/**
* Creates a salt
*
* @return string
*/
public static function createSalt()
{
$salt = Random::createString(self::SALT_START_LENGTH);
$base64 = base64_encode($salt);
$salt = self::convertAlphabets($base64);
return Binary::getSlice($salt, 0, self::SALT_FINAL_LENGTH);
}
/**
* @param int $length
* @return string|null
*/
public static function dev($length)
{
if (!is_readable('/dev/urandom')) {
return null;
}
$fp = fopen('/dev/urandom', 'r');
$left = $length;
$result = [];
do {
$buffer = fread($fp, $left);
$lBuffer = Binary::getLength($buffer);
if ($lBuffer === 0) {
fclose($fp);
return null;
}
$result[] = $buffer;
$left -= $lBuffer;
} while ($left > 0);
fclose($fp);
return implode('', $result);
}
/**
* Returns an array of bytes
*
* @param int $count
* @return int[]
*/
public static function createBytes($count)
{
return Binary::unpackBytes(self::createString($count));
}
/**
* @param string $a
* @param string $b
* @return string
*/
public static function plus($a, $b)
{
$a = Binary::getByteFromChar($a);
$b = Binary::getByteFromChar($b);
return chr($a + $b);
}