| 1 |
<?php |
| 2 |
/** |
| 3 |
* MCP OAuth 2.1 authorization server — the "paste a URL only" connect path. |
| 4 |
* |
| 5 |
* The pairing token (Mcp_Pairing) covers clients that accept a pasted Bearer |
| 6 |
* token; this class covers spec-compliant MCP clients (e.g. the claude.ai |
| 7 |
* remote-connector flow) that take only the server URL and run the OAuth 2.1 |
| 8 |
* authorization-code + PKCE flow themselves. |
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* |
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* Flow: unauthenticated MCP call → 401 + WWW-Authenticate (Mcp_Server) → |
| 11 |
* client fetches /.well-known/oauth-protected-resource + oauth-authorization- |
| 12 |
* server → dynamic registration (RFC 7591) → /authorize (admin consent + |
| 13 |
* PKCE) → /token (code + verifier → access + refresh) → MCP calls with |
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* `Authorization: Bearer <access>` validated by validate_token(). |
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* |
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* Security contract: |
| 17 |
* - PKCE S256 REQUIRED (OAuth 2.1 public clients); codes are single-use, |
| 18 |
* 60 s TTL, bound to client_id + redirect_uri + challenge. |
| 19 |
* - /authorize gates on manage_options — only an admin can grant access. |
| 20 |
* - Access/refresh tokens stored only as SHA-256 hashes; the raw value |
| 21 |
* exists solely in the /token response. Constant-time comparison. |
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* - Tokens carry the read/write scope model; a read-only grant refuses |
| 23 |
* every write tool, exactly like a read-only pairing token. |
| 24 |
* |
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* State lives in the `thinkrank_mcp_oauth` option (clients, codes, tokens, |
| 26 |
* refresh — keyed by id or sha256 of the secret); expired entries are pruned |
| 27 |
* lazily on every read. |
| 28 |
* |
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* @package ThinkRank\Mcp |
| 30 |
*/ |
| 31 |
|
| 32 |
declare(strict_types=1); |
| 33 |
|
| 34 |
namespace ThinkRank\Mcp; |
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|
| 36 |
if ( ! defined( 'ABSPATH' ) ) { |
| 37 |
exit; // Exit if accessed directly. |
| 38 |
} |
| 39 |
|
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/** |
| 41 |
* Minimal OAuth 2.1 authorization server for the ThinkRank MCP endpoint. |
| 42 |
*/ |
| 43 |
final class Mcp_OAuth { |
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|
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/** |
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* Option key holding all OAuth server state. |
| 47 |
*/ |
| 48 |
public const OPTION = 'thinkrank_mcp_oauth'; |
| 49 |
|
| 50 |
/** |
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* Authorization-code lifetime (seconds). Deliberately short. |
| 52 |
*/ |
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private const CODE_TTL = 60; |
| 54 |
|
| 55 |
/** |
| 56 |
* Access-token lifetime (seconds) — 1 hour, refreshable. |
| 57 |
*/ |
| 58 |
private const ACCESS_TTL = 3600; |
| 59 |
|
| 60 |
/** |
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* Refresh-token lifetime (seconds) — 30 days. |
| 62 |
*/ |
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private const REFRESH_TTL = 2592000; |
| 64 |
|
| 65 |
/** |
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* Scopes we advertise + honor. `mcp` is the umbrella scope MCP clients request. |
| 67 |
*/ |
| 68 |
private const SUPPORTED_SCOPES = [ 'mcp', 'read', 'write' ]; |
| 69 |
|
| 70 |
/** |
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* Throttle window (seconds) for per-client last-used writes — at most one |
| 72 |
* option write per minute per client, so a busy connector can't turn every |
| 73 |
* MCP call into a database write. |
| 74 |
*/ |
| 75 |
private const LAST_USED_THROTTLE = 60; |
| 76 |
|
| 77 |
/** |
| 78 |
* How many registered clients to keep. RFC 7591 registration is open by |
| 79 |
* necessity — a client must register BEFORE it can hold any credential — |
| 80 |
* so without a cap anyone on the internet can grow this option without |
| 81 |
* bound, and every state() read pays for it. Clients holding a live token |
| 82 |
* are never evicted, so the cap only ever discards abandoned registrations. |
| 83 |
*/ |
| 84 |
private const MAX_CLIENTS = 50; |
| 85 |
|
| 86 |
/** |
| 87 |
* How long an unused client registration survives (seconds). A client that |
| 88 |
* registers and never completes the flow is abandoned; real ones exchange |
| 89 |
* a code within a minute. |
| 90 |
*/ |
| 91 |
private const CLIENT_TTL = 86400; // 24 hours. |
| 92 |
|
| 93 |
// -- URLs ------------------------------------------------------------ |
| 94 |
|
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/** |
| 96 |
* The OAuth issuer identifier. Path-based (RFC 8414 §2 allows an issuer |
| 97 |
* with a path component): using the MCP endpoint URL itself means clients |
| 98 |
* derive the path-suffixed well-known URLs |
| 99 |
* (/.well-known/oauth-authorization-server/thinkrank/mcp), which stay |
| 100 |
* specific to ThinkRank even when another plugin runs its own MCP OAuth |
| 101 |
* server at the same site root. |
| 102 |
* |
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* @return string |
| 104 |
*/ |
| 105 |
public static function issuer(): string { |
| 106 |
return untrailingslashit( home_url( '/thinkrank/mcp' ) ); |
| 107 |
} |
| 108 |
|
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/** |
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* The protected resource identifier — the MCP endpoint URL. |
| 111 |
* |
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* @return string |
| 113 |
*/ |
| 114 |
public static function resource(): string { |
| 115 |
return Mcp_Pairing::site_endpoint(); |
| 116 |
} |
| 117 |
|
| 118 |
/** |
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* The browser-facing authorize page. Served OUTSIDE the REST API (via a |
| 120 |
* rewrite rule) so standard cookie auth works after the wp-login |
| 121 |
* round-trip — a REST route would see the cookie without a nonce and |
| 122 |
* treat the admin as logged-out, looping back to login. |
| 123 |
* |
| 124 |
* @return string |
| 125 |
*/ |
| 126 |
public static function authorize_url(): string { |
| 127 |
return home_url( '/thinkrank/authorize' ); |
| 128 |
} |
| 129 |
|
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/** |
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* The token endpoint URL. |
| 132 |
* |
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* @return string |
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*/ |
| 135 |
public static function token_url(): string { |
| 136 |
return rest_url( 'thinkrank/v1/mcp/oauth/token' ); |
| 137 |
} |
| 138 |
|
| 139 |
/** |
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* The dynamic client registration endpoint URL. |
| 141 |
* |
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* @return string |
| 143 |
*/ |
| 144 |
public static function register_url(): string { |
| 145 |
return rest_url( 'thinkrank/v1/mcp/oauth/register' ); |
| 146 |
} |
| 147 |
|
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/** |
| 149 |
* The protected-resource metadata URL the 401 challenge advertises. |
| 150 |
* |
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* REST-served, NOT the RFC 9728 path-insert form. The path-insert URL |
| 152 |
* lives under the site root's /.well-known/ directory, and some hosts |
| 153 |
* (SiteGround shared hosting confirmed, see #374) resolve that directory |
| 154 |
* at their Nginx edge as physical files — the request 404s before |
| 155 |
* WordPress runs, and the connecting client reports "server does not |
| 156 |
* implement OAuth" on its very first fetch. The challenge parameter is an |
| 157 |
* explicit pointer (that is what it exists for), so pointing it at a |
| 158 |
* /wp-json/ URL is spec-clean and reaches WordPress on every host and |
| 159 |
* permalink structure. The well-known variants stay served for clients |
| 160 |
* that ignore the pointer and derive the URL themselves. |
| 161 |
* |
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* @return string |
| 163 |
*/ |
| 164 |
public static function resource_metadata_url(): string { |
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/** |
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* Filter the resource_metadata URL advertised in the WWW-Authenticate |
| 167 |
* challenge, for hosts where neither the REST route nor the |
| 168 |
* /.well-known/ forms are reachable and the metadata must be served |
| 169 |
* from somewhere custom (a CDN, a static file, another domain). |
| 170 |
* |
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* @since 1.32.0 |
| 172 |
* |
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* @param string $url The advertised protected-resource metadata URL. |
| 174 |
*/ |
| 175 |
return apply_filters( |
| 176 |
'thinkrank_mcp_resource_metadata_url', |
| 177 |
rest_url( 'thinkrank/v1/mcp/oauth/protected-resource' ) |
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); |
| 179 |
} |
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|
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// -- Discovery documents (RFC 8414 / RFC 9728) ----------------------- |
| 182 |
|
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/** |
| 184 |
* RFC 9728 protected-resource metadata — tells the client which |
| 185 |
* authorization server(s) protect the MCP endpoint (this site). |
| 186 |
* |
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* @return array<string,mixed> |
| 188 |
*/ |
| 189 |
public static function protected_resource_metadata(): array { |
| 190 |
return [ |
| 191 |
'resource' => self::resource(), |
| 192 |
'authorization_servers' => [ self::issuer() ], |
| 193 |
'scopes_supported' => self::SUPPORTED_SCOPES, |
| 194 |
'bearer_methods_supported' => [ 'header' ], |
| 195 |
]; |
| 196 |
} |
| 197 |
|
| 198 |
/** |
| 199 |
* RFC 8414 authorization-server metadata — the endpoint map + the |
| 200 |
* capabilities we actually implement. |
| 201 |
* |
| 202 |
* @return array<string,mixed> |
| 203 |
*/ |
| 204 |
public static function authorization_server_metadata(): array { |
| 205 |
return [ |
| 206 |
'issuer' => self::issuer(), |
| 207 |
'authorization_endpoint' => self::authorize_url(), |
| 208 |
'token_endpoint' => self::token_url(), |
| 209 |
'registration_endpoint' => self::register_url(), |
| 210 |
'scopes_supported' => self::SUPPORTED_SCOPES, |
| 211 |
'response_types_supported' => [ 'code' ], |
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'grant_types_supported' => [ 'authorization_code', 'refresh_token' ], |
| 213 |
'code_challenge_methods_supported' => [ 'S256' ], |
| 214 |
'token_endpoint_auth_methods_supported' => [ 'none' ], |
| 215 |
]; |
| 216 |
} |
| 217 |
|
| 218 |
// -- Dynamic client registration (RFC 7591) -------------------------- |
| 219 |
|
| 220 |
/** |
| 221 |
* Register a public client. We accept the client's redirect_uris and |
| 222 |
* mint a client_id (no secret — public clients rely on PKCE). |
| 223 |
* |
| 224 |
* @param array<string,mixed> $body Parsed JSON registration request. |
| 225 |
* @return array<string,mixed>|\WP_Error |
| 226 |
*/ |
| 227 |
public static function register_client( array $body ) { |
| 228 |
$redirect_uris = isset( $body['redirect_uris'] ) && is_array( $body['redirect_uris'] ) |
| 229 |
? array_values( array_filter( array_map( 'strval', $body['redirect_uris'] ), [ self::class, 'is_valid_redirect_uri' ] ) ) |
| 230 |
: []; |
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|
| 232 |
if ( empty( $redirect_uris ) ) { |
| 233 |
return new \WP_Error( |
| 234 |
'invalid_redirect_uri', |
| 235 |
__( 'At least one valid redirect_uri is required.', 'thinkrank' ), |
| 236 |
[ 'status' => 400 ] |
| 237 |
); |
| 238 |
} |
| 239 |
|
| 240 |
$name = isset( $body['client_name'] ) ? sanitize_text_field( (string) $body['client_name'] ) : 'MCP Client'; |
| 241 |
$client_id = 'trk_' . bin2hex( random_bytes( 16 ) ); |
| 242 |
|
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$state = self::state(); |
| 244 |
$state['clients'][ $client_id ] = [ |
| 245 |
'redirect_uris' => $redirect_uris, |
| 246 |
'name' => $name, |
| 247 |
'created' => time(), |
| 248 |
]; |
| 249 |
$state['clients'] = self::prune_clients( $state ); |
| 250 |
self::save( $state ); |
| 251 |
|
| 252 |
return [ |
| 253 |
'client_id' => $client_id, |
| 254 |
'client_id_issued_at' => time(), |
| 255 |
'redirect_uris' => $redirect_uris, |
| 256 |
'client_name' => $name, |
| 257 |
'token_endpoint_auth_method' => 'none', |
| 258 |
'grant_types' => [ 'authorization_code', 'refresh_token' ], |
| 259 |
'response_types' => [ 'code' ], |
| 260 |
]; |
| 261 |
} |
| 262 |
|
| 263 |
// -- Authorization endpoint ------------------------------------------ |
| 264 |
|
| 265 |
/** |
| 266 |
* Validate an /authorize request's parameters WITHOUT issuing anything. |
| 267 |
* Returns a sanitized param bag on success, or WP_Error on a protocol |
| 268 |
* violation. The caller decides how to surface it (redirect vs error |
| 269 |
* page) based on whether redirect_uri is trustworthy. |
| 270 |
* |
| 271 |
* @param array<string,string> $params Query params. |
| 272 |
* @return array<string,string>|\WP_Error |
| 273 |
*/ |
| 274 |
public static function validate_authorize_request( array $params ) { |
| 275 |
$client_id = isset( $params['client_id'] ) ? (string) $params['client_id'] : ''; |
| 276 |
$redirect_uri = isset( $params['redirect_uri'] ) ? (string) $params['redirect_uri'] : ''; |
| 277 |
$response_type = isset( $params['response_type'] ) ? (string) $params['response_type'] : ''; |
| 278 |
$challenge = isset( $params['code_challenge'] ) ? (string) $params['code_challenge'] : ''; |
| 279 |
$method = isset( $params['code_challenge_method'] ) ? (string) $params['code_challenge_method'] : ''; |
| 280 |
$scope = isset( $params['scope'] ) ? (string) $params['scope'] : 'mcp'; |
| 281 |
$state = isset( $params['state'] ) ? (string) $params['state'] : ''; |
| 282 |
|
| 283 |
$client = self::client( $client_id ); |
| 284 |
if ( null === $client ) { |
| 285 |
return new \WP_Error( 'invalid_client', __( 'Unknown client_id.', 'thinkrank' ), [ 'status' => 400 ] ); |
| 286 |
} |
| 287 |
if ( ! in_array( $redirect_uri, $client['redirect_uris'], true ) ) { |
| 288 |
// redirect_uri mismatch must NOT redirect (open-redirect guard). |
| 289 |
return new \WP_Error( 'invalid_redirect_uri', __( 'redirect_uri does not match a registered value.', 'thinkrank' ), [ 'status' => 400 ] ); |
| 290 |
} |
| 291 |
if ( 'code' !== $response_type ) { |
| 292 |
return new \WP_Error( |
| 293 |
'unsupported_response_type', |
| 294 |
__( 'Only response_type=code is supported.', 'thinkrank' ), |
| 295 |
[ |
| 296 |
'status' => 400, |
| 297 |
'redirectable' => true, |
| 298 |
] |
| 299 |
); |
| 300 |
} |
| 301 |
// OAuth 2.1: PKCE S256 is mandatory for public clients. |
| 302 |
if ( 'S256' !== $method || '' === $challenge ) { |
| 303 |
return new \WP_Error( |
| 304 |
'invalid_request', |
| 305 |
__( 'PKCE with code_challenge_method=S256 is required.', 'thinkrank' ), |
| 306 |
[ |
| 307 |
'status' => 400, |
| 308 |
'redirectable' => true, |
| 309 |
] |
| 310 |
); |
| 311 |
} |
| 312 |
|
| 313 |
return [ |
| 314 |
'client_id' => $client_id, |
| 315 |
'client_name' => $client['name'], |
| 316 |
'redirect_uri' => $redirect_uri, |
| 317 |
'code_challenge' => $challenge, |
| 318 |
'scope' => self::normalize_scope( $scope ), |
| 319 |
'state' => $state, |
| 320 |
]; |
| 321 |
} |
| 322 |
|
| 323 |
/** |
| 324 |
* Issue an authorization code after the admin approves consent. Binds |
| 325 |
* the code to the client, redirect_uri, PKCE challenge, granted scope, |
| 326 |
* and the approving user. Single-use, 60 s TTL. |
| 327 |
* |
| 328 |
* @param array<string,string> $req Output of validate_authorize_request(). |
| 329 |
* @param int $user_id Approving admin user id. |
| 330 |
* @return string The authorization code. |
| 331 |
*/ |
| 332 |
public static function issue_code( array $req, int $user_id ): string { |
| 333 |
$code = bin2hex( random_bytes( 32 ) ); |
| 334 |
$state = self::state(); |
| 335 |
$state['codes'][ $code ] = [ |
| 336 |
'client_id' => $req['client_id'], |
| 337 |
'redirect_uri' => $req['redirect_uri'], |
| 338 |
'challenge' => $req['code_challenge'], |
| 339 |
'scope' => $req['scope'], |
| 340 |
'user_id' => $user_id, |
| 341 |
'expires' => time() + self::CODE_TTL, |
| 342 |
]; |
| 343 |
self::save( $state ); |
| 344 |
return $code; |
| 345 |
} |
| 346 |
|
| 347 |
// -- Token endpoint -------------------------------------------------- |
| 348 |
|
| 349 |
/** |
| 350 |
* Exchange an authorization code (+ PKCE verifier) for tokens, or a |
| 351 |
* refresh token for a fresh access token. |
| 352 |
* |
| 353 |
* @param array<string,string> $body POST body params. |
| 354 |
* @return array<string,mixed>|\WP_Error |
| 355 |
*/ |
| 356 |
public static function exchange_token( array $body ) { |
| 357 |
$grant = isset( $body['grant_type'] ) ? (string) $body['grant_type'] : ''; |
| 358 |
|
| 359 |
if ( 'authorization_code' === $grant ) { |
| 360 |
return self::grant_authorization_code( $body ); |
| 361 |
} |
| 362 |
if ( 'refresh_token' === $grant ) { |
| 363 |
return self::grant_refresh_token( $body ); |
| 364 |
} |
| 365 |
return self::oauth_error( 'unsupported_grant_type', 'Unsupported grant_type.' ); |
| 366 |
} |
| 367 |
|
| 368 |
/** |
| 369 |
* authorization_code grant: verify the code + PKCE, mint tokens. |
| 370 |
* |
| 371 |
* @param array<string,string> $body POST body. |
| 372 |
* @return array<string,mixed>|\WP_Error |
| 373 |
*/ |
| 374 |
private static function grant_authorization_code( array $body ) { |
| 375 |
$code = isset( $body['code'] ) ? (string) $body['code'] : ''; |
| 376 |
$client_id = isset( $body['client_id'] ) ? (string) $body['client_id'] : ''; |
| 377 |
$redirect_uri = isset( $body['redirect_uri'] ) ? (string) $body['redirect_uri'] : ''; |
| 378 |
$verifier = isset( $body['code_verifier'] ) ? (string) $body['code_verifier'] : ''; |
| 379 |
|
| 380 |
$state = self::state(); |
| 381 |
if ( '' === $code || ! isset( $state['codes'][ $code ] ) ) { |
| 382 |
return self::oauth_error( 'invalid_grant', 'Unknown or expired authorization code.' ); |
| 383 |
} |
| 384 |
$entry = $state['codes'][ $code ]; |
| 385 |
|
| 386 |
// Single-use: remove immediately whether or not verification passes. |
| 387 |
unset( $state['codes'][ $code ] ); |
| 388 |
self::save( $state ); |
| 389 |
|
| 390 |
if ( $entry['expires'] < time() ) { |
| 391 |
return self::oauth_error( 'invalid_grant', 'Authorization code expired.' ); |
| 392 |
} |
| 393 |
if ( ! hash_equals( (string) $entry['client_id'], $client_id ) ) { |
| 394 |
return self::oauth_error( 'invalid_grant', 'client_id mismatch.' ); |
| 395 |
} |
| 396 |
if ( ! hash_equals( (string) $entry['redirect_uri'], $redirect_uri ) ) { |
| 397 |
return self::oauth_error( 'invalid_grant', 'redirect_uri mismatch.' ); |
| 398 |
} |
| 399 |
// PKCE S256: BASE64URL(SHA256(verifier)) must equal the stored challenge. |
| 400 |
if ( '' === $verifier || ! hash_equals( (string) $entry['challenge'], self::s256( $verifier ) ) ) { |
| 401 |
return self::oauth_error( 'invalid_grant', 'PKCE verification failed.' ); |
| 402 |
} |
| 403 |
|
| 404 |
return self::mint_tokens( (string) $entry['client_id'], (string) $entry['scope'], (int) $entry['user_id'] ); |
| 405 |
} |
| 406 |
|
| 407 |
/** |
| 408 |
* refresh_token grant: rotate the refresh token, issue a fresh access |
| 409 |
* token. The old refresh + its access token are revoked. |
| 410 |
* |
| 411 |
* @param array<string,string> $body POST body. |
| 412 |
* @return array<string,mixed>|\WP_Error |
| 413 |
*/ |
| 414 |
private static function grant_refresh_token( array $body ) { |
| 415 |
$refresh = isset( $body['refresh_token'] ) ? (string) $body['refresh_token'] : ''; |
| 416 |
$client_id = isset( $body['client_id'] ) ? (string) $body['client_id'] : ''; |
| 417 |
|
| 418 |
$state = self::state(); |
| 419 |
$rhash = self::hash( $refresh ); |
| 420 |
if ( '' === $refresh || ! isset( $state['refresh'][ $rhash ] ) ) { |
| 421 |
return self::oauth_error( 'invalid_grant', 'Unknown refresh token.' ); |
| 422 |
} |
| 423 |
$entry = $state['refresh'][ $rhash ]; |
| 424 |
if ( '' !== $client_id && ! hash_equals( (string) $entry['client_id'], $client_id ) ) { |
| 425 |
return self::oauth_error( 'invalid_grant', 'client_id mismatch.' ); |
| 426 |
} |
| 427 |
|
| 428 |
// Rotate: drop old refresh + its access token. |
| 429 |
unset( $state['refresh'][ $rhash ] ); |
| 430 |
if ( isset( $entry['access_hash'] ) ) { |
| 431 |
unset( $state['tokens'][ $entry['access_hash'] ] ); |
| 432 |
} |
| 433 |
self::save( $state ); |
| 434 |
|
| 435 |
return self::mint_tokens( (string) $entry['client_id'], (string) $entry['scope'], (int) $entry['user_id'] ); |
| 436 |
} |
| 437 |
|
| 438 |
/** |
| 439 |
* Mint an access + refresh token pair, store them hashed, and return |
| 440 |
* the RFC 6749 token response with the raw values. |
| 441 |
* |
| 442 |
* @param string $client_id Client id. |
| 443 |
* @param string $scope Granted scope string. |
| 444 |
* @param int $user_id Resource-owner user id. |
| 445 |
* @return array<string,mixed> |
| 446 |
*/ |
| 447 |
private static function mint_tokens( string $client_id, string $scope, int $user_id ): array { |
| 448 |
$access = bin2hex( random_bytes( 32 ) ); |
| 449 |
$refresh = bin2hex( random_bytes( 32 ) ); |
| 450 |
$ahash = self::hash( $access ); |
| 451 |
$rhash = self::hash( $refresh ); |
| 452 |
|
| 453 |
$state = self::state(); |
| 454 |
$state['tokens'][ $ahash ] = [ |
| 455 |
'client_id' => $client_id, |
| 456 |
'scope' => $scope, |
| 457 |
'user_id' => $user_id, |
| 458 |
'expires' => time() + self::ACCESS_TTL, |
| 459 |
'refresh' => $rhash, |
| 460 |
]; |
| 461 |
$state['refresh'][ $rhash ] = [ |
| 462 |
'access_hash' => $ahash, |
| 463 |
'client_id' => $client_id, |
| 464 |
'scope' => $scope, |
| 465 |
'user_id' => $user_id, |
| 466 |
'expires' => time() + self::REFRESH_TTL, |
| 467 |
]; |
| 468 |
self::save( $state ); |
| 469 |
|
| 470 |
return [ |
| 471 |
'access_token' => $access, |
| 472 |
'token_type' => 'Bearer', |
| 473 |
'expires_in' => self::ACCESS_TTL, |
| 474 |
'refresh_token' => $refresh, |
| 475 |
'scope' => $scope, |
| 476 |
]; |
| 477 |
} |
| 478 |
|
| 479 |
// -- Access-token validation (called by Mcp_Server) ------------------ |
| 480 |
|
| 481 |
/** |
| 482 |
* Validate a bearer access token presented to the MCP endpoint. |
| 483 |
* Returns the token's grant record (scope, user_id, client_id) when |
| 484 |
* valid + unexpired, or null. Constant-time via hashed lookup. |
| 485 |
* |
| 486 |
* @param string $token Raw access token from the Authorization header. |
| 487 |
* @return array{client_id:string,scope:string,user_id:int}|null |
| 488 |
*/ |
| 489 |
public static function validate_token( string $token ): ?array { |
| 490 |
if ( '' === $token ) { |
| 491 |
return null; |
| 492 |
} |
| 493 |
$state = self::state(); |
| 494 |
$hash = self::hash( $token ); |
| 495 |
if ( ! isset( $state['tokens'][ $hash ] ) ) { |
| 496 |
return null; |
| 497 |
} |
| 498 |
$entry = $state['tokens'][ $hash ]; |
| 499 |
if ( (int) $entry['expires'] < time() ) { |
| 500 |
return null; |
| 501 |
} |
| 502 |
|
| 503 |
// Record activity against the owning client so the "Connected AI apps" |
| 504 |
// list can show a last-used date. Throttled + stored on the client |
| 505 |
// record so it survives access-token rotation. |
| 506 |
$client_id = (string) $entry['client_id']; |
| 507 |
$now = time(); |
| 508 |
if ( isset( $state['clients'][ $client_id ] ) && is_array( $state['clients'][ $client_id ] ) ) { |
| 509 |
$last = isset( $state['clients'][ $client_id ]['last_used'] ) ? (int) $state['clients'][ $client_id ]['last_used'] : 0; |
| 510 |
if ( $now - $last >= self::LAST_USED_THROTTLE ) { |
| 511 |
$state['clients'][ $client_id ]['last_used'] = $now; |
| 512 |
self::save( $state ); |
| 513 |
} |
| 514 |
} |
| 515 |
|
| 516 |
return [ |
| 517 |
'client_id' => $client_id, |
| 518 |
'scope' => (string) $entry['scope'], |
| 519 |
'user_id' => (int) $entry['user_id'], |
| 520 |
]; |
| 521 |
} |
| 522 |
|
| 523 |
/** |
| 524 |
* Whether a granted scope string is read-only. `mcp` is the umbrella |
| 525 |
* scope that grants read+write, so only a grant that carries NEITHER |
| 526 |
* `write` NOR `mcp` — i.e. `read` alone — is read-only. |
| 527 |
* |
| 528 |
* @param string $scope Space-separated scope string. |
| 529 |
* @return bool |
| 530 |
*/ |
| 531 |
public static function scope_is_read_only( string $scope ): bool { |
| 532 |
$parts = preg_split( '/\s+/', trim( $scope ) ); |
| 533 |
$parts = is_array( $parts ) ? $parts : []; |
| 534 |
return ! in_array( 'write', $parts, true ) && ! in_array( 'mcp', $parts, true ); |
| 535 |
} |
| 536 |
|
| 537 |
/** |
| 538 |
* Revoke every OAuth token + client (used by disconnect). |
| 539 |
* |
| 540 |
* @return void |
| 541 |
*/ |
| 542 |
public static function revoke_all(): void { |
| 543 |
delete_option( self::OPTION ); |
| 544 |
} |
| 545 |
|
| 546 |
/** |
| 547 |
* The OAuth clients currently holding a live grant, for the "Connected AI |
| 548 |
* apps" list. A client counts as connected while it holds an unexpired |
| 549 |
* refresh token (the durable 30-day grant) or access token; a client that |
| 550 |
* only registered but never completed consent is excluded. One entry per |
| 551 |
* client_id, newest connection first. |
| 552 |
* |
| 553 |
* @return array<int,array{client_id:string,name:string,scope:string,read_only:bool,user_id:int,connected_at:int,last_used:int}> |
| 554 |
*/ |
| 555 |
public static function connected_apps(): array { |
| 556 |
$state = self::state(); |
| 557 |
|
| 558 |
// Collect the scope + approving user per active client. Refresh tokens |
| 559 |
// are the durable grant, so prefer them; fall back to access tokens. |
| 560 |
$active = []; |
| 561 |
foreach ( [ 'refresh', 'tokens' ] as $bucket ) { |
| 562 |
foreach ( $state[ $bucket ] as $entry ) { |
| 563 |
$cid = isset( $entry['client_id'] ) ? (string) $entry['client_id'] : ''; |
| 564 |
if ( '' === $cid || isset( $active[ $cid ] ) ) { |
| 565 |
continue; |
| 566 |
} |
| 567 |
$active[ $cid ] = [ |
| 568 |
'scope' => isset( $entry['scope'] ) ? (string) $entry['scope'] : 'mcp', |
| 569 |
'user_id' => isset( $entry['user_id'] ) ? (int) $entry['user_id'] : 0, |
| 570 |
]; |
| 571 |
} |
| 572 |
} |
| 573 |
|
| 574 |
$apps = []; |
| 575 |
foreach ( $active as $cid => $info ) { |
| 576 |
$client = isset( $state['clients'][ $cid ] ) && is_array( $state['clients'][ $cid ] ) ? $state['clients'][ $cid ] : []; |
| 577 |
$apps[] = [ |
| 578 |
'client_id' => $cid, |
| 579 |
'name' => isset( $client['name'] ) ? (string) $client['name'] : __( 'MCP Client', 'thinkrank' ), |
| 580 |
'scope' => $info['scope'], |
| 581 |
'read_only' => self::scope_is_read_only( $info['scope'] ), |
| 582 |
'user_id' => $info['user_id'], |
| 583 |
'connected_at' => isset( $client['created'] ) ? (int) $client['created'] : 0, |
| 584 |
'last_used' => isset( $client['last_used'] ) ? (int) $client['last_used'] : 0, |
| 585 |
]; |
| 586 |
} |
| 587 |
|
| 588 |
// Newest connection first. |
| 589 |
usort( |
| 590 |
$apps, |
| 591 |
static function ( array $a, array $b ): int { |
| 592 |
return $b['connected_at'] <=> $a['connected_at']; |
| 593 |
} |
| 594 |
); |
| 595 |
|
| 596 |
return $apps; |
| 597 |
} |
| 598 |
|
| 599 |
/** |
| 600 |
* Revoke a single OAuth client's ACCESS — drops its access tokens, refresh |
| 601 |
* tokens, and any pending codes, cutting that one app off immediately while |
| 602 |
* leaving every other connection intact. It disappears from |
| 603 |
* connected_apps() (which keys off live tokens), so the UI shows it gone. |
| 604 |
* |
| 605 |
* The client's dynamic registration (its client_id + redirect_uris) is |
| 606 |
* intentionally KEPT: MCP clients such as ChatGPT cache the client_id from |
| 607 |
* their first registration and reuse it on reconnect, hitting /authorize |
| 608 |
* with that id rather than registering afresh. If we deleted the |
| 609 |
* registration, that reconnect would fail with "Unknown client_id". Keeping |
| 610 |
* it lets the app re-authorize — which still requires fresh admin consent |
| 611 |
* (and mints brand-new tokens), so revocation loses nothing. |
| 612 |
* |
| 613 |
* @param string $client_id The client whose access to revoke. |
| 614 |
* @return bool True if any live grant was removed. |
| 615 |
*/ |
| 616 |
public static function revoke_client( string $client_id ): bool { |
| 617 |
if ( '' === $client_id ) { |
| 618 |
return false; |
| 619 |
} |
| 620 |
$state = self::state(); |
| 621 |
$removed = false; |
| 622 |
|
| 623 |
foreach ( [ 'tokens', 'refresh', 'codes' ] as $bucket ) { |
| 624 |
foreach ( $state[ $bucket ] as $key => $entry ) { |
| 625 |
if ( isset( $entry['client_id'] ) && (string) $entry['client_id'] === $client_id ) { |
| 626 |
unset( $state[ $bucket ][ $key ] ); |
| 627 |
$removed = true; |
| 628 |
} |
| 629 |
} |
| 630 |
} |
| 631 |
|
| 632 |
if ( $removed ) { |
| 633 |
self::save( $state ); |
| 634 |
} |
| 635 |
return $removed; |
| 636 |
} |
| 637 |
|
| 638 |
// -- State + helpers ------------------------------------------------- |
| 639 |
|
| 640 |
/** |
| 641 |
* Load state with defaults, pruning expired codes/tokens/refresh |
| 642 |
* entries on the way out so the option can't grow unbounded. |
| 643 |
* |
| 644 |
* @return array<string,array<string,mixed>> |
| 645 |
*/ |
| 646 |
private static function state(): array { |
| 647 |
$stored = get_option( self::OPTION, [] ); |
| 648 |
if ( ! is_array( $stored ) ) { |
| 649 |
$stored = []; |
| 650 |
} |
| 651 |
$state = [ |
| 652 |
'clients' => isset( $stored['clients'] ) && is_array( $stored['clients'] ) ? $stored['clients'] : [], |
| 653 |
'codes' => isset( $stored['codes'] ) && is_array( $stored['codes'] ) ? $stored['codes'] : [], |
| 654 |
'tokens' => isset( $stored['tokens'] ) && is_array( $stored['tokens'] ) ? $stored['tokens'] : [], |
| 655 |
'refresh' => isset( $stored['refresh'] ) && is_array( $stored['refresh'] ) ? $stored['refresh'] : [], |
| 656 |
]; |
| 657 |
|
| 658 |
$now = time(); |
| 659 |
foreach ( $state['codes'] as $k => $v ) { |
| 660 |
if ( ! isset( $v['expires'] ) || $v['expires'] < $now ) { |
| 661 |
unset( $state['codes'][ $k ] ); |
| 662 |
} |
| 663 |
} |
| 664 |
foreach ( $state['tokens'] as $k => $v ) { |
| 665 |
if ( ! isset( $v['expires'] ) || $v['expires'] < $now ) { |
| 666 |
unset( $state['tokens'][ $k ] ); |
| 667 |
} |
| 668 |
} |
| 669 |
foreach ( $state['refresh'] as $k => $v ) { |
| 670 |
if ( isset( $v['expires'] ) && $v['expires'] < $now ) { |
| 671 |
unset( $state['refresh'][ $k ] ); |
| 672 |
} |
| 673 |
} |
| 674 |
return $state; |
| 675 |
} |
| 676 |
|
| 677 |
/** |
| 678 |
* Persist state (autoload off — hot-write, request-scoped option). |
| 679 |
* |
| 680 |
* @param array<string,mixed> $state State to persist. |
| 681 |
* @return void |
| 682 |
*/ |
| 683 |
private static function save( array $state ): void { |
| 684 |
update_option( self::OPTION, $state, false ); |
| 685 |
} |
| 686 |
|
| 687 |
/** |
| 688 |
* Look up a registered client. |
| 689 |
* |
| 690 |
* @param string $client_id Client id. |
| 691 |
* @return array{redirect_uris:string[],name:string,created:int}|null |
| 692 |
*/ |
| 693 |
private static function client( string $client_id ): ?array { |
| 694 |
if ( '' === $client_id ) { |
| 695 |
return null; |
| 696 |
} |
| 697 |
$clients = self::state()['clients']; |
| 698 |
if ( ! isset( $clients[ $client_id ] ) || ! is_array( $clients[ $client_id ] ) ) { |
| 699 |
return null; |
| 700 |
} |
| 701 |
$c = $clients[ $client_id ]; |
| 702 |
return [ |
| 703 |
'redirect_uris' => isset( $c['redirect_uris'] ) && is_array( $c['redirect_uris'] ) ? array_map( 'strval', $c['redirect_uris'] ) : [], |
| 704 |
'name' => isset( $c['name'] ) ? (string) $c['name'] : 'MCP Client', |
| 705 |
'created' => isset( $c['created'] ) ? (int) $c['created'] : 0, |
| 706 |
]; |
| 707 |
} |
| 708 |
|
| 709 |
/** |
| 710 |
* Bound the registered-client list. Drops abandoned registrations past |
| 711 |
* CLIENT_TTL first, then — if still over MAX_CLIENTS — the oldest of what |
| 712 |
* is left. A client referenced by a live code, access token, or refresh |
| 713 |
* token is NEVER dropped: evicting one would break a working connection, |
| 714 |
* so a site legitimately holding more than MAX_CLIENTS live grants keeps |
| 715 |
* them all and the cap simply stops applying to that remainder. |
| 716 |
* |
| 717 |
* @param array<string,array<string,mixed>> $state Full state (clients + grant buckets). |
| 718 |
* @return array<string,array<string,mixed>> The clients array to store. |
| 719 |
*/ |
| 720 |
private static function prune_clients( array $state ): array { |
| 721 |
$clients = $state['clients']; |
| 722 |
|
| 723 |
$in_use = []; |
| 724 |
foreach ( [ 'codes', 'tokens', 'refresh' ] as $bucket ) { |
| 725 |
foreach ( $state[ $bucket ] as $entry ) { |
| 726 |
if ( is_array( $entry ) && isset( $entry['client_id'] ) ) { |
| 727 |
$in_use[ (string) $entry['client_id'] ] = true; |
| 728 |
} |
| 729 |
} |
| 730 |
} |
| 731 |
|
| 732 |
$now = time(); |
| 733 |
foreach ( $clients as $id => $client ) { |
| 734 |
$created = isset( $client['created'] ) ? (int) $client['created'] : 0; |
| 735 |
if ( ! isset( $in_use[ $id ] ) && $created + self::CLIENT_TTL < $now ) { |
| 736 |
unset( $clients[ $id ] ); |
| 737 |
} |
| 738 |
} |
| 739 |
|
| 740 |
if ( count( $clients ) <= self::MAX_CLIENTS ) { |
| 741 |
return $clients; |
| 742 |
} |
| 743 |
|
| 744 |
// Still over the cap — evict the oldest unused registrations. |
| 745 |
$evictable = array_filter( |
| 746 |
$clients, |
| 747 |
static function ( $id ) use ( $in_use ) { |
| 748 |
return ! isset( $in_use[ $id ] ); |
| 749 |
}, |
| 750 |
ARRAY_FILTER_USE_KEY |
| 751 |
); |
| 752 |
uasort( |
| 753 |
$evictable, |
| 754 |
static function ( $a, $b ) { |
| 755 |
return ( isset( $a['created'] ) ? (int) $a['created'] : 0 ) <=> ( isset( $b['created'] ) ? (int) $b['created'] : 0 ); |
| 756 |
} |
| 757 |
); |
| 758 |
foreach ( array_keys( $evictable ) as $id ) { |
| 759 |
if ( count( $clients ) <= self::MAX_CLIENTS ) { |
| 760 |
break; |
| 761 |
} |
| 762 |
unset( $clients[ $id ] ); |
| 763 |
} |
| 764 |
|
| 765 |
return $clients; |
| 766 |
} |
| 767 |
|
| 768 |
/** |
| 769 |
* SHA-256 hash used to store tokens at rest. |
| 770 |
* |
| 771 |
* @param string $value Raw secret. |
| 772 |
* @return string |
| 773 |
*/ |
| 774 |
private static function hash( string $value ): string { |
| 775 |
return hash( 'sha256', $value ); |
| 776 |
} |
| 777 |
|
| 778 |
/** |
| 779 |
* BASE64URL(SHA256(verifier)) — the PKCE S256 transformation. |
| 780 |
* |
| 781 |
* @param string $verifier PKCE code verifier. |
| 782 |
* @return string |
| 783 |
*/ |
| 784 |
private static function s256( string $verifier ): string { |
| 785 |
// phpcs:ignore WordPress.PHP.DiscouragedPHPFunctions.obfuscation_base64_encode -- base64url of the PKCE challenge, mandated by RFC 7636. |
| 786 |
return rtrim( strtr( base64_encode( hash( 'sha256', $verifier, true ) ), '+/', '-_' ), '=' ); |
| 787 |
} |
| 788 |
|
| 789 |
/** |
| 790 |
* Constrain a requested scope to what we support. Defaults to `mcp` |
| 791 |
* (read+write umbrella). |
| 792 |
* |
| 793 |
* @param string $requested Requested scope string. |
| 794 |
* @return string |
| 795 |
*/ |
| 796 |
private static function normalize_scope( string $requested ): string { |
| 797 |
$parts = preg_split( '/\s+/', trim( $requested ) ); |
| 798 |
$parts = is_array( $parts ) ? $parts : []; |
| 799 |
$parts = array_values( array_intersect( $parts, self::SUPPORTED_SCOPES ) ); |
| 800 |
if ( empty( $parts ) ) { |
| 801 |
return 'mcp'; |
| 802 |
} |
| 803 |
return implode( ' ', $parts ); |
| 804 |
} |
| 805 |
|
| 806 |
/** |
| 807 |
* Whether a redirect_uri is structurally acceptable (http(s) or a |
| 808 |
* native-client custom scheme). |
| 809 |
* |
| 810 |
* @param string $uri Candidate redirect URI. |
| 811 |
* @return bool |
| 812 |
*/ |
| 813 |
private static function is_valid_redirect_uri( string $uri ): bool { |
| 814 |
$uri = trim( $uri ); |
| 815 |
if ( '' === $uri ) { |
| 816 |
return false; |
| 817 |
} |
| 818 |
return (bool) preg_match( '#^[a-zA-Z][a-zA-Z0-9+.\-]*://#', $uri ); |
| 819 |
} |
| 820 |
|
| 821 |
/** |
| 822 |
* Build a WP_Error whose data carries an OAuth 2.0 `error` code so the |
| 823 |
* token route can render the RFC 6749 error body. |
| 824 |
* |
| 825 |
* @param string $code OAuth error code (invalid_grant, ...). |
| 826 |
* @param string $message Human-readable description. |
| 827 |
* @return \WP_Error |
| 828 |
*/ |
| 829 |
private static function oauth_error( string $code, string $message ): \WP_Error { |
| 830 |
return new \WP_Error( |
| 831 |
$code, |
| 832 |
$message, |
| 833 |
[ |
| 834 |
'status' => 400, |
| 835 |
'error' => $code, |
| 836 |
'error_description' => $message, |
| 837 |
] |
| 838 |
); |
| 839 |
} |
| 840 |
} |
| 841 |
|
