CdnEngine_Ftp.php

<?php
/**
 * File: CdnEngine_CloudFront.php
 *
 * @package W3TC
 */

namespace W3TC;

define( 'W3TC_CDN_FTP_CONNECT_TIMEOUT', 30 );

/**
 * Class CdnEngine_Ftp
 *
 * W3 CDN FTP Class
 *
 * phpcs:disable PSR2.Classes.PropertyDeclaration.Underscore
 * phpcs:disable PSR2.Methods.MethodDeclaration.Underscore
 * phpcs:disable WordPress.PHP.NoSilencedErrors.Discouraged
 * phpcs:disable WordPress.WP.AlternativeFunctions
 */
class CdnEngine_Ftp extends CdnEngine_Base {
	/**
	 * FTP resource
	 *
	 * @var resource
	 */
	private $_ftp = null;

	/**
	 * Class constructor for initializing FTP/SFTP connection settings.
	 *
	 * @param array $config Optional configuration array to override default values.
	 *                      Keys include 'host', 'type', 'user', 'pass', 'default_keys',
	 *                      'pubkey', 'privkey', 'path', 'pasv', 'domain', and 'docroot'.
	 */
	public function __construct( $config = array() ) {
		$config = array_merge(
			array(
				'host'         => '',
				'type'         => '',
				'user'         => '',
				'pass'         => '',
				'default_keys' => false,
				'pubkey'       => '',
				'privkey'      => '',
				'path'         => '',
				'pasv'         => false,
				'domain'       => array(),
				'docroot'      => '',
			),
			$config
		);

		list( $ip, $port ) = Util_Content::endpoint_to_host_port( $config['host'], 21 );
		$config['host']    = $ip;
		$config['port']    = $port;

		if ( 'sftp' === $config['type'] && $config['default_keys'] ) {
			$home              = isset( $_SERVER['HOME'] ) ? sanitize_text_field( wp_unslash( $_SERVER['HOME'] ) ) : '';
			$config['pubkey']  = $home . '/.ssh/id_rsa.pub';
			$config['privkey'] = $home . '/.ssh/id_rsa';
		}

		parent::__construct( $config );
	}

	/**
	 * Establishes a connection to the FTP/SFTP server.
	 *
	 * Attempts to connect to the server using the configuration provided in the class.
	 * Handles both FTP and SFTP types with error handling and connection setup.
	 *
	 * @param string $error Reference to a variable to capture error messages.
	 *
	 * @return bool Returns true on successful connection, false on failure.
	 */
	public function _connect( &$error ) {
		if ( empty( $this->_config['host'] ) ) {
			$error = 'Empty host.';

			return false;
		}

		$this->_set_error_handler();

		if ( 'sftp' === $this->_config['type'] ) {
			if ( ! function_exists( 'ssh2_connect' ) ) {
				$error = sprintf( 'Missing required php-ssh2 extension.' );

				$this->_restore_error_handler();
				$this->_disconnect();

				return false;
			}

			$this->_ftp = @ssh2_connect( $this->_config['host'], (int) $this->_config['port'] );

			return $this->_connect_sftp( $error );
		}

		if ( 'ftps' === $this->_config['type'] ) {
			$this->_ftp = @ftp_ssl_connect( $this->_config['host'], (int) $this->_config['port'], W3TC_CDN_FTP_CONNECT_TIMEOUT );
		} else {
			$this->_ftp = @ftp_connect( $this->_config['host'], (int) $this->_config['port'], W3TC_CDN_FTP_CONNECT_TIMEOUT );
		}

		if ( ! $this->_ftp ) {
			$error = sprintf(
				'Unable to connect to %s:%d (%s).',
				$this->_config['host'],
				$this->_config['port'],
				$this->_get_last_error()
			);

			$this->_restore_error_handler();

			return false;
		}

		if ( ! @ftp_login( $this->_ftp, $this->_config['user'], $this->_config['pass'] ) ) {
			$error = sprintf( 'Incorrect login or password (%s).', $this->_get_last_error() );

			$this->_restore_error_handler();
			$this->_disconnect();

			return false;
		}

		if ( ! @ftp_pasv( $this->_ftp, $this->_config['pasv'] ) ) {
			$error = sprintf( 'Unable to change mode to passive (%s).', $this->_get_last_error() );

			$this->_restore_error_handler();
			$this->_disconnect();

			return false;
		}

		if ( ! empty( $this->_config['path'] ) && ! @ftp_chdir( $this->_ftp, $this->_config['path'] ) ) {
			$error = sprintf( 'Unable to change directory to: %s (%s).', $this->_config['path'], $this->_get_last_error() );

			$this->_restore_error_handler();
			$this->_disconnect();

			return false;
		}

		$this->_restore_error_handler();

		return true;
	}

	/**
	 * Establishes an SFTP connection and authenticates using the provided credentials.
	 *
	 * This method is used specifically for handling SFTP connections, including both
	 * public key and password-based authentication.
	 *
	 * @param string $error Reference to a variable to capture error messages.
	 *
	 * @return bool Returns true on successful connection, false on failure.
	 */
	public function _connect_sftp( &$error ) {
		if ( is_file( $this->_config['pass'] ) ) {
			if ( ! @ssh2_auth_pubkey_file( $this->_ftp, $this->_config['user'], $this->_config['pubkey'], $this->_config['privkey'], $this->_config['pass'] ) ) {
				$error = sprintf( 'Public key authentication failed (%s).', $this->_get_last_error() );

				$this->_restore_error_handler();
				$this->_disconnect();

				return false;
			}
		} elseif ( ! @ssh2_auth_password( $this->_ftp, $this->_config['user'], $this->_config['pass'] ) ) {
			$error = sprintf( 'Incorrect login or password (%s).', $this->_get_last_error() );

			$this->_restore_error_handler();
			$this->_disconnect();

			return false;
		}

		if ( ! empty( $this->_config['path'] ) && ! @ssh2_exec( $this->_ftp, 'cd ' . $this->_config['path'] ) ) {
			$error = sprintf( 'Unable to change directory to: %s (%s).', $this->_config['path'], $this->_get_last_error() );

			$this->_restore_error_handler();
			$this->_disconnect();

			return false;
		}

		$this->_restore_error_handler();

		return true;
	}

	/**
	 * Closes the current FTP/SFTP connection.
	 *
	 * This method properly terminates the connection to the server based on the connection type.
	 *
	 * @return void
	 */
	public function _disconnect() {
		if ( 'sftp' === $this->_config['type'] ) {
			if ( function_exists( 'ssh2_connect' ) ) {
				@ssh2_exec( $this->_ftp, 'echo "EXITING" && exit;' );
				$this->_ftp = null;
			}
		} else {
			@ftp_close( $this->_ftp );
		}
	}

	/**
	 * Sends an MDTM (Modification Time) command to the FTP server to update the modification time of a file.
	 *
	 * This method is used for updating the timestamp of a remote file.
	 *
	 * @param string $remote_file The remote file path to modify.
	 * @param int    $mtime       The modification time to set for the file.
	 *
	 * @return array Returns the raw response from the FTP server.
	 */
	public function _mdtm( $remote_file, $mtime ) {
		$command = sprintf( 'MDTM %s %s', gmdate( 'YmdHis', $mtime ), $remote_file );

		return @ftp_raw( $this->_ftp, $command );
	}

	/**
	 * Uploads files to the FTP/SFTP server.
	 *
	 * Handles the upload of files, including checking for existing files and handling
	 * overwrites, directory creation, and error logging.
	 *
	 * @param array    $files        Array of files to upload, with 'local_path' and 'remote_path' for each file.
	 * @param array    $results      Array to capture the results of the upload attempt.
	 * @param bool     $force_rewrite Whether to force overwriting files even if they are up-to-date.
	 * @param int|null $timeout_time Optional timeout time to stop the process if exceeded.
	 *
	 * @return bool Returns true if the upload is successful, false if there were errors.
	 */
	public function upload( $files, &$results, $force_rewrite = false, $timeout_time = null ) {
		$error = null;

		if ( ! $this->_connect( $error ) ) {
			$results = $this->_get_results( $files, W3TC_CDN_RESULT_HALT, $error );

			return false;
		}

		$this->_set_error_handler();

		if ( 'sftp' === $this->_config['type'] ) {
			return $this->_upload_sftp( $files, $results, $force_rewrite, $timeout_time );
		}

		$home = @ftp_pwd( $this->_ftp );

		if ( false === $home ) {
			$results = $this->_get_results( $files, W3TC_CDN_RESULT_HALT, sprintf( 'Unable to get current directory (%s).', $this->_get_last_error() ) );

			$this->_restore_error_handler();
			$this->_disconnect();

			return false;
		}

		foreach ( $files as $file ) {
			$local_path  = $file['local_path'];
			$remote_path = $file['remote_path'];

			// process at least one item before timeout so that progress goes on.
			if ( ! empty( $results ) ) {
				if ( ! is_null( $timeout_time ) && time() > $timeout_time ) {
					return 'timeout';
				}
			}

			if ( ! file_exists( $local_path ) ) {
				$results[] = $this->_get_result(
					$local_path,
					$remote_path,
					W3TC_CDN_RESULT_ERROR,
					'Source file not found.',
					$file
				);

				continue;
			}

			@ftp_chdir( $this->_ftp, $home );

			$remote_dir  = dirname( $remote_path );
			$remote_dirs = preg_split( '~\\/+~', $remote_dir );

			foreach ( $remote_dirs as $dir ) {
				if ( ! @ftp_chdir( $this->_ftp, $dir ) ) {
					if ( ! @ftp_mkdir( $this->_ftp, $dir ) ) {
						$results[] = $this->_get_result(
							$local_path,
							$remote_path,
							W3TC_CDN_RESULT_ERROR,
							sprintf( 'Unable to create directory (%s).', $this->_get_last_error() ),
							$file
						);

						continue 2;
					}

					if ( ! @ftp_chdir( $this->_ftp, $dir ) ) {
						$results[] = $this->_get_result(
							$local_path,
							$remote_path,
							W3TC_CDN_RESULT_ERROR,
							sprintf( 'Unable to change directory (%s).', $this->_get_last_error() ),
							$file
						);

						continue 2;
					}
				}
			}

			// basename cannot be used, kills chinese chars and similar characters.
			$remote_file = substr( $remote_path, strrpos( $remote_path, '/' ) + 1 );

			$mtime = @filemtime( $local_path );

			if ( ! $force_rewrite ) {
				$size      = @filesize( $local_path );
				$ftp_size  = @ftp_size( $this->_ftp, $remote_file );
				$ftp_mtime = @ftp_mdtm( $this->_ftp, $remote_file );

				if ( $size === $ftp_size && $mtime === $ftp_mtime ) {
					$results[] = $this->_get_result(
						$local_path,
						$remote_path,
						W3TC_CDN_RESULT_OK,
						'File up-to-date.',
						$file
					);

					continue;
				}
			}

			$result = @ftp_put( $this->_ftp, $remote_file, $local_path, FTP_BINARY );

			if ( $result ) {
				$this->_mdtm( $remote_file, $mtime );

				$results[] = $this->_get_result(
					$local_path,
					$remote_path,
					W3TC_CDN_RESULT_OK,
					'OK',
					$file
				);
			} else {
				$results[] = $this->_get_result(
					$local_path,
					$remote_path,
					W3TC_CDN_RESULT_ERROR,
					sprintf( 'Unable to upload file (%s).', $this->_get_last_error() ),
					$file
				);
			}
		}

		$this->_restore_error_handler();
		$this->_disconnect();

		return ! $this->_is_error( $results );
	}

	/**
	 * Handles the SFTP-specific file upload process.
	 *
	 * This method is called when the connection type is SFTP, and is responsible for
	 * uploading files using the SFTP protocol, including directory creation and file transfer.
	 *
	 * @param array    $files         Array of files to upload, with 'local_path' and 'remote_path' for each file.
	 * @param array    $results       Array to capture the results of the upload attempt.
	 * @param bool     $force_rewrite Whether to force overwriting files even if they are up-to-date.
	 * @param int|null $timeout_time  Optional timeout time to stop the process if exceeded.
	 *
	 * @return string Returns 'timeout' if the process times out, otherwise no return value on success.
	 */
	public function _upload_sftp( $files, $results, $force_rewrite, $timeout_time ) {
		$sftp = ssh2_sftp( $this->_ftp );

		foreach ( $files as $file ) {
			$local_path  = $file['local_path'];
			$remote_path = $file['remote_path'];

			// process at least one item before timeout so that progress goes on.
			if ( ! empty( $results ) ) {
				if ( ! is_null( $timeout_time ) && time() > $timeout_time ) {
					return 'timeout';
				}
			}

			if ( ! file_exists( $local_path ) ) {
				$results[] = $this->_get_result(
					$local_path,
					$remote_path,
					W3TC_CDN_RESULT_ERROR,
					'Source file not found.',
					$file
				);

				continue;
			}

			$remote_dir = dirname( $remote_path );

			if ( ! @file_exists( 'ssh2.sftp://' . intval( $sftp ) . $remote_dir ) ) {
				if ( ! @ssh2_sftp_mkdir( $sftp, $remote_dir, null, true ) ) {
					$results[] = $this->_get_result(
						$local_path,
						$remote_path,
						W3TC_CDN_RESULT_ERROR,
						sprintf( 'Unable to create directory (%s).', $this->_get_last_error() ),
						$file
					);

					continue;
				}
			}

			$mtime = @filemtime( $local_path );

			if ( ! $force_rewrite ) {
				$size     = @filesize( $local_path );
				$statinfo = @ssh2_sftp_stat( $sftp, $remote_path );

				if ( $size === $statinfo['size'] && $mtime === $statinfo['mtime'] ) {
					$results[] = $this->_get_result(
						$local_path,
						$remote_path,
						W3TC_CDN_RESULT_OK,
						'File up-to-date.',
						$file
					);

					continue;
				}
			}

			$result = @ssh2_scp_send( $this->_ftp, $local_path, $remote_path );

			if ( $result ) {
				$results[] = $this->_get_result(
					$local_path,
					$remote_path,
					W3TC_CDN_RESULT_OK,
					'OK',
					$file
				);
			} else {
				$results[] = $this->_get_result(
					$local_path,
					$remote_path,
					W3TC_CDN_RESULT_ERROR,
					sprintf( 'Unable to upload file (%s).', $this->_get_last_error() ),
					$file
				);
			}
		}

		$this->_restore_error_handler();
		$this->_disconnect();

		return ! $this->_is_error( $results );
	}

	/**
	 * Deletes the specified files from the remote FTP/SFTP server.
	 *
	 * This method connects to the remote server, attempts to delete each file, and then tries to remove
	 * the directories associated with those files. It collects the results of the delete operations
	 * and stores them in the results array.
	 *
	 * @param array $files   An array of file data, where each entry contains the local and remote paths of the files.
	 * @param array $results An array that will be populated with the results of each delete operation.
	 *
	 * @return bool Returns true if all files and directories were deleted successfully, otherwise false.
	 */
	public function delete( $files, &$results ) {
		$error = null;

		if ( ! $this->_connect( $error ) ) {
			$results = $this->_get_results( $files, W3TC_CDN_RESULT_HALT, $error );

			return false;
		}

		$this->_set_error_handler();

		foreach ( $files as $file ) {
			$local_path  = $file['local_path'];
			$remote_path = $file['remote_path'];

			if ( 'sftp' === $this->_config['type'] ) {
				$sftp   = @ssh2_sftp( $this->_ftp );
				$result = @ssh2_sftp_unlink( $sftp, $remote_path );
			} else {
				$result = @ftp_delete( $this->_ftp, $remote_path );
			}

			if ( $result ) {
				$results[] = $this->_get_result(
					$local_path,
					$remote_path,
					W3TC_CDN_RESULT_OK,
					'OK',
					$file
				);
			} else {
				$results[] = $this->_get_result(
					$local_path,
					$remote_path,
					W3TC_CDN_RESULT_ERROR,
					sprintf( 'Unable to delete file (%s).', $this->_get_last_error() ),
					$file
				);
			}

			while ( true ) {
				$remote_path = dirname( $remote_path );

				if ( '.' === $remote_path ) {
					break;
				}

				if ( 'sftp' === $this->_config['type'] && ! @ssh2_sftp_rmdir( $sftp, $remote_path ) ) {
					break;
				} elseif ( ! @ftp_rmdir( $this->_ftp, $remote_path ) ) {
					break;
				}
			}
		}

		$this->_restore_error_handler();
		$this->_disconnect();

		return ! $this->_is_error( $results );
	}

	/**
	 * Tests the FTP/SFTP connection and upload/download functionality.
	 *
	 * This method tests the FTP/SFTP connection by performing a series of file operations including
	 * creating a temporary directory, uploading a test file, deleting it, and cleaning up. If any step
	 * fails, an error message is returned via the $error parameter.
	 *
	 * @param string $error A reference to a variable that will be populated with an error message, if any.
	 *
	 * @return bool Returns true if the test was successful, otherwise false.
	 */
	public function test( &$error ) {
		if ( ! parent::test( $error ) ) {
			return false;
		}

		if ( 'sftp' === $this->_config['type'] ) {
			return $this->_test_sftp( $error );
		}

		$rand     = md5( time() );
		$tmp_dir  = 'test_dir_' . $rand;
		$tmp_file = 'test_file_' . $rand;
		$tmp_path = W3TC_CACHE_TMP_DIR . '/' . $tmp_file;

		if ( ! @file_put_contents( $tmp_path, $rand ) ) {
			$error = sprintf( 'Unable to create file: %s.', $tmp_path );

			return false;
		}

		if ( ! $this->_connect( $error ) ) {
			return false;
		}

		$this->_set_error_handler();

		if ( ! @ftp_mkdir( $this->_ftp, $tmp_dir ) ) {
			$error = sprintf( 'Unable to make directory: %s (%s).', $tmp_dir, $this->_get_last_error() );

			@unlink( $tmp_path );

			$this->_restore_error_handler();
			$this->_disconnect();

			return false;
		}

		if ( file_exists( $this->_config['docroot'] . '/' . $tmp_dir ) ) {
			$error = sprintf( 'Test directory was made in your site root, not on separate FTP host or path. Change path or FTP information: %s.', $tmp_dir );

			@unlink( $tmp_path );
			@ftp_rmdir( $this->_ftp, $tmp_dir );

			$this->_restore_error_handler();
			$this->_disconnect();

			return false;
		}

		if ( ! @ftp_chdir( $this->_ftp, $tmp_dir ) ) {
			$error = sprintf( 'Unable to change directory to: %s (%s).', $tmp_dir, $this->_get_last_error() );

			@unlink( $tmp_path );
			@ftp_rmdir( $this->_ftp, $tmp_dir );

			$this->_restore_error_handler();
			$this->_disconnect();

			return false;
		}

		if ( ! @ftp_put( $this->_ftp, $tmp_file, $tmp_path, FTP_BINARY ) ) {
			$error = sprintf( 'Unable to upload file: %s (%s).', $tmp_path, $this->_get_last_error() );

			@unlink( $tmp_path );
			@ftp_cdup( $this->_ftp );
			@ftp_rmdir( $this->_ftp, $tmp_dir );

			$this->_restore_error_handler();
			$this->_disconnect();

			return false;
		}

		@unlink( $tmp_path );

		if ( ! @ftp_delete( $this->_ftp, $tmp_file ) ) {
			$error = sprintf( 'Unable to delete file: %s (%s).', $tmp_path, $this->_get_last_error() );

			@ftp_cdup( $this->_ftp );
			@ftp_rmdir( $this->_ftp, $tmp_dir );

			$this->_restore_error_handler();
			$this->_disconnect();

			return false;
		}

		@ftp_cdup( $this->_ftp );

		if ( ! @ftp_rmdir( $this->_ftp, $tmp_dir ) ) {
			$error = sprintf( 'Unable to remove directory: %s (%s).', $tmp_dir, $this->_get_last_error() );

			$this->_restore_error_handler();
			$this->_disconnect();

			return false;
		}

		$this->_restore_error_handler();
		$this->_disconnect();

		return true;
	}

	/**
	 * Tests SFTP-specific functionality, including directory creation and file upload/delete.
	 *
	 * This method is specifically designed to test SFTP connections by creating directories, uploading
	 * a test file, and performing file deletions using SFTP commands. If any operation fails, an error message
	 * is returned via the $error parameter.
	 *
	 * @param string $error A reference to a variable that will be populated with an error message, if any.
	 *
	 * @return bool Returns true if the SFTP test was successful, otherwise false.
	 */
	public function _test_sftp( &$error ) {
		$rand        = md5( time() );
		$tmp_dir     = 'test_dir_' . $rand;
		$tmp_file    = 'test_file_' . $rand;
		$local_path  = W3TC_CACHE_TMP_DIR . '/' . $tmp_file;
		$remote_path = $tmp_dir . '/' . $tmp_file;

		if ( ! @file_put_contents( $local_path, $rand ) ) {
			$error = sprintf( 'Unable to create file: %s.', $local_path );

			return false;
		}

		if ( ! $this->_connect( $error ) ) {
			return false;
		}

		$sftp = @ssh2_sftp( $this->_ftp );

		$this->_set_error_handler();

		if ( ! @ssh2_sftp_mkdir( $sftp, $tmp_dir ) ) {
			$error = sprintf( 'Unable to make directory: %s (%s).', $tmp_dir, $this->_get_last_error() );

			@unlink( $local_path );

			$this->_restore_error_handler();
			$this->_disconnect();

			return false;
		}

		if ( file_exists( $this->_config['docroot'] . '/' . $tmp_dir ) ) {
			$error = sprintf( 'Test directory was made in your site root, not on separate FTP host or path. Change path or FTP information: %s.', $tmp_dir );

			@unlink( $local_path );
			@ssh2_sftp_rmdir( $sftp, $tmp_dir );

			$this->_restore_error_handler();
			$this->_disconnect();

			return false;
		}

		if ( ! @ssh2_scp_send( $this->_ftp, $local_path, $remote_path ) ) {
			$error = sprintf( 'Unable to upload file: %s (%s).', $local_path, $this->_get_last_error() );

			@unlink( $local_path );
			@ssh2_sftp_rmdir( $sftp, $tmp_dir );

			$this->_restore_error_handler();
			$this->_disconnect();

			return false;
		}

		@unlink( $local_path );

		if ( ! @ssh2_sftp_unlink( $sftp, $remote_path ) ) {
			$error = sprintf( 'Unable to delete file: %s (%s).', $local_path, $this->_get_last_error() );

			@ssh2_sftp_rmdir( $sftp, $tmp_dir );

			$this->_restore_error_handler();
			$this->_disconnect();

			return false;
		}

		if ( ! @ssh2_sftp_rmdir( $sftp, $tmp_dir ) ) {
			$error = sprintf( 'Unable to remove directory: %s (%s).', $tmp_dir, $this->_get_last_error() );

			$this->_restore_error_handler();
			$this->_disconnect();

			return false;
		}

		$this->_restore_error_handler();
		$this->_disconnect();

		return true;
	}

	/**
	 * Retrieves the domains configured for the CDN.
	 *
	 * This method returns the domains associated with the CDN configuration, or an empty array if no
	 * domains are configured.
	 *
	 * @return array An array of domain names.
	 */
	public function get_domains() {
		if ( ! empty( $this->_config['domain'] ) ) {
			return (array) $this->_config['domain'];
		}

		return array();
	}

	/**
	 * Returns the headers support level for the CDN.
	 *
	 * This method returns the type of header mirroring support available for the CDN configuration.
	 *
	 * @return string The header mirroring type supported by the CDN.
	 */
	public function headers_support() {
		return W3TC_CDN_HEADER_MIRRORING;
	}
}