initial commit

14 files changed, 436 insertions, 0 deletions

diff --git a/config/config.go b/config/config.go
new file mode 100644
index 0000000..691e756
--- /dev/null
+++ b/config/config.go
@@ -0,0 +1,46 @@
+package config
+
+import (
+	"encoding/json"
+	"io"
+	"os"
+)
+
+type Configuration struct {
+	Http struct {
+		ListenAddress string `json:"listen"`
+		BaseAddress   string `json:"base"`
+	} `json:"http"`
+	Authentication struct {
+		Username string `json:"username"`
+		Password string `json:"password"`
+	} `json:"auth"`
+}
+
+func Must(config Configuration, err error) Configuration {
+	if err != nil {
+		panic(err)
+	}
+
+	return config
+}
+
+func Open(filename string) (Configuration, error) {
+	file, err := os.Open(filename)
+	if err != nil {
+		return Configuration{}, err
+	}
+
+	buf, err := io.ReadAll(file)
+	if err != nil {
+		return Configuration{}, err
+	}
+
+	config := Configuration{}
+
+	if err := json.Unmarshal(buf, &config); err != nil {
+		return Configuration{}, err
+	} else {
+		return config, nil
+	}
+}
diff --git a/config_example.json b/config_example.json
new file mode 100644
index 0000000..99eff96
--- /dev/null
+++ b/config_example.json
@@ -0,0 +1,10 @@
+{
+    "http": {
+        "listen": "127.0.0.1:8080",
+        "base": "http://127.0.0.1:8080"
+    },
+    "auth": {
+        "username": "jwolff",
+        "password": "changeme"
+    }
+}
diff --git a/controller/app.go b/controller/app.go
new file mode 100644
index 0000000..f145ce2
--- /dev/null
+++ b/controller/app.go
@@ -0,0 +1,39 @@
+package controller
+
+import (
+	"embed"
+	"html/template"
+	"net/http"
+
+	"drop.janw.name/config"
+	"drop.janw.name/storage"
+)
+
+//go:embed template/*
+var templateFs embed.FS
+
+type App struct {
+	storage *storage.Storage
+	tmpl    *template.Template
+	config  config.Configuration
+}
+
+func NewApp(configFilename string) *App {
+	return &App{
+		storage: storage.NewStorage(),
+		tmpl:    template.Must(template.ParseFS(templateFs, "template/*.html")),
+		config:  config.Must(config.Open(configFilename)),
+	}
+}
+
+func (app App) requireAuth(res http.ResponseWriter, req *http.Request) bool {
+	username, password, ok := req.BasicAuth()
+	if ok && username == app.config.Authentication.Username && password == app.config.Authentication.Password {
+		return true
+	}
+
+	res.Header().Add("WWW-Authenticate", "Basic realm=\"Authentication Required\", charset=\"UTF-8\"")
+	res.WriteHeader(http.StatusUnauthorized)
+
+	return false
+}
diff --git a/controller/controller.go b/controller/controller.go
new file mode 100644
index 0000000..1f28562
--- /dev/null
+++ b/controller/controller.go
@@ -0,0 +1,8 @@
+package controller
+
+import "net/http"
+
+type Controller struct {
+	GET  http.HandlerFunc
+	POST http.HandlerFunc
+}
diff --git a/controller/file.go b/controller/file.go
new file mode 100644
index 0000000..53121d5
--- /dev/null
+++ b/controller/file.go
@@ -0,0 +1,79 @@
+package controller
+
+import (
+	"fmt"
+	"io"
+	"net/http"
+	"time"
+
+	"drop.janw.name/storage"
+)
+
+const MAX_FILESIZE = (1 << 19) * 100
+
+func (app App) FilePost(res http.ResponseWriter, req *http.Request) {
+	if !app.requireAuth(res, req) {
+		return
+	}
+
+	if err := req.ParseMultipartForm(MAX_FILESIZE); err != nil {
+		panic(err)
+	}
+
+	formFile, formFileHeader, err := req.FormFile("file")
+	if err != nil {
+		panic(err)
+	}
+
+	protected := req.FormValue("protect") == "on"
+
+	fileData, err := io.ReadAll(formFile)
+	if err != nil {
+		panic(err)
+	}
+
+	file := storage.File{
+		Protected:      protected,
+		Filename:       formFileHeader.Filename,
+		Data:           fileData,
+		AvailableUntil: time.Now().Add(time.Hour * 2),
+	}
+
+	key, err := app.storage.Put(file)
+	if err != nil {
+		panic(err)
+	}
+
+	app.tmpl.ExecuteTemplate(res, "uploaded", struct {
+		DownloadURL string
+	}{
+		DownloadURL: fmt.Sprintf("%s/%s", app.config.Http.BaseAddress, key),
+	})
+}
+
+func (app App) FileGet(res http.ResponseWriter, req *http.Request) {
+	fileId := req.PathValue("file")
+
+	file, _ := app.storage.Get(fileId)
+
+	if file == nil || !file.IsAvailable() {
+		if !app.requireAuth(res, req) {
+			return
+		}
+
+		res.WriteHeader(http.StatusNotFound)
+		app.tmpl.ExecuteTemplate(res, "404", nil)
+		return
+	}
+
+	if file.Protected && !app.requireAuth(res, req) {
+		return
+	}
+
+	res.Header().Add("Content-Type", "application/octet-stream")
+	res.Header().Add("Content-Disposition", fmt.Sprintf("attachment; filename=\"%s\"", file.Filename))
+
+	if _, err := res.Write(file.Data); err != nil {
+		panic(err)
+	}
+}
diff --git a/controller/index.go b/controller/index.go
new file mode 100644
index 0000000..6f927ed
--- /dev/null
+++ b/controller/index.go
@@ -0,0 +1,13 @@
+package controller
+
+import (
+	"net/http"
+)
+
+func (app App) Index(res http.ResponseWriter, req *http.Request) {
+	if !app.requireAuth(res, req) {
+		return
+	}
+
+	app.tmpl.ExecuteTemplate(res, "index", nil)
+}
diff --git a/controller/template/404.html b/controller/template/404.html
new file mode 100644
index 0000000..fa19547
--- /dev/null
+++ b/controller/template/404.html
@@ -0,0 +1,7 @@
+{{define "404"}}
+{{template "header" .}}
+<main>
+    <h1>no such file</h1>
+</main>
+{{template "footer" .}}
+{{end}}
diff --git a/controller/template/base.html b/controller/template/base.html
new file mode 100644
index 0000000..c91245d
--- /dev/null
+++ b/controller/template/base.html
@@ -0,0 +1,49 @@
+{{define "header"}}
+<!DOCTYPE html>
+<html lang="en">
+    <head>
+        <title>drop.janw.name</title>
+        <meta charset="UTF-8">
+        <meta name="author" content="Jan Wolff">
+        <meta name="viewport" content="width=device-width, initial-scale=1.0, user-scalable=yes">
+        <link href="data:," rel="icon">
+        <style>
+            html, body {
+                padding: 0;
+                margin: 0;
+                width: 100%;
+                height: 100%;
+            }
+
+            body {
+                display: flex;
+                justify-content: center;
+                align-items: center;
+                background: #ebebeb;
+                font-family: sans-serif;
+            }
+
+            main {
+                padding: 2rem;
+                border-radius: 2rem;
+                background: #fefefe;
+            }
+
+            form {
+                display: flex;
+                flex-direction: column;
+                gap: 1rem;
+            }
+
+            progress {
+                width: 100%;
+            }
+        </style>
+    </head>
+    <body>
+{{end}}
+
+{{define "footer"}}
+    </body>
+</html>
+{{end}}
diff --git a/controller/template/index.html b/controller/template/index.html
new file mode 100644
index 0000000..f50be97
--- /dev/null
+++ b/controller/template/index.html
@@ -0,0 +1,28 @@
+{{define "index"}}
+{{template "header" .}}
+<main>
+    <h1>drop.janw.name</h1>
+    <form method="POST" action="/" enctype="multipart/form-data">
+        <div>
+            <label for="file">
+                File:
+            </label>
+            <input id="file" type="file" name="file">
+        </div>
+        <div>
+            <label for="protect">
+                Password Protect:
+            </label>
+            <input id="protect" type="checkbox" name="protect">
+        </div>
+        <div>
+            <label for="until">
+                Available Until:
+            </label>
+            <input id="until" type="datetime-local" name="until">
+        </div>
+        <input type="submit" id="upload" value="Upload">
+    </form>
+</main>
+{{template "footer" .}}
+{{end}}
diff --git a/controller/template/uploaded.html b/controller/template/uploaded.html
new file mode 100644
index 0000000..1324082
--- /dev/null
+++ b/controller/template/uploaded.html
@@ -0,0 +1,10 @@
+{{define "uploaded"}}
+{{template "header" .}}
+<main>
+    <h1>File uploaded successfully</h1>
+    <p>
+        <a href="{{.DownloadURL}}">{{.DownloadURL}}</a>
+    </p>
+</main>
+{{template "footer" .}}
+{{end}}
diff --git a/go.mod b/go.mod
new file mode 100644
index 0000000..031d11d
--- /dev/null
+++ b/go.mod
@@ -0,0 +1,3 @@
+module drop.janw.name
+
+go 1.24.7
diff --git a/main.go b/main.go
new file mode 100644
index 0000000..3800de3
--- /dev/null
+++ b/main.go
@@ -0,0 +1,66 @@
+package main
+
+import (
+	"flag"
+	"fmt"
+	"log"
+	"net/http"
+	"runtime/debug"
+
+	"drop.janw.name/controller"
+)
+
+var CONFIG_FILENAME string
+
+func registerHandler(pattern string, controller controller.Controller) {
+	http.HandleFunc(pattern, func(res http.ResponseWriter, req *http.Request) {
+		defer func() {
+			err := recover()
+			if err != nil {
+				res.WriteHeader(http.StatusInternalServerError)
+				fmt.Fprintln(res, "internal server error")
+				fmt.Fprintln(res, err)
+				fmt.Fprintln(res, string(debug.Stack()))
+			}
+		}()
+
+		var methodFunc http.HandlerFunc
+
+		switch req.Method {
+		case http.MethodGet:
+			methodFunc = controller.GET
+		case http.MethodPost:
+			methodFunc = controller.POST
+		}
+
+		log.Println(req.Method, req.RemoteAddr, req.RequestURI)
+
+		if methodFunc != nil {
+			methodFunc(res, req)
+		} else {
+			res.WriteHeader(http.StatusMethodNotAllowed)
+			fmt.Fprintln(res, "method not allowed")
+		}
+	})
+}
+
+func init() {
+	flag.StringVar(&CONFIG_FILENAME, "c", "config_example.json", "path to the configuration file")
+	flag.Parse()
+}
+
+func main() {
+	app := controller.NewApp(CONFIG_FILENAME)
+
+	registerHandler("/", controller.Controller{
+		GET:  app.Index,
+		POST: app.FilePost,
+	})
+
+	registerHandler("/{file}", controller.Controller{
+		GET: app.FileGet,
+	})
+
+	log.Println(fmt.Sprintf("serving on http://%s\n", "127.0.0.1:8080"))
+	log.Panicln(http.ListenAndServe("127.0.0.1:8080", nil))
+}
diff --git a/storage/file.go b/storage/file.go
new file mode 100644
index 0000000..6fa5070
--- /dev/null
+++ b/storage/file.go
@@ -0,0 +1,21 @@
+package storage
+
+import (
+	"bytes"
+	"time"
+)
+
+type File struct {
+	Protected      bool
+	Filename       string
+	Data           []byte
+	AvailableUntil time.Time
+}
+
+func (f File) IsAvailable() bool {
+	return time.Now().Before(f.AvailableUntil)
+}
+
+func (f File) Reader() *bytes.Reader {
+	return bytes.NewReader(f.Data)
+}
diff --git a/storage/storage.go b/storage/storage.go
new file mode 100644
index 0000000..6dc4a37
--- /dev/null
+++ b/storage/storage.go
@@ -0,0 +1,57 @@
+package storage
+
+import (
+	"crypto/rand"
+	"errors"
+	"math/big"
+	"strings"
+)
+
+var ErrNoSuchFile = errors.New("no such file")
+
+type Storage struct {
+	files map[string]File
+}
+
+func NewStorage() *Storage {
+	return &Storage{
+		files: make(map[string]File),
+	}
+}
+
+func generateKey(length uint) (string, error) {
+	key := make([]string, 0, 0)
+	alphabet := "ABCDEFGHIJKLMNOPQRSTUVWXYZ123456789abcdefghkmnpqrstuvwxyz"
+
+	for i := uint(0); i < length; i++ {
+		n, err := rand.Int(rand.Reader, big.NewInt(int64(len(alphabet))))
+
+		if err != nil {
+			return "", err
+		}
+
+		key = append(key, string(alphabet[n.Int64()]))
+	}
+
+	return strings.Join(key, ""), nil
+}
+
+func (s *Storage) Get(key string) (*File, error) {
+	if file, ok := s.files[key]; ok {
+		return &file, nil
+	} else {
+		return nil, ErrNoSuchFile
+	}
+}
+
+func (s *Storage) Put(file File) (string, error) {
+	key, err := generateKey(8)
+
+	if err != nil {
+		return "", err
+	}
+
+	s.files[key] = file
+
+	return key, nil
+}