fastnat

FAST NAT Full protocol intranet penetration

FAST NAT is an extended version based on WeNAT, supporting HTTP, TCP, UDP, WebSocket and other protocols. Simply put, you can assign a public IP and port to your intranet computer, for example:

123.1.1.1:8888 -> 192.168.1.123:3306

When the data packet is received by the external network server, it will be forwarded to the internal network port 3306, thereby achieving penetration. The server has been transferred, which is different from the traditional P2P penetration.

Application scenarios

• Local publishing website
• remote desktop
• SSH Local Server
• Access local mysql
• Access local redis
• Access local mongodb

Contact information

• QQ group: 524948153
• Email: [email protected]

Development language

• Server side, web website: node.js
• Client: nw.js + node.js

TCP protocol and process

flow chart

Internal and external network proxy process

• Establish protocol channels for the intranet and external networks for active connection notification
• The external network client connects to the server and assigns an id to save it
• Notify the intranet client and tell the id that the intranet will initiate the connection automatically
• Intranet connection proxy target
• Connect to the server in the intranet, and pass in the id to bind to the external network.
• sockets that map internal and external networks

Disconnection and error handling

• Any party reports an error, all ports of the terminal listen and all connections
• The client initiates the connection request again and assigns a random port or continues to use the last external network port.

TCP interface

• Protocol Type

  The protocol is a JSON string

• Security

  When connecting to the server for the first time, you need to bring the user's token. After the server is valid, it will open two ports for subsequent use. In the subsequent process, no verification is done. Although there are security risks, common TCP applications: Mysql, Mongodb, Redis, etc. have user mechanisms to protect.

• Protocol Type

  Three tentative agreements

  type
  TCP
  UDP
  HTTP

• Connect with the communication server

  • Basic information response

    Directly connect to the communication server port 8888 without sending any data. After successful, respond to the following data

    Fields	type	illustrate
    id	string(8)	The id of this session
    outId	string(8)	External socket session id
    intPort	int(5)	Intranet connection port, 5-digit port, 30000-65535
    outPort	int(5)	Ports for external network connections
    Command	string	Operation commands
    protocol	string	Protocol Type

    • Give a chestnut

     {
       id : 'CucfFpk7' ,
       intPort : 61289 ,
       outPort : 59918 ,
       command : 'start_proxy' ,
       outId : 'GpNYO5KW' 
     }

  • Actively connect to the server

    After receiving the basic information response, you get the port of the intranet to establish a TCP connection and bring the outId. The first data packet is a protocol packet, and the subsequent data is normal forwarding.

    Fields	type	illustrate
    outId	string(8)	External socket session id

    • Give a chestnut

     {
       outId : 'GpNYO5KW' 
     }