Cloudera Docs

Data at Rest Encryption Requirements

Encryption comprises several components, each with its own requirements.

Overview

Data at rest encryption protection can be applied at a number of levels within Hadoop:

  • OS filesystem-level
  • Network-level
  • HDFS-level (protects both data at rest and in transit)

For more information on the components, concepts, and architecture for encrypting data at rest, see "Encrypting Data at Rest".

Product Compatibility Matrix

See "Product Compatibility Matrix for Cloudera Navigator Encryption" for the individual compatibility matrices for each Cloudera Navigator encryption component.

Entropy Requirements

Cryptographic operations require entropy to ensure randomness.

You can check the available entropy on a Linux system by running the following command:
cat /proc/sys/kernel/random/entropy_avail

The output displays the entropy currently available. Check the entropy several times to determine the state of the entropy pool on the system. If the entropy is consistently low (500 or less), you must increase it by installing rng-tools and starting the rngd service.

For RHEL 7, run the following commands:
sudo yum install rng-tools
cp /usr/lib/systemd/system/rngd.service /etc/systemd/system/
systemctl daemon-reload
systemctl start rngd
systemctl enable rngd

Make sure that the hosts running Key Trustee Server, Ranger KMS, and Navigator Encrypt have sufficient entropy to perform cryptographic operations.

Key Trustee Server Requirements

Recommended Hardware and Supported Distributions

Key Trustee Server must be installed on a dedicated server or virtual machine (VM) that is not used for any other purpose. The backing PostgreSQL database must be installed on the same host as the Key Trustee Server, and must not be shared with any other services. For high availability, the active and passive Key Trustee Servers must not share physical resources. See "Resource Planning for Data at Rest Encryption" for more information.

The recommended minimum hardware specifications are as follows:

  • Processor: 1 GHz 64-bit quad core
  • Memory: 8 GB RAM
  • Storage: 20 GB on moderate- to high-performance disk drives

For information on the supported Linux distributions, see "Product Compatibility Matrix for Cloudera Navigator Encryption".

Cloudera Manager Requirements

Installing and managing Key Trustee Server using Cloudera Manager requires Cloudera Manager 5.4.0 and higher. Key Trustee Server does not require Cloudera Navigator Audit Server or Metadata Server.

umask Requirements

Key Trustee Server installation requires the default umask of 0022.

Network Requirements

For new Key Trustee Server installations (5.4.0 and higher) and migrated upgrades (see "Cloudera Enterprise Upgrade Guide"> for more information), Key Trustee Server requires the following TCP ports to be opened for inbound traffic:

  • 11371

    Clients connect to this port over HTTPS.

  • 11381 (PostgreSQL)

    The passive Key Trustee Server connects to this port for database replication.

For upgrades that are not migrated to the CherryPy web server, the pre-upgrade port settings are preserved:

  • 80

    Clients connect to this port over HTTP to obtain the Key Trustee Server public key.

  • 443 (HTTPS)

    Clients connect to this port over HTTPS.

  • 5432 (PostgreSQL)

    The passive Key Trustee Server connects to this port for database replication.

TLS Certificate Requirements

To ensure secure network traffic, Cloudera recommends obtaining Transport Layer Security (TLS) certificates specific to the hostname of your Key Trustee Server. To obtain the certificate, generate a Certificate Signing Request (CSR) for the fully qualified domain name (FQDN) of the Key Trustee Server host. The CSR must be signed by a trusted Certificate Authority (CA). After the certificate has been verified and signed by the CA, the Key Trustee Server TLS configuration requires:

  • The CA-signed certificate
  • The private key used to generate the original CSR
  • The intermediate certificate/chain file (provided by the CA)

Cloudera recommends not using self-signed certificates. If you use self-signed certificates, you must use the --skip-ssl-check parameter when registering Navigator Encrypt with the Key Trustee Server. This skips TLS hostname validation, which safeguards against certain network-level attacks. For more information regarding insecure mode, see "Registering Cloudera Navigator Encrypt with Key Trustee Server>Registration Options".

Ranger KMS Requirements

Recommended Hardware and Supported Distributions

The recommended minimum hardware specifications are as follows:

  • Processor: 1 GHz 64-bit quad core
  • Memory: 8 GB RAM
  • Storage: 20 GB on moderate- to high-performance disk drives

For information on the supported Linux distributions, see "Product Compatibility Matrix for Cloudera Navigator Encryption".

The Ranger KMS workload is CPU-intensive. Cloudera recommends using machines with capabilities equivalent to your NameNode hosts, with Intel CPUs that support AES-NI for optimum performance. Also, Cloudera strongly recommends that you enable TLS for both the HDFS and the Ranger services to prevent the passage of plain text key material between the KMS and HDFS data nodes.

Key HSM Requirements

The following are prerequisites for installing Navigator Key HSM:

  • Oracle Java Runtime Environment (JRE) 7 or higher with Java Cryptography Extension (JCE) Unlimited Strength Jurisdiction Policy Files:
    • JCE for Java SE 7
    • JCE for Java SE 8
  • A supported Linux distribution. See "Product Compatibility Matrix for Cloudera Navigator Encryption".
  • A supported HSM device:
    • SafeNet Luna
      • HSM firmware version: 6.2.1
      • HSM software version: 5.2.3-1
    • SafeNet KeySecure
      • HSM firmware version: 6.2.1
      • HSM software version: 8.0.1
    • Thales nSolo, nConnect
      • HSM firmware version: 11.4.0
      • Client software version: 2.28.9cam136
  • Key Trustee Server 3.8 or higher

Root access is required to install Navigator Key HSM.

Navigator Encrypt Requirements

Operating System Requirements

  • For supported Linux distributions, see "Product Compatibility Matrix for Cloudera Navigator Encryption".

Supported command-line interpreters:

  • sh (Bourne)
  • bash (Bash)
  • dash (Debian)

Network Requirements

For new Navigator Key Trustee Server installations, Navigator Encrypt initiates TCP traffic over port 11371 (HTTPS) to the Key Trustee Server.

For new Ranger KMS installations, Navigator Encrypt initiates TCP traffic over port 9494 (HTTPS) to Ranger KMS.

For upgrades, Navigator Encrypt initiates TCP traffic over ports 80 (HTTP) and 443 (HTTPS) to the Navigator Key Trustee Server.

Internet Access

You must have an active connection to the Internet to download many package dependencies, unless you have internal repositories or mirrors containing the dependent packages.

Maintenance Window

Data is not accessible during the encryption process. Plan for system downtime during installation and configuration.

Administrative Access

To enforce a high level of security, all Navigator Encrypt commands require administrative (root) access (including installation and configuration). If you do not have administrative privileges on your server, contact your system administrator before proceeding.

Network Time Protocol (NTP)

The Network Time Protocol (NTP) service synchronizes system time. Cloudera recommends using NTP to ensure that timestamps in system logs, cryptographic signatures, and other auditable events are consistent across systems.

Package Dependencies

Navigator Encrypt requires these packages, which are resolved by your distribution package manager during installation:

  • dkms
  • keyutils
  • openssl
  • lsof
  • gcc
  • cryptsetup

These packages may have other dependencies that are also resolved by your package manager. Installation works with gcc, gcc3, and gcc4.