Data at Rest Encryption Requirements

Encryption comprises several components, each with its own requirements.

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 Deployment Planning for Data at Rest Encryption.

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. Run the following commands on RHEL 6-compatible systems: 
$ sudo yum install rng-tools
$ sudo echo 'EXTRAOPTIONS="-r /dev/urandom"' >> /etc/sysconfig/rngd
$ sudo service rngd start
$ sudo chkconfig rngd on
For RHEL 7, run the following commands: 
$ sudo yum install rng-tools
$ cp /usr/lib/systemd/system/rngd.service /etc/systemd/system/
$ sed -i -e 's/ExecStart=\/sbin\/rngd -f/ExecStart=\/sbin\/rngd -f -r \/dev\/urandom/' /etc/systemd/system/rngd.service
$ systemctl daemon-reload
$ systemctl start rngd
$ systemctl enable rngd

Make sure that the hosts running Key Trustee Server, Key Trustee 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 Cloudera Navigator Key Trustee Server Compatibility Matrix.

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 Migrate Apache Web Server to CherryPy 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 Registration Options.

Key Trustee KMS Requirements

Recommended Hardware and Supported Distributions

The recommended minimum hardware specifications are as follows:

  • Processor: 2 GHz 64-bit quad core
  • Memory: 16 GB RAM
  • Storage: 40 GB on moderate- to high-performance disk drives

For information on the supported Linux distributions, see Key Trustee KMS Compatibility Matrix.

The Key Trustee 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.

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:
  • A supported Linux distribution. See Cloudera Navigator Key HSM Compatibility Matrix.
  • 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

Supported command-line interpreters:

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

Network Requirements

For new Navigator Key Trustee Server (5.4.0 and higher) installations, Navigator Encrypt initiates TCP traffic over port 11371 (HTTPS) to the Key Trustee Server.

For upgrades and Key Trustee Server versions lower than 5.4.0, 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.

Package Dependencies

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

  • dkms
  • keyutils
  • ecryptfs-utils
  • libkeytrustee
  • navencrypt-kernel-module
  • 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.