Added MAC TokenType

src/TokenType/MAC.php

@@ -0,0 +1,141 @@
+<?php
+/**
+ * OAuth 2.0 MAC Token Type
+ *
+ * @package     league/oauth2-server
+ * @author      Alex Bilbie <hello@alexbilbie.com>
+ * @copyright   Copyright (c) Alex Bilbie
+ * @license     http://mit-license.org/
+ * @link        https://github.com/thephpleague/oauth2-server
+ */
+
+namespace League\OAuth2\Server\TokenType;
+
+use League\OAuth2\Server\Util\SecureKey;
+use Symfony\Component\HttpFoundation\ParameterBag;
+use Symfony\Component\HttpFoundation\Request;
+
+/**
+ * MAC Token Type
+ */
+class MAC extends AbstractTokenType implements TokenTypeInterface
+{
+    /**
+     * {@inheritdoc}
+     */
+    public function generateResponse()
+    {
+        $macKey = SecureKey::generate();
+        $this->server->getMacStorage()->create($macKey, $this->getParam('access_token'));
+
+        $response = [
+            'access_token'  =>  $this->getParam('access_token'),
+            'token_type'    =>  'mac',
+            'expires_in'    =>  $this->getParam('expires_in'),
+            'mac_key'       =>  $macKey,
+            'mac_algorithm' =>  'hmac-sha-256',
+        ];
+
+        return $response;
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function determineAccessTokenInHeader(Request $request)
+    {
+        if ($request->headers->has('Authorization') === false) {
+            return;
+        }
+
+        $header = $request->headers->get('Authorization');
+
+        if (substr($header, 0, 4) !== 'MAC ') {
+            return;
+        }
+
+        // Find all the parameters expressed in the header
+        $paramsRaw = explode(',', substr($header, 4));
+        $params = new ParameterBag();
+
+        array_map(function ($param) use (&$params) {
+            $param = trim($param);
+
+            preg_match_all('/([a-zA-Z]*)="([\w=]*)"/', $param, $matches);
+
+            if (count($matches) !== 3) {
+                return;
+            }
+
+            $key = reset($matches[1]);
+            $value = trim(reset($matches[2]));
+
+            if (empty($value)) {
+                return;
+            }
+
+            $params->add($key, $value);
+        }, $paramsRaw);
+
+        // Validate parameters
+        if ($params->has('id') === false || $params->has('ts') === false || $params->has('nonce') === false || $params->has('mac') === false) {
+            return;
+        }
+
+        if ((int) $params->get('ts') !== time()) {
+            return;
+        }
+
+        $accessToken = $params->get('id');
+        $timestamp = (int) $params->get('ts');
+        $nonce = $params->get('nonce');
+        $signature = $params->get('mac');
+
+        // Try to find the MAC key for the access token
+        $macKey = $this->server->getMacStorage()->getByAccessToken($accessToken);
+
+        if ($macKey === null) {
+            return;
+        }
+
+        // Calculate and compare the signature
+        $calculatedSignatureParts = [
+            $timestamp,
+            $nonce,
+            strtoupper($request->getMethod()),
+            $request->getUri(),
+            $request->getHost(),
+            $request->getPort(),
+        ];
+
+        if ($params->has('ext')) {
+            $calculatedSignatureParts[] = $params->get('ext');
+        }
+
+        $calculatedSignature = base64_encode(hash_hmac('sha256', implode("\n", $calculatedSignatureParts), $macKey)));
+
+        // Return the access token if the signature matches
+        return ($this->hash_equals($calculatedSignature, $signature)) ? $accessToken : null;
+    }
+
+    private function hash_equals($knownString, $userString)
+    {
+        if (!function_exists('hash_equals')) {
+            function hash_equals($knownString, $userString)
+            {
+                if (strlen($knownString) !== strlen($userString)) {
+                    return false;
+                }
+                $len = strlen($knownString);
+                $result = 0;
+                for ($i = 0; $i < $len; $i++) {
+                    $result |= (ord($knownString[$i]) ^ ord($userString[$i]));
+                }
+                // They are only identical strings if $result is exactly 0...
+                return 0 === $result;
+            }
+        }
+
+        return hash_equals($knownString, $userString);
+    }
+}