[Sommaire] [Imprimer]

   1  <?php
   2  /**
   3   * The Net_IMSP_Auth_cram_md5 class for IMSP authentication.
   4   *
   5   * Required parameters:<pre>
   6   *   'username'  Username to logon to IMSP server as.
   7   *   'password'  Password for current user.
   8   *   'server'    The hostname of the IMSP server.
   9   *   'port'      The port of the IMSP server.</pre>
  10   *
  11   * $Horde: framework/Net_IMSP/IMSP/Auth/cram_md5.php,v 1.6.10.9 2006/01/01 21:28:28 jan Exp $
  12   *
  13   * Copyright 2003-2006 Michael Rubinsky <mrubinsk@horde.org>
  14   *
  15   * See the enclosed file COPYING for license information (LGPL). If you
  16   * did not receive this file, see http://www.fsf.org/copyleft/lgpl.html.
  17   *
  18   * @author  Michael Rubinsky <mrubinsk@horde.org>
  19   * @package Net_IMSP
  20   */
  21  class Net_IMSP_Auth_cram_md5 extends Net_IMSP_Auth {
  22  
  23      /**
  24       * Private authentication function.  Provides actual
  25       * authentication code.
  26       *
  27       * @access private
  28       * @param  mixed $params Hash of IMSP parameters.
  29       *
  30       * @return mixed Net_IMSP object connected to server if successful,
  31       *               PEAR_Error on failure.
  32       */
  33      function &_authenticate($params)
  34      {
  35          $imsp = &Net_IMSP::singleton('none', $params);
  36          $result = $imsp->init();
  37          if (is_a($result, 'PEAR_Error')) {
  38              return $result;
  39          }
  40  
  41          $userId = $params['username'];
  42          $credentials = $params['password'];
  43          $result = $imsp->imspSend('AUTHENTICATE CRAM-MD5');
  44          if (is_a($result, 'PEAR_Error')) {
  45              return $result;
  46          }
  47  
  48          /* Get response and decode it. Note that we remove the 1st 2
  49           * characters from the response to get rid of the '+'
  50           * continuation character and the space that is sent as part
  51           * of the CRAM-MD5 response (at least on cyrus-imspd). */
  52          $server_response = $imsp->imspReceive();
  53          if (is_a($server_response, 'PEAR_Error')) {
  54              return $server_response;
  55          }
  56  
  57          $server_response = base64_decode(trim(substr($server_response, 2)));
  58  
  59          /* Build and base64 encode the response to the challange. */
  60          $response_to_send = $userId . ' ' . $this->_hmac($credentials, $server_response);
  61          $command_string = base64_encode($response_to_send);
  62  
  63          /* Send the response. */
  64          $result = $imsp->imspSend($command_string, false);
  65          if (is_a($result, 'PEAR_Error')) {
  66              return $result;
  67          }
  68  
  69          $result = $imsp->imspReceive();
  70          if (is_a($result, 'PEAR_Error')) {
  71              return $result;
  72          }
  73  
  74          if ($result != 'OK') {
  75              return $imsp->imspError('Login to IMSP host failed.', __FILE__, __LINE__);
  76          } else {
  77              return $imsp;
  78          }
  79      }
  80  
  81      /**
  82       * RFC 2104 HMAC implementation. Eliminates the reliance on mhash.
  83       *
  84       * @access private
  85       * @param  string  $key    The HMAC key.
  86       * @param  string  $data   The data to hash with the key.
  87       *
  88       * @return string  The MD5 HMAC.
  89       */
  90      function _hmac($key, $data)
  91      {
  92          /* Byte length for md5. */
  93          $b = 64;
  94  
  95          if (strlen($key) > $b) {
  96              $key = pack('H*', md5($key));
  97          }
  98  
  99          $key = str_pad($key, $b, chr(0x00));
 100          $ipad = str_pad('', $b, chr(0x36));
 101          $opad = str_pad('', $b, chr(0x5c));
 102          $k_ipad = $key ^ $ipad;
 103          $k_opad = $key ^ $opad;
 104          return md5($k_opad . pack('H*', md5($k_ipad . $data)));
 105      }
 106  
 107      /**
 108       * Force a logout command to the imsp stream.
 109       *
 110       */
 111      function logout()
 112      {
 113          $this->_imsp->logout();
 114      }
 115  
 116      /**
 117       * Return the driver type
 118       *
 119       * @return string the type of this IMSP_Auth driver
 120       */
 121       function getDriverType()
 122       {
 123           return 'cram_md5';
 124       }
 125  
 126  }