library/ESign/DbRow/Signable.php

   1 <?php
   2
   3 namespace ESign;
   4
   5 /**
   6  * Abstract implementation of SignableIF which represents a signable row
   7  * in the database.
   8  *
   9  * Copyright (C) 2013 OEMR 501c3 www.oemr.org
  10  *
  11  * LICENSE: This program is free software; you can redistribute it and/or
  12  * modify it under the terms of the GNU General Public License
  13  * as published by the Free Software Foundation; either version 3
  14  * of the License, or (at your option) any later version.
  15  * This program is distributed in the hope that it will be useful,
  16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  18  * GNU General Public License for more details.
  19  * You should have received a copy of the GNU General Public License
  20  * along with this program. If not, see <http://opensource.org/licenses/gpl-license.php>;.
  21  *
  22  * @package OpenEMR
  23  * @author  Ken Chapple <ken@mi-squared.com>
  24  * @author  Medical Information Integration, LLC
  25  * @link    http://www.open-emr.org
  26  **/
  27
  28 require_once $GLOBALS['srcdir'].'/ESign/SignableIF.php';
  29 require_once $GLOBALS['srcdir'].'/ESign/Signature.php';
  30 require_once $GLOBALS['srcdir'].'/ESign/Utils/Verification.php';
  31
  32 abstract class DbRow_Signable implements SignableIF
  33 {
  34     private $_signatures = array();
  35     private $_tableId = null;
  36     private $_tableName = null;
  37     private $_verification = null;
  38
  39     public function __construct($tableId, $tableName)
  40     {
  41         $this->_tableId = $tableId;
  42         $this->_tableName = $tableName;
  43         $this->_verification = new Utils_Verification();
  44     }
  45
  46     public function getSignatures()
  47     {
  48         $this->_signatures = array();
  49
  50         $statement = "SELECT E.id, E.tid, E.table, E.uid, U.fname, U.lname, E.datetime, E.is_lock, E.amendment, E.hash, E.signature_hash FROM esign_signatures E ";
  51         $statement .= "JOIN users U ON E.uid = U.id ";
  52         $statement .= "WHERE E.tid = ? AND E.table = ? ";
  53         $statement .= "ORDER BY E.datetime ASC";
  54         $result = sqlStatement($statement, array( $this->_tableId, $this->_tableName ));
  55
  56         while ($row = sqlFetchArray($result)) {
  57             $signature = new Signature(
  58                 $row['id'],
  59                 $row['tid'],
  60                 $row['table'],
  61                 $row['is_lock'],
  62                 $row['uid'],
  63                 $row['fname'],
  64                 $row['lname'],
  65                 $row['datetime'],
  66                 $row['hash'],
  67                 $row['amendment'],
  68                 $row['signature_hash']
  69             );
  70             $this->_signatures[]= $signature;
  71         }
  72
  73         return $this->_signatures;
  74     }
  75
  76     /**
  77      * Get the hash of the last signature of type LOCK.
  78      *
  79      * This is used for comparison with a current hash to
  80      * verify data integrity.
  81      *
  82      * @return sha1|empty string
  83      */
  84     protected function getLastLockHash()
  85     {
  86         $statement = "SELECT E.tid, E.table, E.hash FROM esign_signatures E ";
  87         $statement .= "WHERE E.tid = ? AND E.table = ? AND E.is_lock = ? ";
  88         $statement .= "ORDER BY E.datetime DESC LIMIT 1";
  89         $row = sqlQuery($statement, array( $this->_tableId, $this->_tableName, SignatureIF::ESIGN_LOCK ));
  90         $hash = null;
  91         if ($row && isset($row['hash'])) {
  92             $hash = $row['hash'];
  93         }
  94
  95         return $hash;
  96     }
  97
  98     public function getTableId()
  99     {
 100         return $this->_tableId;
 101     }
 102
 103     public function renderForm()
 104     {
 105         include 'views/esign_signature_log.php';
 106     }
 107
 108     public function isLocked()
 109     {
 110         $statement = "SELECT E.is_lock FROM esign_signatures E ";
 111         $statement .= "WHERE E.tid = ? AND E.table = ? AND is_lock = ? ";
 112         $statement .= "ORDER BY E.datetime DESC LIMIT 1 ";
 113         $row = sqlQuery($statement, array( $this->_tableId, $this->_tableName, SignatureIF::ESIGN_LOCK ));
 114         if ($row && $row['is_lock'] == SignatureIF::ESIGN_LOCK) {
 115             return true;
 116         }
 117
 118         return false;
 119     }
 120
 121     public function sign($userId, $lock = false, $amendment = null)
 122     {
 123         $statement = "INSERT INTO `esign_signatures` ( `tid`, `table`, `uid`, `datetime`, `is_lock`, `hash`, `amendment`, `signature_hash` ) ";
 124         $statement .= "VALUES ( ?, ?, ?, NOW(), ?, ?, ?, ? ) ";
 125
 126         // Make type string
 127         $isLock = SignatureIF::ESIGN_NOLOCK;
 128         if ($lock) {
 129             $isLock = SignatureIF::ESIGN_LOCK;
 130         }
 131
 132         // Create a hash of the signable object so we can verify it's integrity
 133         $hash = $this->_verification->hash($this->getData());
 134
 135         // Crate a hash of the signature data itself. This is the same data as Signature::getData() method
 136         $signature = array(
 137             $this->_tableId,
 138             $this->_tableName,
 139             $userId,
 140             $isLock,
 141             $hash,
 142             $amendment );
 143         $signatureHash = $this->_verification->hash($signature);
 144
 145         // Append the hash of the signature data to the insert array before we insert
 146         $signature[]= $signatureHash;
 147         $id = sqlInsert($statement, $signature);
 148
 149         if ($id === false) {
 150             throw new \Exception("Error occured while attempting to insert a signature into the database.");
 151         }
 152
 153         return $id;
 154     }
 155
 156     public function verify()
 157     {
 158         $valid = true;
 159         // Verify the signable data integrity
 160         // Check to see if this SignableIF is locked
 161         if ($this->isLocked()) {
 162             $signatures = $this->getSignatures();
 163
 164             // SignableIF is locked, so if it has any signatures, make sure it hasn't been edited since lock
 165             if (count($signatures)) {
 166                 // Verify the data of the SignableIF object
 167                 $lastLockHash = $this->getLastLockHash();
 168                 $valid = $this->_verification->verify($this->getData(), $lastLockHash);
 169
 170                 if ($valid === true) {
 171                     // If still vlaid, verify each signatures' integrity
 172                     foreach ($signatures as $signature) {
 173                         if ($signature instanceof SignatureIF) {
 174                             $valid = $signature->verify();
 175                             if ($valid === false) {
 176                                 break;
 177                             }
 178                         }
 179                     }
 180                 }
 181             }
 182         }
 183
 184         return $valid;
 185     }
 186 }