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