io.netty.handler.ssl.ApplicationProtocolConfig Maven / Gradle / Ivy
/*
* Copyright 2014 The Netty Project
*
* The Netty Project 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:
*
* https://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 io.netty.handler.ssl;
import java.util.Collections;
import java.util.List;
import javax.net.ssl.SSLEngine;
import static io.netty.handler.ssl.ApplicationProtocolUtil.toList;
import static io.netty.util.internal.ObjectUtil.checkNotNull;
import static io.netty.util.internal.ObjectUtil.checkNonEmpty;
/**
* Provides an {@link SSLEngine} agnostic way to configure a {@link ApplicationProtocolNegotiator}.
*/
public final class ApplicationProtocolConfig {
/**
* The configuration that disables application protocol negotiation.
*/
public static final ApplicationProtocolConfig DISABLED = new ApplicationProtocolConfig();
private final List supportedProtocols;
private final Protocol protocol;
private final SelectorFailureBehavior selectorBehavior;
private final SelectedListenerFailureBehavior selectedBehavior;
/**
* Create a new instance.
* @param protocol The application protocol functionality to use.
* @param selectorBehavior How the peer selecting the protocol should behave.
* @param selectedBehavior How the peer being notified of the selected protocol should behave.
* @param supportedProtocols The order of iteration determines the preference of support for protocols.
*/
public ApplicationProtocolConfig(Protocol protocol, SelectorFailureBehavior selectorBehavior,
SelectedListenerFailureBehavior selectedBehavior, Iterable supportedProtocols) {
this(protocol, selectorBehavior, selectedBehavior, toList(supportedProtocols));
}
/**
* Create a new instance.
* @param protocol The application protocol functionality to use.
* @param selectorBehavior How the peer selecting the protocol should behave.
* @param selectedBehavior How the peer being notified of the selected protocol should behave.
* @param supportedProtocols The order of iteration determines the preference of support for protocols.
*/
public ApplicationProtocolConfig(Protocol protocol, SelectorFailureBehavior selectorBehavior,
SelectedListenerFailureBehavior selectedBehavior, String... supportedProtocols) {
this(protocol, selectorBehavior, selectedBehavior, toList(supportedProtocols));
}
/**
* Create a new instance.
* @param protocol The application protocol functionality to use.
* @param selectorBehavior How the peer selecting the protocol should behave.
* @param selectedBehavior How the peer being notified of the selected protocol should behave.
* @param supportedProtocols The order of iteration determines the preference of support for protocols.
*/
private ApplicationProtocolConfig(
Protocol protocol, SelectorFailureBehavior selectorBehavior,
SelectedListenerFailureBehavior selectedBehavior, List supportedProtocols) {
this.supportedProtocols = Collections.unmodifiableList(checkNotNull(supportedProtocols, "supportedProtocols"));
this.protocol = checkNotNull(protocol, "protocol");
this.selectorBehavior = checkNotNull(selectorBehavior, "selectorBehavior");
this.selectedBehavior = checkNotNull(selectedBehavior, "selectedBehavior");
if (protocol == Protocol.NONE) {
throw new IllegalArgumentException("protocol (" + Protocol.NONE + ") must not be " + Protocol.NONE + '.');
}
checkNonEmpty(supportedProtocols, "supportedProtocols");
}
/**
* A special constructor that is used to instantiate {@link #DISABLED}.
*/
private ApplicationProtocolConfig() {
supportedProtocols = Collections.emptyList();
protocol = Protocol.NONE;
selectorBehavior = SelectorFailureBehavior.CHOOSE_MY_LAST_PROTOCOL;
selectedBehavior = SelectedListenerFailureBehavior.ACCEPT;
}
/**
* Defines which application level protocol negotiation to use.
*/
public enum Protocol {
NONE, NPN, ALPN, NPN_AND_ALPN
}
/**
* Defines the most common behaviors for the peer that selects the application protocol.
*/
public enum SelectorFailureBehavior {
/**
* If the peer who selects the application protocol doesn't find a match this will result in the failing the
* handshake with a fatal alert.
*
* For example in the case of ALPN this will result in a
* no_application_protocol(120) alert.
*/
FATAL_ALERT,
/**
* If the peer who selects the application protocol doesn't find a match it will pretend no to support
* the TLS extension by not advertising support for the TLS extension in the handshake. This is used in cases
* where a "best effort" is desired to talk even if there is no matching protocol.
*/
NO_ADVERTISE,
/**
* If the peer who selects the application protocol doesn't find a match it will just select the last protocol
* it advertised support for. This is used in cases where a "best effort" is desired to talk even if there
* is no matching protocol, and the assumption is the "most general" fallback protocol is typically listed last.
*
* This may be illegal for some RFCs but was
* observed behavior by some SSL implementations, and is supported for flexibility/compatibility.
*/
CHOOSE_MY_LAST_PROTOCOL
}
/**
* Defines the most common behaviors for the peer which is notified of the selected protocol.
*/
public enum SelectedListenerFailureBehavior {
/**
* If the peer who is notified what protocol was selected determines the selection was not matched, or the peer
* didn't advertise support for the TLS extension then the handshake will continue and the application protocol
* is assumed to be accepted.
*/
ACCEPT,
/**
* If the peer who is notified what protocol was selected determines the selection was not matched, or the peer
* didn't advertise support for the TLS extension then the handshake will be failed with a fatal alert.
*/
FATAL_ALERT,
/**
* If the peer who is notified what protocol was selected determines the selection was not matched, or the peer
* didn't advertise support for the TLS extension then the handshake will continue assuming the last protocol
* supported by this peer is used. This is used in cases where a "best effort" is desired to talk even if there
* is no matching protocol, and the assumption is the "most general" fallback protocol is typically listed last.
*/
CHOOSE_MY_LAST_PROTOCOL
}
/**
* The application level protocols supported.
*/
public List supportedProtocols() {
return supportedProtocols;
}
/**
* Get which application level protocol negotiation to use.
*/
public Protocol protocol() {
return protocol;
}
/**
* Get the desired behavior for the peer who selects the application protocol.
*/
public SelectorFailureBehavior selectorFailureBehavior() {
return selectorBehavior;
}
/**
* Get the desired behavior for the peer who is notified of the selected protocol.
*/
public SelectedListenerFailureBehavior selectedListenerFailureBehavior() {
return selectedBehavior;
}
}