Merge pull request #7 from jhampson-dbre/6-harden-ssh

Add role to harden os

roles/harden_os/README.md

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+harden_os
+=========
+
+Improve security of Debian 10 OS running Home Assistant Supervised on Raspberry Pi 4
+
+This role can perform the following hardening:
+
+1. Harden SSH
+
+  - Disable root SSH login
+  - Disable SSH password authentication
+  - Only allow SSH key authentication
+
+1. Enable Automatic Security Updates
+
+  - Install and configure unattended-upgrades
+
+
+Requirements
+------------
+
+This role must be ran as the root user or with `become` enabled.
+
+Additional considerations:
+
+- Harden SSH
+
+  You should ensure that you have a non-root user with sudo priviledges and an SSH key configured before running this role. This can be completed accomplished by running the `jhampson_dbre.home_assistant.preinstall_config` role that is available in the collection.
+
+- Automatic Security Updates
+
+  If automatic reboots are enabled, ensure the time is set correctly on the Raspberry Pi to ensure reboots happen at the expectd time.
+
+Role Variables
+--------------
+
+The following variables are set in `defaults/main.yml`
+
+```yaml
+# Lock down SSH, including disabling SSH root log in
+harden_ssh: true
+
+# Configure automatic installation of security updates
+enable_automatic_security_updates: true
+
+## Automatic Security Patching options
+
+# Reboot automatically if reboot is required for installed patches
+enable_patching_reboot: "true"
+
+# The time to reboot at if automatic reboot is enabled
+patching_reboot_time: "04:00"
+```
+
+Dependencies
+------------
+
+none
+
+Example Playbook
+----------------
+
+```yaml
+
+- hosts: pi
+  roles:
+     - role: jhampson_dbre.home_assistant.harden_os
+```
+
+License
+-------
+
+MIT
+
+Author Information
+------------------
+
+@jhampson-dbre

roles/harden_os/defaults/main.yml

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+---
+# Configure which areas to harden
+harden_ssh: true
+enable_automatic_security_updates: true
+
+# Automatic Security Patching options
+enable_patching_reboot: "true"
+patching_reboot_time: "04:00"

roles/harden_os/handlers/main.yml

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+---
+- name: restart sshd
+  service:
+    name: sshd
+    state: restarted

roles/harden_os/meta/main.yml

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+galaxy_info:
+  author: Jared Hampson
+  description: Improve OS security after Home Assistant Suprvised is installed
+
+  license: MIT
+
+  min_ansible_version: 2.9
+
+  platforms:
+    - name: Debian
+      versions:
+        - buster
+
+  galaxy_tags:
+    - home
+    - assistant
+    - supervised
+    - raspberry
+    - pi
+    - hassio
+
+dependencies: []

roles/harden_os/tasks/main.yml

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+---
+- name: import ssh tasks
+  import_task: ssh.yml
+  when: harden_ssh|bool
+
+- name: import patching tasks
+  import_task: patching.yml
+  when: enable_automatic_security_updates|bool

roles/harden_os/tasks/patching.yml

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+---
+- name: install unattended-upgrades package
+  apt:
+    name:
+      - unattended-upgrades
+      - apt-listchanges
+    state: present
+
+- name: Ensure the apt auto-upgrades configuration stub is created
+  shell: >
+    echo unattended-upgrades unattended-upgrades/enable_auto_updates boolean true
+     | debconf-set-selections
+
+    dpkg-reconfigure -f noninteractive unattended-upgrades
+  args:
+    warn: no
+
+- name: Configure unattended upgrades
+  template:
+    src: 50unattended-upgrades.j2
+    dest: /etc/apt/apt.conf.d/50unattended-upgrades
+    owner: root
+    group: root
+    mode: '0644'

roles/harden_os/tasks/ssh.yml

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+---
+- name: Harden SSH
+  block:
+    - name: Disable root SSH login
+      lineinfile:
+        path: /etc/ssh/sshd_config
+        regexp: '^PermitRootLogin'
+        line: 'PermitRootLogin no'
+        state: present
+        validate: /usr/sbin/sshd -T -f %s
+
+    - name: Disable SSH password authentication
+      lineinfile:
+        path: /etc/ssh/sshd_config
+        regexp: '^PasswordAuthentication'
+        line: 'PasswordAuthentication no'
+        state: present
+        validate: /usr/sbin/sshd -T -f %s
+
+    - name: Enable sandbox for SSH privilege seperation
+      lineinfile:
+        path: /etc/ssh/sshd_config
+        regex: '^UsePrivilegeSeparation'
+        line: 'UsePrivilegeSeparation sandbox'
+        state: present
+        validate: /usr/sbin/sshd -T -f %s
+
+    - name: Only allow SSH key authentication
+      lineinfile:
+        path: /etc/ssh/sshd_config
+        regex: '^AuthenticationMethods'
+        line: 'AuthenticationMethods publickey'
+        state: present
+        validate: /usr/sbin/sshd -T -f %s
+  notify:
+    - restart sshd

roles/harden_os/templates/50unattended-upgrades.j2

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+// Automatically upgrade packages from these (origin:archive) pairs
+//
+// Note that in Ubuntu security updates may pull in new dependencies
+// from non-security sources (e.g. chromium). By allowing the release
+// pocket these get automatically pulled in.
+Unattended-Upgrade::Allowed-Origins {
+        "${distro_id}:${distro_codename}";
+        "${distro_id}:${distro_codename}-security";
+        // Extended Security Maintenance; doesn't necessarily exist for
+        // every release and this system may not have it installed, but if
+        // available, the policy for updates is such that unattended-upgrades
+        // should also install from here by default.
+        "${distro_id}ESMApps:${distro_codename}-apps-security";
+        "${distro_id}ESM:${distro_codename}-infra-security";
+//      "${distro_id}:${distro_codename}-updates";
+//      "${distro_id}:${distro_codename}-proposed";
+//      "${distro_id}:${distro_codename}-backports";
+};
+
+// Python regular expressions, matching packages to exclude from upgrading
+Unattended-Upgrade::Package-Blacklist {
+    // The following matches all packages starting with linux-
+//  "linux-";
+
+    // Use $ to explicitely define the end of a package name. Without
+    // the $, "libc6" would match all of them.
+//  "libc6$";
+//  "libc6-dev$";
+//  "libc6-i686$";
+
+    // Special characters need escaping
+//  "libstdc\+\+6$";
+
+    // The following matches packages like xen-system-amd64, xen-utils-4.1,
+    // xenstore-utils and libxenstore3.0
+//  "(lib)?xen(store)?";
+
+    // For more information about Python regular expressions, see
+    // https://docs.python.org/3/howto/regex.html
+};
+
+// This option controls whether the development release of Ubuntu will be
+// upgraded automatically. Valid values are "true", "false", and "auto".
+Unattended-Upgrade::DevRelease "false";
+
+// This option allows you to control if on a unclean dpkg exit
+// unattended-upgrades will automatically run
+//   dpkg --force-confold --configure -a
+// The default is true, to ensure updates keep getting installed
+//Unattended-Upgrade::AutoFixInterruptedDpkg "true";
+
+// Split the upgrade into the smallest possible chunks so that
+// they can be interrupted with SIGTERM. This makes the upgrade
+// a bit slower but it has the benefit that shutdown while a upgrade
+// is running is possible (with a small delay)
+//Unattended-Upgrade::MinimalSteps "true";
+
+// Install all updates when the machine is shutting down
+// instead of doing it in the background while the machine is running.
+// This will (obviously) make shutdown slower.
+// Unattended-upgrades increases logind's InhibitDelayMaxSec to 30s.
+// This allows more time for unattended-upgrades to shut down gracefully
+// or even install a few packages in InstallOnShutdown mode, but is still a
+// big step back from the 30 minutes allowed for InstallOnShutdown previously.
+// Users enabling InstallOnShutdown mode are advised to increase
+// InhibitDelayMaxSec even further, possibly to 30 minutes.
+//Unattended-Upgrade::InstallOnShutdown "false";
+
+// Send email to this address for problems or packages upgrades
+// If empty or unset then no email is sent, make sure that you
+// have a working mail setup on your system. A package that provides
+// 'mailx' must be installed. E.g. "[email protected]"
+//Unattended-Upgrade::Mail "";
+
+// Set this value to one of:
+//    "always", "only-on-error" or "on-change"
+// If this is not set, then any legacy MailOnlyOnError (boolean) value
+// is used to chose between "only-on-error" and "on-change"
+//Unattended-Upgrade::MailReport "on-change";
+
+// Remove unused automatically installed kernel-related packages
+// (kernel images, kernel headers and kernel version locked tools).
+//Unattended-Upgrade::Remove-Unused-Kernel-Packages "true";
+
+// Do automatic removal of newly unused dependencies after the upgrade
+//Unattended-Upgrade::Remove-New-Unused-Dependencies "true";
+
+// Do automatic removal of unused packages after the upgrade
+// (equivalent to apt-get autoremove)
+Unattended-Upgrade::Remove-Unused-Dependencies "true";
+
+// Automatically reboot *WITHOUT CONFIRMATION* if
+//  the file /var/run/reboot-required is found after the upgrade
+Unattended-Upgrade::Automatic-Reboot "{{ patching_reboot_enabled }}";
+
+// Automatically reboot even if there are users currently logged in
+// when Unattended-Upgrade::Automatic-Reboot is set to true
+//Unattended-Upgrade::Automatic-Reboot-WithUsers "true";
+
+// If automatic reboot is enabled and needed, reboot at the specific
+// time instead of immediately
+//  Default: "now"
+Unattended-Upgrade::Automatic-Reboot-Time "{{ patching_reboot_time }}";
+
+// Use apt bandwidth limit feature, this example limits the download
+// speed to 70kb/sec
+//Acquire::http::Dl-Limit "70";
+
+// Enable logging to syslog. Default is False
+// Unattended-Upgrade::SyslogEnable "false";
+
+// Specify syslog facility. Default is daemon
+// Unattended-Upgrade::SyslogFacility "daemon";
+
+// Download and install upgrades only on AC power
+// (i.e. skip or gracefully stop updates on battery)
+// Unattended-Upgrade::OnlyOnACPower "true";
+
+// Download and install upgrades only on non-metered connection
+// (i.e. skip or gracefully stop updates on a metered connection)
+// Unattended-Upgrade::Skip-Updates-On-Metered-Connections "true";
+
+// Verbose logging
+// Unattended-Upgrade::Verbose "false";
+
+// Print debugging information both in unattended-upgrades and
+// in unattended-upgrade-shutdown
+// Unattended-Upgrade::Debug "false";
+
+// Allow package downgrade if Pin-Priority exceeds 1000
+// Unattended-Upgrade::Allow-downgrade "false";

roles/harden_os/tests/inventory

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+localhost
+

roles/harden_os/tests/test.yml

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+---
+- hosts: localhost
+  remote_user: root
+  roles:
+    - harden_os