License
* - http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
*/
require_once("../../config.php");
global $DB;
//Debug: debug iLM security scheme
//Debug: ATTENTION, this requests the directory './mod/iassign/ilm_debug/' with write permition to www-data !!!!
$DEBUG = 0; //Debug: help to debug, register data in file 'MOODLE/mod/iassign/ilm_debug/YYYY_mm_dd_m_s_int'
class ilm_security {
// Table 'iassign_security' : id iassign_statementid userid file timecreated view
/// Since we are using {iassign_security}.file (to store the iLM text content) with as 'utf8mb4_unicode_ci'
/// to avoid error "Error writing to database"!"Incorrect string value" lets ensure to use UTF-8
// Considering only 'ISO-8859-1'
static function convert2utf8 ($strcontent) {
// $current_encoding = mb_detect_encoding($strcontent, ['ASCII', 'UTF-8', 'ISO-8859-1']); // 'ASCII', 'UTF-8' and 'ISO-8859-1'
$current_encoding = mb_detect_encoding($strcontent, 'ISO-8859-1'); // 'ASCII', 'UTF-8' and 'ISO-8859-1'
$converted_text_to_utf8 = iconv($current_encoding, 'UTF-8', $strcontent); // converted to UTF-8
//D echo "ilm_security.php:
current_encoding=" . $current_encoding . ", new_encoding=" . $new_encoding . "
";
//D echo "strcontent[0,200]=" . substr($strcontent, 0, 200) . "
";
//D echo "converted_text_to_utf8[0,200]=" . substr($converted_text_to_utf8, 0, 200) . "
---
";
return $converted_text_to_utf8;
}
/// Warning message
static function warning_message_iassign ($strcode) { // errado no 'locallib.php' sempre com constante 'error_view_without_actiontype'!!!
return "" . get_string($strcode, 'iassign') . "
\n";
}
// @calledby here : after print $strFileContent;
static function remove_records ($userid) { //, $iassign_statementid
if (!isset($userid) || !isset($iassign_statementid)) {
// self::warning_message_iassign('???');
print self::warning_message_iassign('error_security_no_userid'); // 'Internal error: must be informed the user identification. Inform the Administrator.'
return null;
}
if (!isset($iassign_statementid) || $iassign_statementid<1)
$array_param = array("userid" => $userid); // erase all entries of this user
else
$array_param = array("userid" => $userid, "iassign_statementid" => $iassign_statementid);
$DB->delete_records("iassign_security", $array_param); // erase only for this iAssign activity
}
// @calledby locallib.php : class ilm : function view_iLM($iassign_statement_activity_item, $student_answer, $enderecoPOST, $view)
static function remove_old_iLM_security_entries ($userid) { // substituir 'locallib' de mesmo nome!
global $DB;
// This is an additional security: erase eventually old entries in 'iassign_security' table (do not remove '$iassign_statementid' since it is going to be used "now")
$result = $DB->delete_records_select("iassign_security", "userid=" . $userid . " AND view>1", null);
}
/// Function to give a single access to an iLM content avoi (after used, 'view()', after 'view_iLM(...)', will erase the entry)
// @calledby locallib.php : class ilm_manager : function preview_ilm($courseid, $iassign_ilm): $id_iLM_security = ilm_security::write_iLM_security($USER->id, $timecreated, -1, $content_or_id_from_ilm_security);
// @param int $iassign_statement_activity_itemid Id of iassign statement, when from iLM 'preview' (there is none activity), -1
// @param Object $file File in use in activity
// @return int Return the id of log
static function write_iLM_security ($userid, $timecreated, $iassign_statementid = -1, $content_or_id_from_ilm_security = "") {
global $DB;
$newentry = new stdClass();
$newentry->iassign_statementid = $iassign_statementid; // when came from iLM previw => there is none activity, use -1
$newentry->userid = $userid;
//_ $newentry->file = $content_or_id_from_ilm_security;
if (!$content_or_id_from_ilm_security)
return null; // avoid error trying to load empty content
$newentry->file = ilm_security::convert2utf8($content_or_id_from_ilm_security); // must be utf8mb4_unicode_ci
$newentry->timecreated = $timecreated; // who calls will generate: $timecreated = time(); $token == md5($timecreated);
$newentry->view = 1;
$id_iLM_security = $DB->insert_record("iassign_security", $newentry); // insert into {iassign_security}
if (!$id_iLM_security) {
print_error('error_security', 'iassign'); // ./lib/setuplib.php: moodle_exception thrown
}
return $id_iLM_security;
}
} // class ilm_security
$view = optional_param('view', NULL, PARAM_TEXT); //$view = $_GET['view'];
$token = optional_param('token', NULL, PARAM_TEXT); //$token = $_GET['token'];
$id = optional_param('id', NULL, PARAM_TEXT); //$id = $_GET['id']; //id of the table iassign_security
$stringDebugAux = "";
$strFileContent = "";
//DEBUG
if ($DEBUG) {
$file_name = "ilm_debug/" . date('Y') . "_" . date('m') . "_" . date('d') . "_" . date('H_i') . "_" . $id;
$file_debug = "id=" . $id . "
\nview=" . $view . "
\ntoken=" . $token;
$stringDebugAux = "user.id=" . $USER->id . ", user.name=" . $USER->firstname . " " . $USER->lastname . "\n";
}
if ($view == -1) { // view free
$fs = get_file_storage();
$file = $fs->get_file_by_id($id);
$strFileContent .= $file->get_content();
$stringDebugAux .= "1: file content:" . $strFileContent; //DEBUG
print $strFileContent;
ilm_security::remove_old_iLM_security_entries($USER->id); // for security reason erase the used entry in 'iassign_security' (and others for this user/activity)
}
else {
// Get data from table 'iassign_security'
$iassign_security = $DB->get_record("iassign_security", array("id" => $id)); // id iassign_statementid userid file timecreated view
if ($DEBUG) { //DEBUG
$strAux = "iassign_security = { id=" . $iassign_security->id . ", " . $iassign_security->iassign_statementid . ", | " . $iassign_security->file . " |, " . $iassign_security->view . " }";
$stringDebugAux .= $strAux;
}
if ($iassign_security) {
$fileid = $iassign_security->file;
if ($iassign_security) { //TODO must be 'if ($fileid)'?
$update = new stdClass();
$update->id = $iassign_security->id;
$update->view = $iassign_security->view + 1;
$DB->update_record("iassign_security", $update);
if ($DEBUG) $stringDebugAux .= " view++ = " . $iassign_security->view . "\n";
if ($update->view >= 2 && $token == md5($iassign_security->timecreated)) { //
// Security iLM: remove the entry
if ($view) {
// If it is view of the exercise, then get it on the Moodle data (usually '/var/moodledata') => file is a number = '*_files.id'
// If it is learner answer get it in data base => file is the iLM file content
// $stringDebugAuxFile = ""; //Debug
$fs = get_file_storage();
$file_moodledata = $fs->get_file_by_id($fileid);
$strFileContent = $file_moodledata->get_content();
$stringDebugAuxFile = $file_moodledata->get_filename() . "/"; //Debug
if ($DEBUG) { //DEBUG
$stringDebugAux .= "view>=2: view=$view: update->view=" . $update->view . "\n" . $token . "=" . md5($iassign_security->timecreated) . "?\n";
}
} // if ($update->view == 2 && $token == md5($iassign_security->timecreated))
else { // not view - get the student content answer
// *_iassign_security : id iassign_statementid userid file timecreated view (where 'file' is longtext utf8_unicode_ci)
$strFileContent = $iassign_security->file; //ERROR: use some filter, remove '.', '/' and other special characters
//$strFileContent = $contextid; - this also do NOT work!!
if ($DEBUG) { //DEBUG
$stringDebugAux .= "view>=2: else view=$view: update->view=" . $update->view . "\n" . $token . "=" . md5($iassign_security->timecreated) . "?\n";
$stringDebugAux .= " " . $iassign_security->id . ", " . $iassign_security->timecreated . "\n";
}
}
// Here is the print to the iLM request the content
print $strFileContent; // Important: to iAssign sent to the iLM its content
// Effectively erase the content just read (for security reason)
ilm_security::remove_old_iLM_security_entries($USER->id); // for security reason erase the used entry in 'iassign_security' (and others for this user/activity)
} // if ($update->view == 2 && $token == md5($iassign_security->timecreated))
else {
if ($DEBUG) { //DEBUG
$countF = 0;
foreach ($files as $thefile) {
$strFileName = $thefile->get_filename(); //Debug
$stringDebugAux .= " " . ($countF++) . ": " . $strFileName . "\n";
$stringDebugAuxFile = $strFileName . "/"; //Debug
if ($strFileName != '.') {
$strFileContent = $thefile->get_content();
}
}
$stringDebugAux .= "view<=2: NOT update->view=" . $update->view . "\n" . $token . "=" . md5($iassign_security->timecreated) . "?\nstrFileContent=" . $strFileContent . "\n";
}
}
} // if ($iassign_security)
} // if ($iassign_security)
}
// Attention, do not use 'print' nor 'echo' here, since this could mixed up the iLM reading its content!
if ($DEBUG) { //DEBUG
$fpointer = fopen($file_name, "w");
$file_debug .= "\nAuxiliary information: " . $stringDebugAux . "";
$file_debug .= "\nContent iLM file: |" . $strFileContent . "|";
fwrite($fpointer, "From: ./mod/iassign/ilm_security.php
\n" . $file_debug);
fclose($fpointer);
}