centos7上搭建openv**centos7 上搭建openv**

yum install openvpn easy-rsa

echo "net.ipv4.ip_forward = 1" >> /etc/sysctl.conf
sysctl -p

cp /usr/share/doc/easy-rsa-3.0.3/vars.example /etc/openvpn/easy-rsa/vars
cp /usr/share/doc/openvpn-2.4.5/sample/sample-config-files/server.conf /etc/openvpn/

cd /etc/openvpn/easy-rsa/
./easyrsa init-pki

./easyrsa build-ca
Enter PEM pass phrase:
 输入2次pem密码，并记住（输入的pem密码是openvpn，第4步有用）；
........

回车后显示：

CA creation complete and you may now import and sign cert requests.
Your new CA certificate file for publishing is at:
/etc/openvpn/easy-rsa/pki/ca.crt

./easyrsa gen-req server nopass
Common Name (eg: your user, host, or server name) [server]: （server）

Keypair and certificate request completed. Your files are:
req: /etc/openvpn/easy-rsa/pki/reqs/server.req
key: /etc/openvpn/easy-rsa/pki/private/server.key

./easyrsa sign server server
回车后，Confirm request details: （输入yes）
Enter pass phrase for /etc/openvpn/easy-rsa/pki/private/ca.key: 输入第2步的密码

Check that the request matches the signature
Signature ok
The Subject’s Distinguished Name is as follows
commonName :ASN.1 12:‘server’
Certificate is to be certified until Apr 4 06:24:29 2038 GMT (3650 days)


Write out database with 1 new entries
Data Base Updated

Certificate created at: /etc/openvpn/easy-rsa/pki/issued/server.crt

./easyrsa gen-dh

DH parameters of size 2048 created at /etc/openvpn/easy-rsa/pki/dh.pem

cp dh.pem dh2048.pem

openvpn --genkey --secret /etc/openvpn/easy-rsa/ta.key

mkdir /root/client
cd /root/client
cp -r /usr/share/easy-rsa/3.0.3/* ./
./easyrsa init-pki
./easyrsa gen-req client
Common Name (eg: your user, host, or server name) [client]: client（后面需要）

Keypair and certificate request completed. Your files are:
req: /root/client/pki/reqs/client.req
key: /root/client/pki/private/client.key

./easyrsa import-req /root/client/pki/reqs/client.req client

Note: using Easy-RSA configuration from: ./vars

The request has been successfully imported with a short name of: clientone
You may now use this name to perform signing operations on this request.

./easyrsa sign client client

Check that the request matches the signature
Signature ok
The Subject’s Distinguished Name is as follows
commonName :ASN.1 12:‘client’
Certificate is to be certified until Apr 4 16:38:37 2028 GMT (3650 days)

Write out database with 1 new entries
Data Base Updated

Certificate created at: /etc/openvpn/easy-rsa/pki/issued/client.crt

cp pki/ca.crt /etc/openvpn/
cp pki/private/server.key /etc/openvpn/
cp pki/issued/server.crt /etc/openvpn/
cp pki/dh.pem /etc/openvpn/
cp /etc/openvpn/easy-rsa/ta.key /etc/openvpn/

cp pki/ca.crt /root/client/
cp pki/issued/client.crt /root/client/
cp /root/client/pki/private/client.key /root/client/
cp /etc/openvpn/easy-rsa/ta.key  /root/client/

egrep  -v "^$|^#|^;" /etc/openvpn/server.conf

port 1194
proto udp
dev tun
ca /etc/openvpn/ca.crt
cert /etc/openvpn/server.crt
key /etc/openvpn/server.key  # This file should be kept secret
dh /etc/openvpn/dh.pem
server 10.8.0.0 255.255.255.0
ifconfig-pool-persist ipp.txt
push "redirect-gateway def1 bypass-dhcp"
push "dhcp-option DNS 8.8.8.8"
push "dhcp-option DNS 208.67.220.220"
keepalive 10 120
tls-auth ta.key 0 # This file is secret
cipher AES-256-CBC
comp-lzo
max-clients 100
persist-key
persist-tun
status openvpn-status.log
verb 3
explicit-exit-notify 1

systemctl enable openvpn@server.service

systemctl start openvpn@server

systemctl status openvpn@server