OpenVPN 基础配置笔记

Introduction

OpenVPN is a virtual private network (VPN) system that implements techniques to create secure point-to-point or site-to-site connections in routed or bridged configurations and remote access facilities. It implements both client and server applications.

Usage

1. Server End

1.1. Windows

1. Download OpenVPN GUI corresponding your operate system and CPU architecture.
   [Image omitted: OpenVPN GUI download page screenshot]
2. Install OpenVPN GUI
   1. Click Customized Install
[Image omitted: customized install option screenshot]
   2. Make sure every components is entirely installed
      [Image omitted: OpenVPN component selection screenshot 1]
[Image omitted: OpenVPN component selection screenshot 2]
3. Config OpenVPN server
   1. Open folder: C:\Program Files\OpenVPN\easy-rsa and copy vars.example to vars
   2. Open folder C:\Program Files\OpenVPN\easy-rsa through Powershell with system authority.

   PS C:\WINDOWS\system32> cd ‘C:\Program Files\OpenVPN\easy-rsa’
   ```
   3. Start easy-rsa: EasyRSA-Start.bat
[Image omitted: EasyRSA start window screenshot]
   4. Init PKI directory: ./easyrsa init-pki

   	PS C:\Program Files\OpenVPN\easy-rsa> .\EasyRSA-Start.bat
   	Easy-RSA starting..
   	
   	Welcome to the EasyRSA 3 Shell for Windows.
   	Easy-RSA 3 is available under a GNU GPLv2 license.
   	
   	Invoke 'easyrsa' to call the program. Without commands, help is displayed.
   	
   	Using directory: C:/Program Files/OpenVPN/easy-rsa
   	
   	
   	EasyRSA Shell
   	# ./easyrsa init-pki
   	Using Easy-RSA 'vars' configuration:
   	* C:/Program Files/OpenVPN/easy-rsa/vars
   	
   	Notice
   	------
   	'init-pki' complete; you may now create a CA or requests.
   	
   	Your newly created PKI dir is:
   	* C:/Program Files/OpenVPN/easy-rsa/pki
   	
   	Using Easy-RSA configuration:
   	* C:/Program Files/OpenVPN/easy-rsa/vars

	5. Create CA certificate file: `./easyrsa build-ca nopass`
	   ```powershell
		EasyRSA Shell
		# ./easyrsa build-ca nopass
		Using Easy-RSA 'vars' configuration:
		* C:/Program Files/OpenVPN/easy-rsa/vars
		* 
		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.
		-----
		Common Name (eg: your user, host, or server name) [Easy-RSA CA]:vmware
		
		Notice
		------
		CA creation complete. Your new CA certificate is at:
		* C:/Program Files/OpenVPN/easy-rsa/pki/ca.crt
		
		Create an OpenVPN TLS-AUTH|TLS-CRYPT-V1 key now: See 'help gen-tls'
		
		Build-ca completed successfully.

6. Create server certificate and private key: `./easyrsa build-server-full SERVER nopass`
   ```powershell
	EasyRSA Shell
	# ./easyrsa build-server-full vmware nopass
	Using Easy-RSA 'vars' configuration:
	* C:/Program Files/OpenVPN/easy-rsa/vars
	
	Notice
	------
	Private-Key and Public-Certificate-Request files created.
	Your files are:
	* req: C:/Program Files/OpenVPN/easy-rsa/pki/reqs/vmware.req
	* key: C:/Program Files/OpenVPN/easy-rsa/pki/private/vmware.key
	
	You are about to sign the following certificate:
	
	  Requested CN:     'vmware'
	  Requested type:   'server'
	  Valid for:        '825' days
	
	
	subject=
	    commonName                = vmware
	
	Type the word 'yes' to continue, or any other input to abort.
	  Confirm requested details: yes
	
	Using configuration from C:/Program Files/OpenVPN/easy-rsa/pki/c70d8473/temp.6.1
	Check that the request matches the signature
	Signature ok
	The Subject's Distinguished Name is as follows
	commonName            :ASN.1 12:'vmware'
	Certificate is to be certified until Jul  1 06:19:35 2027 GMT (825 days)
	
	Write out database with 1 new entries
	Database updated
	which: no bc in (C:/Program Files/OpenVPN/easy-rsa;C:/Program Files/OpenVPN/easy-rsa/bin;C:\WINDOWS\system32;C:\WINDOWS;C:\WINDOWS\System32\Wbem;C:\WINDOWS\System32\WindowsPowerShell\v1.0\;C:\WINDOWS\System32\OpenSSH\;C:\Users\vmware\AppData\Local\Microsoft\WindowsApps;C:\Program Files\OpenVPN\bin\)
	
	Notice
	------
	Inline file created:
	* C:/Program Files/OpenVPN/easy-rsa/pki/inline/private/vmware.inline
	
	
	Notice
	------
	Certificate created at:
	* C:/Program Files/OpenVPN/easy-rsa/pki/issued/vmware.crt

### 1.2. Linux

https://openvpn.net/as-docs/ubuntu.html
https://www.digitalocean.com/community/tutorials/how-to-set-up-and-configure-an-openvpn-server-on-ubuntu-20-04#step-1-installing-openvpn-and-easy-rsa
## 2. Client End

### 2.1.