core\common\OutsideComm::mailAddressValidSecure()

Complexity

Conditions	15
Paths	58

Size

Total Lines	68
Code Lines	43

Duplication

Lines	0
Ratio	0 %

Importance

Changes

0

<?php
    public static function mailAddressValidSecure($address) {
        $loggerInstance = new \core\common\Logging();
        if (!filter_var($address, FILTER_VALIDATE_EMAIL)) {
            $loggerInstance->debug(4, "OutsideComm::mailAddressValidSecure: invalid mail address.");
            return OutsideComm::MAILDOMAIN_INVALID;
        }
        $domain = substr($address, strpos($address, '@') + 1); // everything after the @ sign
        // we can be sure that the @ was found (FILTER_VALIDATE_EMAIL succeeded)
        // but let's be explicit
        if ($domain === FALSE) {
            return OutsideComm::MAILDOMAIN_INVALID;
        }
        // does the domain have MX records?
        $mx = dns_get_record($domain, DNS_MX);
        if ($mx === FALSE) {
            $loggerInstance->debug(4, "OutsideComm::mailAddressValidSecure: no MX.");
            return OutsideComm::MAILDOMAIN_NO_MX;
        }
        $loggerInstance->debug(5, "Domain: $domain MX: " . print_r($mx, TRUE));
        // create a pool of A and AAAA records for all the MXes
        $ipAddrs = [];
        foreach ($mx as $onemx) {
            $v4list = dns_get_record($onemx['target'], DNS_A);
            $v6list = dns_get_record($onemx['target'], DNS_AAAA);
            foreach ($v4list as $oneipv4) {
                $ipAddrs[] = $oneipv4['ip'];
            }
            foreach ($v6list as $oneipv6) {
                $ipAddrs[] = "[" . $oneipv6['ipv6'] . "]";
            }
        }
        if (count($ipAddrs) == 0) {
            $loggerInstance->debug(4, "OutsideComm::mailAddressValidSecure: no mailserver hosts.");
            return OutsideComm::MAILDOMAIN_NO_HOST;
        }
        $loggerInstance->debug(5, "Domain: $domain Addrs: " . print_r($ipAddrs, TRUE));
        // connect to all hosts. If all can't connect, return MAILDOMAIN_NO_CONNECT. 
        // If at least one does not support STARTTLS or one of the hosts doesn't connect
        // , return MAILDOMAIN_NO_STARTTLS (one which we can't connect to we also
        // can't verify if it's doing STARTTLS, so better safe than sorry.
        $retval = OutsideComm::MAILDOMAIN_NO_CONNECT;
        $allWithStarttls = TRUE;
        foreach ($ipAddrs as $oneip) {
            $loggerInstance->debug(5, "OutsideComm::mailAddressValidSecure: connecting to $oneip.");
            $smtp = new \PHPMailer\PHPMailer\SMTP;
            if ($smtp->connect($oneip, 25)) {
                // host reached! so at least it's not a NO_CONNECT
                $loggerInstance->debug(4, "OutsideComm::mailAddressValidSecure: connected to $oneip.");
                $retval = OutsideComm::MAILDOMAIN_NO_STARTTLS;
                if ($smtp->hello('eduroam.org')) {
                    $extensions = $smtp->getServerExtList(); // Scrutinzer is wrong; is not always null - contains server capabilities
                    if (!is_array($extensions) || !array_key_exists('STARTTLS', $extensions)) {
                        $loggerInstance->debug(4, "OutsideComm::mailAddressValidSecure: no indication for STARTTLS.");
                        $allWithStarttls = FALSE;
                    }
                }
            } else {
                // no connect: then we can't claim all targets have STARTTLS
                $allWithStarttls = FALSE;
                $loggerInstance->debug(5, "OutsideComm::mailAddressValidSecure: failed $oneip.");
            }
        }
        // did the state $allWithStarttls survive? Then up the response to
        // appropriate level.
        if ($retval == OutsideComm::MAILDOMAIN_NO_STARTTLS && $allWithStarttls) {
            $retval = OutsideComm::MAILDOMAIN_STARTTLS;
        }
        return $retval;
    }