library/log_validation.php

   1 <?php
   2 /**
   3  * library/log_validation.php to validate audit logs tamper resistance.
   4  *
   5  * Copyright (C) 2016 Visolve <services@visolve.com>
   6  *
   7  * LICENSE: This program is free software; you can redistribute it and/or
   8  * modify it under the terms of the GNU General Public License
   9  * as published by the Free Software Foundation; either version 3
  10  * of the License, or (at your option) any later version.
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  14  * GNU General Public License for more details.
  15  * You should have received a copy of the GNU General Public License
  16  * along with this program. If not, see <http://opensource.org/licenses/gpl-license.php>;.
  17  *
  18  * @package OpenEMR
  19  * @author  Visolve <services@visolve.com>
  20  * @link    http://www.open-emr.org
  21  */
  22
  23
  24
  25
  26 require_once("../interface/globals.php");
  27 require_once("$srcdir/log.inc");
  28
  29
  30     $valid  = true;
  31     $errors = array();
  32     catch_logs();
  33     $sql = sqlStatement("select * from log_validator");
  34 while ($row = sqlFetchArray($sql)) {
  35     $logEntry = sqlQuery("select * from log where id = ?", array($row['log_id']));
  36     if (empty($logEntry)) {
  37         $valid = false;
  38         array_push($errors, xl("Following audit log entry number is missing") . ": " . $row['log_id']);
  39     } else if ($row['log_checksum'] != $logEntry['checksum']) {
  40         $valid = false;
  41         array_push($errors, xl("Audit log tampering evident at entry number") . " " . $row['log_id']);
  42     }
  43
  44     if (!$valid) {
  45         break;
  46     }
  47 }
  48
  49 if ($valid) {
  50     echo xl("Audit Log Validated Successfully");
  51 } else {
  52     echo xl("Audit Log Validation Failed") . "(ERROR:: $errors[0])";
  53 }
  54
  55 function catch_logs()
  56 {
  57     $sql  = sqlStatement("select * from log where id not in(select log_id from log_validator) and checksum is NOT null and checksum != ''");
  58     while ($row = sqlFetchArray($sql)) {
  59         sqlInsert("INSERT into log_validator (log_id,log_checksum) VALUES(?,?)", array($row['id'],$row['checksum']));
  60     }
  61 }