Viewing file:  DNSCheckValidation.php (5.65 KB) -rw-r--r--
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<?php
namespace Egulias\EmailValidator\Validation;
use Egulias\EmailValidator\EmailLexer;
use Egulias\EmailValidator\Result\InvalidEmail;
use Egulias\EmailValidator\Result\Reason\DomainAcceptsNoMail;
use Egulias\EmailValidator\Result\Reason\LocalOrReservedDomain;
use Egulias\EmailValidator\Result\Reason\NoDNSRecord as ReasonNoDNSRecord;
use Egulias\EmailValidator\Result\Reason\UnableToGetDNSRecord;
use Egulias\EmailValidator\Warning\NoDNSMXRecord;
use Egulias\EmailValidator\Warning\Warning;
class DNSCheckValidation implements EmailValidation
{
/**
* Reserved Top Level DNS Names (https://tools.ietf.org/html/rfc2606#section-2),
* mDNS and private DNS Namespaces (https://tools.ietf.org/html/rfc6762#appendix-G)
*
* @var string[]
*/
public const RESERVED_DNS_TOP_LEVEL_NAMES = [
// Reserved Top Level DNS Names
'test',
'example',
'invalid',
'localhost',
// mDNS
'local',
// Private DNS Namespaces
'intranet',
'internal',
'private',
'corp',
'home',
'lan',
];
/**
* @var Warning[]
*/
private $warnings = [];
/**
* @var InvalidEmail|null
*/
private $error;
/**
* @var array
*/
private $mxRecords = [];
/**
* @var DNSGetRecordWrapper
*/
private $dnsGetRecord;
public function __construct(?DNSGetRecordWrapper $dnsGetRecord = null)
{
if (!function_exists('idn_to_ascii')) {
throw new \LogicException(sprintf('The %s class requires the Intl extension.', __CLASS__));
}
if ($dnsGetRecord == null) {
$dnsGetRecord = new DNSGetRecordWrapper();
}
$this->dnsGetRecord = $dnsGetRecord;
}
public function isValid(string $email, EmailLexer $emailLexer): bool
{
// use the input to check DNS if we cannot extract something similar to a domain
$host = $email;
// Arguable pattern to extract the domain. Not aiming to validate the domain nor the email
if (false !== $lastAtPos = strrpos($email, '@')) {
$host = substr($email, $lastAtPos + 1);
}
// Get the domain parts
$hostParts = explode('.', $host);
$isLocalDomain = count($hostParts) <= 1;
$isReservedTopLevel = in_array($hostParts[(count($hostParts) - 1)], self::RESERVED_DNS_TOP_LEVEL_NAMES, true);
// Exclude reserved top level DNS names
if ($isLocalDomain || $isReservedTopLevel) {
$this->error = new InvalidEmail(new LocalOrReservedDomain(), $host);
return false;
}
return $this->checkDns($host);
}
public function getError(): ?InvalidEmail
{
return $this->error;
}
/**
* @return Warning[]
*/
public function getWarnings(): array
{
return $this->warnings;
}
/**
* @param string $host
*
* @return bool
*/
protected function checkDns($host)
{
$variant = INTL_IDNA_VARIANT_UTS46;
$host = rtrim(idn_to_ascii($host, IDNA_DEFAULT, $variant), '.');
$hostParts = explode('.', $host);
$host = array_pop($hostParts);
while (count($hostParts) > 0) {
$host = array_pop($hostParts) . '.' . $host;
if ($this->validateDnsRecords($host)) {
return true;
}
}
return false;
}
/**
* Validate the DNS records for given host.
*
* @param string $host A set of DNS records in the format returned by dns_get_record.
*
* @return bool True on success.
*/
private function validateDnsRecords($host): bool
{
$dnsRecordsResult = $this->dnsGetRecord->getRecords($host, DNS_A + DNS_MX);
if ($dnsRecordsResult->withError()) {
$this->error = new InvalidEmail(new UnableToGetDNSRecord(), '');
return false;
}
$dnsRecords = $dnsRecordsResult->getRecords();
// Combined check for A+MX+AAAA can fail with SERVFAIL, even in the presence of valid A/MX records
$aaaaRecordsResult = $this->dnsGetRecord->getRecords($host, DNS_AAAA);
if (! $aaaaRecordsResult->withError()) {
$dnsRecords = array_merge($dnsRecords, $aaaaRecordsResult->getRecords());
}
// No MX, A or AAAA DNS records
if ($dnsRecords === []) {
$this->error = new InvalidEmail(new ReasonNoDNSRecord(), '');
return false;
}
// For each DNS record
foreach ($dnsRecords as $dnsRecord) {
if (!$this->validateMXRecord($dnsRecord)) {
// No MX records (fallback to A or AAAA records)
if (empty($this->mxRecords)) {
$this->warnings[NoDNSMXRecord::CODE] = new NoDNSMXRecord();
}
return false;
}
}
return true;
}
/**
* Validate an MX record
*
* @param array $dnsRecord Given DNS record.
*
* @return bool True if valid.
*/
private function validateMxRecord($dnsRecord): bool
{
if (!isset($dnsRecord['type'])) {
$this->error = new InvalidEmail(new ReasonNoDNSRecord(), '');
return false;
}
if ($dnsRecord['type'] !== 'MX') {
return true;
}
// "Null MX" record indicates the domain accepts no mail (https://tools.ietf.org/html/rfc7505)
if (empty($dnsRecord['target']) || $dnsRecord['target'] === '.') {
$this->error = new InvalidEmail(new DomainAcceptsNoMail(), "");
return false;
}
$this->mxRecords[] = $dnsRecord;
return true;
}
}
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