mnet/xmlrpc/server.php

   1 <?php
   2 /**
   3  * An XML-RPC server
   4  *
   5  * @author  Donal McMullan  donal@catalyst.net.nz
   6  * @version 0.0.1
   7  * @license http://www.gnu.org/copyleft/gpl.html GNU Public License
   8  * @package mnet
   9  */
  10
  11 // Make certain that config.php doesn't display any errors, and that it doesn't
  12 // override our do-not-display-errors setting:
  13 // disable moodle specific debug messages and any errors in output
  14 define('NO_DEBUG_DISPLAY', true);
  15 // cookies are not used, makes sure there is empty global $USER
  16 define('NO_MOODLE_COOKIES', true);
  17
  18 define('MNET_SERVER', true);
  19
  20 require(__DIR__.'/../../config.php');
  21
  22 $mnet = get_mnet_environment();
  23 // Include MNET stuff:
  24 require_once $CFG->dirroot.'/mnet/lib.php';
  25 require_once $CFG->dirroot.'/mnet/remote_client.php';
  26 require_once $CFG->dirroot.'/mnet/xmlrpc/serverlib.php';
  27
  28
  29 if ($CFG->mnet_dispatcher_mode === 'off') {
  30     print_error('mnetdisabled', 'mnet');
  31 }
  32
  33 // Content type for output is not html:
  34 header('Content-type: text/xml; charset=utf-8');
  35
  36 $rawpostdata = file_get_contents("php://input");
  37 mnet_debug("RAW POST DATA", 2);
  38 mnet_debug($rawpostdata, 2);
  39
  40 if (!isset($_SERVER)) {
  41     exit(mnet_server_fault(712, get_string('phperror', 'mnet')));
  42 }
  43
  44
  45 // New global variable which ONLY gets set in this server page, so you know that
  46 // if you've been called by a remote Moodle, this should be set:
  47 $remoteclient = new mnet_remote_client();
  48 set_mnet_remote_client($remoteclient);
  49
  50 try {
  51     $plaintextmessage = mnet_server_strip_encryption($rawpostdata);
  52     $xmlrpcrequest = mnet_server_strip_signature($plaintextmessage);
  53 } catch (Exception $e) {
  54     mnet_debug('encryption strip exception thrown: ' . $e->getMessage());
  55     exit(mnet_server_fault($e->getCode(), $e->getMessage(), $e->a));
  56 }
  57
  58 mnet_debug('XMLRPC Payload', 2);
  59 mnet_debug($xmlrpcrequest, 2);
  60
  61 if($remoteclient->pushkey == true) {
  62     // The peer used one of our older public keys, we will return a
  63     // signed/encrypted error message containing our new public key
  64     // Sign message with our old key, and encrypt to the peer's private key.
  65     mnet_debug('sending back new key');
  66     exit(mnet_server_fault_xml(7025, $mnet->public_key, $remoteclient->useprivatekey));
  67 }
  68 // Have a peek at what the request would be if we were to process it
  69 $params = xmlrpc_decode_request($xmlrpcrequest, $method);
  70 mnet_debug("incoming mnet request $method");
  71
  72 // One of three conditions need to be met before we continue processing this request:
  73 // 1. Request is properly encrypted and signed
  74 // 2. Request is for a keyswap (we don't mind enencrypted or unsigned requests for a public key)
  75 // 3. Request is properly signed and we're happy with it being unencrypted
  76 if ((($remoteclient->request_was_encrypted == true) && ($remoteclient->signatureok == true))
  77     || (($method == 'system.keyswap') || ($method == 'system/keyswap'))
  78     || (($remoteclient->signatureok == true) && ($remoteclient->plaintext_is_ok() == true))) {
  79     try {
  80         // main dispatch call.  will echo the response directly
  81         mnet_server_dispatch($xmlrpcrequest);
  82         mnet_debug('exiting cleanly');
  83         exit;
  84     } catch (Exception $e) {
  85         mnet_debug('dispatch exception thrown: ' . $e->getMessage());
  86         exit(mnet_server_fault($e->getCode(), $e->getMessage(), $e->a));
  87     }
  88 }
  89 // if we get to here, something is wrong
  90 // so detect a few common cases and send appropriate errors
  91 if (($remoteclient->request_was_encrypted == false) && ($remoteclient->plaintext_is_ok() == false)) {
  92     mnet_debug('non encrypted request');
  93     exit(mnet_server_fault(7021, get_string('forbidden-transport', 'mnet')));
  94 }
  95
  96 if ($remoteclient->request_was_signed == false) {
  97     // Request was not signed
  98     mnet_debug('non signed request');
  99     exit(mnet_server_fault(711, get_string('verifysignature-error', 'mnet')));
 100 }
 101
 102 if ($remoteclient->signatureok == false) {
 103     // We were unable to verify the signature
 104     mnet_debug('non verified signature');
 105     exit(mnet_server_fault(710, get_string('verifysignature-invalid', 'mnet')));
 106 }
 107 mnet_debug('unknown error');
 108 exit(mnet_server_fault(7000, get_string('unknownerror', 'mnet')));