idna.class.php

idna.class.php

<?php

class IDNA {
  public static function encode($string) {
    $parts = explode('.', $string);
    foreach ($parts as &$part) {
      $part = self::to_ascii($part);
      if ($part === false) return false;
    }
    return implode('.', $parts);
  }
  public static function to_ascii($string) {
    if (self::is_ascii($string)) return $string;
    if (strpos($string, "xn--") === 0) return false;
    $string = self::punycode_encode($string);
    return ($string !== false ? "xn--$string" : false);
  }
  protected static function is_ascii($string) {
    return (preg_match('/(?:[^\x00-\x7F])/', $string) !== 1);
  }
  protected static function utf8_to_codepoints($input) {
    $codepoints = array();
    $strlen = strlen($input);
    for ($position = 0; $position < $strlen; $position++) {
      $value = ord($input[$position]);
      if ((~$value & 0x80) === 0x80) {
        $character = $value;
        $length = 1;
        $remaining = 0;
      }
      elseif (($value & 0xE0) === 0xC0) {
        $character = ($value & 0x1F) << 6;
        $length = 2;
        $remaining = 1;
      }
      elseif (($value & 0xF0) === 0xE0) {
        $character = ($value & 0x0F) << 12;
        $length = 3;
        $remaining = 2;
      }
      elseif (($value & 0xF8) === 0xF0) {
        $character = ($value & 0x07) << 18;
        $length = 4;
        $remaining = 3;
      }
      else {
        return false;
      }
      if ($remaining > 0) {
        if ($position + $length > $strlen) return false;
        for ($position++; $remaining > 0; $position++) {
          $value = ord($input[$position]);
          if (($value & 0xC0) !== 0x80) {
            return false;
          }
          $character |= ($value & 0x3F) << (--$remaining * 6);
        }
        $position--;
      }
      if ($length > 1 && $character <= 0x7F || $length > 2 && $character <= 0x7FF || $length > 3 && $character <= 0xFFFF || 
      ($character & 0xFFFE) === 0xFFFE || $character >= 0xFDD0 && $character <= 0xFDEF || ($character > 0xD7FF && $character < 0xF900 || 
      $character < 0x20 || $character > 0x7E && $character < 0xA0 || $character > 0xEFFFD)) {
        return false;
      }
      $codepoints[] = $character;
    }
    return $codepoints;
  }
  public static function punycode_encode($input) {
    $output = '';
    $n = 128;
    $delta = 0;
    $bias = 72;
    $h = $b = 0;
    $digits = 'abcdefghijklmnopqrstuvwxyz0123456789';
    $extended = array();
    $codepoints = self::utf8_to_codepoints($input);
    if ($codepoints === false) return false;
    foreach ($codepoints as $char) {
      if ($char < 128) {
        $output .= chr($char);
        $h++;
      }
      elseif ($char < $n) {
        return false;
      }
      else {
        $extended[$char] = true;
      }
    }
    $extended = array_keys($extended);
    sort($extended);
    $b = $h;
    if (strlen($output) > 0) $output .= '-';
    while ($h < count($codepoints)) {
      $m = array_shift($extended);
      $delta += ($m - $n) * ($h + 1);
      $n = $m;
      for ($num = 0; $num < count($codepoints); $num++) {
        $c = $codepoints[$num];
        if ($c < $n) {
          $delta++;
        }
        elseif ($c === $n) {
          $q = $delta;
          for ($k = 36; ; $k += 36) {
            if ($k <= ($bias + 1)) {
              $t = 1;
            }
            elseif ($k >= ($bias + 26)) {
              $t = 26;
            }
            else {
              $t = $k - $bias;
            }
            if ($q < $t) {
              break;
            }
            $digit = $t + (($q - $t) % (36 - $t));
            $output .= $digits[$digit];
            $q = floor(($q - $t) / (36 - $t));
          }
          $output .= $digits[$q];
          $delta = ($h === $b) ? floor($delta / 700) : floor($delta / 2);
          $delta += floor($delta / ($h + 1));
          $i = 0;
          $max = floor(((36 - 1) * 26) / 2);
          while ($delta > $max) {
            $delta = floor($delta / (36 - 1));
            $i += 36;
          }
          $bias = $i + floor(((36 - 1 + 1) * $delta) / ($delta + 38));
          $delta = 0;
          $h++;
        }
      }
      $delta++;
      $n++;
    }
    return $output;
  }
}
if (!function_exists("idn_to_ascii")) {
  function idn_to_ascii($domain, $b=null, $c=null, $d=null) { return IDNA::encode($domain); }
}

?>