6.11 Ensure the pgcrypto extension is installed and configured correctly

Information

PostgreSQL must implement cryptographic mechanisms to prevent unauthorized disclosure or modification of organization-defined information at rest (to include, at a minimum, PII and classified information) on organization-defined information system components.

Rationale:

PostgreSQL instances handling data that requires 'data at rest' protections must employ cryptographic mechanisms to prevent unauthorized disclosure and modification of the information at rest. These cryptographic mechanisms may be native to PostgreSQL or implemented via additional software or operating system/file system settings, as appropriate to the situation. Information at rest refers to the state of information when it is located on a secondary storage device (e.g. disk drive, tape drive) within an organizational information system.

The selection of a cryptographic mechanism is based on the need to protect the integrity of organizational information. The strength of the mechanism is commensurate with the security category and/or classification of the information. Organizations have the flexibility to either encrypt all information on storage devices (i.e. full disk encryption) or encrypt specific data structures (e.g. files, records, or fields). Organizations may also optionally choose to implement both to implement layered security.

The decision of whether, and what, to encrypt rests with the data owner and is also influenced by the physical measures taken to secure the equipment and media on which the information resides. Organizations may choose to employ different mechanisms to achieve confidentiality and integrity protection, as appropriate. If the confidentiality and integrity of application data are not protected, the data will be open to compromise and unauthorized modification.

The PostgreSQL pgcrypto extension provides cryptographic functions for PostgreSQL and is intended to address the confidentiality and integrity of user and system information at rest in non-mobile devices.

Impact:

When considering or undertaking any form of encryption, it is critical to understand the state of the encrypted data at all stages of the data lifecycle. The use of pgcrypto ensures that the data at rest in the tables (and therefore on disk) is encrypted, but for the data to be accessed by any users or applications, said users/applications will, by necessity, have access to the encrypt and decrypt keys and the data in question will be encrypted/decrypted in memory and then transferred to/from the user/application in that form.

Solution

The pgcrypto extension is included with the PostgreSQL 'contrib' package. Although included, it needs to be created in the database.
As the database administrator, run the following:

postgres=# CREATE EXTENSION pgcrypto;
CREATE EXTENSION

Verify pgcrypto is installed:

postgres=# SELECT * FROM pg_available_extensions WHERE name='pgcrypto';
name | default_version | installed_version | comment
----------+-----------------+-------------------+-------------------------
pgcrypto | 1.3 | 1.3 | cryptographic functions
(1 row)

See Also

https://workbench.cisecurity.org/benchmarks/17004

Item Details

Category: IDENTIFICATION AND AUTHENTICATION, SYSTEM AND COMMUNICATIONS PROTECTION

References: 800-53|IA-5(1), 800-53|SC-28, 800-53|SC-28(1), CSCv7|14.8

Plugin: PostgreSQLDB

Control ID: 825967a605ef3c5502c7cd51d8a9ebdd8de4254ad8729ffaa62f29c19b3ce09a