|Finding ID||Version||Rule ID||IA Controls||Severity|
|Operating systems handling data requiring "data at rest" protections must employ cryptographic mechanisms to prevent unauthorized disclosure and modification of the information at rest. 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).|
|Canonical Ubuntu 20.04 LTS Security Technical Implementation Guide||2022-12-06|
|Check Text ( C-41575r654268_chk )|
| If there is a documented and approved reason for not having data-at-rest encryption, this requirement is Not Applicable. |
Verify the Ubuntu operating system prevents unauthorized disclosure or modification of all information requiring at-rest protection by using disk encryption.
Determine the partition layout for the system with the following command:
$ sudo fdisk -l
Disk /dev/vda: 15 GiB, 16106127360 bytes, 31457280 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disklabel type: gpt
Disk identifier: 83298450-B4E3-4B19-A9E4-7DF147A5FEFB
Device Start End Sectors Size Type
/dev/vda1 2048 4095 2048 1M BIOS boot
/dev/vda2 4096 2101247 2097152 1G Linux filesystem
/dev/vda3 2101248 31455231 29353984 14G Linux filesystem
Verify that the system partitions are all encrypted with the following command:
$ more /etc/crypttab
Every persistent disk partition present must have an entry in the file.
If any partitions other than the boot partition or pseudo file systems (such as /proc or /sys) are not listed, this is a finding.
|Fix Text (F-41534r654269_fix)|
| To encrypt an entire partition, dedicate a partition for encryption in the partition layout. |
Note: Encrypting a partition in an already-installed system is more difficult because it will need to be resized and existing partitions changed.