| @@ -1,15 +1,20 @@ | ||
| 1 | 1 | <?php |
| 2 | +/** | |
| 3 | + * Signature class file. | |
| 4 | + * | |
| 5 | + * @package Activitypub | |
| 6 | + */ | |
| 7 | + | |
| 2 | 8 | namespace Activitypub; |
| 3 | 9 | |
| 4 | -use WP_Error; | |
| 5 | -use DateTime; | |
| 6 | -use DateTimeZone; | |
| 7 | -use WP_REST_Request; | |
| 8 | -use Activitypub\Collection\Users; | |
| 10 | +use Activitypub\Collection\Actors; | |
| 11 | +use Activitypub\Collection\Remote_Actors; | |
| 12 | +use Activitypub\Signature\Http_Message_Signature; | |
| 13 | +use Activitypub\Signature\Http_Signature_Draft; | |
| 9 | 14 | |
| 10 | 15 | /** |
| 11 | - * ActivityPub Signature Class | |
| 16 | + * ActivityPub Signature Class. | |
| 12 | 17 | * |
| 13 | 18 | * @author Matthias Pfefferle |
| 14 | 19 | * @author Django Doucet |
| 15 | 20 | */ |
| @@ -15,191 +20,266 @@ | ||
| 15 | 20 | */ |
| 16 | 21 | class Signature { |
| 17 | 22 | |
| 18 | 23 | /** |
| 19 | - * Return the public key for a given user. | |
| 24 | + * Initialize the class. | |
| 25 | + */ | |
| 26 | + public static function init() { | |
| 27 | + \add_filter( 'http_request_args', array( self::class, 'sign_request' ), 0, 2 ); // Ahead of all other filters, so signature is set. | |
| 28 | + \add_filter( 'http_response', array( self::class, 'maybe_double_knock' ), 10, 3 ); | |
| 29 | + } | |
| 30 | + | |
| 31 | + /** | |
| 32 | + * Sign an HTTP Request. | |
| 20 | 33 | * |
| 21 | - * @param int $user_id The WordPress User ID. | |
| 22 | - * @param bool $force Force the generation of a new key pair. | |
| 34 | + * @param array $args An array of HTTP request arguments. | |
| 35 | + * @param string $url The request URL. | |
| 23 | 36 | * |
| 24 | - * @return mixed The public key. | |
| 37 | + * @return array Request arguments with signature headers. | |
| 25 | 38 | */ |
| 26 | - public static function get_public_key_for( $user_id, $force = false ) { | |
| 27 | - if ( $force ) { | |
| 28 | - self::generate_key_pair_for( $user_id ); | |
| 39 | + public static function sign_request( $args, $url ) { | |
| 40 | + // Bail if there's nothing to sign with. | |
| 41 | + if ( ! isset( $args['key_id'], $args['private_key'] ) ) { | |
| 42 | + return $args; | |
| 29 | 43 | } |
| 30 | 44 | |
| 31 | - $key_pair = self::get_keypair_for( $user_id ); | |
| 45 | + if ( '1' === \get_option( 'activitypub_rfc9421_signature' ) && self::could_support_rfc9421( $url ) ) { | |
| 46 | + $signature = new Http_Message_Signature(); | |
| 47 | + } else { | |
| 48 | + $signature = new Http_Signature_Draft(); | |
| 49 | + } | |
| 32 | 50 | |
| 33 | - return $key_pair['public_key']; | |
| 51 | + return $signature->sign( $args, $url ); | |
| 34 | 52 | } |
| 35 | 53 | |
| 36 | 54 | /** |
| 37 | - * Return the private key for a given user. | |
| 55 | + * Verifies the http signatures | |
| 38 | 56 | * |
| 39 | - * @param int $user_id The WordPress User ID. | |
| 40 | - * @param bool $force Force the generation of a new key pair. | |
| 57 | + * @param \WP_REST_Request|array $request The request object or $_SERVER array. | |
| 41 | 58 | * |
| 42 | - * @return mixed The private key. | |
| 59 | + * @return bool|\WP_Error A boolean or WP_Error. | |
| 43 | 60 | */ |
| 44 | - public static function get_private_key_for( $user_id, $force = false ) { | |
| 45 | - if ( $force ) { | |
| 46 | - self::generate_key_pair_for( $user_id ); | |
| 61 | + public static function verify_http_signature( $request ) { | |
| 62 | + if ( is_object( $request ) ) { // REST Request object. | |
| 63 | + $body = $request->get_body(); | |
| 64 | + $headers = $request->get_headers(); | |
| 65 | + $headers['(request-target)'][0] = strtolower( $request->get_method() ) . ' ' . self::get_route( $request ); | |
| 66 | + } else { | |
| 67 | + $headers = self::format_server_request( $request ); | |
| 68 | + $headers['(request-target)'][0] = strtolower( $headers['request_method'][0] ) . ' ' . $headers['request_uri'][0]; | |
| 47 | 69 | } |
| 48 | 70 | |
| 49 | - $key_pair = self::get_keypair_for( $user_id ); | |
| 71 | + $signature = isset( $headers['signature_input'] ) ? new Http_Message_Signature() : new Http_Signature_Draft(); | |
| 50 | 72 | |
| 51 | - return $key_pair['private_key']; | |
| 73 | + return $signature->verify( $headers, $body ?? null ); | |
| 52 | 74 | } |
| 53 | 75 | |
| 54 | 76 | /** |
| 55 | - * Return the key pair for a given user. | |
| 77 | + * If a request with RFC-9421 signature fails, we try again with the Draft Cavage signature. | |
| 56 | 78 | * |
| 57 | - * @param int $user_id The WordPress User ID. | |
| 79 | + * @param array $response HTTP response. | |
| 80 | + * @param array $args HTTP request arguments. | |
| 81 | + * @param string $url The request URL. | |
| 58 | 82 | * |
| 59 | - * @return array The key pair. | |
| 83 | + * @return array The HTTP response. | |
| 60 | 84 | */ |
| 61 | - public static function get_keypair_for( $user_id ) { | |
| 62 | - $option_key = self::get_signature_options_key_for( $user_id ); | |
| 63 | - $key_pair = \get_option( $option_key ); | |
| 85 | + public static function maybe_double_knock( $response, $args, $url ) { | |
| 86 | + // Bail if it didn't use an RFC-9421 signature or there's nothing to sign with. | |
| 87 | + if ( ! isset( $args['key_id'], $args['private_key'], $args['headers']['Signature-Input'] ) ) { | |
| 88 | + return $response; | |
| 89 | + } | |
| 64 | 90 | |
| 65 | - if ( ! $key_pair ) { | |
| 66 | - $key_pair = self::generate_key_pair_for( $user_id ); | |
| 91 | + $response_code = \wp_remote_retrieve_response_code( $response ); | |
| 92 | + | |
| 93 | + // Fall back to Draft Cavage signature for any 4xx responses. | |
| 94 | + if ( $response_code >= 400 && $response_code < 500 ) { | |
| 95 | + unset( $args['headers']['Signature'], $args['headers']['Signature-Input'], $args['headers']['Content-Digest'] ); | |
| 96 | + self::rfc9421_add_unsupported_host( $url ); | |
| 97 | + | |
| 98 | + $args = ( new Http_Signature_Draft() )->sign( $args, $url ); | |
| 99 | + $response = \wp_remote_request( $url, $args ); | |
| 67 | 100 | } |
| 68 | 101 | |
| 69 | - return $key_pair; | |
| 102 | + return $response; | |
| 70 | 103 | } |
| 71 | 104 | |
| 72 | 105 | /** |
| 73 | - * Generates the pair keys | |
| 106 | + * Formats the $_SERVER to resemble the WP_REST_REQUEST array, | |
| 107 | + * for use with verify_http_signature(). | |
| 74 | 108 | * |
| 75 | - * @param int $user_id The WordPress User ID. | |
| 109 | + * @param array $server The $_SERVER array. | |
| 76 | 110 | * |
| 77 | - * @return array The key pair. | |
| 111 | + * @return array $request The formatted request array. | |
| 78 | 112 | */ |
| 79 | - protected static function generate_key_pair_for( $user_id ) { | |
| 80 | - $option_key = self::get_signature_options_key_for( $user_id ); | |
| 81 | - $key_pair = self::check_legacy_key_pair_for( $user_id ); | |
| 113 | + public static function format_server_request( $server ) { | |
| 114 | + $headers = array(); | |
| 82 | 115 | |
| 83 | - if ( $key_pair ) { | |
| 84 | - \add_option( $option_key, $key_pair ); | |
| 116 | + foreach ( $server as $key => $value ) { | |
| 117 | + $key = \str_replace( 'http_', '', \strtolower( $key ) ); | |
| 118 | + $headers[ $key ][] = \wp_unslash( $value ); | |
| 85 | 119 | |
| 86 | - return $key_pair; | |
| 87 | 120 | } |
| 88 | 121 | |
| 89 | - $config = array( | |
| 90 | - 'digest_alg' => 'sha512', | |
| 91 | - 'private_key_bits' => 2048, | |
| 92 | - 'private_key_type' => \OPENSSL_KEYTYPE_RSA, | |
| 93 | - ); | |
| 122 | + return $headers; | |
| 123 | + } | |
| 94 | 124 | |
| 95 | - $key = \openssl_pkey_new( $config ); | |
| 96 | - $priv_key = null; | |
| 125 | + /** | |
| 126 | + * Returns route. | |
| 127 | + * | |
| 128 | + * @param \WP_REST_Request $request The request object. | |
| 129 | + * | |
| 130 | + * @return string | |
| 131 | + */ | |
| 132 | + private static function get_route( $request ) { | |
| 133 | + // Check if the route starts with "index.php". | |
| 134 | + if ( str_starts_with( $request->get_route(), '/index.php' ) || ! rest_get_url_prefix() ) { | |
| 135 | + $route = $request->get_route(); | |
| 136 | + } else { | |
| 137 | + $route = '/' . rest_get_url_prefix() . '/' . ltrim( $request->get_route(), '/' ); | |
| 138 | + } | |
| 97 | 139 | |
| 98 | - \openssl_pkey_export( $key, $priv_key ); | |
| 140 | + // Fix route for subdirectory installations. | |
| 141 | + $path = \wp_parse_url( \get_home_url(), PHP_URL_PATH ); | |
| 99 | 142 | |
| 100 | - $detail = \openssl_pkey_get_details( $key ); | |
| 143 | + if ( \is_string( $path ) ) { | |
| 144 | + $path = trim( $path, '/' ); | |
| 145 | + } | |
| 101 | 146 | |
| 102 | - // check if keys are valid | |
| 103 | - if ( | |
| 104 | - empty( $priv_key ) || ! is_string( $priv_key ) || | |
| 105 | - ! isset( $detail['key'] ) || ! is_string( $detail['key'] ) | |
| 106 | - ) { | |
| 107 | - return array( | |
| 108 | - 'private_key' => null, | |
| 109 | - 'public_key' => null, | |
| 110 | - ); | |
| 147 | + if ( $path ) { | |
| 148 | + $route = '/' . $path . $route; | |
| 111 | 149 | } |
| 112 | 150 | |
| 113 | - $key_pair = array( | |
| 114 | - 'private_key' => $priv_key, | |
| 115 | - 'public_key' => $detail['key'], | |
| 116 | - ); | |
| 151 | + return $route; | |
| 152 | + } | |
| 117 | 153 | |
| 118 | - // persist keys | |
| 119 | - \add_option( $option_key, $key_pair ); | |
| 154 | + /** | |
| 155 | + * Check if RFC-9421 signature could be supported. | |
| 156 | + * | |
| 157 | + * @param string $url The URL to check. | |
| 158 | + * | |
| 159 | + * @return bool True, if RFC-9421 signature could be supported, false otherwise. | |
| 160 | + */ | |
| 161 | + private static function could_support_rfc9421( $url ) { | |
| 162 | + $host = \wp_parse_url( $url, \PHP_URL_HOST ); | |
| 163 | + $list = \get_option( 'activitypub_rfc9421_unsupported', array() ); | |
| 120 | 164 | |
| 121 | - return $key_pair; | |
| 165 | + if ( isset( $list[ $host ] ) ) { | |
| 166 | + if ( $list[ $host ] > \time() ) { | |
| 167 | + return false; | |
| 168 | + } | |
| 169 | + | |
| 170 | + unset( $list[ $host ] ); | |
| 171 | + \update_option( 'activitypub_rfc9421_unsupported', $list ); | |
| 172 | + } | |
| 173 | + | |
| 174 | + return true; | |
| 122 | 175 | } |
| 123 | 176 | |
| 124 | 177 | /** |
| 125 | - * Return the option key for a given user. | |
| 178 | + * Set RFC-9421 signature unsupported for a given host. | |
| 126 | 179 | * |
| 127 | - * @param int $user_id The WordPress User ID. | |
| 180 | + * @param string $url The URL to set. | |
| 181 | + */ | |
| 182 | + private static function rfc9421_add_unsupported_host( $url ) { | |
| 183 | + $list = \get_option( 'activitypub_rfc9421_unsupported', array() ); | |
| 184 | + $host = \wp_parse_url( $url, \PHP_URL_HOST ); | |
| 185 | + | |
| 186 | + $list[ $host ] = \time() + MONTH_IN_SECONDS; | |
| 187 | + \update_option( 'activitypub_rfc9421_unsupported', $list, false ); | |
| 188 | + } | |
| 189 | + | |
| 190 | + /** | |
| 191 | + * Return the public key for a given user. | |
| 128 | 192 | * |
| 129 | - * @return string The option key. | |
| 193 | + * @deprecated 7.0.0 Use {@see Actors::get_public_key()}. | |
| 194 | + * | |
| 195 | + * @param int $user_id The WordPress User ID. | |
| 196 | + * @param bool $force Optional. Force the generation of a new key pair. Default false. | |
| 197 | + * | |
| 198 | + * @return string The public key. | |
| 130 | 199 | */ |
| 131 | - protected static function get_signature_options_key_for( $user_id ) { | |
| 132 | - $id = $user_id; | |
| 200 | + public static function get_public_key_for( $user_id, $force = false ) { | |
| 201 | + \_deprecated_function( __METHOD__, '7.0.0', 'Activitypub\Collection\Actors::get_public_key' ); | |
| 133 | 202 | |
| 134 | - if ( $user_id > 0 ) { | |
| 135 | - $user = \get_userdata( $user_id ); | |
| 136 | - // sanatize username because it could include spaces and special chars | |
| 137 | - $id = sanitize_title( $user->user_login ); | |
| 138 | - } | |
| 203 | + return Actors::get_public_key( $user_id, $force ); | |
| 204 | + } | |
| 139 | 205 | |
| 140 | - return 'activitypub_keypair_for_' . $id; | |
| 206 | + /** | |
| 207 | + * Return the private key for a given user. | |
| 208 | + * | |
| 209 | + * @deprecated 7.0.0 Use {@see Actors::get_private_key()}. | |
| 210 | + * | |
| 211 | + * @param int $user_id The WordPress User ID. | |
| 212 | + * @param bool $force Optional. Force the generation of a new key pair. Default false. | |
| 213 | + * | |
| 214 | + * @return string The private key. | |
| 215 | + */ | |
| 216 | + public static function get_private_key_for( $user_id, $force = false ) { | |
| 217 | + \_deprecated_function( __METHOD__, '7.0.0', 'Activitypub\Collection\Actors::get_private_key' ); | |
| 218 | + | |
| 219 | + return Actors::get_private_key( $user_id, $force ); | |
| 141 | 220 | } |
| 142 | 221 | |
| 143 | 222 | /** |
| 144 | - * Check if there is a legacy key pair | |
| 223 | + * Return the key pair for a given user. | |
| 145 | 224 | * |
| 225 | + * @deprecated 7.0.0 Use {@see Actors::get_keypair()}. | |
| 226 | + * | |
| 146 | 227 | * @param int $user_id The WordPress User ID. |
| 147 | 228 | * |
| 148 | - * @return array|bool The key pair or false. | |
| 229 | + * @return array The key pair. | |
| 149 | 230 | */ |
| 150 | - protected static function check_legacy_key_pair_for( $user_id ) { | |
| 151 | - switch ( $user_id ) { | |
| 152 | - case 0: | |
| 153 | - $public_key = \get_option( 'activitypub_blog_user_public_key' ); | |
| 154 | - $private_key = \get_option( 'activitypub_blog_user_private_key' ); | |
| 155 | - break; | |
| 156 | - case -1: | |
| 157 | - $public_key = \get_option( 'activitypub_application_user_public_key' ); | |
| 158 | - $private_key = \get_option( 'activitypub_application_user_private_key' ); | |
| 159 | - break; | |
| 160 | - default: | |
| 161 | - $public_key = \get_user_meta( $user_id, 'magic_sig_public_key', true ); | |
| 162 | - $private_key = \get_user_meta( $user_id, 'magic_sig_private_key', true ); | |
| 163 | - break; | |
| 164 | - } | |
| 231 | + public static function get_keypair_for( $user_id ) { | |
| 232 | + \_deprecated_function( __METHOD__, '7.0.0', 'Activitypub\Collection\Actors::get_keypair' ); | |
| 165 | 233 | |
| 166 | - if ( ! empty( $public_key ) && is_string( $public_key ) && ! empty( $private_key ) && is_string( $private_key ) ) { | |
| 167 | - return array( | |
| 168 | - 'private_key' => $private_key, | |
| 169 | - 'public_key' => $public_key, | |
| 170 | - ); | |
| 171 | - } | |
| 234 | + return Actors::get_keypair( $user_id ); | |
| 235 | + } | |
| 172 | 236 | |
| 173 | - return false; | |
| 237 | + /** | |
| 238 | + * Get public key from key_id. | |
| 239 | + * | |
| 240 | + * @deprecated 7.4.0 Use {@see Remote_Actors::get_public_key()}. | |
| 241 | + * | |
| 242 | + * @param string $key_id The URL to the public key. | |
| 243 | + * | |
| 244 | + * @return resource|\WP_Error The public key resource or WP_Error. | |
| 245 | + */ | |
| 246 | + public static function get_remote_key( $key_id ) { | |
| 247 | + \_deprecated_function( __METHOD__, '7.4.0', 'Activitypub\Collection\Remote_Actors::get_public_key()' ); | |
| 248 | + | |
| 249 | + return Remote_Actors::get_public_key( $key_id ); | |
| 174 | 250 | } |
| 175 | 251 | |
| 176 | 252 | /** |
| 177 | - * Generates the Signature for a HTTP Request | |
| 253 | + * Generates the Signature for an HTTP Request. | |
| 178 | 254 | * |
| 255 | + * @deprecated 7.0.0 Use {@see Signature::sign_request()}. | |
| 256 | + * | |
| 179 | 257 | * @param int $user_id The WordPress User ID. |
| 180 | 258 | * @param string $http_method The HTTP method. |
| 181 | 259 | * @param string $url The URL to send the request to. |
| 182 | 260 | * @param string $date The date the request is sent. |
| 183 | - * @param string $digest The digest of the request body. | |
| 261 | + * @param string $digest Optional. The digest of the request body. Default null. | |
| 184 | 262 | * |
| 185 | 263 | * @return string The signature. |
| 186 | 264 | */ |
| 187 | 265 | public static function generate_signature( $user_id, $http_method, $url, $date, $digest = null ) { |
| 188 | - $user = Users::get_by_id( $user_id ); | |
| 189 | - $key = self::get_private_key_for( $user->get__id() ); | |
| 266 | + \_deprecated_function( __METHOD__, '7.0.0', self::class . '::sign_request()' ); | |
| 190 | 267 | |
| 268 | + $user = Actors::get_by_id( $user_id ); | |
| 269 | + $key = Actors::get_private_key( $user_id ); | |
| 270 | + | |
| 191 | 271 | $url_parts = \wp_parse_url( $url ); |
| 192 | 272 | |
| 193 | 273 | $host = $url_parts['host']; |
| 194 | 274 | $path = '/'; |
| 195 | 275 | |
| 196 | - // add path | |
| 276 | + // Add path. | |
| 197 | 277 | if ( ! empty( $url_parts['path'] ) ) { |
| 198 | 278 | $path = $url_parts['path']; |
| 199 | 279 | } |
| 200 | 280 | |
| 201 | - // add query | |
| 281 | + // Add query. | |
| 202 | 282 | if ( ! empty( $url_parts['query'] ) ) { |
| 203 | 283 | $path .= '?' . $url_parts['query']; |
| 204 | 284 | } |
| 205 | 285 | |
| @@ -212,11 +292,11 @@ | ||
| 212 | 292 | } |
| 213 | 293 | |
| 214 | 294 | $signature = null; |
| 215 | 295 | \openssl_sign( $signed_string, $signature, $key, \OPENSSL_ALGO_SHA256 ); |
| 216 | - $signature = \base64_encode( $signature ); // phpcs:ignore | |
| 296 | + $signature = \base64_encode( $signature ); // phpcs:ignore WordPress.PHP.DiscouragedPHPFunctions.obfuscation_base64_encode | |
| 217 | 297 | |
| 218 | - $key_id = $user->get_url() . '#main-key'; | |
| 298 | + $key_id = $user->get_id() . '#main-key'; | |
| 219 | 299 | |
| 220 | 300 | if ( ! empty( $digest ) ) { |
| 221 | 301 | return \sprintf( 'keyId="%s",algorithm="rsa-sha256",headers="(request-target) host date digest",signature="%s"', $key_id, $signature ); |
| 222 | 302 | } else { |
| @@ -224,166 +304,53 @@ | ||
| 224 | 304 | } |
| 225 | 305 | } |
| 226 | 306 | |
| 227 | 307 | /** |
| 228 | - * Verifies the http signatures | |
| 308 | + * Gets the signature algorithm from the signature header. | |
| 229 | 309 | * |
| 230 | - * @param WP_REST_Request|array $request The request object or $_SERVER array. | |
| 310 | + * @deprecated 7.0.0 Use {@see Signature::verify()}. | |
| 231 | 311 | * |
| 232 | - * @return mixed A boolean or WP_Error. | |
| 233 | - */ | |
| 234 | - public static function verify_http_signature( $request ) { | |
| 235 | - if ( is_object( $request ) ) { // REST Request object | |
| 236 | - // check if route starts with "index.php" | |
| 237 | - if ( str_starts_with( $request->get_route(), '/index.php' ) || ! rest_get_url_prefix() ) { | |
| 238 | - $route = $request->get_route(); | |
| 239 | - } else { | |
| 240 | - $route = '/' . rest_get_url_prefix() . '/' . ltrim( $request->get_route(), '/' ); | |
| 241 | - } | |
| 242 | - | |
| 243 | - // fix route for subdirectory installs | |
| 244 | - $path = \wp_parse_url( \get_home_url(), PHP_URL_PATH ); | |
| 245 | - | |
| 246 | - if ( \is_string( $path ) ) { | |
| 247 | - $path = trim( $path, '/' ); | |
| 248 | - } | |
| 249 | - | |
| 250 | - if ( $path ) { | |
| 251 | - $route = '/' . $path . $route; | |
| 252 | - } | |
| 253 | - | |
| 254 | - $headers = $request->get_headers(); | |
| 255 | - $headers['(request-target)'][0] = strtolower( $request->get_method() ) . ' ' . $route; | |
| 256 | - } else { | |
| 257 | - $request = self::format_server_request( $request ); | |
| 258 | - $headers = $request['headers']; // $_SERVER array | |
| 259 | - $headers['(request-target)'][0] = strtolower( $headers['request_method'][0] ) . ' ' . $headers['request_uri'][0]; | |
| 260 | - } | |
| 261 | - | |
| 262 | - if ( ! isset( $headers['signature'] ) ) { | |
| 263 | - return new WP_Error( 'activitypub_signature', __( 'Request not signed', 'activitypub' ), array( 'status' => 401 ) ); | |
| 264 | - } | |
| 265 | - | |
| 266 | - if ( array_key_exists( 'signature', $headers ) ) { | |
| 267 | - $signature_block = self::parse_signature_header( $headers['signature'][0] ); | |
| 268 | - } elseif ( array_key_exists( 'authorization', $headers ) ) { | |
| 269 | - $signature_block = self::parse_signature_header( $headers['authorization'][0] ); | |
| 270 | - } | |
| 271 | - | |
| 272 | - if ( ! isset( $signature_block ) || ! $signature_block ) { | |
| 273 | - return new WP_Error( 'activitypub_signature', __( 'Incompatible request signature. keyId and signature are required', 'activitypub' ), array( 'status' => 401 ) ); | |
| 274 | - } | |
| 275 | - | |
| 276 | - $signed_headers = $signature_block['headers']; | |
| 277 | - if ( ! $signed_headers ) { | |
| 278 | - $signed_headers = array( 'date' ); | |
| 279 | - } | |
| 280 | - | |
| 281 | - $signed_data = self::get_signed_data( $signed_headers, $signature_block, $headers ); | |
| 282 | - if ( ! $signed_data ) { | |
| 283 | - return new WP_Error( 'activitypub_signature', __( 'Signed request date outside acceptable time window', 'activitypub' ), array( 'status' => 401 ) ); | |
| 284 | - } | |
| 285 | - | |
| 286 | - $algorithm = self::get_signature_algorithm( $signature_block ); | |
| 287 | - if ( ! $algorithm ) { | |
| 288 | - return new WP_Error( 'activitypub_signature', __( 'Unsupported signature algorithm (only rsa-sha256 and hs2019 are supported)', 'activitypub' ), array( 'status' => 401 ) ); | |
| 289 | - } | |
| 290 | - | |
| 291 | - if ( \in_array( 'digest', $signed_headers, true ) && isset( $body ) ) { | |
| 292 | - if ( is_array( $headers['digest'] ) ) { | |
| 293 | - $headers['digest'] = $headers['digest'][0]; | |
| 294 | - } | |
| 295 | - $hashalg = 'sha256'; | |
| 296 | - $digest = explode( '=', $headers['digest'], 2 ); | |
| 297 | - if ( 'SHA-256' === $digest[0] ) { | |
| 298 | - $hashalg = 'sha256'; | |
| 299 | - } | |
| 300 | - if ( 'SHA-512' === $digest[0] ) { | |
| 301 | - $hashalg = 'sha512'; | |
| 302 | - } | |
| 303 | - | |
| 304 | - if ( \base64_encode( \hash( $hashalg, $body, true ) ) !== $digest[1] ) { // phpcs:ignore | |
| 305 | - return new WP_Error( 'activitypub_signature', __( 'Invalid Digest header', 'activitypub' ), array( 'status' => 401 ) ); | |
| 306 | - } | |
| 307 | - } | |
| 308 | - | |
| 309 | - $public_key = self::get_remote_key( $signature_block['keyId'] ); | |
| 310 | - | |
| 311 | - if ( \is_wp_error( $public_key ) ) { | |
| 312 | - return $public_key; | |
| 313 | - } | |
| 314 | - | |
| 315 | - $verified = \openssl_verify( $signed_data, $signature_block['signature'], $public_key, $algorithm ) > 0; | |
| 316 | - | |
| 317 | - if ( ! $verified ) { | |
| 318 | - return new WP_Error( 'activitypub_signature', __( 'Invalid signature', 'activitypub' ), array( 'status' => 401 ) ); | |
| 319 | - } | |
| 320 | - return $verified; | |
| 321 | - } | |
| 322 | - | |
| 323 | - /** | |
| 324 | - * Get public key from key_id | |
| 312 | + * @param array $signature_block The signature block. | |
| 325 | 313 | * |
| 326 | - * @param string $key_id The URL to the public key. | |
| 327 | - * | |
| 328 | - * @return WP_Error|string The public key or WP_Error. | |
| 314 | + * @return string|bool The signature algorithm or false if not found. | |
| 329 | 315 | */ |
| 330 | - public static function get_remote_key( $key_id ) { // phpcs:ignore | |
| 331 | - $actor = get_remote_metadata_by_actor( strip_fragment_from_url( $key_id ) ); // phpcs:ignore | |
| 332 | - if ( \is_wp_error( $actor ) ) { | |
| 333 | - return new WP_Error( | |
| 334 | - 'activitypub_no_remote_profile_found', | |
| 335 | - __( 'No Profile found or Profile not accessible', 'activitypub' ), | |
| 336 | - array( 'status' => 401 ) | |
| 337 | - ); | |
| 338 | - } | |
| 339 | - if ( isset( $actor['publicKey']['publicKeyPem'] ) ) { | |
| 340 | - return \rtrim( $actor['publicKey']['publicKeyPem'] ); // phpcs:ignore | |
| 341 | - } | |
| 342 | - return new WP_Error( | |
| 343 | - 'activitypub_no_remote_key_found', | |
| 344 | - __( 'No Public-Key found', 'activitypub' ), | |
| 345 | - array( 'status' => 401 ) | |
| 346 | - ); | |
| 347 | - } | |
| 316 | + public static function get_signature_algorithm( $signature_block ) { // phpcs:ignore | |
| 317 | + \_deprecated_function( __METHOD__, '7.0.0', self::class . '::verify' ); | |
| 348 | 318 | |
| 349 | - /** | |
| 350 | - * Gets the signature algorithm from the signature header | |
| 351 | - * | |
| 352 | - * @param array $signature_block | |
| 353 | - * | |
| 354 | - * @return string The signature algorithm. | |
| 355 | - */ | |
| 356 | - public static function get_signature_algorithm( $signature_block ) { | |
| 357 | - if ( $signature_block['algorithm'] ) { | |
| 319 | + if ( ! empty( $signature_block['algorithm'] ) ) { | |
| 358 | 320 | switch ( $signature_block['algorithm'] ) { |
| 359 | 321 | case 'rsa-sha-512': |
| 360 | - return 'sha512'; //hs2019 https://datatracker.ietf.org/doc/html/draft-cavage-http-signatures-12 | |
| 322 | + return 'sha512'; // hs2019 https://datatracker.ietf.org/doc/html/draft-cavage-http-signatures-12. | |
| 361 | 323 | default: |
| 362 | 324 | return 'sha256'; |
| 363 | 325 | } |
| 364 | 326 | } |
| 327 | + | |
| 365 | 328 | return false; |
| 366 | 329 | } |
| 367 | 330 | |
| 368 | 331 | /** |
| 369 | - * Parses the Signature header | |
| 332 | + * Parses the Signature header. | |
| 370 | 333 | * |
| 334 | + * @deprecated 7.0.0 Use {@see Signature::verify()}. | |
| 335 | + * | |
| 371 | 336 | * @param string $signature The signature header. |
| 372 | 337 | * |
| 373 | - * @return array signature parts | |
| 338 | + * @return array Signature parts. | |
| 374 | 339 | */ |
| 375 | - public static function parse_signature_header( $signature ) { | |
| 376 | - $parsed_header = array(); | |
| 377 | - $matches = array(); | |
| 340 | + public static function parse_signature_header( $signature ) { // phpcs:ignore | |
| 341 | + \_deprecated_function( __METHOD__, '7.0.0', self::class . '::verify' ); | |
| 378 | 342 | |
| 343 | + $parsed_header = array(); | |
| 344 | + $matches = array(); | |
| 345 | + | |
| 379 | 346 | if ( \preg_match( '/keyId="(.*?)"/ism', $signature, $matches ) ) { |
| 380 | 347 | $parsed_header['keyId'] = trim( $matches[1] ); |
| 381 | 348 | } |
| 382 | - if ( \preg_match( '/created=([0-9]*)/ism', $signature, $matches ) ) { | |
| 349 | + if ( \preg_match( '/created=["|\']*([0-9]*)["|\']*/ism', $signature, $matches ) ) { | |
| 383 | 350 | $parsed_header['(created)'] = trim( $matches[1] ); |
| 384 | 351 | } |
| 385 | - if ( \preg_match( '/expires=([0-9]*)/ism', $signature, $matches ) ) { | |
| 352 | + if ( \preg_match( '/expires=["|\']*([0-9]*)["|\']*/ism', $signature, $matches ) ) { | |
| 386 | 353 | $parsed_header['(expires)'] = trim( $matches[1] ); |
| 387 | 354 | } |
| 388 | 355 | if ( \preg_match( '/algorithm="(.*?)"/ism', $signature, $matches ) ) { |
| 389 | 356 | $parsed_header['algorithm'] = trim( $matches[1] ); |
| @@ -391,12 +358,12 @@ | ||
| 391 | 358 | if ( \preg_match( '/headers="(.*?)"/ism', $signature, $matches ) ) { |
| 392 | 359 | $parsed_header['headers'] = \explode( ' ', trim( $matches[1] ) ); |
| 393 | 360 | } |
| 394 | 361 | if ( \preg_match( '/signature="(.*?)"/ism', $signature, $matches ) ) { |
| 395 | - $parsed_header['signature'] = \base64_decode( preg_replace( '/\s+/', '', trim( $matches[1] ) ) ); // phpcs:ignore | |
| 362 | + $parsed_header['signature'] = \base64_decode( preg_replace( '/\s+/', '', trim( $matches[1] ) ) ); // phpcs:ignore WordPress.PHP.DiscouragedPHPFunctions.obfuscation_base64_decode | |
| 396 | 363 | } |
| 397 | 364 | |
| 398 | - if ( ( $parsed_header['signature'] ) && ( $parsed_header['algorithm'] ) && ( ! $parsed_header['headers'] ) ) { | |
| 365 | + if ( empty( $parsed_header['headers'] ) ) { | |
| 399 | 366 | $parsed_header['headers'] = array( 'date' ); |
| 400 | 367 | } |
| 401 | 368 | |
| 402 | 369 | return $parsed_header; |
| @@ -402,18 +369,23 @@ | ||
| 402 | 369 | return $parsed_header; |
| 403 | 370 | } |
| 404 | 371 | |
| 405 | 372 | /** |
| 406 | - * Gets the header data from the included pseudo headers | |
| 373 | + * Gets the header data from the included pseudo headers. | |
| 407 | 374 | * |
| 375 | + * @deprecated 7.0.0 Use {@see Signature::verify()}. | |
| 376 | + * | |
| 408 | 377 | * @param array $signed_headers The signed headers. |
| 409 | - * @param array $signature_block (pseudo-headers) | |
| 410 | - * @param array $headers (http headers) | |
| 378 | + * @param array $signature_block The signature block. | |
| 379 | + * @param array $headers The HTTP headers. | |
| 411 | 380 | * |
| 412 | 381 | * @return string signed headers for comparison |
| 413 | 382 | */ |
| 414 | - public static function get_signed_data( $signed_headers, $signature_block, $headers ) { | |
| 383 | + public static function get_signed_data( $signed_headers, $signature_block, $headers ) { // phpcs:ignore | |
| 384 | + \_deprecated_function( __METHOD__, '7.0.0', self::class . '::verify' ); | |
| 385 | + | |
| 415 | 386 | $signed_data = ''; |
| 387 | + | |
| 416 | 388 | // This also verifies time-based values by returning false if any of these are out of range. |
| 417 | 389 | foreach ( $signed_headers as $header ) { |
| 418 | 390 | if ( 'host' === $header ) { |
| 419 | 391 | if ( isset( $headers['x_original_host'] ) ) { |
| @@ -430,71 +402,160 @@ | ||
| 430 | 402 | continue; |
| 431 | 403 | } |
| 432 | 404 | if ( '(created)' === $header ) { |
| 433 | 405 | if ( ! empty( $signature_block['(created)'] ) && \intval( $signature_block['(created)'] ) > \time() ) { |
| 434 | - // created in future | |
| 406 | + // Created in the future. | |
| 435 | 407 | return false; |
| 436 | 408 | } |
| 409 | + | |
| 410 | + if ( ! array_key_exists( '(created)', $headers ) ) { | |
| 411 | + $signed_data .= $header . ': ' . $signature_block['(created)'] . "\n"; | |
| 412 | + continue; | |
| 413 | + } | |
| 437 | 414 | } |
| 438 | 415 | if ( '(expires)' === $header ) { |
| 439 | 416 | if ( ! empty( $signature_block['(expires)'] ) && \intval( $signature_block['(expires)'] ) < \time() ) { |
| 440 | - // expired in past | |
| 417 | + // Expired in the past. | |
| 441 | 418 | return false; |
| 442 | 419 | } |
| 420 | + | |
| 421 | + if ( ! array_key_exists( '(expires)', $headers ) ) { | |
| 422 | + $signed_data .= $header . ': ' . $signature_block['(expires)'] . "\n"; | |
| 423 | + continue; | |
| 424 | + } | |
| 443 | 425 | } |
| 444 | 426 | if ( 'date' === $header ) { |
| 445 | - // allow a bit of leeway for misconfigured clocks. | |
| 446 | - $d = new DateTime( $headers[ $header ][0] ); | |
| 447 | - $d->setTimeZone( new DateTimeZone( 'UTC' ) ); | |
| 427 | + if ( empty( $headers[ $header ][0] ) ) { | |
| 428 | + continue; | |
| 429 | + } | |
| 430 | + | |
| 431 | + // Allow a bit of leeway for misconfigured clocks. | |
| 432 | + $d = new \DateTime( $headers[ $header ][0] ); | |
| 433 | + $d->setTimeZone( new \DateTimeZone( 'UTC' ) ); | |
| 448 | 434 | $c = $d->format( 'U' ); |
| 449 | 435 | |
| 450 | - $dplus = time() + ( 3 * HOUR_IN_SECONDS ); | |
| 451 | - $dminus = time() - ( 3 * HOUR_IN_SECONDS ); | |
| 436 | + $d_plus = time() + ( 3 * HOUR_IN_SECONDS ); | |
| 437 | + $d_minus = time() - ( 3 * HOUR_IN_SECONDS ); | |
| 452 | 438 | |
| 453 | - if ( $c > $dplus || $c < $dminus ) { | |
| 454 | - // time out of range | |
| 439 | + if ( $c > $d_plus || $c < $d_minus ) { | |
| 440 | + // Time out of range. | |
| 455 | 441 | return false; |
| 456 | 442 | } |
| 457 | 443 | } |
| 458 | - $signed_data .= $header . ': ' . $headers[ $header ][0] . "\n"; | |
| 444 | + | |
| 445 | + if ( ! empty( $headers[ $header ][0] ) ) { | |
| 446 | + $signed_data .= $header . ': ' . $headers[ $header ][0] . "\n"; | |
| 447 | + } | |
| 459 | 448 | } |
| 449 | + | |
| 460 | 450 | return \rtrim( $signed_data, "\n" ); |
| 461 | 451 | } |
| 462 | 452 | |
| 463 | 453 | /** |
| 464 | - * Generates the digest for a HTTP Request | |
| 454 | + * Generates the digest for an HTTP Request. | |
| 465 | 455 | * |
| 456 | + * @deprecated 7.0.0 Use {@see Signature::sign_request()}. | |
| 457 | + * | |
| 466 | 458 | * @param string $body The body of the request. |
| 467 | 459 | * |
| 468 | 460 | * @return string The digest. |
| 469 | 461 | */ |
| 470 | 462 | public static function generate_digest( $body ) { |
| 471 | - $digest = \base64_encode( \hash( 'sha256', $body, true ) ); // phpcs:ignore | |
| 463 | + \_deprecated_function( __METHOD__, '7.0.0', self::class . '::sign_request' ); | |
| 464 | + | |
| 465 | + $digest = \base64_encode( \hash( 'sha256', $body, true ) ); // phpcs:ignore WordPress.PHP.DiscouragedPHPFunctions.obfuscation_base64_encode | |
| 472 | 466 | return "SHA-256=$digest"; |
| 473 | 467 | } |
| 474 | 468 | |
| 475 | 469 | /** |
| 476 | - * Formats the $_SERVER to resemble the WP_REST_REQUEST array, | |
| 477 | - * for use with verify_http_signature() | |
| 470 | + * Compute the collection digest for a specific instance. | |
| 478 | 471 | * |
| 479 | - * @param array $_SERVER The $_SERVER array. | |
| 472 | + * Implements FEP-8fcf: Followers collection synchronization. | |
| 473 | + * The digest is created by XORing together the individual SHA256 digests | |
| 474 | + * of each follower's ID. | |
| 480 | 475 | * |
| 481 | - * @return array $request The formatted request array. | |
| 476 | + * @see https://codeberg.org/fediverse/fep/src/branch/main/fep/8fcf/fep-8fcf.md | |
| 477 | + * | |
| 478 | + * @param array $collection The user ID whose followers to compute. | |
| 479 | + * | |
| 480 | + * @return string|false The hex-encoded digest, or false if no followers. | |
| 482 | 481 | */ |
| 483 | - public static function format_server_request( $server ) { | |
| 484 | - $request = array(); | |
| 485 | - foreach ( $server as $param_key => $param_val ) { | |
| 486 | - $req_param = strtolower( $param_key ); | |
| 487 | - if ( 'REQUEST_URI' === $req_param ) { | |
| 488 | - $request['headers']['route'][] = $param_val; | |
| 489 | - } else { | |
| 490 | - $header_key = str_replace( | |
| 491 | - 'http_', | |
| 492 | - '', | |
| 493 | - $req_param | |
| 494 | - ); | |
| 495 | - $request['headers'][ $header_key ][] = \wp_unslash( $param_val ); | |
| 482 | + public static function get_collection_digest( $collection ) { | |
| 483 | + if ( empty( $collection ) || ! is_array( $collection ) ) { | |
| 484 | + return false; | |
| 485 | + } | |
| 486 | + | |
| 487 | + // Initialize with zeros (64 hex chars = 32 bytes = 256 bits). | |
| 488 | + $digest = str_repeat( '0', 64 ); | |
| 489 | + | |
| 490 | + foreach ( $collection as $item ) { | |
| 491 | + // Compute SHA256 hash of the follower ID. | |
| 492 | + $hash = hash( 'sha256', $item ); | |
| 493 | + | |
| 494 | + // XOR the hash with the running digest. | |
| 495 | + $digest = self::xor_hex_strings( $digest, $hash ); | |
| 496 | + } | |
| 497 | + | |
| 498 | + return $digest; | |
| 499 | + } | |
| 500 | + | |
| 501 | + /** | |
| 502 | + * XOR two hexadecimal strings. | |
| 503 | + * | |
| 504 | + * Used for FEP-8fcf digest computation. | |
| 505 | + * | |
| 506 | + * @param string $hex1 First hex string. | |
| 507 | + * @param string $hex2 Second hex string. | |
| 508 | + * | |
| 509 | + * @return string The XORed result as a hex string. | |
| 510 | + */ | |
| 511 | + public static function xor_hex_strings( $hex1, $hex2 ) { | |
| 512 | + $result = ''; | |
| 513 | + | |
| 514 | + // Ensure both strings are the same length (should be 64 chars for SHA256). | |
| 515 | + $length = \max( \strlen( $hex1 ), \strlen( $hex2 ) ); | |
| 516 | + $hex1 = \str_pad( $hex1, $length, '0', STR_PAD_LEFT ); | |
| 517 | + $hex2 = \str_pad( $hex2, $length, '0', STR_PAD_LEFT ); | |
| 518 | + | |
| 519 | + // XOR each pair of hex digits. | |
| 520 | + for ( $i = 0; $i < $length; $i += 2 ) { | |
| 521 | + $byte1 = \hexdec( \substr( $hex1, $i, 2 ) ); | |
| 522 | + $byte2 = \hexdec( \substr( $hex2, $i, 2 ) ); | |
| 523 | + $result .= \str_pad( \dechex( $byte1 ^ $byte2 ), 2, '0', STR_PAD_LEFT ); | |
| 524 | + } | |
| 525 | + | |
| 526 | + return $result; | |
| 527 | + } | |
| 528 | + | |
| 529 | + /** | |
| 530 | + * Parse a Collection-Synchronization header (FEP-8fcf). | |
| 531 | + * | |
| 532 | + * Parses the signature-style format used by the Collection-Synchronization header. | |
| 533 | + * | |
| 534 | + * @see https://codeberg.org/fediverse/fep/src/branch/main/fep/8fcf/fep-8fcf.md | |
| 535 | + * | |
| 536 | + * @param string $header The header value. | |
| 537 | + * | |
| 538 | + * @return array|false Array with parsed parameters (collectionId, url, digest), or false on failure. | |
| 539 | + */ | |
| 540 | + public static function parse_collection_sync_header( $header ) { | |
| 541 | + if ( empty( $header ) ) { | |
| 542 | + return false; | |
| 543 | + } | |
| 544 | + | |
| 545 | + // Parse the signature-style format: key="value", key="value". | |
| 546 | + $params = array(); | |
| 547 | + | |
| 548 | + if ( \preg_match_all( '/(\w+)="([^"]*)"/', $header, $matches, PREG_SET_ORDER ) ) { | |
| 549 | + foreach ( $matches as $match ) { | |
| 550 | + $params[ $match[1] ] = $match[2]; | |
| 496 | 551 | } |
| 497 | 552 | } |
| 498 | - return $request; | |
| 553 | + | |
| 554 | + // Validate required fields for FEP-8fcf. | |
| 555 | + if ( empty( $params['collectionId'] ) || empty( $params['url'] ) || empty( $params['digest'] ) ) { | |
| 556 | + return false; | |
| 557 | + } | |
| 558 | + | |
| 559 | + return $params; | |
| 499 | 560 | } |
| 500 | 561 | } |
