package main
import (
"crypto/rand"
"encoding/hex"
"flag"
"fmt"
"html/template"
"io"
"log"
"mime"
"net/http"
"os"
"path"
"path/filepath"
"strings"
"time"
"github.com/msteinert/pam"
)
type Config struct {
Listen string
StorageDir string
BaseURL string
MaxFileSize int64
ExpireHours int
IndexHTML string
}
type ImagePageData struct {
Title string
ImageURL string
BaseURL string
Description string
FullImageURL string
}
var config Config
var indexHTML string
var imagePageTemplate string
func loadIndexHTML() {
content, err := os.ReadFile(config.IndexHTML)
if err != nil {
panic(err)
}
indexHTML = string(content)
// HTML template for rendering images
imagePageTemplate = `
{{.Title}}
`
}
func init() {
flag.StringVar(&config.Listen, "listen", ":8080", "Address to listen on")
flag.StringVar(&config.StorageDir, "storage", "/tmp/share", "Directory to store uploaded files")
flag.StringVar(&config.BaseURL, "baseurl", "http://localhost:8080", "Base URL for generated file links")
flag.Int64Var(&config.MaxFileSize, "maxsize", 10*1024*1024, "Maximum allowed file size in bytes")
flag.IntVar(&config.ExpireHours, "expire", 24, "Number of hours before files are deleted")
flag.StringVar(&config.IndexHTML, "index", "index.html", "Path to html file to serve as index")
}
func authenticateUser(username, password string) bool {
t, err := pam.StartFunc("system-auth", username, func(s pam.Style, msg string) (string, error) {
switch s {
case pam.PromptEchoOff:
return password, nil
}
return "", fmt.Errorf("unsupported PAM style")
})
if err != nil {
return false
}
err = t.Authenticate(0)
return err == nil
}
func generateRandomFilename() (string, error) {
bytes := make([]byte, 16)
if _, err := rand.Read(bytes); err != nil {
return "", err
}
return hex.EncodeToString(bytes), nil
}
func cleanupOldFiles() {
ticker := time.NewTicker(1 * time.Hour)
for range ticker.C {
now := time.Now()
err := filepath.Walk(config.StorageDir, func(path string, info os.FileInfo, err error) error {
if err != nil {
return err
}
if !info.IsDir() && now.Sub(info.ModTime()) > time.Duration(config.ExpireHours)*time.Hour {
os.Remove(path)
}
return nil
})
if err != nil {
log.Printf("Cleanup error: %v", err)
}
}
}
func isImageFile(filePath string) bool {
file, err := os.Open(filePath)
if err != nil {
log.Printf("Error opening file for MIME detection: %v", err)
return false
}
defer file.Close()
buffer := make([]byte, 512)
_, err = file.Read(buffer)
if err != nil && err != io.EOF {
log.Printf("Error reading file for MIME detection: %v", err)
return false
}
_, err = file.Seek(0, 0)
if err != nil {
log.Printf("Error seeking file after MIME detection: %v", err)
return false
}
contentType := http.DetectContentType(buffer)
log.Printf("Detected content type for %s: %s", filePath, contentType)
return strings.HasPrefix(contentType, "image/")
}
func handleUpload(w http.ResponseWriter, r *http.Request) {
if r.Method != http.MethodPut {
http.Error(w, "Method not allowed", http.StatusMethodNotAllowed)
return
}
username, password, ok := r.BasicAuth()
if !ok || !authenticateUser(username, password) {
w.Header().Set("WWW-Authenticate", `Basic realm="Upload"`)
http.Error(w, "Unauthorized", http.StatusUnauthorized)
return
}
if r.ContentLength > config.MaxFileSize {
http.Error(w, "File too large", http.StatusRequestEntityTooLarge)
return
}
ext := path.Ext(r.URL.Path)
if ext == "" {
contentType := r.Header.Get("Content-Type")
exts, _ := mime.ExtensionsByType(contentType)
if len(exts) > 0 {
ext = exts[0]
}
}
randomName, err := generateRandomFilename()
if err != nil {
http.Error(w, "Internal server error", http.StatusInternalServerError)
return
}
filename := randomName + ext
filepath := path.Join(config.StorageDir, filename)
f, err := os.Create(filepath)
if err != nil {
http.Error(w, "Internal server error", http.StatusInternalServerError)
return
}
defer f.Close()
_, err = io.Copy(f, r.Body)
if err != nil {
os.Remove(filepath)
http.Error(w, "Internal server error", http.StatusInternalServerError)
return
}
fileURL := strings.TrimRight(config.BaseURL, "/") + "/" + filename
fmt.Fprintf(w, "%s\n", fileURL)
}
func handleIndex(w http.ResponseWriter, r *http.Request) {
if r.URL.Path == "/" {
tmpl, err := template.New("index").Parse(indexHTML)
if err != nil {
http.Error(w, "Internal server error", http.StatusInternalServerError)
return
}
tmpl.Execute(w, config)
return
}
requestPath := strings.TrimPrefix(r.URL.Path, "/")
filePath := path.Join(config.StorageDir, requestPath)
log.Printf("Requested path: %s, File path: %s", r.URL.Path, filePath)
fileInfo, err := os.Stat(filePath)
if err != nil {
log.Printf("File not found: %s, Error: %v", filePath, err)
http.NotFound(w, r)
return
}
if r.URL.Query().Get("raw") == "true" || r.URL.Query().Get("download") == "true" {
if r.URL.Query().Get("download") == "true" {
w.Header().Set("Content-Disposition", fmt.Sprintf("attachment; filename=\"%s\"", filepath.Base(requestPath)))
}
log.Printf("Serving file directly: %s", filePath)
http.ServeFile(w, r, filePath)
return
}
if !isImageFile(filePath) {
log.Printf("File is not an image, serving directly: %s", filePath)
http.ServeFile(w, r, filePath)
return
}
tmpl, err := template.New("imagePage").Parse(imagePageTemplate)
if err != nil {
log.Printf("Template parsing error: %v", err)
http.Error(w, "Internal server error", http.StatusInternalServerError)
return
}
baseURL := strings.TrimRight(config.BaseURL, "/")
data := ImagePageData{
Title: "Filename: " + filepath.Base(requestPath),
ImageURL: r.URL.Path, // Use the original request path for the image URL
BaseURL: baseURL,
Description: fmt.Sprintf("Image shared on %s, size: %d bytes", fileInfo.ModTime().Format("Jan 2, 2006"), fileInfo.Size()),
FullImageURL: baseURL + r.URL.Path + "?raw=true", // Full URL for the image with raw parameter
}
log.Printf("Serving image template with data: %+v", data)
w.Header().Set("Content-Type", "text/html; charset=utf-8")
tmpl.Execute(w, data)
}
func main() {
flag.Parse()
loadIndexHTML()
if err := os.MkdirAll(config.StorageDir, 0700); err != nil {
log.Fatalf("Failed to create storage directory: %v", err)
}
go cleanupOldFiles()
http.HandleFunc("/", handleIndex)
http.HandleFunc("/upload", handleUpload)
log.Printf("Starting server on %s", config.Listen)
log.Printf("Storage directory: %s", config.StorageDir)
log.Printf("Base URL: %s", config.BaseURL)
log.Fatal(http.ListenAndServe(config.Listen, nil))
}