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Posted to commits@kafka.apache.org by gw...@apache.org on 2016/05/05 20:33:55 UTC
kafka-site git commit: Docs for 0.10.0.0, fourth release candidate
Repository: kafka-site
Updated Branches:
refs/heads/asf-site 35b3bbb22 -> 1ad8525f1
Docs for 0.10.0.0, fourth release candidate
Project: http://git-wip-us.apache.org/repos/asf/kafka-site/repo
Commit: http://git-wip-us.apache.org/repos/asf/kafka-site/commit/1ad8525f
Tree: http://git-wip-us.apache.org/repos/asf/kafka-site/tree/1ad8525f
Diff: http://git-wip-us.apache.org/repos/asf/kafka-site/diff/1ad8525f
Branch: refs/heads/asf-site
Commit: 1ad8525f10fd11ea7f23b35533615df0abdb8b62
Parents: 35b3bbb
Author: Gwen Shapira <cs...@gmail.com>
Authored: Thu May 5 13:33:45 2016 -0700
Committer: Gwen Shapira <cs...@gmail.com>
Committed: Thu May 5 13:33:45 2016 -0700
----------------------------------------------------------------------
0100/protocol.html | 15 ++
0100/security.html | 372 ++++++++++++++++++++++++++++++++++++------------
2 files changed, 293 insertions(+), 94 deletions(-)
----------------------------------------------------------------------
http://git-wip-us.apache.org/repos/asf/kafka-site/blob/1ad8525f/0100/protocol.html
----------------------------------------------------------------------
diff --git a/0100/protocol.html b/0100/protocol.html
index cb359f1..c26f16b 100644
--- a/0100/protocol.html
+++ b/0100/protocol.html
@@ -114,6 +114,21 @@
<p>Currently all versions are baselined at 0, as we evolve these APIs we will indicate the format for each version individually.</p>
+<h5><a id="sasl_handshake" href="#sasl_handshake">SASL Authentication Sequence</a></h5>
+<p>The following sequence is used for SASL authentication:
+<ol>
+ <li>Kafka <code>ApiVersionsRequest</code> may be sent by the client to obtain the version ranges of requests supported by the broker. This is optional.</li>
+ <li>Kafka <code>SaslHandshakeRequest</code> containing the SASL mechanism for authentication is sent by the client. If the requested mechanism is not enabled
+ in the server, the server responds with the list of supported mechanisms and closes the client connection. If the mechanism is enabled
+ in the server, the server sends a successful response and continues with SASL authentication.
+ <li>The actual SASL authentication is now performed. A series of SASL client and server tokens corresponding to the mechanism are sent as opaque
+ packets. These packets contain a 32-bit size followed by the token as defined by the protocol for the SASL mechanism.
+ <li>If authentication succeeds, subsequent packets are handled as Kafka API requests. Otherwise, the client connection is closed.
+</ol>
+<p>For interoperability with 0.9.0.x clients, the first packet received by the server is handled as a SASL/GSSAPI client token if it is not a valid
+Kafka request. SASL/GSSAPI authentication is performed starting with this packet, skipping the first two steps above.</p>
+
+
<h4><a id="protocol_details" href="#protocol_details">The Protocol</a></h4>
<h5><a id="protocol_types" href="#protocol_types">Protocol Primitive Types</a></h5>
http://git-wip-us.apache.org/repos/asf/kafka-site/blob/1ad8525f/0100/security.html
----------------------------------------------------------------------
diff --git a/0100/security.html b/0100/security.html
index a2e7816..3e5085b 100644
--- a/0100/security.html
+++ b/0100/security.html
@@ -18,7 +18,8 @@
<h3><a id="security_overview" href="#security_overview">7.1 Security Overview</a></h3>
In release 0.9.0.0, the Kafka community added a number of features that, used either separately or together, increases security in a Kafka cluster. These features are considered to be of beta quality. The following security measures are currently supported:
<ol>
- <li>Authentication of connections to brokers from clients (producers and consumers), other brokers and tools, using either SSL or SASL (Kerberos)</li>
+ <li>Authentication of connections to brokers from clients (producers and consumers), other brokers and tools, using either SSL or SASL (Kerberos).
+ SASL/PLAIN can also be used from release 0.10.0.0 onwards.</li>
<li>Authentication of connections from brokers to ZooKeeper</li>
<li>Encryption of data transferred between brokers and clients, between brokers, or between brokers and tools using SSL (Note that there is a performance degradation when SSL is enabled, the magnitude of which depends on the CPU type and the JVM implementation.)</li>
<li>Authorization of read / write operations by clients</li>
@@ -182,22 +183,95 @@ Apache Kafka allows clients to connect over SSL. By default SSL is disabled but
<h3><a id="security_sasl" href="#security_sasl">7.3 Authentication using SASL</a></h3>
<ol>
- <li><h4><a id="security_sasl_prereq" href="#security_sasl_prereq">Prerequisites</a></h4>
+ <li><h4><a id="security_sasl_brokerconfig"
+ href="#security_sasl_brokerconfig">SASL configuration for Kafka brokers</a></h4>
<ol>
- <li><b>Kerberos</b><br>
- If your organization is already using a Kerberos server (for example, by using Active Directory), there is no need to install a new server just for Kafka. Otherwise you will need to install one, your Linux vendor likely has packages for Kerberos and a short guide on how to install and configure it (<a href="https://help.ubuntu.com/community/Kerberos">Ubuntu</a>, <a href="https://access.redhat.com/documentation/en-US/Red_Hat_Enterprise_Linux/6/html/Managing_Smart_Cards/installing-kerberos.html">Redhat</a>). Note that if you are using Oracle Java, you will need to download JCE policy files for your Java version and copy them to $JAVA_HOME/jre/lib/security.</li>
- <li><b>Create Kerberos Principals</b><br>
- If you are using the organization's Kerberos or Active Directory server, ask your Kerberos administrator for a principal for each Kafka broker in your cluster and for every operating system user that will access Kafka with Kerberos authentication (via clients and tools).</br>
- If you have installed your own Kerberos, you will need to create these principals yourself using the following commands:
+ <li>Select one or more supported mechanisms to enable in the broker. <tt>GSSAPI</tt>
+ and <tt>PLAIN</tt> are the mechanisms currently supported in Kafka.</li>
+ <li>Add a JAAS config file for the selected mechanisms as described in the examples
+ for setting up <a href="#security_sasl_kerberos_brokerconfig">GSSAPI (Kerberos)</a>
+ or <a href="#security_sasl_plain_brokerconfig">PLAIN</a>.</li>
+ <li>Pass the JAAS config file location as JVM parameter to each Kafka broker.
+ For example:
+ <pre> -Djava.security.auth.login.config=/etc/kafka/kafka_server_jaas.conf</pre></li>
+ <li>Configure a SASL port in server.properties, by adding at least one of
+ SASL_PLAINTEXT or SASL_SSL to the <i>listeners</i> parameter, which
+ contains one or more comma-separated values:
+ <pre> listeners=SASL_PLAINTEXT://host.name:port</pre>
+ If SASL_SSL is used, then <a href="#security_ssl">SSL must also be
+ configured</a>. If you are only configuring a SASL port (or if you want
+ the Kafka brokers to authenticate each other using SASL) then make sure
+ you set the same SASL protocol for inter-broker communication:
+ <pre> security.inter.broker.protocol=SASL_PLAINTEXT (or SASL_SSL)</pre></li>
+ <li>Enable one or more SASL mechanisms in server.properties:
+ <pre> sasl.enabled.mechanisms=GSSAPI (,PLAIN)</pre></li>
+ <li>Configure the SASL mechanism for inter-broker communication in server.properties
+ if using SASL for inter-broker communication:
+ <pre> sasl.mechanism.inter.broker.protocol=GSSAPI (or PLAIN)</pre></li>
+ <li>Follow the steps in <a href="#security_sasl_kerberos_brokerconfig">GSSAPI (Kerberos)</a>
+ or <a href="#security_sasl_plain_brokerconfig">PLAIN</a> to configure SASL
+ for the enabled mechanisms. To enable multiple mechanisms in the broker, follow
+ the steps <a href="#security_sasl_multimechanism">here</a>.</li>
+ <u><a id="security_sasl_brokernotes" href="#security_sasl_brokernotes">Important notes:</a></u>
+ <ol>
+ <li><tt>KafkaServer</tt> is the section name in the JAAS file used by each
+ KafkaServer/Broker. This section provides SASL configuration options
+ for the broker including any SASL client connections made by the broker
+ for inter-broker communication.</li>
+ <li><tt>Client</tt> section is used to authenticate a SASL connection with
+ zookeeper. It also allows the brokers to set SASL ACL on zookeeper
+ nodes which locks these nodes down so that only the brokers can
+ modify it. It is necessary to have the same principal name across all
+ brokers. If you want to use a section name other than Client, set the
+ system property <tt>zookeeper.sasl.client</tt> to the appropriate
+ name (<i>e.g.</i>, <tt>-Dzookeeper.sasl.client=ZkClient</tt>).</li>
+ <li>ZooKeeper uses "zookeeper" as the service name by default. If you
+ want to change this, set the system property
+ <tt>zookeeper.sasl.client.username</tt> to the appropriate name
+ (<i>e.g.</i>, <tt>-Dzookeeper.sasl.client.username=zk</tt>).</li>
+ </ol>
+ </ol>
+ </li>
+ <li><h4><a id="security_sasl_clientconfig"
+ href="#security_sasl_clientconfig">SASL configuration for Kafka clients</a></h4>
+ SASL authentication is only supported for the new Java Kafka producer and
+ consumer, the older API is not supported. To configure SASL authentication
+ on the clients:
+ <ol>
+ <li>Select a SASL mechanism for authentication.</li>
+ <li>Add a JAAS config file for the selected mechanism as described in the examples
+ for setting up <a href="#security_sasl_kerberos_clientconfig">GSSAPI (Kerberos)</a>
+ or <a href="#security_sasl_plain_clientconfig">PLAIN</a>. <tt>KafkaClient</tt> is the
+ section name in the JAAS file used by Kafka clients.</li>
+ <li>Pass the JAAS config file location as JVM parameter to each client JVM. For example:
+ <pre> -Djava.security.auth.login.config=/etc/kafka/kafka_client_jaas.conf</pre></li>
+ <li>Configure the following properties in producer.properties or
+ consumer.properties:
+ <pre> security.protocol=SASL_PLAINTEXT (or SASL_SSL)
+ sasl.mechanism=GSSAPI (or PLAIN)</pre></li>
+ <li>Follow the steps in <a href="#security_sasl_kerberos_clientconfig">GSSAPI (Kerberos)</a>
+ or <a href="#security_sasl_plain_clientconfig">PLAIN</a> to configure SASL
+ for the selected mechanism.</li>
+ </ol>
+ </li>
+ <li><h4><a id="security_sasl_kerberos" href="#security_sasl_kerberos">Authentication using SASL/Kerberos</a></h4>
+ <ol>
+ <li><h5><a id="security_sasl_kerberos_prereq" href="#security_sasl_kerberos_prereq">Prerequisites</a></h5>
+ <ol>
+ <li><b>Kerberos</b><br>
+ If your organization is already using a Kerberos server (for example, by using Active Directory), there is no need to install a new server just for Kafka. Otherwise you will need to install one, your Linux vendor likely has packages for Kerberos and a short guide on how to install and configure it (<a href="https://help.ubuntu.com/community/Kerberos">Ubuntu</a>, <a href="https://access.redhat.com/documentation/en-US/Red_Hat_Enterprise_Linux/6/html/Managing_Smart_Cards/installing-kerberos.html">Redhat</a>). Note that if you are using Oracle Java, you will need to download JCE policy files for your Java version and copy them to $JAVA_HOME/jre/lib/security.</li>
+ <li><b>Create Kerberos Principals</b><br>
+ If you are using the organization's Kerberos or Active Directory server, ask your Kerberos administrator for a principal for each Kafka broker in your cluster and for every operating system user that will access Kafka with Kerberos authentication (via clients and tools).</br>
+ If you have installed your own Kerberos, you will need to create these principals yourself using the following commands:
<pre>
sudo /usr/sbin/kadmin.local -q 'addprinc -randkey kafka/{hostname}@{REALM}'
sudo /usr/sbin/kadmin.local -q "ktadd -k /etc/security/keytabs/{keytabname}.keytab kafka/{hostname}@{REALM}"</pre></li>
- <li><b>Make sure all hosts can be reachable using hostnames</b> - it is a Kerberos requirement that all your hosts can be resolved with their FQDNs.</li>
- </ol>
- <li><h4><a id="security_sasl_brokerconfig" href="#security_sasl_brokerconfig">Configuring Kafka Brokers</a></h4>
- <ol>
- <li>Add a suitably modified JAAS file similar to the one below to each Kafka broker's config directory, let's call it kafka_server_jaas.conf for this example (note that each broker should have its own keytab):
- <pre>
+ <li><b>Make sure all hosts can be reachable using hostnames</b> - it is a Kerberos requirement that all your hosts can be resolved with their FQDNs.</li>
+ </ol>
+ <li><h5><a id="security_sasl_kerberos_brokerconfig" href="#security_sasl_kerberos_brokerconfig">Configuring Kafka Brokers</a></h5>
+ <ol>
+ <li>Add a suitably modified JAAS file similar to the one below to each Kafka broker's config directory, let's call it kafka_server_jaas.conf for this example (note that each broker should have its own keytab):
+ <pre>
KafkaServer {
com.sun.security.auth.module.Krb5LoginModule required
useKeyTab=true
@@ -215,40 +289,31 @@ Apache Kafka allows clients to connect over SSL. By default SSL is disabled but
principal="kafka/kafka1.hostname.com@EXAMPLE.COM";
};</pre>
- </li>
- <li>Pass the JAAS and optionally the krb5 file locations as JVM parameters to each Kafka broker (see <a href="https://docs.oracle.com/javase/8/docs/technotes/guides/security/jgss/tutorials/KerberosReq.html">here</a> for more details):
- <pre>
- -Djava.security.krb5.conf=/etc/kafka/krb5.conf
+ </li>
+ <tt>KafkaServer</tt> section in the JAAS file tells the broker which principal to use and the location of the keytab where this principal is stored. It
+ allows the broker to login using the keytab specified in this section. See <a href="#security_sasl_brokernotes">notes</a> for more details on Zookeeper SASL configuration.
+ <li>Pass the JAAS and optionally the krb5 file locations as JVM parameters to each Kafka broker (see <a href="https://docs.oracle.com/javase/8/docs/technotes/guides/security/jgss/tutorials/KerberosReq.html">here</a> for more details):
+ <pre> -Djava.security.krb5.conf=/etc/kafka/krb5.conf
-Djava.security.auth.login.config=/etc/kafka/kafka_server_jaas.conf</pre>
- </li>
- <li>Make sure the keytabs configured in the JAAS file are readable by the operating system user who is starting kafka broker.</li>
- <li>Configure a SASL port in server.properties, by adding at least one of SASL_PLAINTEXT or SASL_SSL to the <i>listeners</i> parameter, which contains one or more comma-separated values:
- <pre>
- listeners=SASL_PLAINTEXT://host.name:port</pre>
- If SASL_SSL is used, then <a href="#security_ssl">SSL must also be configured</a>.
- If you are only configuring a SASL port (or if you want the Kafka brokers to authenticate each other using SASL) then make sure you set the same SASL protocol for inter-broker communication:
- <pre>
- security.inter.broker.protocol=SASL_PLAINTEXT (or SASL_SSL)</pre></li>
-
- We must also configure the service name in server.properties, which should match the principal name of the kafka brokers. In the above example, principal is "kafka/kafka1.hostname.com@EXAMPLE.com", so:
- <pre>
- sasl.kerberos.service.name=kafka</pre>
-
- <u>Important notes:</u>
- <ol>
- <li>KafkaServer is a section name in JAAS file used by each KafkaServer/Broker. This section tells the broker which principal to use and the location of the keytab where this principal is stored. It allows the broker to login using the keytab specified in this section.</li>
- <li>Client section is used to authenticate a SASL connection with zookeeper. It also allows the brokers to set SASL ACL on zookeeper nodes which locks these nodes down so that only the brokers can modify it. It is necessary to have the same principal name across all brokers. If you want to use a section name other than Client, set the system property <tt>zookeeper.sasl.client</tt> to the appropriate name (<i>e.g.</i>, <tt>-Dzookeeper.sasl.client=ZkClient</tt>).</li>
- <li>ZooKeeper uses "zookeeper" as the service name by default. If you want to change this, set the system property <tt>zookeeper.sasl.client.username</tt> to the appropriate name (<i>e.g.</i>, <tt>-Dzookeeper.sasl.client.username=zk</tt>).</li>
- </ol>
-
- </ol>
- <li><h4><a id="security_sasl_clientconfig" href="#security_sasl_clientconfig">Configuring Kafka Clients</a></h4>
- SASL authentication is only supported for the new kafka producer and consumer, the older API is not supported. To configure SASL authentication on the clients:
- <ol>
- <li>
- Clients (producers, consumers, connect workers, etc) will authenticate to the cluster with their own principal (usually with the same name as the user running the client), so obtain or create these principals as needed. Then create a JAAS file for each principal.
- The KafkaClient section describes how the clients like producer and consumer can connect to the Kafka Broker. The following is an example configuration for a client using a keytab (recommended for long-running processes):
- <pre>
+ </li>
+ <li>Make sure the keytabs configured in the JAAS file are readable by the operating system user who is starting kafka broker.</li>
+ <li>Configure SASL port and SASL mechanisms in server.properties as described <a href="#security_sasl_brokerconfig">here</a>.</pre> For example:
+ <pre> listeners=SASL_PLAINTEXT://host.name:port
+ security.inter.broker.protocol=SASL_PLAINTEXT
+ sasl.mechanism.inter.broker.protocol=GSSAPI
+ sasl.enabled.mechanisms=GSSAPI
+ </pre>
+ </li>We must also configure the service name in server.properties, which should match the principal name of the kafka brokers. In the above example, principal is "kafka/kafka1.hostname.com@EXAMPLE.com", so:
+ <pre> sasl.kerberos.service.name=kafka</pre>
+
+ </ol></li>
+ <li><h5><a id="security_sasl_kerberos_clientconfig" href="#security_kerberos_sasl_clientconfig">Configuring Kafka Clients</a></h5>
+ To configure SASL authentication on the clients:
+ <ol>
+ <li>
+ Clients (producers, consumers, connect workers, etc) will authenticate to the cluster with their own principal (usually with the same name as the user running the client), so obtain or create these principals as needed. Then create a JAAS file for each principal.
+ The KafkaClient section describes how the clients like producer and consumer can connect to the Kafka Broker. The following is an example configuration for a client using a keytab (recommended for long-running processes):
+ <pre>
KafkaClient {
com.sun.security.auth.module.Krb5LoginModule required
useKeyTab=true
@@ -257,93 +322,212 @@ Apache Kafka allows clients to connect over SSL. By default SSL is disabled but
principal="kafka-client-1@EXAMPLE.COM";
};</pre>
- For command-line utilities like kafka-console-consumer or kafka-console-producer, kinit can be used along with "useTicketCache=true" as in:
- <pre>
+ For command-line utilities like kafka-console-consumer or kafka-console-producer, kinit can be used along with "useTicketCache=true" as in:
+ <pre>
KafkaClient {
com.sun.security.auth.module.Krb5LoginModule required
useTicketCache=true;
};</pre>
- </li>
- <li>Pass the JAAS and optionally krb5 file locations as JVM parameters to each client JVM (see <a href="https://docs.oracle.com/javase/8/docs/technotes/guides/security/jgss/tutorials/KerberosReq.html">here</a> for more details):
- <pre>
- -Djava.security.krb5.conf=/etc/kafka/krb5.conf
+ </li>
+ <li>Pass the JAAS and optionally krb5 file locations as JVM parameters to each client JVM (see <a href="https://docs.oracle.com/javase/8/docs/technotes/guides/security/jgss/tutorials/KerberosReq.html">here</a> for more details):
+ <pre> -Djava.security.krb5.conf=/etc/kafka/krb5.conf
-Djava.security.auth.login.config=/etc/kafka/kafka_client_jaas.conf</pre></li>
- <li>Make sure the keytabs configured in the kafka_client_jaas.conf are readable by the operating system user who is starting kafka client.</li>
- <li>Configure the following properties in producer.properties or consumer.properties:
- <pre>
- security.protocol=SASL_PLAINTEXT (or SASL_SSL)
- sasl.kerberos.service.name=kafka</pre>
- </li>
- </ol></li>
-
- <li><h4><a id="security_rolling_upgrade" href="#security_rolling_upgrade">Incorporating Security Features in a Running Cluster</a></h4>
- You can secure a running cluster via one or more of the supported protocols discussed previously. This is done in phases:
- <p></p>
+ <li>Make sure the keytabs configured in the kafka_client_jaas.conf are readable by the operating system user who is starting kafka client.</li>
+ <li>Configure the following properties in producer.properties or consumer.properties:
+ <pre> security.protocol=SASL_PLAINTEXT (or SASL_SSL)
+ sasl.mechanism=GSSAPI
+ sasl.kerberos.service.name=kafka</pre></li>
+ </ol>
+ </li>
+ </ol>
+ </li>
+
+ <li><h4><a id="security_sasl_plain" href="#security_sasl_plain">Authentication using SASL/PLAIN</a></h4>
+ <p>SASL/PLAIN is a simple username/password authentication mechanism that is typically used with TLS for encryption to implement secure authentication.
+ Kafka supports a default implementation for SASL/PLAIN which can be extended for production use as described <a href="#security_sasl_plain_production">here</a>.</p>
+ The username is used as the authenticated <code>Principal</code> for configuration of ACLs etc.
+ <ol>
+ <li><h5><a id="security_sasl_plain_brokerconfig" href="#security_sasl_plain_brokerconfig">Configuring Kafka Brokers</a></h5>
+ <ol>
+ <li>Add a suitably modified JAAS file similar to the one below to each Kafka broker's config directory, let's call it kafka_server_jaas.conf for this example:
+ <pre>
+ KafkaServer {
+ org.apache.kafka.common.security.plain.PlainLoginModule required
+ username="admin"
+ password="admin-secret"
+ user_admin="admin-secret"
+ user_alice="alice-secret";
+ };</pre>
+ This configuration defines two users (<i>admin</i> and <i>alice</i>). The properties <tt>username</tt> and <tt>password</tt>
+ in the <tt>KafkaServer</tt> section are used by the broker to initiate connections to other brokers. In this example,
+ <i>admin</i> is the user for inter-broker communication. The set of properties <tt>user_<i>userName</i></tt> defines
+ the passwords for all users that connect to the broker and the broker validates all client connections including
+ those from other brokers using these properties.</li>
+ <li>Pass the JAAS config file location as JVM parameter to each Kafka broker:
+ <pre> -Djava.security.auth.login.config=/etc/kafka/kafka_server_jaas.conf</pre></li>
+ <li>Configure SASL port and SASL mechanisms in server.properties as described <a href="#security_sasl_brokerconfig">here</a>.</pre> For example:
+ <pre> listeners=SASL_SSL://host.name:port
+ security.inter.broker.protocol=SASL_SSL
+ sasl.mechanism.inter.broker.protocol=PLAIN
+ sasl.enabled.mechanisms=PLAIN</pre></li>
+ </ol>
+ </li>
+
+ <li><h5><a id="security_sasl_plain_clientconfig" href="#security_sasl_plain_clientconfig">Configuring Kafka Clients</a></h5>
+ To configure SASL authentication on the clients:
+ <ol>
+ <li>The <tt>KafkaClient</tt> section describes how the clients like producer and consumer can connect to the Kafka Broker.
+ The following is an example configuration for a client for the PLAIN mechanism:
+ <pre>
+ KafkaClient {
+ org.apache.kafka.common.security.plain.PlainLoginModule required
+ username="alice"
+ password="alice-secret";
+ };</pre>
+ The properties <tt>username</tt> and <tt>password</tt> in the <tt>KafkaClient</tt> section are used by clients to configure
+ the user for client connections. In this example, clients connect to the broker as user <i>alice</i>.
+ </li>
+ <li>Pass the JAAS config file location as JVM parameter to each client JVM:
+ <pre> -Djava.security.auth.login.config=/etc/kafka/kafka_client_jaas.conf</pre></li>
+ <li>Configure the following properties in producer.properties or consumer.properties:
+ <pre> security.protocol=SASL_SSL
+ sasl.mechanism=PLAIN</pre></li>
+ </ol>
+ </li>
+ <li><h5><a id="security_sasl_plain_production" href="#security_sasl_plain_production">Use of SASL/PLAIN in production</a></h5>
<ul>
- <li>Incrementally bounce the cluster nodes to open additional secured port(s).</li>
- <li>Restart clients using the secured rather than PLAINTEXT port (assuming you are securing the client-broker connection).</li>
- <li>Incrementally bounce the cluster again to enable broker-to-broker security (if this is required)</li>
- <li>A final incremental bounce to close the PLAINTEXT port.</li>
+ <li>SASL/PLAIN should be used only with SSL as transport layer to ensure that clear passwords are not transmitted on the wire without encryption.</li>
+ <li>The default implementation of SASL/PLAIN in Kafka specifies usernames and passwords in the JAAS configuration file as shown
+ <a href="#security_sasl_plain_brokerconfig">here</a>. To avoid storing passwords on disk, you can plugin your own implementation of
+ <code>javax.security.auth.spi.LoginModule</code> that provides usernames and passwords from an external source. The login module implementation should
+ provide username as the public credential and password as the private credential of the <code>Subject</code>. The default implementation
+ <code>org.apache.kafka.common.security.plain.PlainLoginModule</code> can be used as an example.</li>
+ <li>In production systems, external authentication servers may implement password authentication. Kafka brokers can be integrated with these servers by adding
+ your own implementation of <code>javax.security.sasl.SaslServer</code>. The default implementation included in Kafka in the package
+ <code>org.apache.kafka.common.security.plain</code> can be used as an example to get started.
+ <ul>
+ <li>New providers must be installed and registered in the JVM. Providers can be installed by adding provider classes to
+ the normal <tt>CLASSPATH</tt> or bundled as a jar file and added to <tt><i>JAVA_HOME</i>/lib/ext</tt>.</li>
+ <li>Providers can be registered statically by adding a provider to the security properties file
+ <tt><i>JAVA_HOME</i>/lib/security/java.security</tt>.
+ <pre> security.provider.n=providerClassName</pre>
+ where <i>providerClassName</i> is the fully qualified name of the new provider and <i>n</i> is the preference order with
+ lower numbers indicating higher preference.</li>
+ <li>Alternatively, you can register providers dynamically at runtime by invoking <code>Security.addProvider</code> at the beginning of the client
+ application or in a static initializer in the login module. For example:
+ <pre> Security.addProvider(new PlainSaslServerProvider());</pre></li>
+ <li>For more details, see <a href="http://docs.oracle.com/javase/8/docs/technotes/guides/security/crypto/CryptoSpec.html">JCA Reference</a>.</li>
+ </ul>
+ </li>
</ul>
- <p></p>
- The specific steps for configuring SSL and SASL are described in sections <a href="#security_ssl">7.2</a> and <a href="#security_sasl">7.3</a>.
- Follow these steps to enable security for your desired protocol(s).
- <p></p>
- The security implementation lets you configure different protocols for both broker-client and broker-broker communication.
- These must be enabled in separate bounces. A PLAINTEXT port must be left open throughout so brokers and/or clients can continue to communicate.
- <p></p>
-
- When performing an incremental bounce stop the brokers cleanly via a SIGTERM. It's also good practice to wait for restarted replicas to return to the ISR list before moving onto the next node.
- <p></p>
- As an example, say we wish to encrypt both broker-client and broker-broker communication with SSL. In the first incremental bounce, a SSL port is opened on each node:
+ </li>
+ </ol>
+ </li>
+ <li><h4><a id="security_sasl_multimechanism" href="#security_sasl_multimechanism">Enabling multiple SASL mechanisms in a broker</a></h4>
+ <ol>
+ <li>Specify configuration for the login modules of all enabled mechanisms in the <tt>KafkaServer</tt> section of the JAAS config file. For example:
<pre>
+ KafkaServer {
+ com.sun.security.auth.module.Krb5LoginModule required
+ useKeyTab=true
+ storeKey=true
+ keyTab="/etc/security/keytabs/kafka_server.keytab"
+ principal="kafka/kafka1.hostname.com@EXAMPLE.COM";
+
+ org.apache.kafka.common.security.plain.PlainLoginModule required
+ username="admin"
+ password="admin-secret"
+ user_admin="admin-secret"
+ user_alice="alice-secret";
+ };</pre></li>
+ <li>Enable the SASL mechanisms in server.properties: <pre> sasl.enabled.mechanisms=GSSAPI,PLAIN</pre></li>
+ <li>Specify the SASL security protocol and mechanism for inter-broker communication in server.properties if required:
+ <pre> security.inter.broker.protocol=SASL_PLAINTEXT (or SASL_SSL)
+ sasl.mechanism.inter.broker.protocol=GSSAPI (or PLAIN)</pre></li>
+ <li>Follow the mechanism-specific steps in <a href="#security_sasl_kerberos_brokerconfig">GSSAPI (Kerberos)</a>
+ and <a href="#security_sasl_plain_brokerconfig">PLAIN</a> to configure SASL for the enabled mechanisms.</li>
+ </ol>
+ </li>
+ <li><h4><a id="security_rolling_upgrade" href="#security_rolling_upgrade">Incorporating Security Features in a Running Cluster</a></h4>
+ You can secure a running cluster via one or more of the supported protocols discussed previously. This is done in phases:
+ <p></p>
+ <ul>
+ <li>Incrementally bounce the cluster nodes to open additional secured port(s).</li>
+ <li>Restart clients using the secured rather than PLAINTEXT port (assuming you are securing the client-broker connection).</li>
+ <li>Incrementally bounce the cluster again to enable broker-to-broker security (if this is required)</li>
+ <li>A final incremental bounce to close the PLAINTEXT port.</li>
+ </ul>
+ <p></p>
+ The specific steps for configuring SSL and SASL are described in sections <a href="#security_ssl">7.2</a> and <a href="#security_sasl">7.3</a>.
+ Follow these steps to enable security for your desired protocol(s).
+ <p></p>
+ The security implementation lets you configure different protocols for both broker-client and broker-broker communication.
+ These must be enabled in separate bounces. A PLAINTEXT port must be left open throughout so brokers and/or clients can continue to communicate.
+ <p></p>
+
+ When performing an incremental bounce stop the brokers cleanly via a SIGTERM. It's also good practice to wait for restarted replicas to return to the ISR list before moving onto the next node.
+ <p></p>
+ As an example, say we wish to encrypt both broker-client and broker-broker communication with SSL. In the first incremental bounce, a SSL port is opened on each node:
+ <pre>
listeners=PLAINTEXT://broker1:9091,SSL://broker1:9092</pre>
- We then restart the clients, changing their config to point at the newly opened, secured port:
+ We then restart the clients, changing their config to point at the newly opened, secured port:
- <pre>
+ <pre>
bootstrap.servers = [broker1:9092,...]
security.protocol = SSL
...etc</pre>
- In the second incremental server bounce we instruct Kafka to use SSL as the broker-broker protocol (which will use the same SSL port):
+ In the second incremental server bounce we instruct Kafka to use SSL as the broker-broker protocol (which will use the same SSL port):
- <pre>
+ <pre>
listeners=PLAINTEXT://broker1:9091,SSL://broker1:9092
security.inter.broker.protocol=SSL</pre>
- In the final bounce we secure the cluster by closing the PLAINTEXT port:
+ In the final bounce we secure the cluster by closing the PLAINTEXT port:
- <pre>
+ <pre>
listeners=SSL://broker1:9092
security.inter.broker.protocol=SSL</pre>
- Alternatively we might choose to open multiple ports so that different protocols can be used for broker-broker and broker-client communication. Say we wished to use SSL encryption throughout (i.e. for broker-broker and broker-client communication) but we'd like to add SASL authentication to the broker-client connection also. We would achieve this by opening two additional ports during the first bounce:
+ Alternatively we might choose to open multiple ports so that different protocols can be used for broker-broker and broker-client communication. Say we wished to use SSL encryption throughout (i.e. for broker-broker and broker-client communication) but we'd like to add SASL authentication to the broker-client connection also. We would achieve this by opening two additional ports during the first bounce:
- <pre>
+ <pre>
listeners=PLAINTEXT://broker1:9091,SSL://broker1:9092,SASL_SSL://broker1:9093</pre>
- We would then restart the clients, changing their config to point at the newly opened, SASL & SSL secured port:
+ We would then restart the clients, changing their config to point at the newly opened, SASL & SSL secured port:
- <pre>
+ <pre>
bootstrap.servers = [broker1:9093,...]
security.protocol = SASL_SSL
...etc</pre>
- The second server bounce would switch the cluster to use encrypted broker-broker communication via the SSL port we previously opened on port 9092:
+ The second server bounce would switch the cluster to use encrypted broker-broker communication via the SSL port we previously opened on port 9092:
- <pre>
+ <pre>
listeners=PLAINTEXT://broker1:9091,SSL://broker1:9092,SASL_SSL://broker1:9093
security.inter.broker.protocol=SSL</pre>
- The final bounce secures the cluster by closing the PLAINTEXT port.
+ The final bounce secures the cluster by closing the PLAINTEXT port.
- <pre>
+ <pre>
listeners=SSL://broker1:9092,SASL_SSL://broker1:9093
security.inter.broker.protocol=SSL</pre>
- ZooKeeper can be secured independently of the Kafka cluster. The steps for doing this are covered in section <a href="#zk_authz_migration">7.5.2</a>.
- </li>
+ ZooKeeper can be secured independently of the Kafka cluster. The steps for doing this are covered in section <a href="#zk_authz_migration">7.5.2</a>.
+ </li>
+ <li><h4><a id="saslmechanism_rolling_upgrade" href="#saslmechanism_rolling_upgrade">Modifying SASL mechanism in a Running Cluster</a></h4>
+ <p>SASL mechanism can be modified in a running cluster using the following sequence:</p>
+ <ol>
+ <li>Enable new SASL mechanism by adding the mechanism to <tt>sasl.enabled.mechanisms</tt> in server.properties for each broker. Update JAAS config file to include both
+ mechanisms as described <a href="#security_sasl_multimechanism">here</a>. Incrementally bounce the cluster nodes.</li>
+ <li>Restart clients using the new mechanism.</li>
+ <li>To change the mechanism of inter-broker communication (if this is required), set <tt>sasl.mechanism.inter.broker.protocol</tt> in server.properties to the new mechanism and
+ incrementally bounce the cluster again.</li>
+ <li>To remove old mechanism (if this is required), remove the old mechanism from <tt>sasl.enabled.mechanisms</tt> in server.properties and remove the entries for the
+ old mechanism from JAAS config file. Incrementally bounce the cluster again.</li>
+ </ol>
+ </li>
</ol>
<h3><a id="security_authz" href="#security_authz">7.4 Authorization and ACLs</a></h3>