mnet/lib.php

   1 <?php
   2 /**
   3  * Library functions for mnet
   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 require_once $CFG->dirroot.'/mnet/xmlrpc/xmlparser.php';
  11 require_once $CFG->dirroot.'/mnet/peer.php';
  12 require_once $CFG->dirroot.'/mnet/environment.php';
  13
  14 /// CONSTANTS ///////////////////////////////////////////////////////////
  15
  16 define('RPC_OK',                0);
  17 define('RPC_NOSUCHFILE',        1);
  18 define('RPC_NOSUCHCLASS',       2);
  19 define('RPC_NOSUCHFUNCTION',    3);
  20 define('RPC_FORBIDDENFUNCTION', 4);
  21 define('RPC_NOSUCHMETHOD',      5);
  22 define('RPC_FORBIDDENMETHOD',   6);
  23
  24 /**
  25  * Strip extraneous detail from a URL or URI and return the hostname
  26  *
  27  * @param  string  $uri  The URI of a file on the remote computer, optionally
  28  *                       including its http:// prefix like
  29  *                       http://www.example.com/index.html
  30  * @return string        Just the hostname
  31  */
  32 function mnet_get_hostname_from_uri($uri = null) {
  33     $count = preg_match("@^(?:http[s]?://)?([A-Z0-9\-\.]+).*@i", $uri, $matches);
  34     if ($count > 0) return $matches[1];
  35     return false;
  36 }
  37
  38 /**
  39  * Get the remote machine's SSL Cert
  40  *
  41  * @param  string  $uri     The URI of a file on the remote computer, including
  42  *                          its http:// or https:// prefix
  43  * @return string           A PEM formatted SSL Certificate.
  44  */
  45 function mnet_get_public_key($uri, $application=null) {
  46     global $CFG, $DB;
  47     $mnet = get_mnet_environment();
  48     // The key may be cached in the mnet_set_public_key function...
  49     // check this first
  50     $key = mnet_set_public_key($uri);
  51     if ($key != false) {
  52         return $key;
  53     }
  54
  55     if (empty($application)) {
  56         $application = $DB->get_record('mnet_application', array('name'=>'moodle'));
  57     }
  58
  59     $rq = xmlrpc_encode_request('system/keyswap', array($CFG->wwwroot, $mnet->public_key, $application->name), array(
  60         'encoding' => 'utf-8',
  61         'escaping' => 'markup',
  62     ));
  63     $ch = curl_init($uri . $application->xmlrpc_server_url);
  64
  65     curl_setopt($ch, CURLOPT_TIMEOUT, 60);
  66     curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
  67     curl_setopt($ch, CURLOPT_POST, true);
  68     curl_setopt($ch, CURLOPT_USERAGENT, 'Moodle');
  69     curl_setopt($ch, CURLOPT_POSTFIELDS, $rq);
  70     curl_setopt($ch, CURLOPT_HTTPHEADER, array("Content-Type: text/xml charset=UTF-8"));
  71     curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, false);
  72     curl_setopt($ch, CURLOPT_SSL_VERIFYHOST, 0);
  73
  74     // check for proxy
  75     if (!empty($CFG->proxyhost) and !is_proxybypass($uri)) {
  76         // SOCKS supported in PHP5 only
  77         if (!empty($CFG->proxytype) and ($CFG->proxytype == 'SOCKS5')) {
  78             if (defined('CURLPROXY_SOCKS5')) {
  79                 curl_setopt($ch, CURLOPT_PROXYTYPE, CURLPROXY_SOCKS5);
  80             } else {
  81                 curl_close($ch);
  82                 print_error( 'socksnotsupported','mnet' );
  83             }
  84         }
  85
  86         curl_setopt($ch, CURLOPT_HTTPPROXYTUNNEL, false);
  87
  88         if (empty($CFG->proxyport)) {
  89             curl_setopt($ch, CURLOPT_PROXY, $CFG->proxyhost);
  90         } else {
  91             curl_setopt($ch, CURLOPT_PROXY, $CFG->proxyhost.':'.$CFG->proxyport);
  92         }
  93
  94         if (!empty($CFG->proxyuser) and !empty($CFG->proxypassword)) {
  95             curl_setopt($ch, CURLOPT_PROXYUSERPWD, $CFG->proxyuser.':'.$CFG->proxypassword);
  96             if (defined('CURLOPT_PROXYAUTH')) {
  97                 // any proxy authentication if PHP 5.1
  98                 curl_setopt($ch, CURLOPT_PROXYAUTH, CURLAUTH_BASIC | CURLAUTH_NTLM);
  99             }
 100         }
 101     }
 102
 103     $res = xmlrpc_decode(curl_exec($ch));
 104
 105     // check for curl errors
 106     $curlerrno = curl_errno($ch);
 107     if ($curlerrno!=0) {
 108         debugging("Request for $uri failed with curl error $curlerrno");
 109     }
 110
 111     // check HTTP error code
 112     $info =  curl_getinfo($ch);
 113     if (!empty($info['http_code']) and ($info['http_code'] != 200)) {
 114         debugging("Request for $uri failed with HTTP code ".$info['http_code']);
 115     }
 116
 117     curl_close($ch);
 118
 119     if (!is_array($res)) { // ! error
 120         $public_certificate = $res;
 121         $credentials=array();
 122         if (strlen(trim($public_certificate))) {
 123             $credentials = openssl_x509_parse($public_certificate);
 124             $host = $credentials['subject']['CN'];
 125             if (array_key_exists( 'subjectAltName', $credentials['subject'])) {
 126                 $host = $credentials['subject']['subjectAltName'];
 127             }
 128             if (strpos($uri, $host) !== false) {
 129                 mnet_set_public_key($uri, $public_certificate);
 130                 return $public_certificate;
 131             }
 132             else {
 133                 debugging("Request for $uri returned public key for different URI - $host");
 134             }
 135         }
 136         else {
 137             debugging("Request for $uri returned empty response");
 138         }
 139     }
 140     else {
 141         debugging( "Request for $uri returned unexpected result");
 142     }
 143     return false;
 144 }
 145
 146 /**
 147  * Store a URI's public key in a static variable, or retrieve the key for a URI
 148  *
 149  * @param  string  $uri  The URI of a file on the remote computer, including its
 150  *                       https:// prefix
 151  * @param  mixed   $key  A public key to store in the array OR null. If the key
 152  *                       is null, the function will return the previously stored
 153  *                       key for the supplied URI, should it exist.
 154  * @return mixed         A public key OR true/false.
 155  */
 156 function mnet_set_public_key($uri, $key = null) {
 157     static $keyarray = array();
 158     if (isset($keyarray[$uri]) && empty($key)) {
 159         return $keyarray[$uri];
 160     } elseif (!empty($key)) {
 161         $keyarray[$uri] = $key;
 162         return true;
 163     }
 164     return false;
 165 }
 166
 167 /**
 168  * Sign a message and return it in an XML-Signature document
 169  *
 170  * This function can sign any content, but it was written to provide a system of
 171  * signing XML-RPC request and response messages. The message will be base64
 172  * encoded, so it does not need to be text.
 173  *
 174  * We compute the SHA1 digest of the message.
 175  * We compute a signature on that digest with our private key.
 176  * We link to the public key that can be used to verify our signature.
 177  * We base64 the message data.
 178  * We identify our wwwroot - this must match our certificate's CN
 179  *
 180  * The XML-RPC document will be parceled inside an XML-SIG document, which holds
 181  * the base64_encoded XML as an object, the SHA1 digest of that document, and a
 182  * signature of that document using the local private key. This signature will
 183  * uniquely identify the RPC document as having come from this server.
 184  *
 185  * See the {@Link http://www.w3.org/TR/xmldsig-core/ XML-DSig spec} at the W3c
 186  * site
 187  *
 188  * @param  string   $message              The data you want to sign
 189  * @param  resource $privatekey           The private key to sign the response with
 190  * @return string                         An XML-DSig document
 191  */
 192 function mnet_sign_message($message, $privatekey = null) {
 193     global $CFG;
 194     $digest = sha1($message);
 195
 196     $mnet = get_mnet_environment();
 197     // If the user hasn't supplied a private key (for example, one of our older,
 198     //  expired private keys, we get the current default private key and use that.
 199     if ($privatekey == null) {
 200         $privatekey = $mnet->get_private_key();
 201     }
 202
 203     // The '$sig' value below is returned by reference.
 204     // We initialize it first to stop my IDE from complaining.
 205     $sig  = '';
 206     $bool = openssl_sign($message, $sig, $privatekey); // TODO: On failure?
 207
 208     $message = '<?xml version="1.0" encoding="iso-8859-1"?>
 209     <signedMessage>
 210         <Signature Id="MoodleSignature" xmlns="http://www.w3.org/2000/09/xmldsig#">
 211             <SignedInfo>
 212                 <CanonicalizationMethod Algorithm="http://www.w3.org/TR/2001/REC-xml-c14n-20010315"/>
 213                 <SignatureMethod Algorithm="http://www.w3.org/2000/09/xmldsig#rsa-sha1"/>
 214                 <Reference URI="#XMLRPC-MSG">
 215                     <DigestMethod Algorithm="http://www.w3.org/2000/09/xmldsig#sha1"/>
 216                     <DigestValue>'.$digest.'</DigestValue>
 217                 </Reference>
 218             </SignedInfo>
 219             <SignatureValue>'.base64_encode($sig).'</SignatureValue>
 220             <KeyInfo>
 221                 <RetrievalMethod URI="'.$CFG->wwwroot.'/mnet/publickey.php"/>
 222             </KeyInfo>
 223         </Signature>
 224         <object ID="XMLRPC-MSG">'.base64_encode($message).'</object>
 225         <wwwroot>'.$mnet->wwwroot.'</wwwroot>
 226         <timestamp>'.time().'</timestamp>
 227     </signedMessage>';
 228     return $message;
 229 }
 230
 231 /**
 232  * Encrypt a message and return it in an XML-Encrypted document
 233  *
 234  * This function can encrypt any content, but it was written to provide a system
 235  * of encrypting XML-RPC request and response messages. The message will be
 236  * base64 encoded, so it does not need to be text - binary data should work.
 237  *
 238  * We compute the SHA1 digest of the message.
 239  * We compute a signature on that digest with our private key.
 240  * We link to the public key that can be used to verify our signature.
 241  * We base64 the message data.
 242  * We identify our wwwroot - this must match our certificate's CN
 243  *
 244  * The XML-RPC document will be parceled inside an XML-SIG document, which holds
 245  * the base64_encoded XML as an object, the SHA1 digest of that document, and a
 246  * signature of that document using the local private key. This signature will
 247  * uniquely identify the RPC document as having come from this server.
 248  *
 249  * See the {@Link http://www.w3.org/TR/xmlenc-core/ XML-ENC spec} at the W3c
 250  * site
 251  *
 252  * @param  string   $message              The data you want to sign
 253  * @param  string   $remote_certificate   Peer's certificate in PEM format
 254  * @return string                         An XML-ENC document
 255  */
 256 function mnet_encrypt_message($message, $remote_certificate) {
 257     $mnet = get_mnet_environment();
 258
 259     // Generate a key resource from the remote_certificate text string
 260     $publickey = openssl_get_publickey($remote_certificate);
 261
 262     if ($publickey === false) {
 263         // Remote certificate is faulty.
 264         return false;
 265     }
 266
 267     // Initialize vars
 268     $encryptedstring = '';
 269     $symmetric_keys = array();
 270
 271     //        passed by ref ->     &$encryptedstring &$symmetric_keys
 272     $bool = openssl_seal($message, $encryptedstring, $symmetric_keys, array($publickey), 'RC4');
 273     $message = $encryptedstring;
 274     $symmetrickey = array_pop($symmetric_keys);
 275
 276     $message = '<?xml version="1.0" encoding="iso-8859-1"?>
 277     <encryptedMessage>
 278         <EncryptedData Id="ED" xmlns="http://www.w3.org/2001/04/xmlenc#">
 279             <EncryptionMethod Algorithm="http://www.w3.org/2001/04/xmlenc#arcfour"/>
 280             <ds:KeyInfo xmlns:ds="http://www.w3.org/2000/09/xmldsig#">
 281                 <ds:RetrievalMethod URI="#EK" Type="http://www.w3.org/2001/04/xmlenc#EncryptedKey"/>
 282                 <ds:KeyName>XMLENC</ds:KeyName>
 283             </ds:KeyInfo>
 284             <CipherData>
 285                 <CipherValue>'.base64_encode($message).'</CipherValue>
 286             </CipherData>
 287         </EncryptedData>
 288         <EncryptedKey Id="EK" xmlns="http://www.w3.org/2001/04/xmlenc#">
 289             <EncryptionMethod Algorithm="http://www.w3.org/2001/04/xmlenc#rsa-1_5"/>
 290             <ds:KeyInfo xmlns:ds="http://www.w3.org/2000/09/xmldsig#">
 291                 <ds:KeyName>SSLKEY</ds:KeyName>
 292             </ds:KeyInfo>
 293             <CipherData>
 294                 <CipherValue>'.base64_encode($symmetrickey).'</CipherValue>
 295             </CipherData>
 296             <ReferenceList>
 297                 <DataReference URI="#ED"/>
 298             </ReferenceList>
 299             <CarriedKeyName>XMLENC</CarriedKeyName>
 300         </EncryptedKey>
 301         <wwwroot>'.$mnet->wwwroot.'</wwwroot>
 302     </encryptedMessage>';
 303     return $message;
 304 }
 305
 306 /**
 307  * Get your SSL keys from the database, or create them (if they don't exist yet)
 308  *
 309  * Get your SSL keys from the database, or (if they don't exist yet) call
 310  * mnet_generate_keypair to create them
 311  *
 312  * @param   string  $string     The text you want to sign
 313  * @return  string              The signature over that text
 314  */
 315 function mnet_get_keypair() {
 316     global $CFG, $DB;
 317     static $keypair = null;
 318     if (!is_null($keypair)) return $keypair;
 319     if ($result = get_config('mnet', 'openssl')) {
 320         list($keypair['certificate'], $keypair['keypair_PEM']) = explode('@@@@@@@@', $result);
 321         return $keypair;
 322     } else {
 323         $keypair = mnet_generate_keypair();
 324         return $keypair;
 325     }
 326 }
 327
 328 /**
 329  * Generate public/private keys and store in the config table
 330  *
 331  * Use the distinguished name provided to create a CSR, and then sign that CSR
 332  * with the same credentials. Store the keypair you create in the config table.
 333  * If a distinguished name is not provided, create one using the fullname of
 334  * 'the course with ID 1' as your organization name, and your hostname (as
 335  * detailed in $CFG->wwwroot).
 336  *
 337  * @param   array  $dn  The distinguished name of the server
 338  * @return  string      The signature over that text
 339  */
 340 function mnet_generate_keypair($dn = null, $days=28) {
 341     global $CFG, $USER, $DB;
 342
 343     // check if lifetime has been overriden
 344     if (!empty($CFG->mnetkeylifetime)) {
 345         $days = $CFG->mnetkeylifetime;
 346     }
 347
 348     $host = strtolower($CFG->wwwroot);
 349     $host = preg_replace("~^http(s)?://~",'',$host);
 350     $break = strpos($host.'/' , '/');
 351     $host   = substr($host, 0, $break);
 352
 353     $site = get_site();
 354     $organization = $site->fullname;
 355
 356     $keypair = array();
 357
 358     $country  = 'NZ';
 359     $province = 'Wellington';
 360     $locality = 'Wellington';
 361     $email    = !empty($CFG->noreplyaddress) ? $CFG->noreplyaddress : 'noreply@'.$_SERVER['HTTP_HOST'];
 362
 363     if(!empty($USER->country)) {
 364         $country  = $USER->country;
 365     }
 366     if(!empty($USER->city)) {
 367         $province = $USER->city;
 368         $locality = $USER->city;
 369     }
 370     if(!empty($USER->email)) {
 371         $email    = $USER->email;
 372     }
 373
 374     if (is_null($dn)) {
 375         $dn = array(
 376            "countryName" => $country,
 377            "stateOrProvinceName" => $province,
 378            "localityName" => $locality,
 379            "organizationName" => $organization,
 380            "organizationalUnitName" => 'Moodle',
 381            "commonName" => substr($CFG->wwwroot, 0, 64),
 382            "subjectAltName" => $CFG->wwwroot,
 383            "emailAddress" => $email
 384         );
 385     }
 386
 387     $dnlimits = array(
 388            'countryName'            => 2,
 389            'stateOrProvinceName'    => 128,
 390            'localityName'           => 128,
 391            'organizationName'       => 64,
 392            'organizationalUnitName' => 64,
 393            'commonName'             => 64,
 394            'emailAddress'           => 128
 395     );
 396
 397     foreach ($dnlimits as $key => $length) {
 398         $dn[$key] = core_text::substr($dn[$key], 0, $length);
 399     }
 400
 401     // ensure we remove trailing slashes
 402     $dn["commonName"] = preg_replace(':/$:', '', $dn["commonName"]);
 403     if (!empty($CFG->opensslcnf)) { //allow specification of openssl.cnf especially for Windows installs
 404         $new_key = openssl_pkey_new(array("config" => $CFG->opensslcnf));
 405     } else {
 406         $new_key = openssl_pkey_new();
 407     }
 408     if ($new_key === false) {
 409         // can not generate keys - missing openssl.cnf??
 410         return null;
 411     }
 412     if (!empty($CFG->opensslcnf)) { //allow specification of openssl.cnf especially for Windows installs
 413         $csr_rsc = openssl_csr_new($dn, $new_key, array("config" => $CFG->opensslcnf));
 414         $selfSignedCert = openssl_csr_sign($csr_rsc, null, $new_key, $days, array("config" => $CFG->opensslcnf));
 415     } else {
 416         $csr_rsc = openssl_csr_new($dn, $new_key, array('private_key_bits',2048));
 417         $selfSignedCert = openssl_csr_sign($csr_rsc, null, $new_key, $days);
 418     }
 419     unset($csr_rsc); // Free up the resource
 420
 421     // We export our self-signed certificate to a string.
 422     openssl_x509_export($selfSignedCert, $keypair['certificate']);
 423     // TODO: Remove this block once PHP 8.0 becomes required.
 424     if (PHP_MAJOR_VERSION < 8) {
 425         openssl_x509_free($selfSignedCert);
 426     }
 427
 428     // Export your public/private key pair as a PEM encoded string. You
 429     // can protect it with an optional passphrase if you wish.
 430     if (!empty($CFG->opensslcnf)) { //allow specification of openssl.cnf especially for Windows installs
 431         $export = openssl_pkey_export($new_key, $keypair['keypair_PEM'], null, array("config" => $CFG->opensslcnf));
 432     } else {
 433         $export = openssl_pkey_export($new_key, $keypair['keypair_PEM'] /* , $passphrase */);
 434     }
 435     // TODO: Remove this block once PHP 8.0 becomes required.
 436     if (PHP_MAJOR_VERSION < 8) {
 437         openssl_pkey_free($new_key);
 438     }
 439     unset($new_key); // Free up the resource
 440
 441     return $keypair;
 442 }
 443
 444
 445 function mnet_update_sso_access_control($username, $mnet_host_id, $accessctrl) {
 446     global $DB;
 447
 448     $mnethost = $DB->get_record('mnet_host', array('id'=>$mnet_host_id));
 449     if ($aclrecord = $DB->get_record('mnet_sso_access_control', array('username'=>$username, 'mnet_host_id'=>$mnet_host_id))) {
 450         // Update.
 451         $aclrecord->accessctrl = $accessctrl;
 452         $DB->update_record('mnet_sso_access_control', $aclrecord);
 453
 454         // Trigger access control updated event.
 455         $params = array(
 456             'objectid' => $aclrecord->id,
 457             'context' => context_system::instance(),
 458             'other' => array(
 459                 'username' => $username,
 460                 'hostname' => $mnethost->name,
 461                 'accessctrl' => $accessctrl
 462             )
 463         );
 464         $event = \core\event\mnet_access_control_updated::create($params);
 465         $event->add_record_snapshot('mnet_host', $mnethost);
 466         $event->trigger();
 467     } else {
 468         // Insert.
 469         $aclrecord = new stdClass();
 470         $aclrecord->username = $username;
 471         $aclrecord->accessctrl = $accessctrl;
 472         $aclrecord->mnet_host_id = $mnet_host_id;
 473         $aclrecord->id = $DB->insert_record('mnet_sso_access_control', $aclrecord);
 474
 475         // Trigger access control created event.
 476         $params = array(
 477             'objectid' => $aclrecord->id,
 478             'context' => context_system::instance(),
 479             'other' => array(
 480                 'username' => $username,
 481                 'hostname' => $mnethost->name,
 482                 'accessctrl' => $accessctrl
 483             )
 484         );
 485         $event = \core\event\mnet_access_control_created::create($params);
 486         $event->add_record_snapshot('mnet_host', $mnethost);
 487         $event->trigger();
 488     }
 489     return true;
 490 }
 491
 492 function mnet_get_peer_host ($mnethostid) {
 493     global $DB;
 494     static $hosts;
 495     if (!isset($hosts[$mnethostid])) {
 496         $host = $DB->get_record('mnet_host', array('id' => $mnethostid));
 497         $hosts[$mnethostid] = $host;
 498     }
 499     return $hosts[$mnethostid];
 500 }
 501
 502 /**
 503  * Inline function to modify a url string so that mnet users are requested to
 504  * log in at their mnet identity provider (if they are not already logged in)
 505  * before ultimately being directed to the original url.
 506  *
 507  * @param string $jumpurl the url which user should initially be directed to.
 508  *     This is a URL associated with a moodle networking peer when it
 509  *     is fulfiling a role as an identity provider (IDP). Different urls for
 510  *     different peers, the jumpurl is formed partly from the IDP's webroot, and
 511  *     partly from a predefined local path within that webwroot.
 512  *     The result of the user hitting this jump url is that they will be asked
 513  *     to login (at their identity provider (if they aren't already)), mnet
 514  *     will prepare the necessary authentication information, then redirect
 515  *     them back to somewhere at the content provider(CP) moodle (this moodle)
 516  * @param array $url array with 2 elements
 517  *     0 - context the url was taken from, possibly just the url, possibly href="url"
 518  *     1 - the destination url
 519  * @return string the url the remote user should be supplied with.
 520  */
 521 function mnet_sso_apply_indirection ($jumpurl, $url) {
 522     global $USER, $CFG;
 523
 524     $localpart='';
 525     $urlparts = parse_url($url[1]);
 526     if($urlparts) {
 527         if (isset($urlparts['path'])) {
 528             $path = $urlparts['path'];
 529             // if our wwwroot has a path component, need to strip that path from beginning of the
 530             // 'localpart' to make it relative to moodle's wwwroot
 531             $wwwrootpath = parse_url($CFG->wwwroot, PHP_URL_PATH);
 532             if (!empty($wwwrootpath) and strpos($path, $wwwrootpath) === 0) {
 533                 $path = substr($path, strlen($wwwrootpath));
 534             }
 535             $localpart .= $path;
 536         }
 537         if (isset($urlparts['query'])) {
 538             $localpart .= '?'.$urlparts['query'];
 539         }
 540         if (isset($urlparts['fragment'])) {
 541             $localpart .= '#'.$urlparts['fragment'];
 542         }
 543     }
 544     $indirecturl = $jumpurl . urlencode($localpart);
 545     //If we matched on more than just a url (ie an html link), return the url to an href format
 546     if ($url[0] != $url[1]) {
 547         $indirecturl = 'href="'.$indirecturl.'"';
 548     }
 549     return $indirecturl;
 550 }
 551
 552 function mnet_get_app_jumppath ($applicationid) {
 553     global $DB;
 554     static $appjumppaths;
 555     if (!isset($appjumppaths[$applicationid])) {
 556         $ssojumpurl = $DB->get_field('mnet_application', 'sso_jump_url', array('id' => $applicationid));
 557         $appjumppaths[$applicationid] = $ssojumpurl;
 558     }
 559     return $appjumppaths[$applicationid];
 560 }
 561
 562
 563 /**
 564  * Output debug information about mnet.  this will go to the <b>error_log</b>.
 565  *
 566  * @param mixed $debugdata this can be a string, or array or object.
 567  * @param int   $debuglevel optional , defaults to 1. bump up for very noisy debug info
 568  */
 569 function mnet_debug($debugdata, $debuglevel=1) {
 570     global $CFG;
 571     $setlevel = get_config('', 'mnet_rpcdebug');
 572     if (empty($setlevel) || $setlevel < $debuglevel) {
 573         return;
 574     }
 575     if (is_object($debugdata)) {
 576         $debugdata = (array)$debugdata;
 577     }
 578     if (is_array($debugdata)) {
 579         mnet_debug('DUMPING ARRAY');
 580         foreach ($debugdata as $key => $value) {
 581             mnet_debug("$key: $value");
 582         }
 583         mnet_debug('END DUMPING ARRAY');
 584         return;
 585     }
 586     $prefix = 'MNET DEBUG ';
 587     if (defined('MNET_SERVER')) {
 588         $prefix .= " (server $CFG->wwwroot";
 589         if ($peer = get_mnet_remote_client() && !empty($peer->wwwroot)) {
 590             $prefix .= ", remote peer " . $peer->wwwroot;
 591         }
 592         $prefix .= ')';
 593     } else {
 594         $prefix .= " (client $CFG->wwwroot) ";
 595     }
 596     error_log("$prefix $debugdata");
 597 }
 598
 599 /**
 600  * Return an array of information about all moodle's profile fields
 601  * which ones are optional, which ones are forced.
 602  * This is used as the basis of providing lists of profile fields to the administrator
 603  * to pick which fields to import/export over MNET
 604  *
 605  * @return array(forced => array, optional => array)
 606  */
 607 function mnet_profile_field_options() {
 608     global $DB;
 609     static $info;
 610     if (!empty($info)) {
 611         return $info;
 612     }
 613
 614     $excludes = array(
 615         'id',              // makes no sense
 616         'mnethostid',      // makes no sense
 617         'timecreated',     // will be set to relative to the host anyway
 618         'timemodified',    // will be set to relative to the host anyway
 619         'auth',            // going to be set to 'mnet'
 620         'deleted',         // we should never get deleted users sent over, but don't send this anyway
 621         'confirmed',       // unconfirmed users can't log in to their home site, all remote users considered confirmed
 622         'password',        // no password for mnet users
 623         'theme',           // handled separately
 624         'lastip',          // will be set to relative to the host anyway
 625     );
 626
 627     // these are the ones that user_not_fully_set_up will complain about
 628     // and also special case ones
 629     $forced = array(
 630         'username',
 631         'email',
 632         'firstname',
 633         'lastname',
 634         'auth',
 635         'wwwroot',
 636         'session.gc_lifetime',
 637         '_mnet_userpicture_timemodified',
 638         '_mnet_userpicture_mimetype',
 639     );
 640
 641     // these are the ones we used to send/receive (pre 2.0)
 642     $legacy = array(
 643         'username',
 644         'email',
 645         'auth',
 646         'deleted',
 647         'firstname',
 648         'lastname',
 649         'city',
 650         'country',
 651         'lang',
 652         'timezone',
 653         'description',
 654         'mailformat',
 655         'maildigest',
 656         'maildisplay',
 657         'htmleditor',
 658         'wwwroot',
 659         'picture',
 660     );
 661
 662     // get a random user record from the database to pull the fields off
 663     $randomuser = $DB->get_record('user', array(), '*', IGNORE_MULTIPLE);
 664     foreach ($randomuser as $key => $discard) {
 665         if (in_array($key, $excludes) || in_array($key, $forced)) {
 666             continue;
 667         }
 668         $fields[$key] = $key;
 669     }
 670     $info = array(
 671         'forced'   => $forced,
 672         'optional' => $fields,
 673         'legacy'   => $legacy,
 674     );
 675     return $info;
 676 }
 677
 678
 679 /**
 680  * Returns information about MNet peers
 681  *
 682  * @param bool $withdeleted should the deleted peers be returned too
 683  * @return array
 684  */
 685 function mnet_get_hosts($withdeleted = false) {
 686     global $CFG, $DB;
 687
 688     $sql = "SELECT h.id, h.deleted, h.wwwroot, h.ip_address, h.name, h.public_key, h.public_key_expires,
 689                    h.transport, h.portno, h.last_connect_time, h.last_log_id, h.applicationid,
 690                    a.name as app_name, a.display_name as app_display_name, a.xmlrpc_server_url
 691               FROM {mnet_host} h
 692               JOIN {mnet_application} a ON h.applicationid = a.id
 693              WHERE h.id <> ?";
 694
 695     if (!$withdeleted) {
 696         $sql .= "  AND h.deleted = 0";
 697     }
 698
 699     $sql .= " ORDER BY h.deleted, h.name, h.id";
 700
 701     return $DB->get_records_sql($sql, array($CFG->mnet_localhost_id));
 702 }
 703
 704
 705 /**
 706  * return an array information about services enabled for the given peer.
 707  * in two modes, fulldata or very basic data.
 708  *
 709  * @param mnet_peer $mnet_peer the peer to get information abut
 710  * @param boolean   $fulldata whether to just return which services are published/subscribed, or more information (defaults to full)
 711  *
 712  * @return array  If $fulldata is false, an array is returned like:
 713  *                publish => array(
 714  *                    serviceid => boolean,
 715  *                    serviceid => boolean,
 716  *                ),
 717  *                subscribe => array(
 718  *                    serviceid => boolean,
 719  *                    serviceid => boolean,
 720  *                )
 721  *                If $fulldata is true, an array is returned like:
 722  *                servicename => array(
 723  *                   apiversion => array(
 724  *                        name           => string
 725  *                        offer          => boolean
 726  *                        apiversion     => int
 727  *                        plugintype     => string
 728  *                        pluginname     => string
 729  *                        hostsubscribes => boolean
 730  *                        hostpublishes  => boolean
 731  *                   ),
 732  *               )
 733  */
 734 function mnet_get_service_info(mnet_peer $mnet_peer, $fulldata=true) {
 735     global $CFG, $DB;
 736
 737     $requestkey = (!empty($fulldata) ? 'fulldata' : 'mydata');
 738
 739     static $cache = array();
 740     if (array_key_exists($mnet_peer->id, $cache)) {
 741         return $cache[$mnet_peer->id][$requestkey];
 742     }
 743
 744     $id_list = $mnet_peer->id;
 745     if (!empty($CFG->mnet_all_hosts_id)) {
 746         $id_list .= ', '.$CFG->mnet_all_hosts_id;
 747     }
 748
 749     $concat = $DB->sql_concat('COALESCE(h2s.id,0) ', ' \'-\' ', ' svc.id', '\'-\'', 'r.plugintype', '\'-\'', 'r.pluginname');
 750
 751     $query = "
 752         SELECT DISTINCT
 753             $concat as id,
 754             svc.id as serviceid,
 755             svc.name,
 756             svc.offer,
 757             svc.apiversion,
 758             r.plugintype,
 759             r.pluginname,
 760             h2s.hostid,
 761             h2s.publish,
 762             h2s.subscribe
 763         FROM
 764             {mnet_service2rpc} s2r,
 765             {mnet_rpc} r,
 766             {mnet_service} svc
 767         LEFT JOIN
 768             {mnet_host2service} h2s
 769         ON
 770             h2s.hostid in ($id_list) AND
 771             h2s.serviceid = svc.id
 772         WHERE
 773             svc.offer = '1' AND
 774             s2r.serviceid = svc.id AND
 775             s2r.rpcid = r.id
 776         ORDER BY
 777             svc.name ASC";
 778
 779     $resultset = $DB->get_records_sql($query);
 780
 781     if (is_array($resultset)) {
 782         $resultset = array_values($resultset);
 783     } else {
 784         $resultset = array();
 785     }
 786
 787     require_once $CFG->dirroot.'/mnet/xmlrpc/client.php';
 788
 789     $remoteservices = array();
 790     if ($mnet_peer->id != $CFG->mnet_all_hosts_id) {
 791         // Create a new request object
 792         $mnet_request = new mnet_xmlrpc_client();
 793
 794         // Tell it the path to the method that we want to execute
 795         $mnet_request->set_method('system/listServices');
 796         $mnet_request->send($mnet_peer);
 797         if (is_array($mnet_request->response)) {
 798             foreach($mnet_request->response as $service) {
 799                 $remoteservices[$service['name']][$service['apiversion']] = $service;
 800             }
 801         }
 802     }
 803
 804     $myservices = array();
 805     $mydata = array();
 806     foreach($resultset as $result) {
 807         $result->hostpublishes  = false;
 808         $result->hostsubscribes = false;
 809         if (isset($remoteservices[$result->name][$result->apiversion])) {
 810             if ($remoteservices[$result->name][$result->apiversion]['publish'] == 1) {
 811                 $result->hostpublishes  = true;
 812             }
 813             if ($remoteservices[$result->name][$result->apiversion]['subscribe'] == 1) {
 814                 $result->hostsubscribes  = true;
 815             }
 816         }
 817
 818         if (empty($myservices[$result->name][$result->apiversion])) {
 819             $myservices[$result->name][$result->apiversion] = array('serviceid' => $result->serviceid,
 820                                                                     'name' => $result->name,
 821                                                                     'offer' => $result->offer,
 822                                                                     'apiversion' => $result->apiversion,
 823                                                                     'plugintype' => $result->plugintype,
 824                                                                     'pluginname' => $result->pluginname,
 825                                                                     'hostsubscribes' => $result->hostsubscribes,
 826                                                                     'hostpublishes' => $result->hostpublishes
 827                                                                     );
 828         }
 829
 830         // allhosts_publish allows us to tell the admin that even though he
 831         // is disabling a service, it's still available to the host because
 832         // he's also publishing it to 'all hosts'
 833         if ($result->hostid == $CFG->mnet_all_hosts_id && $CFG->mnet_all_hosts_id != $mnet_peer->id) {
 834             $myservices[$result->name][$result->apiversion]['allhosts_publish'] = $result->publish;
 835             $myservices[$result->name][$result->apiversion]['allhosts_subscribe'] = $result->subscribe;
 836         } elseif (!empty($result->hostid)) {
 837             $myservices[$result->name][$result->apiversion]['I_publish'] = $result->publish;
 838             $myservices[$result->name][$result->apiversion]['I_subscribe'] = $result->subscribe;
 839         }
 840         $mydata['publish'][$result->serviceid] = $result->publish;
 841         $mydata['subscribe'][$result->serviceid] = $result->subscribe;
 842
 843     }
 844
 845     $cache[$mnet_peer->id]['fulldata'] = $myservices;
 846     $cache[$mnet_peer->id]['mydata'] = $mydata;
 847
 848     return $cache[$mnet_peer->id][$requestkey];
 849 }
 850
 851 /**
 852  * return an array of the profile fields to send
 853  * with user information to the given mnet host.
 854  *
 855  * @param mnet_peer $peer the peer to send the information to
 856  *
 857  * @return array (like 'username', 'firstname', etc)
 858  */
 859 function mnet_fields_to_send(mnet_peer $peer) {
 860     return _mnet_field_helper($peer, 'export');
 861 }
 862
 863 /**
 864  * return an array of the profile fields to import
 865  * from the given host, when creating/updating user accounts
 866  *
 867  * @param mnet_peer $peer the peer we're getting the information from
 868  *
 869  * @return array (like 'username', 'firstname', etc)
 870  */
 871 function mnet_fields_to_import(mnet_peer $peer) {
 872     return _mnet_field_helper($peer, 'import');
 873 }
 874
 875 /**
 876  * helper for {@see mnet_fields_to_import} and {@mnet_fields_to_send}
 877  *
 878  * @access private
 879  *
 880  * @param mnet_peer $peer the peer object
 881  * @param string    $key 'import' or 'export'
 882  *
 883  * @return array (like 'username', 'firstname', etc)
 884  */
 885 function _mnet_field_helper(mnet_peer $peer, $key) {
 886     $tmp = mnet_profile_field_options();
 887     $defaults = explode(',', get_config('moodle', 'mnetprofile' . $key . 'fields'));
 888     if ('1' === get_config('mnet', 'host' . $peer->id . $key . 'default')) {
 889         return array_merge($tmp['forced'], $defaults);
 890     }
 891     $hostsettings = get_config('mnet', 'host' . $peer->id . $key . 'fields');
 892     if (false === $hostsettings) {
 893         return array_merge($tmp['forced'], $defaults);
 894     }
 895     return array_merge($tmp['forced'], explode(',', $hostsettings));
 896 }
 897
 898
 899 /**
 900  * given a user object (or array) and a list of allowed fields,
 901  * strip out all the fields that should not be included.
 902  * This can be used both for outgoing data and incoming data.
 903  *
 904  * @param mixed $user array or object representing a database record
 905  * @param array $fields an array of allowed fields (usually from mnet_fields_to_{send,import}
 906  *
 907  * @return mixed array or object, depending what type of $user object was passed (datatype is respected)
 908  */
 909 function mnet_strip_user($user, $fields) {
 910     if (is_object($user)) {
 911         $user = (array)$user;
 912         $wasobject = true; // so we can cast back before we return
 913     }
 914
 915     foreach ($user as $key => $value) {
 916         if (!in_array($key, $fields)) {
 917             unset($user[$key]);
 918         }
 919     }
 920     if (!empty($wasobject)) {
 921         $user = (object)$user;
 922     }
 923     return $user;
 924 }