OpenVPN-一键脚本部署

**相关链接：**
---
OpenVPN_GitHub：https://github.com/Nyr/openvpn-install/
WireGuard_GitHub(大佬其它项目)：https://github.com/Nyr/wireguard-install

## 使用
```bash
# 一键拉取脚本并使用
wget https://git.918178.xyz/https://raw.githubusercontent.com/Nyr/openvpn-install/master/openvpn-install.sh -O openvpn-install.sh && bash openvpn-install.sh
# 也可拉取汉化的脚本
wget http://nas.918178.xyz:3000/WJ/Script/raw/branch/master/openvpn_zwzw.sh && bash openvpn_zwzw.sh

# 生成的客户端配置在 当前用户根目录下，名称为 生成客户端的名称.ovpn
cd /etc/openvpn/server  # server相关配置文件路径
systemctl restart openvpn-server@server.service  # 重启服务(修改服务端配置使用)
```

## 汉化脚本
学习大佬脚本时为了方便阅读加注释和汉化的脚本
```bash
#!/bin/bash
#
# https://githubfast.com/Nyr/openvpn-install
#
# 版权所有 (c) 2013 Nyr.根据 MIT 许可发布.

# 检测是否在 Debian 系统中使用 "sh" 而不是 "bash"
if readlink /proc/$$/exe | grep -q "dash"; then
  echo '此安装程序需要使用 "bash" 而不是 "sh" 运行.'
  exit
fi

# 丢弃 stdin.在包含换行符的单行脚本中运行时需要
read -N 999999 -t 0.001

# 检测是否在 OpenVZ 6 上运行
if [[ $(uname -r | cut -d "." -f 1) -eq 2 ]]; then
  echo "系统运行着一个旧内核，与此安装程序不兼容."
  exit
fi

# 检测操作系统
# $os_version 变量不一定总是在使用，但为了方便起见保留在这里
if grep -qs "ubuntu" /etc/os-release; then
  os="ubuntu"
  os_version=$(grep 'VERSION_ID' /etc/os-release | cut -d '"' -f 2 | tr -d '.')
  group_name="nogroup"
elif [[ -e /etc/debian_version ]]; then
  os="debian"
  os_version=$(grep -oE '[0-9]+' /etc/debian_version | head -1)
  group_name="nogroup"
elif [[ -e /etc/almalinux-release || -e /etc/rocky-release || -e /etc/centos-release ]]; then
  os="centos"
  os_version=$(grep -shoE '[0-9]+' /etc/almalinux-release /etc/rocky-release /etc/centos-release | head -1)
  group_name="nobody"
elif [[ -e /etc/fedora-release ]]; then
  os="fedora"
  os_version=$(grep -oE '[0-9]+' /etc/fedora-release | head -1)
  group_name="nobody"
else
  echo "此安装程序似乎在不受支持的发行版上运行.支持的发行版包括 Ubuntu、Debian、AlmaLinux、Rocky Linux、CentOS 和 Fedora."
  exit
fi

# 确保 Ubuntu 版本不低于 18.04
if [[ "$os" == "ubuntu" && "$os_version" -lt 1804 ]]; then
  echo "需要 Ubuntu 18.04 或更高版本才能使用此安装程序.此版本的 Ubuntu 过于旧且不受支持."
  exit
fi

# 如果是 Debian，确保版本不低于 9
if [[ "$os" == "debian" ]]; then
  if grep -q '/sid' /etc/debian_version; then
    echo "此安装程序不支持 Debian Testing 和 Debian Unstable."
    exit
  fi
  if [[ "$os_version" -lt 9 ]]; then
    echo "需要 Debian 9 或更高版本才能使用此安装程序.此版本的 Debian 过于旧且不受支持."
    exit
  fi
fi

# 如果是 CentOS，确保版本不低于 7
if [[ "$os" == "centos" && "$os_version" -lt 7 ]]; then
  echo "需要 CentOS 7 或更高版本才能使用此安装程序.此版本的 CentOS 过于旧且不受支持."
  exit
fi

# 检测 $PATH 是否包含 sbin 目录
if ! grep -q sbin <<< "$PATH"; then
  echo '$PATH 不包含 sbin.请尝试使用 "su -" 而不是 "su".'
  exit
fi

# 检测是否有 root 权限
if [[ "$EUID" -ne 0 ]]; then
  echo "此安装程序需要以超级用户权限运行."
  exit
fi

# 检测系统是否有 TUN 设备
if [[ ! -e /dev/net/tun ]] || ! ( exec 7<>/dev/net/tun ) 2>/dev/null; then
  echo "系统没有可用的 TUN 设备.在运行此安装程序之前，需要启用 TUN."
  exit
fi

# 生成自定义客户端配置文件
new_client () {
  # 生成自定义 client.ovpn
  {
    cat /etc/openvpn/server/client-common.txt
    echo "<ca>"
    cat /etc/openvpn/server/easy-rsa/pki/ca.crt
    echo "</ca>"
    echo "<cert>"
    sed -ne '/BEGIN CERTIFICATE/,$ p' /etc/openvpn/server/easy-rsa/pki/issued/"$client".crt
    echo "</cert>"
    echo "<key>"
    cat /etc/openvpn/server/easy-rsa/pki/private/"$client".key
    echo "</key>"
    echo "<tls-crypt>"
    sed -ne '/BEGIN OpenVPN Static key/,$ p' /etc/openvpn/server/tc.key
    echo "</tls-crypt>"
  } > ~/"$client".ovpn
}

# 检测是否存在 OpenVPN 服务器配置文件
if [[ ! -e /etc/openvpn/server/server.conf ]]; then
  # 检测某些 Debian 最小安装中未安装 wget 或 curl
  if ! hash wget 2>/dev/null && ! hash curl 2>/dev/null; then
    echo "需要安装 Wget 才能使用此安装程序."
    read -n1 -r -p "按任意键安装 Wget 并继续..."
    apt-get update
    apt-get install -y wget
  fi
  clear
  echo '欢迎使用 OpenVPN road warrior 安装程序!'
  # 如果系统有一个 IPv4 地址，它会自动选择.否则，询问用户
  if [[ $(ip -4 addr | grep inet | grep -vEc '127(\.[0-9]{1,3}){3}') -eq 1 ]]; then
    ip=$(ip -4 addr | grep inet | grep -vE '127(\.[0-9]{1,3}){3}' | cut -d '/' -f 1 | grep -oE '[0-9]{1,3}(\.[0-9]{1,3}){3}')
  else
    number_of_ip=$(ip -4 addr | grep inet | grep -vEc '127(\.[0-9]{1,3}){3}')
    echo
    echo "使用哪个 IPv4 地址?"
    ip -4 addr | grep inet | grep -vE '127(\.[0-9]{1,3}){3}' | cut -d '/' -f 1 | grep -oE '[0-9]{1,3}(\.[0-9]{1,3}){3}' | nl -s ') '
    read -p "IPv4 地址 [1]: " ip_number
    until [[ -z "$ip_number" || "$ip_number" =~ ^[0-9]+$ && "$ip_number" -le "$number_of_ip" ]]; do
    echo "$ip_number: 无效选择."
    read -p "IPv4 地址 [1]: " ip_number
    done
    [[ -z "$ip_number" ]] && ip_number="1"
    ip=$(ip -4 addr | grep inet | grep -vE '127(\.[0-9]{1,3}){3}' | cut -d '/' -f 1 | grep -oE '[0-9]{1,3}(\.[0-9]{1,3}){3}' | sed -n "$ip_number"p)
  fi
  # 如果 $ip 是私有 IP 地址，则服务器必须在 NAT 后面
  if echo "$ip" | grep -qE '^(10\.|172\.1[6789]\.|172\.2[0-9]\.|172\.3[01]\.|192\.168)'; then
    echo
    echo "此服务器在 NAT 后面.公共 IPv4 地址或主机名是什么?"
    # 获取公共 IP 并使用 grep 进行清理
    get_public_ip=$(grep -m 1 -oE '^[0-9]{1,3}(\.[0-9]{1,3}){3}$' <<< "$(wget -T 10 -t 1 -4qO- "http://ip1.dynupdate.no-ip.com/" || curl -m 10 -4Ls "http://ip1.dynupdate.no-ip.com/")")
    read -p "公共 IPv4 地址 / 主机名 [$get_public_ip]: " public_ip
    # 如果 checkip 服务不可用并且用户没有提供输入，请再次询问
    until [[ -n "$get_public_ip" || -n "$public_ip" ]]; do
    echo "无效输入."
    read -p "公共 IPv4 地址 / 主机名: " public_ip
    done
    [[ -z "$public_ip" ]] && public_ip="$get_public_ip"
  fi
  # 如果系统有一个 IPv6 地址，它会自动选择
  if [[ $(ip -6 addr | grep -c 'inet6 [23]') -eq 1 ]]; then
    ip6=$(ip -6 addr | grep 'inet6 [23]' | cut -d '/' -f 1 | grep -oE '([0-9a-fA-F]{0,4}:){1,7}[0-9a-fA-F]{0,4}')
  fi
  # 如果系统有多个 IPv6 地址，询问用户选择一个
  if [[ $(ip -6 addr | grep -c 'inet6 [23]') -gt 1 ]]; then
    number_of_ip6=$(ip -6 addr | grep -c 'inet6 [23]')
    echo
    echo "使用哪个 IPv6 地址?"
    ip -6 addr | grep 'inet6 [23]' | cut -d '/' -f 1 | grep -oE '([0-9a-fA-F]{0,4}:){1,7}[0-9a-fA-F]{0,4}' | nl -s ') '
    read -p "IPv6 地址 [1]: " ip6_number
    until [[ -z "$ip6_number" || "$ip6_number" =~ ^[0-9]+$ && "$ip6_number" -le "$number_of_ip6" ]]; do
    echo "$ip6_number: 无效选择."
    read -p "IPv6 地址 [1]: " ip6_number
    done
    [[ -z "$ip6_number" ]] && ip6_number="1"
    ip6=$(ip -6 addr | grep 'inet6 [23]' | cut -d '/' -f 1 | grep -oE '([0-9a-fA-F]{0,4}:){1,7}[0-9a-fA-F]{0,4}' | sed -n "$ip6_number"p)
  fi
  echo
  echo "OpenVPN 应该使用哪个协议?"
  echo "   1) UDP (推荐)"
  echo "   2) TCP"
  read -p "Protocol [1]: " protocol
  until [[ -z "$protocol" || "$protocol" =~ ^[12]$ ]]; do
    echo "$protocol: invalid selection."
    read -p "Protocol [1]: " protocol
  done
  case "$protocol" in
    1|"") 
    protocol=udp
    ;;
    2) 
    protocol=tcp
    ;;
  esac
  echo
  echo "OpenVPN 应该监听哪个端口?"
  read -p "端口 [1194]: " port
  until [[ -z "$port" || "$port" =~ ^[0-9]+$ && "$port" -le 65535 ]]; do
    echo "$port: invalid port."
    read -p "Port [1194]: " port
  done
  [[ -z "$port" ]] && port="1194"
  echo
  echo "为客户端选择 DNS 服务器："
  echo "   1) 当前系统解析器"
  echo "   2) Google"
  echo "   3) 1.1.1.1"
  echo "   4) OpenDNS"
  echo "   5) Quad9"
  echo "   6) AdGuard"
  read -p "DNS 服务器 [1]: " dns
  until [[ -z "$dns" || "$dns" =~ ^[1-6]$ ]]; do
    echo "$dns: invalid selection."
    read -p "DNS server [1]: " dns
  done
  echo
  # 提示用户输入第一个客户端的名称
  echo "为第一个客户端输入名称："
  read -p "名称 [client]: " unsanitized_client
  # 允许一组有限的字符以避免冲突
  client=$(sed 's/[^0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ_-]/_/g' <<< "$unsanitized_client")
  [[ -z "$client" ]] && client="client"
  echo
  echo "OpenVPN 安装准备开始."
  # 如果 firewalld 或 iptables 尚未安装，则安装防火墙
  if ! systemctl is-active --quiet firewalld.service && ! hash iptables 2>/dev/null; then
    if [[ "$os" == "centos" || "$os" == "fedora" ]]; then
      firewall="firewalld"
      # 我们不想悄悄地启用 firewalld，所以我们发出轻微的警告
      # 如果用户继续，将在安装过程中安装并启用 firewalld
      echo "还需要安装 firewalld 以管理路由表."
    elif [[ "$os" == "debian" || "$os" == "ubuntu" ]]; then
      # iptables 比 firewalld 更不具侵入性，因此没有给出警告
      firewall="iptables"
    fi
  fi
  read -n1 -r -p "按任意键继续..."
  # 如果在容器内运行，则禁用 LimitNPROC 以防止冲突
  if systemd-detect-virt -cq; then
    mkdir /etc/systemd/system/openvpn-server@server.service.d/ 2>/dev/null
    echo "[Service]
    LimitNPROC=infinity" > /etc/systemd/system/openvpn-server@server.service.d/disable-limitnproc.conf
  fi
  # 根据操作系统安装必要的软件包
  if [[ "$os" = "debian" || "$os" = "ubuntu" ]]; then
    apt-get update
    apt-get install -y --no-install-recommends openvpn openssl ca-certificates $firewall
  elif [[ "$os" = "centos" ]]; then
    yum install -y epel-release
    yum install -y openvpn openssl ca-certificates tar $firewall
  else
    # 否则，操作系统必须是 Fedora
    dnf install -y openvpn openssl ca-certificates tar $firewall
  fi
  # 如果刚安装了 firewalld，则启用它
  if [[ "$firewall" == "firewalld" ]]; then
    systemctl enable --now firewalld.service
  fi
  # 获取 easy-rsa
  easy_rsa_url='https://githubfast.com/OpenVPN/easy-rsa/releases/download/v3.1.7/EasyRSA-3.1.7.tgz'
  mkdir -p /etc/openvpn/server/easy-rsa/
  { wget -qO- "$easy_rsa_url" 2>/dev/null || curl -sL "$easy_rsa_url" ; } | tar xz -C /etc/openvpn/server/easy-rsa/ --strip-components 1
  chown -R root:root /etc/openvpn/server/easy-rsa/
  cd /etc/openvpn/server/easy-rsa/
  # 创建 PKI，设置 CA 以及服务器和客户端证书
  ./easyrsa --batch init-pki
  ./easyrsa --batch build-ca nopass
  ./easyrsa --batch --days=3650 build-server-full server nopass
  ./easyrsa --batch --days=3650 build-client-full "$client" nopass
  ./easyrsa --batch --days=3650 gen-crl
  # 移动我们需要的文件
  cp pki/ca.crt pki/private/ca.key pki/issued/server.crt pki/private/server.key pki/crl.pem /etc/openvpn/server
  # 每次客户端连接时都读取 CRL，同时 OpenVPN 被降级为 nobody
  chown nobody:"$group_name" /etc/openvpn/server/crl.pem
  # 在目录中没有 +x，OpenVPN 无法对 CRL 文件运行 stat()
  chmod o+x /etc/openvpn/server/
  # 生成用于 tls-crypt 的密钥
  openvpn --genkey --secret /etc/openvpn/server/tc.key
  # 使用预定义的 ffdhe2048 组创建 DH 参数文件
  echo '-----BEGIN DH PARAMETERS-----
  MIIBCAKCAQEA//////////+t+FRYortKmq/cViAnPTzx2LnFg84tNpWp4TZBFGQz
  +8yTnc4kmz75fS/jY2MMddj2gbICrsRhetPfHtXV/WVhJDP1H18GbtCFY2VVPe0a
  87VXE15/V8k1mE8McODmi3fipona8+/och3xWKE2rec1MKzKT0g6eXq8CrGCsyT7
  YdEIqUuyyOP7uWrat2DX9GgdT0Kj3jlN9K5W7edjcrsZCwenyO4KbXCeAvzhzffi
  7MA0BM0oNC9hkXL+nOmFg/+OTxIy7vKBg8P+OxtMb61zO7X8vC7CIAXFjvGDfRaD
  ssbzSibBsu/6iGtCOGEoXJf//////////wIBAg==
  -----END DH PARAMETERS-----' > /etc/openvpn/server/dh.pem
  # 生成 server.conf
  echo "local $ip
  port $port
  proto $protocol
  dev tun
  ca ca.crt
  cert server.crt
  key server.key
  dh dh.pem
  auth SHA512
  tls-crypt tc.key
  topology subnet
  server 10.8.0.0 255.255.255.0" > /etc/openvpn/server/server.conf
  # IPv6
  if [[ -z "$ip6" ]]; then
    echo 'push "redirect-gateway def1 bypass-dhcp"' >> /etc/openvpn/server/server.conf
  else
    echo 'server-ipv6 fddd:1194:1194:1194::/64' >> /etc/openvpn/server/server.conf
    echo 'push "redirect-gateway def1 ipv6 bypass-dhcp"' >> /etc/openvpn/server/server.conf
  fi
  echo 'ifconfig-pool-persist ipp.txt' >> /etc/openvpn/server/server.conf
  # DNS
  case "$dns" in
    1|"")
      # 查找正确的 resolv.conf
      # 对于运行 systemd-resolved 的系统是必需的
      if grep '^nameserver' "/etc/resolv.conf" | grep -qv '127.0.0.53' ; then
        resolv_conf="/etc/resolv.conf"
      else
        resolv_conf="/run/systemd/resolve/resolv.conf"
      fi
      # 从 resolv.conf 获取解析器并用于 OpenVPN
      grep -v '^#\|^;' "$resolv_conf" | grep '^nameserver' | grep -v '127.0.0.53' | grep -oE '[0-9]{1,3}(\.[0-9]{1,3}){3}' | while read line; do
        echo "push \"dhcp-option DNS $line\"" >> /etc/openvpn/server/server.conf
      done
    ;;
    2)
      echo 'push "dhcp-option DNS 8.8.8.8"' >> /etc/openvpn/server/server.conf
      echo 'push "dhcp-option DNS 8.8.4.4"' >> /etc/openvpn/server/server.conf
    ;;
    3)
      echo 'push "dhcp-option DNS 1.1.1.1"' >> /etc/openvpn/server/server.conf
      echo 'push "dhcp-option DNS 1.0.0.1"' >> /etc/openvpn/server/server.conf
    ;;
    4)
      echo 'push "dhcp-option DNS 208.67.222.222"' >> /etc/openvpn/server/server.conf
      echo 'push "dhcp-option DNS 208.67.220.220"' >> /etc/openvpn/server/server.conf
    ;;
    5)
      echo 'push "dhcp-option DNS 9.9.9.9"' >> /etc/openvpn/server/server.conf
      echo 'push "dhcp-option DNS 149.112.112.112"' >> /etc/openvpn/server/server.conf
    ;;
    6)
      echo 'push "dhcp-option DNS 94.140.14.14"' >> /etc/openvpn/server/server.conf
      echo 'push "dhcp-option DNS 94.140.15.15"' >> /etc/openvpn/server/server.conf
    ;;
  esac
  echo 'push "block-outside-dns"' >> /etc/openvpn/server/server.conf
  # 配置 OpenVPN 服务器的一些参数
  echo "keepalive 10 120
  user nobody
  group $group_name
  persist-key
  persist-tun
  verb 3
  crl-verify crl.pem" >> /etc/openvpn/server/server.conf
  if [[ "$protocol" = "udp" ]]; then
    echo "explicit-exit-notify" >> /etc/openvpn/server/server.conf
  fi
  # 启用系统的 net.ipv4.ip_forward
  echo 'net.ipv4.ip_forward=1' > /etc/sysctl.d/99-openvpn-forward.conf
  # 立即启用，无需等待重启或服务重启
  echo 1 > /proc/sys/net/ipv4/ip_forward
  if [[ -n "$ip6" ]]; then
    # 启用系统的 net.ipv6.conf.all.forwarding
    echo "net.ipv6.conf.all.forwarding=1" >> /etc/sysctl.d/99-openvpn-forward.conf
    # 立即启用，无需等待重启或服务重启
    echo 1 > /proc/sys/net/ipv6/conf/all/forwarding
  fi
  if systemctl is-active --quiet firewalld.service; then
    # 使用永久和非永久规则以避免 firewalld 的重新加载.
    # 我们不使用 --add-service=openvpn，因为它只能与默认端口和协议一起使用.
    firewall-cmd --add-port="$port"/"$protocol"
    firewall-cmd --zone=trusted --add-source=10.8.0.0/24
    firewall-cmd --permanent --add-port="$port"/"$protocol"
    firewall-cmd --permanent --zone=trusted --add-source=10.8.0.0/24
    # 为 VPN 子网设置 NAT
    firewall-cmd --direct --add-rule ipv4 nat POSTROUTING 0 -s 10.8.0.0/24 ! -d 10.8.0.0/24 -j SNAT --to "$ip"
    firewall-cmd --permanent --direct --add-rule ipv4 nat POSTROUTING 0 -s 10.8.0.0/24 ! -d 10.8.0.0/24 -j SNAT --to "$ip"
    if [[ -n "$ip6" ]]; then
      firewall-cmd --zone=trusted --add-source=fddd:1194:1194:1194::/64
      firewall-cmd --permanent --zone=trusted --add-source=fddd:1194:1194:1194::/64
      firewall-cmd --direct --add-rule ipv6 nat POSTROUTING 0 -s fddd:1194:1194:1194::/64 ! -d fddd:1194:1194:1194::/64 -j SNAT --to "$ip6"
      firewall-cmd --permanent --direct --add-rule ipv6 nat POSTROUTING 0 -s fddd:1194:1194:1194::/64 ! -d fddd:1194:1194:1194::/64 -j SNAT --to "$ip6"
    fi
  else
    # 创建设置持久 iptables 规则的服务
    iptables_path=$(command -v iptables)
    ip6tables_path=$(command -v ip6tables)
    # 如果我们在 OVZ 中，具有 nf_tables 后端且 iptables-legacy 可用，则使用 iptables-legacy.
    if [[ $(systemd-detect-virt) == "openvz" ]] && readlink -f "$(command -v iptables)" | grep -q "nft" && hash iptables-legacy 2>/dev/null; then
      iptables_path=$(command -v iptables-legacy)
      ip6tables_path=$(command -v ip6tables-legacy)
    fi
    echo "[Unit]
    Before=network.target
    [Service]
    Type=oneshot
    ExecStart=$iptables_path -t nat -A POSTROUTING -s 10.8.0.0/24 ! -d 10.8.0.0/24 -j SNAT --to $ip
    ExecStart=$iptables_path -I INPUT -p $protocol --dport $port -j ACCEPT
    ExecStart=$iptables_path -I FORWARD -s 10.8.0.0/24 -j ACCEPT
    ExecStart=$iptables_path -I FORWARD -m state --state RELATED,ESTABLISHED -j ACCEPT
    ExecStop=$iptables_path -t nat -D POSTROUTING -s 10.8.0.0/24 ! -d 10.8.0.0/24 -j SNAT --to $ip
    ExecStop=$iptables_path -D INPUT -p $protocol --dport $port -j ACCEPT
    ExecStop=$iptables_path -D FORWARD -s 10.8.0.0/24 -j ACCEPT
    ExecStop=$iptables_path -D FORWARD -m state --state RELATED,ESTABLISHED -j ACCEPT" > /etc/systemd/system/openvpn-iptables.service
    if [[ -n "$ip6" ]]; then
      echo "ExecStart=$ip6tables_path -t nat -A POSTROUTING -s fddd:1194:1194:1194::/64 ! -d fddd:1194:1194:1194::/64 -j SNAT --to $ip6
      ExecStart=$ip6tables_path -I FORWARD -s fddd:1194:1194:1194::/64 -j ACCEPT
      ExecStart=$ip6tables_path -I FORWARD -m state --state RELATED,ESTABLISHED -j ACCEPT
      ExecStop=$ip6tables_path -t nat -D POSTROUTING -s fddd:1194:1194:1194::/64 ! -d fddd:1194:1194:1194::/64 -j SNAT --to $ip6
      ExecStop=$ip6tables_path -D FORWARD -s fddd:1194:1194:1194::/64 -j ACCEPT
      ExecStop=$ip6tables_path -D FORWARD -m state --state RELATED,ESTABLISHED -j ACCEPT" >> /etc/systemd/system/openvpn-iptables.service
    fi
  fi
  # 将配置信息添加到 OpenVPN 服务的 systemd 单元文件中
  echo "RemainAfterExit=yes
  [Install]
  WantedBy=multi-user.target" >> /etc/systemd/system/openvpn-iptables.service

# 启用并立即启动 openvpn-iptables 服务
  systemctl enable --now openvpn-iptables.service

# 如果 SELinux 启用并选择了自定义端口，则需要进行以下设置
  if sestatus 2>/dev/null | grep "Current mode" | grep -q "enforcing" && [[ "$port" != 1194 ]]; then
    # 如果尚未安装 semanage，则安装相应的软件包
    if ! hash semanage 2>/dev/null; then
      if [[ "$os_version" -eq 7 ]]; then
        # CentOS 7
        yum install -y policycoreutils-python
      else
        # CentOS 8 或 Fedora
        dnf install -y policycoreutils-python-utils
      fi
    fi
    # 使用 semanage 设置端口类型和协议
    semanage port -a -t openvpn_port_t -p "$protocol" "$port"
  fi

# 如果服务器位于 NAT 后，请使用正确的 IP 地址
  [[ -n "$public_ip" ]] && ip="$public_ip"

# 创建 client-common.txt 以供后续添加用户时使用
  echo "client
  dev tun
  proto $protocol
  remote $ip $port
  resolv-retry infinite
  nobind
  persist-key
  persist-tun
  remote-cert-tls server
  auth SHA512
  ignore-unknown-option block-outside-dns
  verb 3" > /etc/openvpn/server/client-common.txt

# 启用并立即启动 OpenVPN 服务
  systemctl enable --now openvpn-server@server.service

# 生成自定义的 client.ovpn 文件
  new_client

# 输出信息
  echo
  echo "完成!"
  echo
  echo "客户端配置文件可在以下路径找到:" ~/"$client.ovpn"
  echo "可以通过再次运行脚本来添加新客户端."
else
  # OpenVPN 已经安装，显示选项菜单
  clear
  echo "OpenVPN 已安装."
  echo
  echo "选择一个选项:"
  echo "   1) 添加新客户端"
  echo "   2) 撤销现有客户端"
  echo "   3) 移除 OpenVPN"
  echo "   4) 退出"
  read -p "选项: " option
  until [[ "$option" =~ ^[1-4]$ ]]; do
  echo "$option: 选择无效."
  read -p "选项: " option
  done
  case "$option" in
    1)
      # 添加新客户端
      echo
      echo "为客户端提供一个名称:"
      read -p "名称: " unsanitized_client
      client=$(sed 's/[^0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ_-]/_/g' <<< "$unsanitized_client")
      while [[ -z "$client" || -e /etc/openvpn/server/easy-rsa/pki/issued/"$client".crt ]]; do
        echo "$client: 名称无效."
        read -p "名称: " unsanitized_client
        client=$(sed 's/[^0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ_-]/_/g' <<< "$unsanitized_client")
      done
      # 使用 easyrsa 添加新客户端
      cd /etc/openvpn/server/easy-rsa/
      ./easyrsa --batch --days=3650 build-client-full "$client" nopass
      # 生成客户端的自定义配置文件 client.ovpn
      new_client
      echo
      echo "$client 已添加.配置文件可在以下路径找到:" ~/"$client.ovpn"
      exit
    ;;
    2)
      # 该选项可能需要更好的文档说明，甚至可以简化一些步骤
      # ...但我想说，我也想要一些睡眠时间
      # 统计当前存在的客户端数量
      number_of_clients=$(tail -n +2 /etc/openvpn/server/easy-rsa/pki/index.txt | grep -c "^V")
      if [[ "$number_of_clients" = 0 ]]; then
        echo
        echo "没有现有的客户端!"
        exit
      fi
      echo
      echo "选择要撤销的客户端:"
      # 列出可供选择的客户端
      tail -n +2 /etc/openvpn/server/easy-rsa/pki/index.txt | grep "^V" | cut -d '=' -f 2 | nl -s ') '
      read -p "客户端: " client_number
      # 确保选择的是有效的数字
      until [[ "$client_number" =~ ^[0-9]+$ && "$client_number" -le "$number_of_clients" ]]; do
      echo "$client_number: 选择无效."
      read -p "客户端: " client_number
      done
      # 获取选择的客户端名称
      client=$(tail -n +2 /etc/openvpn/server/easy-rsa/pki/index.txt | grep "^V" | cut -d '=' -f 2 | sed -n "$client_number"p)
      echo
      read -p "确认撤销 $client 吗? [y/N]: " revoke
      # 确保输入是有效的
      until [[ "$revoke" =~ ^[yYnN]*$ ]]; do
      echo "$revoke: 选择无效."
      read -p "确认撤销 $client 吗? [y/N]: " revoke
      done
      if [[ "$revoke" =~ ^[yY]$ ]]; then
        # 撤销客户端证书并生成新的证书吊销列表 (CRL)
        cd /etc/openvpn/server/easy-rsa/
        ./easyrsa --batch revoke "$client"
        ./easyrsa --batch --days=3650 gen-crl
        rm -f /etc/openvpn/server/crl.pem
        cp /etc/openvpn/server/easy-rsa/pki/crl.pem /etc/openvpn/server/crl.pem
        # 每次客户端连接时都读取 CRL，当 OpenVPN 降权为 nobody 时
        chown nobody:"$group_name" /etc/openvpn/server/crl.pem
        echo
        echo "$client 已撤销!"
      else
        echo
        echo "$client 撤销操作已中止!"
      fi
      exit
    ;;
    3)
      echo
      read -p "确认移除 OpenVPN 吗? [y/N]: " remove
      # 确保输入是有效的
      until [[ "$remove" =~ ^[yYnN]*$ ]]; do
      echo "$remove: 选择无效."
      read -p "确认移除 OpenVPN 吗? [y/N]: " remove
      done
      if [[ "$remove" =~ ^[yY]$ ]]; then
        # 获取配置文件中的端口和协议
        port=$(grep '^port ' /etc/openvpn/server/server.conf | cut -d " " -f 2)
        protocol=$(grep '^proto ' /etc/openvpn/server/server.conf | cut -d " " -f 2)
        # 检查是否启用了 firewalld 服务
        if systemctl is-active --quiet firewalld.service; then
          # 获取 NAT 规则中的源 IP 地址
          ip=$(firewall-cmd --direct --get-rules ipv4 nat POSTROUTING | grep '\-s 10.8.0.0/24 '"'"'!'"'"' -d 10.8.0.0/24' | grep -oE '[^ ]+$')
          # 使用永久和非永久规则以避免 firewalld 重新加载
          firewall-cmd --remove-port="$port"/"$protocol"
          firewall-cmd --zone=trusted --remove-source=10.8.0.0/24
          firewall-cmd --permanent --remove-port="$port"/"$protocol"
          firewall-cmd --permanent --zone=trusted --remove-source=10.8.0.0/24
          firewall-cmd --direct --remove-rule ipv4 nat POSTROUTING 0 -s 10.8.0.0/24 ! -d 10.8.0.0/24 -j SNAT --to "$ip"
          firewall-cmd --permanent --direct --remove-rule ipv4 nat POSTROUTING 0 -s 10.8.0.0/24 ! -d 10.8.0.0/24 -j SNAT --to "$ip"
          # 如果配置文件中启用了 IPv6 支持，还需处理 IPv6 地址
          if grep -qs "server-ipv6" /etc/openvpn/server/server.conf; then
            ip6=$(firewall-cmd --direct --get-rules ipv6 nat POSTROUTING | grep '\-s fddd:1194:1194:1194::/64 '"'"'!'"'"' -d fddd:1194:1194:1194::/64' | grep -oE '[^ ]+$')
            firewall-cmd --zone=trusted --remove-source=fddd:1194:1194:1194::/64
            firewall-cmd --permanent --zone=trusted --remove-source=fddd:1194:1194:1194::/64
            firewall-cmd --direct --remove-rule ipv6 nat POSTROUTING 0 -s fddd:1194:1194:1194::/64 ! -d fddd:1194:1194:1194::/64 -j SNAT --to "$ip6"
            firewall-cmd --permanent --direct --remove-rule ipv6 nat POSTROUTING 0 -s fddd:1194:1194:1194::/64 ! -d fddd:1194:1194:1194::/64 -j SNAT --to "$ip6"
          fi
        else
          # 关闭并禁用 openvpn-iptables 服务
          systemctl disable --now openvpn-iptables.service
          rm -f /etc/systemd/system/openvpn-iptables.service
        fi
        # 如果 SELinux 启用且配置了自定义端口，则删除相应的 SELinux 策略
        if sestatus 2>/dev/null | grep "Current mode" | grep -q "enforcing" && [[ "$port" != 1194 ]]; then
          semanage port -d -t openvpn_port_t -p "$protocol" "$port"
        fi
        # 关闭并禁用 OpenVPN 服务
        systemctl disable --now openvpn-server@server.service
        # 删除相关文件和配置
        rm -f /etc/systemd/system/openvpn-server@server.service.d/disable-limitnproc.conf
        rm -f /etc/sysctl.d/99-openvpn-forward.conf
        # 根据操作系统卸载 OpenVPN 软件包
        if [[ "$os" = "debian" || "$os" = "ubuntu" ]]; then
          rm -rf /etc/openvpn/server
          apt-get remove --purge -y openvpn
        else
          # 否则，操作系统必须是 CentOS 或 Fedora
          yum remove -y openvpn
          rm -rf /etc/openvpn/server
        fi
        echo
        echo "OpenVPN 已移除!"
      else
        echo
        echo "OpenVPN 移除操作已中止!"
      fi
      exit
    ;;
    4)
      exit
    ;;
  esac
fi
```