<?php

/**

 * WordPress Filesystem Class for implementing SSH2

 *

 * To use this class you must follow these steps for PHP 5.2.6+

 *

 * {@link http://kevin.vanzonneveld.net/techblog/article/make_ssh_connections_with_php/ - Installation Notes}

 *

 * Compile libssh2 (Note: Only 0.14 is officially working with PHP 5.2.6+ right now, But many users have found the latest versions work)

 *

 * cd /usr/src

 * wget https://www.libssh2.org/download/libssh2-0.14.tar.gz

 * tar -zxvf libssh2-0.14.tar.gz

 * cd libssh2-0.14/

 * ./configure

 * make all install

 *

 * Note: Do not leave the directory yet!

 *

 * Enter: pecl install -f ssh2

 *

 * Copy the ssh.so file it creates to your PHP Module Directory.

 * Open up your PHP.INI file and look for where extensions are placed.

 * Add in your PHP.ini file: extension=ssh2.so

 *

 * Restart Apache!

 * Check phpinfo() streams to confirm that: ssh2.shell, ssh2.exec, ssh2.tunnel, ssh2.scp, ssh2.sftp  exist.

 *

 * Note: As of WordPress 2.8, this utilizes the PHP5+ function `stream_get_contents()`.

 *

 * @since 2.7.0

 *

 * @package WordPress

 * @subpackage Filesystem

 */

class WP_Filesystem_SSH2 extends WP_Filesystem_Base {

	/**

	 * @since 2.7.0

	 * @var resource

	 */

	public $link = false;

	/**

	 * @since 2.7.0

	 * @var resource

	 */

	public $sftp_link;

	/**

	 * @since 2.7.0

	 * @var bool

	 */

	public $keys = false;

	/**

	 * Constructor.

	 *

	 * @since 2.7.0

	 *

	 * @param array $opt

	 */

	public function __construct( $opt = '' ) {

		$this->method = 'ssh2';

		$this->errors = new WP_Error();

		// Check if possible to use ssh2 functions.

		if ( ! extension_loaded( 'ssh2' ) ) {

			$this->errors->add( 'no_ssh2_ext', __( 'The ssh2 PHP extension is not available' ) );

			return;

		}

		// Set defaults:

		if ( empty( $opt['port'] ) ) {

			$this->options['port'] = 22;

		} else {

			$this->options['port'] = $opt['port'];

		}

		if ( empty( $opt['hostname'] ) ) {

			$this->errors->add( 'empty_hostname', __( 'SSH2 hostname is required' ) );

		} else {

			$this->options['hostname'] = $opt['hostname'];

		}

		// Check if the options provided are OK.

		if ( ! empty( $opt['public_key'] ) && ! empty( $opt['private_key'] ) ) {

			$this->options['public_key']  = $opt['public_key'];

			$this->options['private_key'] = $opt['private_key'];

			$this->options['hostkey'] = array( 'hostkey' => 'ssh-rsa,ssh-ed25519' );

			$this->keys = true;

		} elseif ( empty( $opt['username'] ) ) {

			$this->errors->add( 'empty_username', __( 'SSH2 username is required' ) );

		}

		if ( ! empty( $opt['username'] ) ) {

			$this->options['username'] = $opt['username'];

		}

		if ( empty( $opt['password'] ) ) {

			// Password can be blank if we are using keys.

			if ( ! $this->keys ) {

				$this->errors->add( 'empty_password', __( 'SSH2 password is required' ) );

			} else {

				$this->options['password'] = null;

			}

		} else {

			$this->options['password'] = $opt['password'];

		}

	}

	/**

	 * Connects filesystem.

	 *

	 * @since 2.7.0

	 *

	 * @return bool True on success, false on failure.

	 */

	public function connect() {

		if ( ! $this->keys ) {

			$this->link = @ssh2_connect( $this->options['hostname'], $this->options['port'] );

		} else {

			$this->link = @ssh2_connect( $this->options['hostname'], $this->options['port'], $this->options['hostkey'] );

		}

		if ( ! $this->link ) {

			$this->errors->add(

				'connect',

				sprintf(

					/* translators: %s: hostname:port */

					__( 'Failed to connect to SSH2 Server %s' ),

					$this->options['hostname'] . ':' . $this->options['port']

				)

			);

			return false;

		}

		if ( ! $this->keys ) {

			if ( ! @ssh2_auth_password( $this->link, $this->options['username'], $this->options['password'] ) ) {

				$this->errors->add(

					'auth',

					sprintf(

						/* translators: %s: Username. */

						__( 'Username/Password incorrect for %s' ),

						$this->options['username']

					)

				);

				return false;

			}

		} else {

			if ( ! @ssh2_auth_pubkey_file( $this->link, $this->options['username'], $this->options['public_key'], $this->options['private_key'], $this->options['password'] ) ) {

				$this->errors->add(

					'auth',

					sprintf(

						/* translators: %s: Username. */

						__( 'Public and Private keys incorrect for %s' ),

						$this->options['username']

					)

				);

				return false;

			}

		}

		$this->sftp_link = ssh2_sftp( $this->link );

		if ( ! $this->sftp_link ) {

			$this->errors->add(

				'connect',

				sprintf(

					/* translators: %s: hostname:port */

					__( 'Failed to initialize a SFTP subsystem session with the SSH2 Server %s' ),

					$this->options['hostname'] . ':' . $this->options['port']

				)

			);

			return false;

		}

		return true;

	}

	/**

	 * Gets the ssh2.sftp PHP stream wrapper path to open for the given file.

	 *

	 * This method also works around a PHP bug where the root directory (/) cannot

	 * be opened by PHP functions, causing a false failure. In order to work around

	 * this, the path is converted to /./ which is semantically the same as /

	 * See https://bugs.php.net/bug.php?id=64169 for more details.

	 *

	 * @since 4.4.0

	 *

	 * @param string $path The File/Directory path on the remote server to return

	 * @return string The ssh2.sftp:// wrapped path to use.

	 */

	public function sftp_path( $path ) {

		if ( '/' === $path ) {

			$path = '/./';

		}

		return 'ssh2.sftp://' . $this->sftp_link . '/' . ltrim( $path, '/' );

	}

	/**

	 * @since 2.7.0

	 *

	 * @param string $command

	 * @param bool   $returnbool

	 * @return bool|string True on success, false on failure. String if the command was executed, `$returnbool`

	 *                     is false (default), and data from the resulting stream was retrieved.

	 */

	public function run_command( $command, $returnbool = false ) {

		if ( ! $this->link ) {

			return false;

		}

		$stream = ssh2_exec( $this->link, $command );

		if ( ! $stream ) {

			$this->errors->add(

				'command',

				sprintf(

					/* translators: %s: Command. */

					__( 'Unable to perform command: %s' ),

					$command

				)

			);

		} else {

			stream_set_blocking( $stream, true );

			stream_set_timeout( $stream, FS_TIMEOUT );

			$data = stream_get_contents( $stream );

			fclose( $stream );

			if ( $returnbool ) {

				return ( false === $data ) ? false : '' !== trim( $data );

			} else {

				return $data;

			}

		}

		return false;

	}

	/**

	 * Reads entire file into a string.

	 *

	 * @since 2.7.0

	 *

	 * @param string $file Name of the file to read.

	 * @return string|false Read data on success, false if no temporary file could be opened,

	 *                      or if the file couldn't be retrieved.

	 */

	public function get_contents( $file ) {

		return file_get_contents( $this->sftp_path( $file ) );

	}

	/**

	 * Reads entire file into an array.

	 *

	 * @since 2.7.0

	 *

	 * @param string $file Path to the file.

	 * @return array|false File contents in an array on success, false on failure.

	 */

	public function get_contents_array( $file ) {

		return file( $this->sftp_path( $file ) );

	}

	/**

	 * Writes a string to a file.

	 *

	 * @since 2.7.0

	 *

	 * @param string    $file     Remote path to the file where to write the data.

	 * @param string    $contents The data to write.

	 * @param int|false $mode     Optional. The file permissions as octal number, usually 0644.

	 *                            Default false.

	 * @return bool True on success, false on failure.

	 */

	public function put_contents( $file, $contents, $mode = false ) {

		$ret = file_put_contents( $this->sftp_path( $file ), $contents );

		if ( strlen( $contents ) !== $ret ) {

			return false;

		}

		$this->chmod( $file, $mode );

		return true;

	}

	/**

	 * Gets the current working directory.

	 *

	 * @since 2.7.0

	 *

	 * @return string|false The current working directory on success, false on failure.

	 */

	public function cwd() {

		$cwd = ssh2_sftp_realpath( $this->sftp_link, '.' );

		if ( $cwd ) {

			$cwd = trailingslashit( trim( $cwd ) );

		}

		return $cwd;

	}

	/**

	 * Changes current directory.

	 *

	 * @since 2.7.0

	 *

	 * @param string $dir The new current directory.

	 * @return bool True on success, false on failure.

	 */

	public function chdir( $dir ) {

		return $this->run_command( 'cd ' . $dir, true );

	}

	/**

	 * Changes the file group.

	 *

	 * @since 2.7.0

	 *

	 * @param string     $file      Path to the file.

	 * @param string|int $group     A group name or number.

	 * @param bool       $recursive Optional. If set to true, changes file group recursively.

	 *                              Default false.

	 * @return bool True on success, false on failure.

	 */

	public function chgrp( $file, $group, $recursive = false ) {

		if ( ! $this->exists( $file ) ) {

			return false;

		}

		if ( ! $recursive || ! $this->is_dir( $file ) ) {

			return $this->run_command( sprintf( 'chgrp %s %s', escapeshellarg( $group ), escapeshellarg( $file ) ), true );

		}

		return $this->run_command( sprintf( 'chgrp -R %s %s', escapeshellarg( $group ), escapeshellarg( $file ) ), true );

	}

	/**

	 * Changes filesystem permissions.

	 *

	 * @since 2.7.0

	 *

	 * @param string    $file      Path to the file.

	 * @param int|false $mode      Optional. The permissions as octal number, usually 0644 for files,

	 *                             0755 for directories. Default false.

	 * @param bool      $recursive Optional. If set to true, changes file permissions recursively.

	 *                             Default false.

	 * @return bool True on success, false on failure.

	 */

	public function chmod( $file, $mode = false, $recursive = false ) {

		if ( ! $this->exists( $file ) ) {

			return false;

		}

		if ( ! $mode ) {

			if ( $this->is_file( $file ) ) {

				$mode = FS_CHMOD_FILE;

			} elseif ( $this->is_dir( $file ) ) {

				$mode = FS_CHMOD_DIR;

			} else {

				return false;

			}

		}

		if ( ! $recursive || ! $this->is_dir( $file ) ) {

			return $this->run_command( sprintf( 'chmod %o %s', $mode, escapeshellarg( $file ) ), true );

		}

		return $this->run_command( sprintf( 'chmod -R %o %s', $mode, escapeshellarg( $file ) ), true );

	}

	/**

	 * Changes the owner of a file or directory.

	 *

	 * @since 2.7.0

	 *

	 * @param string     $file      Path to the file or directory.

	 * @param string|int $owner     A user name or number.

	 * @param bool       $recursive Optional. If set to true, changes file owner recursively.

	 *                              Default false.

	 * @return bool True on success, false on failure.

	 */

	public function chown( $file, $owner, $recursive = false ) {

		if ( ! $this->exists( $file ) ) {

			return false;

		}

		if ( ! $recursive || ! $this->is_dir( $file ) ) {

			return $this->run_command( sprintf( 'chown %s %s', escapeshellarg( $owner ), escapeshellarg( $file ) ), true );

		}

		return $this->run_command( sprintf( 'chown -R %s %s', escapeshellarg( $owner ), escapeshellarg( $file ) ), true );

	}

	/**