| 1 |
<?php |
| 2 |
/** |
| 3 |
* MetaSync MCP Server |
| 4 |
* |
| 5 |
* Main MCP server class that implements the Model Context Protocol |
| 6 |
* for WordPress. Exposes WordPress operations as MCP tools. |
| 7 |
* |
| 8 |
* @package MetaSync |
| 9 |
* @subpackage MCP_Server |
| 10 |
*/ |
| 11 |
|
| 12 |
if (!defined('ABSPATH')) { |
| 13 |
exit; |
| 14 |
} |
| 15 |
|
| 16 |
class Metasync_MCP_Server { |
| 17 |
|
| 18 |
/** |
| 19 |
* JSON-RPC handler |
| 20 |
* |
| 21 |
* @var MCP_JSON_RPC_Handler |
| 22 |
*/ |
| 23 |
private $json_rpc_handler; |
| 24 |
|
| 25 |
/** |
| 26 |
* Tool registry |
| 27 |
* |
| 28 |
* @var MCP_Tool_Registry |
| 29 |
*/ |
| 30 |
private $tool_registry; |
| 31 |
|
| 32 |
/** |
| 33 |
* Authenticated identity for the current request |
| 34 |
* |
| 35 |
* Populated by authenticate_request() with the shape |
| 36 |
* ['type' => 'api_key'|'jwt'|'user'|'nonce', 'id' => <stable string>]. |
| 37 |
* |
| 38 |
* @var array|null |
| 39 |
*/ |
| 40 |
private $authenticated_identity = null; |
| 41 |
|
| 42 |
/** |
| 43 |
* REST namespace |
| 44 |
*/ |
| 45 |
const REST_NAMESPACE = 'metasync/v1'; |
| 46 |
|
| 47 |
/** |
| 48 |
* REST route |
| 49 |
*/ |
| 50 |
const REST_ROUTE = '/mcp'; |
| 51 |
|
| 52 |
/** |
| 53 |
* JWT token expiration time (in seconds) |
| 54 |
* Default: 24 hours |
| 55 |
*/ |
| 56 |
const JWT_EXPIRATION = 86400; |
| 57 |
|
| 58 |
/** |
| 59 |
* Default tool-call rate limit (requests per window) for authenticated MCP clients. |
| 60 |
*/ |
| 61 |
const DEFAULT_TOOL_CALL_LIMIT = 60; |
| 62 |
|
| 63 |
/** |
| 64 |
* Default tool-call rate-limit window in seconds. |
| 65 |
*/ |
| 66 |
const DEFAULT_TOOL_CALL_WINDOW = 60; |
| 67 |
|
| 68 |
/** |
| 69 |
* Constructor |
| 70 |
*/ |
| 71 |
public function __construct() { |
| 72 |
// Load dependencies |
| 73 |
$this->load_dependencies(); |
| 74 |
|
| 75 |
// Initialize components |
| 76 |
$this->json_rpc_handler = new MCP_JSON_RPC_Handler(); |
| 77 |
$this->tool_registry = MCP_Tool_Registry::get_instance(); |
| 78 |
|
| 79 |
// Register handlers |
| 80 |
$this->register_json_rpc_handlers(); |
| 81 |
|
| 82 |
// WordPress hooks |
| 83 |
add_action('rest_api_init', [$this, 'register_rest_routes']); |
| 84 |
} |
| 85 |
|
| 86 |
/** |
| 87 |
* Load dependencies |
| 88 |
*/ |
| 89 |
private function load_dependencies() { |
| 90 |
require_once plugin_dir_path(__FILE__) . 'class-mcp-json-rpc-handler.php'; |
| 91 |
require_once plugin_dir_path(__FILE__) . 'class-mcp-tool-base.php'; |
| 92 |
require_once plugin_dir_path(__FILE__) . 'class-mcp-tool-registry.php'; |
| 93 |
require_once plugin_dir_path(__FILE__) . '../includes/class-metasync-rate-limiter.php'; |
| 94 |
} |
| 95 |
|
| 96 |
/** |
| 97 |
* Register JSON-RPC method handlers |
| 98 |
*/ |
| 99 |
private function register_json_rpc_handlers() { |
| 100 |
$this->json_rpc_handler->register_handler('tools/list', [$this, 'handle_tools_list']); |
| 101 |
$this->json_rpc_handler->register_handler('tools/call', [$this, 'handle_tools_call']); |
| 102 |
} |
| 103 |
|
| 104 |
/** |
| 105 |
* Register REST routes |
| 106 |
*/ |
| 107 |
public function register_rest_routes() { |
| 108 |
register_rest_route(self::REST_NAMESPACE, self::REST_ROUTE, [ |
| 109 |
'methods' => 'POST', |
| 110 |
'callback' => [$this, 'handle_rest_request'], |
| 111 |
'permission_callback' => [$this, 'check_permissions'], |
| 112 |
]); |
| 113 |
|
| 114 |
// Health check endpoint |
| 115 |
register_rest_route(self::REST_NAMESPACE, '/mcp/health', [ |
| 116 |
'methods' => 'GET', |
| 117 |
'callback' => [$this, 'handle_health_check'], |
| 118 |
'permission_callback' => '__return_true', |
| 119 |
]); |
| 120 |
|
| 121 |
// JWT authentication endpoint |
| 122 |
register_rest_route(self::REST_NAMESPACE, '/mcp/auth', [ |
| 123 |
'methods' => 'POST', |
| 124 |
'callback' => [$this, 'handle_jwt_auth'], |
| 125 |
'permission_callback' => '__return_true', |
| 126 |
]); |
| 127 |
} |
| 128 |
|
| 129 |
/** |
| 130 |
* Handle REST request |
| 131 |
* |
| 132 |
* @param WP_REST_Request $request Request object |
| 133 |
* @return WP_REST_Response |
| 134 |
*/ |
| 135 |
public function handle_rest_request($request) { |
| 136 |
$request_body = $request->get_body(); |
| 137 |
|
| 138 |
// Only rate-limit tools/call requests, not tools/list or other methods. |
| 139 |
$decoded = json_decode($request_body, true); |
| 140 |
$is_tool_call = is_array($decoded) |
| 141 |
&& isset($decoded['method']) |
| 142 |
&& $decoded['method'] === 'tools/call'; |
| 143 |
|
| 144 |
if ($is_tool_call && $this->authenticated_identity !== null) { |
| 145 |
$default_limits = [ |
| 146 |
'max' => self::DEFAULT_TOOL_CALL_LIMIT, |
| 147 |
'window' => self::DEFAULT_TOOL_CALL_WINDOW, |
| 148 |
]; |
| 149 |
$limits = apply_filters('metasync_mcp_tool_call_rate_limit', $default_limits, $this->authenticated_identity); |
| 150 |
|
| 151 |
$max = isset($limits['max']) ? (int) $limits['max'] : self::DEFAULT_TOOL_CALL_LIMIT; |
| 152 |
$window = isset($limits['window']) ? (int) $limits['window'] : self::DEFAULT_TOOL_CALL_WINDOW; |
| 153 |
|
| 154 |
$rate_result = Metasync_Rate_Limiter::get_instance()->check_rate_limit( |
| 155 |
$this->authenticated_identity['id'], |
| 156 |
$max, |
| 157 |
$window, |
| 158 |
'mcp_tool_' |
| 159 |
); |
| 160 |
|
| 161 |
if (is_wp_error($rate_result)) { |
| 162 |
$error_data = $rate_result->get_error_data(); |
| 163 |
$retry_after = isset($error_data['retry_after']) ? (int) $error_data['retry_after'] : $window; |
| 164 |
|
| 165 |
$req_id = isset($decoded['id']) ? $decoded['id'] : null; |
| 166 |
|
| 167 |
$error_body = [ |
| 168 |
'jsonrpc' => '2.0', |
| 169 |
'id' => $req_id, |
| 170 |
'error' => [ |
| 171 |
'code' => MCP_JSON_RPC_Handler::ERROR_RATE_LIMITED, |
| 172 |
'message' => 'Rate limit exceeded', |
| 173 |
'data' => [ |
| 174 |
'retry_after' => $retry_after, |
| 175 |
], |
| 176 |
], |
| 177 |
]; |
| 178 |
|
| 179 |
$response = new WP_REST_Response($error_body, 429); |
| 180 |
$response->header('Retry-After', (string) $retry_after); |
| 181 |
return $response; |
| 182 |
} |
| 183 |
} |
| 184 |
|
| 185 |
// Process through JSON-RPC handler |
| 186 |
$response = $this->json_rpc_handler->handle_request($request_body); |
| 187 |
|
| 188 |
return new WP_REST_Response($response, 200); |
| 189 |
} |
| 190 |
|
| 191 |
/** |
| 192 |
* Handle health check |
| 193 |
* |
| 194 |
* @return WP_REST_Response |
| 195 |
*/ |
| 196 |
public function handle_health_check() { |
| 197 |
return new WP_REST_Response([ |
| 198 |
'status' => 'ok', |
| 199 |
'version' => METASYNC_VERSION, |
| 200 |
'tools_count' => $this->tool_registry->get_tool_count(), |
| 201 |
'enabled' => true |
| 202 |
], 200); |
| 203 |
} |
| 204 |
|
| 205 |
/** |
| 206 |
* Check permissions |
| 207 |
* |
| 208 |
* @param WP_REST_Request $request Request object |
| 209 |
* @return bool|WP_Error |
| 210 |
*/ |
| 211 |
public function check_permissions($request) { |
| 212 |
// Check authentication |
| 213 |
$auth_result = $this->authenticate_request($request); |
| 214 |
if (is_wp_error($auth_result)) { |
| 215 |
return $auth_result; |
| 216 |
} |
| 217 |
|
| 218 |
// If authenticated via API key, skip capability check |
| 219 |
// API key already proves admin-level access |
| 220 |
$api_key = $request->get_header('X-API-Key'); |
| 221 |
if ($api_key && $this->verify_plugin_auth_token($api_key)) { |
| 222 |
if (!defined('METASYNC_MCP_API_KEY_AUTH')) { |
| 223 |
define('METASYNC_MCP_API_KEY_AUTH', true); |
| 224 |
} |
| 225 |
return true; |
| 226 |
} |
| 227 |
|
| 228 |
// If authenticated via JWT, check if it's API key-based or user-based |
| 229 |
if (defined('METASYNC_MCP_JWT_AUTH') && METASYNC_MCP_JWT_AUTH) { |
| 230 |
// If JWT was generated from API key (user_id = 0), skip capability check |
| 231 |
// API key-based JWT tokens have full system-level access |
| 232 |
if (defined('METASYNC_MCP_API_KEY_AUTH') && METASYNC_MCP_API_KEY_AUTH) { |
| 233 |
return true; |
| 234 |
} |
| 235 |
|
| 236 |
// For user-based JWT tokens, check user capability |
| 237 |
if (!current_user_can('manage_options')) { |
| 238 |
return new WP_Error( |
| 239 |
'insufficient_permissions', |
| 240 |
'User does not have permission to use the MCP server', |
| 241 |
['status' => 403] |
| 242 |
); |
| 243 |
} |
| 244 |
return true; |
| 245 |
} |
| 246 |
|
| 247 |
// For nonce-based auth, check user capability |
| 248 |
if (!current_user_can('manage_options')) { |
| 249 |
return new WP_Error( |
| 250 |
'insufficient_permissions', |
| 251 |
'You do not have permission to use the MCP server', |
| 252 |
['status' => 403] |
| 253 |
); |
| 254 |
} |
| 255 |
|
| 256 |
return true; |
| 257 |
} |
| 258 |
|
| 259 |
/** |
| 260 |
* Authenticate request |
| 261 |
* |
| 262 |
* Supports three authentication methods: |
| 263 |
* 1. WordPress nonce (same-origin) |
| 264 |
* 2. Plugin auth token (external clients) |
| 265 |
* 3. JWT Bearer token (industry-standard) |
| 266 |
* |
| 267 |
* @param WP_REST_Request $request Request object |
| 268 |
* @return bool|WP_Error |
| 269 |
*/ |
| 270 |
private function authenticate_request($request) { |
| 271 |
// Method 1: WordPress nonce (for same-origin requests) |
| 272 |
$nonce = $request->get_header('X-WP-Nonce'); |
| 273 |
if ($nonce && wp_verify_nonce($nonce, 'wp_rest')) { |
| 274 |
$this->authenticated_identity = [ |
| 275 |
'type' => 'user', |
| 276 |
'id' => 'user:' . get_current_user_id(), |
| 277 |
]; |
| 278 |
return true; |
| 279 |
} |
| 280 |
|
| 281 |
// Method 2: Plugin auth token (for external clients like Claude Desktop) |
| 282 |
$api_key = $request->get_header('X-API-Key'); |
| 283 |
if ($api_key && $this->verify_plugin_auth_token($api_key)) { |
| 284 |
$this->authenticated_identity = [ |
| 285 |
'type' => 'api_key', |
| 286 |
'id' => hash('sha256', $api_key), |
| 287 |
]; |
| 288 |
return true; |
| 289 |
} |
| 290 |
|
| 291 |
// Method 3: JWT Bearer token (industry-standard authentication) |
| 292 |
$auth_header = $request->get_header('Authorization'); |
| 293 |
if ($auth_header && preg_match('/Bearer\s+(.+)/i', $auth_header, $matches)) { |
| 294 |
$jwt_token = trim($matches[1]); |
| 295 |
$jwt_result = $this->verify_jwt_token($jwt_token); |
| 296 |
if ($jwt_result !== false) { |
| 297 |
// If user_id is 0, this is an API key-based JWT token (system-level access) |
| 298 |
// Treat it like API key authentication (no user context needed) |
| 299 |
if ($jwt_result['user_id'] === 0) { |
| 300 |
if (!defined('METASYNC_MCP_JWT_AUTH')) { |
| 301 |
define('METASYNC_MCP_JWT_AUTH', true); |
| 302 |
} |
| 303 |
if (!defined('METASYNC_MCP_API_KEY_AUTH')) { |
| 304 |
define('METASYNC_MCP_API_KEY_AUTH', true); |
| 305 |
} |
| 306 |
$this->authenticated_identity = [ |
| 307 |
'type' => 'api_key', |
| 308 |
'id' => $jwt_result['sub'], |
| 309 |
]; |
| 310 |
} else { |
| 311 |
// Set the authenticated user from JWT |
| 312 |
wp_set_current_user($jwt_result['user_id']); |
| 313 |
if (!defined('METASYNC_MCP_JWT_AUTH')) { |
| 314 |
define('METASYNC_MCP_JWT_AUTH', true); |
| 315 |
} |
| 316 |
$this->authenticated_identity = [ |
| 317 |
'type' => 'user', |
| 318 |
'id' => $jwt_result['sub'], |
| 319 |
]; |
| 320 |
} |
| 321 |
return true; |
| 322 |
} |
| 323 |
} |
| 324 |
|
| 325 |
return new WP_Error( |
| 326 |
'authentication_failed', |
| 327 |
'Authentication required. Provide X-WP-Nonce, X-API-Key, or Authorization: Bearer <jwt_token> header.', |
| 328 |
['status' => 401] |
| 329 |
); |
| 330 |
} |
| 331 |
|
| 332 |
/** |
| 333 |
* Verify plugin auth token |
| 334 |
* |
| 335 |
* @param string $provided_token Provided auth token |
| 336 |
* @return bool |
| 337 |
*/ |
| 338 |
private function verify_plugin_auth_token($provided_token) { |
| 339 |
$options = get_option('metasync_options', []); |
| 340 |
$stored_token = isset($options['general']['apikey']) ? $options['general']['apikey'] : null; |
| 341 |
|
| 342 |
if (empty($stored_token)) { |
| 343 |
return false; |
| 344 |
} |
| 345 |
|
| 346 |
return hash_equals($stored_token, $provided_token); |
| 347 |
} |
| 348 |
|
| 349 |
/** |
| 350 |
* Handle tools/list method |
| 351 |
* |
| 352 |
* @param array $params Request parameters |
| 353 |
* @return array |
| 354 |
*/ |
| 355 |
public function handle_tools_list($params) { |
| 356 |
$tools = $this->tool_registry->get_tools_list(); |
| 357 |
|
| 358 |
return [ |
| 359 |
'tools' => $tools |
| 360 |
]; |
| 361 |
} |
| 362 |
|
| 363 |
/** |
| 364 |
* Handle tools/call method |
| 365 |
* |
| 366 |
* @param array $params Request parameters |
| 367 |
* @return array |
| 368 |
* @throws InvalidArgumentException If parameters are invalid |
| 369 |
*/ |
| 370 |
public function handle_tools_call($params) { |
| 371 |
// Validate params |
| 372 |
if (!isset($params['name'])) { |
| 373 |
throw new InvalidArgumentException('Missing required parameter: name'); |
| 374 |
} |
| 375 |
|
| 376 |
$tool_name = $params['name']; |
| 377 |
$tool_params = isset($params['arguments']) ? $params['arguments'] : []; |
| 378 |
|
| 379 |
// Execute tool |
| 380 |
try { |
| 381 |
$result = $this->tool_registry->execute_tool($tool_name, $tool_params); |
| 382 |
|
| 383 |
return [ |
| 384 |
'content' => [ |
| 385 |
[ |
| 386 |
'type' => 'text', |
| 387 |
'text' => json_encode($result, JSON_PRETTY_PRINT) |
| 388 |
] |
| 389 |
] |
| 390 |
]; |
| 391 |
} catch (InvalidArgumentException $e) { |
| 392 |
throw $e; |
| 393 |
} catch (Exception $e) { |
| 394 |
throw new Exception('Tool execution failed: ' . $e->getMessage()); |
| 395 |
} |
| 396 |
} |
| 397 |
|
| 398 |
/** |
| 399 |
* Register a tool |
| 400 |
* |
| 401 |
* @param MCP_Tool_Base $tool Tool instance |
| 402 |
* @return bool |
| 403 |
*/ |
| 404 |
public function register_tool(MCP_Tool_Base $tool) { |
| 405 |
return $this->tool_registry->register_tool($tool); |
| 406 |
} |
| 407 |
|
| 408 |
/** |
| 409 |
* Get tool registry instance |
| 410 |
* Allows internal components (like OTTO integration) to call MCP tools directly |
| 411 |
* |
| 412 |
* @return MCP_Tool_Registry |
| 413 |
*/ |
| 414 |
public function get_tool_registry() { |
| 415 |
return $this->tool_registry; |
| 416 |
} |
| 417 |
|
| 418 |
/** |
| 419 |
* Get plugin auth token |
| 420 |
* |
| 421 |
* @return string|false |
| 422 |
*/ |
| 423 |
public function get_api_key() { |
| 424 |
$options = get_option('metasync_options', []); |
| 425 |
return isset($options['general']['apikey']) ? $options['general']['apikey'] : false; |
| 426 |
} |
| 427 |
|
| 428 |
/** |
| 429 |
* Get server info |
| 430 |
* |
| 431 |
* @return array |
| 432 |
*/ |
| 433 |
public function get_server_info() { |
| 434 |
return [ |
| 435 |
'enabled' => true, |
| 436 |
'endpoint' => rest_url(self::REST_NAMESPACE . self::REST_ROUTE), |
| 437 |
'tools_count' => $this->tool_registry->get_tool_count(), |
| 438 |
'version' => METASYNC_VERSION, |
| 439 |
'has_auth_token' => !empty($this->get_api_key()) |
| 440 |
]; |
| 441 |
} |
| 442 |
|
| 443 |
/** |
| 444 |
* Handle JWT authentication request |
| 445 |
* Generates a JWT token by exchanging plugin API key for time-limited JWT |
| 446 |
* |
| 447 |
* @param WP_REST_Request $request Request object |
| 448 |
* @return WP_REST_Response|WP_Error |
| 449 |
*/ |
| 450 |
public function handle_jwt_auth($request) { |
| 451 |
$ip = isset($_SERVER['REMOTE_ADDR']) ? $_SERVER['REMOTE_ADDR'] : '0.0.0.0'; |
| 452 |
|
| 453 |
// Enforce brute-force rate limit before any further processing |
| 454 |
$rate_limit_result = $this->check_rate_limit($ip); |
| 455 |
if (is_wp_error($rate_limit_result)) { |
| 456 |
return $rate_limit_result; |
| 457 |
} |
| 458 |
|
| 459 |
$params = $request->get_json_params(); |
| 460 |
|
| 461 |
// Get API key from request body or header |
| 462 |
$api_key = ''; |
| 463 |
if (isset($params['api_key'])) { |
| 464 |
$api_key = sanitize_text_field($params['api_key']); |
| 465 |
} else { |
| 466 |
$api_key = $request->get_header('X-API-Key'); |
| 467 |
} |
| 468 |
|
| 469 |
if (empty($api_key)) { |
| 470 |
$this->record_failed_auth_attempt($ip); |
| 471 |
return new WP_Error( |
| 472 |
'missing_api_key', |
| 473 |
'API key is required. Provide in request body as "api_key" or in X-API-Key header.', |
| 474 |
['status' => 400] |
| 475 |
); |
| 476 |
} |
| 477 |
|
| 478 |
// Verify API key |
| 479 |
if (!$this->verify_plugin_auth_token($api_key)) { |
| 480 |
$this->record_failed_auth_attempt($ip); |
| 481 |
return new WP_Error( |
| 482 |
'invalid_api_key', |
| 483 |
'Invalid API key', |
| 484 |
['status' => 401] |
| 485 |
); |
| 486 |
} |
| 487 |
|
| 488 |
// Successful authentication — clear any accumulated failure counters |
| 489 |
$this->clear_auth_attempts($ip); |
| 490 |
|
| 491 |
// Generate JWT token |
| 492 |
// Use 0 as user_id to indicate API key authentication (system-level access) |
| 493 |
$token = $this->generate_jwt_token(0); |
| 494 |
|
| 495 |
if ($token === false) { |
| 496 |
return new WP_Error( |
| 497 |
'token_generation_failed', |
| 498 |
'Failed to generate JWT token', |
| 499 |
['status' => 500] |
| 500 |
); |
| 501 |
} |
| 502 |
|
| 503 |
return new WP_REST_Response([ |
| 504 |
'success' => true, |
| 505 |
'token' => $token, |
| 506 |
'token_type' => 'Bearer', |
| 507 |
'expires_in' => self::JWT_EXPIRATION, |
| 508 |
'expires_at' => time() + self::JWT_EXPIRATION, |
| 509 |
'scope' => 'mcp:full_access' |
| 510 |
], 200); |
| 511 |
} |
| 512 |
|
| 513 |
/** |
| 514 |
* Generate JWT token |
| 515 |
* |
| 516 |
* @param int $user_id WordPress user ID (0 for API key based tokens) |
| 517 |
* @return string|false JWT token or false on failure |
| 518 |
*/ |
| 519 |
private function generate_jwt_token($user_id) { |
| 520 |
$issued_at = time(); |
| 521 |
$expiration = $issued_at + self::JWT_EXPIRATION; |
| 522 |
|
| 523 |
// JWT header |
| 524 |
$header = [ |
| 525 |
'alg' => 'HS256', |
| 526 |
'typ' => 'JWT' |
| 527 |
]; |
| 528 |
|
| 529 |
// JWT payload |
| 530 |
// user_id = 0 indicates API key authentication (system-level access) |
| 531 |
$payload = [ |
| 532 |
'sub' => $user_id === 0 ? 'api_key' : 'user:' . $user_id, |
| 533 |
'user_id' => $user_id, |
| 534 |
'iat' => $issued_at, |
| 535 |
'exp' => $expiration, |
| 536 |
'iss' => get_site_url(), |
| 537 |
'scope' => 'mcp:full_access' |
| 538 |
]; |
| 539 |
|
| 540 |
// Encode header and payload |
| 541 |
$header_encoded = $this->base64_url_encode(json_encode($header)); |
| 542 |
$payload_encoded = $this->base64_url_encode(json_encode($payload)); |
| 543 |
|
| 544 |
// Create signature |
| 545 |
$signature_input = $header_encoded . '.' . $payload_encoded; |
| 546 |
$secret = $this->get_jwt_secret(); |
| 547 |
$signature = hash_hmac('sha256', $signature_input, $secret, true); |
| 548 |
$signature_encoded = $this->base64_url_encode($signature); |
| 549 |
|
| 550 |
// Create JWT token |
| 551 |
$jwt = $header_encoded . '.' . $payload_encoded . '.' . $signature_encoded; |
| 552 |
|
| 553 |
return $jwt; |
| 554 |
} |
| 555 |
|
| 556 |
/** |
| 557 |
* Verify JWT token |
| 558 |
* |
| 559 |
* @param string $token JWT token |
| 560 |
* @return array|false Decoded payload or false on failure |
| 561 |
*/ |
| 562 |
private function verify_jwt_token($token) { |
| 563 |
// Split token into parts |
| 564 |
$parts = explode('.', $token); |
| 565 |
|
| 566 |
if (count($parts) !== 3) { |
| 567 |
return false; |
| 568 |
} |
| 569 |
|
| 570 |
list($header_encoded, $payload_encoded, $signature_encoded) = $parts; |
| 571 |
|
| 572 |
// Validate header: enforce alg=HS256 and typ=JWT to defeat |
| 573 |
// algorithm-confusion attacks (e.g. "alg":"none"). |
| 574 |
$header_json = $this->base64_url_decode($header_encoded); |
| 575 |
$header = json_decode($header_json, true); |
| 576 |
if (!is_array($header)) { |
| 577 |
return false; |
| 578 |
} |
| 579 |
if (!isset($header['alg']) || $header['alg'] !== 'HS256') { |
| 580 |
return false; |
| 581 |
} |
| 582 |
if (!isset($header['typ']) || $header['typ'] !== 'JWT') { |
| 583 |
return false; |
| 584 |
} |
| 585 |
|
| 586 |
// Verify signature |
| 587 |
$signature_input = $header_encoded . '.' . $payload_encoded; |
| 588 |
$secret = $this->get_jwt_secret(); |
| 589 |
$signature = hash_hmac('sha256', $signature_input, $secret, true); |
| 590 |
$signature_expected = $this->base64_url_encode($signature); |
| 591 |
|
| 592 |
if (!hash_equals($signature_expected, $signature_encoded)) { |
| 593 |
return false; |
| 594 |
} |
| 595 |
|
| 596 |
// Decode payload |
| 597 |
$payload_json = $this->base64_url_decode($payload_encoded); |
| 598 |
$payload = json_decode($payload_json, true); |
| 599 |
|
| 600 |
if (!$payload) { |
| 601 |
return false; |
| 602 |
} |
| 603 |
|
| 604 |
// Check expiration — exp is mandatory; reject tokens missing or |
| 605 |
// with a non-numeric / past expiry. |
| 606 |
if (!isset($payload['exp']) || !is_numeric($payload['exp']) || (int) $payload['exp'] < time()) { |
| 607 |
return false; |
| 608 |
} |
| 609 |
|
| 610 |
// Check issuer — iss is mandatory and must match this site. |
| 611 |
if (!isset($payload['iss']) || $payload['iss'] !== get_site_url()) { |
| 612 |
return false; |
| 613 |
} |
| 614 |
|
| 615 |
// Check user_id exists |
| 616 |
if (!isset($payload['user_id'])) { |
| 617 |
return false; |
| 618 |
} |
| 619 |
|
| 620 |
// If user_id is 0, this is an API key-based token (system-level access) |
| 621 |
// No need to validate user existence |
| 622 |
if ($payload['user_id'] === 0) { |
| 623 |
return $payload; |
| 624 |
} |
| 625 |
|
| 626 |
// For user-based tokens, verify user exists |
| 627 |
$user = get_user_by('id', $payload['user_id']); |
| 628 |
if (!$user) { |
| 629 |
return false; |
| 630 |
} |
| 631 |
|
| 632 |
return $payload; |
| 633 |
} |
| 634 |
|
| 635 |
/** |
| 636 |
* Get JWT secret key |
| 637 |
* |
| 638 |
* Uses a dedicated random secret stored in the WordPress options table. |
| 639 |
* A new secret is generated on first use and persisted so that existing |
| 640 |
* tokens remain valid across requests. |
| 641 |
* |
| 642 |
* @return string |
| 643 |
*/ |
| 644 |
private function get_jwt_secret() { |
| 645 |
$secret = get_option('metasync_jwt_secret'); |
| 646 |
if (empty($secret)) { |
| 647 |
$secret = wp_generate_password(64, true, true); |
| 648 |
update_option('metasync_jwt_secret', $secret, false); |
| 649 |
} |
| 650 |
return $secret; |
| 651 |
} |
| 652 |
|
| 653 |
/** |
| 654 |
* Check whether the given IP has exceeded the authentication rate limit. |
| 655 |
* |
| 656 |
* Allows up to 10 failed attempts within any 15-minute window. Returns a |
| 657 |
* WP_Error with HTTP 429 if the limit is exceeded, or true otherwise. |
| 658 |
* |
| 659 |
* @param string $ip Client IP address |
| 660 |
* @return true|WP_Error |
| 661 |
*/ |
| 662 |
private function check_rate_limit($ip) { |
| 663 |
$key = 'metasync_auth_attempts_' . md5($ip); |
| 664 |
$attempts = (int) get_transient($key); |
| 665 |
if ($attempts >= 10) { |
| 666 |
return new WP_Error( |
| 667 |
'too_many_requests', |
| 668 |
'Too many failed authentication attempts. Try again later.', |
| 669 |
['status' => 429] |
| 670 |
); |
| 671 |
} |
| 672 |
return true; |
| 673 |
} |
| 674 |
|
| 675 |
/** |
| 676 |
* Increment the failed-authentication counter for the given IP. |
| 677 |
* |
| 678 |
* The counter expires automatically after 15 minutes. |
| 679 |
* |
| 680 |
* @param string $ip Client IP address |
| 681 |
* @return void |
| 682 |
*/ |
| 683 |
private function record_failed_auth_attempt($ip) { |
| 684 |
global $wpdb; |
| 685 |
$key = 'metasync_auth_attempts_' . md5($ip); |
| 686 |
$window = 15 * MINUTE_IN_SECONDS; |
| 687 |
|
| 688 |
// Use get_transient to check existence first |
| 689 |
$attempts = get_transient($key); |
| 690 |
if ($attempts === false) { |
| 691 |
// First attempt: set initial value atomically |
| 692 |
set_transient($key, 1, $window); |
| 693 |
} else { |
| 694 |
// Increment atomically via direct SQL to avoid race conditions |
| 695 |
$option_name = '_transient_' . $key; |
| 696 |
$updated = $wpdb->query( |
| 697 |
$wpdb->prepare( |
| 698 |
"UPDATE {$wpdb->options} SET option_value = option_value + 1 WHERE option_name = %s", |
| 699 |
$option_name |
| 700 |
) |
| 701 |
); |
| 702 |
// If no rows updated (e.g. object cache backend), fall back to set |
| 703 |
if ($updated === 0) { |
| 704 |
set_transient($key, (int) $attempts + 1, $window); |
| 705 |
} |
| 706 |
} |
| 707 |
} |
| 708 |
|
| 709 |
/** |
| 710 |
* Clear the failed-authentication counter for the given IP. |
| 711 |
* |
| 712 |
* Called on successful authentication to reset brute-force tracking. |
| 713 |
* |
| 714 |
* @param string $ip Client IP address |
| 715 |
* @return void |
| 716 |
*/ |
| 717 |
private function clear_auth_attempts($ip) { |
| 718 |
$key = 'metasync_auth_attempts_' . md5($ip); |
| 719 |
delete_transient($key); |
| 720 |
} |
| 721 |
|
| 722 |
/** |
| 723 |
* Base64 URL encode |
| 724 |
* |
| 725 |
* @param string $data Data to encode |
| 726 |
* @return string |
| 727 |
*/ |
| 728 |
private function base64_url_encode($data) { |
| 729 |
return rtrim(strtr(base64_encode($data), '+/', '-_'), '='); |
| 730 |
} |
| 731 |
|
| 732 |
/** |
| 733 |
* Base64 URL decode |
| 734 |
* |
| 735 |
* @param string $data Data to decode |
| 736 |
* @return string |
| 737 |
*/ |
| 738 |
private function base64_url_decode($data) { |
| 739 |
return base64_decode(strtr($data, '-_', '+/')); |
| 740 |
} |
| 741 |
} |
| 742 |
|
