| 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. See the security contract and |
| 9 |
* the end-to-end flow notes below. |
| 10 |
* |
| 11 |
* Flow: unauthenticated MCP call -> 401 + WWW-Authenticate (Mcp_Server) -> |
| 12 |
* client fetches /.well-known/oauth-protected-resource + oauth-authorization- |
| 13 |
* server -> dynamic registration (RFC 7591) -> /authorize (admin consent + |
| 14 |
* PKCE) -> /token (code + verifier -> access + refresh) -> MCP calls with |
| 15 |
* `Authorization: Bearer <access>` validated by validate_token(). |
| 16 |
* |
| 17 |
* Security contract: |
| 18 |
* - PKCE S256 REQUIRED (OAuth 2.1 public clients); codes are single-use, |
| 19 |
* 60 s TTL, bound to client_id + redirect_uri + challenge. |
| 20 |
* - /authorize gates on manage_options -- only an admin can grant access, |
| 21 |
* matching the pairing token's admin-only mint (anon -> wp-login first). |
| 22 |
* - Access/refresh tokens stored only as SHA-256 hashes; raw value exists |
| 23 |
* solely in the /token response. Constant-time comparison. |
| 24 |
* - Tokens carry the read/write scope model; a read-only grant refuses |
| 25 |
* every write tool, exactly like a read-only pairing token. |
| 26 |
* - Off until an admin approves consent; a fresh install exposes discovery |
| 27 |
* metadata but issues nothing. |
| 28 |
* |
| 29 |
* State lives in the `xspeed_mcp_oauth` option (clients, codes, tokens, |
| 30 |
* refresh -- keyed by id or sha256 of the secret); expired codes/tokens are |
| 31 |
* pruned lazily on every read. |
| 32 |
* |
| 33 |
* @package XSpeed |
| 34 |
*/ |
| 35 |
|
| 36 |
declare(strict_types=1); |
| 37 |
|
| 38 |
namespace XSpeed\Modules\Mcp; |
| 39 |
|
| 40 |
defined( 'ABSPATH' ) || exit; |
| 41 |
|
| 42 |
final class Mcp_OAuth { |
| 43 |
|
| 44 |
/** Option key holding all OAuth server state. */ |
| 45 |
public const OPTION = 'xspeed_mcp_oauth'; |
| 46 |
|
| 47 |
/** Authorization-code lifetime (seconds). Deliberately short. */ |
| 48 |
private const CODE_TTL = 60; |
| 49 |
|
| 50 |
/** Access-token lifetime (seconds) -- 1 hour, refreshable. */ |
| 51 |
private const ACCESS_TTL = 3600; |
| 52 |
|
| 53 |
/** Refresh-token lifetime (seconds) -- 30 days. */ |
| 54 |
private const REFRESH_TTL = 2592000; |
| 55 |
|
| 56 |
/** Scopes we advertise + honor. `mcp` is the umbrella scope MCP clients request. */ |
| 57 |
private const SUPPORTED_SCOPES = array( 'mcp', 'read', 'write' ); |
| 58 |
|
| 59 |
// -- URLs ------------------------------------------------------------ |
| 60 |
|
| 61 |
/** Base site URL used as the OAuth issuer (no trailing slash). */ |
| 62 |
public static function issuer(): string { |
| 63 |
return untrailingslashit( home_url() ); |
| 64 |
} |
| 65 |
|
| 66 |
/** The protected resource identifier -- the MCP endpoint URL. */ |
| 67 |
public static function resource(): string { |
| 68 |
return Mcp_Pairing::site_endpoint(); |
| 69 |
} |
| 70 |
|
| 71 |
/** |
| 72 |
* The browser-facing authorize page. Served OUTSIDE the REST API (via a |
| 73 |
* rewrite rule) so standard cookie auth works after the wp-login |
| 74 |
* round-trip — a REST route would see the cookie without a nonce and |
| 75 |
* treat the admin as logged-out, looping back to login. |
| 76 |
*/ |
| 77 |
public static function authorize_url(): string { |
| 78 |
return home_url( '/xspeed/authorize' ); |
| 79 |
} |
| 80 |
|
| 81 |
public static function token_url(): string { |
| 82 |
return rest_url( 'xspeed/v1/mcp/oauth/token' ); |
| 83 |
} |
| 84 |
|
| 85 |
public static function register_url(): string { |
| 86 |
return rest_url( 'xspeed/v1/mcp/oauth/register' ); |
| 87 |
} |
| 88 |
|
| 89 |
// -- Discovery documents (RFC 8414 / RFC 9728) ----------------------- |
| 90 |
|
| 91 |
/** |
| 92 |
* RFC 9728 protected-resource metadata -- tells the client which |
| 93 |
* authorization server(s) protect the MCP endpoint (this site). |
| 94 |
* |
| 95 |
* @return array<string,mixed> |
| 96 |
*/ |
| 97 |
public static function protected_resource_metadata(): array { |
| 98 |
return array( |
| 99 |
'resource' => self::resource(), |
| 100 |
'authorization_servers' => array( self::issuer() ), |
| 101 |
'scopes_supported' => self::SUPPORTED_SCOPES, |
| 102 |
'bearer_methods_supported' => array( 'header' ), |
| 103 |
); |
| 104 |
} |
| 105 |
|
| 106 |
/** |
| 107 |
* RFC 8414 authorization-server metadata -- the endpoint map + the |
| 108 |
* capabilities we actually implement (auth-code grant, PKCE S256, |
| 109 |
* dynamic registration, refresh tokens). |
| 110 |
* |
| 111 |
* @return array<string,mixed> |
| 112 |
*/ |
| 113 |
public static function authorization_server_metadata(): array { |
| 114 |
return array( |
| 115 |
'issuer' => self::issuer(), |
| 116 |
'authorization_endpoint' => self::authorize_url(), |
| 117 |
'token_endpoint' => self::token_url(), |
| 118 |
'registration_endpoint' => self::register_url(), |
| 119 |
'scopes_supported' => self::SUPPORTED_SCOPES, |
| 120 |
'response_types_supported' => array( 'code' ), |
| 121 |
'grant_types_supported' => array( 'authorization_code', 'refresh_token' ), |
| 122 |
'code_challenge_methods_supported' => array( 'S256' ), |
| 123 |
'token_endpoint_auth_methods_supported' => array( 'none' ), |
| 124 |
); |
| 125 |
} |
| 126 |
|
| 127 |
// -- Dynamic client registration (RFC 7591) -------------------------- |
| 128 |
|
| 129 |
/** |
| 130 |
* Register a public client. We accept the client's redirect_uris and |
| 131 |
* mint a client_id (no secret -- public clients rely on PKCE). Minimal |
| 132 |
* metadata is echoed back per RFC 7591. |
| 133 |
* |
| 134 |
* @param array<string,mixed> $body Parsed JSON registration request. |
| 135 |
* @return array<string,mixed>|\WP_Error |
| 136 |
*/ |
| 137 |
public static function register_client( array $body ) { |
| 138 |
$redirect_uris = isset( $body['redirect_uris'] ) && is_array( $body['redirect_uris'] ) |
| 139 |
? array_values( array_filter( array_map( 'strval', $body['redirect_uris'] ), array( self::class, 'is_valid_redirect_uri' ) ) ) |
| 140 |
: array(); |
| 141 |
|
| 142 |
if ( empty( $redirect_uris ) ) { |
| 143 |
return new \WP_Error( |
| 144 |
'invalid_redirect_uri', |
| 145 |
__( 'At least one valid redirect_uri is required.', 'xspeed' ), |
| 146 |
array( 'status' => 400 ) |
| 147 |
); |
| 148 |
} |
| 149 |
|
| 150 |
$name = isset( $body['client_name'] ) ? sanitize_text_field( (string) $body['client_name'] ) : 'MCP Client'; |
| 151 |
$client_id = 'xsc_' . bin2hex( random_bytes( 16 ) ); |
| 152 |
|
| 153 |
$state = self::state(); |
| 154 |
$state['clients'][ $client_id ] = array( |
| 155 |
'redirect_uris' => $redirect_uris, |
| 156 |
'name' => $name, |
| 157 |
'created' => time(), |
| 158 |
); |
| 159 |
self::save( $state ); |
| 160 |
|
| 161 |
return array( |
| 162 |
'client_id' => $client_id, |
| 163 |
'client_id_issued_at' => time(), |
| 164 |
'redirect_uris' => $redirect_uris, |
| 165 |
'client_name' => $name, |
| 166 |
'token_endpoint_auth_method' => 'none', |
| 167 |
'grant_types' => array( 'authorization_code', 'refresh_token' ), |
| 168 |
'response_types' => array( 'code' ), |
| 169 |
); |
| 170 |
} |
| 171 |
|
| 172 |
// -- Authorization endpoint ------------------------------------------ |
| 173 |
|
| 174 |
/** |
| 175 |
* Validate an /authorize request's parameters WITHOUT issuing anything. |
| 176 |
* Returns a sanitized param bag on success, or WP_Error on a protocol |
| 177 |
* violation the client must fix. The caller (route handler) decides how |
| 178 |
* to surface it (redirect vs error page) based on whether redirect_uri |
| 179 |
* is trustworthy. |
| 180 |
* |
| 181 |
* @param array<string,string> $params Query params. |
| 182 |
* @return array<string,string>|\WP_Error |
| 183 |
*/ |
| 184 |
public static function validate_authorize_request( array $params ) { |
| 185 |
$client_id = isset( $params['client_id'] ) ? (string) $params['client_id'] : ''; |
| 186 |
$redirect_uri = isset( $params['redirect_uri'] ) ? (string) $params['redirect_uri'] : ''; |
| 187 |
$response_type = isset( $params['response_type'] ) ? (string) $params['response_type'] : ''; |
| 188 |
$challenge = isset( $params['code_challenge'] ) ? (string) $params['code_challenge'] : ''; |
| 189 |
$method = isset( $params['code_challenge_method'] ) ? (string) $params['code_challenge_method'] : ''; |
| 190 |
$scope = isset( $params['scope'] ) ? (string) $params['scope'] : 'mcp'; |
| 191 |
$state = isset( $params['state'] ) ? (string) $params['state'] : ''; |
| 192 |
|
| 193 |
$client = self::client( $client_id ); |
| 194 |
if ( null === $client ) { |
| 195 |
return new \WP_Error( 'invalid_client', __( 'Unknown client_id.', 'xspeed' ), array( 'status' => 400 ) ); |
| 196 |
} |
| 197 |
if ( ! in_array( $redirect_uri, $client['redirect_uris'], true ) ) { |
| 198 |
// redirect_uri mismatch must NOT redirect (open-redirect guard). |
| 199 |
return new \WP_Error( 'invalid_redirect_uri', __( 'redirect_uri does not match a registered value.', 'xspeed' ), array( 'status' => 400 ) ); |
| 200 |
} |
| 201 |
if ( 'code' !== $response_type ) { |
| 202 |
return new \WP_Error( 'unsupported_response_type', __( 'Only response_type=code is supported.', 'xspeed' ), array( 'status' => 400, 'redirectable' => true ) ); |
| 203 |
} |
| 204 |
// OAuth 2.1: PKCE S256 is mandatory for public clients. |
| 205 |
if ( 'S256' !== $method || '' === $challenge ) { |
| 206 |
return new \WP_Error( 'invalid_request', __( 'PKCE with code_challenge_method=S256 is required.', 'xspeed' ), array( 'status' => 400, 'redirectable' => true ) ); |
| 207 |
} |
| 208 |
|
| 209 |
return array( |
| 210 |
'client_id' => $client_id, |
| 211 |
'client_name' => $client['name'], |
| 212 |
'redirect_uri' => $redirect_uri, |
| 213 |
'code_challenge' => $challenge, |
| 214 |
'scope' => self::normalize_scope( $scope ), |
| 215 |
'state' => $state, |
| 216 |
); |
| 217 |
} |
| 218 |
|
| 219 |
/** |
| 220 |
* Issue an authorization code after the admin approves consent. Binds |
| 221 |
* the code to the client, redirect_uri, PKCE challenge, granted scope, |
| 222 |
* and the approving user. Single-use, 60 s TTL. |
| 223 |
* |
| 224 |
* @param array<string,string> $req Output of validate_authorize_request(). |
| 225 |
* @param int $user_id Approving admin user id. |
| 226 |
* @return string The authorization code. |
| 227 |
*/ |
| 228 |
public static function issue_code( array $req, int $user_id ): string { |
| 229 |
$code = bin2hex( random_bytes( 32 ) ); |
| 230 |
$state = self::state(); |
| 231 |
$state['codes'][ $code ] = array( |
| 232 |
'client_id' => $req['client_id'], |
| 233 |
'redirect_uri' => $req['redirect_uri'], |
| 234 |
'challenge' => $req['code_challenge'], |
| 235 |
'scope' => $req['scope'], |
| 236 |
'user_id' => $user_id, |
| 237 |
'expires' => time() + self::CODE_TTL, |
| 238 |
); |
| 239 |
self::save( $state ); |
| 240 |
return $code; |
| 241 |
} |
| 242 |
|
| 243 |
// -- Token endpoint -------------------------------------------------- |
| 244 |
|
| 245 |
/** |
| 246 |
* Exchange an authorization code (+ PKCE verifier) for tokens, or a |
| 247 |
* refresh token for a fresh access token. Returns the RFC 6749 token |
| 248 |
* response or a WP_Error whose data carries the OAuth error code. |
| 249 |
* |
| 250 |
* @param array<string,string> $body POST body params. |
| 251 |
* @return array<string,mixed>|\WP_Error |
| 252 |
*/ |
| 253 |
public static function exchange_token( array $body ) { |
| 254 |
$grant = isset( $body['grant_type'] ) ? (string) $body['grant_type'] : ''; |
| 255 |
|
| 256 |
if ( 'authorization_code' === $grant ) { |
| 257 |
return self::grant_authorization_code( $body ); |
| 258 |
} |
| 259 |
if ( 'refresh_token' === $grant ) { |
| 260 |
return self::grant_refresh_token( $body ); |
| 261 |
} |
| 262 |
return self::oauth_error( 'unsupported_grant_type', 'Unsupported grant_type.' ); |
| 263 |
} |
| 264 |
|
| 265 |
/** |
| 266 |
* authorization_code grant: verify the code + PKCE, mint tokens. |
| 267 |
* |
| 268 |
* @param array<string,string> $body POST body. |
| 269 |
* @return array<string,mixed>|\WP_Error |
| 270 |
*/ |
| 271 |
private static function grant_authorization_code( array $body ) { |
| 272 |
$code = isset( $body['code'] ) ? (string) $body['code'] : ''; |
| 273 |
$client_id = isset( $body['client_id'] ) ? (string) $body['client_id'] : ''; |
| 274 |
$redirect_uri = isset( $body['redirect_uri'] ) ? (string) $body['redirect_uri'] : ''; |
| 275 |
$verifier = isset( $body['code_verifier'] ) ? (string) $body['code_verifier'] : ''; |
| 276 |
|
| 277 |
$state = self::state(); |
| 278 |
if ( '' === $code || ! isset( $state['codes'][ $code ] ) ) { |
| 279 |
return self::oauth_error( 'invalid_grant', 'Unknown or expired authorization code.' ); |
| 280 |
} |
| 281 |
$entry = $state['codes'][ $code ]; |
| 282 |
|
| 283 |
// Single-use: remove immediately whether or not verification passes. |
| 284 |
unset( $state['codes'][ $code ] ); |
| 285 |
self::save( $state ); |
| 286 |
|
| 287 |
if ( $entry['expires'] < time() ) { |
| 288 |
return self::oauth_error( 'invalid_grant', 'Authorization code expired.' ); |
| 289 |
} |
| 290 |
if ( ! hash_equals( (string) $entry['client_id'], $client_id ) ) { |
| 291 |
return self::oauth_error( 'invalid_grant', 'client_id mismatch.' ); |
| 292 |
} |
| 293 |
if ( ! hash_equals( (string) $entry['redirect_uri'], $redirect_uri ) ) { |
| 294 |
return self::oauth_error( 'invalid_grant', 'redirect_uri mismatch.' ); |
| 295 |
} |
| 296 |
// PKCE S256: BASE64URL(SHA256(verifier)) must equal the stored challenge. |
| 297 |
if ( '' === $verifier || ! hash_equals( (string) $entry['challenge'], self::s256( $verifier ) ) ) { |
| 298 |
return self::oauth_error( 'invalid_grant', 'PKCE verification failed.' ); |
| 299 |
} |
| 300 |
|
| 301 |
return self::mint_tokens( $entry['client_id'], $entry['scope'], (int) $entry['user_id'] ); |
| 302 |
} |
| 303 |
|
| 304 |
/** |
| 305 |
* refresh_token grant: rotate the refresh token, issue a fresh access |
| 306 |
* token. The old refresh + its access token are revoked. |
| 307 |
* |
| 308 |
* @param array<string,string> $body POST body. |
| 309 |
* @return array<string,mixed>|\WP_Error |
| 310 |
*/ |
| 311 |
private static function grant_refresh_token( array $body ) { |
| 312 |
$refresh = isset( $body['refresh_token'] ) ? (string) $body['refresh_token'] : ''; |
| 313 |
$client_id = isset( $body['client_id'] ) ? (string) $body['client_id'] : ''; |
| 314 |
|
| 315 |
$state = self::state(); |
| 316 |
$rhash = self::hash( $refresh ); |
| 317 |
if ( '' === $refresh || ! isset( $state['refresh'][ $rhash ] ) ) { |
| 318 |
return self::oauth_error( 'invalid_grant', 'Unknown refresh token.' ); |
| 319 |
} |
| 320 |
$entry = $state['refresh'][ $rhash ]; |
| 321 |
if ( '' !== $client_id && ! hash_equals( (string) $entry['client_id'], $client_id ) ) { |
| 322 |
return self::oauth_error( 'invalid_grant', 'client_id mismatch.' ); |
| 323 |
} |
| 324 |
|
| 325 |
// Rotate: drop old refresh + its access token. |
| 326 |
unset( $state['refresh'][ $rhash ] ); |
| 327 |
if ( isset( $entry['access_hash'] ) ) { |
| 328 |
unset( $state['tokens'][ $entry['access_hash'] ] ); |
| 329 |
} |
| 330 |
self::save( $state ); |
| 331 |
|
| 332 |
return self::mint_tokens( $entry['client_id'], $entry['scope'], (int) $entry['user_id'] ); |
| 333 |
} |
| 334 |
|
| 335 |
/** |
| 336 |
* Mint an access + refresh token pair, store them hashed, and return |
| 337 |
* the RFC 6749 token response with the raw values. |
| 338 |
* |
| 339 |
* @param string $client_id Client id. |
| 340 |
* @param string $scope Granted scope string. |
| 341 |
* @param int $user_id Resource-owner user id. |
| 342 |
* @return array<string,mixed> |
| 343 |
*/ |
| 344 |
private static function mint_tokens( string $client_id, string $scope, int $user_id ): array { |
| 345 |
$access = bin2hex( random_bytes( 32 ) ); |
| 346 |
$refresh = bin2hex( random_bytes( 32 ) ); |
| 347 |
$ahash = self::hash( $access ); |
| 348 |
$rhash = self::hash( $refresh ); |
| 349 |
|
| 350 |
$state = self::state(); |
| 351 |
$state['tokens'][ $ahash ] = array( |
| 352 |
'client_id' => $client_id, |
| 353 |
'scope' => $scope, |
| 354 |
'user_id' => $user_id, |
| 355 |
'expires' => time() + self::ACCESS_TTL, |
| 356 |
'refresh' => $rhash, |
| 357 |
); |
| 358 |
$state['refresh'][ $rhash ] = array( |
| 359 |
'access_hash' => $ahash, |
| 360 |
'client_id' => $client_id, |
| 361 |
'scope' => $scope, |
| 362 |
'user_id' => $user_id, |
| 363 |
'expires' => time() + self::REFRESH_TTL, |
| 364 |
); |
| 365 |
self::save( $state ); |
| 366 |
|
| 367 |
return array( |
| 368 |
'access_token' => $access, |
| 369 |
'token_type' => 'Bearer', |
| 370 |
'expires_in' => self::ACCESS_TTL, |
| 371 |
'refresh_token' => $refresh, |
| 372 |
'scope' => $scope, |
| 373 |
); |
| 374 |
} |
| 375 |
|
| 376 |
// -- Access-token validation (called by Mcp_Server) ------------------ |
| 377 |
|
| 378 |
/** |
| 379 |
* Validate a bearer access token presented to the MCP endpoint. |
| 380 |
* Returns the token's grant record (scope, user_id, client_id) when |
| 381 |
* valid + unexpired, or null. Constant-time via hashed lookup. |
| 382 |
* |
| 383 |
* @param string $token Raw access token from the Authorization header. |
| 384 |
* @return array{client_id:string,scope:string,user_id:int}|null |
| 385 |
*/ |
| 386 |
public static function validate_token( string $token ): ?array { |
| 387 |
if ( '' === $token ) { |
| 388 |
return null; |
| 389 |
} |
| 390 |
$state = self::state(); |
| 391 |
$hash = self::hash( $token ); |
| 392 |
if ( ! isset( $state['tokens'][ $hash ] ) ) { |
| 393 |
return null; |
| 394 |
} |
| 395 |
$entry = $state['tokens'][ $hash ]; |
| 396 |
if ( (int) $entry['expires'] < time() ) { |
| 397 |
return null; |
| 398 |
} |
| 399 |
return array( |
| 400 |
'client_id' => (string) $entry['client_id'], |
| 401 |
'scope' => (string) $entry['scope'], |
| 402 |
'user_id' => (int) $entry['user_id'], |
| 403 |
); |
| 404 |
} |
| 405 |
|
| 406 |
/** |
| 407 |
* Whether a granted scope string is read-only. `mcp` is the umbrella |
| 408 |
* scope that grants read+write (matching a default pairing token), so |
| 409 |
* only a grant that carries NEITHER `write` NOR `mcp` -- i.e. `read` |
| 410 |
* alone -- is read-only. |
| 411 |
*/ |
| 412 |
public static function scope_is_read_only( string $scope ): bool { |
| 413 |
$parts = preg_split( '/\s+/', trim( $scope ) ) ?: array(); |
| 414 |
return ! in_array( 'write', $parts, true ) && ! in_array( 'mcp', $parts, true ); |
| 415 |
} |
| 416 |
|
| 417 |
/** Revoke every OAuth token + client (used by disconnect). */ |
| 418 |
public static function revoke_all(): void { |
| 419 |
delete_option( self::OPTION ); |
| 420 |
} |
| 421 |
|
| 422 |
// -- State + helpers ------------------------------------------------- |
| 423 |
|
| 424 |
/** |
| 425 |
* Load state with defaults, pruning expired codes/tokens/refresh |
| 426 |
* entries on the way out so the option can't grow unbounded. |
| 427 |
* |
| 428 |
* @return array<string,array<string,mixed>> |
| 429 |
*/ |
| 430 |
private static function state(): array { |
| 431 |
$stored = get_option( self::OPTION, array() ); |
| 432 |
if ( ! is_array( $stored ) ) { |
| 433 |
$stored = array(); |
| 434 |
} |
| 435 |
$state = array( |
| 436 |
'clients' => isset( $stored['clients'] ) && is_array( $stored['clients'] ) ? $stored['clients'] : array(), |
| 437 |
'codes' => isset( $stored['codes'] ) && is_array( $stored['codes'] ) ? $stored['codes'] : array(), |
| 438 |
'tokens' => isset( $stored['tokens'] ) && is_array( $stored['tokens'] ) ? $stored['tokens'] : array(), |
| 439 |
'refresh' => isset( $stored['refresh'] ) && is_array( $stored['refresh'] ) ? $stored['refresh'] : array(), |
| 440 |
); |
| 441 |
|
| 442 |
$now = time(); |
| 443 |
foreach ( $state['codes'] as $k => $v ) { |
| 444 |
if ( ! isset( $v['expires'] ) || $v['expires'] < $now ) { |
| 445 |
unset( $state['codes'][ $k ] ); |
| 446 |
} |
| 447 |
} |
| 448 |
foreach ( $state['tokens'] as $k => $v ) { |
| 449 |
if ( ! isset( $v['expires'] ) || $v['expires'] < $now ) { |
| 450 |
unset( $state['tokens'][ $k ] ); |
| 451 |
} |
| 452 |
} |
| 453 |
foreach ( $state['refresh'] as $k => $v ) { |
| 454 |
if ( isset( $v['expires'] ) && $v['expires'] < $now ) { |
| 455 |
unset( $state['refresh'][ $k ] ); |
| 456 |
} |
| 457 |
} |
| 458 |
return $state; |
| 459 |
} |
| 460 |
|
| 461 |
/** Persist state (autoload off -- this is a hot-write, request-scoped option). */ |
| 462 |
private static function save( array $state ): void { |
| 463 |
update_option( self::OPTION, $state, false ); |
| 464 |
} |
| 465 |
|
| 466 |
/** |
| 467 |
* Look up a registered client. |
| 468 |
* |
| 469 |
* @param string $client_id Client id. |
| 470 |
* @return array{redirect_uris:string[],name:string,created:int}|null |
| 471 |
*/ |
| 472 |
private static function client( string $client_id ): ?array { |
| 473 |
if ( '' === $client_id ) { |
| 474 |
return null; |
| 475 |
} |
| 476 |
$clients = self::state()['clients']; |
| 477 |
if ( ! isset( $clients[ $client_id ] ) || ! is_array( $clients[ $client_id ] ) ) { |
| 478 |
return null; |
| 479 |
} |
| 480 |
$c = $clients[ $client_id ]; |
| 481 |
return array( |
| 482 |
'redirect_uris' => isset( $c['redirect_uris'] ) && is_array( $c['redirect_uris'] ) ? array_map( 'strval', $c['redirect_uris'] ) : array(), |
| 483 |
'name' => isset( $c['name'] ) ? (string) $c['name'] : 'MCP Client', |
| 484 |
'created' => isset( $c['created'] ) ? (int) $c['created'] : 0, |
| 485 |
); |
| 486 |
} |
| 487 |
|
| 488 |
/** SHA-256 hash used to store tokens at rest. */ |
| 489 |
private static function hash( string $value ): string { |
| 490 |
return hash( 'sha256', $value ); |
| 491 |
} |
| 492 |
|
| 493 |
/** BASE64URL(SHA256(verifier)) -- the PKCE S256 transformation. */ |
| 494 |
private static function s256( string $verifier ): string { |
| 495 |
return rtrim( strtr( base64_encode( hash( 'sha256', $verifier, true ) ), '+/', '-_' ), '=' ); |
| 496 |
} |
| 497 |
|
| 498 |
/** |
| 499 |
* Constrain a requested scope to what we support. Defaults to `mcp` |
| 500 |
* (read+write umbrella). An explicit `mcp:read` / `read`-only request |
| 501 |
* yields a read-only grant. |
| 502 |
*/ |
| 503 |
private static function normalize_scope( string $requested ): string { |
| 504 |
$parts = preg_split( '/\s+/', trim( $requested ) ) ?: array(); |
| 505 |
$parts = array_values( array_intersect( $parts, self::SUPPORTED_SCOPES ) ); |
| 506 |
if ( empty( $parts ) ) { |
| 507 |
return 'mcp'; |
| 508 |
} |
| 509 |
return implode( ' ', $parts ); |
| 510 |
} |
| 511 |
|
| 512 |
/** Whether a redirect_uri is structurally acceptable (http(s) or a custom scheme). */ |
| 513 |
private static function is_valid_redirect_uri( string $uri ): bool { |
| 514 |
$uri = trim( $uri ); |
| 515 |
if ( '' === $uri ) { |
| 516 |
return false; |
| 517 |
} |
| 518 |
// Allow standard web redirect URIs and native-client custom schemes. |
| 519 |
return (bool) preg_match( '#^[a-zA-Z][a-zA-Z0-9+.\-]*://#', $uri ); |
| 520 |
} |
| 521 |
|
| 522 |
/** |
| 523 |
* Build a WP_Error whose data carries an OAuth 2.0 `error` code so the |
| 524 |
* token route can render the RFC 6749 error body. |
| 525 |
* |
| 526 |
* @param string $code OAuth error code (invalid_grant, ...). |
| 527 |
* @param string $message Human-readable description. |
| 528 |
* @return \WP_Error |
| 529 |
*/ |
| 530 |
private static function oauth_error( string $code, string $message ): \WP_Error { |
| 531 |
return new \WP_Error( |
| 532 |
$code, |
| 533 |
$message, |
| 534 |
array( |
| 535 |
'status' => 400, |
| 536 |
'error' => $code, |
| 537 |
'error_description' => $message, |
| 538 |
) |
| 539 |
); |
| 540 |
} |
| 541 |
} |
| 542 |
|
