449 lines
14 KiB
PHP
449 lines
14 KiB
PHP
<?php
|
|
/**
|
|
* ActivityPub HTTP Class.
|
|
*
|
|
* @package Activitypub
|
|
*/
|
|
|
|
namespace Activitypub;
|
|
|
|
use Activitypub\Collection\Actors;
|
|
|
|
/**
|
|
* ActivityPub HTTP Class
|
|
*
|
|
* @author Matthias Pfefferle
|
|
*/
|
|
class Http {
|
|
/**
|
|
* Send a POST Request with the needed HTTP Headers
|
|
*
|
|
* @param string $url The URL endpoint.
|
|
* @param string $body The Post Body.
|
|
* @param int|null $user_id The WordPress User-ID, or null to sign with the Application key.
|
|
*
|
|
* @return array|\WP_Error The POST Response or an WP_Error.
|
|
*/
|
|
public static function post( $url, $body, $user_id ) {
|
|
/**
|
|
* Fires before an HTTP POST request is made.
|
|
*
|
|
* @param string $url The URL endpoint.
|
|
* @param string $body The POST body.
|
|
* @param int|null $user_id The WordPress User ID, or null when signing with the Application key.
|
|
*/
|
|
\do_action( 'activitypub_pre_http_post', $url, $body, $user_id );
|
|
|
|
/**
|
|
* Filters the HTTP headers user agent string.
|
|
*
|
|
* @param string $user_agent The user agent string.
|
|
* @param string $url The request URL.
|
|
*/
|
|
$user_agent = \apply_filters( 'http_headers_useragent', 'WordPress/' . get_masked_wp_version() . '; ' . \get_bloginfo( 'url' ), $url );
|
|
|
|
/**
|
|
* Filters the timeout duration for remote POST requests in ActivityPub.
|
|
*
|
|
* @param int $timeout The timeout value in seconds. Default 10 seconds.
|
|
*/
|
|
$timeout = \apply_filters( 'activitypub_remote_post_timeout', 10 );
|
|
|
|
/*
|
|
* Get the private key for signing the request. If a user ID is provided,
|
|
* get the user's private key; otherwise, use the application's private key.
|
|
*/
|
|
$private_key = null === $user_id ? Application::get_private_key() : Actors::get_private_key( $user_id );
|
|
|
|
$args = array(
|
|
'timeout' => $timeout,
|
|
'limit_response_size' => 1048576,
|
|
'redirection' => 3,
|
|
'user-agent' => "$user_agent; ActivityPub",
|
|
'headers' => array(
|
|
'Accept' => 'application/activity+json',
|
|
'Content-Type' => 'application/activity+json',
|
|
'Date' => \gmdate( 'D, d M Y H:i:s T' ),
|
|
),
|
|
'body' => $body,
|
|
'key_id' => \json_decode( $body )->actor . '#main-key',
|
|
'private_key' => $private_key,
|
|
'user_id' => $user_id,
|
|
);
|
|
|
|
$response = \wp_safe_remote_post( $url, $args );
|
|
$code = \wp_remote_retrieve_response_code( $response );
|
|
|
|
if ( $code >= 400 ) {
|
|
$response = new \WP_Error(
|
|
$code,
|
|
\__( 'Failed HTTP Request', 'activitypub' ),
|
|
array(
|
|
'status' => $code,
|
|
'response' => $response,
|
|
)
|
|
);
|
|
}
|
|
|
|
/**
|
|
* Action to save the response of the remote POST request.
|
|
*
|
|
* @param array|\WP_Error $response The response of the remote POST request.
|
|
* @param string $url The URL endpoint.
|
|
* @param string $body The Post Body.
|
|
* @param int|null $user_id The WordPress User-ID, or null when signing with the Application key.
|
|
*/
|
|
\do_action( 'activitypub_safe_remote_post_response', $response, $url, $body, $user_id );
|
|
|
|
return $response;
|
|
}
|
|
|
|
/**
|
|
* Send a GET Request with the needed HTTP Headers.
|
|
*
|
|
* @param string $url The URL endpoint.
|
|
* @param array $args Optional. Additional arguments to customize the request.
|
|
* - 'headers': Array of headers to override defaults.
|
|
* @param bool|int $cached Optional. Whether to cache the response, or the cache duration in seconds for
|
|
* successful responses. Failed responses use a fixed short backoff duration. Default false.
|
|
*
|
|
* @return array|\WP_Error The GET Response or a WP_Error.
|
|
*/
|
|
public static function get( $url, $args = array(), $cached = false ) {
|
|
// Backward compatibility: if $args is boolean/int, it's the old $cached parameter.
|
|
if ( ! \is_array( $args ) ) {
|
|
\_deprecated_argument(
|
|
__METHOD__,
|
|
'7.9.0',
|
|
\esc_html__( 'The $cached parameter should now be passed as the third argument.', 'activitypub' )
|
|
);
|
|
$cached = $args;
|
|
$args = array();
|
|
}
|
|
|
|
/**
|
|
* Fires before an HTTP GET request is made.
|
|
*
|
|
* @param string $url The URL endpoint.
|
|
*/
|
|
\do_action( 'activitypub_pre_http_get', $url );
|
|
|
|
$transient_key = self::generate_cache_key( $url );
|
|
|
|
// Check cache only if caching is requested.
|
|
if ( $cached ) {
|
|
$response = \get_transient( $transient_key );
|
|
|
|
if ( $response ) {
|
|
/**
|
|
* Action to save the response of the remote GET request.
|
|
*
|
|
* @param array|\WP_Error $response The response of the remote GET request.
|
|
* @param string $url The URL endpoint.
|
|
*/
|
|
\do_action( 'activitypub_safe_remote_get_response', $response, $url );
|
|
|
|
return $response;
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Filters the HTTP headers user agent string.
|
|
*
|
|
* @param string $user_agent The user agent string.
|
|
* @param string $url The request URL.
|
|
*/
|
|
$user_agent = \apply_filters( 'http_headers_useragent', 'WordPress/' . get_masked_wp_version() . '; ' . \get_bloginfo( 'url' ), $url );
|
|
|
|
/**
|
|
* Filters the timeout duration for remote GET requests in ActivityPub.
|
|
*
|
|
* @param int $timeout The timeout value in seconds. Default 10 seconds.
|
|
*/
|
|
$timeout = \apply_filters( 'activitypub_remote_get_timeout', 10 );
|
|
|
|
$defaults = array(
|
|
'timeout' => $timeout,
|
|
'limit_response_size' => 1048576,
|
|
'redirection' => 3,
|
|
'user-agent' => "$user_agent; ActivityPub",
|
|
'headers' => array(
|
|
'Accept' => 'application/activity+json',
|
|
'Content-Type' => 'application/activity+json',
|
|
'Date' => \gmdate( 'D, d M Y H:i:s T' ),
|
|
),
|
|
'key_id' => Application::get_key_id(),
|
|
'private_key' => Application::get_private_key(),
|
|
);
|
|
|
|
$args = \wp_parse_args( $args, $defaults );
|
|
$args['headers'] = \wp_parse_args( $args['headers'], $defaults['headers'] );
|
|
|
|
$response = \wp_safe_remote_get( $url, $args );
|
|
$code = \wp_remote_retrieve_response_code( $response );
|
|
|
|
if ( \is_wp_error( $response ) || $code >= 400 ) {
|
|
// Capture the served-from URL before $response is replaced by the error below.
|
|
$effective_url = \is_wp_error( $response ) ? '' : self::effective_url( $response );
|
|
|
|
if ( ! $code ) {
|
|
$code = 0;
|
|
}
|
|
$response = new \WP_Error( $code, \__( 'Failed HTTP Request', 'activitypub' ), array( 'status' => $code ) );
|
|
|
|
/*
|
|
* Cache errors to prevent repeated timeout waits, but never one reached via a
|
|
* cross-host redirect: cached under the requested URL's key, a one-off open
|
|
* redirect on the requested host would let a transient 4xx be replayed as a
|
|
* repeatable federation outage (the same caching concern as the success path
|
|
* below, just with a WP_Error instead of a document).
|
|
*
|
|
* - Retriable errors (timeouts, 5xx): 1 minute (server may recover quickly).
|
|
* - Other errors (4xx): 15 minutes (client errors are more permanent).
|
|
*/
|
|
if ( $cached && ( ! $effective_url || is_same_host( $url, $effective_url ) ) ) {
|
|
if ( \in_array( $code, ACTIVITYPUB_RETRY_ERROR_CODES, true ) || 0 === $code ) {
|
|
$cache_duration = MINUTE_IN_SECONDS;
|
|
} else {
|
|
$cache_duration = 15 * MINUTE_IN_SECONDS;
|
|
}
|
|
|
|
\set_transient( $transient_key, $response, $cache_duration );
|
|
}
|
|
|
|
return $response;
|
|
}
|
|
|
|
/**
|
|
* Action to save the response of the remote GET request.
|
|
*
|
|
* @param array|\WP_Error $response The response of the remote GET request.
|
|
* @param string $url The URL endpoint.
|
|
*/
|
|
\do_action( 'activitypub_safe_remote_get_response', $response, $url );
|
|
|
|
/*
|
|
* Never persist a response that was redirected to a different host. The cache
|
|
* is keyed on the requested URL, so caching cross-origin content under that key
|
|
* would let a one-off open redirect on the requested host durably associate the
|
|
* other host's document with that URL — a later lookup (e.g. a public-key fetch)
|
|
* would then return it. Same-host redirects (e.g. http→https) stay cacheable.
|
|
*/
|
|
$effective_url = self::effective_url( $response );
|
|
if ( $effective_url && ! is_same_host( $url, $effective_url ) ) {
|
|
return $response;
|
|
}
|
|
|
|
// Cache successful responses when caching is requested.
|
|
if ( $cached ) {
|
|
$cache_duration = $cached;
|
|
if ( ! \is_int( $cache_duration ) ) {
|
|
$cache_duration = HOUR_IN_SECONDS;
|
|
}
|
|
\set_transient( $transient_key, $response, $cache_duration );
|
|
}
|
|
|
|
return $response;
|
|
}
|
|
|
|
/**
|
|
* Check for URL for Tombstone.
|
|
*
|
|
* @param string $url The URL to check.
|
|
*
|
|
* @return bool True if the URL is a tombstone.
|
|
*/
|
|
public static function is_tombstone( $url ) {
|
|
\_deprecated_function( __METHOD__, '7.3.0', 'Activitypub\Tombstone::exists_remote' );
|
|
|
|
return Tombstone::exists_remote( $url );
|
|
}
|
|
|
|
/**
|
|
* Generate a cache key for the URL.
|
|
*
|
|
* @param string $url The URL to generate the cache key for.
|
|
*
|
|
* @return string The cache key.
|
|
*/
|
|
public static function generate_cache_key( $url ) {
|
|
return 'activitypub_http_' . \md5( $url );
|
|
}
|
|
|
|
/**
|
|
* Requests the Data from the Object-URL or Object-Array.
|
|
*
|
|
* Fetched objects are self-confirmed before they are returned, the same way
|
|
* Mastodon's `JsonLdHelper#fetch_resource` works: an object is trusted only when
|
|
* its own `id` is the URL it was actually served from (after any redirects). If
|
|
* the document served at the requested URL declares a different `id`, that id is
|
|
* dereferenced from its own host and accepted only when it self-confirms. This
|
|
* makes every caller safe to cache the result under its `id` — one host can never
|
|
* serve an object (and its public key) under another host's id — without each
|
|
* caller having to re-check the origin itself.
|
|
*
|
|
* @param array|string $url_or_object The Object or the Object URL.
|
|
* @param bool $cached Optional. Whether the result should be cached. Default true.
|
|
*
|
|
* @return array|\WP_Error The Object data as array or WP_Error on failure.
|
|
*/
|
|
public static function get_remote_object( $url_or_object, $cached = true ) {
|
|
/**
|
|
* Filters the preemptive return value of a remote object request.
|
|
*
|
|
* This is an explicit in-process override (used for caching and tests), not
|
|
* untrusted network data, so it is returned as-is without self-confirmation.
|
|
*
|
|
* @param array|string|null $response The response.
|
|
* @param array|string|null $url_or_object The Object or the Object URL.
|
|
*/
|
|
$response = \apply_filters( 'activitypub_pre_http_get_remote_object', null, $url_or_object );
|
|
if ( null !== $response ) {
|
|
return $response;
|
|
}
|
|
|
|
$url = object_to_uri( $url_or_object );
|
|
|
|
if ( Webfinger::is_acct( $url ) ) {
|
|
$url = Webfinger::resolve( $url );
|
|
}
|
|
|
|
if ( ! $url ) {
|
|
return new \WP_Error(
|
|
'activitypub_no_valid_actor_identifier',
|
|
\__( 'The "actor" identifier is not valid', 'activitypub' ),
|
|
array(
|
|
'status' => 404,
|
|
'object' => $url,
|
|
)
|
|
);
|
|
}
|
|
|
|
if ( \is_wp_error( $url ) ) {
|
|
return $url;
|
|
}
|
|
|
|
$final_url = '';
|
|
$object = self::fetch_object( $url, $cached, $final_url );
|
|
|
|
if ( \is_wp_error( $object ) ) {
|
|
return $object;
|
|
}
|
|
|
|
// Trust the document when it is served under its own id (after redirects).
|
|
if ( id_matches_url( $object, $final_url ) ) {
|
|
return $object;
|
|
}
|
|
|
|
$declared_id = isset( $object['id'] ) && \is_string( $object['id'] ) ? $object['id'] : '';
|
|
|
|
/*
|
|
* An id-less object cannot be cached under an id, so it cannot be written
|
|
* under another id in an id-keyed cache. Return the document as served.
|
|
*/
|
|
if ( '' === $declared_id ) {
|
|
return $object;
|
|
}
|
|
|
|
// Re-fetch the declared id from its own host and require it to self-confirm. One hop only.
|
|
$object = self::fetch_object( $declared_id, $cached, $final_url );
|
|
|
|
if ( \is_wp_error( $object ) ) {
|
|
return $object;
|
|
}
|
|
|
|
if ( ! id_matches_url( $object, $final_url ) ) {
|
|
return new \WP_Error(
|
|
'activitypub_object_id_mismatch',
|
|
\__( 'The object id does not match the URL it was served from', 'activitypub' ),
|
|
array( 'status' => 400 )
|
|
);
|
|
}
|
|
|
|
return $object;
|
|
}
|
|
|
|
/**
|
|
* Fetch and JSON-decode a single remote document.
|
|
*
|
|
* @param string $url The URL to fetch. Must already be resolved (not a WebFinger acct).
|
|
* @param bool $cached Whether the result may be served from and written to cache.
|
|
* @param string $final_url Filled by reference with the URL the document was served from,
|
|
* after following any redirects.
|
|
*
|
|
* @return array|\WP_Error The decoded document, or WP_Error on failure.
|
|
*/
|
|
private static function fetch_object( $url, $cached, &$final_url ) {
|
|
$final_url = $url;
|
|
|
|
if ( ! \wp_http_validate_url( $url ) ) {
|
|
return new \WP_Error(
|
|
'activitypub_no_valid_object_url',
|
|
\__( 'The "object" is/has no valid URL', 'activitypub' ),
|
|
array(
|
|
'status' => 400,
|
|
'object' => $url,
|
|
)
|
|
);
|
|
}
|
|
|
|
$response = self::get( $url, array(), $cached );
|
|
|
|
if ( \is_wp_error( $response ) ) {
|
|
return $response;
|
|
}
|
|
|
|
$effective_url = self::effective_url( $response );
|
|
if ( $effective_url ) {
|
|
$final_url = $effective_url;
|
|
}
|
|
|
|
$data = \json_decode( \wp_remote_retrieve_body( $response ), true );
|
|
|
|
if ( ! $data ) {
|
|
return new \WP_Error(
|
|
'activitypub_invalid_json',
|
|
\__( 'No valid JSON data', 'activitypub' ),
|
|
array(
|
|
'status' => 400,
|
|
'object' => $url,
|
|
)
|
|
);
|
|
}
|
|
|
|
return $data;
|
|
}
|
|
|
|
/**
|
|
* Extract the effective URL a response was served from, after redirects.
|
|
*
|
|
* WordPress follows redirects transparently and exposes the final URL only on
|
|
* the underlying Requests response object. Returns an empty string when the URL
|
|
* cannot be determined, so callers fall back to the URL they requested.
|
|
*
|
|
* SECURITY: the redirect protections that build on this (the self-confirmation in
|
|
* get_remote_object() and the cross-host cache skip in get()) fail OPEN when this
|
|
* returns an empty string — self-confirmation then compares against the requested
|
|
* URL, which a redirect could have bounced away from. This relies on the internal
|
|
* `http_response` → Requests response `url` shape; if a future WordPress release
|
|
* changes it, re-verify that this still returns the post-redirect URL.
|
|
*
|
|
* @param array $response A `wp_remote_get()` response array.
|
|
*
|
|
* @return string The final URL, or an empty string when unavailable.
|
|
*/
|
|
private static function effective_url( $response ) {
|
|
if ( empty( $response['http_response'] ) || ! \is_object( $response['http_response'] ) ) {
|
|
return '';
|
|
}
|
|
|
|
$requests_response = $response['http_response']->get_response_object();
|
|
|
|
if ( ! \is_object( $requests_response ) || empty( $requests_response->url ) ) {
|
|
return '';
|
|
}
|
|
|
|
return (string) $requests_response->url;
|
|
}
|
|
}
|