| 1 |
<?php |
| 2 |
/** |
| 3 |
* Acknowledged Signls delivery transport. |
| 4 |
* |
| 5 |
* @package signls-sdk |
| 6 |
* @license GPL-3.0-or-later |
| 7 |
*/ |
| 8 |
|
| 9 |
namespace Signls\Sdk\V1; |
| 10 |
|
| 11 |
defined( 'ABSPATH' ) || exit; |
| 12 |
|
| 13 |
final class Transport { |
| 14 |
|
| 15 |
private const DEFAULT_ENDPOINT = 'https://signls.dev'; |
| 16 |
|
| 17 |
private const SDK_VERSION = '1.1.10'; |
| 18 |
|
| 19 |
private const CLOCK_SKEW_SECONDS = 300; |
| 20 |
|
| 21 |
private const QUARANTINE_CLASSES = array( |
| 22 |
'invalid_json', |
| 23 |
'invalid_schema', |
| 24 |
'invalid_bounds', |
| 25 |
'contract_violation', |
| 26 |
'payload_too_large', |
| 27 |
'unknown_product', |
| 28 |
); |
| 29 |
|
| 30 |
private $state; |
| 31 |
|
| 32 |
private $identity; |
| 33 |
|
| 34 |
private $site_identity; |
| 35 |
|
| 36 |
public function __construct( StateStore $state, Identity $identity, SiteIdentity $site_identity ) { |
| 37 |
$this->state = $state; |
| 38 |
$this->identity = $identity; |
| 39 |
$this->site_identity = $site_identity; |
| 40 |
} |
| 41 |
|
| 42 |
public static function version(): string { |
| 43 |
return self::SDK_VERSION; |
| 44 |
} |
| 45 |
|
| 46 |
public function prepare( ProductAdapterInterface $adapter ) { |
| 47 |
$revision = $this->payload_revision( $adapter ); |
| 48 |
$pending = $this->reconcile_pending_identity( $adapter, $revision ); |
| 49 |
if ( '' === $pending || '' === (string) $this->state->get( 'pending_quarantine_class', '' ) ) { |
| 50 |
return null; |
| 51 |
} |
| 52 |
|
| 53 |
$probe_at = (int) $this->state->get( 'pending_quarantine_probe_at', 0 ); |
| 54 |
if ( $probe_at <= time() ) { |
| 55 |
return null; |
| 56 |
} |
| 57 |
|
| 58 |
return array( |
| 59 |
'ok' => false, |
| 60 |
'class' => Sanitizer::slug( $this->state->get( 'pending_quarantine_class', '' ), 48, 'contract_violation' ), |
| 61 |
'status' => (int) $this->state->get( 'pending_quarantine_status', 0 ), |
| 62 |
'permanent' => true, |
| 63 |
'quarantined' => true, |
| 64 |
); |
| 65 |
} |
| 66 |
|
| 67 |
public function has_compatible_pending( ProductAdapterInterface $adapter ): bool { |
| 68 |
return '' !== $this->reconcile_pending_identity( $adapter, $this->payload_revision( $adapter ) ); |
| 69 |
} |
| 70 |
|
| 71 |
public function deliver( ProductAdapterInterface $adapter, array $payload ): array { |
| 72 |
$started = time(); |
| 73 |
$this->state->set( 'last_attempt_started_at', $started ); |
| 74 |
|
| 75 |
if ( '' === (string) $this->state->get( 'credential_id', '' ) ) { |
| 76 |
$enrollment = $this->enroll( $adapter, false ); |
| 77 |
if ( ! $enrollment['ok'] ) { |
| 78 |
return $this->finish( $enrollment ); |
| 79 |
} |
| 80 |
} |
| 81 |
|
| 82 |
$result = $this->snapshot( $adapter, $payload, false, false ); |
| 83 |
if ( 'stale_timestamp' === $result['class'] && empty( $result['quarantined'] ) && isset( $result['server_time'] ) ) { |
| 84 |
$server_time = (int) $result['server_time']; |
| 85 |
$clear_future = $this->pending_observed_at_is_future( $server_time ); |
| 86 |
if ( $this->state->apply_clock_correction( $server_time - time(), $clear_future ) ) { |
| 87 |
$result = $this->snapshot( $adapter, $payload, true, false ); |
| 88 |
} |
| 89 |
} |
| 90 |
return $this->finish( $result ); |
| 91 |
} |
| 92 |
|
| 93 |
public static function retry_delay( int $attempt ): int { |
| 94 |
$delays = array( 900, 3600, 14400, 43200, 86400 ); |
| 95 |
return $delays[ min( max( 0, $attempt ), count( $delays ) - 1 ) ]; |
| 96 |
} |
| 97 |
|
| 98 |
private function enroll( ProductAdapterInterface $adapter, bool $clock_retry ): array { |
| 99 |
$body = array( |
| 100 |
'schema_version' => 1, |
| 101 |
'sdk_version' => self::SDK_VERSION, |
| 102 |
'product' => $adapter->product_slug(), |
| 103 |
'install_id' => $adapter->install_id(), |
| 104 |
'device_id' => $this->identity->device_id(), |
| 105 |
'timestamp' => time() + (int) $this->state->get( 'clock_offset', 0 ), |
| 106 |
); |
| 107 |
$encoded = wp_json_encode( $body ); |
| 108 |
if ( ! is_string( $encoded ) ) { |
| 109 |
return array( |
| 110 |
'ok' => false, |
| 111 |
'class' => 'invalid_payload', |
| 112 |
'status' => 0, |
| 113 |
'permanent' => true, |
| 114 |
); |
| 115 |
} |
| 116 |
$response = $this->post( '/signals/v2/enroll', $encoded, array() ); |
| 117 |
if ( 'stale_timestamp' === $response['class'] && ! $clock_retry && isset( $response['data']['server_time'] ) ) { |
| 118 |
$this->state->set( 'clock_offset', (int) $response['data']['server_time'] - time() ); |
| 119 |
return $this->enroll( $adapter, true ); |
| 120 |
} |
| 121 |
if ( ! $response['ok'] ) { |
| 122 |
return $response; |
| 123 |
} |
| 124 |
|
| 125 |
$data = $response['data']; |
| 126 |
if ( ! isset( $data['credential_id'], $data['credential_secret'], $data['key_id'], $data['server_time'] ) || ! is_string( $data['credential_id'] ) || ! is_string( $data['credential_secret'] ) || ! is_string( $data['key_id'] ) ) { |
| 127 |
return array( |
| 128 |
'ok' => false, |
| 129 |
'class' => 'invalid_response', |
| 130 |
'status' => $response['status'], |
| 131 |
'permanent' => true, |
| 132 |
); |
| 133 |
} |
| 134 |
|
| 135 |
$this->state->set_many( |
| 136 |
array( |
| 137 |
'credential_id' => substr( $data['credential_id'], 0, 64 ), |
| 138 |
'credential_secret' => substr( $data['credential_secret'], 0, 128 ), |
| 139 |
'credential_key_id' => substr( $data['key_id'], 0, 48 ), |
| 140 |
'clock_offset' => (int) $data['server_time'] - time(), |
| 141 |
) |
| 142 |
); |
| 143 |
return array( |
| 144 |
'ok' => true, |
| 145 |
'class' => 'enrolled', |
| 146 |
'status' => $response['status'], |
| 147 |
'permanent' => false, |
| 148 |
); |
| 149 |
} |
| 150 |
|
| 151 |
private function snapshot( ProductAdapterInterface $adapter, array $payload, bool $clock_retry, bool $sequence_retry ): array { |
| 152 |
$contract = $adapter->contract(); |
| 153 |
$schema_version = isset( $contract['snapshot_schema_version'] ) ? (int) $contract['snapshot_schema_version'] : 1; |
| 154 |
$schema_version = 2 === $schema_version ? 2 : 1; |
| 155 |
$profile = 2 === $schema_version && isset( $contract['observation_profile'] ) ? Sanitizer::slug( $contract['observation_profile'], 48 ) : ''; |
| 156 |
$revision = $this->payload_revision( $adapter ); |
| 157 |
$pending = $this->reconcile_pending_identity( $adapter, $revision ); |
| 158 |
$timestamp = time() + (int) $this->state->get( 'clock_offset', 0 ); |
| 159 |
if ( '' === $pending ) { |
| 160 |
$sequence = max( 1, (int) $this->state->get( 'last_acknowledged_sequence', 0 ) + 1 ); |
| 161 |
$body = array( |
| 162 |
'schema_version' => $schema_version, |
| 163 |
'sdk_version' => self::SDK_VERSION, |
| 164 |
'product' => $adapter->product_slug(), |
| 165 |
'device_id' => $this->identity->device_id(), |
| 166 |
'install_id' => $adapter->install_id(), |
| 167 |
); |
| 168 |
if ( 2 === $schema_version ) { |
| 169 |
$body['site_id'] = $this->site_identity->site_id(); |
| 170 |
$body['observation_profile'] = $profile; |
| 171 |
} |
| 172 |
$body['sequence'] = $sequence; |
| 173 |
$body['observed_at'] = $timestamp; |
| 174 |
$body['payload'] = $payload; |
| 175 |
$pending = (string) wp_json_encode( $body ); |
| 176 |
$this->state->set_many( |
| 177 |
array( |
| 178 |
'pending_sequence' => $sequence, |
| 179 |
'pending_body' => $pending, |
| 180 |
'pending_body_hash' => hash( 'sha256', $pending ), |
| 181 |
'pending_sdk_version' => self::SDK_VERSION, |
| 182 |
'pending_product_version' => $adapter->product_version(), |
| 183 |
'pending_payload_revision' => $revision, |
| 184 |
) |
| 185 |
); |
| 186 |
} |
| 187 |
|
| 188 |
$was_quarantined = '' !== (string) $this->state->get( 'pending_quarantine_class', '' ); |
| 189 |
if ( $was_quarantined ) { |
| 190 |
$this->state->set( 'pending_quarantine_probe_at', time() + DAY_IN_SECONDS + random_int( 0, 3600 ) ); |
| 191 |
} |
| 192 |
|
| 193 |
$secret = self::base64url_decode( (string) $this->state->get( 'credential_secret', '' ) ); |
| 194 |
if ( false === $secret || 32 !== strlen( $secret ) ) { |
| 195 |
return array( |
| 196 |
'ok' => false, |
| 197 |
'class' => 'invalid_credential', |
| 198 |
'status' => 0, |
| 199 |
'permanent' => false, |
| 200 |
); |
| 201 |
} |
| 202 |
$signature = self::base64url( hash_hmac( 'sha256', $timestamp . "\n" . hash( 'sha256', $pending ), $secret, true ) ); |
| 203 |
$response = $this->post( |
| 204 |
'/signals/v2/snapshot', |
| 205 |
$pending, |
| 206 |
array( |
| 207 |
'X-Signls-Credential' => (string) $this->state->get( 'credential_id', '' ), |
| 208 |
'X-Signls-Timestamp' => (string) $timestamp, |
| 209 |
'X-Signls-Signature' => 'v1=' . $signature, |
| 210 |
) |
| 211 |
); |
| 212 |
|
| 213 |
if ( $response['ok'] ) { |
| 214 |
$data = $response['data']; |
| 215 |
$sequence = (int) $this->state->get( 'pending_sequence', 0 ); |
| 216 |
if ( empty( $data['accepted'] ) || (int) ( isset( $data['sequence'] ) ? $data['sequence'] : 0 ) !== $sequence ) { |
| 217 |
$result = array( |
| 218 |
'ok' => false, |
| 219 |
'class' => 'invalid_response', |
| 220 |
'status' => $response['status'], |
| 221 |
'permanent' => true, |
| 222 |
); |
| 223 |
if ( $was_quarantined ) { |
| 224 |
$result['quarantined'] = true; |
| 225 |
} |
| 226 |
return $result; |
| 227 |
} |
| 228 |
$this->state->set_many( |
| 229 |
array( |
| 230 |
'last_acknowledged_sequence' => $sequence, |
| 231 |
'last_acknowledged_at' => (int) ( isset( $data['received_at'] ) ? $data['received_at'] : time() ), |
| 232 |
'last_success_at' => time(), |
| 233 |
'retry_attempt' => 0, |
| 234 |
) |
| 235 |
); |
| 236 |
$this->state->clear_pending(); |
| 237 |
return array( |
| 238 |
'ok' => true, |
| 239 |
'class' => ! empty( $data['duplicate'] ) ? 'duplicate' : 'accepted', |
| 240 |
'status' => $response['status'], |
| 241 |
'permanent' => false, |
| 242 |
); |
| 243 |
} |
| 244 |
|
| 245 |
if ( 'stale_timestamp' === $response['class'] && ! $clock_retry && isset( $response['data']['server_time'] ) && is_int( $response['data']['server_time'] ) && $response['data']['server_time'] > 0 ) { |
| 246 |
$response['server_time'] = (int) $response['data']['server_time']; |
| 247 |
} |
| 248 |
if ( 'sequence_conflict' === $response['class'] ) { |
| 249 |
$response['permanent'] = false; |
| 250 |
$expected = isset( $response['data']['expected_sequence'] ) && is_int( $response['data']['expected_sequence'] ) ? $response['data']['expected_sequence'] : 0; |
| 251 |
if ( ! $sequence_retry && $expected > 0 ) { |
| 252 |
$this->state->reconcile_sequence( $expected ); |
| 253 |
return $this->snapshot( $adapter, $payload, $clock_retry, true ); |
| 254 |
} |
| 255 |
} |
| 256 |
if ( ! empty( $response['permanent'] ) && in_array( $response['class'], self::QUARANTINE_CLASSES, true ) ) { |
| 257 |
return $this->quarantine( $response ); |
| 258 |
} |
| 259 |
if ( $was_quarantined ) { |
| 260 |
$response['quarantined'] = true; |
| 261 |
} |
| 262 |
return $response; |
| 263 |
} |
| 264 |
|
| 265 |
private function post( string $path, string $body, array $headers ): array { |
| 266 |
$endpoint = $this->endpoint(); |
| 267 |
if ( '' === $endpoint ) { |
| 268 |
return array( |
| 269 |
'ok' => false, |
| 270 |
'class' => 'invalid_endpoint', |
| 271 |
'status' => 0, |
| 272 |
'permanent' => true, |
| 273 |
); |
| 274 |
} |
| 275 |
|
| 276 |
$headers['Content-Type'] = 'application/json'; |
| 277 |
$response = wp_remote_post( |
| 278 |
$endpoint . $path, |
| 279 |
array( |
| 280 |
'body' => $body, |
| 281 |
'headers' => $headers, |
| 282 |
'timeout' => 10, |
| 283 |
'redirection' => 0, |
| 284 |
'blocking' => true, |
| 285 |
) |
| 286 |
); |
| 287 |
|
| 288 |
if ( is_wp_error( $response ) ) { |
| 289 |
$error_code = $response->get_error_code(); |
| 290 |
$error_code = is_scalar( $error_code ) ? substr( (string) $error_code, 0, 191 ) : ''; |
| 291 |
return array( |
| 292 |
'ok' => false, |
| 293 |
'class' => self::transport_class( $error_code ), |
| 294 |
'status' => 0, |
| 295 |
'permanent' => false, |
| 296 |
); |
| 297 |
} |
| 298 |
|
| 299 |
$status = (int) wp_remote_retrieve_response_code( $response ); |
| 300 |
$raw = (string) wp_remote_retrieve_body( $response ); |
| 301 |
$data = json_decode( $raw, true ); |
| 302 |
$data = is_array( $data ) ? $data : array(); |
| 303 |
if ( in_array( $status, array( 200, 201, 202 ), true ) ) { |
| 304 |
return array( |
| 305 |
'ok' => true, |
| 306 |
'class' => 'success', |
| 307 |
'status' => $status, |
| 308 |
'data' => $data, |
| 309 |
'permanent' => false, |
| 310 |
); |
| 311 |
} |
| 312 |
|
| 313 |
$code = Sanitizer::slug( isset( $data['code'] ) ? $data['code'] : '', 48, 'http_' . $status ); |
| 314 |
$transient = in_array( $status, array( 408, 425, 429 ), true ) || $status >= 500; |
| 315 |
return array( |
| 316 |
'ok' => false, |
| 317 |
'class' => $code, |
| 318 |
'status' => $status, |
| 319 |
'data' => $data, |
| 320 |
'permanent' => ! $transient, |
| 321 |
); |
| 322 |
} |
| 323 |
|
| 324 |
private function endpoint(): string { |
| 325 |
$endpoint = self::DEFAULT_ENDPOINT; |
| 326 |
if ( function_exists( 'apply_filters' ) ) { |
| 327 |
$endpoint = (string) apply_filters( 'signls_sdk_v1_endpoint', $endpoint, $this->state->product() ); |
| 328 |
} |
| 329 |
$endpoint = untrailingslashit( $endpoint ); |
| 330 |
$parts = wp_parse_url( $endpoint ); |
| 331 |
$host = isset( $parts['host'] ) ? strtolower( $parts['host'] ) : ''; |
| 332 |
$scheme = isset( $parts['scheme'] ) ? strtolower( $parts['scheme'] ) : ''; |
| 333 |
$local = 'localhost' === $host || '.test' === substr( $host, -5 ); |
| 334 |
return ( 'https' === $scheme || ( 'http' === $scheme && $local ) ) ? $endpoint : ''; |
| 335 |
} |
| 336 |
|
| 337 |
private function finish( array $result ): array { |
| 338 |
$values = array( |
| 339 |
'last_attempt_finished_at' => time(), |
| 340 |
'last_http_status' => (int) ( isset( $result['status'] ) ? $result['status'] : 0 ), |
| 341 |
); |
| 342 |
if ( $result['ok'] ) { |
| 343 |
$this->state->delete_keys( array( 'failure_class', 'next_retry_at' ) ); |
| 344 |
$this->state->set_many( $values ); |
| 345 |
return $result; |
| 346 |
} |
| 347 |
$values['failure_class'] = Sanitizer::slug( isset( $result['class'] ) ? $result['class'] : '', 48, 'unknown' ); |
| 348 |
if ( ! empty( $result['quarantined'] ) ) { |
| 349 |
$values['retry_attempt'] = 0; |
| 350 |
$this->state->delete_keys( array( 'next_retry_at' ) ); |
| 351 |
$this->state->set_many( $values ); |
| 352 |
return $result; |
| 353 |
} |
| 354 |
$attempt = (int) $this->state->get( 'retry_attempt', 0 ); |
| 355 |
$values['retry_attempt'] = $attempt + 1; |
| 356 |
if ( in_array( $values['failure_class'], array( 'invalid_credential', 'device_already_enrolled' ), true ) ) { |
| 357 |
$last_rotation = (int) $this->state->get( 'last_device_rotation_at', 0 ); |
| 358 |
if ( time() - $last_rotation >= DAY_IN_SECONDS ) { |
| 359 |
$this->identity->rotate_device(); |
| 360 |
$values['last_device_rotation_at'] = time(); |
| 361 |
} |
| 362 |
$result['permanent'] = false; |
| 363 |
} |
| 364 |
if ( empty( $result['permanent'] ) ) { |
| 365 |
$values['next_retry_at'] = time() + self::retry_delay( $attempt ) + random_int( 0, 300 ); |
| 366 |
} |
| 367 |
$this->state->set_many( $values ); |
| 368 |
return $result; |
| 369 |
} |
| 370 |
|
| 371 |
private function payload_revision( ProductAdapterInterface $adapter ): int { |
| 372 |
$contract = $adapter->contract(); |
| 373 |
$revision = isset( $contract['snapshot_payload_revision'] ) ? (int) $contract['snapshot_payload_revision'] : 1; |
| 374 |
return $revision > 0 ? $revision : 1; |
| 375 |
} |
| 376 |
|
| 377 |
private function pending_observed_at_is_future( int $server_time ): bool { |
| 378 |
$pending = json_decode( (string) $this->state->get( 'pending_body', '' ), true ); |
| 379 |
return is_array( $pending ) |
| 380 |
&& isset( $pending['observed_at'] ) |
| 381 |
&& is_int( $pending['observed_at'] ) |
| 382 |
&& $pending['observed_at'] > $server_time + self::CLOCK_SKEW_SECONDS; |
| 383 |
} |
| 384 |
|
| 385 |
private function reconcile_pending_identity( ProductAdapterInterface $adapter, int $revision ): string { |
| 386 |
$pending = (string) $this->state->get( 'pending_body', '' ); |
| 387 |
if ( '' === $pending ) { |
| 388 |
return ''; |
| 389 |
} |
| 390 |
if ( |
| 391 |
self::SDK_VERSION !== (string) $this->state->get( 'pending_sdk_version', '' ) |
| 392 |
|| $adapter->product_version() !== (string) $this->state->get( 'pending_product_version', '' ) |
| 393 |
|| $revision !== (int) $this->state->get( 'pending_payload_revision', 1 ) |
| 394 |
) { |
| 395 |
$this->state->clear_pending(); |
| 396 |
return ''; |
| 397 |
} |
| 398 |
return $pending; |
| 399 |
} |
| 400 |
|
| 401 |
private function quarantine( array $response ): array { |
| 402 |
$now = time(); |
| 403 |
$probe_at = (int) $this->state->get( 'pending_quarantine_probe_at', 0 ); |
| 404 |
if ( $probe_at <= $now ) { |
| 405 |
$probe_at = $now + DAY_IN_SECONDS + random_int( 0, 3600 ); |
| 406 |
} |
| 407 |
$quarantined_at = (int) $this->state->get( 'pending_quarantined_at', 0 ); |
| 408 |
$this->state->set_many( |
| 409 |
array( |
| 410 |
'pending_quarantine_class' => Sanitizer::slug( $response['class'], 48, 'contract_violation' ), |
| 411 |
'pending_quarantine_status' => (int) $response['status'], |
| 412 |
'pending_quarantined_at' => $quarantined_at > 0 ? $quarantined_at : $now, |
| 413 |
'pending_quarantine_probe_at' => $probe_at, |
| 414 |
'retry_attempt' => 0, |
| 415 |
) |
| 416 |
); |
| 417 |
$this->state->delete_keys( array( 'next_retry_at' ) ); |
| 418 |
$response['permanent'] = true; |
| 419 |
$response['quarantined'] = true; |
| 420 |
return $response; |
| 421 |
} |
| 422 |
|
| 423 |
private static function transport_class( string $code ): string { |
| 424 |
$code = strtolower( $code ); |
| 425 |
if ( false !== strpos( $code, 'resolve' ) || false !== strpos( $code, 'dns' ) ) { |
| 426 |
return 'transport_dns'; |
| 427 |
} |
| 428 |
if ( false !== strpos( $code, 'ssl' ) || false !== strpos( $code, 'tls' ) ) { |
| 429 |
return 'transport_tls'; |
| 430 |
} |
| 431 |
if ( false !== strpos( $code, 'timeout' ) ) { |
| 432 |
return 'transport_timeout'; |
| 433 |
} |
| 434 |
return 'transport_connect'; |
| 435 |
} |
| 436 |
|
| 437 |
private static function base64url( string $value ): string { |
| 438 |
return rtrim( strtr( base64_encode( $value ), '+/', '-_' ), '=' ); |
| 439 |
} |
| 440 |
|
| 441 |
private static function base64url_decode( string $value ) { |
| 442 |
if ( '' === $value || 1 !== preg_match( '/^[A-Za-z0-9_-]+$/', $value ) ) { |
| 443 |
return false; |
| 444 |
} |
| 445 |
$padding = ( 4 - strlen( $value ) % 4 ) % 4; |
| 446 |
return base64_decode( strtr( $value, '-_', '+/' ) . str_repeat( '=', $padding ), true ); |
| 447 |
} |
| 448 |
} |
| 449 |
|
