org.apache.kafka.common.network.SslChannelBuilder Maven / Gradle / Ivy
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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,
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* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.kafka.common.network;
import org.apache.kafka.common.KafkaException;
import org.apache.kafka.common.config.SslConfigs;
import org.apache.kafka.common.config.internals.BrokerSecurityConfigs;
import org.apache.kafka.common.memory.MemoryPool;
import org.apache.kafka.common.security.auth.KafkaPrincipal;
import org.apache.kafka.common.security.auth.KafkaPrincipalBuilder;
import org.apache.kafka.common.security.auth.SslAuthenticationContext;
import org.apache.kafka.common.security.ssl.SslFactory;
import org.apache.kafka.common.security.ssl.SslPrincipalMapper;
import org.apache.kafka.common.utils.LogContext;
import org.apache.kafka.common.utils.Utils;
import org.slf4j.Logger;
import java.io.Closeable;
import java.io.IOException;
import java.net.InetAddress;
import java.net.InetSocketAddress;
import java.nio.channels.SelectionKey;
import java.nio.channels.SocketChannel;
import java.util.Map;
import java.util.Set;
import java.util.function.Supplier;
public class SslChannelBuilder implements ChannelBuilder, ListenerReconfigurable {
private final ListenerName listenerName;
private final boolean isInterBrokerListener;
private SslFactory sslFactory;
private Mode mode;
private Map configs;
private SslPrincipalMapper sslPrincipalMapper;
private final Logger log;
/**
* Constructs an SSL channel builder. ListenerName is provided only
* for server channel builder and will be null for client channel builder.
*/
public SslChannelBuilder(Mode mode,
ListenerName listenerName,
boolean isInterBrokerListener,
LogContext logContext) {
this.mode = mode;
this.listenerName = listenerName;
this.isInterBrokerListener = isInterBrokerListener;
this.log = logContext.logger(getClass());
}
public void configure(Map configs) throws KafkaException {
try {
this.configs = configs;
String sslPrincipalMappingRules = (String) configs.get(BrokerSecurityConfigs.SSL_PRINCIPAL_MAPPING_RULES_CONFIG);
if (sslPrincipalMappingRules != null)
sslPrincipalMapper = SslPrincipalMapper.fromRules(sslPrincipalMappingRules);
this.sslFactory = new SslFactory(mode, null, isInterBrokerListener);
this.sslFactory.configure(this.configs);
} catch (Exception e) {
throw new KafkaException(e);
}
}
@Override
public Set reconfigurableConfigs() {
return SslConfigs.RECONFIGURABLE_CONFIGS;
}
@Override
public void validateReconfiguration(Map configs) {
sslFactory.validateReconfiguration(configs);
}
@Override
public void reconfigure(Map configs) {
sslFactory.reconfigure(configs);
}
@Override
public ListenerName listenerName() {
return listenerName;
}
@Override
public KafkaChannel buildChannel(String id, SelectionKey key, int maxReceiveSize,
MemoryPool memoryPool, ChannelMetadataRegistry metadataRegistry) throws KafkaException {
try {
SslTransportLayer transportLayer = buildTransportLayer(sslFactory, id, key,
peerHost(key), metadataRegistry);
Supplier authenticatorCreator = () ->
new SslAuthenticator(configs, transportLayer, listenerName, sslPrincipalMapper);
return new KafkaChannel(id, transportLayer, authenticatorCreator, maxReceiveSize,
memoryPool != null ? memoryPool : MemoryPool.NONE, metadataRegistry);
} catch (Exception e) {
log.info("Failed to create channel due to ", e);
throw new KafkaException(e);
}
}
@Override
public void close() {
if (sslFactory != null) sslFactory.close();
}
protected SslTransportLayer buildTransportLayer(SslFactory sslFactory, String id, SelectionKey key,
String host, ChannelMetadataRegistry metadataRegistry) throws IOException {
SocketChannel socketChannel = (SocketChannel) key.channel();
return SslTransportLayer.create(id, key, sslFactory.createSslEngine(host, socketChannel.socket().getPort()),
metadataRegistry);
}
/**
* Returns host/IP address of remote host without reverse DNS lookup to be used as the host
* for creating SSL engine. This is used as a hint for session reuse strategy and also for
* hostname verification of server hostnames.
*
* Scenarios:
*
* - Server-side
*
* - Server accepts connection from a client. Server knows only client IP
* address. We want to avoid reverse DNS lookup of the client IP address since the server
* does not verify or use client hostname. The IP address can be used directly.
*
*
* - Client-side
*
* - Client connects to server using hostname. No lookup is necessary
* and the hostname should be used to create the SSL engine. This hostname is validated
* against the hostname in SubjectAltName (dns) or CommonName in the certificate if
* hostname verification is enabled. Authentication fails if hostname does not match.
* - Client connects to server using IP address, but certificate contains only
* SubjectAltName (dns). Use of reverse DNS lookup to determine hostname introduces
* a security vulnerability since authentication would be reliant on a secure DNS.
* Hence hostname verification should fail in this case.
* - Client connects to server using IP address and certificate contains
* SubjectAltName (ipaddress). This could be used when Kafka is on a private network.
* If reverse DNS lookup is used, authentication would succeed using IP address if lookup
* fails and IP address is used, but authentication would fail if lookup succeeds and
* dns name is used. For consistency and to avoid dependency on a potentially insecure
* DNS, reverse DNS lookup should be avoided and the IP address specified by the client for
* connection should be used to create the SSL engine.
*
*
*/
private String peerHost(SelectionKey key) {
SocketChannel socketChannel = (SocketChannel) key.channel();
return new InetSocketAddress(socketChannel.socket().getInetAddress(), 0).getHostString();
}
/**
* Note that client SSL authentication is handled in {@link SslTransportLayer}. This class is only used
* to transform the derived principal using a {@link KafkaPrincipalBuilder} configured by the user.
*/
private static class SslAuthenticator implements Authenticator {
private final SslTransportLayer transportLayer;
private final KafkaPrincipalBuilder principalBuilder;
private final ListenerName listenerName;
private SslAuthenticator(Map configs, SslTransportLayer transportLayer, ListenerName listenerName, SslPrincipalMapper sslPrincipalMapper) {
this.transportLayer = transportLayer;
this.principalBuilder = ChannelBuilders.createPrincipalBuilder(configs, transportLayer, this, null, sslPrincipalMapper);
this.listenerName = listenerName;
}
/**
* No-Op for plaintext authenticator
*/
@Override
public void authenticate() {}
/**
* Constructs Principal using configured principalBuilder.
* @return the built principal
*/
@Override
public KafkaPrincipal principal() {
InetAddress clientAddress = transportLayer.socketChannel().socket().getInetAddress();
// listenerName should only be null in Client mode where principal() should not be called
if (listenerName == null)
throw new IllegalStateException("Unexpected call to principal() when listenerName is null");
SslAuthenticationContext context = new SslAuthenticationContext(
transportLayer.sslSession(),
clientAddress,
listenerName.value());
return principalBuilder.build(context);
}
@Override
public void close() throws IOException {
if (principalBuilder instanceof Closeable)
Utils.closeQuietly((Closeable) principalBuilder, "principal builder");
}
/**
* SslAuthenticator doesn't implement any additional authentication mechanism.
* @return true
*/
@Override
public boolean complete() {
return true;
}
}
}