FTPS Server

To create an FTPS server program in Go, you need to create a few files: main.go for the main logic and optionally, a server.go file for the server functionality. Here is a step-by-step guide:

Step 1: Initialize the Go Module

First, create a new directory for your project and initialize the Go module.

mkdir ftpsserver
cd ftpsserver
go mod init github.com/username/ftpsserver

Step 2: Create the `server.go` File

Create a server.go file to handle the FTPS server functionality.

// server.go
package main

import (
    "crypto/tls"
    "log"
    "github.com/goftp/server"
)

// StartServer starts the FTPS server on the specified port.
func StartServer(port string) error {
    factory := &server.SimplePerm{
        User: "test",
        Pass: "1234",
    }

    driver, err := server.NewFileDriver("/tmp")
    if err != nil {
        return err
    }

    tlsConfig := &tls.Config{
        Certificates: []tls.Certificate{loadCertificate()},
    }

    opts := &server.ServerOpts{
        Factory:  factory,
        Port:     port,
        Driver:   driver,
        Auth:     &server.SimpleAuth{Name: "test", Password: "1234"},
        Perm:     factory,
        TLSConfig: tlsConfig,
    }

    ftpsServer := server.NewServer(opts)
    return ftpsServer.ListenAndServe()
}

func loadCertificate() tls.Certificate {
    cert, err := tls.LoadX509KeyPair("server.crt", "server.key")
    if err != nil {
        log.Fatalf("Failed to load certificate: %v", err)
    }
    return cert
}

Step 3: Create the `main.go` File

Create a main.go file to use the server functionality.

// main.go
package main

import (
    "fmt"
    "os"
)

func main() {
    if len(os.Args) != 2 {
        fmt.Println("Usage: ftpsserver <port>")
        os.Exit(1)
    }

    port := os.Args[1]
    fmt.Printf("Starting FTPS server on port %s...\n", port)
    if err := StartServer(port); err != nil {
        fmt.Printf("Server failed: %v\n", err)
        os.Exit(1)
    }
}

Step 4: Generate SSL Certificates

You need SSL certificates to run this server. You can generate self-signed certificates using OpenSSL:

openssl req -x509 -newkey rsa:4096 -keyout key.pem -out cert.pem -days 365 -nodes -subj "/C=SE/ST=Skåne/L=Malmö/O=Example/OU=Development/CN=example.com"

Step 5: Run the Program

Run the program using the go run command.

go run main.go 2121

This will start the FTPS server on port 2121. You can connect to it using an FTPS client with the username test and password 1234.

Last modified: 01 January 2025