Linux 下 OpenVPN 安装和 Windows OpenVPN GUI 安装笔记

　　基于伟大的 GFW 越来越牛Ｂ，网站的正常维护如 FTP、pop & smtp 的邮件收发、在 google 查技术资料，都经常被 GFW 强行断开。为了解决这个问题，于是我在自己的国外主机上安装了一个 OpenVPN，当时记录了一下安装的经过。

　　今天正好又有一个朋友问及 OpenVPN 安装的事情，于是我重新整理一下这篇Linux 下 OpenVPN 安装和 Windows OpenVPN GUI 安装笔记(http://www.xiaohui.com/dev/server/20070514-install-openvpn.htm), 希望对大家有所帮助。

　　当时在安装 OpenVPN 的时候，得到了 WenZK 的指导帮助。在此表示感谢。

一. OpenVPN 安装环境

Server 端的环境
1. redhat, kernel版本: 2.4.20-31.9, IP 为 70.8.7.6
2. kernel 需要支持 tun 设备, 需要加载 iptables 模块.
   检查 tun 是否安装:
   代码:

   root@a [/]# modinfo tun 
   filename:    /lib/modules/2.4.20-31.9/kernel/drivers/net/tun.o 
   description:  
   author:       
   license:     "GPL" 
   

   如果没有 modinfo 命令, 直接找一下, 看看 kernel 里是否有 tun.o 文件:
   代码:

   find -name tun.o 
   ./lib/modules/2.4.20/kernel/drivers/net/tun.o 
   

   检查iptables 模块, 查看是否有下列文件:
   /etc/init.d/iptables
3. 安装的 OpenVPN 的版本: 2.0.5. 现在似乎已经有一个更新的版本了. 可在http://openvpn.net 上下载.

Client 端的环境:
1. Windows XP PRO SP2
2. OpenVPN GUI For windows 1.0.3 , 可在 openvpn.se 下载
   注意: OpenVPN GUI for windows 的版本要和 OpenVPN Server 的版本配套.
   例如, 服务器装的是 OpenVPN 2.0.5, 那么下载的 OpenVPN GUI fow windows 应该是: openvpn-2.0.5-gui-1.0.3-install.exe
   OpenVPN GUI的所有历史版本: http://openvpn.se/files/install_packages/

二. OpenVPN 服务端安装过程

1. 用 SecureCRT 登录到 host, 进入根目录 代码:

   cd / 

2. 下载 LZO，解压到lzo-2.02.

   地址: http://www.oberhumer.com/opensource/lzo/download/ 代码:

   wget http://www.oberhumer.com/opensource/lzo/download/lzo-2.02.tar.gz

3. 下载 OpenVPN, 解压到openvpn-2.0.5

   地址: http://openvpn.net/download.html 代码:

   wget http://openvpn.net/release/openvpn-2.0.5.tar.gz

4. 安装 LZO 代码:

   cd /lzo-2.02 
   ./configure 
   make 
   make check 
   make install 

5. 安装 OpenVPN

   代码:

   cd /openvpn-2.0.5
   ./configure 
   # 或用指定dir: (注:下述命令, 应该在一行写完. 为了方便显示, 这里分成了四行)
   # ./configure --with-lzo-headers=/usr/local/include 
   #  --with-lzo-lib=/usr/local/lib 
   #  --with-ssl-headers=/usr/local/include/openssl 
   #  --with-ssl-lib=/usr/local/lib 
   make 
   make install 
   

6. 生成证书Key

   初始化 PKI

   (如果没有 export 命令也可以用 setenv [name] [value] 命令)

   代码:

   cd /openvpn-2.0.5/easy-rsa 
   export D=`pwd` 
   export KEY_CONFIG=$D/openssl.cnf 
   export KEY_DIR=$D/keys 
   export KEY_SIZE=1024 
   export KEY_COUNTRY=CN 
   export KEY_PROVINCE=GD 
   export KEY_CITY=SZ 
   export KEY_ORG="dvdmaster" 
   export KEY_EMAIL="support@cooldvd.com" 

   Build:

   代码:

   ./clean-all 
   ./build-ca 
   
   Generating a 1024 bit RSA private key 
   ................++++++ 
   ........++++++ 
   writing new private key to 'ca.key' 
   ----- 
   You are about to be asked to enter information that will be incorporated 
   into your certificate request. 
   What you are about to enter is what is called a Distinguished Name or a DN. 
   There are quite a few fields but you can leave some blank 
   For some fields there will be a default value, 
   If you enter '.', the field will be left blank. 
   ----- 
   Country Name (2 letter code) [CN]: 
   State or Province Name (full name) [GD]: 
   Locality Name (eg, city) [SZ]: 
   Organization Name (eg, company) [dvdmaster]: 
   Organizational Unit Name (eg, section) []:dvdmaster 
   Common Name (eg, your name or your server's hostname) []:server 
   Email Address [support@cooldvd.com]: 

   # 建立 server key 代码: 代码:

   ./build-key-server server 
   
   Generating a 1024 bit RSA private key 
   ......++++++ 
   ....................++++++ 
   writing new private key to 'server.key' 
   ----- 
   You are about to be asked to enter information that will be incorporated 
   into your certificate request. 
   What you are about to enter is what is called a Distinguished Name or a DN. 
   There are quite a few fields but you can leave some blank 
   For some fields there will be a default value, 
   If you enter '.', the field will be left blank. 
   ----- 
   Country Name (2 letter code) [CN]: 
   State or Province Name (full name) [GD]: 
   Locality Name (eg, city) [SZ]: 
   Organization Name (eg, company) [dvdmaster]: 
   Organizational Unit Name (eg, section) []:dvdmaster 
   Common Name (eg, your name or your server's hostname) []:server 
   Email Address [support@cooldvd.com]: 
   
   Please enter the following 'extra' attributes 
   to be sent with your certificate request 
   A challenge password []:abcd1234 
   An optional company name []:dvdmaster 
   Using configuration from /openvpn-2.0.5/easy-rsa/openssl.cnf 
   Check that the request matches the signature 
   Signature ok 
   The Subject's Distinguished Name is as follows 
   countryName           :PRINTABLE:'CN' 
   stateOrProvinceName   :PRINTABLE:'GD' 
   localityName          :PRINTABLE:'SZ' 
   organizationName      :PRINTABLE:'dvdmaster' 
   organizationalUnitName:PRINTABLE:'dvdmaster' 
   commonName            :PRINTABLE:'server' 
   emailAddress          :IA5STRING:'support@cooldvd.com' 
   Certificate is to be certified until Mar 19 08:15:31 2016 GMT (3650 days) 
   Sign the certificate? [y/n]:y 
   
   
   1 out of 1 certificate requests certified, commit? [y/n]y 
   Write out database with 1 new entries 
   Data Base Updated 

   #生成客户端 key

   代码:

   ./build-key client1 
   Generating a 1024 bit RSA private key 
   .....++++++ 
   ......++++++ 
   writing new private key to 'client1.key' 
   ----- 
   You are about to be asked to enter information that will be incorporated 
   into your certificate request. 
   What you are about to enter is what is called a Distinguished Name or a DN. 
   There are quite a few fields but you can leave some blank 
   For some fields there will be a default value, 
   If you enter '.', the field will be left blank. 
   ----- 
   Country Name (2 letter code) [CN]: 
   State or Province Name (full name) [GD]: 
   Locality Name (eg, city) [SZ]: 
   Organization Name (eg, company) [dvdmaster]: 
   Organizational Unit Name (eg, section) []:dvdmaster 
   Common Name (eg, your name or your server's hostname) []:client1    #重要: 每个不同的 client 生成的证书, 名字必须不同. 
   Email Address [support@cooldvd.com]: 
   
   Please enter the following 'extra' attributes 
   to be sent with your certificate request 
   A challenge password []:abcd1234 
   An optional company name []:dvdmaster 
   Using configuration from /openvpn-2.0.5/easy-rsa/openssl.cnf 
   Check that the request matches the signature 
   Signature ok 
   The Subject's Distinguished Name is as follows 
   countryName           :PRINTABLE:'CN' 
   stateOrProvinceName   :PRINTABLE:'GD' 
   localityName          :PRINTABLE:'SZ' 
   organizationName      :PRINTABLE:'dvdmaster' 
   organizationalUnitName:PRINTABLE:'dvdmaster' 
   commonName            :PRINTABLE:'client1' 
   emailAddress          :IA5STRING:'support@cooldvd.com' 
   Certificate is to be certified until Mar 19 08:22:00 2016 GMT (3650 days) 
   Sign the certificate? [y/n]:y 
   
   
   1 out of 1 certificate requests certified, commit? [y/n]y 
   Write out database with 1 new entries 
   Data Base Updated 

   依次类推生成其他客户端证书/key

   代码:

   ./build-key client2 
   ./build-key client3 

   注意在进入 Common Name (eg, your name or your server's hostname) []: 的输入时, 每个证书输入的名字必须不同.
7. build: 代码:

   
   ./build-dh 

8. 将 keys 下的所有文件打包下载到本地

   代码:

   tar -cf mykeys.tar /openvpn-2.0.5/easy-rsa/keys 
   cp mykeys.tar /home/dvdmastersys/public_html/mykeys.tar 

   将 mykeys.tar 移到 web public(绝对路径因人而异) 上, 然后用 http://www.a.com/mykeys.tar 方式将其下载到本地保存, 然后将其从server删除: 代码:

   rm /home/dvdmastersys/public_html/mykeys.tar 

   也可以用其他方法把 key file搞到本地，例如 ftp.
9. 创建服务端配置文件

   从样例文件创建:

   代码:

   cd $dir/sample-config-files/ # 进入源代码解压目录下的sample-config-files子目录 
   cp server.conf /usr/local/etc  # cp服务器配置文件到/usr/local/etc 
   vi /usr/local/etc/server.conf 

   我建立的server.conf 的内容稍后另附.
10. 创建客户端配置文件

    代码:

    cd $dir/sample-config-files/  #进入源代码解压目录下的sample-config-files子目录 
    cp client.conf /usr/local/etc  #cp客户端配置文件到/usr/local/etc 
    vi /usr/local/etc/client.conf 

    我建立的client.conf 的内容稍后另附.
11. 启动Openvpn: openvpn [server config file] 代码:

    /usr/local/sbin/openvpn --config /usr/local/etc/server.conf 

三. OpenVPN GUI For Windows 客户端安装过程

1. 安装 OpenVPN GUI For Windows, 到 http://openvpn.se 下载. 目前的版本是 1.0.3. 注意: OpenVPN GUI 的版本要和 OpenVPN Server 的版本配套. 详见第一节一. 安装环境中的说明.
2. 依屏幕指示安装openvpn gui.
3. 配置 openvpn gui

   安装结束后, 进入安装文件夹下的 config 目录, 然后将上面第 10 步建立的 client.conf 文件从 server 上下载到此文件夹, 并更名为 client.ovpn

   同时, 将第8 步打包的 mykeys.tar 中的下列证书文件解压到此文件夹:

   代码:

   ca.crt 
   ca.key 
   client1.crt 
   client1.csr 
   client1.key 

   然后双击 client.ovpn 即可启动 openvpn, 或者通过 OpenVPN GUI 的控制启动 VPN.

   如果双击 client.ovpn 没有反应, 则在任务栏点 OpenVPN GUI 的小图标右键, 选择 edit config, 将内容复制过去再保存. 然后再点右键中的 connect即可.

   如果需要第二台机器上使用 vpn , 进行同样的配置, 只需要将 client1.crt, client1.csr, client1.key 换成对应的 client2.xxx 即可, 然后将 client.ovpn 中的对应key文件值改掉.

四. OpenVPN 配置样例文件

1. OpenVPN 服务端：server.conf

   代码:

   local 70.8.7.6 
   port 1194 
   proto udp 
   
   dev tun 
   
   ca /openvpn-2.0.5/easy-rsa/keys/ca.crt 
   cert /openvpn-2.0.5/easy-rsa/keys/server.crt 
   key /openvpn-2.0.5/easy-rsa/keys/server.key  # This file should be kept secret 
   dh /openvpn-2.0.5/easy-rsa/keys/dh1024.pem 
   
   server 10.8.0.0 255.255.255.0 
   
   client-to-client 
   keepalive 10 120 
   
   comp-lzo 
   
   persist-key 
   persist-tun 
   status /openvpn-2.0.5/easy-rsa/keys/openvpn-status.log 
   verb 4 
   
   push "dhcp-option DNS 10.8.0.1" 
   push "dhcp-option DNS 70.88.98.10"  # name server 地址, 如何获取见随后说明 
   push "dhcp-option DNS 70.88.99.11"  # name server 地址, 如何获取见随后说明 

   说明: 有些 domain 被 GFW 封掉了, 这时, 如果要访问这些网站, 应该将 server 上的 DNS push 到 client. 上面示例中的 dns ip: 70.88.98.10, 70.88.99.10, 可以在 /etc/resolv.conf 中找到: 代码:

   vi /etc/resolv.conf 
   nameserver   70.88.98.10 
   nameserver   70.88.99.11 

2. OpenVPN 客户端: client.ovpn

   代码:

   client 
   
   dev tun 
   proto udp 
   
   remote 70.8.7.6 1194 
   
   persist-key 
   persist-tun 
   ca ca.crt 
   cert client1.crt 
   key client1.key 
   ns-cert-type server 
   comp-lzo 
   verb 3 
   
   redirect-gateway def1 

五. OpenVPN 访问外网的设置

1. 打开路由 VPN连接成功后, 还需要设置路由, 才能透过VPN访问Internet. 在 linux host 上添加路由: 代码:

   iptables -t nat -A POSTROUTING -s 10.8.0.0/24 -o eth0 -j SNAT --to-source 70.8.7.6 
   /etc/init.d/iptables save 
   /etc/init.d/iptables restart 

   不同的机器，-o eth0 参数可能不一样，具体可输入 ifconfig 查看，搞清 ip(70.8.7.6)所在的网卡号.

   同时, 需要将 ip forward 打开. 不要用 echo 1 > /proc/sys/net/ipv4/ip_forward 的方式, 这种方式重启后无效. 先查看一下:

   代码:

   
   sysctl -a | grep for 
   #查看结果: 
   net.ipv4.conf.tun0.mc_forwarding = 0 
   net.ipv4.conf.tun0.forwarding = 1 
   net.ipv4.conf.eth0.mc_forwarding = 0 
   net.ipv4.conf.eth0.forwarding = 1 
   net.ipv4.conf.lo.mc_forwarding = 0 
   net.ipv4.conf.lo.forwarding = 1 
   net.ipv4.conf.default.mc_forwarding = 0 
   net.ipv4.conf.default.forwarding = 1 
   net.ipv4.conf.all.mc_forwarding = 0 
   net.ipv4.conf.all.forwarding = 1 
   net.ipv4.ip_forward = 1 

   如果你的主机上列数值不是为1, 则要将其改成1, 例如:

   代码:

   sysctl -w net.ipv4.ip_forward=1 

   依此类推.
2. 开启域名服务器

   如果你需要访问一些已经被GFW封掉了域名的网站, 但你的 OpenVPN 服务器没有被封的话，那么你需要在你的主机上开启 name server, 并将 dns push 给 client。 一般的独立主机, 都带有 private dns server.

   代码:

   rpm -qa | grep bind 
   /etc/init.d/named start 

   另外, 必须保证 server.conf 配置中, 有这三个配置:

   代码:

   push "dhcp-option DNS 10.8.0.1" 
   push "dhcp-option DNS 70.88.98.10"  # name server 地址 
   push "dhcp-option DNS 70.88.99.11"  # name server 地址 

   当 client 连接成功后, 在 cmd 下执行 ipconfig /all, 应该有这类似这样的输出:

   代码:

   Ethernet adapter Local Area Connection 3: 
           Connection-specific DNS Suffix  . : 
           Description . . . . . . . . . . . : TAP-Win32 Adapter V8 
           Physical Address. . . . . . . . . : 00-FF-AA-B0-60-2B 
           Dhcp Enabled. . . . . . . . . . . : Yes 
           Autoconfiguration Enabled . . . . : Yes 
           IP Address. . . . . . . . . . . . : 10.8.0.6 
           Subnet Mask . . . . . . . . . . . : 255.255.255.252 
           Default Gateway . . . . . . . . . : 10.8.0.5 
           DHCP Server . . . . . . . . . . . : 10.8.0.5 
           DNS Servers . . . . . . . . . . . : 10.8.0.1 
                                               70.88.98.10 
                                               70.88.99.11 
           Lease Obtained. . . . . . . . . . : 2006年5月25日 5:13:52 
           Lease Expires . . . . . . . . . . : 2007年5月25日 5:13:52 

六. 设置 OpenVPN 服务器 reboot后自动启动 openvpn

代码:

vi /etc/rc.local 

代码:

/usr/local/sbin/openvpn --config /usr/local/etc/server.conf > /dev/null 2>&1 & 

七. OpenVPN 测试

八. 使用 OpenVPN 的强烈注意事项

相关文章：

如何在 Linux OpenVPN 服务端吊销(revoke) 客户端证书?

Tags: VPN | Linux | OpenVPN | DNS