openpgp-php/lib/OpenPgP/SecretKeyPacket.php
2020-06-18 22:03:56 +10:00

80 lines
2.2 KiB
PHP

<?php
namespace Leenooks\OpenPGP;
/**
* OpenPGP Secret-Key packet (tag 5).
*
* @see http://tools.ietf.org/html/rfc4880#section-5.5.1.3
* @see http://tools.ietf.org/html/rfc4880#section-5.5.3
* @see http://tools.ietf.org/html/rfc4880#section-11.2
* @see http://tools.ietf.org/html/rfc4880#section-12
*/
class SecretKeyPacket extends PublicKeyPacket
{
protected $tag = 5;
public $s2k_useage, $s2k, $symmetric_algorithm, $private_hash, $encrypted_data;
static $secret_key_fields = array(
1 => array('d', 'p', 'q', 'u'), // RSA
2 => array('d', 'p', 'q', 'u'), // RSA-E
3 => array('d', 'p', 'q', 'u'), // RSA-S
16 => array('x'), // ELG-E
17 => array('x'), // DSA
);
function body()
{
$bytes = parent::body() . chr($this->s2k_useage);
$secret_material = NULL;
if($this->s2k_useage == 255 || $this->s2k_useage == 254) {
$bytes .= chr($this->symmetric_algorithm);
$bytes .= $this->s2k->to_bytes();
}
if($this->s2k_useage > 0) {
$bytes .= $this->encrypted_data;
} else {
$secret_material = '';
foreach(self::$secret_key_fields[$this->algorithm] as $f) {
$f = $this->key[$f];
$secret_material .= pack('n', \Leenooks\OpenPGP::bitlength($f));
$secret_material .= $f;
}
$bytes .= $secret_material;
// 2-octet checksum
$chk = 0;
for($i = 0; $i < strlen($secret_material); $i++) {
$chk = ($chk + ord($secret_material[$i])) % 65536;
}
$bytes .= pack('n', $chk);
}
return $bytes;
}
function key_from_input()
{
foreach(self::$secret_key_fields[$this->algorithm] as $field) {
$this->key[$field] = $this->read_mpi();
}
}
function read()
{
parent::read(); // All the fields from PublicKey
$this->s2k_useage = ord($this->read_byte());
if($this->s2k_useage == 255 || $this->s2k_useage == 254) {
$this->symmetric_algorithm = ord($this->read_byte());
$this->s2k = S2K::parse($this->input);
} else if($this->s2k_useage > 0) {
$this->symmetric_algorithm = $this->s2k_useage;
}
if($this->s2k_useage > 0) {
$this->encrypted_data = $this->input; // Rest of input is MPIs and checksum (encrypted)
} else {
$this->key_from_input();
$this->private_hash = $this->read_bytes(2); // TODO: Validate checksum?
}
}
}