How do you create a simple SSH port forward in Golang?

Simple SSH Port Forward in Golang

In this article, we will explore how to create a simple SSH port forward, allowing you to connect to a remote port from your local machine.

Creating a Port Forward

To create a port forward, you need to establish an SSH connection and listen on the local port. Once a connection is made, you can forward data between the local and remote ports.

Here's a step-by-step guide:

1. Set up SSH configuration: Create a ssh.ClientConfig object with the necessary authentication information (username, password, server address).
2. Listen on the local port: Create a net.Listener object to listen for incoming connections on the desired local port.
3. Accept incoming connections: Use the listener.Accept() method to accept incoming local connections.
4. Connect to the remote server: Use the provided ssh.ClientConfig object to establish an SSH connection to the remote server.
5. Connect to the remote port: Establish a connection to the specified remote port on the server.
6. Forward data: Use io.Copy() to continuously forward data from the local connection to the remote connection and vice versa.

Example Code

The following Go code demonstrates these steps:

<code class="go">package main

import (
    "io"
    "log"
    "net"
    "golang.org/x/crypto/ssh"
)

func forward(localConn net.Conn, config *ssh.ClientConfig, remoteAddr string) {
    sshClientConn, err := ssh.Dial("tcp", "remote.example.com:22", config)
    if err != nil {
        log.Fatalf("ssh.Dial failed: %s", err)
    }

    sshConn, err := sshClientConn.Dial("tcp", remoteAddr)
    if err != nil {
        log.Fatalf("sshClientConn.Dial failed: %s", err)
    }

    go io.Copy(sshConn, localConn)
    go io.Copy(localConn, sshConn)
}

func main() {
    config := &ssh.ClientConfig{
        User: "username",
        Auth: []ssh.AuthMethod{
            ssh.Password("password"),
        },
    }

    listener, err := net.Listen("tcp", "local.example.com:9000")
    if err != nil {
        log.Fatalf("net.Listen failed: %s", err)
    }

    for {
        localConn, err := listener.Accept()
        if err != nil {
            log.Fatalf("listener.Accept failed: %s", err)
        }

        go forward(localConn, config, "remote.example.com:9999")
    }
}</code>

By following these steps and using the provided code, you can create a simple yet effective SSH port forward and access remote services from your local machine with ease.

The above is the detailed content of How do you create a simple SSH port forward in Golang?. For more information, please follow other related articles on the PHP Chinese website!