Merge "Update docs/hooks.txt for ShowSearchHitTitle"

[mediawiki.git] / includes / mail / UserMailer.php

<?php
/**
 * Classes used to send e-mails
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program; if not, write to the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 * http://www.gnu.org/copyleft/gpl.html
 *
 * @file
 * @author <brion@pobox.com>
 * @author <mail@tgries.de>
 * @author Tim Starling
 * @author Luke Welling lwelling@wikimedia.org
 */

/**
 * Collection of static functions for sending mail
 */
class UserMailer {
        private static $mErrorString;

        /**
         * Send mail using a PEAR mailer
         *
         * @param Mail_smtp $mailer
         * @param string $dest
         * @param string $headers
         * @param string $body
         *
         * @return Status
         */
        protected static function sendWithPear( $mailer, $dest, $headers, $body ) {
                $mailResult = $mailer->send( $dest, $headers, $body );

                // Based on the result return an error string,
                if ( PEAR::isError( $mailResult ) ) {
                        wfDebug( "PEAR::Mail failed: " . $mailResult->getMessage() . "\n" );
                        return Status::newFatal( 'pear-mail-error', $mailResult->getMessage() );
                } else {
                        return Status::newGood();
                }
        }

        /**
         * Creates a single string from an associative array
         *
         * @param array $headers Associative Array: keys are header field names,
         *                 values are ... values.
         * @param string $endl The end of line character.  Defaults to "\n"
         *
         * Note RFC2822 says newlines must be CRLF (\r\n)
         * but php mail naively "corrects" it and requires \n for the "correction" to work
         *
         * @return string
         */
        static function arrayToHeaderString( $headers, $endl = PHP_EOL ) {
                $strings = [];
                foreach ( $headers as $name => $value ) {
                        // Prevent header injection by stripping newlines from value
                        $value = self::sanitizeHeaderValue( $value );
                        $strings[] = "$name: $value";
                }
                return implode( $endl, $strings );
        }

        /**
         * Create a value suitable for the MessageId Header
         *
         * @return string
         */
        static function makeMsgId() {
                global $wgSMTP, $wgServer;

                $msgid = uniqid( wfWikiID() . ".", true ); /* true required for cygwin */
                if ( is_array( $wgSMTP ) && isset( $wgSMTP['IDHost'] ) && $wgSMTP['IDHost'] ) {
                        $domain = $wgSMTP['IDHost'];
                } else {
                        $url = wfParseUrl( $wgServer );
                        $domain = $url['host'];
                }
                return "<$msgid@$domain>";
        }

        /**
         * This function will perform a direct (authenticated) login to
         * a SMTP Server to use for mail relaying if 'wgSMTP' specifies an
         * array of parameters. It requires PEAR:Mail to do that.
         * Otherwise it just uses the standard PHP 'mail' function.
         *
         * @param MailAddress|MailAddress[] $to Recipient's email (or an array of them)
         * @param MailAddress $from Sender's email
         * @param string $subject Email's subject.
         * @param string $body Email's text or Array of two strings to be the text and html bodies
         * @param array $options:
         *              'replyTo' MailAddress
         *              'contentType' string default 'text/plain; charset=UTF-8'
         *              'headers' array Extra headers to set
         *
         * @throws MWException
         * @throws Exception
         * @return Status
         */
        public static function send( $to, $from, $subject, $body, $options = [] ) {
                global $wgAllowHTMLEmail;

                if ( !isset( $options['contentType'] ) ) {
                        $options['contentType'] = 'text/plain; charset=UTF-8';
                }

                if ( !is_array( $to ) ) {
                        $to = [ $to ];
                }

                // mail body must have some content
                $minBodyLen = 10;
                // arbitrary but longer than Array or Object to detect casting error

                // body must either be a string or an array with text and body
                if (
                        !(
                                !is_array( $body ) &&
                                strlen( $body ) >= $minBodyLen
                        )
                        &&
                        !(
                                is_array( $body ) &&
                                isset( $body['text'] ) &&
                                isset( $body['html'] ) &&
                                strlen( $body['text'] ) >= $minBodyLen &&
                                strlen( $body['html'] ) >= $minBodyLen
                        )
                ) {
                        // if it is neither we have a problem
                        return Status::newFatal( 'user-mail-no-body' );
                }

                if ( !$wgAllowHTMLEmail && is_array( $body ) ) {
                        // HTML not wanted.  Dump it.
                        $body = $body['text'];
                }

                wfDebug( __METHOD__ . ': sending mail to ' . implode( ', ', $to ) . "\n" );

                // Make sure we have at least one address
                $has_address = false;
                foreach ( $to as $u ) {
                        if ( $u->address ) {
                                $has_address = true;
                                break;
                        }
                }
                if ( !$has_address ) {
                        return Status::newFatal( 'user-mail-no-addy' );
                }

                // give a chance to UserMailerTransformContents subscribers who need to deal with each
                // target differently to split up the address list
                if ( count( $to ) > 1 ) {
                        $oldTo = $to;
                        Hooks::run( 'UserMailerSplitTo', [ &$to ] );
                        if ( $oldTo != $to ) {
                                $splitTo = array_diff( $oldTo, $to );
                                $to = array_diff( $oldTo, $splitTo ); // ignore new addresses added in the hook
                                // first send to non-split address list, then to split addresses one by one
                                $status = Status::newGood();
                                if ( $to ) {
                                        $status->merge( UserMailer::sendInternal(
                                                $to, $from, $subject, $body, $options ) );
                                }
                                foreach ( $splitTo as $newTo ) {
                                        $status->merge( UserMailer::sendInternal(
                                                [ $newTo ], $from, $subject, $body, $options ) );
                                }
                                return $status;
                        }
                }

                return UserMailer::sendInternal( $to, $from, $subject, $body, $options );
        }

        /**
         * Helper function fo UserMailer::send() which does the actual sending. It expects a $to
         * list which the UserMailerSplitTo hook would not split further.
         * @param MailAddress[] $to Array of recipients' email addresses
         * @param MailAddress $from Sender's email
         * @param string $subject Email's subject.
         * @param string $body Email's text or Array of two strings to be the text and html bodies
         * @param array $options:
         *              'replyTo' MailAddress
         *              'contentType' string default 'text/plain; charset=UTF-8'
         *              'headers' array Extra headers to set
         *
         * @throws MWException
         * @throws Exception
         * @return Status
         */
        protected static function sendInternal(
                array $to,
                MailAddress $from,
                $subject,
                $body,
                $options = []
        ) {
                global $wgSMTP, $wgEnotifMaxRecips, $wgAdditionalMailParams;
                $mime = null;

                $replyto = isset( $options['replyTo'] ) ? $options['replyTo'] : null;
                $contentType = isset( $options['contentType'] ) ?
                        $options['contentType'] : 'text/plain; charset=UTF-8';
                $headers = isset( $options['headers'] ) ? $options['headers'] : [];

                // Allow transformation of content, such as encrypting/signing
                $error = false;
                if ( !Hooks::run( 'UserMailerTransformContent', [ $to, $from, &$body, &$error ] ) ) {
                        if ( $error ) {
                                return Status::newFatal( 'php-mail-error', $error );
                        } else {
                                return Status::newFatal( 'php-mail-error-unknown' );
                        }
                }

                /**
                 * Forge email headers
                 * -------------------
                 *
                 * WARNING
                 *
                 * DO NOT add To: or Subject: headers at this step. They need to be
                 * handled differently depending upon the mailer we are going to use.
                 *
                 * To:
                 *  PHP mail() first argument is the mail receiver. The argument is
                 *  used as a recipient destination and as a To header.
                 *
                 *  PEAR mailer has a recipient argument which is only used to
                 *  send the mail. If no To header is given, PEAR will set it to
                 *  to 'undisclosed-recipients:'.
                 *
                 *  NOTE: To: is for presentation, the actual recipient is specified
                 *  by the mailer using the Rcpt-To: header.
                 *
                 * Subject:
                 *  PHP mail() second argument to pass the subject, passing a Subject
                 *  as an additional header will result in a duplicate header.
                 *
                 *  PEAR mailer should be passed a Subject header.
                 *
                 * -- hashar 20120218
                 */

                $headers['From'] = $from->toString();
                $returnPath = $from->address;
                $extraParams = $wgAdditionalMailParams;

                // Hook to generate custom VERP address for 'Return-Path'
                Hooks::run( 'UserMailerChangeReturnPath', [ $to, &$returnPath ] );
                // Add the envelope sender address using the -f command line option when PHP mail() is used.
                // Will default to the $from->address when the UserMailerChangeReturnPath hook fails and the
                // generated VERP address when the hook runs effectively.

                // PHP runs this through escapeshellcmd(). However that's not sufficient
                // escaping (e.g. due to spaces). MediaWiki's email sanitizer should generally
                // be good enough, but just in case, put in double quotes, and remove any
                // double quotes present (" is not allowed in emails, so should have no
                // effect, although this might cause apostrophees to be double escaped)
                $returnPathCLI = '"' . str_replace( '"', '', $returnPath ) . '"';
                $extraParams .= ' -f ' . $returnPathCLI;

                $headers['Return-Path'] = $returnPath;

                if ( $replyto ) {
                        $headers['Reply-To'] = $replyto->toString();
                }

                $headers['Date'] = MWTimestamp::getLocalInstance()->format( 'r' );
                $headers['Message-ID'] = self::makeMsgId();
                $headers['X-Mailer'] = 'MediaWiki mailer';
                $headers['List-Unsubscribe'] = '<' . SpecialPage::getTitleFor( 'Preferences' )
                        ->getFullURL( '', false, PROTO_CANONICAL ) . '>';

                // Line endings need to be different on Unix and Windows due to
                // the bug described at https://core.trac.wordpress.org/ticket/2603
                $endl = PHP_EOL;

                if ( is_array( $body ) ) {
                        // we are sending a multipart message
                        wfDebug( "Assembling multipart mime email\n" );
                        if ( !stream_resolve_include_path( 'Mail/mime.php' ) ) {
                                wfDebug( "PEAR Mail_Mime package is not installed. Falling back to text email.\n" );
                                // remove the html body for text email fall back
                                $body = $body['text'];
                        } else {
                                // Check if pear/mail_mime is already loaded (via composer)
                                if ( !class_exists( 'Mail_mime' ) ) {
                                        require_once 'Mail/mime.php';
                                }
                                if ( wfIsWindows() ) {
                                        $body['text'] = str_replace( "\n", "\r\n", $body['text'] );
                                        $body['html'] = str_replace( "\n", "\r\n", $body['html'] );
                                }
                                $mime = new Mail_mime( [
                                        'eol' => $endl,
                                        'text_charset' => 'UTF-8',
                                        'html_charset' => 'UTF-8'
                                ] );
                                $mime->setTXTBody( $body['text'] );
                                $mime->setHTMLBody( $body['html'] );
                                $body = $mime->get(); // must call get() before headers()
                                $headers = $mime->headers( $headers );
                        }
                }
                if ( $mime === null ) {
                        // sending text only, either deliberately or as a fallback
                        if ( wfIsWindows() ) {
                                $body = str_replace( "\n", "\r\n", $body );
                        }
                        $headers['MIME-Version'] = '1.0';
                        $headers['Content-type'] = $contentType;
                        $headers['Content-transfer-encoding'] = '8bit';
                }

                // allow transformation of MIME-encoded message
                if ( !Hooks::run( 'UserMailerTransformMessage',
                        [ $to, $from, &$subject, &$headers, &$body, &$error ] )
                ) {
                        if ( $error ) {
                                return Status::newFatal( 'php-mail-error', $error );
                        } else {
                                return Status::newFatal( 'php-mail-error-unknown' );
                        }
                }

                $ret = Hooks::run( 'AlternateUserMailer', [ $headers, $to, $from, $subject, $body ] );
                if ( $ret === false ) {
                        // the hook implementation will return false to skip regular mail sending
                        return Status::newGood();
                } elseif ( $ret !== true ) {
                        // the hook implementation will return a string to pass an error message
                        return Status::newFatal( 'php-mail-error', $ret );
                }

                if ( is_array( $wgSMTP ) ) {
                        // Check if pear/mail is already loaded (via composer)
                        if ( !class_exists( 'Mail' ) ) {
                                // PEAR MAILER
                                if ( !stream_resolve_include_path( 'Mail.php' ) ) {
                                        throw new MWException( 'PEAR mail package is not installed' );
                                }
                                require_once 'Mail.php';
                        }

                        MediaWiki\suppressWarnings();

                        // Create the mail object using the Mail::factory method
                        $mail_object =& Mail::factory( 'smtp', $wgSMTP );
                        if ( PEAR::isError( $mail_object ) ) {
                                wfDebug( "PEAR::Mail factory failed: " . $mail_object->getMessage() . "\n" );
                                MediaWiki\restoreWarnings();
                                return Status::newFatal( 'pear-mail-error', $mail_object->getMessage() );
                        }

                        wfDebug( "Sending mail via PEAR::Mail\n" );

                        $headers['Subject'] = self::quotedPrintable( $subject );

                        // When sending only to one recipient, shows it its email using To:
                        if ( count( $to ) == 1 ) {
                                $headers['To'] = $to[0]->toString();
                        }

                        // Split jobs since SMTP servers tends to limit the maximum
                        // number of possible recipients.
                        $chunks = array_chunk( $to, $wgEnotifMaxRecips );
                        foreach ( $chunks as $chunk ) {
                                $status = self::sendWithPear( $mail_object, $chunk, $headers, $body );
                                // FIXME : some chunks might be sent while others are not!
                                if ( !$status->isOK() ) {
                                        MediaWiki\restoreWarnings();
                                        return $status;
                                }
                        }
                        MediaWiki\restoreWarnings();
                        return Status::newGood();
                } else {
                        // PHP mail()
                        if ( count( $to ) > 1 ) {
                                $headers['To'] = 'undisclosed-recipients:;';
                        }
                        $headers = self::arrayToHeaderString( $headers, $endl );

                        wfDebug( "Sending mail via internal mail() function\n" );

                        self::$mErrorString = '';
                        $html_errors = ini_get( 'html_errors' );
                        ini_set( 'html_errors', '0' );
                        set_error_handler( 'UserMailer::errorHandler' );

                        try {
                                foreach ( $to as $recip ) {
                                        $sent = mail(
                                                $recip,
                                                self::quotedPrintable( $subject ),
                                                $body,
                                                $headers,
                                                $extraParams
                                        );
                                }
                        } catch ( Exception $e ) {
                                restore_error_handler();
                                throw $e;
                        }

                        restore_error_handler();
                        ini_set( 'html_errors', $html_errors );

                        if ( self::$mErrorString ) {
                                wfDebug( "Error sending mail: " . self::$mErrorString . "\n" );
                                return Status::newFatal( 'php-mail-error', self::$mErrorString );
                        } elseif ( !$sent ) {
                                // mail function only tells if there's an error
                                wfDebug( "Unknown error sending mail\n" );
                                return Status::newFatal( 'php-mail-error-unknown' );
                        } else {
                                return Status::newGood();
                        }
                }
        }

        /**
         * Set the mail error message in self::$mErrorString
         *
         * @param int $code Error number
         * @param string $string Error message
         */
        static function errorHandler( $code, $string ) {
                self::$mErrorString = preg_replace( '/^mail\(\)(\s*\[.*?\])?: /', '', $string );
        }

        /**
         * Strips bad characters from a header value to prevent PHP mail header injection attacks
         * @param string $val String to be santizied
         * @return string
         */
        public static function sanitizeHeaderValue( $val ) {
                return strtr( $val, [ "\r" => '', "\n" => '' ] );
        }

        /**
         * Converts a string into a valid RFC 822 "phrase", such as is used for the sender name
         * @param string $phrase
         * @return string
         */
        public static function rfc822Phrase( $phrase ) {
                // Remove line breaks
                $phrase = self::sanitizeHeaderValue( $phrase );
                // Remove quotes
                $phrase = str_replace( '"', '', $phrase );
                return '"' . $phrase . '"';
        }

        /**
         * Converts a string into quoted-printable format
         * @since 1.17
         *
         * From PHP5.3 there is a built in function quoted_printable_encode()
         * This method does not duplicate that.
         * This method is doing Q encoding inside encoded-words as defined by RFC 2047
         * This is for email headers.
         * The built in quoted_printable_encode() is for email bodies
         * @param string $string
         * @param string $charset
         * @return string
         */
        public static function quotedPrintable( $string, $charset = '' ) {
                // Probably incomplete; see RFC 2045
                if ( empty( $charset ) ) {
                        $charset = 'UTF-8';
                }
                $charset = strtoupper( $charset );
                $charset = str_replace( 'ISO-8859', 'ISO8859', $charset ); // ?

                $illegal = '\x00-\x08\x0b\x0c\x0e-\x1f\x7f-\xff=';
                $replace = $illegal . '\t ?_';
                if ( !preg_match( "/[$illegal]/", $string ) ) {
                        return $string;
                }
                $out = "=?$charset?Q?";
                $out .= preg_replace_callback( "/([$replace])/",
                        function ( $matches ) {
                                return sprintf( "=%02X", ord( $matches[1] ) );
                        },
                        $string
                );
                $out .= '?=';
                return $out;
        }
}