<?php
/**
* Miccrosoft BLOB Formatted RSA Key Handler
*
* More info:
*
* https://msdn.microsoft.com/en-us/library/windows/desktop/aa375601(v=vs.85).aspx
*
* PHP version 5
*
* @author Jim Wigginton <[email protected]>
* @copyright 2015 Jim Wigginton
* @license http://www.opensource.org/licenses/mit-license.html MIT License
* @link http://phpseclib.sourceforge.net
*/
namespace phpseclib3\Crypt\RSA\Formats\Keys;
use phpseclib3\Common\Functions\Strings;
use phpseclib3\Exception\UnsupportedFormatException;
use phpseclib3\Math\BigInteger;
/**
* Microsoft BLOB Formatted RSA Key Handler
*
* @author Jim Wigginton <[email protected]>
*/
abstract class MSBLOB
{
/**
* Public/Private Key Pair
*
*/
const PRIVATEKEYBLOB = 0x7;
/**
* Public Key
*
*/
const PUBLICKEYBLOB = 0x6;
/**
* Public Key
*
*/
const PUBLICKEYBLOBEX = 0xA;
/**
* RSA public key exchange algorithm
*
*/
const CALG_RSA_KEYX = 0x0000A400;
/**
* RSA public key exchange algorithm
*
*/
const CALG_RSA_SIGN = 0x00002400;
/**
* Public Key
*
*/
const RSA1 = 0x31415352;
/**
* Private Key
*
*/
const RSA2 = 0x32415352;
/**
* Break a public or private key down into its constituent components
*
* @param string $key
* @param string $password optional
* @return array
*/
public static function load($key, $password = '')
{
if (!Strings::is_stringable($key)) {
throw new \UnexpectedValueException('Key should be a string - not a ' . gettype($key));
}
$key = Strings::base64_decode($key);
if (!is_string($key)) {
throw new \UnexpectedValueException('Base64 decoding produced an error');
}
if (strlen($key) < 20) {
throw new \UnexpectedValueException('Key appears to be malformed');
}
// PUBLICKEYSTRUC publickeystruc
// https://msdn.microsoft.com/en-us/library/windows/desktop/aa387453(v=vs.85).aspx
extract(unpack('atype/aversion/vreserved/Valgo', Strings::shift($key, 8)));
/**
* @var string $type
* @var string $version
* @var integer $reserved
* @var integer $algo
*/
switch (ord($type)) {
case self::PUBLICKEYBLOB:
case self::PUBLICKEYBLOBEX:
$publickey = true;
break;
case self::PRIVATEKEYBLOB:
$publickey = false;
break;
default:
throw new \UnexpectedValueException('Key appears to be malformed');
}
$components = ['isPublicKey' => $publickey];
// https://msdn.microsoft.com/en-us/library/windows/desktop/aa375549(v=vs.85).aspx
switch ($algo) {
case self::CALG_RSA_KEYX:
case self::CALG_RSA_SIGN:
break;
default:
throw new \UnexpectedValueException('Key appears to be malformed');
}
// RSAPUBKEY rsapubkey
// https://msdn.microsoft.com/en-us/library/windows/desktop/aa387685(v=vs.85).aspx
// could do V for pubexp but that's unsigned 32-bit whereas some PHP installs only do signed 32-bit
extract(unpack('Vmagic/Vbitlen/a4pubexp', Strings::shift($key, 12)));
/**
* @var integer $magic
* @var integer $bitlen
* @var string $pubexp
*/
switch ($magic) {
case self::RSA2:
$components['isPublicKey'] = false;
// fall-through
case self::RSA1:
break;
default:
throw new \UnexpectedValueException('Key appears to be malformed');
}
$baseLength = $bitlen / 16;
if (strlen($key) != 2 * $baseLength && strlen($key) != 9 * $baseLength) {
throw new \UnexpectedValueException('Key appears to be malformed');
}
$components[$components['isPublicKey'] ? 'publicExponent' : 'privateExponent'] = new BigInteger(strrev($pubexp), 256);
// BYTE modulus[rsapubkey.bitlen/8]
$components['modulus'] = new BigInteger(strrev(Strings::shift($key, $bitlen / 8)), 256);
if ($publickey) {
return $components;
}
$components['isPublicKey'] = false;
// BYTE prime1[rsapubkey.bitlen/16]
$components['primes'] = [1 => new BigInteger(strrev(Strings::shift($key, $bitlen / 16)), 256)];
// BYTE prime2[rsapubkey.bitlen/16]
$components['primes'][] = new BigInteger(strrev(Strings::shift($key, $bitlen / 16)), 256);
// BYTE exponent1[rsapubkey.bitlen/16]
$components['exponents'] = [1 => new BigInteger(strrev(Strings::shift($key, $bitlen / 16)), 256)];
// BYTE exponent2[rsapubkey.bitlen/16]
$components['exponents'][] = new BigInteger(strrev(Strings::shift($key, $bitlen / 16)), 256);
// BYTE coefficient[rsapubkey.bitlen/16]
$components['coefficients'] = [2 => new BigInteger(strrev(Strings::shift($key, $bitlen / 16)), 256)];
if (isset($components['privateExponent'])) {
$components['publicExponent'] = $components['privateExponent'];
}
// BYTE privateExponent[rsapubkey.bitlen/8]
$components['privateExponent'] = new BigInteger(strrev(Strings::shift($key, $bitlen / 8)), 256);
return $components;
}
/**
* Convert a private key to the appropriate format.
*
* @param BigInteger $n
* @param BigInteger $e
* @param BigInteger $d
* @param array $primes
* @param array $exponents
* @param array $coefficients
* @param string $password optional
* @return string
*/
public static function savePrivateKey(BigInteger $n, BigInteger $e, BigInteger $d, array $primes, array $exponents, array $coefficients, $password = '')
{
if (count($primes) != 2) {
throw new \InvalidArgumentException('MSBLOB does not support multi-prime RSA keys');
}
if (!empty($password) && is_string($password)) {
throw new UnsupportedFormatException('MSBLOB private keys do not support encryption');
}
$n = strrev($n->toBytes());
$e = str_pad(strrev($e->toBytes()), 4, "\0");
$key = pack('aavV', chr(self::PRIVATEKEYBLOB), chr(2), 0, self::CALG_RSA_KEYX);
$key .= pack('VVa*', self::RSA2, 8 * strlen($n), $e);
$key .= $n;
$key .= strrev($primes[1]->toBytes());
$key .= strrev($primes[2]->toBytes());
$key .= strrev($exponents[1]->toBytes());
$key .= strrev($exponents[2]->toBytes());
$key .= strrev($coefficients[2]->toBytes());
$key .= strrev($d->toBytes());
return Strings::base64_encode($key);
}
/**
* Convert a public key to the appropriate format
*
* @param BigInteger $n
* @param BigInteger $e
* @return string
*/
public static function savePublicKey(BigInteger $n, BigInteger $e)
{
$n = strrev($n->toBytes());
$e = str_pad(strrev($e->toBytes()), 4, "\0");
$key = pack('aavV', chr(self::PUBLICKEYBLOB), chr(2), 0, self::CALG_RSA_KEYX);
$key .= pack('VVa*', self::RSA1, 8 * strlen($n), $e);
$key .= $n;
return Strings::base64_encode($key);
}
}