Email.php

<?php
/**
 * CodeIgniter
 *
 * An open source application development framework for PHP
 *
 * This content is released under the MIT License (MIT)
 *
 * Copyright (c) 2019 - 2022, CodeIgniter Foundation
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 *
 * @package	CodeIgniter
 * @author	EllisLab Dev Team
 * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
 * @copyright	Copyright (c) 2014 - 2019, British Columbia Institute of Technology (https://bcit.ca/)
 * @copyright	Copyright (c) 2019 - 2022, CodeIgniter Foundation (https://codeigniter.com/)
 * @license	https://opensource.org/licenses/MIT	MIT License
 * @link	https://codeigniter.com
 * @since	Version 1.0.0
 * @filesource
 */
defined('BASEPATH') OR exit('No direct script access allowed');

/**
 * CodeIgniter Email Class
 *
 * Permits email to be sent using Mail, Sendmail, or SMTP.
 *
 * @package		CodeIgniter
 * @subpackage	Libraries
 * @category	Libraries
 * @author		EllisLab Dev Team
 * @link		https://codeigniter.com/userguide3/libraries/email.html
 */
class CI_Email {

	/**
	 * Used as the User-Agent and X-Mailer headers' value.
	 *
	 * @var	string
	 */
	public $useragent	= 'CodeIgniter';

	/**
	 * Path to the Sendmail binary.
	 *
	 * @var	string
	 */
	public $mailpath	= '/usr/sbin/sendmail';	// Sendmail path

	/**
	 * Which method to use for sending e-mails.
	 *
	 * @var	string	'mail', 'sendmail' or 'smtp'
	 */
	public $protocol	= 'mail';		// mail/sendmail/smtp

	/**
	 * STMP Server host
	 *
	 * @var	string
	 */
	public $smtp_host	= '';

	/**
	 * SMTP Username
	 *
	 * @var	string
	 */
	public $smtp_user	= '';

	/**
	 * SMTP Password
	 *
	 * @var	string
	 */
	public $smtp_pass	= '';

	/**
	 * SMTP Server port
	 *
	 * @var	int
	 */
	public $smtp_port	= 25;

	/**
	 * SMTP connection timeout in seconds
	 *
	 * @var	int
	 */
	public $smtp_timeout	= 5;

	/**
	 * SMTP persistent connection
	 *
	 * @var	bool
	 */
	public $smtp_keepalive	= FALSE;

	/**
	 * SMTP Encryption
	 *
	 * @var	string	empty, 'tls' or 'ssl'
	 */
	public $smtp_crypto	= '';

	/**
	 * Whether to apply word-wrapping to the message body.
	 *
	 * @var	bool
	 */
	public $wordwrap	= TRUE;

	/**
	 * Number of characters to wrap at.
	 *
	 * @see	CI_Email::$wordwrap
	 * @var	int
	 */
	public $wrapchars	= 76;

	/**
	 * Message format.
	 *
	 * @var	string	'text' or 'html'
	 */
	public $mailtype	= 'text';

	/**
	 * Character set (default: utf-8)
	 *
	 * @var	string
	 */
	public $charset		= 'utf-8';

	/**
	 * Alternative message (for HTML messages only)
	 *
	 * @var	string
	 */
	public $alt_message	= '';

	/**
	 * Whether to validate e-mail addresses.
	 *
	 * @var	bool
	 */
	public $validate	= TRUE;

	/**
	 * X-Priority header value.
	 *
	 * @var	int	1-5
	 */
	public $priority	= 3;			// Default priority (1 - 5)

	/**
	 * Newline character sequence.
	 * Use "\r\n" to comply with RFC 822.
	 *
	 * @link	https://www.ietf.org/rfc/rfc822.txt
	 * @var	string	"\r\n" or "\n"
	 */
	public $newline		= "\n";			// Default newline. "\r\n" or "\n" (Use "\r\n" to comply with RFC 822)

	/**
	 * CRLF character sequence
	 *
	 * RFC 2045 specifies that for 'quoted-printable' encoding,
	 * "\r\n" must be used. However, it appears that some servers
	 * (even on the receiving end) don't handle it properly and
	 * switching to "\n", while improper, is the only solution
	 * that seems to work for all environments.
	 *
	 * @link	https://www.ietf.org/rfc/rfc822.txt
	 * @var	string
	 */
	public $crlf		= "\n";

	/**
	 * Whether to use Delivery Status Notification.
	 *
	 * @var	bool
	 */
	public $dsn		= FALSE;

	/**
	 * Whether to send multipart alternatives.
	 * Yahoo! doesn't seem to like these.
	 *
	 * @var	bool
	 */
	public $send_multipart	= TRUE;

	/**
	 * Whether to send messages to BCC recipients in batches.
	 *
	 * @var	bool
	 */
	public $bcc_batch_mode	= FALSE;

	/**
	 * BCC Batch max number size.
	 *
	 * @see	CI_Email::$bcc_batch_mode
	 * @var	int
	 */
	public $bcc_batch_size	= 200;

	// --------------------------------------------------------------------

	/**
	 * Subject header
	 *
	 * @var	string
	 */
	protected $_subject		= '';

	/**
	 * Message body
	 *
	 * @var	string
	 */
	protected $_body		= '';

	/**
	 * Final message body to be sent.
	 *
	 * @var	string
	 */
	protected $_finalbody		= '';

	/**
	 * Final headers to send
	 *
	 * @var	string
	 */
	protected $_header_str		= '';

	/**
	 * SMTP Connection socket placeholder
	 *
	 * @var	resource
	 */
	protected $_smtp_connect	= '';

	/**
	 * Mail encoding
	 *
	 * @var	string	'8bit' or '7bit'
	 */
	protected $_encoding		= '8bit';

	/**
	 * Whether to perform SMTP authentication
	 *
	 * @var	bool
	 */
	protected $_smtp_auth		= FALSE;

	/**
	 * Whether to send a Reply-To header
	 *
	 * @var	bool
	 */
	protected $_replyto_flag	= FALSE;

	/**
	 * Debug messages
	 *
	 * @see	CI_Email::print_debugger()
	 * @var	string
	 */
	protected $_debug_msg		= array();

	/**
	 * Recipients
	 *
	 * @var	string[]
	 */
	protected $_recipients		= array();

	/**
	 * CC Recipients
	 *
	 * @var	string[]
	 */
	protected $_cc_array		= array();

	/**
	 * BCC Recipients
	 *
	 * @var	string[]
	 */
	protected $_bcc_array		= array();

	/**
	 * Message headers
	 *
	 * @var	string[]
	 */
	protected $_headers		= array();

	/**
	 * Attachment data
	 *
	 * @var	array
	 */
	protected $_attachments		= array();

	/**
	 * Valid $protocol values
	 *
	 * @see	CI_Email::$protocol
	 * @var	string[]
	 */
	protected $_protocols		= array('mail', 'sendmail', 'smtp');

	/**
	 * Base charsets
	 *
	 * Character sets valid for 7-bit encoding,
	 * excluding language suffix.
	 *
	 * @var	string[]
	 */
	protected $_base_charsets	= array('us-ascii', 'iso-2022-');

	/**
	 * Bit depths
	 *
	 * Valid mail encodings
	 *
	 * @see	CI_Email::$_encoding
	 * @var	string[]
	 */
	protected $_bit_depths		= array('7bit', '8bit');

	/**
	 * $priority translations
	 *
	 * Actual values to send with the X-Priority header
	 *
	 * @var	string[]
	 */
	protected $_priorities = array(
		1 => '1 (Highest)',
		2 => '2 (High)',
		3 => '3 (Normal)',
		4 => '4 (Low)',
		5 => '5 (Lowest)'
	);

	/**
	 * mbstring.func_overload flag
	 *
	 * @var	bool
	 */
	protected static $func_overload;

	// --------------------------------------------------------------------

	/**
	 * Constructor - Sets Email Preferences
	 *
	 * The constructor can be passed an array of config values
	 *
	 * @param	array	$config = array()
	 * @return	void
	 */
	public function __construct(array $config = array())
	{
		$this->charset = config_item('charset');
		$this->initialize($config);

		isset(self::$func_overload) OR self::$func_overload = ( ! is_php('8.0') && extension_loaded('mbstring') && @ini_get('mbstring.func_overload'));

		log_message('info', 'Email Class Initialized');
	}

	// --------------------------------------------------------------------

	/**
	 * Initialize preferences
	 *
	 * @param	array	$config
	 * @return	CI_Email
	 */
	public function initialize(array $config = array())
	{
		$this->clear();

		foreach ($config as $key => $val)
		{
			if (isset($this->$key))
			{
				$method = 'set_'.$key;

				if (method_exists($this, $method))
				{
					$this->$method($val);
				}
				else
				{
					$this->$key = $val;
				}
			}
		}

		$this->charset = strtoupper($this->charset);
		$this->_smtp_auth = isset($this->smtp_user[0], $this->smtp_pass[0]);

		return $this;
	}

	// --------------------------------------------------------------------

	/**
	 * Initialize the Email Data
	 *
	 * @param	bool
	 * @return	CI_Email
	 */
	public function clear($clear_attachments = FALSE)
	{
		$this->_subject		= '';
		$this->_body		= '';
		$this->_finalbody	= '';
		$this->_header_str	= '';
		$this->_replyto_flag	= FALSE;
		$this->_recipients	= array();
		$this->_cc_array	= array();
		$this->_bcc_array	= array();
		$this->_headers		= array();
		$this->_debug_msg	= array();

		$this->set_header('Date', $this->_set_date());

		if ($clear_attachments !== FALSE)
		{
			$this->_attachments = array();
		}

		return $this;
	}

	// --------------------------------------------------------------------

	/**
	 * Set FROM
	 *
	 * @param	string	$from
	 * @param	string	$name
	 * @param	string	$return_path = NULL	Return-Path
	 * @return	CI_Email
	 */
	public function from($from, $name = '', $return_path = NULL)
	{
		if (preg_match('/\<(.*)\>/', $from, $match))
		{
			$from = $match[1];
		}

		if ($this->validate)
		{
			$this->validate_email($this->_str_to_array($from));
			if ($return_path)
			{
				$this->validate_email($this->_str_to_array($return_path));
			}
		}

		// prepare the display name
		if ($name !== '')
		{
			// only use Q encoding if there are characters that would require it
			if ( ! preg_match('/[\200-\377]/', $name))
			{
				// add slashes for non-printing characters, slashes, and double quotes, and surround it in double quotes
				$name = '"'.addcslashes($name, "\0..\37\177'\"\\").'"';
			}
			else
			{
				$name = $this->_prep_q_encoding($name);
			}
		}

		$this->set_header('From', $name.' <'.$from.'>');

		isset($return_path) OR $return_path = $from;
		$this->set_header('Return-Path', '<'.$return_path.'>');

		return $this;
	}

	// --------------------------------------------------------------------

	/**
	 * Set Reply-to
	 *
	 * @param	string
	 * @param	string
	 * @return	CI_Email
	 */
	public function reply_to($replyto, $name = '')
	{
		if (preg_match('/\<(.*)\>/', $replyto, $match))
		{
			$replyto = $match[1];
		}

		if ($this->validate)
		{
			$this->validate_email($this->_str_to_array($replyto));
		}

		if ($name !== '')
		{
			// only use Q encoding if there are characters that would require it
			if ( ! preg_match('/[\200-\377]/', $name))
			{
				// add slashes for non-printing characters, slashes, and double quotes, and surround it in double quotes
				$name = '"'.addcslashes($name, "\0..\37\177'\"\\").'"';
			}
			else
			{
				$name = $this->_prep_q_encoding($name);
			}
		}

		$this->set_header('Reply-To', $name.' <'.$replyto.'>');
		$this->_replyto_flag = TRUE;

		return $this;
	}

	// --------------------------------------------------------------------

	/**
	 * Set Recipients
	 *
	 * @param	string
	 * @return	CI_Email
	 */
	public function to($to)
	{
		$to = $this->_str_to_array($to);
		$to = $this->clean_email($to);

		if ($this->validate)
		{
			$this->validate_email($to);
		}

		if ($this->_get_protocol() !== 'mail')
		{
			$this->set_header('To', implode(', ', $to));
		}

		$this->_recipients = $to;

		return $this;
	}

	// --------------------------------------------------------------------

	/**
	 * Set CC
	 *
	 * @param	string
	 * @return	CI_Email
	 */
	public function cc($cc)
	{
		$cc = $this->clean_email($this->_str_to_array($cc));

		if ($this->validate)
		{
			$this->validate_email($cc);
		}

		$this->set_header('Cc', implode(', ', $cc));

		if ($this->_get_protocol() === 'smtp')
		{
			$this->_cc_array = $cc;
		}

		return $this;
	}

	// --------------------------------------------------------------------

	/**
	 * Set BCC
	 *
	 * @param	string
	 * @param	string
	 * @return	CI_Email
	 */
	public function bcc($bcc, $limit = '')
	{
		if ($limit !== '' && is_numeric($limit))
		{
			$this->bcc_batch_mode = TRUE;
			$this->bcc_batch_size = $limit;
		}

		$bcc = $this->clean_email($this->_str_to_array($bcc));

		if ($this->validate)
		{
			$this->validate_email($bcc);
		}

		if ($this->_get_protocol() === 'smtp' OR ($this->bcc_batch_mode && count($bcc) > $this->bcc_batch_size))
		{
			$this->_bcc_array = $bcc;
		}
		else
		{
			$this->set_header('Bcc', implode(', ', $bcc));
		}

		return $this;
	}

	// --------------------------------------------------------------------

	/**
	 * Set Email Subject
	 *
	 * @param	string
	 * @return	CI_Email
	 */
	public function subject($subject)
	{
		$subject = $this->_prep_q_encoding($subject);
		$this->set_header('Subject', $subject);
		return $this;
	}

	// --------------------------------------------------------------------

	/**
	 * Set Body
	 *
	 * @param	string
	 * @return	CI_Email
	 */
	public function message($body)
	{
		$this->_body = rtrim(str_replace("\r", '', $body));
		return $this;
	}

	// --------------------------------------------------------------------

	/**
	 * Assign file attachments
	 *
	 * @param	string	$file	Can be local path, URL or buffered content
	 * @param	string	$disposition = 'attachment'
	 * @param	string	$newname = NULL
	 * @param	string	$mime = ''
	 * @return	CI_Email
	 */
	public function attach($file, $disposition = '', $newname = NULL, $mime = '')
	{
		if ($mime === '')
		{
			if (strpos($file, '://') === FALSE && ! file_exists($file))
			{
				$this->_set_error_message('lang:email_attachment_missing', $file);
				return FALSE;
			}

			if ( ! $fp = @fopen($file, 'rb'))
			{
				$this->_set_error_message('lang:email_attachment_unreadable', $file);
				return FALSE;
			}

			$file_content = stream_get_contents($fp);
			$mime = $this->_mime_types(pathinfo($file, PATHINFO_EXTENSION));
			fclose($fp);
		}
		else
		{
			$file_content =& $file; // buffered file
		}

		$this->_attachments[] = array(
			'name'		=> array($file, $newname),
			'disposition'	=> empty($disposition) ? 'attachment' : $disposition,  // Can also be 'inline'  Not sure if it matters
			'type'		=> $mime,
			'content'	=> chunk_split(base64_encode($file_content)),
			'multipart'	=> 'mixed'
		);

		return $this;
	}

	// --------------------------------------------------------------------

	/**
	 * Set and return attachment Content-ID
	 *
	 * Useful for attached inline pictures
	 *
	 * @param	string	$filename
	 * @return	string
	 */
	public function attachment_cid($filename)
	{
		for ($i = 0, $c = count($this->_attachments); $i < $c; $i++)
		{
			if ($this->_attachments[$i]['name'][0] === $filename)
			{
				$this->_attachments[$i]['multipart'] = 'related';
				$this->_attachments[$i]['cid'] = uniqid(basename($this->_attachments[$i]['name'][0]).'@');
				return $this->_attachments[$i]['cid'];
			}
		}

		return FALSE;
	}

	// --------------------------------------------------------------------

	/**
	 * Add a Header Item
	 *
	 * @param	string
	 * @param	string
	 * @return	CI_Email
	 */
	public function set_header($header, $value)
	{
		$this->_headers[$header] = str_replace(array("\n", "\r"), '', $value);
		return $this;
	}

	// --------------------------------------------------------------------

	/**
	 * Convert a String to an Array
	 *
	 * @param	string
	 * @return	array
	 */
	protected function _str_to_array($email)
	{
		if ( ! is_array($email))
		{
			return (strpos($email, ',') !== FALSE)
				? preg_split('/[\s,]/', $email, -1, PREG_SPLIT_NO_EMPTY)
				: (array) trim($email);
		}

		return $email;
	}

	// --------------------------------------------------------------------

	/**
	 * Set Multipart Value
	 *
	 * @param	string
	 * @return	CI_Email
	 */
	public function set_alt_message($str)
	{
		$this->alt_message = (string) $str;
		return $this;
	}

	// --------------------------------------------------------------------

	/**
	 * Set Mailtype
	 *
	 * @param	string
	 * @return	CI_Email
	 */
	public function set_mailtype($type = 'text')
	{
		$this->mailtype = ($type === 'html') ? 'html' : 'text';
		return $this;
	}

	// --------------------------------------------------------------------

	/**
	 * Set Wordwrap
	 *
	 * @param	bool
	 * @return	CI_Email
	 */
	public function set_wordwrap($wordwrap = TRUE)
	{
		$this->wordwrap = (bool) $wordwrap;
		return $this;
	}

	// --------------------------------------------------------------------

	/**
	 * Set Protocol
	 *
	 * @param	string
	 * @return	CI_Email
	 */
	public function set_protocol($protocol = 'mail')
	{
		$this->protocol = in_array($protocol, $this->_protocols, TRUE) ? strtolower($protocol) : 'mail';
		return $this;
	}

	// --------------------------------------------------------------------

	/**
	 * Set Priority
	 *
	 * @param	int
	 * @return	CI_Email
	 */
	public function set_priority($n = 3)
	{
		$this->priority = preg_match('/^[1-5]$/', $n) ? (int) $n : 3;
		return $this;
	}

	// --------------------------------------------------------------------

	/**
	 * Set Newline Character
	 *
	 * @param	string
	 * @return	CI_Email
	 */
	public function set_newline($newline = "\n")
	{
		$this->newline = in_array($newline, array("\n", "\r\n", "\r")) ? $newline : "\n";
		return $this;
	}

	// --------------------------------------------------------------------

	/**
	 * Set CRLF
	 *
	 * @param	string
	 * @return	CI_Email
	 */
	public function set_crlf($crlf = "\n")
	{
		$this->crlf = ($crlf !== "\n" && $crlf !== "\r\n" && $crlf !== "\r") ? "\n" : $crlf;
		return $this;
	}

	// --------------------------------------------------------------------

	/**
	 * Get the Message ID
	 *
	 * @return	string
	 */
	protected function _get_message_id()
	{
		$from = str_replace(array('>', '<'), '', $this->_headers['Return-Path']);
		return '<'.uniqid('').strstr($from, '@').'>';
	}

	// --------------------------------------------------------------------

	/**
	 * Get Mail Protocol
	 *
	 * @return	mixed
	 */
	protected function _get_protocol()
	{
		$this->protocol = strtolower($this->protocol);
		in_array($this->protocol, $this->_protocols, TRUE) OR $this->protocol = 'mail';
		return $this->protocol;
	}

	// --------------------------------------------------------------------

	/**
	 * Get Mail Encoding
	 *
	 * @return	string
	 */
	protected function _get_encoding()
	{
		in_array($this->_encoding, $this->_bit_depths) OR $this->_encoding = '8bit';

		foreach ($this->_base_charsets as $charset)
		{
			if (strpos($this->charset, $charset) === 0)
			{
				$this->_encoding = '7bit';
			}
		}

		return $this->_encoding;
	}

	// --------------------------------------------------------------------

	/**
	 * Get content type (text/html/attachment)
	 *
	 * @return	string
	 */
	protected function _get_content_type()
	{
		if ($this->mailtype === 'html')
		{
			return empty($this->_attachments) ? 'html' : 'html-attach';
		}
		elseif	($this->mailtype === 'text' && ! empty($this->_attachments))
		{
			return 'plain-attach';
		}

		return 'plain';
	}

	// --------------------------------------------------------------------

	/**
	 * Set RFC 822 Date
	 *
	 * @return	string
	 */
	protected function _set_date()
	{
		$timezone = date('Z');
		$operator = ($timezone[0] === '-') ? '-' : '+';
		$timezone = abs($timezone);
		$timezone = floor($timezone/3600) * 100 + ($timezone % 3600) / 60;

		return sprintf('%s %s%04d', date('D, j M Y H:i:s'), $operator, $timezone);
	}

	// --------------------------------------------------------------------

	/**
	 * Mime message
	 *
	 * @return	string
	 */
	protected function _get_mime_message()
	{
		return 'This is a multi-part message in MIME format.'.$this->newline.'Your email application may not support this format.';
	}

	// --------------------------------------------------------------------

	/**
	 * Validate Email Address
	 *
	 * @param	string
	 * @return	bool
	 */
	public function validate_email($email)
	{
		if ( ! is_array($email))
		{
			$this->_set_error_message('lang:email_must_be_array');
			return FALSE;
		}

		foreach ($email as $val)
		{
			if ( ! $this->valid_email($val))
			{
				$this->_set_error_message('lang:email_invalid_address', $val);
				return FALSE;
			}