Completed
Push — master ( feba95...840d56 )
by Eduardo Gulias
13:06
created

DNSCheckValidation::checkDns()   A

Complexity

Conditions 2
Paths 2

Size

Total Lines 11

Duplication

Lines 0
Ratio 0 %

Code Coverage

Tests 7
CRAP Score 2

Importance

Changes 0
Metric Value
dl 0
loc 11
ccs 7
cts 7
cp 1
rs 9.9
c 0
b 0
f 0
cc 2
nc 2
nop 1
crap 2
1
<?php
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namespace Egulias\EmailValidator\Validation;
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use Egulias\EmailValidator\EmailLexer;
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use Egulias\EmailValidator\Exception\InvalidEmail;
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use Egulias\EmailValidator\Exception\LocalOrReservedDomain;
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use Egulias\EmailValidator\Exception\DomainAcceptsNoMail;
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use Egulias\EmailValidator\Warning\NoDNSMXRecord;
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use Egulias\EmailValidator\Exception\NoDNSRecord;
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class DNSCheckValidation implements EmailValidation
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{
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    /**
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     * @var array
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     */
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    private $warnings = [];
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    /**
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     * @var InvalidEmail|null
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     */
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    private $error;
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    /**
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     * @var array
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     */
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    private $mxRecords = [];
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    public function __construct()
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    {
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        if (!function_exists('idn_to_ascii')) {
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            throw new \LogicException(sprintf('The %s class requires the Intl extension.', __CLASS__));
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        }
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    }
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    public function isValid($email, EmailLexer $emailLexer)
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    {
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        // use the input to check DNS if we cannot extract something similar to a domain
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        $host = $email;
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        // Arguable pattern to extract the domain. Not aiming to validate the domain nor the email
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        if (false !== $lastAtPos = strrpos($email, '@')) {
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            $host = substr($email, $lastAtPos + 1);
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        }
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        // Get the domain parts
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        $hostParts = explode('.', $host);
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        // Reserved Top Level DNS Names (https://tools.ietf.org/html/rfc2606#section-2),
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        // mDNS and private DNS Namespaces (https://tools.ietf.org/html/rfc6762#appendix-G)
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        $reservedTopLevelDnsNames = [
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            // Reserved Top Level DNS Names
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            'test',
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            'example',
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            'invalid',
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            'localhost',
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            // mDNS
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            'local',
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            // Private DNS Namespaces
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            'intranet',
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            'internal',
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            'private',
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            'corp',
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            'home',
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            'lan',
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        ];
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        $isLocalDomain = count($hostParts) <= 1;
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        $isReservedTopLevel = in_array($hostParts[(count($hostParts) - 1)], $reservedTopLevelDnsNames, true);
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        // Exclude reserved top level DNS names
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        if ($isLocalDomain || $isReservedTopLevel) {
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            $this->error = new LocalOrReservedDomain();
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            return false;
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        }
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        return $this->checkDns($host);
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    }
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    public function getError()
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    {
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        return $this->error;
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    }
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    public function getWarnings()
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    {
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        return $this->warnings;
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    }
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    /**
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     * @param string $host
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     *
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     * @return bool
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     */
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    protected function checkDns($host)
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    {
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        $variant = INTL_IDNA_VARIANT_2003;
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        if (defined('INTL_IDNA_VARIANT_UTS46')) {
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            $variant = INTL_IDNA_VARIANT_UTS46;
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        }
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        $host = rtrim(idn_to_ascii($host, IDNA_DEFAULT, $variant), '.') . '.';
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        return $this->validateDnsRecords($host);
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    }
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    /**
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     * Validate the DNS records for given host.
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     *
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     * @param string $host A set of DNS records in the format returned by dns_get_record.
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     *
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     * @return bool True on success.
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     */
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    private function validateDnsRecords($host)
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    {
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        // Get all MX, A and AAAA DNS records for host
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        $dnsRecords = dns_get_record($host, DNS_MX + DNS_A + DNS_AAAA);
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        // No MX, A or AAAA DNS records
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        if (empty($dnsRecords)) {
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            $this->error = new NoDNSRecord();
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            return false;
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        }
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        // For each DNS record
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        foreach ($dnsRecords as $dnsRecord) {
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            if (!$this->validateMXRecord($dnsRecord)) {
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                return false;
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            }
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        }
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        // No MX records (fallback to A or AAAA records)
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        if (empty($this->mxRecords)) {
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            $this->warnings[NoDNSMXRecord::CODE] = new NoDNSMXRecord();
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        }
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        return true;
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    }
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    /**
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     * Validate an MX record
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     *
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     * @param array $dnsRecord Given DNS record.
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     *
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     * @return bool True if valid.
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     */
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    private function validateMxRecord($dnsRecord)
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    {
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        if ($dnsRecord['type'] !== 'MX') {
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            return true;
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        }
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        // "Null MX" record indicates the domain accepts no mail (https://tools.ietf.org/html/rfc7505)
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        if (empty($dnsRecord['target']) || $dnsRecord['target'] === '.') {
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            $this->error = new DomainAcceptsNoMail();
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            return false;
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        }
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        $this->mxRecords[] = $dnsRecord;
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        return true;
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    }
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}
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