voku / php-domain-parser

src/Pdp/Parser.php

<?php

declare(strict_types=1);

/**
 * PHP Domain Parser: Public Suffix List based URL parsing.
 *
 * @link      http://github.com/jeremykendall/php-domain-parser for the canonical source repository
 *
 * @copyright Copyright (c) 2014 Jeremy Kendall (http://about.me/jeremykendall)
 * @license   http://github.com/jeremykendall/php-domain-parser/blob/master/LICENSE MIT License
 */

namespace Pdp;

use Pdp\Exception\SeriouslyMalformedUrlException;
use Pdp\Uri\Url;
use Pdp\Uri\Url\Host;
use voku\helper\UTF8;

/**
 * Parser.
 *
 * This class is responsible for Public Suffix List based url parsing
 */
class Parser
{
  /**
   * @var string RFC 3986 compliant scheme regex pattern
   *
   * @see https://tools.ietf.org/html/rfc3986#section-3.1
   */
  const SCHEME_PATTERN = '#^([a-zA-Z][a-zA-Z0-9+\-.]*)://#';

  /**
   * @var string IP address regex pattern
   */
  const IP_ADDRESS_PATTERN = '/^(?:(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.){3}(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)$/';

  /**
   * @var PublicSuffixList Public Suffix List
   */
  protected $publicSuffixList;

  /**
   * @var bool Whether or not a host part has been normalized
   */
  protected $isNormalized = false;

  /**
   * @var PunycodeWrapper
   */
  private $punycodeWrapper;

  /**
   * Public constructor.
   *
   * @codeCoverageIgnore
   *
   * @param PublicSuffixList $publicSuffixList Instance of PublicSuffixList
   */
  public function __construct(PublicSuffixList $publicSuffixList)
  {
    $this->publicSuffixList = $publicSuffixList;
    $this->punycodeWrapper = new PunycodeWrapper();
  }

  /**
   * Parses url.
   *
   * @param string $url Url to parse
   *
   * @return Url Object representation of url
   */
  public function parseUrl($url): Url
  {
    $rawUrl = $url;
    $elem = [
        'scheme'   => null,
        'user'     => null,
        'pass'     => null,
        'host'     => null,
        'port'     => null,
        'path'     => null,
        'query'    => null,
        'fragment' => null,
    ];

    if (\preg_match(self::SCHEME_PATTERN, $url) === 0) {
      // Wacky scheme required to overcome parse_url behavior in PHP
      // See https://github.com/jeremykendall/php-domain-parser/issues/49
      $url = 'php-hack://' . \preg_replace('#^//#', '', $url, 1);
    }

    $parts = pdp_parse_url($url);

    if ($parts === false || !isset($parts['host'])) {
      throw new SeriouslyMalformedUrlException($rawUrl);
    }

    if ($parts['scheme'] === 'php-hack') {
      $parts['scheme'] = null;
    }

    /** @noinspection AdditionOperationOnArraysInspection */
    $elem = (array)$parts + $elem;

    $host = $this->parseHost($parts['host']);

    return new Url(
        $elem['scheme'],
        $elem['user'],
        $elem['pass'],
        $host,
        $elem['port'],
        $elem['path'],
        $elem['query'],
        $elem['fragment']
    );
  }

  /**
   * Parses host part of url.
   *
   * @param string $host Host part of url
   *
   * @return Host Object representation of host portion of url
   */
  public function parseHost(string $host): Host
  {
    $host = UTF8::strtolower($host);

    return new Host(
        $this->getSubdomain($host),
        $this->getRegistrableDomain($host),
        $this->getPublicSuffix($host),
        $host
    );
  }

  /**
   * Get the raw public suffix based on the cached public suffix list file.
   * Return false if the provided suffix is not included in the PSL.
   *
   * @param string $host The host to process
   *
   * @return string|false The suffix or false if suffix not included in the PSL
   */
  protected function getRawPublicSuffix(string $host)
  {
    $host = $this->normalize($host);

    $parts = \array_reverse(\explode('.', $host));
    $publicSuffix = [];
    $publicSuffixList = $this->publicSuffixList;

    foreach ($parts as $part) {
      if (
          \array_key_exists($part, $publicSuffixList)
          &&
          \array_key_exists('!', $publicSuffixList[$part])
      ) {
        break;
      }

      if (\array_key_exists($part, $publicSuffixList)) {
        \array_unshift($publicSuffix, $part);
        $publicSuffixList = $publicSuffixList[$part];
        continue;
      }

      if (\array_key_exists('*', $publicSuffixList)) {
        \array_unshift($publicSuffix, $part);
        $publicSuffixList = $publicSuffixList['*'];
        continue;
      }

      // Avoids improper parsing when $host's subdomain + public suffix ===
      // a valid public suffix (e.g. host 'us.example.com' and public suffix 'us.com')
      //
      // Added by @goodhabit in https://github.com/jeremykendall/php-domain-parser/pull/15
      // Resolves https://github.com/jeremykendall/php-domain-parser/issues/16
      break;
    }

    // If empty, then the suffix is not included in the PSL and is
    // considered "invalid". This also triggers algorithm rule #2: If no
    // rules match, the prevailing rule is "*".
    if (empty($publicSuffix)) {
      return false;
    }

    $suffix = \implode('.', \array_filter($publicSuffix, '\strlen'));

    return $this->denormalize($suffix);
  }

  /**
   * Returns the public suffix portion of provided host.
   *
   * @param string $host host
   *
   * @return string|null public suffix or null if host does not contain a public suffix
   */
  public function getPublicSuffix(string $host)
  {
    if (\strpos($host, '.') === 0) {
      return null;
    }

    // Fixes #22: If a single label domain makes it this far (e.g.,
    // localhost, foo, etc.), this stops it from incorrectly being set as
    // the public suffix.
    if (!$this->isMultiLabelDomain($host)) {
      return null;
    }

    // Fixes #43
    if ($this->isIpv4Address($host)) {
      return null;
    }

    $suffix = $this->getRawPublicSuffix($host);

    // Apply algorithm rule #2: If no rules match, the prevailing rule is "*".
    if (false === $suffix) {
      $parts = \array_reverse(explode('.', $host));
      $suffix = \array_shift($parts);
    }

    return $suffix;
  }

  /**
   * Is suffix valid?
   *
   * Validity determined by whether or not the suffix is included in the PSL.
   *
   * @param string $host Host part
   *
   * @return bool True is suffix is valid, false otherwise
   */
  public function isSuffixValid(string $host): bool
  {
    return $this->getRawPublicSuffix($host) !== false;
  }

  /**
   * Returns registrable domain portion of provided host.
   *
   * Per the test cases provided by Mozilla
   * (http://mxr.mozilla.org/mozilla-central/source/netwerk/test/unit/data/test_psl.txt?raw=1),
   * this method should return null if the domain provided is a public suffix.
   *
   * @param string|null $host host
   *
   * @return string|null registrable domain
   */
  public function getRegistrableDomain($host)
  {
    if (!$this->isMultiLabelDomain($host)) {
      return null;
    }

    $publicSuffix = $this->getPublicSuffix($host);

    if ($publicSuffix === null || $host == $publicSuffix) {
      return null;
    }

    $publicSuffixParts = \array_reverse(\explode('.', $publicSuffix));
    $hostParts = \array_reverse(\explode('.', $host));
    $registrableDomainParts = $publicSuffixParts + \array_slice($hostParts, 0, \count($publicSuffixParts) + 1);

    return \implode('.', \array_reverse($registrableDomainParts));
  }

  /**
   * Returns the subdomain portion of provided host.
   *
   * @param string $host host
   *
   * @return string|null subdomain
   */
  public function getSubdomain(string $host)
  {
    $registrableDomain = $this->getRegistrableDomain($host);

    if ($registrableDomain === null || $host === $registrableDomain) {
      return null;
    }

    $registrableDomainParts = \array_reverse(\explode('.', $registrableDomain));

    $host = $this->normalize($host);

    $hostParts = \array_reverse(\explode('.', $host));
    $subdomainParts = \array_slice($hostParts, \count($registrableDomainParts));

    $subdomain = \implode('.', \array_reverse($subdomainParts));

    return $this->denormalize($subdomain);
  }

  /**
   * If a URL is not punycoded, then it may be an IDNA URL, so it must be
   * converted to ASCII. Performs conversion and sets flag.
   *
   * @param string $part Host part
   *
   * @return string Host part, transformed if not punycoded
   */
  protected function normalize(string $part): string
  {
    $punycoded = (\strpos($part, 'xn--') !== false);

    if ($punycoded === false) {
      $part = $this->punycodeWrapper->encode($part);
      $this->isNormalized = true;
    }

    return \strtolower($part);
  }

  /**
   * Converts any normalized part back to IDNA. Performs conversion and
   * resets flag.
   *
   * @param string $part Host part
   *
   * @return string Denormalized host part
   */
  protected function denormalize(string $part): string
  {
    if ($this->isNormalized === true) {
      $part = $this->punycodeWrapper->decode($part);
      $this->isNormalized = false;
    }

    return $part;
  }

  /**
   * Tests host for presence of '.'.
   *
   * Related to #22
   *
   * @param string|null $host Host part of url
   *
   * @return bool True if multi-label domain, false otherwise
   */
  protected function isMultiLabelDomain($host): bool
  {
    if (!$host) {

The expression $host of type string|null is loosely compared to false; this is ambiguous if the string can be empty. You might want to explicitly use === null instead.

      return false;
    }

    return \strpos($host, '.') !== false;
  }

  /**
   * Tests host to determine if it is an IP address.
   *
   * Related to #43
   *
   * @param string $host Host part of url
   *
   * @return bool True if host is an ip address, false otherwise
   */
  protected function isIpv4Address(string $host): bool
  {
    return \preg_match(self::IP_ADDRESS_PATTERN, $host) === 1;
  }
}