fix(openvpn-phone): switch from static key to TLS peer-fingerprint

The Android client ships OpenVPN 2.7, which refuses a --secret config ("Options error: No tls-client or tls-server option"; 2.8 drops it entirely). Rework the phone instance to a CA-less TLS point-to-point: two self-signed EC keypairs generated on ru-vps (server.* / client.*), each side pins the other by SHA256 with peer-fingerprint, data-ciphers AES-256-GCM. Everything else unchanged (tcp/9444, tun2, 10.80.0.0/30, NAT via tun0, systemd unit, shared homelab_vpn_client_routes). Verified on ru-vps 2026-09-03: openvpn 2.6.19 starts clean ("Using certificate fingerprint to verify peer"), listens on 9444, tun2 up, make openvpn-phone idempotent (changed=0 on rerun), make lint green. The regenerated ansible/generated/ada-phone.ovpn (self-contained cert+key, gitignored) was handed to the operator. openvpn-laptop.yml is left on static key — not deployed; needs the same TLS treatment when someone actually uses it. Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01KbuZrUoevfBgCpf5DCF4DG
2026-09-03 09:44:19 +03:00
parent 4b54e44116
commit 1f27756afd
2 changed files with 160 additions and 34 deletions
@@ -2,21 +2,27 @@
 # ============================================================================
 # Road-warrior OpenVPN профиль для телефона (Android).
 #
-# Отдельный point-to-point static-key инстанс на ru-vps (порт 9444/tcp, tun2,
+# Отдельный TLS point-to-point инстанс на ru-vps (порт 9444/tcp, tun2,
 # сеть 10.80.0.0/30), параллельный тоннелю site-to-site (tun0, homelab-openvpn)
 # и профилю ноутбука (tun1, openvpn-laptop.yml). Клиент подключается один за
-# раз — static key не мультиплексируется.
+# раз.
+#
+# КРИПТО: peer-fingerprint, БЕЗ CA/PKI.
+#   На ru-vps генерятся две самоподписанные EC-пары (server.* и client.*),
+#   каждая сторона пинит другую по SHA256-отпечатку. Это «quick setup»
+#   из man-страницы OpenVPN 2.6+. Прежняя схема со static key (--secret)
+#   отброшена: OpenVPN 2.7 в Android-клиенте запускать её отказывается
+#   ("No tls-client or tls-server option"), а 2.8 уберёт совсем.
 #
 # КЛИЕНТ
-#   Приложение «OpenVPN for Android» (Arne Schwabe, F-Droid/Play). Официальный
-#   OpenVPN Connect static-key конфиги НЕ поддерживает — на Android нужен
-#   именно этот клиент.
+#   Android — «OpenVPN for Android» (Arne Schwabe) или OpenVPN Connect:
+#   TLS-конфиг понимают оба. Профиль самодостаточный (cert+key внутри).
 #
 # ЧТО ДЕЛАЕТ
-#   Ставит openvpn на ru-vps, генерит static key (один раз), открывает
+#   Ставит openvpn на ru-vps, генерит EC-пары (один раз), открывает
 #   9444/tcp в UFW, поднимает systemd-юнит homelab-openvpn-phone, NAT'ит
 #   10.80.0.0/30 -> LAN через tun0, кладёт готовый профиль в
-#   ansible/generated/ada-phone.ovpn (mode 0600, содержит секрет).
+#   ansible/generated/ada-phone.ovpn (mode 0600, содержит приватный ключ).
 #
 # ЗАПУСК
 #   make openvpn-phone
@@ -29,7 +35,10 @@
    phone_profile_name: ada-phone
    phone_openvpn_dir: /etc/openvpn/homelab-phone
    phone_openvpn_config: /etc/openvpn/homelab-phone/server.conf
-    phone_openvpn_key: /etc/openvpn/homelab-phone/static.key
+    phone_openvpn_server_cert: /etc/openvpn/homelab-phone/server.crt
+    phone_openvpn_server_key: /etc/openvpn/homelab-phone/server.key
+    phone_openvpn_client_cert: /etc/openvpn/homelab-phone/client.crt
+    phone_openvpn_client_key: /etc/openvpn/homelab-phone/client.key
    phone_openvpn_service: homelab-openvpn-phone
    phone_openvpn_port: 9444
    phone_openvpn_interface: tun2
@@ -38,6 +47,7 @@
    phone_openvpn_server_ip: 10.80.0.1
    phone_openvpn_client_ip: 10.80.0.2
    phone_openvpn_remote: 157.22.231.198
+    phone_openvpn_data_ciphers: "AES-256-GCM:AES-128-GCM"
    phone_openvpn_client_config_local: "{{ playbook_dir }}/../generated/{{ phone_profile_name }}.ovpn"
    phone_openvpn_routes: "{{ homelab_vpn_client_routes }}"

@@ -47,6 +57,7 @@
        name:
          - openvpn
          - iptables
+          - openssl
        state: present
        update_cache: true

@@ -58,12 +69,101 @@
        group: root
        mode: "0700"

-    - name: Generate phone static key if missing
-      ansible.builtin.command: "openvpn --genkey secret {{ phone_openvpn_key }}"
+    - name: Remove the obsolete static key (crypto model changed to TLS)
+      ansible.builtin.file:
+        path: "{{ phone_openvpn_dir }}/static.key"
+        state: absent
+
+    - name: Generate the server EC keypair if missing
+      ansible.builtin.command:
+        argv:
+          - openssl
+          - req
+          - -x509
+          - -newkey
+          - ec
+          - -pkeyopt
+          - ec_paramgen_curve:prime256v1
+          - -keyout
+          - "{{ phone_openvpn_server_key }}"
+          - -out
+          - "{{ phone_openvpn_server_cert }}"
+          - -nodes
+          - -sha256
+          - -days
+          - "3650"
+          - -subj
+          - /CN=homelab-phone-server
      args:
-        creates: "{{ phone_openvpn_key }}"
+        creates: "{{ phone_openvpn_server_cert }}"
      no_log: true

+    - name: Generate the client EC keypair if missing
+      ansible.builtin.command:
+        argv:
+          - openssl
+          - req
+          - -x509
+          - -newkey
+          - ec
+          - -pkeyopt
+          - ec_paramgen_curve:prime256v1
+          - -keyout
+          - "{{ phone_openvpn_client_key }}"
+          - -out
+          - "{{ phone_openvpn_client_cert }}"
+          - -nodes
+          - -sha256
+          - -days
+          - "3650"
+          - -subj
+          - /CN=homelab-phone-client
+      args:
+        creates: "{{ phone_openvpn_client_cert }}"
+      no_log: true
+
+    - name: Enforce key permissions
+      ansible.builtin.file:
+        path: "{{ item }}"
+        owner: root
+        group: root
+        mode: "0600"
+      loop:
+        - "{{ phone_openvpn_server_key }}"
+        - "{{ phone_openvpn_client_key }}"
+
+    - name: Read the server certificate fingerprint
+      ansible.builtin.command:
+        argv:
+          - openssl
+          - x509
+          - -in
+          - "{{ phone_openvpn_server_cert }}"
+          - -noout
+          - -fingerprint
+          - -sha256
+      register: phone_openvpn_server_fp_raw
+      changed_when: false
+
+    - name: Read the client certificate fingerprint
+      ansible.builtin.command:
+        argv:
+          - openssl
+          - x509
+          - -in
+          - "{{ phone_openvpn_client_cert }}"
+          - -noout
+          - -fingerprint
+          - -sha256
+      register: phone_openvpn_client_fp_raw
+      changed_when: false
+
+    - name: Extract the bare colon-separated fingerprints
+      # openssl печатает "sha256 Fingerprint=AB:CD:...", отпечаток без '='.
+      ansible.builtin.set_fact:
+        phone_openvpn_server_fp: "{{ phone_openvpn_server_fp_raw.stdout | regex_replace('^.*=', '') | trim }}"
+        phone_openvpn_client_fp: "{{ phone_openvpn_client_fp_raw.stdout | regex_replace('^.*=', '') | trim }}"
+
    - name: Enable IPv4 forwarding on ru-vps
      ansible.posix.sysctl:
        name: net.ipv4.ip_forward
@@ -85,16 +185,21 @@
        mode: "0600"
        content: |
          dev {{ phone_openvpn_interface }}
+          dev-type tun
          ifconfig {{ phone_openvpn_server_ip }} {{ phone_openvpn_client_ip }}
-          secret {{ phone_openvpn_key }}
-          cipher AES-256-CBC
-          auth SHA256
          proto tcp-server
          port {{ phone_openvpn_port }}
+          tls-server
+          dh none
+          cert {{ phone_openvpn_server_cert }}
+          key {{ phone_openvpn_server_key }}
+          peer-fingerprint {{ phone_openvpn_client_fp }}
+          data-ciphers {{ phone_openvpn_data_ciphers }}
+          auth SHA256
          persist-key
          persist-tun
-          verb 3
          keepalive 10 60
+          verb 3
      notify: restart phone openvpn

    - name: Render phone OpenVPN up script
@@ -156,10 +261,16 @@
        state: started
        enabled: true

-    - name: Read phone static key for client profile
+    - name: Read the client certificate for the profile
      ansible.builtin.slurp:
-        src: "{{ phone_openvpn_key }}"
-      register: phone_openvpn_static_key_raw
+        src: "{{ phone_openvpn_client_cert }}"
+      register: phone_openvpn_client_cert_raw
+      no_log: true
+
+    - name: Read the client key for the profile
+      ansible.builtin.slurp:
+        src: "{{ phone_openvpn_client_key }}"
+      register: phone_openvpn_client_key_raw
      no_log: true

    - name: Ensure local generated directory exists
@@ -177,12 +288,14 @@
        dest: "{{ phone_openvpn_client_config_local }}"
        mode: "0600"
        content: |
-          client
          dev tun
+          dev-type tun
          proto tcp-client
          remote {{ phone_openvpn_remote }} {{ phone_openvpn_port }}
          ifconfig {{ phone_openvpn_client_ip }} {{ phone_openvpn_server_ip }}
-          cipher AES-256-CBC
+          tls-client
+          peer-fingerprint {{ phone_openvpn_server_fp }}
+          data-ciphers {{ phone_openvpn_data_ciphers }}
          auth SHA256
          persist-key
          persist-tun
@@ -192,9 +305,12 @@
          {% for route in phone_openvpn_routes %}
          route {{ route.network }} {{ route.netmask }}
          {% endfor %}
-          <secret>
-          {{ phone_openvpn_static_key_raw.content | b64decode }}
-          </secret>
+          <cert>
+          {{ phone_openvpn_client_cert_raw.content | b64decode | trim }}
+          </cert>
+          <key>
+          {{ phone_openvpn_client_key_raw.content | b64decode | trim }}
+          </key>
      delegate_to: localhost
      vars:
        ansible_connection: local