moodle/mnet/xmlrpc/server.php
2007-01-04 02:33:51 +00:00

670 lines
25 KiB
PHP

<?php
/**
* An XML-RPC server
*
* @author Donal McMullan donal@catalyst.net.nz
* @version 0.0.1
* @license http://www.gnu.org/copyleft/gpl.html GNU Public License
* @package mnet
*/
// Make certain that config.php doesn't display any errors, and that it doesn't
// override our do-not-display-errors setting:
ini_set('display_errors',0);
require_once(dirname(dirname(dirname(__FILE__))) . '/config.php');
ini_set('display_errors',0);
// Include MNET stuff:
require_once $CFG->dirroot.'/mnet/lib.php';
require_once $CFG->dirroot.'/mnet/remote_client.php';
// Content type for output is not html:
header('Content-type: text/xml');
if (!empty($CFG->mnet_rpcdebug)) {
trigger_error("HTTP_RAW_POST_DATA");
trigger_error($HTTP_RAW_POST_DATA);
}
// New global variable which ONLY gets set in this server page, so you know that
// if you've been called by a remote Moodle, this should be set:
$MNET_REMOTE_CLIENT = new mnet_remote_client();
// Peek at the message to see if it's an XML-ENC document. If it is, note that
// the client connection was encrypted, and strip the xml-encryption and
// xml-signature wrappers from the XML-RPC payload
if (strpos(substr($HTTP_RAW_POST_DATA, 0, 100), '<encryptedMessage>')) {
$MNET_REMOTE_CLIENT->was_encrypted();
// Extract the XML-RPC payload from the XML-ENC and XML-SIG wrappers.
$payload = mnet_server_strip_wrappers($HTTP_RAW_POST_DATA);
} else {
$params = xmlrpc_decode_request($HTTP_RAW_POST_DATA, $method);
if ($method == 'system.keyswap' ||
$method == 'system/keyswap') {
// OK
} elseif ($MNET_REMOTE_CLIENT->plaintext_is_ok() == false) {
exit(mnet_server_fault(7021, 'forbidden-transport'));
}
// Looks like plaintext is ok. It is assumed that a plaintext call:
// 1. Came from a trusted host on your local network
// 2. Is *not* from a Moodle - otherwise why skip encryption/signing?
// 3. Is free to execute ANY function in Moodle
// 4. Cannot execute any methods (as it can't instantiate a class first)
// To execute a method, you'll need to create a wrapper function that first
// instantiates the class, and then calls the method.
$payload = $HTTP_RAW_POST_DATA;
}
if (!empty($CFG->mnet_rpcdebug)) {
trigger_error("XMLRPC Payload");
trigger_error(print_r($payload,1));
}
// Parse and action the XML-RPC payload
$response = mnet_server_dispatch($payload);
/**
* Strip the encryption (XML-ENC) and signature (XML-SIG) wrappers and return the XML-RPC payload
*
* IF COMMUNICATION TAKES PLACE OVER UNENCRYPTED HTTP:
* The payload will have been encrypted with a symmetric key. This key will
* itself have been encrypted using your public key. The key is decrypted using
* your private key, and then used to decrypt the XML payload.
*
* IF COMMUNICATION TAKES PLACE OVER UNENCRYPTED HTTP *OR* ENCRYPTED HTTPS:
* In either case, there will be an XML wrapper which contains your XML-RPC doc
* as an object element, a signature for that doc, and various standards-
* compliant info to aid in verifying the signature.
*
* This function parses the encryption wrapper, decrypts the contents, parses
* the signature wrapper, and if the signature matches the payload, it returns
* the payload, which should be an XML-RPC request.
* If there is an error, or the signatures don't match, it echoes an XML-RPC
* error and exits.
*
* See the W3C's {@link http://www.w3.org/TR/xmlenc-core/ XML Encryption Syntax and Processing}
* and {@link http://www.w3.org/TR/2001/PR-xmldsig-core-20010820/ XML-Signature Syntax and Processing}
* guidelines for more detail on the XML.
*
* -----XML-Envelope---------------------------------
* | |
* | Encrypted-Symmetric-key---------------- |
* | |_____________________________________| |
* | |
* | Encrypted data------------------------- |
* | | | |
* | | -XML-Envelope------------------ | |
* | | | | | |
* | | | --Signature------------- | | |
* | | | |______________________| | | |
* | | | | | |
* | | | --Signed-Payload-------- | | |
* | | | | | | | |
* | | | | XML-RPC Request | | | |
* | | | |______________________| | | |
* | | | | | |
* | | |_____________________________| | |
* | |_____________________________________| |
* | |
* |________________________________________________|
*
* @uses $db
* @param string $HTTP_RAW_POST_DATA The XML that the client sent
* @return string The XMLRPC payload.
*/
function mnet_server_strip_wrappers($HTTP_RAW_POST_DATA) {
global $MNET, $MNET_REMOTE_CLIENT;
if (isset($_SERVER)) {
$crypt_parser = new mnet_encxml_parser();
$crypt_parser->parse($HTTP_RAW_POST_DATA);
if ($crypt_parser->payload_encrypted) {
$key = array_pop($crypt_parser->cipher);
$data = array_pop($crypt_parser->cipher);
$crypt_parser->free_resource();
// Initialize payload var
$payload = '';
// &$payload
$isOpen = openssl_open(base64_decode($data), $payload, base64_decode($key), $MNET->get_private_key());
if (!$isOpen) {
exit(mnet_server_fault(7023, 'encryption-invalid'));
}
if (strpos(substr($payload, 0, 100), '<signedMessage>')) {
$MNET_REMOTE_CLIENT->was_signed();
$sig_parser = new mnet_encxml_parser();
$sig_parser->parse($payload);
} else {
exit(mnet_server_fault(7022, 'verifysignature-error'));
}
} else {
exit(mnet_server_fault(7024, 'payload-not-encrypted'));
}
unset($payload);
$host_record_exists = $MNET_REMOTE_CLIENT->set_wwwroot($sig_parser->remote_wwwroot);
if (false == $host_record_exists) {
exit(mnet_server_fault(7020, 'wrong-wwwroot', $sig_parser->remote_wwwroot));
} elseif (isset($_SERVER['REMOTE_ADDR']) && $_SERVER['REMOTE_ADDR'] != $MNET_REMOTE_CLIENT->ip_address) {
exit(mnet_server_fault(7017, 'wrong-ip'));
}
/**
* Get the certificate (i.e. public key) from the remote server.
*/
$certificate = $MNET_REMOTE_CLIENT->public_key;
if ($certificate == false) {
exit(mnet_server_fault(709, 'nosuchpublickey'));
}
$payload = base64_decode($sig_parser->data_object);
// Does the signature match the data and the public cert?
$signature_verified = openssl_verify($payload, base64_decode($sig_parser->signature), $certificate);
if ($signature_verified == 1) {
// Parse the XML
} elseif ($signature_verified == 0) {
exit(mnet_server_fault(710, 'verifysignature-invalid'));
} else {
exit(mnet_server_fault(711, 'verifysignature-error'));
}
$sig_parser->free_resource();
return $payload;
} else {
exit(mnet_server_fault(712, "phperror"));
}
}
/**
* Return the proper XML-RPC content to report an error.
*
* @param int $code The ID code of the error message
* @return string $text The text of the error message
*/
function mnet_server_fault($code, $text, $param = null) {
if (!is_numeric($code)) {
$code = 0;
}
$code = intval($code);
$text = get_string($text, 'mnet', $param);
// Replace illegal XML chars - is this already in a lib somewhere?
$text = str_replace(array('<','>','&','"',"'"), array('&lt;','&gt;','&amp;','&quot;','&apos;'), $text);
$return = mnet_server_prepare_response('<?xml version="1.0"?>
<methodResponse>
<fault>
<value>
<struct>
<member>
<name>faultCode</name>
<value><int>'.$code.'</int></value>
</member>
<member>
<name>faultString</name>
<value><string>'.$text.'</string></value>
</member>
</struct>
</value>
</fault>
</methodResponse>');
return $return;
}
/**
* Dummy function for the XML-RPC dispatcher - use to call a method on an object
* or to call a function
*
* Translate XML-RPC's strange function call syntax into a more straightforward
* PHP-friendly alternative. This dummy function will be called by the
* dispatcher, and can be used to call a method on an object, or just a function
*
* The methodName argument (eg. mnet/testlib/mnet_concatenate_strings)
* is ignored.
*
* @param string $methodname We discard this - see 'functionname'
* @param array $argsarray Each element is an argument to the real
* function
* @param string $functionname The name of the PHP function you want to call
* @return mixed The return value will be that of the real
* function, whateber it may be.
*/
function mnet_server_dummy_method($methodname, $argsarray, $functionname) {
global $MNET_REMOTE_CLIENT;
if ($MNET_REMOTE_CLIENT->object_to_call == false) {
return @call_user_func_array($functionname, $argsarray);
} else {
return @call_user_method_array($functionname, $MNET_REMOTE_CLIENT->object_to_call, $argsarray);
}
}
/**
* Package a response in any required envelope, and return it to the client
*
* @param string $response The XMLRPC response string
* @return string The encoded response string
*/
function mnet_server_prepare_response($response) {
global $MNET_REMOTE_CLIENT;
if ($MNET_REMOTE_CLIENT->request_was_signed) {
$response = mnet_sign_message($response);
}
if ($MNET_REMOTE_CLIENT->request_was_encrypted) {
$response = mnet_encrypt_message($response, $MNET_REMOTE_CLIENT->public_key);
}
return $response;
}
/**
* If security checks are passed, dispatch the request to the function/method
*
* The config variable 'mnet_dispatcher_mode' can be:
* strict: Only execute functions that are in specific files
* off: The default - don't execute anything
*
* @param string $payload The XML-RPC request
* @return No return val - just echo the response
*/
function mnet_server_dispatch($payload) {
global $CFG, $MNET_REMOTE_CLIENT;
// xmlrpc_decode_request returns an array of parameters, and the $method
// variable (which is passed by reference) is instantiated with the value from
// the methodName tag in the xml payload
// xmlrpc_decode_request($xml, &$method)
$params = xmlrpc_decode_request($payload, $method);
// $method is something like: "mod/forum/lib/forum_add_instance"
// $params is an array of parameters. A parameter might itself be an array.
// Whitelist characters that are permitted in a method name
// The method name must not begin with a / - avoid absolute paths
// A dot character . is only allowed in the filename, i.e. something.php
if (0 == preg_match("@^[A-Za-z0-9]+/[A-Za-z0-9/_-]+(\.php/)?[A-Za-z0-9_-]+$@",$method)) {
exit(mnet_server_fault(713, 'nosuchfunction'));
}
$callstack = explode('/', $method);
// callstack will look like array('mod', 'forum', 'lib', 'forum_add_instance');
/**
* What has the site administrator chosen as his dispatcher setting?
* strict: Only execute functions that are in specific files
* off: The default - don't execute anything
*/
////////////////////////////////////// OFF
if (!isset($CFG->mnet_dispatcher_mode) ) {
set_config('mnet_dispatcher_mode', 'off');
exit(mnet_server_fault(704, 'nosuchservice'));
} elseif ('off' == $CFG->mnet_dispatcher_mode) {
exit(mnet_server_fault(704, 'nosuchservice'));
////////////////////////////////////// SYSTEM METHODS
} elseif ($callstack[0] == 'system') {
$functionname = $callstack[1];
$xmlrpcserver = xmlrpc_server_create();
// I'm adding the canonical xmlrpc references here, however we've
// already forbidden that the period (.) should be allowed in the call
// stack, so if someone tries to access our XMLRPC in the normal way,
// they'll already have received a RPC server fault message.
// Maybe we should allow an easement so that regular XMLRPC clients can
// call our system methods, and find out what we have to offer?
xmlrpc_server_register_method($xmlrpcserver, 'system.listMethods', 'mnet_system');
xmlrpc_server_register_method($xmlrpcserver, 'system/listMethods', 'mnet_system');
xmlrpc_server_register_method($xmlrpcserver, 'system.methodSignature', 'mnet_system');
xmlrpc_server_register_method($xmlrpcserver, 'system/methodSignature', 'mnet_system');
xmlrpc_server_register_method($xmlrpcserver, 'system.methodHelp', 'mnet_system');
xmlrpc_server_register_method($xmlrpcserver, 'system/methodHelp', 'mnet_system');
xmlrpc_server_register_method($xmlrpcserver, 'system.listServices', 'mnet_system');
xmlrpc_server_register_method($xmlrpcserver, 'system/listServices', 'mnet_system');
xmlrpc_server_register_method($xmlrpcserver, 'system.keyswap', 'mnet_keyswap');
xmlrpc_server_register_method($xmlrpcserver, 'system/keyswap', 'mnet_keyswap');
if ($method == 'system.listMethods' ||
$method == 'system/listMethods' ||
$method == 'system.methodSignature' ||
$method == 'system/methodSignature' ||
$method == 'system.methodHelp' ||
$method == 'system/methodHelp' ||
$method == 'system.listServices' ||
$method == 'system/listServices' ||
$method == 'system.keyswap' ||
$method == 'system/keyswap') {
$response = xmlrpc_server_call_method($xmlrpcserver, $payload, $MNET_REMOTE_CLIENT);
$response = mnet_server_prepare_response($response);
} else {
exit(mnet_server_fault(7018, 'nosuchfunction'));
}
xmlrpc_server_destroy($xmlrpcserver);
echo $response;
////////////////////////////////////// STRICT AUTH
} elseif ($callstack[0] == 'auth') {
// Break out the callstack into its elements
list($base, $plugin, $filename, $methodname) = $callstack;
// We refuse to include anything that is not auth.php
if ($filename == 'auth.php' && is_enabled_auth($plugin)) {
$authclass = 'auth_plugin_'.$plugin;
$includefile = '/auth/'.$plugin.'/auth.php';
$response = mnet_server_invoke_method($includefile, $methodname, $method, $payload, $authclass);
$response = mnet_server_prepare_response($response);
echo $response;
} else {
// Generate error response - unable to locate function
exit(mnet_server_fault(702, 'nosuchfunction'));
}
////////////////////////////////////// STRICT ENROL
} elseif ($callstack[0] == 'enrol') {
// Break out the callstack into its elements
list($base, $plugin, $filename, $methodname) = $callstack;
if ($filename == 'enrol.php' && is_enabled_enrol($plugin)) {
$enrolclass = 'enrolment_plugin_'.$plugin;
$includefile = '/enrol/'.$plugin.'/enrol.php';
$response = mnet_server_invoke_method($includefile, $methodname, $method, $payload, $enrolclass);
$response = mnet_server_prepare_response($response);
echo $response;
} else {
// Generate error response - unable to locate function
exit(mnet_server_fault(703, 'nosuchfunction'));
}
////////////////////////////////////// STRICT MOD/*
} elseif ($callstack[0] == 'mod' || 'promiscuous' == $CFG->mnet_dispatcher_mode) {
list($base, $module, $filename, $functionname) = $callstack;
////////////////////////////////////// STRICT MOD/*
if ($base == 'mod' && $filename == 'rpclib.php') {
$includefile = '/mod/'.$module.'/rpclib.php';
$response = mnet_server_invoke_method($includefile, $functionname, $method, $payload);
$response = mnet_server_prepare_response($response);
echo $response;
////////////////////////////////////// PROMISCUOUS
} elseif ('promiscuous' == $CFG->mnet_dispatcher_mode && $MNET_REMOTE_CLIENT->plaintext_is_ok()) {
$functionname = array_pop($callstack);
$filename = array_pop($callstack);
if ($MNET_REMOTE_CLIENT->plaintext_is_ok()) {
// The call stack holds the path to any include file
$includefile = $CFG->dirroot.'/'.implode('/',$callstack).'/'.$filename.'.php';
$response = mnet_server_invoke_function($includefile, $functionname, $method, $payload);
echo $response;
}
} else {
// Generate error response - unable to locate function
exit(mnet_server_fault(7012, 'nosuchfunction'));
}
} else {
// Generate error response - unable to locate function
exit(mnet_server_fault(7012, 'nosuchfunction'));
}
}
/**
* Execute the system functions - mostly for introspection
*
* @param string $method XMLRPC method name, e.g. system.listMethods
* @param array $params Array of parameters from the XMLRPC request
* @param string $hostinfo Hostinfo object from the mnet_host table
* @return mixed Response data - any kind of PHP variable
*/
function mnet_system($method, $params, $hostinfo) {
global $CFG;
if (empty($hostinfo)) return array();
$id_list = $hostinfo->id;
if (!empty($CFG->mnet_all_hosts_id)) {
$id_list .= ', '.$CFG->mnet_all_hosts_id;
}
if ('system.listMethods' == $method || 'system/listMethods' == $method) {
if (count($params) == 0) {
$query = '
SELECT DISTINCT
rpc.function_name,
rpc.xmlrpc_path,
rpc.enabled,
rpc.help,
rpc.profile
FROM
'.$CFG->prefix.'mnet_host2service h2s,
'.$CFG->prefix.'mnet_service2rpc s2r,
'.$CFG->prefix.'mnet_rpc rpc
WHERE
s2r.rpcid = rpc.id AND
h2s.serviceid = s2r.serviceid AND
h2s.hostid in ('.$id_list .')
ORDER BY
rpc.xmlrpc_path ASC';
} else {
$query = '
SELECT DISTINCT
rpc.function_name,
rpc.xmlrpc_path,
rpc.enabled,
rpc.help,
rpc.profile
FROM
'.$CFG->prefix.'mnet_host2service h2s,
'.$CFG->prefix.'mnet_service2rpc s2r,
'.$CFG->prefix.'mnet_service svc,
'.$CFG->prefix.'mnet_rpc rpc
WHERE
s2r.rpcid = rpc.id AND
h2s.serviceid = s2r.serviceid AND
h2s.hostid in ('.$id_list .') AND
svc.id = h2s.serviceid AND
svc.name = \''.$params[0].'\'
ORDER BY
rpc.xmlrpc_path ASC';
}
$resultset = array_values(get_records_sql($query));
$methods = array();
foreach($resultset as $result) {
$methods[] = $result->xmlrpc_path;
}
return $methods;
} elseif ('system.methodSignature' == $method || 'system/methodSignature' == $method) {
$query = '
SELECT DISTINCT
rpc.function_name,
rpc.xmlrpc_path,
rpc.enabled,
rpc.help,
rpc.profile
FROM
'.$CFG->prefix.'mnet_host2service h2s,
'.$CFG->prefix.'mnet_service2rpc s2r,
'.$CFG->prefix.'mnet_rpc rpc
WHERE
rpc.xmlrpc_path = \''.$params[0].'\' AND
s2r.rpcid = rpc.id AND
h2s.serviceid = s2r.serviceid AND
h2s.hostid in ('.$id_list .')';
$result = get_records_sql($query);
$methodsigs = array();
if (is_array($result)) {
foreach($result as $method) {
$methodsigs[] = unserialize($method->profile);
}
}
return $methodsigs;
} elseif ('system.methodHelp' == $method || 'system/methodHelp' == $method) {
$query = '
SELECT DISTINCT
rpc.function_name,
rpc.xmlrpc_path,
rpc.enabled,
rpc.help,
rpc.profile
FROM
'.$CFG->prefix.'mnet_host2service h2s,
'.$CFG->prefix.'mnet_service2rpc s2r,
'.$CFG->prefix.'mnet_rpc rpc
WHERE
rpc.xmlrpc_path = \''.$params[0].'\' AND
s2r.rpcid = rpc.id AND
h2s.serviceid = s2r.serviceid AND
h2s.hostid in ('.$id_list .')';
$result = get_record_sql($query);
if (is_object($result)) {
return $result->help;
}
} elseif ('system.listServices' == $method || 'system/listServices' == $method) {
$query = '
SELECT DISTINCT
s.id,
s.name,
s.apiversion,
h2s.publish,
h2s.subscribe
FROM
'.$CFG->prefix.'mnet_host2service h2s,
'.$CFG->prefix.'mnet_service s
WHERE
h2s.serviceid = s.id AND
h2s.hostid in ('.$id_list .')
ORDER BY
s.name ASC';
$result = get_records_sql($query);
$services = array();
if (is_array($result)) {
foreach($result as $service) {
$services[] = array('name' => $service->name,
'apiversion' => $service->apiversion,
'publish' => $service->publish,
'subscribe' => $service->subscribe);
}
}
return $services;
}
exit(mnet_server_fault(7019, 'nosuchfunction'));
}
/**
* Initialize the object (if necessary), execute the method or function, and
* return the response
*
* @param string $includefile The file that contains the object definition
* @param string $methodname The name of the method to execute
* @param string $method The full path to the method
* @param string $payload The XML-RPC request payload
* @param string $class The name of the class to instantiate (or false)
* @return string The XML-RPC response
*/
function mnet_server_invoke_method($includefile, $methodname, $method, $payload, $class=false) {
$permission = mnet_permit_rpc_call($includefile, $methodname, $class);
if (RPC_NOSUCHFILE == $permission) {
// Generate error response - unable to locate function
exit(mnet_server_fault(705, 'nosuchfile', $includefile));
}
if (RPC_NOSUCHFUNCTION == $permission) {
// Generate error response - unable to locate function
exit(mnet_server_fault(706, 'nosuchfunction'));
}
if (RPC_FORBIDDENFUNCTION == $permission) {
// Generate error response - unable to locate function
exit(mnet_server_fault(707, 'forbidden-function'));
}
if (RPC_NOSUCHCLASS == $permission) {
// Generate error response - unable to locate function
exit(mnet_server_fault(7013, 'nosuchfunction'));
}
if (RPC_NOSUCHMETHOD == $permission) {
// Generate error response - unable to locate function
exit(mnet_server_fault(7014, 'nosuchmethod'));
}
if (RPC_NOSUCHFUNCTION == $permission) {
// Generate error response - unable to locate function
exit(mnet_server_fault(7014, 'nosuchmethod'));
}
if (RPC_FORBIDDENMETHOD == $permission) {
// Generate error response - unable to locate function
exit(mnet_server_fault(7015, 'nosuchfunction'));
}
if (0 < $permission) {
// Generate error response - unable to locate function
exit(mnet_server_fault(7019, 'unknownerror'));
}
if (RPC_OK == $permission) {
$xmlrpcserver = xmlrpc_server_create();
$bool = xmlrpc_server_register_method($xmlrpcserver, $method, 'mnet_server_dummy_method');
$response = xmlrpc_server_call_method($xmlrpcserver, $payload, $methodname);
$bool = xmlrpc_server_destroy($xmlrpcserver);
return $response;
}
}
function mnet_keyswap($function, $params) {
global $CFG;
$return = array();
if (!empty($CFG->mnet_register_allhosts)) {
$mnet_peer = new mnet_peer();
$keyok = $mnet_peer->bootstrap($params[0]);
if ($keyok) {
$mnet_peer->commit();
}
}
$keypair = mnet_get_keypair();
return $keypair['certificate'];
}
?>