https://tomcat.apache.org/: Tomcat Connectors and HTTP parser 
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 *  Licensed to the Apache Software Foundation (ASF) under one or more
 *  contributor license agreements.  See the NOTICE file distributed with
 *  this work for additional information regarding copyright ownership.
 *  The ASF licenses this file to You under the Apache License, Version 2.0
 *  (the "License"); you may not use this file except in compliance with
 *  the License.  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 *  Unless required by applicable law or agreed to in writing, software
 *  distributed under the License is distributed on an "AS IS" BASIS,
 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *  See the License for the specific language governing permissions and
 *  limitations under the License.
 */
package org.apache.tomcat.util.net;

import java.util.List;

import javax.net.ssl.KeyManager;
import javax.net.ssl.SSLSessionContext;
import javax.net.ssl.TrustManager;


Provides a common interface for SSLImplementations to create the necessary JSSE implementation objects for TLS connections created via the JSSE API. 
/**
 * Provides a common interface for {@link SSLImplementation}s to create the
 * necessary JSSE implementation objects for TLS connections created via the
 * JSSE API.
 */
public interface SSLUtil {

    public SSLContext createSSLContext(List<String> negotiableProtocols) throws Exception;

    public KeyManager[] getKeyManagers() throws Exception;

    public TrustManager[] getTrustManagers() throws Exception;

    public void configureSessionContext(SSLSessionContext sslSessionContext);

    
The set of enabled protocols is the intersection of the implemented
protocols and the configured protocols. If no protocols are explicitly
configured, then all of the implemented protocols will be included in the
returned array.

Throws:
Returns:The protocols currently enabled and available for clients to
        select from for the associated connection
/**
     * The set of enabled protocols is the intersection of the implemented
     * protocols and the configured protocols. If no protocols are explicitly
     * configured, then all of the implemented protocols will be included in the
     * returned array.
     *
     * @return The protocols currently enabled and available for clients to
     *         select from for the associated connection
     *
     * @throws IllegalArgumentException  If there is no intersection between the
     *         implemented and configured protocols
     */
    public String[] getEnabledProtocols() throws IllegalArgumentException;

    
The set of enabled ciphers is the intersection of the implemented ciphers
and the configured ciphers. If no ciphers are explicitly configured, then
the default ciphers will be included in the returned array.

 The ciphers used during the TLS handshake may be further restricted by the getEnabledProtocols() and the certificates. 
Throws:
Returns:The ciphers currently enabled and available for clients to select
        from for the associated connection
/**
     * The set of enabled ciphers is the intersection of the implemented ciphers
     * and the configured ciphers. If no ciphers are explicitly configured, then
     * the default ciphers will be included in the returned array.
     * <p>
     * The ciphers used during the TLS handshake may be further restricted by
     * the {@link #getEnabledProtocols()} and the certificates.
     *
     * @return The ciphers currently enabled and available for clients to select
     *         from for the associated connection
     *
     * @throws IllegalArgumentException  If there is no intersection between the
     *         implemented and configured ciphers
     */
    public String[] getEnabledCiphers() throws IllegalArgumentException;

    
Optional interface that can be implemented by SSLEngines to indicate that they support ALPN and can provided the protocol agreed with the client. 
/**
     * Optional interface that can be implemented by
     * {@link javax.net.ssl.SSLEngine}s to indicate that they support ALPN and
     * can provided the protocol agreed with the client.
     */
    public interface ProtocolInfo {
        
ALPN information.

Returns:the protocol selected using ALPN
/**
         * ALPN information.
         * @return the protocol selected using ALPN
         */
        public String getNegotiatedProtocol();
    }
}