public-health-ch/ansible/roles/dev-sec.ssh-hardening/tasks/main.yml

---
- name: Set OS dependent variables
  include_vars: "{{ item }}"
  with_first_found:
   - "{{ ansible_distribution }}_{{ ansible_distribution_major_version }}.yml"
   - "{{ ansible_distribution }}.yml"
   - "{{ ansible_os_family }}_{{ ansible_distribution_major_version }}.yml"
   - "{{ ansible_os_family }}.yml"

- name: get openssh-version
  shell: ssh -V 2>&1 | sed -r 's/.*_([0-9]*\.[0-9]).*/\1/g'
  changed_when: false
  register: sshd_version

- name: set hostkeys according to openssh-version
  set_fact:
    ssh_host_key_files: ['/etc/ssh/ssh_host_rsa_key']
  when: sshd_version.stdout >= '5.3'

- name: set hostkeys according to openssh-version
  set_fact:
    ssh_host_key_files: ['/etc/ssh/ssh_host_rsa_key', '/etc/ssh/ssh_host_ecdsa_key']
  when: sshd_version.stdout >= '6.0'

- name: set hostkeys according to openssh-version
  set_fact:
    ssh_host_key_files: ['/etc/ssh/ssh_host_rsa_key', '/etc/ssh/ssh_host_ecdsa_key', '/etc/ssh/ssh_host_ed25519_key']
  when: sshd_version.stdout >= '6.3'

- name: create sshd_config and set permissions to root/600
  template: src='opensshd.conf.j2' dest='/etc/ssh/sshd_config' mode=0600 owner="{{ ssh_owner }}" group="{{ ssh_group }}" validate="/usr/sbin/sshd -T -f %s"
  notify: restart sshd
  when: ssh_server_hardening

- name: create ssh_config and set permissions to root/644
  template: src='openssh.conf.j2' dest='/etc/ssh/ssh_config' mode=0644 owner="{{ ssh_owner }}" group="{{ ssh_group }}"
  when: ssh_client_hardening

- name: Check if /etc/ssh/moduli contains weak DH parameters
  shell: awk '$5 < {{ sshd_moduli_minimum }}' /etc/ssh/moduli
  register: sshd_register_moduli
  changed_when: false
  check_mode: no

- name: remove all small primes
  shell: awk '$5 >= {{ sshd_moduli_minimum }}' /etc/ssh/moduli > /etc/ssh/moduli.new ;
         [ -r /etc/ssh/moduli.new -a -s /etc/ssh/moduli.new ] && mv /etc/ssh/moduli.new /etc/ssh/moduli || true
  notify: restart sshd
  when: sshd_register_moduli.stdout

- name: test to see if selinux is running
  command: getenforce
  register: sestatus
  failed_when: false
  changed_when: false
  check_mode: no

- block: # only runs when selinux is running
  - name: install selinux dependencies when selinux is installed on RHEL or Oracle Linux
    yum: name="{{item}}" state=installed
    with_items:
      - policycoreutils-python
      - checkpolicy
    when: ansible_os_family == 'RedHat' or ansible_os_family == 'Oracle Linux'

  - name: install selinux dependencies when selinux is installed on Debian or Ubuntu
    apt: name="{{item}}" state=installed
    with_items:
      - policycoreutils
      - checkpolicy
    when: ansible_distribution == 'Debian' or ansible_distribution == 'Ubuntu'

  - name: check if ssh_password module is already installed
    shell: "semodule -l| grep ssh_password"
    register: ssh_password_module
    failed_when: false
    changed_when: false
    check_mode: no

  # The following tasks only get executed when selinux is in state enforcing, UsePam is "no" and the ssh_password module is installed.
  # See this issue for more info: https://github.com/hardening-io/ansible-ssh-hardening/issues/23
  - block:
    - name: Create selinux custom policy drop folder
      file: path='{{ ssh_custom_selinux_dir }}' state=directory owner=root group=root mode=0750

    - name: Distributing custom selinux policies
      copy: src='ssh_password' dest='{{ ssh_custom_selinux_dir }}'

    - name: check and compile policy
      shell: checkmodule -M -m -o {{ ssh_custom_selinux_dir }}/ssh_password.mod {{ ssh_custom_selinux_dir }}/ssh_password

    - name: create selinux policy module package
      shell: semodule_package -o {{ ssh_custom_selinux_dir }}/ssh_password.pp  -m {{ ssh_custom_selinux_dir }}/ssh_password.mod

    - name: install selinux policy
      shell: semodule -i {{ ssh_custom_selinux_dir }}/ssh_password.pp

    when: not ssh_use_pam and sestatus.stdout != 'Disabled' and ssh_password_module.stdout.find('ssh_password') != 0

  # The following tasks only get executed when selinux is in state enforcing, UsePam is "yes" and the ssh_password module is installed.
  - name: remove selinux-policy when Pam is used, because Allowing sshd to read the shadow file directly is considered a potential security risk (http://danwalsh.livejournal.com/12333.html)
    shell: semodule -r ssh_password
    when: ssh_use_pam and ssh_password_module.stdout.find('ssh_password') == 0

  when: sestatus.rc == 0