fix file naming sanitisation

internal/file/handlers.go

@@ -1,6 +1,7 @@
 package file
 
 import (
+	"ResendIt/internal/util"
 	"fmt"
 	"net/http"
 	"path/filepath"
@@ -77,27 +78,12 @@ func (h *Handler) View(c *gin.Context) {
 		c.HTML(http.StatusOK, "fileNotFound.html", nil)
 		return
 	}
-
-	c.Header("Content-Disposition", fmt.Sprintf(`inline; filename="%s"`, record.Filename))
+	name := util.SafeFilename(record.Filename)
+	c.Header("Content-Disposition", fmt.Sprintf(`inline; filename="%s"`, name))
 	c.Header("X-Content-Type-Options", "nosniff")
 	c.File(record.Path)
 }
 
-func safeFilename(name string) string {
-	// keep it simple: drop control chars and quotes
-	out := make([]rune, 0, len(name))
-	for _, r := range name {
-		if r < 32 || r == 127 || r == '"' || r == '\\' {
-			continue
-		}
-		out = append(out, r)
-	}
-	if len(out) == 0 {
-		return "file"
-	}
-	return string(out)
-}
-
 func isXSSRisk(filename string) bool {
 	ext := filepath.Ext(filename)
 	switch ext {
@@ -116,8 +102,8 @@ func (h *Handler) Download(c *gin.Context) {
 		c.HTML(http.StatusOK, "fileNotFound.html", nil)
 		return
 	}
-
-	c.Header("Content-Disposition", fmt.Sprintf(`inline; filename="%s"`, record.Filename))
+	name := util.SafeFilename(record.Filename)
+	c.Header("Content-Disposition", fmt.Sprintf(`inline; filename="%s"`, name))
 	c.Header("X-Content-Type-Options", "nosniff")
 	//c.Header("Content-Security-Policy", "default-src 'none'; img-src 'self'; media-src 'self'; script-src 'none'; style-src 'none';")
 	//c.Header("Content-Type", "application/octet-stream")

internal/file/upload_multi.go

@@ -26,8 +26,8 @@ func (h *Handler) UploadMulti(c *gin.Context) {
 		c.JSON(http.StatusBadRequest, gin.H{"error": "missing files"})
 		return
 	}
-	if len(files) > 10 {
-		c.JSON(http.StatusBadRequest, gin.H{"error": "too many files (max 10)"})
+	if len(files) > 50 {
+		c.JSON(http.StatusBadRequest, gin.H{"error": "too many files (max 50)"})
 		return
 	}
 

internal/file/zip.go

@@ -3,11 +3,9 @@ package file
 import (
 	"ResendIt/internal/util"
 	"archive/zip"
-	"crypto/rand"
 	"errors"
 	"fmt"
 	"io"
-	"math/big"
 	"mime/multipart"
 	"os"
 	"path/filepath"
@@ -39,17 +37,6 @@ func dedupeName(name string, seen map[string]int) string {
 	return fmt.Sprintf("%s (%d)%s", base, seen[name], ext)
 }
 
-func randIndex(n int) int {
-	if n <= 0 {
-		return 0
-	}
-	x, err := rand.Int(rand.Reader, big.NewInt(int64(n)))
-	if err != nil {
-		return 0
-	}
-	return int(x.Int64())
-}
-
 func cuteZipName(fileCount int) string {
 	adjective := util.RandomAdjective()
 	verb := util.RandomVerb()

internal/util/util.go

@@ -1,6 +1,9 @@
 package util
 
-import "fmt"
+import (
+	"fmt"
+	"strings"
+)
 
 func HumanSize(size int64) string {
 	const unit = 1024
@@ -17,3 +20,24 @@ func HumanSize(size int64) string {
 		"KMGTPE"[exp],
 	)
 }
+
+func SafeFilename(name string) string {
+	name = strings.TrimSpace(name)
+
+	out := make([]rune, 0, len(name))
+	for _, r := range name {
+		// block control chars (incl CR/LF/TAB), DEL, quotes, backslash
+		if r < 32 || r == 127 || r == '"' || r == '\\' {
+			continue
+		}
+		out = append(out, r)
+	}
+	if len(out) == 0 {
+		return "file"
+	}
+	// optional: cap length
+	if len(out) > 200 {
+		out = out[:200]
+	}
+	return string(out)
+}