Ensure Red Hat GPG Key Installed

Description

To ensure the system can cryptographically verify base software packages come from Red Hat (and to connect to the Red Hat Network to receive them), the Red Hat GPG key must properly be installed. To install the Red Hat GPG key, run:

$ sudo subscription-manager register

If the system is not connected to the Internet or an RHN Satellite, then install the Red Hat GPG key from trusted media such as the Red Hat installation CD-ROM or DVD. Assuming the disc is mounted in /media/cdrom, use the following command as the root user to import it into the keyring:

$ sudo rpm --import /media/cdrom/RPM-GPG-KEY

Alternatively, the key may be pre-loaded during the RHEL installation. In such cases, the key can be installed by running the following command:

sudo rpm --import /etc/pki/rpm-gpg/RPM-GPG-KEY-redhat-release

Rationale

Changes to software components can have significant effects on the overall security of the operating system. This requirement ensures the software has not been tampered with and that it has been provided by a trusted vendor. The Red Hat GPG key is necessary to cryptographically verify packages are from Red Hat.

Remediation

Shell script

The following script can be run on the host to remediate the issue.

#!/bin/bash

# The two fingerprints below are retrieved from https://access.redhat.com/security/team/key
readonly REDHAT_RELEASE_FINGERPRINT="567E347AD0044ADE55BA8A5F199E2F91FD431D51"
readonly REDHAT_AUXILIARY_FINGERPRINT="6A6AA7C97C8890AEC6AEBFE2F76F66C3D4082792"


# Location of the key we would like to import (once it's integrity verified)
readonly REDHAT_RELEASE_KEY="/etc/pki/rpm-gpg/RPM-GPG-KEY-redhat-release"

RPM_GPG_DIR_PERMS=$(stat -c %a "$(dirname "$REDHAT_RELEASE_KEY")")

# Verify /etc/pki/rpm-gpg directory permissions are safe
if [ "${RPM_GPG_DIR_PERMS}" -le "755" ]
then
  # If they are safe, try to obtain fingerprints from the key file
  # (to ensure there won't be e.g. CRC error).

  readarray -t GPG_OUT < <(gpg --show-keys --with-fingerprint --with-colons "$REDHAT_RELEASE_KEY" | grep -A1 "^pub" | grep "^fpr" | cut -d ":" -f 10)

  GPG_RESULT=$?
  # No CRC error, safe to proceed
  if [ "${GPG_RESULT}" -eq "0" ]
  then
  # If $REDHAT_RELEASE_KEY file doesn't contain any keys with unknown fingerprint, import it

    echo "${GPG_OUT[*]}" | grep -vE "${REDHAT_RELEASE_FINGERPRINT}|${REDHAT_AUXILIARY_FINGERPRINT}" || rpm --import "${REDHAT_RELEASE_KEY}"

  fi
fi

Ansible playbook

The following playbook can be run with Ansible to remediate the issue.

- name: 'Ensure Red Hat GPG Key Installed: Read permission of GPG key directory'
  ansible.builtin.stat:
    path: /etc/pki/rpm-gpg/
  register: gpg_key_directory_permission
  check_mode: false
  tags:
  - CCE-80795-8
  - CJIS-5.10.4.1
  - DISA-STIG-RHEL-08-010019
  - NIST-800-171-3.4.8
  - NIST-800-53-CM-5(3)
  - NIST-800-53-CM-6(a)
  - NIST-800-53-SC-12
  - NIST-800-53-SC-12(3)
  - NIST-800-53-SI-7
  - PCI-DSS-Req-6.2
  - PCI-DSSv4-6.3
  - PCI-DSSv4-6.3.3
  - ensure_redhat_gpgkey_installed
  - high_severity
  - medium_complexity
  - medium_disruption
  - no_reboot_needed
  - restrict_strategy

- name: 'Ensure Red Hat GPG Key Installed: Read signatures in GPG key'
  ansible.builtin.command: gpg --show-keys --with-fingerprint --with-colons "/etc/pki/rpm-gpg/RPM-GPG-KEY-redhat-release"
  changed_when: false
  register: gpg_fingerprints
  failed_when: false
  check_mode: false
  tags:
  - CCE-80795-8
  - CJIS-5.10.4.1
  - DISA-STIG-RHEL-08-010019
  - NIST-800-171-3.4.8
  - NIST-800-53-CM-5(3)
  - NIST-800-53-CM-6(a)
  - NIST-800-53-SC-12
  - NIST-800-53-SC-12(3)
  - NIST-800-53-SI-7
  - PCI-DSS-Req-6.2
  - PCI-DSSv4-6.3
  - PCI-DSSv4-6.3.3
  - ensure_redhat_gpgkey_installed
  - high_severity
  - medium_complexity
  - medium_disruption
  - no_reboot_needed
  - restrict_strategy

- name: 'Ensure Red Hat GPG Key Installed: Set Fact - Installed GPG Fingerprints'
  ansible.builtin.set_fact:
    gpg_installed_fingerprints: '{{ gpg_fingerprints.stdout | regex_findall(''^pub.*\n(?:^fpr[:]*)([0-9A-Fa-f]*)'',
      ''\1'') | list }}'
  tags:
  - CCE-80795-8
  - CJIS-5.10.4.1
  - DISA-STIG-RHEL-08-010019
  - NIST-800-171-3.4.8
  - NIST-800-53-CM-5(3)
  - NIST-800-53-CM-6(a)
  - NIST-800-53-SC-12
  - NIST-800-53-SC-12(3)
  - NIST-800-53-SI-7
  - PCI-DSS-Req-6.2
  - PCI-DSSv4-6.3
  - PCI-DSSv4-6.3.3
  - ensure_redhat_gpgkey_installed
  - high_severity
  - medium_complexity
  - medium_disruption
  - no_reboot_needed
  - restrict_strategy

- name: 'Ensure Red Hat GPG Key Installed: Set Fact - Valid fingerprints'
  ansible.builtin.set_fact:
    gpg_valid_fingerprints:
    - 567E347AD0044ADE55BA8A5F199E2F91FD431D51
    - 6A6AA7C97C8890AEC6AEBFE2F76F66C3D4082792
  tags:
  - CCE-80795-8
  - CJIS-5.10.4.1
  - DISA-STIG-RHEL-08-010019
  - NIST-800-171-3.4.8
  - NIST-800-53-CM-5(3)
  - NIST-800-53-CM-6(a)
  - NIST-800-53-SC-12
  - NIST-800-53-SC-12(3)
  - NIST-800-53-SI-7
  - PCI-DSS-Req-6.2
  - PCI-DSSv4-6.3
  - PCI-DSSv4-6.3.3
  - ensure_redhat_gpgkey_installed
  - high_severity
  - medium_complexity
  - medium_disruption
  - no_reboot_needed
  - restrict_strategy

- name: 'Ensure Red Hat GPG Key Installed: Import RedHat GPG key'
  ansible.builtin.command: rpm --import /etc/pki/rpm-gpg/RPM-GPG-KEY-redhat-release
  when:
  - gpg_key_directory_permission.stat.mode <= '0755'
  - (gpg_installed_fingerprints | difference(gpg_valid_fingerprints)) | length ==
    0
  - gpg_installed_fingerprints | length > 0
  - ansible_distribution == "RedHat"
  tags:
  - CCE-80795-8
  - CJIS-5.10.4.1
  - DISA-STIG-RHEL-08-010019
  - NIST-800-171-3.4.8
  - NIST-800-53-CM-5(3)
  - NIST-800-53-CM-6(a)
  - NIST-800-53-SC-12
  - NIST-800-53-SC-12(3)
  - NIST-800-53-SI-7
  - PCI-DSS-Req-6.2
  - PCI-DSSv4-6.3
  - PCI-DSSv4-6.3.3
  - ensure_redhat_gpgkey_installed
  - high_severity
  - medium_complexity
  - medium_disruption
  - no_reboot_needed
  - restrict_strategy