diff --git a/server/common/crypto.go b/server/common/crypto.go
index 09465a91..0c801289 100644
--- a/server/common/crypto.go
+++ b/server/common/crypto.go
@@ -8,6 +8,7 @@ import (
 	"crypto/rand"
 	"crypto/sha256"
 	"encoding/base64"
+	"hash/fnv"
 	"io"
 	"io/ioutil"
 	mathrand "math/rand"
@@ -62,6 +63,24 @@ func Hash(str string, n int) string {
 	return h
 }
 
+func QuickHash(str string, n int) string {
+	hash := fnv.New32()
+	hash.Write([]byte(str))
+	d := string(hash.Sum(nil))
+	h := ""
+	for i:=0; i<len(d); i++ {
+		if n > 0 && len(h) >= n {
+			break
+		}
+		h += ReversedBaseChange(Letters, int(d[i]))
+	}
+
+	if len(h) > n {
+		return h[0:len(h) - 1]
+	}
+	return h
+}
+
 func ReversedBaseChange(alphabet []rune, i int) string {
 	str := ""
 	for {
diff --git a/server/common/files.go b/server/common/files.go
index be8be21d..1039d02a 100644
--- a/server/common/files.go
+++ b/server/common/files.go
@@ -6,7 +6,12 @@ import (
 	"strings"
 )
 
+var MOCK_CURRENT_DIR string
+
 func GetCurrentDir() string {
+	if MOCK_CURRENT_DIR != "" {
+		return MOCK_CURRENT_DIR
+	}
 	ex, _ := os.Executable()
 	return filepath.Dir(ex)
 }
diff --git a/server/common/response.go b/server/common/response.go
index ba82ba0d..34c8f5c0 100644
--- a/server/common/response.go
+++ b/server/common/response.go
@@ -33,6 +33,17 @@ func SendSuccessResult(res http.ResponseWriter, data interface{}) {
 	encoder.Encode(APISuccessResult{"ok", data})
 }
 
+func SendSuccessResultWithEtag(res http.ResponseWriter, req *http.Request, data interface{}) {
+	json, _ := json.Marshal(APISuccessResult{"ok", data})
+	hash := QuickHash(string(json), 20)
+	if req.Header.Get("If-None-Match") == hash {
+		res.WriteHeader(http.StatusNotModified)
+		return
+	}
+	res.Header().Set("Etag", hash)
+	res.Write(json)
+}
+
 func SendSuccessResults(res http.ResponseWriter, data interface{}) {
 	encoder := json.NewEncoder(res)
 	encoder.SetEscapeHTML(false)
diff --git a/server/ctrl/admin.go b/server/ctrl/admin.go
index e4619eff..f960b01a 100644
--- a/server/ctrl/admin.go
+++ b/server/ctrl/admin.go
@@ -76,21 +76,12 @@ func AdminSessionAuthenticate(ctx App, res http.ResponseWriter, req *http.Reques
 	SendSuccessResult(res, true)
 }
 
-
-func AdminBackend(ctx App, res http.ResponseWriter, req *http.Request) {
-	backends := make(map[string]Form)
+func AdminBackend(ctx App, res http.ResponseWriter, req *http.Request) {	
 	drivers := Backend.Drivers()
+	backends := make(map[string]Form, len(drivers))
 	for key := range drivers {
 		backends[key] = drivers[key].LoginForm()
 	}
-
-	if c, err := json.Marshal(backends); err == nil {
-		hash := Hash(string(c), 20)
-		if req.Header.Get("If-None-Match") == hash {
-			res.WriteHeader(http.StatusNotModified)
-			return
-		}
-		res.Header().Set("Etag", hash)
-	}
-	SendSuccessResult(res, backends)
+	SendSuccessResultWithEtag(res, req, backends)
+	return
 }
diff --git a/server/ctrl/config.go b/server/ctrl/config.go
index 15c450d7..652d6dd3 100644
--- a/server/ctrl/config.go
+++ b/server/ctrl/config.go
@@ -1,7 +1,6 @@
 package ctrl
 
 import (
-	"encoding/json"
 	. "github.com/mickael-kerjean/filestash/server/common"
 	"io"
 	"io/ioutil"
@@ -14,10 +13,11 @@ import (
 var (
 	logpath = filepath.Join(GetCurrentDir(), LOG_PATH, "access.log")
 	cachepath = filepath.Join(GetCurrentDir(), CONFIG_PATH, "config.json")
+	pluginpath = filepath.Join(GetCurrentDir(), PLUGIN_PATH)
 )
 
 func FetchPluginsHandler(ctx App, res http.ResponseWriter, req *http.Request) {
-	f, err := os.OpenFile(filepath.Join(GetCurrentDir(), PLUGIN_PATH), os.O_RDONLY, os.ModePerm)
+	f, err := os.OpenFile(pluginpath, os.O_RDONLY, os.ModePerm)
 	if err != nil {
 		SendErrorResult(res, err)
 		return
@@ -90,14 +90,5 @@ func PrivateConfigUpdateHandler(ctx App, res http.ResponseWriter, req *http.Requ
 
 func PublicConfigHandler(ctx App, res http.ResponseWriter, req *http.Request) {
 	cfg := Config.Export()
-
-	if c, err := json.Marshal(cfg); err == nil {
-		hash := Hash(string(c), 20)
-		if req.Header.Get("If-None-Match") == hash {
-			res.WriteHeader(http.StatusNotModified)
-			return
-		}
-		res.Header().Set("Etag", hash)
-	}
-	SendSuccessResult(res, cfg)
+	SendSuccessResultWithEtag(res, req, cfg)
 }
diff --git a/server/ctrl/files.go b/server/ctrl/files.go
index c2a627c6..c8d769ae 100644
--- a/server/ctrl/files.go
+++ b/server/ctrl/files.go
@@ -1,7 +1,7 @@
 package ctrl
 
 import (
-	"encoding/json"
+	"fmt"
 	. "github.com/mickael-kerjean/filestash/server/common"
 	"github.com/mickael-kerjean/filestash/server/model"
 	"io"
@@ -19,13 +19,12 @@ type FileInfo struct {
 }
 
 func FileLs(ctx App, res http.ResponseWriter, req *http.Request) {
-	var files []FileInfo = make([]FileInfo, 0)
 	if model.CanRead(&ctx) == false {
 		if model.CanUpload(&ctx) == false {
 			SendErrorResult(res, NewError("Permission denied", 403))
 			return
 		}
-		SendSuccessResults(res, files)
+		SendSuccessResults(res, make([]FileInfo, 0))
 		return
 	}
 	path, err := pathBuilder(ctx, req.URL.Query().Get("path"))
@@ -40,21 +39,23 @@ func FileLs(ctx App, res http.ResponseWriter, req *http.Request) {
 		return
 	}
 
-	for _, entry := range entries {
-		f := FileInfo{
-			Name: entry.Name(),
-			Size: entry.Size(),
+	files := make([]FileInfo, len(entries))
+	etag := fmt.Sprintf("%d", len(entries)) + path
+	for i:=0; i<len(entries); i++ {
+		etag += files[i].Name
+		files[i] = FileInfo{
+			Name: entries[i].Name(),
+			Size: entries[i].Size(),
 			Time: func(t time.Time) int64 {
 				return t.UnixNano() / int64(time.Millisecond)
-			}(entry.ModTime()),
+			}(entries[i].ModTime()),
 			Type: func(isDir bool) string {
 				if isDir == true {
 					return "directory"
 				}
 				return "file"
-			}(entry.IsDir()),
+			}(entries[i].IsDir()),
 		}
-		files = append(files, f)
 	}
 
 	var perms Metadata = Metadata{}
@@ -79,22 +80,12 @@ func FileLs(ctx App, res http.ResponseWriter, req *http.Request) {
 		perms.CanShare = NewBool(false)
 	}
 
-	etag := func() string {
-		tmp := struct {
-			Tmp0 interface{}
-			Tmp1 interface{}
-		}{ files, perms }
-		if j, err := json.Marshal(tmp); err == nil {
-			return Hash(string(j), 20)
-		}
-		return ""
-	}()
+	etag = QuickHash(etag, 20)
+	res.Header().Set("Etag", etag)
 	if etag != "" && req.Header.Get("If-None-Match") == etag {
 		res.WriteHeader(http.StatusNotModified)
 		return
 	}
-	res.Header().Set("Etag", etag)
-
 	SendSuccessResultsWithMetadata(res, files, perms)
 }
 
diff --git a/server/ctrl/static.go b/server/ctrl/static.go
index b3c14246..91f22085 100644
--- a/server/ctrl/static.go
+++ b/server/ctrl/static.go
@@ -1,9 +1,8 @@
 package ctrl
 
 import (
-	"crypto/md5"
-	"encoding/base32"
 	. "github.com/mickael-kerjean/filestash/server/common"
+	"fmt"
 	"io"
 	"text/template"
 	"net/http"
@@ -12,12 +11,12 @@ import (
 	"strings"
 )
 
-var ETAGS SafeMapStringString = NewSafeMapStringString()
+var ETAGS     SafeMapStringString = NewSafeMapStringString()
 
 func StaticHandler(_path string) func(App, http.ResponseWriter, *http.Request) {
 	return func(ctx App, res http.ResponseWriter, req *http.Request) {
+		var base string = GetAbsolutePath(_path)
 		var srcPath string
-		base := GetAbsolutePath(_path)
 		if srcPath = JoinPath(base, req.URL.Path); srcPath == base {
 			http.NotFound(res, req)
 			return
@@ -93,11 +92,12 @@ func hashFile (path string, n int) string {
 		return ""
 	}
 	defer f.Close()
-	h := md5.New()
-	if _, err := io.Copy(h, f); err != nil {
-		return ""
+
+	stat, err := f.Stat()
+	if err != nil {
+		return "UNKNOWN"
 	}
-	return base32.HexEncoding.EncodeToString(h.Sum(nil))[:n]
+	return QuickHash(fmt.Sprintf("%s %d %d %s", path, stat.Size(), stat.Mode(), stat.ModTime()), n)
 }
 
 func ServeFile(res http.ResponseWriter, req *http.Request, filePath string) {
@@ -105,7 +105,7 @@ func ServeFile(res http.ResponseWriter, req *http.Request, filePath string) {
 	tags := ETAGS.Gets(filePath, zFilePath)
 	etagNormal := tags[0]
 	etagGzip := tags[1]
-	
+
 	if req.Header.Get("If-None-Match") != "" {
 		browserTag := req.Header.Get("If-None-Match")
 		if browserTag == etagNormal {
@@ -128,6 +128,7 @@ func ServeFile(res http.ResponseWriter, req *http.Request, filePath string) {
 				head.Set("Etag", etagGzip)
 			}
 			io.Copy(res, file)
+			file.Close()
 			return
 		}
 	}
@@ -145,4 +146,5 @@ func ServeFile(res http.ResponseWriter, req *http.Request, filePath string) {
 		head.Set("Etag", etagNormal)
 	}
 	io.Copy(res, file)
+	file.Close()
 }
diff --git a/server/middleware/index.go b/server/middleware/index.go
index c5f58072..ce5b8d97 100644
--- a/server/middleware/index.go
+++ b/server/middleware/index.go
@@ -20,7 +20,9 @@ func NewMiddlewareChain(fn func(App, http.ResponseWriter, *http.Request), m []Mi
 			f = m[i](f)
 		}
 		f(app, &resw, req)
-		req.Body.Close()
+		if req.Body != nil {
+			req.Body.Close()
+		}
 		go Logger(app, &resw, req)
 	}
 }