diff --git a/coolq/bot.go b/coolq/bot.go
index ba120bd..979bfa3 100644
--- a/coolq/bot.go
+++ b/coolq/bot.go
@@ -135,6 +135,7 @@ func (bot *CQBot) UploadLocalImageAsPrivate(userId int64, img *LocalImageElement
 	if err != nil {
 		return nil, err
 	}
+	defer f.Close()
 	return bot.Client.UploadPrivateImage(userId, f)
 }
 
diff --git a/coolq/cqcode.go b/coolq/cqcode.go
index 0475e01..6e3023f 100644
--- a/coolq/cqcode.go
+++ b/coolq/cqcode.go
@@ -810,7 +810,7 @@ func (bot *CQBot) ToElement(t string, d map[string]string, group bool) (m interf
 		_, err = v.video.Read(header)
 		if !bytes.Equal(header, []byte{0x66, 0x74, 0x79, 0x70}) { // ftyp
 			_, _ = v.video.Seek(0, io.SeekStart)
-			hash, _ := utils.GetMd5AndLength(v.video)
+			hash, _ := utils.ComputeMd5AndLength(v.video)
 			cacheFile := path.Join(global.CACHE_PATH, hex.EncodeToString(hash[:])+".mp4")
 			if global.PathExists(cacheFile) {
 				goto ok
diff --git a/global/net.go b/global/net.go
index 715b1a0..7bdf83f 100644
--- a/global/net.go
+++ b/global/net.go
@@ -23,7 +23,7 @@ import (
 
 var (
 	client = &http.Client{
-		Timeout: time.Second * 30,
+		Timeout: time.Second * 120,
 		Transport: &http.Transport{
 			Proxy: func(request *http.Request) (u *url.URL, e error) {
 				if Proxy == "" {
@@ -47,6 +47,8 @@ var (
 	Proxy string
 
 	ErrOverSize = errors.New("oversize")
+
+	UserAgent = "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/87.0.4280.88 Safari/537.36 Edg/87.0.664.66"
 )
 
 func GetBytes(url string) ([]byte, error) {
@@ -54,7 +56,7 @@ func GetBytes(url string) ([]byte, error) {
 	if err != nil {
 		return nil, err
 	}
-	req.Header["User-Agent"] = []string{"Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/83.0.4103.116 Safari/537.36 Edg/83.0.478.61"}
+	req.Header["User-Agent"] = []string{UserAgent}
 	resp, err := client.Do(req)
 	if err != nil {
 		return nil, err
@@ -74,7 +76,7 @@ func GetBytes(url string) ([]byte, error) {
 	return body, nil
 }
 
-func DownloadFile(url, path string, limit int64) error {
+func DownloadFile(url, path string, limit int64, headers map[string]string) error {
 	file, err := os.OpenFile(path, os.O_WRONLY|os.O_CREATE, 0666)
 	if err != nil {
 		return err
@@ -84,6 +86,14 @@ func DownloadFile(url, path string, limit int64) error {
 	if err != nil {
 		return err
 	}
+	if headers != nil {
+		for k, v := range headers {
+			req.Header.Set(k, v)
+		}
+	}
+	if _, ok := headers["User-Agent"]; ok {
+		req.Header["User-Agent"] = []string{UserAgent}
+	}
 	resp, err := client.Do(req)
 	if err != nil {
 		return err
@@ -101,7 +111,7 @@ func DownloadFile(url, path string, limit int64) error {
 
 func DownloadFileMultiThreading(url, path string, limit int64, threadCount int, headers map[string]string) error {
 	if threadCount < 2 {
-		return DownloadFile(url, path, limit)
+		return DownloadFile(url, path, limit, headers)
 	}
 	type BlockMetaData struct {
 		BeginOffset    int64
@@ -133,6 +143,9 @@ func DownloadFileMultiThreading(url, path string, limit int64, threadCount int,
 				req.Header.Set(k, v)
 			}
 		}
+		if _, ok := headers["User-Agent"]; ok {
+			req.Header["User-Agent"] = []string{UserAgent}
+		}
 		req.Header.Set("range", "bytes=0-")
 		resp, err := client.Do(req)
 		if err != nil {
@@ -194,6 +207,9 @@ func DownloadFileMultiThreading(url, path string, limit int64, threadCount int,
 				req.Header.Set(k, v)
 			}
 		}
+		if _, ok := headers["User-Agent"]; ok {
+			req.Header["User-Agent"] = []string{UserAgent}
+		}
 		req.Header.Set("range", "bytes="+strconv.FormatInt(block.BeginOffset, 10)+"-"+strconv.FormatInt(block.EndOffset, 10))
 		resp, err := client.Do(req)
 		if err != nil {
diff --git a/go.mod b/go.mod
index 596999c..edf8397 100644
--- a/go.mod
+++ b/go.mod
@@ -3,7 +3,7 @@ module github.com/Mrs4s/go-cqhttp
 go 1.15
 
 require (
-	github.com/Mrs4s/MiraiGo v0.0.0-20210108162828-29f670b7201f
+	github.com/Mrs4s/MiraiGo v0.0.0-20210108202403-fb15970f2606
 	github.com/dustin/go-humanize v1.0.0
 	github.com/gin-contrib/pprof v1.3.0
 	github.com/gin-gonic/gin v1.6.3
diff --git a/go.sum b/go.sum
index d70f8d8..fc51ca3 100644
--- a/go.sum
+++ b/go.sum
@@ -1,7 +1,7 @@
 cloud.google.com/go v0.26.0/go.mod h1:aQUYkXzVsufM+DwF1aE+0xfcU+56JwCaLick0ClmMTw=
 github.com/BurntSushi/toml v0.3.1/go.mod h1:xHWCNGjB5oqiDr8zfno3MHue2Ht5sIBksp03qcyfWMU=
-github.com/Mrs4s/MiraiGo v0.0.0-20210108162828-29f670b7201f h1:I+rP4wxfLXZw6UpYCeNXWTItmeO4FPw1ZUrRjTVbAME=
-github.com/Mrs4s/MiraiGo v0.0.0-20210108162828-29f670b7201f/go.mod h1:HW2e375lCQiRwtuA/LV6ZVTsi7co1TRfBn+L5Ow77Bo=
+github.com/Mrs4s/MiraiGo v0.0.0-20210108202403-fb15970f2606 h1:SD8GLZcVmgbvYiojJhv698AJNVB1YHqx2QI63Qz4zHo=
+github.com/Mrs4s/MiraiGo v0.0.0-20210108202403-fb15970f2606/go.mod h1:HW2e375lCQiRwtuA/LV6ZVTsi7co1TRfBn+L5Ow77Bo=
 github.com/census-instrumentation/opencensus-proto v0.2.1/go.mod h1:f6KPmirojxKA12rnyqOA5BBL4O983OfeGPqjHWSTneU=
 github.com/client9/misspell v0.3.4/go.mod h1:qj6jICC3Q7zFZvVWo7KLAzC3yx5G7kyvSDkc90ppPyw=
 github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=