<?php

/**

 * HTTP API: WP_Http_Streams class

 *

 * @package WordPress

 * @subpackage HTTP

 * @since 4.4.0

 */

/**

 * Core class used to integrate PHP Streams as an HTTP transport.

 *

 * @since 2.7.0

 * @since 3.7.0 Combined with the fsockopen transport and switched to `stream_socket_client()`.

 */

class WP_Http_Streams {

	/**

	 * Send a HTTP request to a URI using PHP Streams.

	 *

	 * @see WP_Http::request For default options descriptions.

	 *

	 * @since 2.7.0

	 * @since 3.7.0 Combined with the fsockopen transport and switched to stream_socket_client().

	 *

	 * @param string $url The request URL.

	 * @param string|array $args Optional. Override the defaults.

	 * @return array|WP_Error Array containing 'headers', 'body', 'response', 'cookies', 'filename'. A WP_Error instance upon error

	 */

	public function request( $url, $args = array() ) {

		$defaults = array(

			'method'      => 'GET',

			'timeout'     => 5,

			'redirection' => 5,

			'httpversion' => '1.0',

			'blocking'    => true,

			'headers'     => array(),

			'body'        => null,

			'cookies'     => array(),

		);

		$r = wp_parse_args( $args, $defaults );

		if ( isset( $r['headers']['User-Agent'] ) ) {

			$r['user-agent'] = $r['headers']['User-Agent'];

			unset( $r['headers']['User-Agent'] );

		} elseif ( isset( $r['headers']['user-agent'] ) ) {

			$r['user-agent'] = $r['headers']['user-agent'];

			unset( $r['headers']['user-agent'] );

		}

		// Construct Cookie: header if any cookies are set.

		WP_Http::buildCookieHeader( $r );

		$arrURL = parse_url( $url );

		$connect_host = $arrURL['host'];

		$secure_transport = ( $arrURL['scheme'] == 'ssl' || $arrURL['scheme'] == 'https' );

		if ( ! isset( $arrURL['port'] ) ) {

			if ( $arrURL['scheme'] == 'ssl' || $arrURL['scheme'] == 'https' ) {

				$arrURL['port']   = 443;

				$secure_transport = true;

			} else {

				$arrURL['port'] = 80;

			}

		}

		// Always pass a Path, defaulting to the root in cases such as http://example.com

		if ( ! isset( $arrURL['path'] ) ) {

			$arrURL['path'] = '/';

		}

		if ( isset( $r['headers']['Host'] ) || isset( $r['headers']['host'] ) ) {

			if ( isset( $r['headers']['Host'] ) ) {

				$arrURL['host'] = $r['headers']['Host'];

			} else {

				$arrURL['host'] = $r['headers']['host'];

			}

			unset( $r['headers']['Host'], $r['headers']['host'] );

		}

		/*

		 * Certain versions of PHP have issues with 'localhost' and IPv6, It attempts to connect

		 * to ::1, which fails when the server is not set up for it. For compatibility, always

		 * connect to the IPv4 address.

		 */

		if ( 'localhost' == strtolower( $connect_host ) ) {

			$connect_host = '127.0.0.1';

		}

		$connect_host = $secure_transport ? 'ssl://' . $connect_host : 'tcp://' . $connect_host;

		$is_local   = isset( $r['local'] ) && $r['local'];

		$ssl_verify = isset( $r['sslverify'] ) && $r['sslverify'];

		if ( $is_local ) {

			/**

			 * Filters whether SSL should be verified for local requests.

			 *

			 * @since 2.8.0

			 * @since 5.1.0 The `$url` parameter was added.

			 *

			 * @param bool   $ssl_verify Whether to verify the SSL connection. Default true.

			 * @param string $url        The request URL.

			 */

			$ssl_verify = apply_filters( 'https_local_ssl_verify', $ssl_verify, $url );

		} elseif ( ! $is_local ) {

			/** This filter is documented in wp-includes/class-http.php */

			$ssl_verify = apply_filters( 'https_ssl_verify', $ssl_verify, $url );

		}

		$proxy = new WP_HTTP_Proxy();

		$context = stream_context_create(

			array(

				'ssl' => array(

					'verify_peer'       => $ssl_verify,

					//'CN_match' => $arrURL['host'], // This is handled by self::verify_ssl_certificate()

					'capture_peer_cert' => $ssl_verify,

					'SNI_enabled'       => true,

					'cafile'            => $r['sslcertificates'],

					'allow_self_signed' => ! $ssl_verify,

				),

			)

		);

		$timeout         = (int) floor( $r['timeout'] );

		$utimeout        = $timeout == $r['timeout'] ? 0 : 1000000 * $r['timeout'] % 1000000;

		$connect_timeout = max( $timeout, 1 );

		// Store error number.

		$connection_error = null;

		// Store error string.

		$connection_error_str = null;

		if ( ! WP_DEBUG ) {

			// In the event that the SSL connection fails, silence the many PHP Warnings.

			if ( $secure_transport ) {

				$error_reporting = error_reporting( 0 );

			}

			if ( $proxy->is_enabled() && $proxy->send_through_proxy( $url ) ) {

				$handle = @stream_socket_client( 'tcp://' . $proxy->host() . ':' . $proxy->port(), $connection_error, $connection_error_str, $connect_timeout, STREAM_CLIENT_CONNECT, $context );

			} else {

				$handle = @stream_socket_client( $connect_host . ':' . $arrURL['port'], $connection_error, $connection_error_str, $connect_timeout, STREAM_CLIENT_CONNECT, $context );

			}

			if ( $secure_transport ) {

				error_reporting( $error_reporting );

			}

		} else {

			if ( $proxy->is_enabled() && $proxy->send_through_proxy( $url ) ) {

				$handle = stream_socket_client( 'tcp://' . $proxy->host() . ':' . $proxy->port(), $connection_error, $connection_error_str, $connect_timeout, STREAM_CLIENT_CONNECT, $context );

			} else {

				$handle = stream_socket_client( $connect_host . ':' . $arrURL['port'], $connection_error, $connection_error_str, $connect_timeout, STREAM_CLIENT_CONNECT, $context );

			}

		}

		if ( false === $handle ) {

			// SSL connection failed due to expired/invalid cert, or, OpenSSL configuration is broken.

			if ( $secure_transport && 0 === $connection_error && '' === $connection_error_str ) {

				return new WP_Error( 'http_request_failed', __( 'The SSL certificate for the host could not be verified.' ) );

			}

			return new WP_Error( 'http_request_failed', $connection_error . ': ' . $connection_error_str );

		}

		// Verify that the SSL certificate is valid for this request.

		if ( $secure_transport && $ssl_verify && ! $proxy->is_enabled() ) {

			if ( ! self::verify_ssl_certificate( $handle, $arrURL['host'] ) ) {

				return new WP_Error( 'http_request_failed', __( 'The SSL certificate for the host could not be verified.' ) );

			}

		}

		stream_set_timeout( $handle, $timeout, $utimeout );

		if ( $proxy->is_enabled() && $proxy->send_through_proxy( $url ) ) { //Some proxies require full URL in this field.

			$requestPath = $url;

		} else {

			$requestPath = $arrURL['path'] . ( isset( $arrURL['query'] ) ? '?' . $arrURL['query'] : '' );

		}

		$strHeaders = strtoupper( $r['method'] ) . ' ' . $requestPath . ' HTTP/' . $r['httpversion'] . "\r\n";

		$include_port_in_host_header = (

			( $proxy->is_enabled() && $proxy->send_through_proxy( $url ) ) ||

			( 'http' == $arrURL['scheme'] && 80 != $arrURL['port'] ) ||

			( 'https' == $arrURL['scheme'] && 443 != $arrURL['port'] )

		);

		if ( $include_port_in_host_header ) {

			$strHeaders .= 'Host: ' . $arrURL['host'] . ':' . $arrURL['port'] . "\r\n";

		} else {

			$strHeaders .= 'Host: ' . $arrURL['host'] . "\r\n";

		}

		if ( isset( $r['user-agent'] ) ) {

			$strHeaders .= 'User-agent: ' . $r['user-agent'] . "\r\n";

		}

		if ( is_array( $r['headers'] ) ) {

			foreach ( (array) $r['headers'] as $header => $headerValue ) {

				$strHeaders .= $header . ': ' . $headerValue . "\r\n";

			}

		} else {

			$strHeaders .= $r['headers'];

		}

		if ( $proxy->use_authentication() ) {

			$strHeaders .= $proxy->authentication_header() . "\r\n";

		}

		$strHeaders .= "\r\n";

		if ( ! is_null( $r['body'] ) ) {

			$strHeaders .= $r['body'];

		}

		fwrite( $handle, $strHeaders );

		if ( ! $r['blocking'] ) {

			stream_set_blocking( $handle, 0 );

			fclose( $handle );

			return array(

				'headers'  => array(),

				'body'     => '',

				'response' => array(

					'code'    => false,

					'message' => false,

				),

				'cookies'  => array(),

			);

		}

		$strResponse  = '';

		$bodyStarted  = false;

		$keep_reading = true;

		$block_size   = 4096;

		if ( isset( $r['limit_response_size'] ) ) {

			$block_size = min( $block_size, $r['limit_response_size'] );

		}

		// If streaming to a file setup the file handle.

		if ( $r['stream'] ) {

			if ( ! WP_DEBUG ) {

				$stream_handle = @fopen( $r['filename'], 'w+' );

			} else {

				$stream_handle = fopen( $r['filename'], 'w+' );

			}

			if ( ! $stream_handle ) {

				return new WP_Error(

					'http_request_failed',

					sprintf(

						/* translators: 1: fopen(), 2: file name */

						__( 'Could not open handle for %1$s to %2$s.' ),

						'fopen()',

						$r['filename']

					)

				);

			}

			$bytes_written = 0;

			while ( ! feof( $handle ) && $keep_reading ) {

				$block = fread( $handle, $block_size );

				if ( ! $bodyStarted ) {

					$strResponse .= $block;

					if ( strpos( $strResponse, "\r\n\r\n" ) ) {

						$process     = WP_Http::processResponse( $strResponse );

						$bodyStarted = true;

						$block       = $process['body'];

						unset( $strResponse );

						$process['body'] = '';

					}

				}

				$this_block_size = strlen( $block );

				if ( isset( $r['limit_response_size'] ) && ( $bytes_written + $this_block_size ) > $r['limit_response_size'] ) {

					$this_block_size = ( $r['limit_response_size'] - $bytes_written );

					$block           = substr( $block, 0, $this_block_size );

				}

				$bytes_written_to_file = fwrite( $stream_handle, $block );

				if ( $bytes_written_to_file != $this_block_size ) {

					fclose( $handle );

					fclose( $stream_handle );

					return new WP_Error( 'http_request_failed', __( 'Failed to write request to temporary file.' ) );

				}

				$bytes_written += $bytes_written_to_file;

				$keep_reading = ! isset( $r['limit_response_size'] ) || $bytes_written < $r['limit_response_size'];

			}

			fclose( $stream_handle );

		} else {

			$header_length = 0;

			while ( ! feof( $handle ) && $keep_reading ) {

				$block        = fread( $handle, $block_size );

				$strResponse .= $block;

				if ( ! $bodyStarted && strpos( $strResponse, "\r\n\r\n" ) ) {

					$header_length = strpos( $strResponse, "\r\n\r\n" ) + 4;

					$bodyStarted   = true;

				}

				$keep_reading = ( ! $bodyStarted || ! isset( $r['limit_response_size'] ) || strlen( $strResponse ) < ( $header_length + $r['limit_response_size'] ) );

			}

			$process = WP_Http::processResponse( $strResponse );

			unset( $strResponse );

		}

		fclose( $handle );

		$arrHeaders = WP_Http::processHeaders( $process['headers'], $url );

		$response = array(

			'headers'  => $arrHeaders['headers'],

			// Not yet processed.

			'body'     => null,

			'response' => $arrHeaders['response'],

			'cookies'  => $arrHeaders['cookies'],

			'filename' => $r['filename'],

		);

		// Handle redirects.

		if ( false !== ( $redirect_response = WP_Http::handle_redirects( $url, $r, $response ) ) ) {

			return $redirect_response;

		}

		// If the body was chunk encoded, then decode it.

		if ( ! empty( $process['body'] ) && isset( $arrHeaders['headers']['transfer-encoding'] ) && 'chunked' == $arrHeaders['headers']['transfer-encoding'] ) {

			$process['body'] = WP_Http::chunkTransferDecode( $process['body'] );

		}

		if ( true === $r['decompress'] && true === WP_Http_Encoding::should_decode( $arrHeaders['headers'] ) ) {

			$process['body'] = WP_Http_Encoding::decompress( $process['body'] );

		}

		if ( isset( $r['limit_response_size'] ) && strlen( $process['body'] ) > $r['limit_response_size'] ) {

			$process['body'] = substr( $process['body'], 0, $r['limit_response_size'] );

		}

		$response['body'] = $process['body'];

		return $response;

	}

	/**

	 * Verifies the received SSL certificate against its Common Names and subjectAltName fields.

	 *

	 * PHP's SSL verifications only verify that it's a valid Certificate, it doesn't verify if

	 * the certificate is valid for the hostname which was requested.

	 * This function verifies the requested hostname against certificate's subjectAltName field,

	 * if that is empty, or contains no DNS entries, a fallback to the Common Name field is used.

	 *

	 * IP Address support is included if the request is being made to an IP address.

	 *

	 * @since 3.7.0

	 *

	 * @param stream $stream The PHP Stream which the SSL request is being made over

	 * @param string $host The hostname being requested

	 * @return bool If the cerficiate presented in $stream is valid for $host

	 */

	public static function verify_ssl_certificate( $stream, $host ) {

		$context_options = stream_context_get_options( $stream );

		if ( empty( $context_options['ssl']['peer_certificate'] ) ) {

			return false;

		}

		$cert = openssl_x509_parse( $context_options['ssl']['peer_certificate'] );

		if ( ! $cert ) {

			return false;

		}

		/*

		 * If the request is being made to an IP address, we'll validate against IP fields

		 * in the cert (if they exist)

		 */

		$host_type = ( WP_Http::is_ip_address( $host ) ? 'ip' : 'dns' );

		$certificate_hostnames = array();

		if ( ! empty( $cert['extensions']['subjectAltName'] ) ) {