Basic class to connect to an FTP server with Implicit SSL/TLS and upload a file

class-ftp-implicit-ssl-tls.php

<?php
/**
 * FTP with Implicit SSL/TLS Class
 *
 * Simple wrapper for cURL functions to transfer an ASCII file over FTP with implicit SSL/TLS
 *
 * @category    Class
 * @author      Max Rice
 * @since       1.0
 */

class FTP_Implicit_SSL {

	/** @var resource cURL resource handle */
	private $curl_handle;

	/** @var string cURL URL for upload */
	private $url;

	/**
	 * Connect to FTP server over Implicit SSL/TLS
	 *
	 *
	 * @access public
	 * @since 1.0
	 * @param string $username
	 * @param string $password
	 * @param string $server
	 * @param int $port
	 * @param string $initial_path
	 * @param bool $passive_mode
	 * @throws Exception - blank username / password / port
	 * @return \FTP_Implicit_SSL
	 */
	public function __construct( $username, $password, $server, $port = 990, $initial_path = '', $passive_mode = false ) {

		// check for blank username
		if ( ! $username )
			throw new Exception( 'FTP Username is blank.' );

		// don't check for blank password (highly-questionable use case, but still)

		// check for blank server
		if ( ! $server )
			throw new Exception( 'FTP Server is blank.' );

		// check for blank port
		if ( ! $port )
			throw new Exception ( 'FTP Port is blank.');

		// set host/initial path
		$this->url = "ftps://{$server}/{$initial_path}";

		// setup connection
		$this->curl_handle = curl_init();

		// check for successful connection
		if ( ! $this->curl_handle )
			throw new Exception( 'Could not initialize cURL.' );

		// connection options
		$options = array(
			CURLOPT_USERPWD        => $username . ':' . $password,
			CURLOPT_SSL_VERIFYPEER => false, // don't verify SSL
			CURLOPT_SSL_VERIFYHOST => false,
			CURLOPT_FTP_SSL        => CURLFTPSSL_ALL, // require SSL For both control and data connections
			CURLOPT_FTPSSLAUTH     => CURLFTPAUTH_DEFAULT, // let cURL choose the FTP authentication method (either SSL or TLS)
			CURLOPT_UPLOAD         => true,
			CURLOPT_PORT           => $port,
			CURLOPT_TIMEOUT        => 30,
		);

		// cURL FTP enables passive mode by default, so disable it by enabling the PORT command and allowing cURL to select the IP address for the data connection
		if ( ! $passive_mode )
			$options[ CURLOPT_FTPPORT ] = '-';

		// set connection options, use foreach so useful errors can be caught instead of a generic "cannot set options" error with curl_setopt_array()
		foreach ( $options as $option_name => $option_value ) {

			if ( ! curl_setopt( $this->curl_handle, $option_name, $option_value ) )
				throw new Exception( sprintf( 'Could not set cURL option: %s', $option_name ) );
		}

	}

	/**
	 * Write file into temporary memory and upload stream to remote file
	 *
	 * @access public
	 * @since 1.0
	 * @param string $file_name - remote file name to create
	 * @param string $file - file content to upload
	 * @throws Exception - Open remote file failure or write data failure
	 */
	public function upload( $file_name, $file ) {

		// set file name
		if ( ! curl_setopt( $this->curl_handle, CURLOPT_URL, $this->url . $file_name ))
			throw new Exception ( "Could not set cURL file name: $file_name" );

		// open memory stream for writing
		$stream = fopen( 'php://temp', 'w+' );

		// check for valid stream handle
		if ( ! $stream )
			throw new Exception( 'Could not open php://temp for writing.' );

		// write file into the temporary stream
		fwrite( $stream, $file );

		// rewind the stream pointer
		rewind( $stream );

		// set the file to be uploaded
		if ( ! curl_setopt( $this->curl_handle, CURLOPT_INFILE, $stream ) )
			throw new Exception( "Could not load file $file_name" );

		// upload file
		if ( ! curl_exec( $this->curl_handle ) )
			throw new Exception( sprintf( 'Could not upload file. cURL Error: [%s] - %s', curl_errno( $this->curl_handle ), curl_error( $this->curl_handle ) ) );

		// close the stream handle
		fclose( $stream );
	}

	/**
	 * Attempt to close cURL handle
	 * Note - errors suppressed here as they are not useful
	 *
	 * @access public
	 * @since 1.0
	 */
	public function __destruct() {

		@curl_close( $this->curl_handle );
	}

}