<?php
/**
* XML Formatted RSA Key Handler
*
* More info:
*
* http://www.w3.org/TR/xmldsig-core/#sec-RSAKeyValue
* http://www.w3.org/TR/xkms2/#XKMS_2_0_Paragraph_269
* http://en.wikipedia.org/wiki/XML_Signature
* http://en.wikipedia.org/wiki/XKMS
*
* PHP version 5
*
* @author Jim Wigginton <terrafrost@php.net>
* @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\BadConfigurationException;
use phpseclib3\Exception\UnsupportedFormatException;
use phpseclib3\Math\BigInteger;
/**
* XML Formatted RSA Key Handler
*
* @author Jim Wigginton <terrafrost@php.net>
*/
abstract class XML
{
/**
* 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));
}
if (!class_exists('DOMDocument')) {
throw new BadConfigurationException('The dom extension is not setup correctly on this system');
}
$components = [
'isPublicKey' => false,
'primes' => [],
'exponents' => [],
'coefficients' => []
];
$use_errors = libxml_use_internal_errors(true);
$dom = new \DOMDocument();
if (substr($key, 0, 5) != '<?xml') {
$key = '<xml>' . $key . '</xml>';
}
if (!$dom->loadXML($key)) {
libxml_use_internal_errors($use_errors);
throw new \UnexpectedValueException('Key does not appear to contain XML');
}
$xpath = new \DOMXPath($dom);
$keys = ['modulus', 'exponent', 'p', 'q', 'dp', 'dq', 'inverseq', 'd'];
foreach ($keys as $key) {
// $dom->getElementsByTagName($key) is case-sensitive
$temp = $xpath->query("//*[translate(local-name(), 'ABCDEFGHIJKLMNOPQRSTUVWXYZ','abcdefghijklmnopqrstuvwxyz')='$key']");
if (!$temp->length) {
continue;
}
$value = new BigInteger(Strings::base64_decode($temp->item(0)->nodeValue), 256);
switch ($key) {
case 'modulus':
$components['modulus'] = $value;
break;
case 'exponent':
$components['publicExponent'] = $value;
break;
case 'p':
$components['primes'][1] = $value;
break;
case 'q':
$components['primes'][2] = $value;
break;
case 'dp':
$components['exponents'][1] = $value;
break;
case 'dq':
$components['exponents'][2] = $value;
break;
case 'inverseq':
$components['coefficients'][2] = $value;
break;
case 'd':
$components['privateExponent'] = $value;
}
}
libxml_use_internal_errors($use_errors);
foreach ($components as $key => $value) {
if (is_array($value) && !count($value)) {
unset($components[$key]);
}
}
if (isset($components['modulus']) && isset($components['publicExponent'])) {
if (count($components) == 3) {
$components['isPublicKey'] = true;
}
return $components;
}
throw new \UnexpectedValueException('Modulus / exponent not present');
}
/**
* Convert a private key to the appropriate format.
*
* @param \phpseclib3\Math\BigInteger $n
* @param \phpseclib3\Math\BigInteger $e
* @param \phpseclib3\Math\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('XML does not support multi-prime RSA keys');
}
if (!empty($password) && is_string($password)) {
throw new UnsupportedFormatException('XML private keys do not support encryption');
}
return "<RSAKeyPair>\r\n" .
' <Modulus>' . Strings::base64_encode($n->toBytes()) . "</Modulus>\r\n" .
' <Exponent>' . Strings::base64_encode($e->toBytes()) . "</Exponent>\r\n" .
' <P>' . Strings::base64_encode($primes[1]->toBytes()) . "</P>\r\n" .
' <Q>' . Strings::base64_encode($primes[2]->toBytes()) . "</Q>\r\n" .
' <DP>' . Strings::base64_encode($exponents[1]->toBytes()) . "</DP>\r\n" .
' <DQ>' . Strings::base64_encode($exponents[2]->toBytes()) . "</DQ>\r\n" .
' <InverseQ>' . Strings::base64_encode($coefficients[2]->toBytes()) . "</InverseQ>\r\n" .
' <D>' . Strings::base64_encode($d->toBytes()) . "</D>\r\n" .
'</RSAKeyPair>';
}
/**
* Convert a public key to the appropriate format
*
* @param \phpseclib3\Math\BigInteger $n
* @param \phpseclib3\Math\BigInteger $e
* @return string
*/
public static function savePublicKey(BigInteger $n, BigInteger $e)
{
return "<RSAKeyValue>\r\n" .
' <Modulus>' . Strings::base64_encode($n->toBytes()) . "</Modulus>\r\n" .
' <Exponent>' . Strings::base64_encode($e->toBytes()) . "</Exponent>\r\n" .
'</RSAKeyValue>';
}
}