Kafka 0.10.0 SASL/PLAIN身份认证及权限实现

本文主要介绍一下使用官方发布的 Kafka 0.10.0 版如何实现 SASL/PLAIN 认证机制以及权限控制。

Kafka 安全机制

Kafka 的安全机制主要分为两部分：

• 身份认证（Authentication）：对client 与服务器的连接进行身份认证。
• 权限控制（Authorization）：实现对于消息级别的权限控制

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:

1. 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.
2. Authentication of connections from brokers to ZooKeeper
3. 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.)
4. Authorization of read / write operations by clients
5. Authorization is pluggable and integration with external authorization services is supported

这段话的中文意思也就是说

1. 可以使用 SSL 或者 SASL 进行客户端（producer 和 consumer）、其他 brokers、tools与 brokers 之间连接的认证，SASL/PLAIN将在0.10.0中得到支持；
2. 对brokers和zookeeper之间的连接进行Authentication；
3. 数据传输用SSL加密，性能会下降；
4. 对clients的读写操作进行Authorization；
5. Authorization 是pluggable，与外部的authorization services结合进行支持。

Kafka身份认证

Kafka 目前支持SSL、SASL/Kerberos、SASL/PLAIN三种认证机制，关于这些认证机制的介绍可以参考一下三篇文章。

• 数字证书原理;
• 数字证书, 数字签名, SSL(TLS) , SASL;
• SSL的延迟

SASL/PLAIN 认证

可以参考kafka使用SASL验证，这个官方文档的中文版。

Kafka Server 端配置

需要在 Kafka 安装目录下的 config/server.properties 文件中配置以下信息

listeners=SASL_PLAINTEXT://ip:pot
security.inter.broker.protocol=SASL_PLAINTEXT
sasl.mechanism.inter.broker.protocol=PLAIN
sasl.enabled.mechanisms=PLAIN
authorizer.class.name = kafka.security.auth.SimpleAclAuthorizer
super.users=User:admin

如果要配置多个超级账户，可以按如下配置：

super.users=User:admin;User:alice

还需要配置一个名 kafka_server_jaas.conf 的配置文件，将配置文件放置在conf目录下。

KafkaServer {
    org.apache.kafka.common.security.plain.PlainLoginModule required
    username="admin"
    password="admin"
    user_admin="admin"
    user_alice="alice";
};

这里，我们配置了两个用户：admin 和 alice，密码分别为 admin 和 alice。
最后需要为 Kafka 添加 java.security.auth.login.config 环境变量。在 bin/kafka-run-class.sh 中添加以下内容

KAFKA_SASL_OPTS='-Djava.security.auth.login.config=/opt/meituan/kafka_2.10-0.10.0.0/config/kafka_server_jaas.conf'
# Launch mode
if [ "x$DAEMON_MODE" = "xtrue" ]; then
  nohup $JAVA $KAFKA_HEAP_OPTS $KAFKA_JVM_PERFORMANCE_OPTS $KAFKA_GC_LOG_OPTS $KAFKA_SASL_OPTS $KAFKA_JMX_OPTS $KAFKA_LOG4J_OPTS -cp $CLASSPATH $KAFKA_OPTS "$@" > "$CONSOLE_OUTPUT_FILE" 2>&1 < /dev/null &
else
  exec $JAVA $KAFKA_HEAP_OPTS $KAFKA_JVM_PERFORMANCE_OPTS $KAFKA_GC_LOG_OPTS $KAFKA_SASL_OPTS $KAFKA_JMX_OPTS $KAFKA_LOG4J_OPTS -cp $CLASSPATH $KAFKA_OPTS "$@"
fi

注：实际上，我们只是添加了第一行，并在第4和第6行中添加了 $KAFKA_SASL_OPTS 这个环境变量。

KafkaClient 配置

首先需要在客户端配置 kafka_client_jaas.conf 文件

KafkaClient {
  org.apache.kafka.common.security.plain.PlainLoginModule required
  username="alice"
  password="alice";
};

然后在（producer 和 consumer）程序中添加环境变量和配置，如下所示

System.setProperty("java.security.auth.login.config", ".../kafka_client_jaas.conf"); // 环境变量添加，需要输入配置文件的路径
props.put("security.protocol", "SASL_PLAINTEXT");
props.put("sasl.mechanism", "PLAIN");

配置完以上内容后，就可以正常运行 producer 和 consumer 程序，如果账户密码错误的话，程序就不能正常进行，但是不会有任何提示，这方面后面会进行一些改进。

Kafka权限控制

这个小节介绍一下 Kafka 的 ACL 。

权限的内容

权限	说明
READ	读取topic
WRITE	写入topic
DELETE	删除topic
CREATE	创建topic
ALTER	修改topic
DESCRIBE	获取topic的信息
ClusterAction
ALL	所有权限

访问控制列表ACL存储在zk上，路径为/kafka-acl。

权限配置

Kafka 提供的命令如下表所示

Option	Description	Default	Option type
–add	Indicates to the script that user is trying to add an acl.		Action
–remove	Indicates to the script that user is trying to remove an acl.		Action
–list	Indicates to the script that user is trying to list acts.		Action
–authorizer	Fully qualified class name of the authorizer.	kafka.security.auth.SimpleAclAuthorizer	Configuration
–authorizer-properties	key=val pairs that will be passed to authorizer for initialization. For the default authorizer the example values are: zookeeper.connect=localhost:2181		Configuration
–cluster	Specifies cluster as resource.		Resource
–topic [topic-name]	Specifies the topic as resource.		Resource
–group [group-name]	Specifies the consumer-group as resource.		Resource
–allow-principal	Principal is in PrincipalType:name format that will be added to ACL with Allow permission. You can specify multiple –allow-principal in a single command.		Principal
–deny-principal	Principal is in PrincipalType:name format that will be added to ACL with Deny permission. You can specify multiple –deny-principal in a single command.		Principal
–allow-host	IP address from which principals listed in –allow-principal will have access.	if –allow-principal is specified defaults to * which translates to “all hosts”	Host
–deny-host	IP address from which principals listed in –deny-principal will be denied access.	if –deny-principal is specified defaults to * which translates to “all hosts”	Host
–operation	Operation that will be allowed or denied. Valid values are : Read, Write, Create, Delete, Alter, Describe, ClusterAction, All	All	Operation
–producer	Convenience option to add/remove acls for producer role. This will generate acls that allows WRITE, DESCRIBE on topic and CREATE on cluster.		Convenience
–consumer	Convenience option to add/remove acls for consumer role. This will generate acls that allows READ, DESCRIBE on topic and READ on consumer-group.		Convenience

权限设置

通过几个例子介绍一下如何进行权限设置。

add 操作

# 为用户 alice 在 test（topic）上添加读写的权限
bin/kafka-acls.sh --authorizer-properties zookeeper.connect=data-rt-dev02:2181/kafka_test10 --add --allow-principal User:alice --operation Read --operation Write --topic test
# 对于 topic 为 test 的消息队列，拒绝来自 ip 为198.51.100.3账户为 BadBob  进行 read 操作，其他用户都允许
bin/kafka-acls.sh --authorizer-properties zookeeper.connect=data-rt-dev02:2181/kafka_test10 --add --allow-principal User:* --allow-host * --deny-principal User:BadBob --deny-host 198.51.100.3 --operation Read --topic test
# 为bob 和 alice 添加all，以允许来自 ip 为198.51.100.0或者198.51.100.1的读写请求
bin/kafka-acls.sh --authorizer-properties zookeeper.connect=data-rt-dev02:2181/kafka_test10 --add --allow-principal User:bob --allow-principal User:alice --allow-host 198.51.100.0 --allow-host 198.51.100.1 --operation Read --operation Write --topic test

list 操作

# 列出 topic 为 test 的所有权限账户
bin/kafka-acls.sh --authorizer-properties zookeeper.connect=data-rt-dev02:2181/kafka_test10 --list --topic test

输出信息为：

Current ACLs for resource `Topic:test`:
    User:alice has Allow permission for operations: Describe from hosts: *
    User:alice has Allow permission for operations: Read from hosts: *
    User:alice has Allow permission for operations: Write from hosts: *

remove 操作

# 移除 acl
bin/kafka-acls.sh --authorizer-properties zookeeper.connect=data-rt-dev02:2181/kafka_test10 --remove --allow-principal User:Bob --allow-principal User:Alice --allow-host 198.51.100.0 --allow-host 198.51.100.1 --operation Read --operation Write --topic test

producer 和 consumer 的操作

# producer
bin/kafka-acls.sh --authorizer-properties zookeeper.connect=data-rt-dev02:2181/kafka_test10 --add --allow-principal User:alice --producer --topic test

#consumer
bin/kafka-acls.sh --authorizer-properties zookeeper.connect=data-rt-dev02:2181/kafka_test10 --add --allow-principal User:alice --consumer --topic test —group test-group

填坑

本小节记录了在使用 SASL/PLAIN 时遇到的一些坑。

Controller连接broker失败

错误信息如下：

[2016-07-27 17:45:46,047] WARN [Controller-1-to-broker-1-send-thread], Controller 1's connection to broker XXXX:9092 (id: 1 rack: null) was unsuccessful (kafka.controller.RequestSendThread)
java.io.IOException: Connection to XXXX:9092 (id: 1 rack: null) failed
    at kafka.utils.NetworkClientBlockingOps$$anonfun$blockingReady$extension$2.apply(NetworkClientBlockingOps.scala:63)
    at kafka.utils.NetworkClientBlockingOps$$anonfun$blockingReady$extension$2.apply(NetworkClientBlockingOps.scala:59)
    at kafka.utils.NetworkClientBlockingOps$.recursivePoll$1(NetworkClientBlockingOps.scala:112)
    at kafka.utils.NetworkClientBlockingOps$.kafka$utils$NetworkClientBlockingOps$$pollUntil$extension(NetworkClientBlockingOps.scala:120)
    at kafka.utils.NetworkClientBlockingOps$.blockingReady$extension(NetworkClientBlockingOps.scala:59)
    at kafka.controller.RequestSendThread.brokerReady(ControllerChannelManager.scala:232)
    at kafka.controller.RequestSendThread.liftedTree1$1(ControllerChannelManager.scala:181)
    at kafka.controller.RequestSendThread.doWork(ControllerChannelManager.scala:180)
    at kafka.utils.ShutdownableThread.run(ShutdownableThread.scala:63)
[2016-07-27 17:45:46,056] INFO [delete-topics-thread-1], Starting  (kafka.controller.TopicDeletionManager$DeleteTopicsThread)
[2016-07-27 17:45:46,057] DEBUG [Topic Deletion Manager 1], Waiting for signal to start or continue topic deletion (kafka.controller.TopicDeletionManager)
[2016-07-27 17:45:46,351] WARN [Controller-1-to-broker-1-send-thread], Controller 1's connection to broker XXXX:9092 (id: 1 rack: null) was unsuccessful (kafka.controller.RequestSendThread)
java.io.IOException: Connection to XXXX:9092 (id: 1 rack: null) failed
    at kafka.utils.NetworkClientBlockingOps$$anonfun$blockingReady$extension$2.apply(NetworkClientBlockingOps.scala:63)
    at kafka.utils.NetworkClientBlockingOps$$anonfun$blockingReady$extension$2.apply(NetworkClientBlockingOps.scala:59)
    at kafka.utils.NetworkClientBlockingOps$.recursivePoll$1(NetworkClientBlockingOps.scala:112)
    at kafka.utils.NetworkClientBlockingOps$.kafka$utils$NetworkClientBlockingOps$$pollUntil$extension(NetworkClientBlockingOps.scala:120)
    at kafka.utils.NetworkClientBlockingOps$.blockingReady$extension(NetworkClientBlockingOps.scala:59)
    at kafka.controller.RequestSendThread.brokerReady(ControllerChannelManager.scala:232)
    at kafka.controller.RequestSendThread.liftedTree1$1(ControllerChannelManager.scala:181)
    at kafka.controller.RequestSendThread.doWork(ControllerChannelManager.scala:180)
    at kafka.utils.ShutdownableThread.run(ShutdownableThread.scala:63)

查找原因查找了半天，之前以为是kafka_server_jaas.conf文件的格式有问题，改了之后发现 Kafka 有时启动正常，有时不能正常启动，修改之前 conf 文件为：

KafkaServer {
    org.apache.kafka.common.security.plain.PlainLoginModule required
    username="admin"
    password="admin"
    user_matt=“33"
    user_alice="alice";
};

最后分析可能是因为没有在 user 中配置 admin 账户，因为 broker 之间也开启了身份认证，修改之后的配置文件如下。

KafkaServer {
    org.apache.kafka.common.security.plain.PlainLoginModule required
    username="admin"
    password="admin"
    user_admin="admin"
    user_alice="alice";
};

修改完之后，Kafka 就可以正常运行了。

---

参考：

• confluent的官网博客：Apache Kafka Security 101
• Kafka 官网：KIP-12 - Kafka Sasl/Kerberos and SSL implementation
• Kafka Security
• Kafka 官网：Kafka security
• Kafka 官网中文翻译kafka使用SASL验证