Files
app_Settings/src/com/android/settings/nfc/PaymentDefaultDialog.java
Andres Morales 78ce5e8c9f Prevent newlines and long captions selecting default payment app
This would allow attackers to spoof the default selection
dialog causing the user to unkowingly change their default
payment handler.

Bug: 15906632
Change-Id: I49ad2a7351bd6d2c1f9a79ad9be0cbc9787ca6c3
2014-08-07 00:45:03 +00:00

144 lines
5.0 KiB
Java

/*
* Copyright (C) 2013 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.android.settings.nfc;
import android.content.ComponentName;
import android.content.DialogInterface;
import android.content.Intent;
import android.nfc.cardemulation.CardEmulation;
import android.os.Bundle;
import android.util.Log;
import com.android.internal.app.AlertActivity;
import com.android.internal.app.AlertController;
import com.android.settings.R;
import com.android.settings.nfc.PaymentBackend.PaymentAppInfo;
import java.util.List;
public final class PaymentDefaultDialog extends AlertActivity implements
DialogInterface.OnClickListener {
public static final String TAG = "PaymentDefaultDialog";
private static final int PAYMENT_APP_MAX_CAPTION_LENGTH = 40;
private PaymentBackend mBackend;
private ComponentName mNewDefault;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
mBackend = new PaymentBackend(this);
Intent intent = getIntent();
ComponentName component = intent.getParcelableExtra(
CardEmulation.EXTRA_SERVICE_COMPONENT);
String category = intent.getStringExtra(CardEmulation.EXTRA_CATEGORY);
setResult(RESULT_CANCELED);
if (!buildDialog(component, category)) {
finish();
}
}
@Override
public void onClick(DialogInterface dialog, int which) {
switch (which) {
case BUTTON_POSITIVE:
mBackend.setDefaultPaymentApp(mNewDefault);
setResult(RESULT_OK);
break;
case BUTTON_NEGATIVE:
break;
}
}
private boolean buildDialog(ComponentName component, String category) {
if (component == null || category == null) {
Log.e(TAG, "Component or category are null");
return false;
}
if (!CardEmulation.CATEGORY_PAYMENT.equals(category)) {
Log.e(TAG, "Don't support defaults for category " + category);
return false;
}
// Check if passed in service exists
PaymentAppInfo requestedPaymentApp = null;
PaymentAppInfo defaultPaymentApp = null;
List<PaymentAppInfo> services = mBackend.getPaymentAppInfos();
for (PaymentAppInfo service : services) {
if (component.equals(service.componentName)) {
requestedPaymentApp = service;
}
if (service.isDefault) {
defaultPaymentApp = service;
}
}
if (requestedPaymentApp == null) {
Log.e(TAG, "Component " + component + " is not a registered payment service.");
return false;
}
// Get current mode and default component
ComponentName defaultComponent = mBackend.getDefaultPaymentApp();
if (defaultComponent != null && defaultComponent.equals(component)) {
Log.e(TAG, "Component " + component + " is already default.");
return false;
}
mNewDefault = component;
// Compose dialog; get
final AlertController.AlertParams p = mAlertParams;
p.mTitle = getString(R.string.nfc_payment_set_default_label);
if (defaultPaymentApp == null) {
String formatString = getString(R.string.nfc_payment_set_default);
String msg = String.format(formatString,
sanitizePaymentAppCaption(requestedPaymentApp.caption.toString()));
p.mMessage = msg;
} else {
String formatString = getString(R.string.nfc_payment_set_default_instead_of);
String msg = String.format(formatString,
sanitizePaymentAppCaption(requestedPaymentApp.caption.toString()),
sanitizePaymentAppCaption(defaultPaymentApp.caption.toString()));
p.mMessage = msg;
}
p.mPositiveButtonText = getString(R.string.yes);
p.mNegativeButtonText = getString(R.string.no);
p.mPositiveButtonListener = this;
p.mNegativeButtonListener = this;
setupAlert();
return true;
}
private String sanitizePaymentAppCaption(String input) {
String sanitizedString = input.replace('\n', ' ').replace('\r', ' ').trim();
if (sanitizedString.length() > PAYMENT_APP_MAX_CAPTION_LENGTH) {
return sanitizedString.substring(0, PAYMENT_APP_MAX_CAPTION_LENGTH);
}
return sanitizedString;
}
}