org.apache.hadoop.crypto.key.KeyProviderDelegationTokenExtension Maven / Gradle / Ivy
/**
* 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.hadoop.crypto.key;
import org.apache.hadoop.security.Credentials;
import org.apache.hadoop.security.token.Token;
import java.io.IOException;
/**
* A KeyProvider extension with the ability to add a renewer's Delegation
* Tokens to the provided Credentials.
*/
public class KeyProviderDelegationTokenExtension extends
KeyProviderExtension
{
private static DelegationTokenExtension DEFAULT_EXTENSION =
new DefaultDelegationTokenExtension();
/**
* DelegationTokenExtension is a type of Extension that exposes methods to
* needed to work with Delegation Tokens.
*/
public interface DelegationTokenExtension extends
KeyProviderExtension.Extension {
/**
* The implementer of this class will take a renewer and add all
* delegation tokens associated with the renewer to the
* Credentials object if it is not already present,
* @param renewer the user allowed to renew the delegation tokens
* @param credentials cache in which to add new delegation tokens
* @return list of new delegation tokens
* @throws IOException thrown if IOException if an IO error occurs.
*/
public Token[] addDelegationTokens(final String renewer,
Credentials credentials) throws IOException;
}
/**
* Default implementation of {@link DelegationTokenExtension} that
* implements the method as a no-op.
*/
private static class DefaultDelegationTokenExtension implements
DelegationTokenExtension {
@Override
public Token[] addDelegationTokens(String renewer,
Credentials credentials) {
return null;
}
}
private KeyProviderDelegationTokenExtension(KeyProvider keyProvider,
DelegationTokenExtension extensions) {
super(keyProvider, extensions);
}
/**
* Passes the renewer and Credentials object to the underlying
* {@link DelegationTokenExtension}
* @param renewer the user allowed to renew the delegation tokens
* @param credentials cache in which to add new delegation tokens
* @return list of new delegation tokens
* @throws IOException thrown if IOException if an IO error occurs.
*/
public Token[] addDelegationTokens(final String renewer,
Credentials credentials) throws IOException {
return getExtension().addDelegationTokens(renewer, credentials);
}
/**
* Creates a KeyProviderDelegationTokenExtension using a given
* {@link KeyProvider}.
*
* If the given KeyProvider implements the
* {@link DelegationTokenExtension} interface the KeyProvider
* itself will provide the extension functionality, otherwise a default
* extension implementation will be used.
*
* @param keyProvider KeyProvider to use to create the
* KeyProviderDelegationTokenExtension extension.
* @return a KeyProviderDelegationTokenExtension instance
* using the given KeyProvider.
*/
public static KeyProviderDelegationTokenExtension
createKeyProviderDelegationTokenExtension(KeyProvider keyProvider) {
DelegationTokenExtension delTokExtension =
(keyProvider instanceof DelegationTokenExtension) ?
(DelegationTokenExtension) keyProvider :
DEFAULT_EXTENSION;
return new KeyProviderDelegationTokenExtension(
keyProvider, delTokExtension);
}
}