update zip

Author: wuriyanto48

signature.go

@@ -26,6 +26,8 @@ var (
 	PDF        = []byte{0x25, 0x50, 0x44, 0x46}
 	RAR        = []byte{0x52, 0x61, 0x72, 0x21, 0x1A, 0x07, 0x00}
 	GZIP       = []byte{0x1F, 0x8B, 0x08}
-	ZIP        = []byte{0x50, 0x4B, 0x03, 0x04}
+	ZIP_0      = []byte{0x50, 0x4B, 0x03, 0x04}
+	ZIP_1      = []byte{0x50, 0x4B, 0x05, 0x06}
+	ZIP_2      = []byte{0x50, 0x4B, 0x07, 0x08}
 	WEBP       = []byte{0x52, 0x49, 0x46, 0x46}
 )

validator.go

@@ -360,15 +360,17 @@ func IsGzip(r io.ReadSeeker) bool {
 
 // IsZip function will return true if File is a valid ZIP
 func IsZip(r io.ReadSeeker) bool {
-	l := len(ZIP)
+	l := len(ZIP_0)
 
 	buff, err := readUntil(l, r)
 	if err != nil {
 		return false
 	}
 
-	valid := bytes.Compare(ZIP, buff)
-	if valid != 0 {
+	valid_zip_0 := bytes.Compare(ZIP_0, buff)
+	valid_zip_1 := bytes.Compare(ZIP_0, buff)
+	valid_zip_2 := bytes.Compare(ZIP_2, buff)
+	if valid_zip_0 != 0 && valid_zip_1 != 0 && valid_zip_2 != 0 {
 		return false
 	}