Merge pull request #137 from savel999/master

match xls formats: biff5,biff8(11),biff8(12)
h2non · Oct 27, 2023 · dd4cc89 · dd4cc89
2 parents 462b61f + 99ad8a4
commit dd4cc89
Showing 1 changed file with 10 additions and 7 deletions.
diff --git a/matchers/document.go b/matchers/document.go
@@ -64,14 +64,17 @@ func Docx(buf []byte) bool {
 
 func Xls(buf []byte) bool {
 	if len(buf) > 513 {
-		return buf[0] == 0xD0 && buf[1] == 0xCF &&
-			buf[2] == 0x11 && buf[3] == 0xE0 &&
-			buf[512] == 0x09 && buf[513] == 0x08
-	} else {
-		return len(buf) > 3 &&
-			buf[0] == 0xD0 && buf[1] == 0xCF &&
-			buf[2] == 0x11 && buf[3] == 0xE0
+		isMSOfficeBFF := buf[0] == 0xD0 && buf[1] == 0xCF && buf[2] == 0x11 && buf[3] == 0xE0
+
+		switch {
+		case isMSOfficeBFF && buf[512] == 0x09 && buf[513] == 0x08: // BIFF5 && BIFF12(12)
+			return true
+		case isMSOfficeBFF && buf[512] == 0xFD && buf[513] == 0xFF: // BIFF12(11)
+			return true
+		}
 	}
+
+	return false
 }
 
 func Xlsx(buf []byte) bool {