<?php
namespace TrueBV;
use TrueBV\Exception\DomainOutOfBoundsException;
use TrueBV\Exception\LabelOutOfBoundsException;
/**
* Punycode implementation as described in RFC 3492
*
* @link http://tools.ietf.org/html/rfc3492
*/
class Punycode
{
/**
* Bootstring parameter values
*
*/
const BASE = 36;
const TMIN = 1;
const TMAX = 26;
const SKEW = 38;
const DAMP = 700;
const INITIAL_BIAS = 72;
const INITIAL_N = 128;
const PREFIX = 'xn--';
const DELIMITER = '-';
/**
* Encode table
*
* @param array
*/
protected static $encodeTable = array(
'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l',
'm', 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x',
'y', 'z', '0', '1', '2', '3', '4', '5', '6', '7', '8', '9',
);
/**
* Decode table
*
* @param array
*/
protected static $decodeTable = array(
'a' => 0, 'b' => 1, 'c' => 2, 'd' => 3, 'e' => 4, 'f' => 5,
'g' => 6, 'h' => 7, 'i' => 8, 'j' => 9, 'k' => 10, 'l' => 11,
'm' => 12, 'n' => 13, 'o' => 14, 'p' => 15, 'q' => 16, 'r' => 17,
's' => 18, 't' => 19, 'u' => 20, 'v' => 21, 'w' => 22, 'x' => 23,
'y' => 24, 'z' => 25, '0' => 26, '1' => 27, '2' => 28, '3' => 29,
'4' => 30, '5' => 31, '6' => 32, '7' => 33, '8' => 34, '9' => 35
);
/**
* Character encoding
*
* @param string
*/
protected $encoding;
/**
* Constructor
*
* @param string $encoding Character encoding
*/
public function __construct($encoding = 'UTF-8')
{
$this->encoding = $encoding;
}
/**
* Encode a domain to its Punycode version
*
* @param string $input Domain name in Unicode to be encoded
* @return string Punycode representation in ASCII
*/
public function encode($input)
{
$input = mb_strtolower($input, $this->encoding);
$parts = explode('.', $input);
foreach ($parts as &$part) {
$length = strlen($part);
if ($length < 1) {
throw new LabelOutOfBoundsException(sprintf('The length of any one label is limited to between 1 and 63 octets, but %s given.', $length));
}
$part = $this->encodePart($part);
}
$output = implode('.', $parts);
$length = strlen($output);
if ($length > 255) {
throw new DomainOutOfBoundsException(sprintf('A full domain name is limited to 255 octets (including the separators), %s given.', $length));
}
return $output;
}
/**
* Encode a part of a domain name, such as tld, to its Punycode version
*
* @param string $input Part of a domain name
* @return string Punycode representation of a domain part
*/
protected function encodePart($input)
{
$codePoints = $this->listCodePoints($input);
$n = static::INITIAL_N;
$bias = static::INITIAL_BIAS;
$delta = 0;
$h = $b = count($codePoints['basic']);
$output = '';
foreach ($codePoints['basic'] as $code) {
$output .= $this->codePointToChar($code);
}
if ($input === $output) {
return $output;
}
if ($b > 0) {
$output .= static::DELIMITER;
}
$codePoints['nonBasic'] = array_unique($codePoints['nonBasic']);
sort($codePoints['nonBasic']);
$i = 0;
$length = mb_strlen($input, $this->encoding);
while ($h < $length) {
$m = $codePoints['nonBasic'][$i++];
$delta = $delta + ($m - $n) * ($h + 1);
$n = $m;
foreach ($codePoints['all'] as $c) {
if ($c < $n || $c < static::INITIAL_N) {
$delta++;
}
if ($c === $n) {
$q = $delta;
for ($k = static::BASE;; $k += static::BASE) {
$t = $this->calculateThreshold($k, $bias);
if ($q < $t) {
break;
}
$code = $t + (($q - $t) % (static::BASE - $t));
$output .= static::$encodeTable[$code];
$q = ($q - $t) / (static::BASE - $t);
}
$output .= static::$encodeTable[$q];
$bias = $this->adapt($delta, $h + 1, ($h === $b));
$delta = 0;
$h++;
}
}
$delta++;
$n++;
}
$out = static::PREFIX . $output;
$length = strlen($out);
if ($length > 63 || $length < 1) {
throw new LabelOutOfBoundsException(sprintf('The length of any one label is limited to between 1 and 63 octets, but %s given.', $length));
}
return $out;
}
/**
* Decode a Punycode domain name to its Unicode counterpart
*
* @param string $input Domain name in Punycode
* @return string Unicode domain name
*/
public function decode($input)
{
$input = strtolower($input);
$parts = explode('.', $input);
foreach ($parts as &$part) {
$length = strlen($part);
if ($length > 63 || $length < 1) {
throw new LabelOutOfBoundsException(sprintf('The length of any one label is limited to between 1 and 63 octets, but %s given.', $length));
}
if (strpos($part, static::PREFIX) !== 0) {
continue;
}
$part = substr($part, strlen(static::PREFIX));
$part = $this->decodePart($part);
}
$output = implode('.', $parts);
$length = strlen($output);
if ($length > 255) {
throw new DomainOutOfBoundsException(sprintf('A full domain name is limited to 255 octets (including the separators), %s given.', $length));
}
return $output;
}
/**
* Decode a part of domain name, such as tld
*
* @param string $input Part of a domain name
* @return string Unicode domain part
*/
protected function decodePart($input)
{
$n = static::INITIAL_N;
$i = 0;
$bias = static::INITIAL_BIAS;
$output = '';
$pos = strrpos($input, static::DELIMITER);
if ($pos !== false) {
$output = substr($input, 0, $pos++);
} else {
$pos = 0;
}
$outputLength = strlen($output);
$inputLength = strlen($input);
while ($pos < $inputLength) {
$oldi = $i;
$w = 1;
for ($k = static::BASE;; $k += static::BASE) {
$digit = static::$decodeTable[$input[$pos++]];
$i = $i + ($digit * $w);
$t = $this->calculateThreshold($k, $bias);
if ($digit < $t) {
break;
}
$w = $w * (static::BASE - $t);
}
$bias = $this->adapt($i - $oldi, ++$outputLength, ($oldi === 0));
$n = $n + (int) ($i / $outputLength);
$i = $i % ($outputLength);
$output = mb_substr($output, 0, $i, $this->encoding) . $this->codePointToChar($n) . mb_substr($output, $i, $outputLength - 1, $this->encoding);
$i++;
}
return $output;
}
/**
* Calculate the bias threshold to fall between TMIN and TMAX
*
* @param integer $k
* @param integer $bias
* @return integer
*/
protected function calculateThreshold($k, $bias)
{
if ($k <= $bias + static::TMIN) {
return static::TMIN;
} elseif ($k >= $bias + static::TMAX) {
return static::TMAX;
}
return $k - $bias;
}
/**
* Bias adaptation
*
* @param integer $delta
* @param integer $numPoints
* @param boolean $firstTime
* @return integer
*/
protected function adapt($delta, $numPoints, $firstTime)
{
$delta = (int) (
($firstTime)
? $delta / static::DAMP
: $delta / 2
);
$delta += (int) ($delta / $numPoints);
$k = 0;
while ($delta > ((static::BASE - static::TMIN) * static::TMAX) / 2) {
$delta = (int) ($delta / (static::BASE - static::TMIN));
$k = $k + static::BASE;
}
$k = $k + (int) (((static::BASE - static::TMIN + 1) * $delta) / ($delta + static::SKEW));
return $k;
}
/**
* List code points for a given input
*
* @param string $input
* @return array Multi-dimension array with basic, non-basic and aggregated code points
*/
protected function listCodePoints($input)
{
$codePoints = array(
'all' => array(),
'basic' => array(),
'nonBasic' => array(),
);
$length = mb_strlen($input, $this->encoding);
for ($i = 0; $i < $length; $i++) {
$char = mb_substr($input, $i, 1, $this->encoding);
$code = $this->charToCodePoint($char);
if ($code < 128) {
$codePoints['all'][] = $codePoints['basic'][] = $code;
} else {
$codePoints['all'][] = $codePoints['nonBasic'][] = $code;
}
}
return $codePoints;
}
/**
* Convert a single or multi-byte character to its code point
*
* @param string $char
* @return integer
*/
protected function charToCodePoint($char)
{
$code = ord($char[0]);
if ($code < 128) {
return $code;
} elseif ($code < 224) {
return (($code - 192) * 64) + (ord($char[1]) - 128);
} elseif ($code < 240) {
return (($code - 224) * 4096) + ((ord($char[1]) - 128) * 64) + (ord($char[2]) - 128);
} else {
return (($code - 240) * 262144) + ((ord($char[1]) - 128) * 4096) + ((ord($char[2]) - 128) * 64) + (ord($char[3]) - 128);
}
}
/**
* Convert a code point to its single or multi-byte character
*
* @param integer $code
* @return string
*/
protected function codePointToChar($code)
{
if ($code <= 0x7F) {
return chr($code);
} elseif ($code <= 0x7FF) {
return chr(($code >> 6) + 192) . chr(($code & 63) + 128);
} elseif ($code <= 0xFFFF) {
return chr(($code >> 12) + 224) . chr((($code >> 6) & 63) + 128) . chr(($code & 63) + 128);
} else {
return chr(($code >> 18) + 240) . chr((($code >> 12) & 63) + 128) . chr((($code >> 6) & 63) + 128) . chr(($code & 63) + 128);
}
}
}