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   1  <?php
   2  
   3  /**
   4   * OpenSSH Formatted DSA Key Handler
   5   *
   6   * PHP version 5
   7   *
   8   * Place in $HOME/.ssh/authorized_keys
   9   *
  10   * @category  Crypt
  11   * @package   DSA
  12   * @author    Jim Wigginton <[email protected]>
  13   * @copyright 2015 Jim Wigginton
  14   * @license   http://www.opensource.org/licenses/mit-license.html  MIT License
  15   * @link      http://phpseclib.sourceforge.net
  16   */
  17  
  18  namespace phpseclib3\Crypt\DSA\Formats\Keys;
  19  
  20  use phpseclib3\Common\Functions\Strings;
  21  use phpseclib3\Crypt\Common\Formats\Keys\OpenSSH as Progenitor;
  22  use phpseclib3\Math\BigInteger;
  23  
  24  /**
  25   * OpenSSH Formatted DSA Key Handler
  26   *
  27   * @package DSA
  28   * @author  Jim Wigginton <[email protected]>
  29   * @access  public
  30   */
  31  abstract class OpenSSH extends Progenitor
  32  {
  33      /**
  34       * Supported Key Types
  35       *
  36       * @var array
  37       */
  38      protected static $types = ['ssh-dss'];
  39  
  40      /**
  41       * Break a public or private key down into its constituent components
  42       *
  43       * @access public
  44       * @param string $key
  45       * @param string $password optional
  46       * @return array
  47       */
  48      public static function load($key, $password = '')
  49      {
  50          $parsed = parent::load($key, $password);
  51  
  52          if (isset($parsed['paddedKey'])) {
  53              list($type) = Strings::unpackSSH2('s', $parsed['paddedKey']);
  54              if ($type != $parsed['type']) {
  55                  throw new \RuntimeException("The public and private keys are not of the same type ($type vs $parsed[type])");
  56              }
  57  
  58              list($p, $q, $g, $y, $x, $comment) = Strings::unpackSSH2('i5s', $parsed['paddedKey']);
  59  
  60              return compact('p', 'q', 'g', 'y', 'x', 'comment');
  61          }
  62  
  63          list($p, $q, $g, $y) = Strings::unpackSSH2('iiii', $parsed['publicKey']);
  64  
  65          $comment = $parsed['comment'];
  66  
  67          return compact('p', 'q', 'g', 'y', 'comment');
  68      }
  69  
  70      /**
  71       * Convert a public key to the appropriate format
  72       *
  73       * @access public
  74       * @param \phpseclib3\Math\BigInteger $p
  75       * @param \phpseclib3\Math\BigInteger $q
  76       * @param \phpseclib3\Math\BigInteger $g
  77       * @param \phpseclib3\Math\BigInteger $y
  78       * @param array $options optional
  79       * @return string
  80       */
  81      public static function savePublicKey(BigInteger $p, BigInteger $q, BigInteger $g, BigInteger $y, array $options = [])
  82      {
  83          if ($q->getLength() != 160) {
  84              throw new \InvalidArgumentException('SSH only supports keys with an N (length of Group Order q) of 160');
  85          }
  86  
  87          // from <http://tools.ietf.org/html/rfc4253#page-15>:
  88          // string    "ssh-dss"
  89          // mpint     p
  90          // mpint     q
  91          // mpint     g
  92          // mpint     y
  93          $DSAPublicKey = Strings::packSSH2('siiii', 'ssh-dss', $p, $q, $g, $y);
  94  
  95          if (isset($options['binary']) ? $options['binary'] : self::$binary) {
  96              return $DSAPublicKey;
  97          }
  98  
  99          $comment = isset($options['comment']) ? $options['comment'] : self::$comment;
 100          $DSAPublicKey = 'ssh-dss ' . base64_encode($DSAPublicKey) . ' ' . $comment;
 101  
 102          return $DSAPublicKey;
 103      }
 104  
 105      /**
 106       * Convert a private key to the appropriate format.
 107       *
 108       * @access public
 109       * @param \phpseclib3\Math\BigInteger $p
 110       * @param \phpseclib3\Math\BigInteger $q
 111       * @param \phpseclib3\Math\BigInteger $g
 112       * @param \phpseclib3\Math\BigInteger $y
 113       * @param \phpseclib3\Math\BigInteger $x
 114       * @param string $password optional
 115       * @param array $options optional
 116       * @return string
 117       */
 118      public static function savePrivateKey(BigInteger $p, BigInteger $q, BigInteger $g, BigInteger $y, BigInteger $x, $password = '', array $options = [])
 119      {
 120          $publicKey = self::savePublicKey($p, $q, $g, $y, ['binary' => true]);
 121          $privateKey = Strings::packSSH2('si5', 'ssh-dss', $p, $q, $g, $y, $x);
 122  
 123          return self::wrapPrivateKey($publicKey, $privateKey, $password, $options);
 124      }
 125  }