sanitize mime types

cmd/simple-S3-cache/main.go

@@ -7,6 +7,7 @@ import (
 	"time"
 
 	"github.com/i5heu/simple-S3-cache/internal/config"
+	"github.com/i5heu/simple-S3-cache/internal/helper"
 	"github.com/i5heu/simple-S3-cache/internal/log"
 	"github.com/i5heu/simple-S3-cache/internal/ramCache"
 	"github.com/i5heu/simple-S3-cache/internal/storageCache"
@@ -94,8 +95,9 @@ func (h *Handler) handler(ctx *fasthttp.RequestCtx) {
 	}
 
 	size = uint(len(bytes))
-	h.dataStoreRAM.CacheData(url, bytes, res.Header.Get("Content-Type"))
-	h.dataStoreStorage.CacheData(url, bytes, res.Header.Get("Content-Type"))
-	ctx.Response.Header.Set("Content-Type", res.Header.Get("Content-Type"))
+	sanitizedMime := helper.SanitizeMimeType(res.Header.Get("Content-Type"))
+	h.dataStoreRAM.CacheData(url, bytes, sanitizedMime)
+	h.dataStoreStorage.CacheData(url, bytes, sanitizedMime)
+	ctx.Response.Header.Set("Content-Type", sanitizedMime)
 	ctx.Response.SetBody(bytes)
 }

internal/helper/sanitize.go

@@ -0,0 +1,21 @@
+package helper
+
+import "unicode"
+
+func SanitizeMimeType(mime string) string {
+	if mime == "" {
+		return "application/octet-stream"
+	}
+	if len([]byte(mime)) > 256 {
+		return "application/octet-stream"
+	}
+
+	// check if mime is only ascii
+	for _, rune := range mime {
+		if unicode.IsPrint(rune) == false {
+			return "application/octet-stream"
+		}
+	}
+
+	return mime
+}