jetpack
/
jetpack_vendor
/
automattic
/
jetpack-comments
/
src
/
identity
/
checkpoint
/
class-checkpoint.php
class-checkpoint.php in Jetpack – WP Security, Backup, Speed, & Growth 16.3-beta, at jetpack_vendor/automattic/jetpack-comments/src/identity/checkpoint/class-checkpoint.php
| 1 | <?php |
| 2 | /** |
| 3 | * The checkpoint: where a commenter signed in through WordPress.com is admitted. |
| 4 | * |
| 5 | * @package automattic/jetpack-comments |
| 6 | */ |
| 7 | |
| 8 | namespace Automattic\Jetpack\Comments; |
| 9 | |
| 10 | use Automattic\Jetpack\Connection\Client; |
| 11 | use Automattic\Jetpack\Connection\Manager; |
| 12 | use Automattic\Jetpack\Connection\Tokens; |
| 13 | use WP_Error; |
| 14 | |
| 15 | /** |
| 16 | * Signs the popup URL, redeems the code it hands back, and attributes the comment. |
| 17 | * |
| 18 | * The WordPress.com half is the Consulate in wpcom's lib/comment-identity. |
| 19 | */ |
| 20 | class Checkpoint { |
| 21 | |
| 22 | const CODE_FIELD = 'jetpack_comment_identity_code'; |
| 23 | // Sent when the form rendered as signed in on the passport. Without it the passport is |
| 24 | // left alone, so a log-out that never reached the server still posts as the guest shown. |
| 25 | const PASSPORT_FIELD = 'jetpack_comment_identity_passport'; |
| 26 | // Comment meta: the commenter's provider and avatar. |
| 27 | const META_PROVIDER = 'jetpack_comment_identity_provider'; |
| 28 | const META_AVATAR = 'jetpack_comment_identity_avatar'; |
| 29 | |
| 30 | /** |
| 31 | * Singleton instance. |
| 32 | * |
| 33 | * @var Checkpoint|null |
| 34 | */ |
| 35 | private static $instance = null; |
| 36 | |
| 37 | /** |
| 38 | * Whether a signing key exists, memoized per request. |
| 39 | * |
| 40 | * @var bool|null |
| 41 | */ |
| 42 | private static $available = null; |
| 43 | |
| 44 | /** |
| 45 | * The identity admitted for the comment being posted now. |
| 46 | * |
| 47 | * @var array|null |
| 48 | */ |
| 49 | private $identity = null; |
| 50 | |
| 51 | /** |
| 52 | * Register the hooks. Safe to call more than once. |
| 53 | * |
| 54 | * @return Checkpoint |
| 55 | */ |
| 56 | public static function init() { |
| 57 | if ( null === self::$instance ) { |
| 58 | self::$instance = new self(); |
| 59 | } |
| 60 | |
| 61 | return self::$instance; |
| 62 | } |
| 63 | |
| 64 | /** |
| 65 | * Hook in around core's comment handling. |
| 66 | */ |
| 67 | private function __construct() { |
| 68 | // After Comment_Form::verify_nonce() at 10, so an unsigned post never reaches the exchange. |
| 69 | add_action( 'pre_comment_on_post', array( $this, 'admit' ), 20 ); |
| 70 | add_filter( 'preprocess_comment', array( $this, 'attribute' ), 0 ); |
| 71 | add_action( 'comment_post', array( $this, 'record' ) ); |
| 72 | |
| 73 | Checkpoint_Endpoint::init(); |
| 74 | } |
| 75 | |
| 76 | /** |
| 77 | * Whether this site can sign a popup URL. |
| 78 | * |
| 79 | * @return bool |
| 80 | */ |
| 81 | public static function is_available() { |
| 82 | if ( null !== self::$available ) { |
| 83 | return self::$available; |
| 84 | } |
| 85 | |
| 86 | if ( defined( 'IS_WPCOM' ) && IS_WPCOM ) { |
| 87 | self::$available = file_exists( WP_CONTENT_DIR . '/lib/comment-identity/class-consulate.php' ); |
| 88 | } else { |
| 89 | $token = ( new Tokens() )->get_access_token(); |
| 90 | self::$available = $token && ! is_wp_error( $token ) && ! empty( $token->secret ); |
| 91 | } |
| 92 | |
| 93 | return self::$available; |
| 94 | } |
| 95 | |
| 96 | /** |
| 97 | * Whether a challenge has the shape the popup echoes back. |
| 98 | * |
| 99 | * @param mixed $challenge The value to check. |
| 100 | * @return bool |
| 101 | */ |
| 102 | public static function is_challenge( $challenge ) { |
| 103 | return is_string( $challenge ) && 1 === preg_match( '/^[A-Za-z0-9_-]{32,512}\z/', $challenge ); |
| 104 | } |
| 105 | |
| 106 | /** |
| 107 | * A signed popup URL: with the blog token, or on Simple with the Consulate's own key. |
| 108 | * |
| 109 | * @param string $challenge The challenge to sign. |
| 110 | * @return array|WP_Error url, expires, challenge. |
| 111 | */ |
| 112 | public static function connect_url( $challenge ) { |
| 113 | if ( ! self::is_challenge( $challenge ) ) { |
| 114 | return new WP_Error( 'invalid_request', __( 'Invalid request.', 'jetpack-comments' ), array( 'status' => 400 ) ); |
| 115 | } |
| 116 | |
| 117 | if ( ! self::is_available() ) { |
| 118 | return new WP_Error( 'unavailable', __( 'Sign-in is not available on this site.', 'jetpack-comments' ), array( 'status' => 503 ) ); |
| 119 | } |
| 120 | |
| 121 | // Scheme, host and port of the page the popup posts back to. |
| 122 | $home = wp_parse_url( home_url() ); |
| 123 | $origin = ( $home['scheme'] ?? 'https' ) . '://' . ( $home['host'] ?? '' ) . ( empty( $home['port'] ) ? '' : ':' . $home['port'] ); |
| 124 | |
| 125 | $params = array( |
| 126 | 'blog_id' => self::blog_id(), |
| 127 | // The only provider, and part of what WordPress.com verifies. |
| 128 | 'provider' => 'wordpress', |
| 129 | 'challenge' => $challenge, |
| 130 | 'origin' => $origin, |
| 131 | // WordPress.com rejects an expiry past ten minutes out; a minute is left for clock skew. |
| 132 | 'expires' => time() + 9 * MINUTE_IN_SECONDS, |
| 133 | ); |
| 134 | |
| 135 | if ( defined( 'IS_WPCOM' ) && IS_WPCOM ) { |
| 136 | require_once WP_CONTENT_DIR . '/lib/comment-identity/class-consulate.php'; |
| 137 | |
| 138 | // @phan-suppress-next-line PhanUndeclaredClassMethod -- wpcom-only; add to stub-defs.php when the wpcom half lands. |
| 139 | $signature = \Automattic\Comment_Identity\Consulate::sign( $params ); |
| 140 | } else { |
| 141 | // Key=value lines sorted by key, exactly as Consulate::signing_payload() on WordPress.com builds them. |
| 142 | $signed = $params; |
| 143 | ksort( $signed ); |
| 144 | |
| 145 | $lines = array(); |
| 146 | foreach ( $signed as $key => $value ) { |
| 147 | $lines[] = $key . '=' . $value; |
| 148 | } |
| 149 | |
| 150 | $signature = hash_hmac( 'sha256', implode( "\n", $lines ), ( new Tokens() )->get_access_token()->secret ); |
| 151 | } |
| 152 | |
| 153 | $query = array_merge( array( 'comment_identity' => 1 ), $params, array( 'signature' => $signature ) ); |
| 154 | |
| 155 | return array( |
| 156 | 'url' => 'https://public-api.wordpress.com/connect/?' . http_build_query( $query, '', '&', PHP_QUERY_RFC3986 ), |
| 157 | 'expires' => $params['expires'], |
| 158 | 'challenge' => $challenge, |
| 159 | ); |
| 160 | } |
| 161 | |
| 162 | /** |
| 163 | * The site's id on WordPress.com. |
| 164 | * |
| 165 | * @return int |
| 166 | */ |
| 167 | public static function blog_id() { |
| 168 | return (int) Manager::get_site_id( true ); |
| 169 | } |
| 170 | |
| 171 | /** |
| 172 | * Redeem a code with WordPress.com. |
| 173 | * |
| 174 | * @param string $code The code the popup handed back. |
| 175 | * @return array|WP_Error site_commenter_id, provider, name, email, avatar, expires_at. |
| 176 | */ |
| 177 | public static function exchange( $code ) { |
| 178 | $response = Client::wpcom_json_api_request_as_blog( |
| 179 | sprintf( '/sites/%d/comments/identity/exchange', self::blog_id() ), |
| 180 | '2', |
| 181 | array( |
| 182 | 'method' => 'POST', |
| 183 | 'headers' => array( 'Content-Type' => 'application/json; charset=utf-8' ), |
| 184 | 'timeout' => 10, |
| 185 | ), |
| 186 | (string) wp_json_encode( array( 'code' => (string) $code ), JSON_UNESCAPED_SLASHES ), |
| 187 | 'wpcom' |
| 188 | ); |
| 189 | |
| 190 | $known = array( 'invalid_code', 'blog_mismatch', 'code_used', 'code_expired', 'rate_limited', 'server_error' ); |
| 191 | |
| 192 | if ( is_wp_error( $response ) ) { |
| 193 | $data = (array) $response->get_error_data(); |
| 194 | $code = in_array( $response->get_error_code(), $known, true ) ? $response->get_error_code() : 'server_error'; |
| 195 | |
| 196 | return new WP_Error( $code, $response->get_error_message(), array( 'status' => (int) ( $data['status'] ?? 500 ) ) ); |
| 197 | } |
| 198 | |
| 199 | $status = (int) wp_remote_retrieve_response_code( $response ); |
| 200 | $body = json_decode( wp_remote_retrieve_body( $response ), true ); |
| 201 | |
| 202 | if ( 200 === $status && is_array( $body ) && ! empty( $body['site_commenter_id'] ) && ! empty( $body['provider'] ) ) { |
| 203 | return array( |
| 204 | 'site_commenter_id' => sanitize_text_field( (string) $body['site_commenter_id'] ), |
| 205 | 'provider' => sanitize_key( (string) $body['provider'] ), |
| 206 | 'name' => sanitize_text_field( (string) ( $body['name'] ?? '' ) ), |
| 207 | 'email' => sanitize_email( (string) ( $body['email'] ?? '' ) ), |
| 208 | 'avatar' => esc_url_raw( (string) ( $body['avatar'] ?? '' ) ), |
| 209 | 'expires_at' => (int) ( $body['expires_at'] ?? 0 ), |
| 210 | ); |
| 211 | } |
| 212 | |
| 213 | $error = is_array( $body ) && isset( $body['code'] ) && in_array( $body['code'], $known, true ) ? $body['code'] : 'server_error'; |
| 214 | |
| 215 | return new WP_Error( |
| 216 | $error, |
| 217 | is_array( $body ) && ! empty( $body['message'] ) ? (string) $body['message'] : '', |
| 218 | array( |
| 219 | 'status' => $status ? $status : 500, |
| 220 | 'retry_after' => (int) wp_remote_retrieve_header( $response, 'retry-after' ), |
| 221 | ) |
| 222 | ); |
| 223 | } |
| 224 | |
| 225 | /** |
| 226 | * Admit the commenter, from the code they posted or the passport they carry. |
| 227 | * |
| 228 | * @param int $comment_post_id The post being commented on. |
| 229 | * @return void |
| 230 | */ |
| 231 | public function admit( $comment_post_id = 0 ) { |
| 232 | if ( ! Comment_Form::enabled_for_post_type( $comment_post_id ) || is_user_logged_in() ) { |
| 233 | return; |
| 234 | } |
| 235 | |
| 236 | // phpcs:disable WordPress.Security.NonceVerification.Missing -- Comment_Form::verify_nonce() ran at priority 10. |
| 237 | $code = isset( $_POST[ self::CODE_FIELD ] ) ? sanitize_text_field( wp_unslash( $_POST[ self::CODE_FIELD ] ) ) : ''; |
| 238 | $on_passport = ! empty( $_POST[ self::PASSPORT_FIELD ] ); |
| 239 | // phpcs:enable WordPress.Security.NonceVerification.Missing |
| 240 | |
| 241 | if ( '' !== $code ) { |
| 242 | $identity = self::exchange( $code ); |
| 243 | |
| 244 | if ( is_wp_error( $identity ) ) { |
| 245 | self::refuse( $identity ); |
| 246 | } |
| 247 | |
| 248 | Passport::issue( $identity ); |
| 249 | } elseif ( $on_passport ) { |
| 250 | $identity = Passport::read(); |
| 251 | |
| 252 | // The form showed a name the passport no longer backs, say after a |
| 253 | // log-out in another tab. Refusing beats publishing as a guest. |
| 254 | if ( null === $identity ) { |
| 255 | self::refuse( new WP_Error( 'code_expired', '', array( 'status' => 403 ) ) ); |
| 256 | } |
| 257 | } else { |
| 258 | return; |
| 259 | } |
| 260 | |
| 261 | $this->identity = $identity; |
| 262 | |
| 263 | // A signed-in commenter counts as registered, and has given a name and email. |
| 264 | add_filter( 'pre_option_comment_registration', '__return_zero' ); |
| 265 | add_filter( 'pre_option_require_name_email', '__return_zero' ); |
| 266 | } |
| 267 | |
| 268 | /** |
| 269 | * Turn the comment away. Does not return. |
| 270 | * |
| 271 | * @param WP_Error $error From exchange(). |
| 272 | * @return void |
| 273 | */ |
| 274 | private static function refuse( WP_Error $error ) { |
| 275 | $data = (array) $error->get_error_data(); |
| 276 | $status = (int) ( $data['status'] ?? 500 ); |
| 277 | |
| 278 | switch ( $error->get_error_code() ) { |
| 279 | case 'code_expired': |
| 280 | case 'code_used': |
| 281 | // The sign-in is spent; nothing here can be reused. |
| 282 | Passport::revoke(); |
| 283 | $message = __( 'Your sign-in has expired. Go back and sign in again to leave your comment.', 'jetpack-comments' ); |
| 284 | $status = 403; |
| 285 | break; |
| 286 | |
| 287 | case 'rate_limited': |
| 288 | $message = __( 'Too many sign-in attempts right now. Go back and try again in a moment.', 'jetpack-comments' ); |
| 289 | if ( ! empty( $data['retry_after'] ) ) { |
| 290 | header( 'Retry-After: ' . (int) $data['retry_after'] ); // phpcs:ignore WordPress.Security.EscapeOutput.OutputNotEscaped -- an integer header value. |
| 291 | } |
| 292 | break; |
| 293 | |
| 294 | case 'invalid_code': |
| 295 | case 'blog_mismatch': |
| 296 | $message = __( 'Your sign-in could not be verified. Go back and sign in again to leave your comment.', 'jetpack-comments' ); |
| 297 | break; |
| 298 | |
| 299 | default: |
| 300 | $message = __( 'Sign-in is unavailable right now. Go back and try again in a moment.', 'jetpack-comments' ); |
| 301 | break; |
| 302 | } |
| 303 | |
| 304 | wp_die( |
| 305 | esc_html( $message ), |
| 306 | esc_html__( 'Comment Submission Failure', 'jetpack-comments' ), |
| 307 | array( |
| 308 | 'response' => absint( $status ), |
| 309 | 'back_link' => true, |
| 310 | ) |
| 311 | ); |
| 312 | } |
| 313 | |
| 314 | /** |
| 315 | * Attribute the comment to the admitted identity. |
| 316 | * |
| 317 | * @param array $commentdata Comment data. |
| 318 | * @return array |
| 319 | */ |
| 320 | public function attribute( $commentdata ) { |
| 321 | if ( null === $this->identity ) { |
| 322 | return $commentdata; |
| 323 | } |
| 324 | |
| 325 | $commentdata['comment_author'] = $this->identity['name']; |
| 326 | $commentdata['comment_author_email'] = $this->identity['email']; |
| 327 | $commentdata['comment_author_url'] = ''; |
| 328 | $commentdata['user_id'] = 0; |
| 329 | $commentdata['user_ID'] = 0; |
| 330 | |
| 331 | return $commentdata; |
| 332 | } |
| 333 | |
| 334 | /** |
| 335 | * Record who left the comment, from the identity admitted on this request rather than $_POST. |
| 336 | * |
| 337 | * @param int $comment_id The comment ID. |
| 338 | * @return void |
| 339 | */ |
| 340 | public function record( $comment_id ) { |
| 341 | if ( null === $this->identity ) { |
| 342 | return; |
| 343 | } |
| 344 | |
| 345 | add_comment_meta( $comment_id, 'jetpack_comment_identity_id', $this->identity['site_commenter_id'], true ); |
| 346 | add_comment_meta( $comment_id, self::META_PROVIDER, $this->identity['provider'], true ); |
| 347 | |
| 348 | if ( '' !== $this->identity['avatar'] ) { |
| 349 | add_comment_meta( $comment_id, self::META_AVATAR, $this->identity['avatar'], true ); |
| 350 | } |
| 351 | } |
| 352 | } |
| 353 |