feat: add Authorization

cmd/main.go

@@ -3,6 +3,9 @@ package main
 import (
 	"bytes"
 	"crypto/md5"
+	"crypto/rand"
+	"encoding/hex"
+	"errors"
 	"flag"
 	"io"
 	"net/http"
@@ -23,10 +26,32 @@ type imagebody struct {
 	dat []byte
 }
 
+var (
+	errInvalidTokenLength = errors.New("invalid token length")
+	errInvalidToken       = errors.New("invalid token")
+)
+
 func main() {
 	cachetime := flag.Uint("t", 60, "cache time (s)")
 	endpoint := flag.String("e", "127.0.0.1:8000", "listening endpoint")
+	var tok [32]byte
+	_, err := rand.Read(tok[:])
+	if err != nil {
+		panic(err)
+	}
+	token := flag.String("k", hex.EncodeToString(tok[:]), "put/delete token")
 	flag.Parse()
+	if len(*token) != 64 {
+		panic(errInvalidTokenLength)
+	}
+	n, err := hex.Decode(tok[:], imoto.StringToBytes(*token))
+	if err != nil {
+		panic(err)
+	}
+	if n != 32 {
+		panic(errInvalidToken)
+	}
+	logrus.Infoln("listening to", *endpoint, "with token", hex.EncodeToString(tok[:]))
 	imgcache = ttl.NewCache[uint64, *imagebody](time.Second * time.Duration(*cachetime))
 	http.HandleFunc("/", func(w http.ResponseWriter, r *http.Request) {
 		m, err := imoto.GetMD5(r.URL.Path)
@@ -54,6 +79,15 @@ func main() {
 			w.Header().Set("Content-Type", "image/"+img.typ)
 			_, _ = w.Write(img.dat)
 		case http.MethodPut:
+			err := checktoken(&tok, r)
+			if err != nil {
+				http.Error(w, "400 Bad Request: "+err.Error(), http.StatusBadRequest)
+				return
+			}
+			if imgcache.Get(p) != nil {
+				w.WriteHeader(http.StatusOK)
+				return
+			}
 			data, err := io.ReadAll(r.Body)
 			if err != nil {
 				http.Error(w, "500 Internal Server Error: "+err.Error(), http.StatusInternalServerError)
@@ -76,6 +110,11 @@ func main() {
 			})
 			w.WriteHeader(http.StatusOK)
 		case http.MethodDelete:
+			err := checktoken(&tok, r)
+			if err != nil {
+				http.Error(w, "400 Bad Request: "+err.Error(), http.StatusBadRequest)
+				return
+			}
 			img := imgcache.Get(p)
 			if img == nil {
 				w.WriteHeader(http.StatusNotFound)
@@ -95,3 +134,18 @@ func main() {
 	})
 	logrus.Errorln(http.ListenAndServe(*endpoint, nil))
 }
+
+func checktoken(tok *[32]byte, r *http.Request) error {
+	t := r.Header.Get("Authorization")
+	if len(t) != 64 {
+		return errInvalidTokenLength
+	}
+	usrtok, err := hex.DecodeString(t)
+	if err != nil {
+		return err
+	}
+	if !bytes.Equal(usrtok, tok[:]) {
+		return errInvalidToken
+	}
+	return nil
+}