| @@ -6,8 +6,12 @@ | ||
| 6 | 6 | */ |
| 7 | 7 | |
| 8 | 8 | namespace Activitypub\Rest; |
| 9 | 9 | |
| 10 | +use Activitypub\Signature; | |
| 11 | + | |
| 12 | +use function Activitypub\use_authorized_fetch; | |
| 13 | + | |
| 10 | 14 | /** |
| 11 | 15 | * ActivityPub Server REST-Class. |
| 12 | 16 | * |
| 13 | 17 | * @author Django Doucet |
| @@ -22,12 +26,64 @@ | ||
| 22 | 26 | \add_filter( 'rest_request_before_callbacks', array( self::class, 'validate_requests' ), 9, 3 ); |
| 23 | 27 | \add_filter( 'rest_request_parameter_order', array( self::class, 'request_parameter_order' ), 10, 2 ); |
| 24 | 28 | |
| 25 | 29 | \add_filter( 'rest_post_dispatch', array( self::class, 'filter_output' ), 10, 3 ); |
| 26 | - \add_filter( 'rest_post_dispatch', array( self::class, 'add_cors_headers' ), 10, 3 ); | |
| 27 | 30 | } |
| 28 | 31 | |
| 29 | 32 | /** |
| 33 | + * Callback function to authorize an api request. | |
| 34 | + * | |
| 35 | + * The function is meant to be used as part of permission callbacks for rest api endpoints. | |
| 36 | + * | |
| 37 | + * It verifies the signature of POST, PUT, PATCH, and DELETE requests, as well as GET requests in secure mode. | |
| 38 | + * You can use the filter 'activitypub_defer_signature_verification' to defer the signature verification. | |
| 39 | + * HEAD requests are always bypassed. | |
| 40 | + * | |
| 41 | + * @see https://www.w3.org/wiki/SocialCG/ActivityPub/Primer/Authentication_Authorization#Authorized_fetch | |
| 42 | + * @see https://swicg.github.io/activitypub-http-signature/#authorized-fetch | |
| 43 | + * | |
| 44 | + * @param \WP_REST_Request $request The request object. | |
| 45 | + * | |
| 46 | + * @return bool|\WP_Error True if the request is authorized, WP_Error if not. | |
| 47 | + */ | |
| 48 | + public static function verify_signature( $request ) { | |
| 49 | + if ( 'HEAD' === $request->get_method() ) { | |
| 50 | + return true; | |
| 51 | + } | |
| 52 | + | |
| 53 | + /** | |
| 54 | + * Filter to defer signature verification. | |
| 55 | + * | |
| 56 | + * Skip signature verification for debugging purposes or to reduce load for | |
| 57 | + * certain Activity-Types, like "Delete". | |
| 58 | + * | |
| 59 | + * @param bool $defer Whether to defer signature verification. | |
| 60 | + * @param \WP_REST_Request $request The request used to generate the response. | |
| 61 | + * | |
| 62 | + * @return bool Whether to defer signature verification. | |
| 63 | + */ | |
| 64 | + $defer = \apply_filters( 'activitypub_defer_signature_verification', false, $request ); | |
| 65 | + | |
| 66 | + if ( $defer ) { | |
| 67 | + return true; | |
| 68 | + } | |
| 69 | + | |
| 70 | + // POST-Requests always have to be signed, GET-Requests only require a signature in secure mode. | |
| 71 | + if ( 'GET' !== $request->get_method() || use_authorized_fetch() ) { | |
| 72 | + $verified_request = Signature::verify_http_signature( $request ); | |
| 73 | + if ( \is_wp_error( $verified_request ) ) { | |
| 74 | + return new \WP_Error( | |
| 75 | + 'activitypub_signature_verification', | |
| 76 | + $verified_request->get_error_message(), | |
| 77 | + array( 'status' => 401 ) | |
| 78 | + ); | |
| 79 | + } | |
| 80 | + } | |
| 81 | + | |
| 82 | + return true; | |
| 83 | + } | |
| 84 | + | |
| 85 | + /** | |
| 30 | 86 | * Callback function to validate incoming ActivityPub requests |
| 31 | 87 | * |
| 32 | 88 | * @param \WP_REST_Response|\WP_HTTP_Response|\WP_Error|mixed $response Result to send to the client. |
| 33 | 89 | * Usually a WP_REST_Response or WP_Error. |
| @@ -121,13 +177,8 @@ | ||
| 121 | 177 | if ( ! \str_starts_with( $route, '/' . ACTIVITYPUB_REST_NAMESPACE ) ) { |
| 122 | 178 | return $response; |
| 123 | 179 | } |
| 124 | 180 | |
| 125 | - // Exclude OAuth endpoints - they have their own error format per RFC 6749. | |
| 126 | - if ( \str_starts_with( $route, '/' . ACTIVITYPUB_REST_NAMESPACE . '/oauth' ) ) { | |
| 127 | - return $response; | |
| 128 | - } | |
| 129 | - | |
| 130 | 181 | // Only alter responses that return an error status code. |
| 131 | 182 | if ( $response->get_status() < 400 ) { |
| 132 | 183 | return $response; |
| 133 | 184 | } |
| @@ -156,53 +207,6 @@ | ||
| 156 | 207 | |
| 157 | 208 | $response->set_data( $error ); |
| 158 | 209 | |
| 159 | 210 | return $response; |
| 160 | - } | |
| 161 | - | |
| 162 | - /** | |
| 163 | - * Add CORS headers to ActivityPub REST responses. | |
| 164 | - * | |
| 165 | - * @param \WP_REST_Response $response The REST response. | |
| 166 | - * @param \WP_REST_Server $server The REST server instance. | |
| 167 | - * @param \WP_REST_Request $request The request object. | |
| 168 | - * | |
| 169 | - * @return \WP_REST_Response The modified response. | |
| 170 | - */ | |
| 171 | - public static function add_cors_headers( $response, $server, $request ) { | |
| 172 | - $route = $request->get_route(); | |
| 173 | - $namespace = '/' . ACTIVITYPUB_REST_NAMESPACE; | |
| 174 | - | |
| 175 | - // Only add CORS to ActivityPub endpoints, except the interactive OAuth authorize endpoint. | |
| 176 | - if ( ! \str_starts_with( $route, $namespace ) || \str_starts_with( $route, $namespace . '/oauth/authorize' ) ) { | |
| 177 | - return $response; | |
| 178 | - } | |
| 179 | - | |
| 180 | - /* | |
| 181 | - * ActivityPub data is meant to be publicly readable by federation peers | |
| 182 | - * and browser-side clients. We do not enable credentialed cross-origin | |
| 183 | - * access: cookie auth would still be rejected by WordPress core's | |
| 184 | - * REST nonce check, and OAuth Bearer tokens travel in the | |
| 185 | - * Authorization header — which is permitted via Allow-Headers and | |
| 186 | - * does not require Allow-Credentials. | |
| 187 | - */ | |
| 188 | - $response->header( 'Access-Control-Allow-Origin', '*' ); | |
| 189 | - $response->header( 'Access-Control-Allow-Methods', 'GET, POST, OPTIONS' ); | |
| 190 | - $response->header( 'Access-Control-Allow-Headers', 'Accept, Content-Type, Authorization, Last-Event-ID' ); | |
| 191 | - | |
| 192 | - return $response; | |
| 193 | - } | |
| 194 | - | |
| 195 | - /** | |
| 196 | - * Send CORS headers directly via header(). | |
| 197 | - * | |
| 198 | - * Use this for endpoints that bypass the REST response flow | |
| 199 | - * (e.g. SSE streams that call exit() instead of returning a WP_REST_Response). | |
| 200 | - * | |
| 201 | - * @since 8.1.0 | |
| 202 | - */ | |
| 203 | - public static function send_cors_headers() { | |
| 204 | - \header( 'Access-Control-Allow-Origin: *' ); | |
| 205 | - \header( 'Access-Control-Allow-Methods: GET, POST, OPTIONS' ); | |
| 206 | - \header( 'Access-Control-Allow-Headers: Accept, Content-Type, Authorization, Last-Event-ID' ); | |
| 207 | 211 | } |
| 208 | 212 | } |