diff --git a/phpunit.xml b/phpunit.xml
index b3ac75ad..e16564c3 100644
--- a/phpunit.xml
+++ b/phpunit.xml
@@ -1,9 +1,9 @@
+  <!-- restrictWarnings="true" -->
 <phpunit
   bootstrap="test/unit/bootstrap.php"
   failOnWarning="true"
   failOnDeprecation="true"
   failOnNotice="true"
-  restrictWarnings="true"
 >
   <testsuites>
     <testsuite name="unit">
diff --git a/resources/lib/UnitySite.php b/resources/lib/UnitySite.php
index 7ad484ff..50151e57 100644
--- a/resources/lib/UnitySite.php
+++ b/resources/lib/UnitySite.php
@@ -52,6 +52,18 @@ public static function getGithubKeys($username)
 
     public static function testValidSSHKey($key_str)
     {
+        $key_str = trim($key_str);
+        if ($key_str == "") {
+            return false;
+        }
+        // PHP warning when key_str is digits: Attempt to read property "keys" on int
+        if (preg_match("/^[0-9]+$/", $key_str)) {
+            return false;
+        }
+        // PHP warning when key_str is JSON: Undefined property: stdClass::$keys
+        if (!is_null(@json_decode($key_str))) {
+            return false;
+        }
         try {
             PublicKeyLoader::load($key_str);
             return true;
diff --git a/webroot/js/ajax/ssh_validate.php b/webroot/js/ajax/ssh_validate.php
index 7180defb..2fd32173 100644
--- a/webroot/js/ajax/ssh_validate.php
+++ b/webroot/js/ajax/ssh_validate.php
@@ -2,11 +2,7 @@
 
 require "../../../resources/autoload.php";
 
+use UnityWebPortal\lib\UnitySite;
 use phpseclib3\Crypt\PublicKeyLoader;
 
-try {
-    PublicKeyLoader::load($_POST['key'], $password = false);
-    echo "true";
-} catch (Exception $e) {
-    echo "false";
-}
+echo (UnitySite::testValidSSHKey($_POST["key"]) ? "true" : "false");