<?php
/**
* UUID class
*
* The following class generates VALID RFC 4122 COMPLIANT
* Universally Unique IDentifiers (UUID) version 3, 4 and 5.
*
* UUIDs generated validates using OSSP UUID Tool, and output
* for named-based UUIDs are exactly the same. This is a pure
* PHP implementation.
*
* @author Andrew Moore
* @link http://www.php.net/manual/en/function.uniqid.php#94959
*/
class UUID
{
/**
* Generate v3 UUID
*
* Version 3 UUIDs are named based. They require a namespace (another
* valid UUID) and a value (the name). Given the same namespace and
* name, the output is always the same.
*
* @param uuid $namespace
* @param string $name
*/
public static function v3($namespace, $name)
{
if(!self::is_valid($namespace)) return false;
 
// Get hexadecimal components of namespace
$nhex = str_replace(array('-','{','}'), '', $namespace);
 
// Binary Value
$nstr = '';
 
// Convert Namespace UUID to bits
for($i = 0; $i < strlen($nhex); $i+=2)
{
$nstr .= chr(hexdec($nhex[$i].$nhex[$i+1]));
}
 
// Calculate hash value
$hash = md5($nstr . $name);
 
return sprintf('%08s-%04s-%04x-%04x-%12s',
 
// 32 bits for "time_low"
substr($hash, 0, 8),
 
// 16 bits for "time_mid"
substr($hash, 8, 4),
 
// 16 bits for "time_hi_and_version",
// four most significant bits holds version number 3
(hexdec(substr($hash, 12, 4)) & 0x0fff) | 0x3000,
 
// 16 bits, 8 bits for "clk_seq_hi_res",
// 8 bits for "clk_seq_low",
// two most significant bits holds zero and one for variant DCE1.1
(hexdec(substr($hash, 16, 4)) & 0x3fff) | 0x8000,
 
// 48 bits for "node"
substr($hash, 20, 12)
);
}
 
/**
*
* Generate v4 UUID
*
* Version 4 UUIDs are pseudo-random.
*/
public static function v4()
{
return sprintf('%04x%04x-%04x-%04x-%04x-%04x%04x%04x',
 
// 32 bits for "time_low"
mt_rand(0, 0xffff), mt_rand(0, 0xffff),
 
// 16 bits for "time_mid"
mt_rand(0, 0xffff),
 
// 16 bits for "time_hi_and_version",
// four most significant bits holds version number 4
mt_rand(0, 0x0fff) | 0x4000,
 
// 16 bits, 8 bits for "clk_seq_hi_res",
// 8 bits for "clk_seq_low",
// two most significant bits holds zero and one for variant DCE1.1
mt_rand(0, 0x3fff) | 0x8000,
 
// 48 bits for "node"
mt_rand(0, 0xffff), mt_rand(0, 0xffff), mt_rand(0, 0xffff)
);
}
 
/**
* Generate v5 UUID
*
* Version 5 UUIDs are named based. They require a namespace (another
* valid UUID) and a value (the name). Given the same namespace and
* name, the output is always the same.
*
* @param uuid $namespace
* @param string $name
*/
public static function v5($namespace, $name)
{
if(!self::is_valid($namespace)) return false;
 
// Get hexadecimal components of namespace
$nhex = str_replace(array('-','{','}'), '', $namespace);
 
// Binary Value
$nstr = '';
 
// Convert Namespace UUID to bits
for($i = 0; $i < strlen($nhex); $i+=2)
{
$nstr .= chr(hexdec($nhex[$i].$nhex[$i+1]));
}
 
// Calculate hash value
$hash = sha1($nstr . $name);
 
return sprintf('%08s-%04s-%04x-%04x-%12s',
 
// 32 bits for "time_low"
substr($hash, 0, 8),
 
// 16 bits for "time_mid"
substr($hash, 8, 4),
 
// 16 bits for "time_hi_and_version",
// four most significant bits holds version number 5
(hexdec(substr($hash, 12, 4)) & 0x0fff) | 0x5000,
 
// 16 bits, 8 bits for "clk_seq_hi_res",
// 8 bits for "clk_seq_low",
// two most significant bits holds zero and one for variant DCE1.1
(hexdec(substr($hash, 16, 4)) & 0x3fff) | 0x8000,
 
// 48 bits for "node"
substr($hash, 20, 12)
);
}
 
public static function is_valid($uuid) {
return preg_match('/^\{?[0-9a-f]{8}\-?[0-9a-f]{4}\-?[0-9a-f]{4}\-?'.
'[0-9a-f]{4}\-?[0-9a-f]{12}\}?$/i', $uuid) === 1;
}
}
?>