ansible-hardening/tasks/rhel7stig/sshd.yml

---
# Copyright 2016, Rackspace US, Inc.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

- name: Copy login warning banner
  copy:
    content: "{{ security_login_banner_text }}"
    dest: "{{ security_sshd_banner_file }}"
    owner: root
    group: root
    mode: "0644"
  tags:
    - high
    - sshd
    - V-71861
    - V-72225

- name: Drop options from SSH config that we manage
  lineinfile:
    path: /etc/ssh/sshd_config
    state: absent
    regexp: '^{{ item.name }}\s+(?!{{ item.value }})'
    validate: '/usr/sbin/sshd -T -f %s'
  with_items: "{{ sshd_settings_rhel7 | selectattr('enabled') }}"
  notify:
    - Restart ssh
  tags:
    - high
    - sshd
    - V-71939
    - V-71957
    - V-71959
    - V-72221
    - V-72225
    - V-72237
    - V-72241
    - V-72245
    - V-72247
    - V-72249
    - V-72243
    - V-72243
    - V-72303
    - V-72251
    - V-72253
    - V-72265
    - V-72267
    - V-72261
    - V-72263

- name: Adjust ssh server configuration based on STIG requirements
  blockinfile:
    dest: /etc/ssh/sshd_config
    state: present
    marker: "# {mark} MANAGED BY ANSIBLE-HARDENING"
    insertbefore: "BOF"
    validate: '/usr/sbin/sshd -T -f %s'
    block: |-
      {% set options = sshd_settings_rhel7 | selectattr('enabled') %}
      {% for option in options %}
      # {{ option['stig_id'] }}
      {{ option['name'] ~ ' ' ~ option['value'] }}
      {% endfor %}      
  notify:
    - Restart ssh
  tags:
    - high
    - sshd
    - V-71939
    - V-71957
    - V-71959
    - V-72221
    - V-72225
    - V-72237
    - V-72241
    - V-72245
    - V-72247
    - V-72249
    - V-72243
    - V-72243
    - V-72303
    - V-72251
    - V-72253
    - V-72265
    - V-72267
    - V-72261
    - V-72263

- name: Ensure sshd is enabled at boot time
  service:
    name: "{{ ssh_service }}"
    enabled: yes
  when:
    - security_enable_sshd | bool
  tags:
    - medium
    - sshd
    - V-72235

- name: Determine existing public ssh host keys
  shell: ls /etc/ssh/*.pub
  register: public_ssh_host_keys
  # The shell command will always report 'changed' so we need to
  # ignore that since this role is supposed to be idempotent.
  changed_when: false
  check_mode: no
  tags:
    - always

- name: Public host key files must have mode 0644 or less
  file:
    path: "{{ item }}"
    mode: "u-xX,g-wxs,o-wxt"
  with_items:
    - "{{ public_ssh_host_keys.stdout_lines | default([]) }}"
  tags:
    - medium
    - sshd
    - V-72255

- name: Determine existing private ssh host keys
  shell: ls /etc/ssh/*_key
  register: private_ssh_host_keys
  # The shell command will always report 'changed' so we need to
  # ignore that since this role is supposed to be idempotent
  changed_when: false
  check_mode: no
  tags:
    - always

- name: Private host key files must have mode 0600 or less
  file:
    path: "{{ item }}"
    mode: "u-xX,g-rwxs,o-rwxt"
  with_items:
    - "{{ private_ssh_host_keys.stdout_lines | default([]) }}"
  tags:
    - medium
    - sshd
    - V-72257

- name: Manage motd in pam.d
  replace:
    path: /etc/pam.d/sshd
    regexp: '^(#\s)?(session\s*optional\s*pam_motd.so.*)$'
    replace: '{{ (security_sshd_dynamic_banner_disable | bool) | ternary("# \2", "\2") }}'
  when: security_sshd_dynamic_banner_disable | bool