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.impl; 019 020 021import java.util.Collections; 022import java.util.HashSet; 023import java.util.LinkedHashSet; 024import java.util.Set; 025 026import com.nimbusds.jose.JOSEException; 027import com.nimbusds.jose.JWSAlgorithm; 028 029 030/** 031 * The base abstract class for Elliptic Curve Digital Signature Algorithm 032 * (ECDSA) signers and validators of {@link com.nimbusds.jose.JWSObject JWS 033 * objects}. 034 * 035 * <p>Supports the following algorithms: 036 * 037 * <ul> 038 * <li>{@link com.nimbusds.jose.JWSAlgorithm#ES256} 039 * <li>{@link com.nimbusds.jose.JWSAlgorithm#ES256K} 040 * <li>{@link com.nimbusds.jose.JWSAlgorithm#ES384} 041 * <li>{@link com.nimbusds.jose.JWSAlgorithm#ES512} 042 * </ul> 043 * 044 * @author Axel Nennker 045 * @author Vladimir Dzhuvinov 046 * @version 2017-05-13 047 */ 048public abstract class ECDSAProvider extends BaseJWSProvider { 049 050 051 /** 052 * The supported JWS algorithms by the EC-DSA provider class. 053 */ 054 public static final Set<JWSAlgorithm> SUPPORTED_ALGORITHMS; 055 056 057 static { 058 Set<JWSAlgorithm> algs = new LinkedHashSet<>(); 059 algs.add(JWSAlgorithm.ES256); 060 algs.add(JWSAlgorithm.ES256K); 061 algs.add(JWSAlgorithm.ES384); 062 algs.add(JWSAlgorithm.ES512); 063 SUPPORTED_ALGORITHMS = Collections.unmodifiableSet(algs); 064 } 065 066 067 /** 068 * Creates a new Elliptic Curve Digital Signature Algorithm (ECDSA) 069 * provider. 070 * 071 * @param alg The EC-DSA algorithm. Must be supported and not 072 * {@code null}. 073 * 074 * @throws JOSEException If JWS algorithm is not supported. 075 */ 076 protected ECDSAProvider(final JWSAlgorithm alg) 077 throws JOSEException { 078 079 super(new HashSet<>(Collections.singletonList(alg))); 080 081 if (! SUPPORTED_ALGORITHMS.contains(alg)) { 082 throw new JOSEException("Unsupported EC DSA algorithm: " + alg); 083 } 084 } 085 086 087 /** 088 * Returns the supported ECDSA algorithm. 089 * 090 * @see #supportedJWSAlgorithms() 091 * 092 * @return The supported ECDSA algorithm. 093 */ 094 public JWSAlgorithm supportedECDSAAlgorithm() { 095 096 return supportedJWSAlgorithms().iterator().next(); 097 } 098} 099