- name: Gather the package facts
package_facts:
manager: auto
tags:
- CCE-83621-3
- DISA-STIG-RHEL-09-611055
- accounts_password_pam_unix_rounds_system_auth
- configure_strategy
- low_complexity
- medium_disruption
- medium_severity
- no_reboot_needed
- name: XCCDF Value var_password_pam_unix_rounds # promote to variable
set_fact:
var_password_pam_unix_rounds: !!str <xccdf-1.2:sub xmlns:xccdf-1.2="http://checklists.nist.gov/xccdf/1.2" idref="xccdf_org.ssgproject.content_value_var_password_pam_unix_rounds" use="legacy"/>
tags:
- always
- name: Set number of Password Hashing Rounds - system-auth - Check if /etc/pam.d/system-auth
file is present
ansible.builtin.stat:
path: /etc/pam.d/system-auth
register: result_pam_file_present
when: '"pam" in ansible_facts.packages'
tags:
- CCE-83621-3
- DISA-STIG-RHEL-09-611055
- accounts_password_pam_unix_rounds_system_auth
- configure_strategy
- low_complexity
- medium_disruption
- medium_severity
- no_reboot_needed
- name: Set number of Password Hashing Rounds - system-auth - Check the proper remediation
for the system
block:
- name: Set number of Password Hashing Rounds - system-auth - Define the PAM file
to be edited as a local fact
ansible.builtin.set_fact:
pam_file_path: /etc/pam.d/system-auth
- name: Set number of Password Hashing Rounds - system-auth - Check if system relies
on authselect tool
ansible.builtin.stat:
path: /usr/bin/authselect
register: result_authselect_present
- name: Set number of Password Hashing Rounds - system-auth - Ensure authselect
custom profile is used if authselect is present
block:
- name: Set number of Password Hashing Rounds - system-auth - Check integrity
of authselect current profile
ansible.builtin.command:
cmd: authselect check
register: result_authselect_check_cmd
changed_when: false
failed_when: false
- name: Set number of Password Hashing Rounds - system-auth - Informative message
based on the authselect integrity check result
ansible.builtin.assert:
that:
- result_authselect_check_cmd.rc == 0
fail_msg:
- authselect integrity check failed. Remediation aborted!
- This remediation could not be applied because an authselect profile was
not selected or the selected profile is not intact.
- It is not recommended to manually edit the PAM files when authselect tool
is available.
- In cases where the default authselect profile does not cover a specific
demand, a custom authselect profile is recommended.
success_msg:
- authselect integrity check passed
- name: Set number of Password Hashing Rounds - system-auth - Get authselect current
profile
ansible.builtin.shell:
cmd: authselect current -r | awk '{ print $1 }'
register: result_authselect_profile
changed_when: false
when:
- result_authselect_check_cmd is success
- name: Set number of Password Hashing Rounds - system-auth - Define the current
authselect profile as a local fact
ansible.builtin.set_fact:
authselect_current_profile: '{{ result_authselect_profile.stdout }}'
authselect_custom_profile: '{{ result_authselect_profile.stdout }}'
when:
- result_authselect_profile is not skipped
- result_authselect_profile.stdout is match("custom/")
- name: Set number of Password Hashing Rounds - system-auth - Define the new authselect
custom profile as a local fact
ansible.builtin.set_fact:
authselect_current_profile: '{{ result_authselect_profile.stdout }}'
authselect_custom_profile: custom/hardening
when:
- result_authselect_profile is not skipped
- result_authselect_profile.stdout is not match("custom/")
- name: Set number of Password Hashing Rounds - system-auth - Get authselect current
features to also enable them in the custom profile
ansible.builtin.shell:
cmd: authselect current | tail -n+3 | awk '{ print $2 }'
register: result_authselect_features
changed_when: false
when:
- result_authselect_profile is not skipped
- authselect_current_profile is not match("custom/")
- name: Set number of Password Hashing Rounds - system-auth - Check if any custom
profile with the same name was already created
ansible.builtin.stat:
path: /etc/authselect/{{ authselect_custom_profile }}
register: result_authselect_custom_profile_present
changed_when: false
when:
- authselect_current_profile is not match("custom/")
- name: Set number of Password Hashing Rounds - system-auth - Create an authselect
custom profile based on the current profile
ansible.builtin.command:
cmd: authselect create-profile hardening -b {{ authselect_current_profile
}}
when:
- result_authselect_check_cmd is success
- authselect_current_profile is not match("custom/")
- not result_authselect_custom_profile_present.stat.exists
- name: Set number of Password Hashing Rounds - system-auth - Ensure authselect
changes are applied
ansible.builtin.command:
cmd: authselect apply-changes -b --backup=before-hardening-custom-profile
when:
- result_authselect_check_cmd is success
- result_authselect_profile is not skipped
- authselect_current_profile is not match("custom/")
- authselect_custom_profile is not match(authselect_current_profile)
- name: Set number of Password Hashing Rounds - system-auth - Ensure the authselect
custom profile is selected
ansible.builtin.command:
cmd: authselect select {{ authselect_custom_profile }}
register: result_pam_authselect_select_profile
when:
- result_authselect_check_cmd is success
- result_authselect_profile is not skipped
- authselect_current_profile is not match("custom/")
- authselect_custom_profile is not match(authselect_current_profile)
- name: Set number of Password Hashing Rounds - system-auth - Restore the authselect
features in the custom profile
ansible.builtin.command:
cmd: authselect enable-feature {{ item }}
loop: '{{ result_authselect_features.stdout_lines }}'
register: result_pam_authselect_restore_features
when:
- result_authselect_profile is not skipped
- result_authselect_features is not skipped
- result_pam_authselect_select_profile is not skipped
- name: Set number of Password Hashing Rounds - system-auth - Ensure authselect
changes are applied
ansible.builtin.command:
cmd: authselect apply-changes -b --backup=after-hardening-custom-profile
when:
- result_authselect_check_cmd is success
- result_authselect_profile is not skipped
- result_pam_authselect_restore_features is not skipped
- name: Set number of Password Hashing Rounds - system-auth - Change the PAM file
to be edited according to the custom authselect profile
ansible.builtin.set_fact:
pam_file_path: /etc/authselect/{{ authselect_custom_profile }}/{{ pam_file_path
| basename }}
when:
- result_authselect_present.stat.exists
- name: Set number of Password Hashing Rounds - system-auth - Check if expected
PAM module line is present in {{ pam_file_path }}
ansible.builtin.lineinfile:
path: '{{ pam_file_path }}'
regexp: ^\s*password\s+{{ 'sufficient' | regex_escape() }}\s+pam_unix.so\s*.*
state: absent
check_mode: true
changed_when: false
register: result_pam_line_present
- name: Set number of Password Hashing Rounds - system-auth - Include or update
the PAM module line in {{ pam_file_path }}
block:
- name: Set number of Password Hashing Rounds - system-auth - Check if required
PAM module line is present in {{ pam_file_path }} with different control
ansible.builtin.lineinfile:
path: '{{ pam_file_path }}'
regexp: ^\s*password\s+.*\s+pam_unix.so\s*
state: absent
check_mode: true
changed_when: false
register: result_pam_line_other_control_present
- name: Set number of Password Hashing Rounds - system-auth - Ensure the correct
control for the required PAM module line in {{ pam_file_path }}
ansible.builtin.replace:
dest: '{{ pam_file_path }}'
regexp: ^(\s*password\s+).*(\bpam_unix.so.*)
replace: \1sufficient \2
register: result_pam_module_edit
when:
- result_pam_line_other_control_present.found == 1
- name: Set number of Password Hashing Rounds - system-auth - Ensure the required
PAM module line is included in {{ pam_file_path }}
ansible.builtin.lineinfile:
dest: '{{ pam_file_path }}'
line: password sufficient pam_unix.so
register: result_pam_module_add
when:
- result_pam_line_other_control_present.found == 0 or result_pam_line_other_control_present.found
> 1
- name: Set number of Password Hashing Rounds - system-auth - Ensure authselect
changes are applied
ansible.builtin.command:
cmd: authselect apply-changes -b
when:
- result_authselect_present is defined
- result_authselect_present.stat.exists
- |-
(result_pam_module_add is defined and result_pam_module_add.changed)
or (result_pam_module_edit is defined and result_pam_module_edit.changed)
when:
- result_pam_line_present.found is defined
- result_pam_line_present.found == 0
- name: Set number of Password Hashing Rounds - system-auth - Check if the required
PAM module option is present in {{ pam_file_path }}
ansible.builtin.lineinfile:
path: '{{ pam_file_path }}'
regexp: ^\s*password\s+{{ 'sufficient' | regex_escape() }}\s+pam_unix.so\s*.*\srounds\b
state: absent
check_mode: true
changed_when: false
register: result_pam_module_rounds_option_present
- name: Set number of Password Hashing Rounds - system-auth - Ensure the "rounds"
PAM option for "pam_unix.so" is included in {{ pam_file_path }}
ansible.builtin.lineinfile:
path: '{{ pam_file_path }}'
backrefs: true
regexp: ^(\s*password\s+{{ 'sufficient' | regex_escape() }}\s+pam_unix.so.*)
line: \1 rounds={{ var_password_pam_unix_rounds }}
state: present
register: result_pam_rounds_add
when:
- result_pam_module_rounds_option_present.found == 0
- name: Set number of Password Hashing Rounds - system-auth - Ensure the required
value for "rounds" PAM option from "pam_unix.so" in {{ pam_file_path }}
ansible.builtin.lineinfile:
path: '{{ pam_file_path }}'
backrefs: true
regexp: ^(\s*password\s+{{ 'sufficient' | regex_escape() }}\s+pam_unix.so\s+.*)(rounds)=[0-9a-zA-Z]+\s*(.*)
line: \1\2={{ var_password_pam_unix_rounds }} \3
register: result_pam_rounds_edit
when:
- result_pam_module_rounds_option_present.found > 0
- name: Set number of Password Hashing Rounds - system-auth - Ensure authselect
changes are applied
ansible.builtin.command:
cmd: authselect apply-changes -b
when:
- result_authselect_present.stat.exists
- |-
(result_pam_rounds_add is defined and result_pam_rounds_add.changed)
or (result_pam_rounds_edit is defined and result_pam_rounds_edit.changed)
when:
- '"pam" in ansible_facts.packages'
- result_pam_file_present.stat.exists
tags:
- CCE-83621-3
- DISA-STIG-RHEL-09-611055
- accounts_password_pam_unix_rounds_system_auth
- configure_strategy
- low_complexity
- medium_disruption
- medium_severity
- no_reboot_needed
Remediation - Shell Script
# Remediation is applicable only in certain platforms
if rpm --quiet -q pam; then
var_password_pam_unix_rounds='<xccdf-1.2:sub xmlns:xccdf-1.2="http://checklists.nist.gov/xccdf/1.2" idref="xccdf_org.ssgproject.content_value_var_password_pam_unix_rounds" use="legacy"/>'
if [ -e "/etc/pam.d/system-auth" ] ; then
PAM_FILE_PATH="/etc/pam.d/system-auth"
if [ -f /usr/bin/authselect ]; then
if ! authselect check; then
echo "
authselect integrity check failed. Remediation aborted!
This remediation could not be applied because an authselect profile was not selected or the selected profile is not intact.
It is not recommended to manually edit the PAM files when authselect tool is available.
In cases where the default authselect profile does not cover a specific demand, a custom authselect profile is recommended."
exit 1
fi
CURRENT_PROFILE=$(authselect current -r | awk '{ print $1 }')
# If not already in use, a custom profile is created preserving the enabled features.
if [[ ! $CURRENT_PROFILE == custom/* ]]; then
ENABLED_FEATURES=$(authselect current | tail -n+3 | awk '{ print $2 }')
authselect create-profile hardening -b $CURRENT_PROFILE
CURRENT_PROFILE="custom/hardening"
authselect apply-changes -b --backup=before-hardening-custom-profile
authselect select $CURRENT_PROFILE
for feature in $ENABLED_FEATURES; do
authselect enable-feature $feature;
done
authselect apply-changes -b --backup=after-hardening-custom-profile
fi
PAM_FILE_NAME=$(basename "/etc/pam.d/system-auth")
PAM_FILE_PATH="/etc/authselect/$CURRENT_PROFILE/$PAM_FILE_NAME"
authselect apply-changes -b
fi
if ! grep -qP '^\s*password\s+'"sufficient"'\s+pam_unix.so\s*.*' "$PAM_FILE_PATH"; then
# Line matching group + control + module was not found. Check group + module.
if [ "$(grep -cP '^\s*password\s+.*\s+pam_unix.so\s*' "$PAM_FILE_PATH")" -eq 1 ]; then
# The control is updated only if one single line matches.
sed -i -E --follow-symlinks 's/^(\s*password\s+).*(\bpam_unix.so.*)/\1'"sufficient"' \2/' "$PAM_FILE_PATH"
else
echo 'password '"sufficient"' pam_unix.so' >> "$PAM_FILE_PATH"
fi
fi
# Check the option
if ! grep -qP '^\s*password\s+'"sufficient"'\s+pam_unix.so\s*.*\srounds\b' "$PAM_FILE_PATH"; then
sed -i -E --follow-symlinks '/\s*password\s+'"sufficient"'\s+pam_unix.so.*/ s/$/ rounds='"$var_password_pam_unix_rounds"'/' "$PAM_FILE_PATH"
else
sed -i -E --follow-symlinks 's/(\s*password\s+'"sufficient"'\s+pam_unix.so\s+.*)('"rounds"'=)[[:alnum:]]+\s*(.*)/\1\2'"$var_password_pam_unix_rounds"' \3/' "$PAM_FILE_PATH"
fi
if [ -f /usr/bin/authselect ]; then
authselect apply-changes -b
fi
else
echo "/etc/pam.d/system-auth was not found" >&2
fi
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi