<?php

/**

 * HTTP API: WP_Http_Curl class

 *

 * @package WordPress

 * @subpackage HTTP

 * @since 4.4.0

 */

/**

 * Core class used to integrate Curl as an HTTP transport.

 *

 * HTTP request method uses Curl extension to retrieve the url.

 *

 * Requires the Curl extension to be installed.

 *

 * @since 2.7.0

 */

class WP_Http_Curl {

	/**

	 * Temporary header storage for during requests.

	 *

	 * @since 3.2.0

	 * @var string

	 */

	private $headers = '';

	/**

	 * Temporary body storage for during requests.

	 *

	 * @since 3.6.0

	 * @var string

	 */

	private $body = '';

	/**

	 * The maximum amount of data to receive from the remote server.

	 *

	 * @since 3.6.0

	 * @var int

	 */

	private $max_body_length = false;

	/**

	 * The file resource used for streaming to file.

	 *

	 * @since 3.6.0

	 * @var resource

	 */

	private $stream_handle = false;

	/**

	 * The total bytes written in the current request.

	 *

	 * @since 4.1.0

	 * @var int

	 */

	private $bytes_written_total = 0;

	/**

	 * Send a HTTP request to a URI using cURL extension.

	 *

	 * @since 2.7.0

	 *

	 * @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 );

		$handle = curl_init();

		// cURL offers really easy proxy support.

		$proxy = new WP_HTTP_Proxy();

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

			curl_setopt( $handle, CURLOPT_PROXYTYPE, CURLPROXY_HTTP );

			curl_setopt( $handle, CURLOPT_PROXY, $proxy->host() );

			curl_setopt( $handle, CURLOPT_PROXYPORT, $proxy->port() );

			if ( $proxy->use_authentication() ) {

				curl_setopt( $handle, CURLOPT_PROXYAUTH, CURLAUTH_ANY );

				curl_setopt( $handle, CURLOPT_PROXYUSERPWD, $proxy->authentication() );

			}

		}

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

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

		if ( $is_local ) {

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

			$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 );

		}

		/*

		 * CURLOPT_TIMEOUT and CURLOPT_CONNECTTIMEOUT expect integers. Have to use ceil since.

		 * a value of 0 will allow an unlimited timeout.

		 */

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

		curl_setopt( $handle, CURLOPT_CONNECTTIMEOUT, $timeout );

		curl_setopt( $handle, CURLOPT_TIMEOUT, $timeout );

		curl_setopt( $handle, CURLOPT_URL, $url );

		curl_setopt( $handle, CURLOPT_RETURNTRANSFER, true );

		curl_setopt( $handle, CURLOPT_SSL_VERIFYHOST, ( $ssl_verify === true ) ? 2 : false );

		curl_setopt( $handle, CURLOPT_SSL_VERIFYPEER, $ssl_verify );

		if ( $ssl_verify ) {

			curl_setopt( $handle, CURLOPT_CAINFO, $r['sslcertificates'] );

		}

		curl_setopt( $handle, CURLOPT_USERAGENT, $r['user-agent'] );

		/*

		 * The option doesn't work with safe mode or when open_basedir is set, and there's

		 * a bug #17490 with redirected POST requests, so handle redirections outside Curl.

		 */

		curl_setopt( $handle, CURLOPT_FOLLOWLOCATION, false );

		if ( defined( 'CURLOPT_PROTOCOLS' ) ) { // PHP 5.2.10 / cURL 7.19.4

			curl_setopt( $handle, CURLOPT_PROTOCOLS, CURLPROTO_HTTP | CURLPROTO_HTTPS );

		}

		switch ( $r['method'] ) {

			case 'HEAD':

				curl_setopt( $handle, CURLOPT_NOBODY, true );

				break;

			case 'POST':

				curl_setopt( $handle, CURLOPT_POST, true );

				curl_setopt( $handle, CURLOPT_POSTFIELDS, $r['body'] );

				break;

			case 'PUT':

				curl_setopt( $handle, CURLOPT_CUSTOMREQUEST, 'PUT' );

				curl_setopt( $handle, CURLOPT_POSTFIELDS, $r['body'] );

				break;

			default:

				curl_setopt( $handle, CURLOPT_CUSTOMREQUEST, $r['method'] );

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

					curl_setopt( $handle, CURLOPT_POSTFIELDS, $r['body'] );

				}

				break;

		}

		if ( true === $r['blocking'] ) {

			curl_setopt( $handle, CURLOPT_HEADERFUNCTION, array( $this, 'stream_headers' ) );

			curl_setopt( $handle, CURLOPT_WRITEFUNCTION, array( $this, 'stream_body' ) );

		}

		curl_setopt( $handle, CURLOPT_HEADER, false );

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

			$this->max_body_length = intval( $r['limit_response_size'] );

		} else {

			$this->max_body_length = false;

		}

		// If streaming to a file open a file handle, and setup our curl streaming handler.

		if ( $r['stream'] ) {

			if ( ! WP_DEBUG ) {

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

			} else {

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

			}

			if ( ! $this->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']

					)

				);

			}

		} else {

			$this->stream_handle = false;

		}

		if ( ! empty( $r['headers'] ) ) {

			// cURL expects full header strings in each element.

			$headers = array();

			foreach ( $r['headers'] as $name => $value ) {

				$headers[] = "{$name}: $value";

			}

			curl_setopt( $handle, CURLOPT_HTTPHEADER, $headers );

		}

		if ( $r['httpversion'] == '1.0' ) {

			curl_setopt( $handle, CURLOPT_HTTP_VERSION, CURL_HTTP_VERSION_1_0 );

		} else {

			curl_setopt( $handle, CURLOPT_HTTP_VERSION, CURL_HTTP_VERSION_1_1 );

		}

		/**

		 * Fires before the cURL request is executed.

		 *

		 * Cookies are not currently handled by the HTTP API. This action allows

		 * plugins to handle cookies themselves.

		 *

		 * @since 2.8.0

		 *

		 * @param resource $handle  The cURL handle returned by curl_init() (passed by reference).

		 * @param array    $r       The HTTP request arguments.

		 * @param string   $url     The request URL.

		 */

		do_action_ref_array( 'http_api_curl', array( &$handle, $r, $url ) );

		// We don't need to return the body, so don't. Just execute request and return.

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

			curl_exec( $handle );

			if ( $curl_error = curl_error( $handle ) ) {

				curl_close( $handle );

				return new WP_Error( 'http_request_failed', $curl_error );

			}

			if ( in_array( curl_getinfo( $handle, CURLINFO_HTTP_CODE ), array( 301, 302 ) ) ) {

				curl_close( $handle );

				return new WP_Error( 'http_request_failed', __( 'Too many redirects.' ) );

			}

			curl_close( $handle );

			return array(

				'headers'  => array(),

				'body'     => '',

				'response' => array(

					'code'    => false,

					'message' => false,

				),

				'cookies'  => array(),

			);

		}

		curl_exec( $handle );

		$theHeaders          = WP_Http::processHeaders( $this->headers, $url );

		$theBody             = $this->body;

		$bytes_written_total = $this->bytes_written_total;

		$this->headers             = '';

		$this->body                = '';

		$this->bytes_written_total = 0;

		$curl_error = curl_errno( $handle );

		// If an error occurred, or, no response.

		if ( $curl_error || ( 0 == strlen( $theBody ) && empty( $theHeaders['headers'] ) ) ) {

			if ( CURLE_WRITE_ERROR /* 23 */ == $curl_error ) {

				if ( ! $this->max_body_length || $this->max_body_length != $bytes_written_total ) {

					if ( $r['stream'] ) {

						curl_close( $handle );

						fclose( $this->stream_handle );

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

					} else {

						curl_close( $handle );

						return new WP_Error( 'http_request_failed', curl_error( $handle ) );

					}

				}

			} else {

				if ( $curl_error = curl_error( $handle ) ) {

					curl_close( $handle );

					return new WP_Error( 'http_request_failed', $curl_error );

				}

			}

			if ( in_array( curl_getinfo( $handle, CURLINFO_HTTP_CODE ), array( 301, 302 ) ) ) {

				curl_close( $handle );

				return new WP_Error( 'http_request_failed', __( 'Too many redirects.' ) );

			}

		}

		curl_close( $handle );

		if ( $r['stream'] ) {

			fclose( $this->stream_handle );

		}

		$response = array(

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

			'body'     => null,

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

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

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

		);

		// Handle redirects.

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

			return $redirect_response;

		}

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

			$theBody = WP_Http_Encoding::decompress( $theBody );

		}

		$response['body'] = $theBody;

		return $response;

	}

	/**

	 * Grabs the headers of the cURL request.

	 *

	 * Each header is sent individually to this callback, so we append to the `$header` property

	 * for temporary storage

	 *

	 * @since 3.2.0

	 *

	 * @param resource $handle  cURL handle.

	 * @param string   $headers cURL request headers.

	 * @return int Length of the request headers.

	 */

	private function stream_headers( $handle, $headers ) {

		$this->headers .= $headers;

		return strlen( $headers );

	}

	/**

	 * Grabs the body of the cURL request.

	 *

	 * The contents of the document are passed in chunks, so we append to the `$body`

	 * property for temporary storage. Returning a length shorter than the length of

	 * `$data` passed in will cause cURL to abort the request with `CURLE_WRITE_ERROR`.

	 *

	 * @since 3.6.0

	 *

	 * @param resource $handle  cURL handle.

	 * @param string   $data    cURL request body.

	 * @return int Total bytes of data written.

	 */

	private function stream_body( $handle, $data ) {

		$data_length = strlen( $data );

		if ( $this->max_body_length && ( $this->bytes_written_total + $data_length ) > $this->max_body_length ) {

			$data_length = ( $this->max_body_length - $this->bytes_written_total );

			$data        = substr( $data, 0, $data_length );

		}

		if ( $this->stream_handle ) {

			$bytes_written = fwrite( $this->stream_handle, $data );

		} else {

			$this->body   .= $data;

			$bytes_written = $data_length;

		}

		$this->bytes_written_total += $bytes_written;

		// Upon event of this function returning less than strlen( $data ) curl will error with CURLE_WRITE_ERROR.

		return $bytes_written;

	}

	/**

	 * Determines whether this class can be used for retrieving a URL.

	 *

	 * @since 2.7.0

	 *

	 * @param array $args Optional. Array of request arguments. Default empty array.

	 * @return bool False means this class can not be used, true means it can.

	 */

	public static function test( $args = array() ) {

		if ( ! function_exists( 'curl_init' ) || ! function_exists( 'curl_exec' ) ) {

			return false;

		}

		$is_ssl = isset( $args['ssl'] ) && $args['ssl'];

		if ( $is_ssl ) {

			$curl_version = curl_version();

			// Check whether this cURL version support SSL requests.

			if ( ! ( CURL_VERSION_SSL & $curl_version['features'] ) ) {

				return false;

			}

		}

		/**

		 * Filters whether cURL can be used as a transport for retrieving a URL.

		 *

		 * @since 2.7.0

		 *

		 * @param bool  $use_class Whether the class can be used. Default true.

		 * @param array $args      An array of request arguments.

		 */

		return apply_filters( 'use_curl_transport', true, $args );

	}

}