static function parse(&$input)
{
$s2k = new S2K();
switch ($s2k->type = ord($input[0])) {
case 0:
$s2k->hash_algorithm = ord($input[1]);
$input = substr($input, 2);
break;
case 1:
$s2k->hash_algorithm = ord($input[1]);
$s2k->salt = substr($input, 2, 8);
$input = substr($input, 10);
break;
case 3:
$s2k->hash_algorithm = ord($input[1]);
$s2k->salt = substr($input, 2, 8);
$s2k->count = \OpenPGP\Util::decode_s2k_count(ord($input[10]));
$input = substr($input, 11);
break;
}
return $s2k;
}
static function encode_s2k_count($iterations)
{
if ($iterations >= 65011712) {
return 255;
}
$count = $iterations >> 6;
$c = 0;
while ($count >= 32) {
$count = $count >> 1;
$c++;
}
$result = $c << 4 | $count - 16;
if (\OpenPGP\Util::decode_s2k_count($result) < $iterations) {
return $result + 1;
}
return $result;
}
