In the digital era, securing data in transit and at rest is paramount for any organization. Elasticsearch, a popular open-source search and analytics engine, is no exception. It’s widely used for log or event data analysis, full-text search, and complex queries. However, without proper security measures, sensitive data can be vulnerable to interception and unauthorized access. Enabling SSL/TLS (Transport Layer Security) in Elasticsearch is a crucial step in safeguarding your data.
This comprehensive guide outlines the steps to configure SSL/TLS, ensuring enhanced security for your Elasticsearch cluster.
Prerequisites
Before you begin, ensure you have the following:
- An Elasticsearch cluster set up and running.
- Administrative access to the Elasticsearch configuration files.
- A valid SSL/TLS certificate. You can obtain a certificate from a Certificate Authority (CA) or generate a self-signed certificate for testing purposes.
Step 1: Generate SSL/TLS Certificates
The first step is to generate SSL/TLS certificates for your Elasticsearch nodes. If you’re using self-signed certificates for testing, Elasticsearch’s elasticsearch-certutil tool can simplify this process. For production environments, it’s recommended to use certificates issued by a trusted CA.
- Create a Certificate Authority (CA): This step is crucial as it allows you to sign your Elasticsearch certificates. Elasticsearch provides a tool called elasticsearch-certutil for this purpose.
./bin/elasticsearch-certutil caWhen prompted for the name of CA file, hit enter to use default or set a new name.
- Generate SSL Certificate for Elasticsearch: Using the CA created, now generate a certificate specifically for your Elasticsearch node(s).
./bin/elasticsearch-certutil cert --ca elastic-stack-ca.p12Replace elastic-stack-ca.p12 with the actual path where your CA certificate stored. This command produces a .p12 (PKCS#12) file, encapsulating the node’s certificate, private key, and the CA certificate. You might need to generate specific certificates for each node in your cluster, depending on your setup.
Step 2: Configure Elasticsearch to Use SSL Certificate
Once you have your SSL/TLS certificates, you need to configure Elasticsearch to use them. This involves editing the elasticsearch.yml configuration file on each node in your cluster.
Add the following configurations to elasticsearch.yml on each node:
xpack.security.enabled: true
xpack.security.transport.ssl.enabled: true
xpack.security.transport.ssl.verification_mode: certificate
xpack.security.transport.ssl.client_authentication: required
xpack.security.transport.ssl.keystore.path: elastic-certificates.p12
xpack.security.transport.ssl.truststore.path: elastic-certificates.p12
xpack.security.http.ssl.enabled: true
xpack.security.http.ssl.keystore.path: elastic-certificates.p12
xpack.security.http.ssl.truststore.path: elastic-certificates.p12
Replace “elastic-certificates.p12” with your certificate file name as created in previous step.
Step 3: Restart Elasticsearch
After configuring all nodes, restart your Elasticsearch cluster to apply the changes. Ensure that the cluster starts without errors and that all nodes can communicate with each other over SSL/TLS.
Step 4: Verify SSL/TLS Configuration
To verify that SSL/TLS is enabled and working correctly, use a tool like curl to make a request to the Elasticsearch HTTP API:
curl -k https://localhost:9200
The -k option allows curl to connect without certificate verification, which is useful for initial testing with self-signed certificates. If everything is configured correctly, you should receive a JSON response from Elasticsearch.
Conclusion
Securing your Elasticsearch cluster with SSL/TLS is a critical step in protecting your data. By following the steps outlined in this guide, you can ensure that your data remains secure in transit, mitigating potential risks of data interception or tampering. Always remember to use certificates from trusted CAs for production environments to ensure the highest level of security and trust.
