Fix CVE-2019-18887 issue in symfony/http-kernel

composer.json

@@ -145,6 +145,7 @@
             "Barryvdh\\Debugbar\\": "overrides/barryvdh/laravel-debugbar/src/",
             "Barryvdh\\Debugbar\\DataFormatter\\": "overrides/barryvdh/laravel-debugbar/src/DataFormatter/",
             "Symfony\\Component\\Process\\": "overrides/symfony/process/",
+            "Symfony\\Component\\HttpKernel\\": "overrides/symfony/http-kernel/",
             "Symfony\\Component\\HttpKernel\\Exception\\": "overrides/symfony/http-kernel/Exception/",
             "Symfony\\Component\\HttpKernel\\HttpCache\\": "overrides/symfony/http-kernel/HttpCache/",
             "Spatie\\String\\": "overrides/spatie/string/src/",
@@ -256,6 +257,7 @@
             "vendor/devfactory/minify/src/Providers/BaseProvider.php",
             "vendor/barryvdh/laravel-debugbar/src/DataFormatter/QueryFormatter.php",
             "vendor/symfony/process/Process.php",
+            "vendor/symfony/http-kernel/UriSigner.php",
             "vendor/symfony/http-kernel/Exception/HttpException.php",
             "vendor/symfony/http-kernel/HttpCache/Store.php",
             "vendor/barryvdh/laravel-debugbar/src/JavascriptRenderer.php",

overrides/symfony/http-kernel/UriSigner.php

@@ -0,0 +1,106 @@
+<?php
+
+/*
+ * This file is part of the Symfony package.
+ *
+ * (c) Fabien Potencier <[email protected]>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Symfony\Component\HttpKernel;
+
+/**
+ * Signs URIs.
+ *
+ * @author Fabien Potencier <[email protected]>
+ */
+class UriSigner
+{
+    private $secret;
+    private $parameter;
+
+    /**
+     * @param string $secret    A secret
+     * @param string $parameter Query string parameter to use
+     */
+    public function __construct($secret, $parameter = '_hash')
+    {
+        $this->secret = $secret;
+        $this->parameter = $parameter;
+    }
+
+    /**
+     * Signs a URI.
+     *
+     * The given URI is signed by adding the query string parameter
+     * which value depends on the URI and the secret.
+     *
+     * @param string $uri A URI to sign
+     *
+     * @return string The signed URI
+     */
+    public function sign($uri)
+    {
+        $url = parse_url($uri);
+        if (isset($url['query'])) {
+            parse_str($url['query'], $params);
+        } else {
+            $params = array();
+        }
+
+        $uri = $this->buildUrl($url, $params);
+
+        return $uri.(false === strpos($uri, '?') ? '?' : '&').$this->parameter.'='.$this->computeHash($uri);
+    }
+
+    /**
+     * Checks that a URI contains the correct hash.
+     *
+     * @param string $uri A signed URI
+     *
+     * @return bool True if the URI is signed correctly, false otherwise
+     */
+    public function check($uri)
+    {
+        $url = parse_url($uri);
+        if (isset($url['query'])) {
+            parse_str($url['query'], $params);
+        } else {
+            $params = array();
+        }
+
+        if (empty($params[$this->parameter])) {
+            return false;
+        }
+
+        $hash = urlencode($params[$this->parameter]);
+        unset($params[$this->parameter]);
+
+        return hash_equals($this->computeHash($this->buildUrl($url, $params)), $hash);
+    }
+
+    private function computeHash($uri)
+    {
+        return urlencode(base64_encode(hash_hmac('sha256', $uri, $this->secret, true)));
+    }
+
+    private function buildUrl(array $url, array $params = array())
+    {
+        ksort($params, SORT_STRING);
+        $url['query'] = http_build_query($params, '', '&');
+
+        $scheme = isset($url['scheme']) ? $url['scheme'].'://' : '';
+        $host = isset($url['host']) ? $url['host'] : '';
+        $port = isset($url['port']) ? ':'.$url['port'] : '';
+        $user = isset($url['user']) ? $url['user'] : '';
+        $pass = isset($url['pass']) ? ':'.$url['pass'] : '';
+        $pass = ($user || $pass) ? "$pass@" : '';
+        $path = isset($url['path']) ? $url['path'] : '';
+        $query = isset($url['query']) && $url['query'] ? '?'.$url['query'] : '';
+        $fragment = isset($url['fragment']) ? '#'.$url['fragment'] : '';
+
+        return $scheme.$user.$pass.$host.$port.$path.$query.$fragment;
+    }
+}