Fixes #8584, #8654, #8727 - fixes and improvements for saml (#8795)

* Let onelogin/php-saml know to use 'X-Forwarded-*' headers if it is from a trusted proxy

* Gracefully handle the case where openssl_csr_new fails when openssl.cnf is invalid/missing

* Improve ui of saml sp metadata by displaying it's url and a download button

app/Http/Controllers/Auth/SamlController.php

@@ -53,8 +53,10 @@ class SamlController extends Controller
         if (empty($metadata)) {
             return response()->view('errors.403', [], 403);
         }
-
-        return response($metadata)->header('Content-Type', 'text/xml');
+    
+        return response()->streamDownload(function () use ($metadata) {
+            echo $metadata;
+        }, 'snipe-it-metadata.xml', ['Content-Type' => 'text/xml']);
     }
 
     /**