001/* 002 * nimbus-jose-jwt 003 * 004 * Copyright 2012-2016, Connect2id Ltd and contributors. 005 * 006 * Licensed under the Apache License, Version 2.0 (the "License"); you may not use 007 * this file except in compliance with the License. You may obtain a copy of the 008 * License at 009 * 010 * http://www.apache.org/licenses/LICENSE-2.0 011 * 012 * Unless required by applicable law or agreed to in writing, software distributed 013 * under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR 014 * CONDITIONS OF ANY KIND, either express or implied. See the License for the 015 * specific language governing permissions and limitations under the License. 016 */ 017 018package com.nimbusds.jose.crypto.opts; 019 020 021import net.jcip.annotations.Immutable; 022 023import com.nimbusds.jose.JWSSignerOption; 024 025 026/** 027 * JSON Web Signature (JWS) option to prompt the user to authenticate in order 028 * to complete the signing operation. Android applications can use this option 029 * to trigger a biometric prompt that is required to unlock a private key 030 * created with {@code setUserAuthenticationRequired(true)}. 031 */ 032@Immutable 033public final class UserAuthenticationRequired implements JWSSignerOption { 034 035 036 private static final UserAuthenticationRequired SINGLETON = new UserAuthenticationRequired(); 037 038 039 /** 040 * Returns an instance of this class. 041 * 042 * @return The instance. 043 */ 044 public static UserAuthenticationRequired getInstance() { 045 return SINGLETON; 046 } 047 048 049 private UserAuthenticationRequired() { 050 } 051 052 053 @Override 054 public String toString() { 055 return "UserAuthenticationRequired"; 056 } 057}