From 2d7aadc689346f46613ce5dc7010f72ed8eb0baf Mon Sep 17 00:00:00 2001
From: terrafrost <terrafrost@php.net>
Date: Fri, 12 Oct 2018 23:04:57 -0500
Subject: [PATCH] Hash: tweaks to hash pre-computation

---
 phpseclib/Crypt/Hash.php | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/phpseclib/Crypt/Hash.php b/phpseclib/Crypt/Hash.php
index 65c8449c..1042463f 100644
--- a/phpseclib/Crypt/Hash.php
+++ b/phpseclib/Crypt/Hash.php
@@ -126,6 +126,15 @@ class Crypt_Hash
      */
     var $key = false;
 
+    /**
+     * Computed Key
+     *
+     * @see self::_computeKey()
+     * @var string
+     * @access private
+     */
+    var $computedKey = false;
+
     /**
      * Outer XOR (Internal HMAC)
      *
@@ -209,6 +218,11 @@ class Crypt_Hash
      */
     function _computeKey()
     {
+        if ($this->key === false) {
+            $this->computedKey = false;
+            return;
+        }
+
         if (strlen($this->key) <= $this->b) {
             $this->computedKey = $this->key;
             return;