wp/wp-includes/https-detection.php
changeset 18 be944660c56a
child 19 3d72ae0968f4
equal deleted inserted replaced
17:34716fd837a4 18:be944660c56a
       
     1 <?php
       
     2 /**
       
     3  * HTTPS detection functions.
       
     4  *
       
     5  * @package WordPress
       
     6  * @since 5.7.0
       
     7  */
       
     8 
       
     9 /**
       
    10  * Checks whether the website is using HTTPS.
       
    11  *
       
    12  * This is based on whether both the home and site URL are using HTTPS.
       
    13  *
       
    14  * @since 5.7.0
       
    15  * @see wp_is_home_url_using_https()
       
    16  * @see wp_is_site_url_using_https()
       
    17  *
       
    18  * @return bool True if using HTTPS, false otherwise.
       
    19  */
       
    20 function wp_is_using_https() {
       
    21 	if ( ! wp_is_home_url_using_https() ) {
       
    22 		return false;
       
    23 	}
       
    24 
       
    25 	return wp_is_site_url_using_https();
       
    26 }
       
    27 
       
    28 /**
       
    29  * Checks whether the current site URL is using HTTPS.
       
    30  *
       
    31  * @since 5.7.0
       
    32  * @see home_url()
       
    33  *
       
    34  * @return bool True if using HTTPS, false otherwise.
       
    35  */
       
    36 function wp_is_home_url_using_https() {
       
    37 	return 'https' === wp_parse_url( home_url(), PHP_URL_SCHEME );
       
    38 }
       
    39 
       
    40 /**
       
    41  * Checks whether the current site's URL where WordPress is stored is using HTTPS.
       
    42  *
       
    43  * This checks the URL where WordPress application files (e.g. wp-blog-header.php or the wp-admin/ folder)
       
    44  * are accessible.
       
    45  *
       
    46  * @since 5.7.0
       
    47  * @see site_url()
       
    48  *
       
    49  * @return bool True if using HTTPS, false otherwise.
       
    50  */
       
    51 function wp_is_site_url_using_https() {
       
    52 	// Use direct option access for 'siteurl' and manually run the 'site_url'
       
    53 	// filter because `site_url()` will adjust the scheme based on what the
       
    54 	// current request is using.
       
    55 	/** This filter is documented in wp-includes/link-template.php */
       
    56 	$site_url = apply_filters( 'site_url', get_option( 'siteurl' ), '', null, null );
       
    57 
       
    58 	return 'https' === wp_parse_url( $site_url, PHP_URL_SCHEME );
       
    59 }
       
    60 
       
    61 /**
       
    62  * Checks whether HTTPS is supported for the server and domain.
       
    63  *
       
    64  * @since 5.7.0
       
    65  *
       
    66  * @return bool True if HTTPS is supported, false otherwise.
       
    67  */
       
    68 function wp_is_https_supported() {
       
    69 	$https_detection_errors = get_option( 'https_detection_errors' );
       
    70 
       
    71 	// If option has never been set by the Cron hook before, run it on-the-fly as fallback.
       
    72 	if ( false === $https_detection_errors ) {
       
    73 		wp_update_https_detection_errors();
       
    74 
       
    75 		$https_detection_errors = get_option( 'https_detection_errors' );
       
    76 	}
       
    77 
       
    78 	// If there are no detection errors, HTTPS is supported.
       
    79 	return empty( $https_detection_errors );
       
    80 }
       
    81 
       
    82 /**
       
    83  * Runs a remote HTTPS request to detect whether HTTPS supported, and stores potential errors.
       
    84  *
       
    85  * This internal function is called by a regular Cron hook to ensure HTTPS support is detected and maintained.
       
    86  *
       
    87  * @since 5.7.0
       
    88  * @access private
       
    89  */
       
    90 function wp_update_https_detection_errors() {
       
    91 	/**
       
    92 	 * Short-circuits the process of detecting errors related to HTTPS support.
       
    93 	 *
       
    94 	 * Returning a `WP_Error` from the filter will effectively short-circuit the default logic of trying a remote
       
    95 	 * request to the site over HTTPS, storing the errors array from the returned `WP_Error` instead.
       
    96 	 *
       
    97 	 * @since 5.7.0
       
    98 	 *
       
    99 	 * @param null|WP_Error $pre Error object to short-circuit detection,
       
   100 	 *                           or null to continue with the default behavior.
       
   101 	 */
       
   102 	$support_errors = apply_filters( 'pre_wp_update_https_detection_errors', null );
       
   103 	if ( is_wp_error( $support_errors ) ) {
       
   104 		update_option( 'https_detection_errors', $support_errors->errors );
       
   105 		return;
       
   106 	}
       
   107 
       
   108 	$support_errors = new WP_Error();
       
   109 
       
   110 	$response = wp_remote_request(
       
   111 		home_url( '/', 'https' ),
       
   112 		array(
       
   113 			'headers'   => array(
       
   114 				'Cache-Control' => 'no-cache',
       
   115 			),
       
   116 			'sslverify' => true,
       
   117 		)
       
   118 	);
       
   119 
       
   120 	if ( is_wp_error( $response ) ) {
       
   121 		$unverified_response = wp_remote_request(
       
   122 			home_url( '/', 'https' ),
       
   123 			array(
       
   124 				'headers'   => array(
       
   125 					'Cache-Control' => 'no-cache',
       
   126 				),
       
   127 				'sslverify' => false,
       
   128 			)
       
   129 		);
       
   130 
       
   131 		if ( is_wp_error( $unverified_response ) ) {
       
   132 			$support_errors->add(
       
   133 				'https_request_failed',
       
   134 				__( 'HTTPS request failed.' )
       
   135 			);
       
   136 		} else {
       
   137 			$support_errors->add(
       
   138 				'ssl_verification_failed',
       
   139 				__( 'SSL verification failed.' )
       
   140 			);
       
   141 		}
       
   142 
       
   143 		$response = $unverified_response;
       
   144 	}
       
   145 
       
   146 	if ( ! is_wp_error( $response ) ) {
       
   147 		if ( 200 !== wp_remote_retrieve_response_code( $response ) ) {
       
   148 			$support_errors->add( 'bad_response_code', wp_remote_retrieve_response_message( $response ) );
       
   149 		} elseif ( false === wp_is_local_html_output( wp_remote_retrieve_body( $response ) ) ) {
       
   150 			$support_errors->add( 'bad_response_source', __( 'It looks like the response did not come from this site.' ) );
       
   151 		}
       
   152 	}
       
   153 
       
   154 	update_option( 'https_detection_errors', $support_errors->errors );
       
   155 }
       
   156 
       
   157 /**
       
   158  * Schedules the Cron hook for detecting HTTPS support.
       
   159  *
       
   160  * @since 5.7.0
       
   161  * @access private
       
   162  */
       
   163 function wp_schedule_https_detection() {
       
   164 	if ( wp_installing() ) {
       
   165 		return;
       
   166 	}
       
   167 
       
   168 	if ( ! wp_next_scheduled( 'wp_https_detection' ) ) {
       
   169 		wp_schedule_event( time(), 'twicedaily', 'wp_https_detection' );
       
   170 	}
       
   171 }
       
   172 
       
   173 /**
       
   174  * Disables SSL verification if the 'cron_request' arguments include an HTTPS URL.
       
   175  *
       
   176  * This prevents an issue if HTTPS breaks, where there would be a failed attempt to verify HTTPS.
       
   177  *
       
   178  * @since 5.7.0
       
   179  * @access private
       
   180  *
       
   181  * @param array $request The Cron request arguments.
       
   182  * @return array $request The filtered Cron request arguments.
       
   183  */
       
   184 function wp_cron_conditionally_prevent_sslverify( $request ) {
       
   185 	if ( 'https' === wp_parse_url( $request['url'], PHP_URL_SCHEME ) ) {
       
   186 		$request['args']['sslverify'] = false;
       
   187 	}
       
   188 	return $request;
       
   189 }
       
   190 
       
   191 /**
       
   192  * Checks whether a given HTML string is likely an output from this WordPress site.
       
   193  *
       
   194  * This function attempts to check for various common WordPress patterns whether they are included in the HTML string.
       
   195  * Since any of these actions may be disabled through third-party code, this function may also return null to indicate
       
   196  * that it was not possible to determine ownership.
       
   197  *
       
   198  * @since 5.7.0
       
   199  * @access private
       
   200  *
       
   201  * @param string $html Full HTML output string, e.g. from a HTTP response.
       
   202  * @return bool|null True/false for whether HTML was generated by this site, null if unable to determine.
       
   203  */
       
   204 function wp_is_local_html_output( $html ) {
       
   205 	// 1. Check if HTML includes the site's Really Simple Discovery link.
       
   206 	if ( has_action( 'wp_head', 'rsd_link' ) ) {
       
   207 		$pattern = preg_replace( '#^https?:(?=//)#', '', esc_url( site_url( 'xmlrpc.php?rsd', 'rpc' ) ) ); // See rsd_link().
       
   208 		return false !== strpos( $html, $pattern );
       
   209 	}
       
   210 
       
   211 	// 2. Check if HTML includes the site's Windows Live Writer manifest link.
       
   212 	if ( has_action( 'wp_head', 'wlwmanifest_link' ) ) {
       
   213 		// Try both HTTPS and HTTP since the URL depends on context.
       
   214 		$pattern = preg_replace( '#^https?:(?=//)#', '', includes_url( 'wlwmanifest.xml' ) ); // See wlwmanifest_link().
       
   215 		return false !== strpos( $html, $pattern );
       
   216 	}
       
   217 
       
   218 	// 3. Check if HTML includes the site's REST API link.
       
   219 	if ( has_action( 'wp_head', 'rest_output_link_wp_head' ) ) {
       
   220 		// Try both HTTPS and HTTP since the URL depends on context.
       
   221 		$pattern = preg_replace( '#^https?:(?=//)#', '', esc_url( get_rest_url() ) ); // See rest_output_link_wp_head().
       
   222 		return false !== strpos( $html, $pattern );
       
   223 	}
       
   224 
       
   225 	// Otherwise the result cannot be determined.
       
   226 	return null;
       
   227 }