Better hardening-basic role

2022-11-21 12:56:57 +01:00 · 2022-11-21 12:56:57 +01:00 · 6a875bc851
commit 6a875bc851
parent 25f404da4e
7 changed files with 168 additions and 79 deletions
--- a/handbook.yml
+++ b/handbook.yml
@ -13,8 +13,10 @@
    - role: iptables-ipfs
      tags: [firewall, ipfs]

-    - fail2ban-basic
-    - hardening-basic
+    - role: fail2ban-basic
+      tags: [hardening]
+    - role: hardening-basic
+      tags: [hardening]
    - yggdrasil
    - role: snort-community
      tags: snort
--- a/roles/hardening-basic/defaults/main.yml
+++ b/roles/hardening-basic/defaults/main.yml
@ -2,11 +2,15 @@
 # defaults file for hardening-basic

 hardening_sshd_enabled: true
+hardening_sshd_port: 22
+hardening_sshd_authorized_key_file: .ssh/authorized_keys
 hardening_sshd_tcp_forward: false
+hardening_sshd_legal_banner: false
 hardening_sshd_permissions_set_sticky_bit: true

-hardening_modprobe_files:
-  - /etc/modprobe.d/disable-network-filesystems.conf
-  - /etc/modprobe.d/disable-rare-filesystems.conf
-  - /etc/modprobe.d/disable-rare-protocols.conf
-  - /etc/modprobe.d/disable-vivid.conf
+hardening_modprobe_disable_list:
+  ipv6: [ipv6]
+  network_filesystems: [cifs,nfs,nfsv3,nfsv4,gfs2]
+  rare_filesystems: [cramfs,freevxfs,jffs2,hfs,hfsplus,squashfs,udf]
+  rare_protocols: [dccp,sctp,rds,tipc,n-hdlc,ax25,netrom,x25,rose,decnet,econet,af_802154,ipx,appletalk,psnap,p8023,p8022,can,atm]
+  vivid: [vivid]
--- a/roles/hardening-basic/tasks/main.yml
+++ b/roles/hardening-basic/tasks/main.yml
@ -3,71 +3,33 @@

 - name: Basic Hardening
  block:
+    - name: Create and copy hardening files
+      ansible.builtin.template:
+        src: '{{ item.src }}'
+        dest: '/etc/{{ item.path }}'
+      with_community.general.filetree: '../templates/etc/'
+      when: item.state == 'file'
+
    - name: Harden SSH Config
      when: 'hardening_sshd_enabled is true'
      block:
-      - name: Check if sshd_config/99-hardening exists
-        stat:
-          path: /etc/ssh/sshd_config.d/99-hardening.conf
-        register: file_name

-      - name: Download sshd_config
-        when: not file_name.stat.exists
-        ansible.builtin.get_url:
-          url: https://git.unitoo.it/unitoo/configurations/raw/branch/master/ssh/etc/ssh/sshd_config
-          dest: /etc/ssh/sshd_config.d/99-hardening.conf
+        - name: Give 1700 permissions to .ssh folder
+          ansible.builtin.file:
+            path: /root/.ssh
+            owner: root
+            group: root
+            mode: "{{ '1' if hardening_sshd_permissions_set_sticky_bit }}700"

-      - name: Enable TCP SSH Forwarding
-        when: 'hardening_sshd_tcp_forward is true'
-        replace:
-          path: /etc/ssh/sshd_config.d/99-hardening.conf
-          regexp: 'AllowTcpForwarding no'
-          replace: 'AllowTcpForwarding yes'
-          backup: yes
+        - name: Give 1600 permissions to .ssh/authorized_keys file
+          ansible.builtin.file:
+            path: /root/.ssh/authorized_keys
+            owner: root
+            group: root
+            mode: "{{ '1' if hardening_sshd_permissions_set_sticky_bit }}600"

-      - name: Give 1700 permissions to .ssh folder
-        ansible.builtin.file:
-          path: /root/.ssh
-          owner: root
-          group: root
-          mode: "{{ '1' if hardening_sshd_permissions_set_sticky_bit }}700"
-
-      - name: Give 1600 permissions to .ssh/authorized_keys file
-        ansible.builtin.file:
-          path: /root/.ssh/authorized_keys
-          owner: root
-          group: root
-          mode: "{{ '1' if hardening_sshd_permissions_set_sticky_bit }}600"
-
-      - name: Restart sshd
-        when: "is_docker is not true"
-        ansible.builtin.systemd:
-          state: restarted
-          name: sshd
-
-    - name: Create if not exists /etc/modprobe.d
-      file:
-        path: /etc/modprobe.d
-        state: directory
-
-    - name: modprobe.d setup
-      include_tasks: modprobe.yml
-      loop: "{{ hardening_modprobe_files }}"
-      loop_control:
-        loop_var: file
-
-    - name: Create if not exists /etc/sysctl.d
-      file:
-        path: /etc/sysctl.d
-        state: directory
-
-    - name: Check if sysctl/99-hardening exists
-      stat:
-        path: /etc/sysctl.d/99-hardening.conf
-      register: file_name
-
-    - name: Download sysctl.conf
-      when: not file_name.stat.exists
-      ansible.builtin.get_url:
-        url: https://git.unitoo.it/unitoo/configurations/raw/branch/master/sysctl/etc/sysctl.conf
-        dest: /etc/sysctl.d/99-hardening.conf
+        - name: Restart sshd
+          when: "is_docker is not true"
+          ansible.builtin.systemd:
+            state: restarted
+            name: sshd
--- a/roles/hardening-basic/tasks/modprobe.yml
+++ b/roles/hardening-basic/tasks/modprobe.yml
@ -1,10 +0,0 @@
- name: Check if {{ file }} exists
-  stat:
-    path: "{{ file }}"
-  register: file_name
-
- name: Download {{ file }}
-  when: not file_name.stat.exists
-  ansible.builtin.get_url:
-    url: "https://git.unitoo.it/unitoo/configurations/raw/branch/master/modprobe/{{file}}"
-    dest: "{{ file }}"
--- a/roles/hardening-basic/templates/etc/modprobe.d/hardening.conf
+++ b/roles/hardening-basic/templates/etc/modprobe.d/hardening.conf
@ -0,0 +1,7 @@
+{% for section in hardening_modprobe_disable_list %}
+# Disable for {{ section }}
+{% for item in hardening_modprobe_disable_list[section] %}
+install {{ item }} /bin/false
+{% endfor %}
+
+{% endfor %}
--- a/roles/hardening-basic/templates/etc/ssh/sshd_config.d/99-hardening.conf
+++ b/roles/hardening-basic/templates/etc/ssh/sshd_config.d/99-hardening.conf
@ -0,0 +1,58 @@
+{% if hardening_sshd_enabled %}
+
+Protocol 2                                                      # Protocol 1 is fundamentally broken
+StrictModes yes                                                 # Protects from misconfiguration
+
+#ListenAddress [ip-here]                                        # Listening address
+Port {{ hardening_sshd_port }}                                  # Listening port. Normal 22
+
+AuthenticationMethods publickey                                 # Only public key authentication allowed
+AuthorizedKeysFile {{ hardening_sshd_authorized_key_file }}
+PubkeyAuthentication yes                                        # Allow public key authentication
+HostKey /etc/ssh/ssh_host_ed25519_key                           # Only allow ECDSA pubic key authentication
+HostKeyAlgorithms ssh-ed25519-cert-v01@openssh.com,ssh-ed25519  # Host keys the client should accepts
+KexAlgorithms curve25519-sha256                                 # Specifies the available KEX (Key Exchange) algorithms
+Ciphers chacha20-poly1305@openssh.com,aes256-gcm@openssh.com    # Specifies the ciphers allowed
+MACs hmac-sha2-512-etm@openssh.com                              # Specifies the available MAC alg.
+
+#Only allow incoming ECDSA and ed25519 sessions:
+HostbasedAcceptedKeyTypes ecdsa-sha2-nistp256,ecdsa-sha2-nistp384,ecdsa-sha2-nistp521,ssh-ed25519
+PubkeyAcceptedKeyTypes sk-ecdsa-sha2-nistp256@openssh.com,ecdsa-sha2-nistp256,ecdsa-sha2-nistp384,ecdsa-sha2-nistp521,sk-ssh-ed25519@openssh.com,ssh-ed25519
+#CASignatureAlgorithms ecdsa-sha2-nistp256,ecdsa-sha2-nistp384,ecdsa-sha2-nistp521,ssh-ed25519
+
+PermitRootLogin WITHOUT-PASSWORD                                # Enable/disable root login
+#AllowUsers [username]                                          # Authorized SSH users are inside the admin group
+MaxAuthTries 5                                                  # Maximum allowed authentication attempts
+MaxSessions 2                                                   # Maximum allowed sessions by the user
+
+PasswordAuthentication no                                       # No username password authentication
+PermitEmptyPasswords no                                         # No empty password authentcation allowed
+IgnoreRhosts yes                                                # Dont read users rhost files
+HostbasedAuthentication no                                      # Disable host-based authentication
+ChallengeResponseAuthentication no                              # Unused authentication scheme
+X11Forwarding no                                                # Disable X11 forwarding
+
+LogLevel VERBOSE                                                # Fingerprint details of failed login attempts
+SyslogFacility AUTH                                             # Logging authentication and authorization related commands
+UseDNS no                                                       # Client from a location without proper DNS generate a warning in the logs
+
+PermitTunnel no                                                 # Only SSH connection and nothing else
+AllowTcpForwarding {{ 'yes' if hardening_sshd_tcp_forward else 'no' }}                                          # Disablow tunneling out via SSH
+AllowStreamLocalForwarding no                                   # Disablow tunneling out via SSH
+GatewayPorts no                                                 # Disablow tunneling out via SSH
+AllowAgentForwarding no                                         # Do not allow agent forwarding
+
+{% if hardening_sshd_legal_banner %}
+Banner /etc/issue.net                                           # Show legal login banner
+{% endif %}
+PrintLastLog yes                                                # Show last login
+
+ClientAliveInterval 900                                         # Client timeout (15 minutes)
+ClientAliveCountMax 0                                           # This way enforces timeouts on the server side
+LoginGraceTime 30                                               # Authenticatin must happen within 30 seconds
+MaxStartups 2                                                   # Max concurrent SSH sessions
+TCPKeepAlive yes                                                # Do not use TCP keep-alive
+
+AcceptEnv LANG LC_*                                             # Allow client to pass locale environment variables
+
+{% endif %}
--- a/roles/hardening-basic/templates/etc/sysctl.d/99-hardening.conf
+++ b/roles/hardening-basic/templates/etc/sysctl.d/99-hardening.conf
@ -0,0 +1,66 @@
+# Hardened sysctl conf
+
+fs.protected_regular = 2
+fs.protected_fifos = 2
+fs.protected_hardlinks = 1
+fs.protected_symlinks = 1
+fs.suid_dumpable = 0
+
+kernel.core_uses_pid = 1
+kernel.ctrl-alt-del = 0
+kernel.dmesg_restrict = 1
+kernel.kptr_restrict = 2
+kernel.randomize_va_space = 2
+kernel.sysrq = 0
+kernel.unprivileged_bpf_disabled = 1
+
+
+net.core.bpf_jit_harden = 2
+net.ipv4.conf.all.accept_redirects = 0
+net.ipv4.conf.all.accept_source_route = 0
+net.ipv4.conf.all.bootp_relay = 0
+net.ipv4.conf.all.forwarding = 0
+net.ipv4.conf.all.log_martians = 1
+net.ipv4.conf.all.mc_forwarding = 0
+net.ipv4.conf.all.proxy_arp = 0
+net.ipv4.conf.all.rp_filter = 1
+net.ipv4.conf.all.send_redirects = 0
+net.ipv4.conf.all.secure_redirects=0
+net.ipv4.tcp_rfc1337=1
+net.ipv4.tcp_sack=0
+net.ipv4.tcp_dsack=0
+net.ipv4.tcp_fack=0
+
+net.ipv4.conf.default.accept_redirects = 0
+net.ipv4.conf.default.accept_source_route = 0
+net.ipv4.conf.default.log_martians = 1
+net.ipv4.conf.default.rp_filter=1
+net.ipv4.conf.default.send_redirects=0
+net.ipv4.conf.default.secure_redirects=0
+
+net.ipv4.icmp_echo_ignore_broadcasts = 1
+net.ipv4.icmp_ignore_bogus_error_responses = 1
+net.ipv4.tcp_syncookies = 1
+net.ipv4.tcp_timestamps = 1
+
+dev.tty.ldisc_autoload=0
+vm.unprivileged_userfaultfd=0
+kernel.kexec_load_disabled=1
+kernel.perf_event_paranoid=2
+kernel.yama.ptrace_scope=2
+
+vm.mmap_rnd_bits=32
+vm.mmap_rnd_compat_bits=16
+
+# Uncomment do disable ipv6
+#net.ipv6.conf.all.disable_ipv6=1
+#net.ipv6.conf.default.disable_ipv6=1
+#net.ipv6.conf.lo.disable_ipv6=1
+
+net.ipv6.conf.all.accept_redirects = 0
+net.ipv6.conf.all.accept_source_route = 0
+
+net.ipv6.conf.default.accept_redirects = 0
+net.ipv6.conf.default.accept_source_route = 0
+
+vm.swappiness = 15