001package com.nimbusds.oauth2.sdk.auth;
002
003
004import net.jcip.annotations.Immutable;
005
006import com.nimbusds.oauth2.sdk.id.Identifier;
007
008
009/**
010 * Client authentication method at the Token endpoint. This class is immutable.
011 *
012 * <p>Constants are provided for four client authentication methods:
013 *
014 * <ul>
015 *     <li>{@link #CLIENT_SECRET_BASIC} (default)
016 *     <li>{@link #CLIENT_SECRET_POST}
017 *     <li>{@link #CLIENT_SECRET_JWT}
018 *     <li>{@link #PRIVATE_KEY_JWT}
019 * </ul>
020 *
021 * <p>Use the constructor to define a custom client authentication method.
022 *
023 * <p>Related specifications:
024 *
025 * <ul>
026 *     <li>OAuth 2.0 (RFC 6749), section 2.3.
027 * </ul>
028 *
029 * @author Vladimir Dzhuvinov
030 */
031@Immutable
032public final class ClientAuthenticationMethod extends Identifier {
033
034
035        /**
036         * Clients that have received a client secret from the authorisation 
037         * server authenticate with the authorisation server in accordance with
038         * section 3.2.1 of OAuth 2.0 using HTTP Basic authentication. This is 
039         * the default if no method has been registered for the client.
040         */
041        public static final ClientAuthenticationMethod CLIENT_SECRET_BASIC = 
042                new ClientAuthenticationMethod("client_secret_basic");
043
044
045        /**
046         * Clients that have received a client secret from the authorisation 
047         * server authenticate with the authorisation server in accordance with
048         * section 3.2.1 of OAuth 2.0 by including the client credentials in 
049         * the request body.
050         */
051        public static final ClientAuthenticationMethod CLIENT_SECRET_POST =
052                new ClientAuthenticationMethod("client_secret_post");
053
054
055        /**
056         * Clients that have received a client secret from the authorisation 
057         * server, create a JWT using an HMAC SHA algorithm, such as HMAC 
058         * SHA-256. The HMAC (Hash-based Message Authentication Code) is
059         * calculated using the value of client secret as the shared key. The 
060         * client authenticates in accordance with section 2.2 of (JWT) Bearer
061         * Token Profiles and OAuth 2.0 Assertion Profile. 
062         */
063        public static final ClientAuthenticationMethod CLIENT_SECRET_JWT =
064                new ClientAuthenticationMethod("client_secret_jwt");
065
066
067        /**
068         * Clients that have registered a public key sign a JWT using the RSA 
069         * algorithm if a RSA key was registered or the ECDSA algorithm if an 
070         * Elliptic Curve key was registered (see JWA for the algorithm 
071         * identifiers). The client authenticates in accordance with section 
072         * 2.2 of (JWT) Bearer Token Profiles and OAuth 2.0 Assertion Profile.
073         */
074        public static final ClientAuthenticationMethod PRIVATE_KEY_JWT =
075                new ClientAuthenticationMethod("private_key_jwt");
076
077
078        /**
079         * Gets the default client authentication method.
080         *
081         * @return {@link #CLIENT_SECRET_BASIC}
082         */
083        public static ClientAuthenticationMethod getDefault() {
084
085                return CLIENT_SECRET_BASIC;
086        }
087
088
089        /**
090         * Creates a new client authentication method with the specified value.
091         *
092         * @param value The authentication method value. Must not be 
093         *              {@code null} or empty string.
094         */
095        public ClientAuthenticationMethod(final String value) {
096
097                super(value);
098        }
099
100
101        @Override
102        public boolean equals(final Object object) {
103        
104                return object != null && 
105                       object instanceof ClientAuthenticationMethod && 
106                       this.toString().equals(object.toString());
107        }
108}