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 * Copyright (c) 2003, 2018, Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation. Oracle designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Oracle in the LICENSE file that accompanied this code.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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 */

package java.net;

import java.security.cert.Certificate;
import javax.net.ssl.SSLSession;
import javax.net.ssl.SSLPeerUnverifiedException;
import java.security.Principal;
import java.util.List;
import java.util.Optional;

/**
 * Represents a cache response originally retrieved through secure
 * means, such as TLS.
 *
 * @since 1.5
 */
public abstract class SecureCacheResponse extends CacheResponse {
 /**
 * Returns the cipher suite in use on the original connection that
 * retrieved the network resource.
 *
 * @return a string representing the cipher suite
 */
 public abstract String getCipherSuite();

 /**
 * Returns the certificate chain that were sent to the server during
 * handshaking of the original connection that retrieved the
 * network resource. Note: This method is useful only
 * when using certificate-based cipher suites.
 *
 * @return an immutable List of Certificate representing the
 * certificate chain that was sent to the server. If no
 * certificate chain was sent, null will be returned.
 * @see #getLocalPrincipal()
 */
 public abstract List<Certificate> getLocalCertificateChain();

 /**
 * Returns the server's certificate chain, which was established as
 * part of defining the session in the original connection that
 * retrieved the network resource, from cache. Note: This method
 * can be used only when using certificate-based cipher suites;
 * using it with non-certificate-based cipher suites, such as
 * Kerberos, will throw an SSLPeerUnverifiedException.
 *
 * @return an immutable List of Certificate representing the server's
 * certificate chain.
 * @throws SSLPeerUnverifiedException if the peer is not verified.
 * @see #getPeerPrincipal()
 */
 public abstract List<Certificate> getServerCertificateChain()
 throws SSLPeerUnverifiedException;

 /**
 * Returns the server's principal which was established as part of
 * defining the session during the original connection that
 * retrieved the network resource.
 *
 * @return the server's principal. Returns an X500Principal of the
 * end-entity certificate for X509-based cipher suites, and
 * KerberosPrincipal for Kerberos cipher suites.
 *
 * @throws SSLPeerUnverifiedException if the peer was not verified.
 *
 * @see #getServerCertificateChain()
 * @see #getLocalPrincipal()
 */
 public abstract Principal getPeerPrincipal()
 throws SSLPeerUnverifiedException;

 /**
 * Returns the principal that was sent to the server during
 * handshaking in the original connection that retrieved the
 * network resource.
 *
 * @return the principal sent to the server. Returns an X500Principal
 * of the end-entity certificate for X509-based cipher suites, and
 * KerberosPrincipal for Kerberos cipher suites. If no principal was
 * sent, then null is returned.
 *
 * @see #getLocalCertificateChain()
 * @see #getPeerPrincipal()
 */
 public abstract Principal getLocalPrincipal();

 /**
 * Returns an {@link Optional} containing the {@code SSLSession} in
 * use on the original connection that retrieved the network resource.
 * Returns an empty {@code Optional} if the underlying implementation
 * does not support this method.
 *
 * @implSpec For compatibility, the default implementation of this
 * method returns an empty {@code Optional}. Subclasses
 * should override this method with an appropriate
 * implementation since an application may need to access
 * additional parameters associated with the SSL session.
 *
 * @return an {@link Optional} containing the {@code SSLSession} in
 * use on the original connection
 *
 * @see SSLSession
 *
 * @since 12
 */
 public Optional<SSLSession> getSSLSession() {
 return Optional.empty();
 }
}