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
redhat, kernel版本: 2.4.20-31.9, IP 为 70.8.7.6
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
OpenSSL。如果需要启用 SSL 连接，则需要先安装 OpenSSL。安装 OpenSSL 的方法在这里不做介绍，具体可以用 Google 搜索。CentOS 下可以用 yum install:
yum install openssl
yum install openssl-devel
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:
Windows XP PRO SP2
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
http://www.xiaohui.com/dev/server/20070514-install-openvpn.htm
用 SecureCRT 登录到 host, 进入根目录 代码:
cd /
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
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
安装 LZO 代码:
cd /lzo-2.02
./configure
make
make check
make install
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
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="xiaohui.com"
export KEY_EMAIL="your-email [at] xiaohui.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) [xiaohui.com]:
Organizational Unit Name (eg, section) []:xiaohui.com
Common Name (eg, your name or your server's hostname) []:server
Email Address [your-email [at] xiaohui.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) [xiaohui.com]:
Organizational Unit Name (eg, section) []:xiaohui.com
Common Name (eg, your name or your server's hostname) []:server
Email Address [your-email [at] xiaohui.com]:
Please enter the following 'extra' attributes
to be sent with your certificate request
A challenge password []:abcd1234
An optional company name []:xiaohui.com
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:'xiaohui.com'
organizationalUnitName:PRINTABLE:'xiaohui.com'
commonName :PRINTABLE:'server'
emailAddress :IA5STRING:'your-email [at] xiaohui.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) [xiaohui.com]:
Organizational Unit Name (eg, section) []:xiaohui.com
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 [your-email [at] xiaohui.com]:
Please enter the following 'extra' attributes
to be sent with your certificate request
A challenge password []:abcd1234
An optional company name []:xiaohui.com
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:'xiaohui.com'
organizationalUnitName:PRINTABLE:'xiaohui.com'
commonName :PRINTABLE:'client1'
emailAddress :IA5STRING:'your-email [at] xiaohui.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.
生成 Diffie Hellman 参数 。代码:
./build-dh
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/xiaohui.comsys/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/xiaohui.comsys/public_html/mykeys.tar
也可以用其他方法把 key file搞到本地，例如 ftp.
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.
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.
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
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.
依屏幕指示安装openvpn gui.
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
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
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
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.
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
执行命令:
代码:
vi /etc/rc.local
然后在最后面加入此行:
代码:
/usr/local/sbin/openvpn --config /usr/local/etc/server.conf > /dev/null 2>&1 &
七. OpenVPN 测试
你可以用 VPN 登录上去之后, 测试 MSN, QQ, IE 等网络应用, 也可以尝试访问一些被 GFW 禁掉的网站, 当然, 前提是你的 VPN 服务器不在境内.
八. 使用 OpenVPN 的强烈注意事项
不建议用 VPN 登录 paypal 帐户和 google adsense 帐户. 否则有可能导致帐户受限或带来其他风险.
十. 一些补充
2011.01.11 补充：今天用 yum -y update 升级了 CentOS 之后，发现 OpenVPN 连接不上去了，老是说用户检验出错。经检查 server log，发现有以下日志：
Thu Feb 10 11:13:07 2011 us=3362 222.244.***.**:45771 TLS: Initial packet from 222.244.***.**:45771, sid=eec450eb 8673ceef
Thu Feb 10 11:13:10 2011 us=798063 222.244.***.**:45771 openvpn_execve: external program may not be called unless '--script-secur ity 2' or higher is enabled. Use '--script-security 3 system' for backward compatibility with 2.1_rc8 and earlier. See --help t ext or man page for detailed info.
Thu Feb 10 11:13:10 2011 us=798127 222.244.***.**:45771 TLS Auth Error: user-pass-verify script failed to execute: /usr/bin/php - q /home/xiaohui/openvpn-manager/admin/openvpn-auth.php
Thu Feb 10 11:13:10 2011 us=798141 222.244.***.**:45771 TLS Auth Error: Auth Username/Password verification failed for peer
经查，原来是 CentOS 在进行 yum update 时，将 OpenVPN 也由2.0 升级到了 2.1。而 OpenVPN 2.1 最大的改变之一，就是加了一个 script-security参数。如果按我的这篇教程进行安装，但装的是 OpenVPN 2.1 及以上版本的话，记得在 server.conf 中再加上这么一行配置即可：
script-security 3
=======================================
./configure --with-lzo-headers=/usr/local/include/ --with-lzo-lib=/usr/local/lib --with-ssl-headers=/usr/include/openssl/ --with-ssl-lib=/usr/lib/openssl/
http://www.oberhumer.com/opensource/lzo/download/
http://www.oberhumer.com/opensource/lzo/download/lzo-2.05.tar.gz
http://openvpn.net/index.php/open-source/downloads.html
wget http://swupdate.openvpn.org/community/releases/openvpn-2.2.1.tar.gz