From 0cc01d33552c95b32339d310774999301ac3b799 Mon Sep 17 00:00:00 2001
From: Djamil Legato <djamil@djamil.it>
Date: Tue, 27 Sep 2016 11:29:59 -0700
Subject: [PATCH] Added new `Licenses::validate` method to validate the format
 of a License

---
 system/src/Grav/Common/GPM/Licenses.php | 33 +++++++++++++++++++++++++
 1 file changed, 33 insertions(+)

diff --git a/system/src/Grav/Common/GPM/Licenses.php b/system/src/Grav/Common/GPM/Licenses.php
index 510711d35..9a8798595 100644
--- a/system/src/Grav/Common/GPM/Licenses.php
+++ b/system/src/Grav/Common/GPM/Licenses.php
@@ -11,8 +11,21 @@ namespace Grav\Common\GPM;
 use Grav\Common\Grav;
 use RocketTheme\Toolbox\File\YamlFile;
 
+/**
+ * Class Licenses
+ *
+ * @package Grav\Common\GPM
+ */
 class Licenses
 {
+
+    /**
+     * Regex to validate the format of a License
+     *
+     * @var string
+     */
+    protected static $regex = '^(?:[A-F0-9]{8}-){3}(?:[A-F0-9]{8}){1}$';
+
     /**
      * Returns the license for a Premium package
      *
@@ -66,6 +79,26 @@ class Licenses
         return $data['licenses'][$slug];
     }
 
+
+    /**
+     * Validates the License format
+     *
+     * @param $license
+     *
+     * @return bool
+     */
+    public static function validate($license = null)
+    {
+        if (!is_string($license)) {
+            return false;
+        }
+
+        return preg_match('#' . self::$regex. '#', $license);
+    }
+
+    /**
+     * @return string
+     */
     protected static function getLicensePath()
     {
         $path = Grav::instance()['locator']->findResource('user://data') . '/licenses.yaml';