cluster security tls and cluster tlsciphersuite in Oracle RAC

 

The crsctl commands you provided are related to TLS (Transport Layer Security) configuration in Oracle Clusterware. 

TLS ensures secure communication between nodes in an Oracle Real Application Clusters (RAC) environment by encrypting network traffic and authenticating cluster components.

Here’s an explanation of each command:

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1. Command: crsctl get cluster security tls

• Purpose:

  • This command displays whether TLS encryption is enabled for inter-node communication in the Oracle Clusterware.

• Output:

  • The command typically returns one of the following values:
    • ON: TLS encryption is enabled for secure communication.
    • OFF: TLS encryption is not enabled (communication is unencrypted).
    • UNKNOWN: The cluster security status cannot be determined.

• What It Means:

• If ON, all network communication between the nodes in the cluster uses TLS for encryption and authentication.
• This ensures that sensitive data transmitted across nodes is secure.

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2. Command: crsctl get cluster tlsciphersuite

• Purpose:

  • This command retrieves the TLS cipher suite configured for Oracle Clusterware.

• Output:

  • Returns the specific cipher suite(s) used for TLS communication, such as:
    • Default cipher suites:
      • Examples: TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 or TLS_AES_256_GCM_SHA384.
    • Custom cipher suite:
      • If a custom cipher suite is configured, it will show that value.

• What It Means:

• The cipher suite defines the encryption algorithm and key exchange mechanism used for securing the communication.
• Oracle Clusterware supports a variety of strong ciphers (AES-based) to ensure security compliance.

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3. How These Commands Work Together

• crsctl get cluster security tls tells you if TLS encryption is enabled.
• crsctl get cluster tlsciphersuite specifies the algorithm used for the TLS encryption.

For example:

• If TLS is enabled (ON), the configured cipher suite determines how the encryption is implemented.
• If TLS is disabled (OFF), communication will not be encrypted, even if a cipher suite is specified.

• 
  

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4. How to Use This Information?

1. Check TLS Status:

   • Run crsctl get cluster security tls to verify if TLS is enabled for your Oracle RAC environment.
   • If it’s OFF, and your organization requires secure communication, enable it.

2. Verify Cipher Strength:

   • Run crsctl get cluster tlsciphersuite to review the cipher suite being used.
   • Ensure the cipher meets your organization's security policies (e.g., avoid weak ciphers).

3. Enable or Modify TLS Configuration:

• If needed, enable or change the TLS settings using the crsctl set command (see next section).

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5. Enabling or Configuring TLS

To enable or modify TLS in Oracle Clusterware, use the following commands:

Enable TLS:

crsctl set cluster security tls on

Set a Custom Cipher Suite:

crsctl set cluster tlsciphersuite <cipher_suite>

• Example:

  crsctl set cluster tlsciphersuite TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384

Restart Clusterware:

After enabling or modifying the settings, you may need to restart Oracle Clusterware for the changes to take effect:

crsctl stop crs
crsctl start crs

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6. Common Cipher Suites Supported by Oracle:

• Oracle supports several industry-standard cipher suites for TLS:
• TLS_AES_256_GCM_SHA384
• TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384
• TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256
• Ensure the selected cipher suite aligns with your organization's compliance and security standards.

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7. Verification

After making changes, verify the settings again:

• TLS Status:

  crsctl get cluster security tls

• Cipher Suite:

  crsctl get cluster tlsciphersuite

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Summary

• crsctl get cluster security tls checks if TLS is enabled for inter-node communication in Oracle Clusterware.
• crsctl get cluster tlsciphersuite retrieves the cipher suite used for encrypting TLS communication.
• Use these commands to ensure secure, encrypted communication in your RAC environment. Modify settings using the crsctl set commands as needed to comply with your security requirements.