add more error checks

There are still some cases where the input is not correctly checked, but
it is moving forward.

1 files changed, 3 insertions, 0 deletions

diff --git a/pem.go b/pem.go
index bbe2a47..2fdf3cc 100644
--- a/pem.go
+++ b/pem.go
@@ -35,6 +35,9 @@ func parseFile(file io.Reader) (pemMap, error) {
 	if err != nil {
 		return nil, err
 	}
+	if len(raw) == 0 {
+		return nil, fmt.Errorf("file is empty")
+	}
 	return parsePem(raw)
 }