fix: use DNS validation for managed TLS certificate

remote-access/README.md

@@ -45,6 +45,14 @@ npm run remote:start
 
 ## 服务器管理
 
+首次配置 `ck.yydd.ai` 的正式证书时，管理员需在服务器创建 `/etc/cangku-tls/cloudflare.ini`，内容为 Cloudflare 最小权限 API Token：
+
+```ini
+dns_cloudflare_api_token = <仅 DNS 编辑权限的 Token>
+```
+
+文件权限必须为 `0600`、所有者为 root。然后以 root 依次运行 `provision-certificate.sh` 和 `install.sh`；Certbot 会使用 DNS-01 验证并由系统定时器自动续期。该文件绝不能提交到 Git。
+
 服务器使用 `cangku-bootstrap` systemd 服务、独立的受限 MySQL 发号账号和 SSH 用户证书 CA。常用命令：
 
 ```bash

remote-access/server/install.sh

@@ -14,7 +14,7 @@ test -f "${MYSQL_ENV}"
 test -f "${SOURCE_DIR}/bootstrap_service.py"
 
 apt-get update -qq
-DEBIAN_FRONTEND=noninteractive apt-get install -y -qq python3-venv openssl certbot >/dev/null
+DEBIAN_FRONTEND=noninteractive apt-get install -y -qq python3-venv openssl certbot python3-certbot-dns-cloudflare >/dev/null
 
 if ! getent passwd cangku-bootstrap >/dev/null; then
   useradd --system --home-dir /var/lib/cangku-bootstrap --create-home --shell /usr/sbin/nologin cangku-bootstrap

remote-access/server/provision-certificate.sh

@@ -7,51 +7,20 @@ if [[ ${EUID} -ne 0 ]]; then
 fi
 
 DOMAIN=ck.yydd.ai
-WEBROOT=/var/www/cangku-bootstrap-acme
-TEMP_SITE=/etc/nginx/sites-available/cangku-bootstrap-acme
 TLS_ROOT=/etc/cangku-tls
-EAB_FILE=${TLS_ROOT}/eab.json
-ACME_SERVER=https://acme.zerossl.com/v2/DV90
+CF_CREDENTIALS=${TLS_ROOT}/cloudflare.ini
 
-DEBIAN_FRONTEND=noninteractive apt-get install -y -qq certbot >/dev/null
-install -d -m 0755 "${WEBROOT}/.well-known/acme-challenge"
+DEBIAN_FRONTEND=noninteractive apt-get install -y -qq certbot python3-certbot-dns-cloudflare >/dev/null
 install -d -m 0700 "${TLS_ROOT}"
 
 if [[ ! -f "/etc/letsencrypt/live/${DOMAIN}/fullchain.pem" ]]; then
-  if [[ ! -f "${EAB_FILE}" ]]; then
-    echo "Missing ${EAB_FILE}; create ZeroSSL EAB credentials and store them there with mode 0600" >&2
+  if [[ ! -f "${CF_CREDENTIALS}" ]]; then
+    echo "Missing ${CF_CREDENTIALS}; store a scoped Cloudflare API token there with mode 0600" >&2
     exit 1
   fi
-  umask 0022
-  {
-    printf 'server {\n'
-    printf '    listen 80;\n'
-    printf '    listen [::]:80;\n'
-    printf '    server_name %s;\n' "${DOMAIN}"
-    printf '    location /.well-known/acme-challenge/ { root %s; }\n' "${WEBROOT}"
-    printf '    location / { return 404; }\n'
-    printf '}\n'
-  } > "${TEMP_SITE}"
-  ln -sfn "${TEMP_SITE}" /etc/nginx/sites-enabled/cangku-bootstrap-acme
-  nginx -t
-  systemctl reload nginx
-  readarray -t eab < <(python3 - "${EAB_FILE}" <<'PY'
-import json
-import sys
-
-with open(sys.argv[1], encoding='utf-8') as handle:
-    value = json.load(handle)
-print(value['eab_kid'])
-print(value['eab_hmac_key'])
-PY
-  )
-  certbot certonly --server "${ACME_SERVER}" \
-    --eab-kid "${eab[0]}" --eab-hmac-key "${eab[1]}" \
-    --webroot -w "${WEBROOT}" -d "${DOMAIN}" \
-    --email certs@yydd.ai --agree-tos --non-interactive --no-eff-email
-  unlink "${EAB_FILE}"
-  unlink /etc/nginx/sites-enabled/cangku-bootstrap-acme
-  unlink "${TEMP_SITE}"
+  chmod 0600 "${CF_CREDENTIALS}"
+  certbot certonly --dns-cloudflare --dns-cloudflare-credentials "${CF_CREDENTIALS}" \
+    -d "${DOMAIN}" --email certs@yydd.ai --agree-tos --non-interactive --no-eff-email
 fi
 
 systemctl enable --now certbot.timer