From 229ddd54a827f204cd85946d8ae4a889cbcf0fdb Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?St=C3=A9phane=20Depierrepont=20aka=20Toorop?=
 <toorop@toorop.fr>
Date: Tue, 20 Oct 2015 12:29:39 +0200
Subject: [PATCH] bugfix check returns of pem.Decode

---
 dkim.go | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/dkim.go b/dkim.go
index 163da16..fa70951 100644
--- a/dkim.go
+++ b/dkim.go
@@ -106,6 +106,9 @@ func Sign(email *[]byte, options SigOptions) error {
 		return ErrSignPrivateKeyRequired
 	}
 	d, _ := pem.Decode(options.PrivateKey)
+	if d == nil {
+		return ErrCandNotParsePrivateKey
+	}
 	key, err := x509.ParsePKCS1PrivateKey(d.Bytes)
 	if err != nil {
 		return ErrCandNotParsePrivateKey