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     throw new \moodle_exception('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 $encoder = new \PhpXmlRpc\Encoder();
  70 $orequest = $encoder->decodeXML($xmlrpcrequest); // First, to internal.
  71 $method = $orequest->method(); // We just need the method.
  72 mnet_debug("incoming mnet request $method");
  73
  74 // One of three conditions need to be met before we continue processing this request:
  75 // 1. Request is properly encrypted and signed
  76 // 2. Request is for a keyswap (we don't mind enencrypted or unsigned requests for a public key)
  77 // 3. Request is properly signed and we're happy with it being unencrypted
  78 if ((($remoteclient->request_was_encrypted == true) && ($remoteclient->signatureok == true))
  79     || (($method == 'system.keyswap') || ($method == 'system/keyswap'))
  80     || (($remoteclient->signatureok == true) && ($remoteclient->plaintext_is_ok() == true))) {
  81     try {
  82         // main dispatch call.  will echo the response directly
  83         mnet_server_dispatch($xmlrpcrequest);
  84         mnet_debug('exiting cleanly');
  85         exit;
  86     } catch (Exception $e) {
  87         mnet_debug('dispatch exception thrown: ' . $e->getMessage());
  88         exit(mnet_server_fault($e->getCode(), $e->getMessage(), $e->a));
  89     }
  90 }
  91 // if we get to here, something is wrong
  92 // so detect a few common cases and send appropriate errors
  93 if (($remoteclient->request_was_encrypted == false) && ($remoteclient->plaintext_is_ok() == false)) {
  94     mnet_debug('non encrypted request');
  95     exit(mnet_server_fault(7021, get_string('forbidden-transport', 'mnet')));
  96 }
  97
  98 if ($remoteclient->request_was_signed == false) {
  99     // Request was not signed
 100     mnet_debug('non signed request');
 101     exit(mnet_server_fault(711, get_string('verifysignature-error', 'mnet')));
 102 }
 103
 104 if ($remoteclient->signatureok == false) {
 105     // We were unable to verify the signature
 106     mnet_debug('non verified signature');
 107     exit(mnet_server_fault(710, get_string('verifysignature-invalid', 'mnet')));
 108 }
 109 mnet_debug('unknown error');
 110 exit(mnet_server_fault(7000, get_string('unknownerror', 'mnet')));