class-wc-rest-authentication.php
<?php
/**
* REST API Authentication
*
* @package WooCommerce\RestApi
* @since 2.6.0
*/
defined( 'ABSPATH' ) || exit;
/**
* REST API authentication class.
*/
class WC_REST_Authentication {
/**
* Authentication error.
*
* @var WP_Error
*/
protected $error = null;
/**
* Logged in user data.
*
* @var stdClass
*/
protected $user = null;
/**
* Current auth method.
*
* @var string
*/
protected $auth_method = '';
/**
* Provides access to the global WC_REST_Authentication instance.
*
* @internal
* @return self
*/
public static function instance(): self {
static $instance;
if ( ! isset( $instance ) ) {
$instance = new self();
}
return $instance;
}
/**
* Initialize authentication actions.
*/
public function __construct() {
add_filter( 'determine_current_user', array( $this, 'authenticate' ), 15 );
add_filter( 'rest_authentication_errors', array( $this, 'authentication_fallback' ) );
add_filter( 'rest_authentication_errors', array( $this, 'check_authentication_error' ), 15 );
add_filter( 'rest_post_dispatch', array( $this, 'send_unauthorized_headers' ), 50 );
add_filter( 'rest_pre_dispatch', array( $this, 'check_user_permissions' ), 10, 3 );
}
/**
* Check if is request to our REST API.
*
* @return bool
*/
protected function is_request_to_rest_api() {
if ( empty( $_SERVER['REQUEST_URI'] ) ) {
return false;
}
$rest_prefix = trailingslashit( rest_get_url_prefix() );
$request_uri = esc_url_raw( wp_unslash( $_SERVER['REQUEST_URI'] ) );
// Check if the request is to the WC API endpoints.
$woocommerce = ( false !== strpos( $request_uri, $rest_prefix . 'wc/' ) );
// Allow third party plugins use our authentication methods.
$third_party = ( false !== strpos( $request_uri, $rest_prefix . 'wc-' ) );
return apply_filters( 'woocommerce_rest_is_request_to_rest_api', $woocommerce || $third_party );
}
/**
* Authenticate user.
*
* @param int|false $user_id User ID if one has been determined, false otherwise.
* @return int|false
*/
public function authenticate( $user_id ) {
// Do not authenticate twice and check if is a request to our endpoint in the WP REST API.
if ( ! empty( $user_id ) || ! $this->is_request_to_rest_api() ) {
return $user_id;
}
if ( is_ssl() ) {
$user_id = $this->perform_basic_authentication();
}
if ( $user_id ) {
return $user_id;
}
return $this->perform_oauth_authentication();
}
/**
* Authenticate the user if authentication wasn't performed during the
* determine_current_user action.
*
* Necessary in cases where wp_get_current_user() is called before WooCommerce is loaded.
*
* @see https://github.com/woocommerce/woocommerce/issues/26847
*
* @param WP_Error|null|bool $error Error data.
* @return WP_Error|null|bool
*/
public function authentication_fallback( $error ) {
if ( ! empty( $error ) ) {
// Another plugin has already declared a failure.
return $error;
}
if ( empty( $this->error ) && empty( $this->auth_method ) && empty( $this->user ) && 0 === get_current_user_id() ) {
// Authentication hasn't occurred during `determine_current_user`, so check auth.
$user_id = $this->authenticate( false );
if ( $user_id ) {
wp_set_current_user( $user_id );
return true;
}
}
return $error;
}
/**
* Check for authentication error.
*
* @param WP_Error|null|bool $error Error data.
* @return WP_Error|null|bool
*/
public function check_authentication_error( $error ) {
// Pass through other errors.
if ( ! empty( $error ) ) {
return $error;
}
return $this->get_error();
}
/**
* Set authentication error.
*
* @param WP_Error $error Authentication error data.
*/
protected function set_error( $error ) {
// Reset user.
$this->user = null;
$this->error = $error;
}
/**
* Get authentication error.
*
* @return WP_Error|null.
*/
protected function get_error() {
return $this->error;
}
/**
* Basic Authentication.
*
* SSL-encrypted requests are not subject to sniffing or man-in-the-middle
* attacks, so the request can be authenticated by simply looking up the user
* associated with the given consumer key and confirming the consumer secret
* provided is valid.
*
* @return int|bool
*/
private function perform_basic_authentication() {
$this->auth_method = 'basic_auth';
$consumer_key = '';
$consumer_secret = '';
// If the $_GET parameters are present, use those first.
if ( ! empty( $_GET['consumer_key'] ) && ! empty( $_GET['consumer_secret'] ) ) { // WPCS: CSRF ok.
$consumer_key = $_GET['consumer_key']; // WPCS: CSRF ok, sanitization ok.
$consumer_secret = $_GET['consumer_secret']; // WPCS: CSRF ok, sanitization ok.
}
// If the above is not present, we will do full basic auth.
if ( ! $consumer_key && ! empty( $_SERVER['PHP_AUTH_USER'] ) && ! empty( $_SERVER['PHP_AUTH_PW'] ) ) {
$consumer_key = $_SERVER['PHP_AUTH_USER']; // WPCS: CSRF ok, sanitization ok.
$consumer_secret = $_SERVER['PHP_AUTH_PW']; // WPCS: CSRF ok, sanitization ok.
}
// Stop if don't have any key.
if ( ! $consumer_key || ! $consumer_secret ) {
return false;
}
// Get user data.
$this->user = $this->get_user_data_by_consumer_key( $consumer_key );
if ( empty( $this->user ) ) {
return false;
}
// Validate user secret.
if ( ! hash_equals( $this->user->consumer_secret, $consumer_secret ) ) { // @codingStandardsIgnoreLine
$this->set_error( new WP_Error( 'woocommerce_rest_authentication_error', __( 'Consumer secret is invalid.', 'woocommerce' ), array( 'status' => 401 ) ) );
return false;
}
return $this->user->user_id;
}
/**
* Parse the Authorization header into parameters.
*
* @since 3.0.0
*
* @param string $header Authorization header value (not including "Authorization: " prefix).
*
* @return array Map of parameter values.
*/
public function parse_header( $header ) {
if ( 'OAuth ' !== substr( $header, 0, 6 ) ) {
return array();
}
// From OAuth PHP library, used under MIT license.
$params = array();
if ( preg_match_all( '/(oauth_[a-z_-]*)=(:?"([^"]*)"|([^,]*))/', $header, $matches ) ) {
foreach ( $matches[1] as $i => $h ) {
$params[ $h ] = urldecode( empty( $matches[3][ $i ] ) ? $matches[4][ $i ] : $matches[3][ $i ] );
}
if ( isset( $params['realm'] ) ) {
unset( $params['realm'] );
}
}
return $params;
}
/**
* Get the authorization header.
*
* On certain systems and configurations, the Authorization header will be
* stripped out by the server or PHP. Typically this is then used to
* generate `PHP_AUTH_USER`/`PHP_AUTH_PASS` but not passed on. We use
* `getallheaders` here to try and grab it out instead.
*
* @since 3.0.0
*
* @return string Authorization header if set.
*/
public function get_authorization_header() {
if ( ! empty( $_SERVER['HTTP_AUTHORIZATION'] ) ) {
return wp_unslash( $_SERVER['HTTP_AUTHORIZATION'] ); // WPCS: sanitization ok.
}
if ( function_exists( 'getallheaders' ) ) {
$headers = getallheaders();
// Check for the authoization header case-insensitively.
foreach ( $headers as $key => $value ) {
if ( 'authorization' === strtolower( $key ) ) {
return $value;
}
}
}
return '';
}
/**
* Get oAuth parameters from $_GET, $_POST or request header.
*
* @since 3.0.0
*
* @return array|WP_Error
*/
public function get_oauth_parameters() {
$params = array_merge( $_GET, $_POST ); // WPCS: CSRF ok.
$params = wp_unslash( $params );
$header = $this->get_authorization_header();
if ( ! empty( $header ) ) {
// Trim leading spaces.
$header = trim( $header );
$header_params = $this->parse_header( $header );
if ( ! empty( $header_params ) ) {
$params = array_merge( $params, $header_params );
}
}
$param_names = array(
'oauth_consumer_key',
'oauth_timestamp',
'oauth_nonce',
'oauth_signature',
'oauth_signature_method',
);
$errors = array();
$have_one = false;
// Check for required OAuth parameters.
foreach ( $param_names as $param_name ) {
if ( empty( $params[ $param_name ] ) ) {
$errors[] = $param_name;
} else {
$have_one = true;
}
}
// All keys are missing, so we're probably not even trying to use OAuth.
if ( ! $have_one ) {
return array();
}
// If we have at least one supplied piece of data, and we have an error,
// then it's a failed authentication.
if ( ! empty( $errors ) ) {
$message = sprintf(
/* translators: %s: amount of errors */
_n( 'Missing OAuth parameter %s', 'Missing OAuth parameters %s', count( $errors ), 'woocommerce' ),
implode( ', ', $errors )
);
$this->set_error( new WP_Error( 'woocommerce_rest_authentication_missing_parameter', $message, array( 'status' => 401 ) ) );
return array();
}
return $params;
}
/**
* Perform OAuth 1.0a "one-legged" (http://oauthbible.com/#oauth-10a-one-legged) authentication for non-SSL requests.
*
* This is required so API credentials cannot be sniffed or intercepted when making API requests over plain HTTP.
*
* This follows the spec for simple OAuth 1.0a authentication (RFC 5849) as closely as possible, with two exceptions:
*
* 1) There is no token associated with request/responses, only consumer keys/secrets are used.
*
* 2) The OAuth parameters are included as part of the request query string instead of part of the Authorization header,
* This is because there is no cross-OS function within PHP to get the raw Authorization header.
*
* @link http://tools.ietf.org/html/rfc5849 for the full spec.
*
* @return int|bool
*/
private function perform_oauth_authentication() {
$this->auth_method = 'oauth1';
$params = $this->get_oauth_parameters();
if ( empty( $params ) ) {
return false;
}
// Fetch WP user by consumer key.
$this->user = $this->get_user_data_by_consumer_key( $params['oauth_consumer_key'] );
if ( empty( $this->user ) ) {
$this->set_error( new WP_Error( 'woocommerce_rest_authentication_error', __( 'Consumer key is invalid.', 'woocommerce' ), array( 'status' => 401 ) ) );
return false;
}
// Perform OAuth validation.
$signature = $this->check_oauth_signature( $this->user, $params );
if ( is_wp_error( $signature ) ) {
$this->set_error( $signature );
return false;
}
$timestamp_and_nonce = $this->check_oauth_timestamp_and_nonce( $this->user, $params['oauth_timestamp'], $params['oauth_nonce'] );
if ( is_wp_error( $timestamp_and_nonce ) ) {
$this->set_error( $timestamp_and_nonce );
return false;
}
return $this->user->user_id;
}
/**
* Verify that the consumer-provided request signature matches our generated signature,
* this ensures the consumer has a valid key/secret.
*
* @param stdClass $user User data.
* @param array $params The request parameters.
* @return true|WP_Error
*/
private function check_oauth_signature( $user, $params ) {
$http_method = isset( $_SERVER['REQUEST_METHOD'] ) ? strtoupper( $_SERVER['REQUEST_METHOD'] ) : ''; // WPCS: sanitization ok.
$request_path = isset( $_SERVER['REQUEST_URI'] ) ? wp_parse_url( $_SERVER['REQUEST_URI'], PHP_URL_PATH ) : ''; // WPCS: sanitization ok.
$wp_base = get_home_url( null, '/', 'relative' );
if ( substr( $request_path, 0, strlen( $wp_base ) ) === $wp_base ) {
$request_path = substr( $request_path, strlen( $wp_base ) );
}
$base_request_uri = rawurlencode( get_home_url( null, $request_path, is_ssl() ? 'https' : 'http' ) );
// Get the signature provided by the consumer and remove it from the parameters prior to checking the signature.
$consumer_signature = rawurldecode( str_replace( ' ', '+', $params['oauth_signature'] ) );
unset( $params['oauth_signature'] );
// Sort parameters.
if ( ! uksort( $params, 'strcmp' ) ) {
return new WP_Error( 'woocommerce_rest_authentication_error', __( 'Invalid signature - failed to sort parameters.', 'woocommerce' ), array( 'status' => 401 ) );
}
// Normalize parameter key/values.
$params = $this->normalize_parameters( $params );
$query_string = implode( '%26', $this->join_with_equals_sign( $params ) ); // Join with ampersand.
$string_to_sign = $http_method . '&' . $base_request_uri . '&' . $query_string;
if ( 'HMAC-SHA1' !== $params['oauth_signature_method'] && 'HMAC-SHA256' !== $params['oauth_signature_method'] ) {
return new WP_Error( 'woocommerce_rest_authentication_error', __( 'Invalid signature - signature method is invalid.', 'woocommerce' ), array( 'status' => 401 ) );
}
$hash_algorithm = strtolower( str_replace( 'HMAC-', '', $params['oauth_signature_method'] ) );
$secret = $user->consumer_secret . '&';
$signature = base64_encode( hash_hmac( $hash_algorithm, $string_to_sign, $secret, true ) );
if ( ! hash_equals( $signature, $consumer_signature ) ) { // @codingStandardsIgnoreLine
return new WP_Error( 'woocommerce_rest_authentication_error', __( 'Invalid signature - provided signature does not match.', 'woocommerce' ), array( 'status' => 401 ) );
}
return true;
}
/**
* Creates an array of urlencoded strings out of each array key/value pairs.
*
* @param array $params Array of parameters to convert.
* @param array $query_params Array to extend.
* @param string $key Optional Array key to append.
* @return string Array of urlencoded strings.
*/
private function join_with_equals_sign( $params, $query_params = array(), $key = '' ) {
foreach ( $params as $param_key => $param_value ) {
if ( $key ) {
$param_key = $key . '%5B' . $param_key . '%5D'; // Handle multi-dimensional array.
}
if ( is_array( $param_value ) ) {
$query_params = $this->join_with_equals_sign( $param_value, $query_params, $param_key );
} else {
$string = $param_key . '=' . $param_value; // Join with equals sign.
$query_params[] = wc_rest_urlencode_rfc3986( $string );
}
}
return $query_params;
}
/**
* Normalize each parameter by assuming each parameter may have already been
* encoded, so attempt to decode, and then re-encode according to RFC 3986.
*
* Note both the key and value is normalized so a filter param like:
*
* 'filter[period]' => 'week'
*
* is encoded to:
*
* 'filter%255Bperiod%255D' => 'week'
*
* This conforms to the OAuth 1.0a spec which indicates the entire query string
* should be URL encoded.
*
* @see rawurlencode()
* @param array $parameters Un-normalized parameters.
* @return array Normalized parameters.
*/
private function normalize_parameters( $parameters ) {
$keys = wc_rest_urlencode_rfc3986( array_keys( $parameters ) );
$values = wc_rest_urlencode_rfc3986( array_values( $parameters ) );
$parameters = array_combine( $keys, $values );
return $parameters;
}
/**
* Verify that the timestamp and nonce provided with the request are valid. This prevents replay attacks where
* an attacker could attempt to re-send an intercepted request at a later time.
*
* - A timestamp is valid if it is within 15 minutes of now.
* - A nonce is valid if it has not been used within the last 15 minutes.
*
* @param stdClass $user User data.
* @param int $timestamp The unix timestamp for when the request was made.
* @param string $nonce A unique (for the given user) 32 alphanumeric string, consumer-generated.
* @return bool|WP_Error
*/
private function check_oauth_timestamp_and_nonce( $user, $timestamp, $nonce ) {
global $wpdb;
$valid_window = 15 * 60; // 15 minute window.
if ( ( $timestamp < time() - $valid_window ) || ( $timestamp > time() + $valid_window ) ) {
return new WP_Error( 'woocommerce_rest_authentication_error', __( 'Invalid timestamp.', 'woocommerce' ), array( 'status' => 401 ) );
}
$used_nonces = maybe_unserialize( $user->nonces );
if ( empty( $used_nonces ) ) {
$used_nonces = array();
}
if ( in_array( $nonce, $used_nonces, true ) ) {
return new WP_Error( 'woocommerce_rest_authentication_error', __( 'Invalid nonce - nonce has already been used.', 'woocommerce' ), array( 'status' => 401 ) );
}
$used_nonces[ $timestamp ] = $nonce;
// Remove expired nonces.
foreach ( $used_nonces as $nonce_timestamp => $nonce ) {
if ( $nonce_timestamp < ( time() - $valid_window ) ) {
unset( $used_nonces[ $nonce_timestamp ] );
}
}
$used_nonces = maybe_serialize( $used_nonces );
$wpdb->update(
$wpdb->prefix . 'woocommerce_api_keys',
array( 'nonces' => $used_nonces ),
array( 'key_id' => $user->key_id ),
array( '%s' ),
array( '%d' )
);
return true;
}
/**
* Return the user data for the given consumer_key.
*
* @param string $consumer_key Consumer key.
* @return array
*/
private function get_user_data_by_consumer_key( $consumer_key ) {
global $wpdb;
$consumer_key = wc_api_hash( sanitize_text_field( $consumer_key ) );
$user = $wpdb->get_row(
$wpdb->prepare(
"
SELECT key_id, user_id, permissions, consumer_key, consumer_secret, nonces
FROM {$wpdb->prefix}woocommerce_api_keys
WHERE consumer_key = %s
",
$consumer_key
)
);
return $user;
}
/**
* Check that the API keys provided have the proper key-specific permissions to either read or write API resources.
*
* @param string $method Request method.
* @return bool|WP_Error
*/
private function check_permissions( $method ) {
$permissions = $this->user->permissions;
switch ( $method ) {
case 'HEAD':
case 'GET':
if ( 'read' !== $permissions && 'read_write' !== $permissions ) {
return new WP_Error( 'woocommerce_rest_authentication_error', __( 'The API key provided does not have read permissions.', 'woocommerce' ), array( 'status' => 401 ) );
}
break;
case 'POST':
case 'PUT':
case 'PATCH':
case 'DELETE':
if ( 'write' !== $permissions && 'read_write' !== $permissions ) {
return new WP_Error( 'woocommerce_rest_authentication_error', __( 'The API key provided does not have write permissions.', 'woocommerce' ), array( 'status' => 401 ) );
}
break;
case 'OPTIONS':
return true;
default:
return new WP_Error( 'woocommerce_rest_authentication_error', __( 'Unknown request method.', 'woocommerce' ), array( 'status' => 401 ) );
}
return true;
}
/**
* Updates the `last_access` field for the API key associated with the current request.
*
* This method tries to disambiguate 'primary' API requests from any programmatic REST
* API requests made internally.
*
* @param WP_REST_Request $request The request currently being processed.
*
* @return void
*/
private function update_last_access( $request ) {
global $wp;
global $wpdb;
// Lots of (programmatically) created REST API requests may be handled within the same process.
// In most cases, however, we do not want to record the last access time for each of these.
$do_not_record = true;
// Try to detect if the REST API request actively being processed matches the current WP request.
if ( is_a( $wp, WP::class ) && is_a( $request, WP_REST_Request::class ) ) {
$actual_http_request = trim( $wp->request, '/' );
$api_request_in_progress = trim( $request->get_route(), '/' );
// Remove the REST API route prefix (normally 'wp-json') for easier comparison.
$rest_prefix = trailingslashit( rest_get_url_prefix() );
if ( str_starts_with( $actual_http_request, $rest_prefix ) ) {
$actual_http_request = substr( $actual_http_request, strlen( $rest_prefix ) );
}
// Recommend recording the last access time only if the actual WP request and the current
// API request being processed are a match.
$do_not_record = $actual_http_request !== $api_request_in_progress;
}
/**
* This filter enables the exclusion of the most recent access time from being logged for REST API calls.
*
* @param bool $result Default value.
* @param int $key_id Key ID associated with REST API request.
* @param int $user_id User ID associated with REST API request.
*
* @since 7.7.0
*/
if ( apply_filters( 'woocommerce_disable_rest_api_access_log', $do_not_record, $this->user->key_id, $this->user->user_id ) ) {
return;
}
$wpdb->update(
$wpdb->prefix . 'woocommerce_api_keys',
array( 'last_access' => current_time( 'mysql' ) ),
array( 'key_id' => $this->user->key_id ),
array( '%s' ),
array( '%d' )
);
}
/**
* If the consumer_key and consumer_secret $_GET parameters are NOT provided
* and the Basic auth headers are either not present or the consumer secret does not match the consumer
* key provided, then return the correct Basic headers and an error message.
*
* @param WP_REST_Response $response Current response being served.
* @return WP_REST_Response
*/
public function send_unauthorized_headers( $response ) {
if ( is_wp_error( $this->get_error() ) && 'basic_auth' === $this->auth_method ) {
$auth_message = __( 'WooCommerce API. Use a consumer key in the username field and a consumer secret in the password field.', 'woocommerce' );
$response->header( 'WWW-Authenticate', 'Basic realm="' . $auth_message . '"', true );
}
return $response;
}
/**
* Check for user permissions and register last access.
*
* @param mixed $result Response to replace the requested version with.
* @param WP_REST_Server $server Server instance.
* @param WP_REST_Request $request Request used to generate the response.
* @return mixed
*/
public function check_user_permissions( $result, $server, $request ) {
if ( $this->user ) {
// Check API Key permissions.
$allowed = $this->check_permissions( $request->get_method() );
if ( is_wp_error( $allowed ) ) {
return $allowed;
}
// Register last access.
$this->update_last_access( $request );
}
return $result;
}
}
WC_REST_Authentication::instance();
