Ansible-Bootstrap/roles/cis/tasks/main.yml

---
- name: Configurationg System for CIS conformity
  block:
    - name: Disable Kernel Modules
      ansible.builtin.copy:
        dest: /mnt/etc/modprobe.d/cis.conf
        mode: '0644'
        content: |
          CIS LVL 3 Restrictions
          install freevxfs        /bin/true
          install jffs2           /bin/true
          install hfs             /bin/true
          install hfsplus         /bin/true
          install squashfs        /bin/true
          install udf             /bin/true
          install usb-storage     /bin/true

          install dccp            /bin/true
          install sctp            /bin/true
          install rds             /bin/true
          install tipc            /bin/true

    - name: Create USB Rules
      ansible.builtin.copy:
        dest: /mnt/etc/udev/rules.d/10-cis_usb_devices.sh
        mode: '0644'
        content: |
          By default, disable all.
          ACTION=="add", SUBSYSTEMS=="usb", TEST=="authorized_default", ATTR{authorized_default}="0"

          Enable hub devices.
          ACTION=="add", ATTR{bDeviceClass}=="09", TEST=="authorized", ATTR{authorized}="1"

          Enables keyboard devices
          ACTION=="add", ATTR{product}=="*[Kk]eyboard*", TEST=="authorized", ATTR{authorized}="1"

          PS2-USB converter
          ACTION=="add", ATTR{product}=="*Thinnet TM*", TEST=="authorized", ATTR{authorized}="1"

    - name: Create a consolidated sysctl configuration file
      ansible.builtin.copy:
        dest: /mnt/etc/sysctl.d/10-cis.conf
        mode: '0644'
        content: |
          ## CIS Sysctl configurations
          net.ipv4.conf.all.log_martians = 1
          net.ipv4.conf.all.rp_filter = 1
          net.ipv4.conf.all.secure_redirects = 0
          net.ipv4.conf.all.send_redirects = 0
          net.ipv4.conf.all.accept_redirects = 0
          net.ipv4.conf.default.log_martians = 1
          net.ipv4.conf.default.rp_filter = 1
          net.ipv4.conf.default.secure_redirects = 0
          net.ipv4.conf.default.send_redirects = 0
          net.ipv4.conf.default.accept_redirects = 0
          net.ipv6.conf.all.accept_redirects = 0
          net.ipv6.conf.all.disable_ipv6 = 1
          net.ipv6.conf.default.accept_redirects = 0
          net.ipv6.conf.default.disable_ipv6 = 1
          net.ipv6.conf.lo.disable_ipv6 = 1

    # - name: Adjust login.defs
    #   replace:
    #     path: /mnt/etc/login.defs
    #     regexp: "{{ item.regexp }}"
    #     replace: "{{ item.replace }}"
    #   loop:
    #     - { regexp: '^PASS_MAX_DAYS.*', replace: 'PASS_MAX_DAYS 90' }
    #     - { regexp: '^PASS_MIN_DAYS.*', replace: 'PASS_MIN_DAYS 7' }
    #     - { regexp: '^UMASK.*', replace: 'UMASK           027' }

    - name: Ensure files exist
      ansible.builtin.file:
        path: "{{ item }}"
        state: touch
        mode: "0600"
      loop:
        - /mnt/etc/at.allow
        - /mnt/etc/cron.allow
        - /mnt/etc/hosts.allow
        - /mnt/etc/hosts.deny

    - name: Add Security related lines into config files
      ansible.builtin.lineinfile:
        path: "{{ item.path }}"
        line: "{{ item.content }}"
      loop:
        - { path: /mnt/etc/security/limits.conf, content: "* hard core 0" }
        - { path: /mnt/etc/security/pwquality.conf, content: minlen = 14 }
        - { path: /mnt/etc/security/pwquality.conf, content: dcredit = -1 }
        - { path: /mnt/etc/security/pwquality.conf, content: ucredit = -1 }
        - { path: /mnt/etc/security/pwquality.conf, content: ocredit = -1 }
        - { path: /mnt/etc/security/pwquality.conf, content: lcredit = -1 }
        - { path: '/mnt/etc/{{ "bashrc" if os in ["almalinux", "fedora", "rocky"] else "bash.bashrc" }}', content: umask 077 }
        - { path: '/mnt/etc/{{ "bashrc" if os in ["almalinux", "fedora", "rocky"] else "bash.bashrc" }}', content: export TMOUT=3000 }
        - { path: '/mnt/{{ "usr/lib/systemd/journald.conf" if os == "fedora" else "etc/systemd/journald.conf" }}', content: Storage=persistent }
        - { path: /mnt/etc/sudoers, content: Defaults        logfile="/var/log/sudo.log" }
        - { path: /mnt/etc/pam.d/su, content: auth required pam_wheel.so }
        - { path: '/mnt/etc/{{ "pam.d/common-auth" if os in ["debian11", "debian12", "ubuntu", "ubuntu-lts"]
            else "authselect/system-auth" if os == "fedora" else "pam.d/system-auth" }}',
            content: auth required pam_faillock.so onerr=fail audit silent deny=5 unlock_time=900 }
        - { path: '/mnt/etc/{{ "pam.d/common-account" if os in ["debian11", "debian12", "ubuntu", "ubuntu-lts"] else "authselect/system-auth"
            if os == "fedora" else "pam.d/system-auth" }}', content: account required pam_faillock.so }
        - { path: '/mnt/etc/pam.d/{{ "common-password" if os in ["debian11", "debian12", "ubuntu", "ubuntu-lts"] else "passwd" }}',
            content: "password [success=1 default=ignore] pam_unix.so obscure sha512 remember=5" }
        - { path: /mnt/etc/hosts.deny, content: "ALL: ALL" }
        - { path: /mnt/etc/hosts.allow, content: "sshd: ALL" }

    - name: Set permissions for various files and directories
      ansible.builtin.file:
        path: "{{ item.path }}"
        owner: "{{ item.owner | default(omit) }}"
        group: "{{ item.group | default(omit) }}"
        mode: "{{ item.mode }}"
      loop:
        - { path: /mnt/etc/ssh/sshd_config, mode: "0600" }
        - { path: /mnt/etc/cron.hourly, mode: "0700" }
        - { path: /mnt/etc/cron.daily, mode: "0700" }
        - { path: /mnt/etc/cron.weekly, mode: "0700" }
        - { path: /mnt/etc/cron.monthly, mode: "0700" }
        - { path: /mnt/etc/cron.d, mode: "0700" }
        - { path: /mnt/etc/crontab, mode: "0600" }
        - { path: /mnt/etc/logrotate.conf, mode: "0644" }
        - { path: /mnt/usr/sbin/pppd, mode: "754" }
        - { path: '/mnt/usr/bin/{{ "fusermount3" if os in ["archlinux", "debian12", "fedora", "rocky", "almalinux"] else "fusermount" }}', mode: "755" }
        - { path: '/mnt/usr/bin/{{ "write.ul" if os == "debian11" else "write" }}', mode: "755" }

    - name: Adjust SSHD config
      ansible.builtin.lineinfile:
        path: /mnt/etc/ssh/sshd_config
        regexp: ^\s*#?{{ item.option }}\s+.*$
        line: "{{ item.option }} {{ item.value }}"
      with_items:
        - { option: LogLevel, value: VERBOSE }
        - { option: LoginGraceTime, value: "60" }
        - { option: PermitRootLogin, value: "no" }
        - { option: StrictModes, value: "yes" }
        - { option: MaxAuthTries, value: "4" }
        - { option: MaxSessions, value: "10" }
        - { option: MaxStartups, value: 10:30:60 }
        - { option: PubkeyAuthentication, value: "yes" }
        - { option: HostbasedAuthentication, value: "no" }
        - { option: IgnoreRhosts, value: "yes" }
        - { option: PasswordAuthentication, value: "no" }
        - { option: PermitEmptyPasswords, value: "no" }
        - { option: KerberosAuthentication, value: "no" }
        - { option: GSSAPIAuthentication, value: "no" }
        - { option: GSSAPIKeyExchange, value: "no" }
        - { option: AllowAgentForwarding, value: "no" }
        - { option: AllowTcpForwarding, value: "no" }
        - { option: ChallengeResponseAuthentication, value: "no" }
        - { option: GatewayPorts, value: "no" }
        - { option: X11Forwarding, value: "no" }
        - { option: PermitUserEnvironment, value: "no" }
        - { option: ClientAliveInterval, value: "300" }
        - { option: ClientAliveCountMax, value: "0" }
        - { option: PermitTunnel, value: "no" }
        - { option: Banner, value: /etc/issue.net }

    - name: Append CIS Specific configurations to sshd_config
      ansible.builtin.lineinfile:
        path: /mnt/etc/ssh/sshd_config
        line: |2-

          ## CIS Specific
          Protocol 2

          ### Ciphers and keying ###
          RekeyLimit 512M 6h
          KexAlgorithms curve25519-sha256,curve25519-sha256@libssh.org,diffie-hellman-group14-sha256,diffie-hellman-group16-sha512,diffie-hellman-group18-sha512,ecdh-sha2-nistp521,ecdh-sha2-nistp384,ecdh-sha2-nistp256,diffie-hellman-group-exchange-sha256
          Ciphers chacha20-poly1305@openssh.com,aes256-gcm@openssh.com,aes128-gcm@openssh.com,aes256-ctr,aes192-ctr,aes128-ctr
          MACs hmac-sha2-512-etm@openssh.com,hmac-sha2-256-etm@openssh.com,hmac-sha2-512,hmac-sha2-256
          ###########################

          AllowStreamLocalForwarding no
          PermitUserRC no

          AllowUsers *
          AllowGroups *
          DenyUsers nobody
          DenyGroups nobody