001/*
002 * nimbus-jose-jwt
003 *
004 * Copyright 2012-2016, Connect2id Ltd.
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.proc;
019
020
021import java.security.Key;
022import java.util.List;
023
024import com.nimbusds.jose.JWSHeader;
025import com.nimbusds.jose.KeySourceException;
026
027
028/**
029 * Interface for selecting key candidates for verifying a JSON Web Signature
030 * (JWS) object. Applications should utilise this interface or a similar
031 * framework to determine whether a received JWS object (or signed JWT) is
032 * eligible for {@link com.nimbusds.jose.JWSVerifier verification} and further
033 * processing.
034 *
035 * <p>The key selection should be based on application specific criteria, such
036 * as recognised header parameters referencing the key (e.g. {@code kid},
037 * {@code x5t}) and / or the JWS object {@link SecurityContext}.
038 *
039 * <p>See JSON Web Signature (JWS), Appendix D. Notes on Key Selection for
040 * suggestions.
041 *
042 * <p>Possible key types:
043 *
044 * <ul>
045 *     <li>{@link javax.crypto.SecretKey} for HMAC keys.
046 *     <li>{@link java.security.interfaces.RSAPublicKey} public RSA keys.
047 *     <li>{@link java.security.interfaces.ECPublicKey} public EC keys.
048 * </ul>
049 *
050 * @author Vladimir Dzhuvinov
051 * @version 2016-06-21
052 */
053public interface JWSKeySelector<C extends SecurityContext>  {
054
055
056        /**
057         * Selects key candidates for verifying a JWS object.
058         *
059         * @param header  The header of the JWS object. Must not be
060         *                {@code null}.
061         * @param context Optional context of the JWS object, {@code null} if
062         *                not required.
063         *
064         * @return The key candidates in trial order, empty list if none.
065         *
066         * @throws KeySourceException If a key sourcing exception is
067         *                            encountered, e.g. on remote JWK
068         *                            retrieval.
069         */
070        List<? extends Key> selectJWSKeys(final JWSHeader header, final C context)
071                throws KeySourceException;
072}