class AuthActivity extends AppCompatActivity implements FingerprintUiHelp
         builder.create().show();
     }
 
-    /*DerivationTask task = new DerivationTask(this);
-    DerivationTask.Params params = new DerivationTask.Params() {{
-        Slots = _slots;
-        Slot = (PasswordSlot) slot;
-        Password = AuthHelper.getPassword(_textPassword, true);
-    }};
-    masterKey = task.execute(params).get();*/
-
     private <T extends Slot> void trySlots(Class<T> type, Object obj) {
         new SlotCollectionTask<T>(type, this, this).execute(new SlotCollectionTask.Params(){{
             Slots = _slots;

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

@@ -22,10 +22,7 @@ import java.lang.reflect.UndeclaredThrowableException;
 import javax.crypto.Cipher;
 import javax.crypto.SecretKey;
 
-import me.impy.aegis.crypto.CryptoUtils;
 import me.impy.aegis.crypto.KeyStoreHandle;
-import me.impy.aegis.crypto.slots.FingerprintSlot;
-import me.impy.aegis.crypto.slots.PasswordSlot;
 import me.impy.aegis.crypto.slots.Slot;
 import me.impy.aegis.finger.FingerprintUiHelper;
 import me.impy.aegis.helpers.AuthHelper;
@@ -60,18 +57,12 @@ public class CustomAuthenticatedSlide extends Fragment implements FingerprintUiH
         return _cryptType;
     }
 
-    public Cipher getCipher(Slot slot) throws Exception {
-        if (slot instanceof PasswordSlot) {
-            char[] password = AuthHelper.getPassword(_textPassword, true);
-            byte[] salt = CryptoUtils.generateSalt();
-            SecretKey key = ((PasswordSlot)slot).deriveKey(password, salt, CryptoUtils.CRYPTO_SCRYPT_N, CryptoUtils.CRYPTO_SCRYPT_r, CryptoUtils.CRYPTO_SCRYPT_p);
-            CryptoUtils.zero(password);
-            return Slot.createCipher(key, Cipher.ENCRYPT_MODE);
-        } else if (slot instanceof FingerprintSlot) {
-            return _fingerCipher;
-        } else {
-            throw new RuntimeException();
-        }
+    public char[] getPassword() {
+        return AuthHelper.getPassword(_textPassword, true);
+    }
+
+    public Cipher getFingerCipher() {
+        return _fingerCipher;
     }
 
     public void setBgColor(int color) {

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

@@ -0,0 +1,57 @@
+package me.impy.aegis;
+
+import android.app.ProgressDialog;
+import android.content.Context;
+import android.os.AsyncTask;
+
+import javax.crypto.SecretKey;
+
+import me.impy.aegis.crypto.CryptoUtils;
+import me.impy.aegis.crypto.slots.PasswordSlot;
+
+public class DerivationTask extends AsyncTask<DerivationTask.Params, Void, SecretKey> {
+    private Callback _cb;
+    private ProgressDialog _dialog;
+
+    public DerivationTask(Context context, Callback cb) {
+        _cb = cb;
+        _dialog = new ProgressDialog(context);
+        _dialog.setCancelable(false);
+    }
+
+    @Override
+    protected SecretKey doInBackground(DerivationTask.Params... args) {
+        DerivationTask.Params params = args[0];
+        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;
+        }
+    }
+
+    @Override
+    protected void onPreExecute() {
+        _dialog.setMessage("Deriving key from password");
+        _dialog.show();
+    }
+
+    @Override
+    protected void onPostExecute(SecretKey key) {
+        if (_dialog.isShowing()) {
+            _dialog.dismiss();
+        }
+        _cb.onTaskFinished(key);
+    }
+
+    static class Params {
+        public PasswordSlot Slot;
+        public char[] Password;
+    }
+
+    interface Callback {
+        void onTaskFinished(SecretKey key);
+    }
+}

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

@@ -12,16 +12,19 @@ import com.github.paolorotolo.appintro.AppIntroFragment;
 import com.github.paolorotolo.appintro.model.SliderPage;
 
 import javax.crypto.Cipher;
+import javax.crypto.SecretKey;
 
 import me.impy.aegis.crypto.CryptResult;
+import me.impy.aegis.crypto.CryptoUtils;
 import me.impy.aegis.crypto.MasterKey;
 import me.impy.aegis.crypto.slots.FingerprintSlot;
 import me.impy.aegis.crypto.slots.PasswordSlot;
+import me.impy.aegis.crypto.slots.Slot;
 import me.impy.aegis.crypto.slots.SlotCollection;
 import me.impy.aegis.db.Database;
 import me.impy.aegis.db.DatabaseFile;
 
-public class IntroActivity extends AppIntro {
+public class IntroActivity extends AppIntro implements DerivationTask.Callback {
     public static final int RESULT_OK = 0;
     public static final int RESULT_EXCEPTION = 1;
 
@@ -29,6 +32,11 @@ public class IntroActivity extends AppIntro {
     private CustomAuthenticationSlide _authenticationSlide;
     private Fragment _endSlide;
 
+    private Database _database;
+    private DatabaseFile _databaseFile;
+    private PasswordSlot _passwordSlot;
+    private Cipher _passwordCipher;
+
     @Override
     protected void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
@@ -65,6 +73,10 @@ public class IntroActivity extends AppIntro {
         endSliderPage.setBgColor(getResources().getColor(R.color.colorPrimary));
         _endSlide = AppIntroFragment.newInstance(endSliderPage);
         addSlide(_endSlide);
+
+        // create the database and database file
+        _database = new Database();
+        _databaseFile = new DatabaseFile();
     }
 
     private void setException(Exception e) {
@@ -76,10 +88,17 @@ public class IntroActivity extends AppIntro {
 
     @Override
     public void onSlideChanged(Fragment oldFragment, Fragment newFragment) {
-        // skip to the last slide if no encryption will be used
-        if (oldFragment == _authenticationSlide && newFragment != _endSlide) {
-            Intent intent = getIntent();
-            int cryptType = intent.getIntExtra("cryptType", CustomAuthenticationSlide.CRYPT_TYPE_INVALID);
+        Intent intent = getIntent();
+        int cryptType = intent.getIntExtra("cryptType", CustomAuthenticationSlide.CRYPT_TYPE_INVALID);
+
+        if (newFragment == _endSlide && cryptType != CustomAuthenticationSlide.CRYPT_TYPE_NONE) {
+            _passwordSlot = new PasswordSlot();
+            new DerivationTask(this, this).execute(new DerivationTask.Params() {{
+                Slot = _passwordSlot;
+                Password = _authenticatedSlide.getPassword();
+            }});
+        } else if (oldFragment == _authenticationSlide && newFragment != _endSlide) {
+            // skip to the last slide if no encryption will be used
             if (cryptType == CustomAuthenticationSlide.CRYPT_TYPE_NONE) {
                 // TODO: no magic indices
                 getPager().setCurrentItem(5);
@@ -91,10 +110,6 @@ public class IntroActivity extends AppIntro {
     public void onDonePressed(Fragment currentFragment) {
         super.onDonePressed(currentFragment);
 
-        // create the database and database file
-        Database database = new Database();
-        DatabaseFile databaseFile = new DatabaseFile();
-
         int cryptType = _authenticatedSlide.getCryptType();
 
         // generate the master key
@@ -108,15 +123,20 @@ public class IntroActivity extends AppIntro {
             }
         }
 
-        SlotCollection slots = databaseFile.getSlots();
+        SlotCollection slots = _databaseFile.getSlots();
         if (cryptType != CustomAuthenticationSlide.CRYPT_TYPE_NONE) {
             try {
                 // encrypt the master key with a key derived from the user's password
                 // and add it to the list of slots
-                PasswordSlot slot = new PasswordSlot();
-                Cipher cipher = _authenticatedSlide.getCipher(slot);
-                slots.encrypt(slot, masterKey, cipher);
-                slots.add(slot);
+                if (_passwordSlot == null || _passwordCipher == null) {
+                    throw new RuntimeException();
+                }
+                try {
+                    slots.encrypt(_passwordSlot, masterKey, _passwordCipher);
+                    slots.add(_passwordSlot);
+                } catch (Exception e) {
+                    setException(e);
+                }
             } catch (Exception e) {
                 setException(e);
                 return;
@@ -128,7 +148,7 @@ public class IntroActivity extends AppIntro {
                 // encrypt the master key with the fingerprint key
                 // and add it to the list of slots
                 FingerprintSlot slot = new FingerprintSlot();
-                Cipher cipher = _authenticatedSlide.getCipher(slot);
+                Cipher cipher = _authenticatedSlide.getFingerCipher();
                 slots.encrypt(slot, masterKey, cipher);
                 slots.add(slot);
             } catch (Exception e) {
@@ -139,15 +159,15 @@ public class IntroActivity extends AppIntro {
 
         // finally, save the database
         try {
-            byte[] bytes = database.serialize();
+            byte[] bytes = _database.serialize();
             if (cryptType == CustomAuthenticationSlide.CRYPT_TYPE_NONE) {
-                databaseFile.setContent(bytes);
+                _databaseFile.setContent(bytes);
             } else {
                 CryptResult result = masterKey.encrypt(bytes);
-                databaseFile.setContent(result.Data);
-                databaseFile.setCryptParameters(result.Parameters);
+                _databaseFile.setContent(result.Data);
+                _databaseFile.setCryptParameters(result.Parameters);
             }
-            databaseFile.save(getApplicationContext());
+            _databaseFile.save(getApplicationContext());
         } catch (Exception e) {
             setException(e);
             return;
@@ -163,4 +183,17 @@ public class IntroActivity extends AppIntro {
         prefs.edit().putBoolean("passedIntro", true).apply();
         finish();
     }
+
+    @Override
+    public void onTaskFinished(SecretKey key) {
+        if (key != null) {
+            try {
+                _passwordCipher = Slot.createCipher(key, Cipher.ENCRYPT_MODE);
+            } catch (Exception e) {
+                setException(e);
+            }
+        } else {
+            setException(new NullPointerException());
+        }
+    }
 }