includes/dbal.php
author Dan
Fri, 05 Oct 2007 01:57:00 -0400
changeset 161 e1a22031b5bd
parent 142 ca9118d9c0f2
child 165 d53cc29308f4
child 203 acb9d021b860
permissions -rw-r--r--
Major revamps to the template parser. Fixed a few security holes that could allow PHP to be injected in untimely places in TPL code. Improved Ux for XSS attempt in tplWikiFormat. Documented many functions. Backported much cleaner parser from 2.0 branch. Beautified a lot of code in the depths of the template class. Pretty much a small-scale Extreme Makeover.

<?php

/*
 * Enano - an open-source CMS capable of wiki functions, Drupal-like sidebar blocks, and everything in between
 * Version 1.0.2 (Coblynau)
 * Copyright (C) 2006-2007 Dan Fuhry
 *
 * This program is Free Software; you can redistribute and/or modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied
 * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for details.
 */
 
function db_error_handler($errno, $errstr, $errfile = false, $errline = false, $errcontext = Array() )
{
  if ( !defined('ENANO_DEBUG') )
    return;
  $e = error_reporting(0);
  error_reporting($e);
  if ( $e < $errno )
    return;
  $errtype = 'Notice';
  switch ( $errno )
  {
    case E_ERROR: case E_USER_ERROR: case E_CORE_ERROR: case E_COMPILE_ERROR: $errtype = 'Error'; break;
    case E_WARNING: case E_USER_WARNING: case E_CORE_WARNING: case E_COMPILE_WARNING: $errtype = 'Warning'; break;
  }
  $debug = debug_backtrace();
  $debug = $debug[2]['file'] . ', line ' . $debug[2]['line'];
  echo "<b>$errtype:</b> $errstr<br />Error source:<pre>$debug</pre>";
}
 
class mysql {
  var $num_queries, $query_backtrace, $latest_result, $latest_query, $_conn, $sql_stack_fields, $sql_stack_values;
  var $row = array();
	var $rowset = array();
  var $errhandler;
  
  function enable_errorhandler()
  {
    if ( function_exists('debug_backtrace') )
    {
      $this->errhandler = set_error_handler('db_error_handler');
    }
  }
  
  function disable_errorhandler()
  {
    if ( $this->errhandler )
    {
      set_error_handler($this->errhandler);
    }
    else
    {
      restore_error_handler();
    }
  }
  
  function sql_backtrace() {
    $qb = explode("\n", $this->query_backtrace);
    $bt = '';
    //for($i=sizeof($qb)-1;$i>=0;$i--) {
    for($i=0;$i<sizeof($qb);$i++) {
      $bt .= $qb[$i]."\n";
    }
    return $bt;
  }
  
  function ensure_connection()
  {
    if(!$this->_conn)
    {
      $this->connect();
    }
  }
  
  function _die($t = '') {
    if(defined('ENANO_HEADERS_SENT')) {
      ob_clean();
    }
    header('HTTP/1.1 500 Internal Server Error');
    $bt = $this->latest_query; // $this->sql_backtrace();
    $e = htmlspecialchars(mysql_error());
    if($e=='') $e='&lt;none&gt;';
    $t = ( !empty($t) ) ? $t : '&lt;No error description provided&gt;';
    global $email;
    $email_info = ( defined('ENANO_CONFIG_FETCHED') && is_object($email) ) ? ', at &lt;' . $email->jscode() . $email->encryptEmail(getConfig('contact_email')) . '&gt;' : '';
    $internal_text = '<h3>The site was unable to finish serving your request.</h3>
                      <p>We apologize for the inconveience, but an error occurred in the Enano database layer. Please report the full text of this page to the administrator of this site' . $email_info . '.</p>
                      <p>Description or location of error: '.$t.'<br />
                      Error returned by MySQL extension: ' . $e . '<br />
                      Most recent SQL query:</p>
                      <pre>'.$bt.'</pre>';
    if(defined('ENANO_CONFIG_FETCHED')) die_semicritical('Database error', $internal_text);
    else                                   grinding_halt('Database error', $internal_text);
    exit;
  }
  
  function die_json()
  {
    $e = addslashes(htmlspecialchars(mysql_error()));
    $q = addslashes($this->latest_query);
    $t = "{'mode':'error','error':'An error occurred during database query.\nQuery was:\n  $q\n\nError returned by MySQL: $e'}";
    die($t);
  }
  
  function get_error($t = '') {
    header('HTTP/1.1 500 Internal Server Error');
    $bt = $this->sql_backtrace();
    $e = htmlspecialchars(mysql_error());
    if($e=='') $e='&lt;none&gt;';
    global $email;
    $email_info = ( defined('ENANO_CONFIG_FETCHED') && is_object($email) ) ? ', at &lt;' . $email->jscode() . $email->encryptEmail(getConfig('contact_email')) . '&gt;' : '';
    $internal_text = '<h3>The site was unable to finish serving your request.</h3>
                      <p>We apologize for the inconveience, but an error occurred in the Enano database layer. Please report the full text of this page to the administrator of this site' . $email_info . '.</p>
                      <p>Description or location of error: '.$t.'<br />
                      Error returned by MySQL extension: ' . $e . '<br />
                      Most recent SQL query:</p>
                      <pre>'.$bt.'</pre>';
    return $internal_text;
  }
  
  function connect() {
    $this->enable_errorhandler();
    dc_here('dbal: trying to connect....');
    @include(ENANO_ROOT.'/config.php');
    if(isset($crypto_key))
      unset($crypto_key); // Get this sucker out of memory fast
    if(!defined('ENANO_INSTALLED') && !defined('MIDGET_INSTALLED') && !defined('IN_ENANO_INSTALL') )
    {
      dc_here('dbal: oops, looks like Enano isn\'t set up. Constants ENANO_INSTALLED, MIDGET_INSTALLED, and IN_ENANO_INSTALL are all undefined.');
      header('Location: install.php'); 
      exit;
    }
    $this->_conn = @mysql_connect($dbhost, $dbuser, $dbpasswd);
    unset($dbuser);
    unset($dbpasswd); // Security
    if(!$this->_conn) { dc_here('dbal: uhoh!<br />'.mysql_error()); grinding_halt('Enano is having a problem', '<p>Error: couldn\'t connect to MySQL.<br />'.mysql_error().'</p>'); }
    $this->query_backtrace = '';
    $this->num_queries = 0;
    dc_here('dbal: we\'re in, selecting database...');
    $q = $this->sql_query('USE '.$dbname.';');
    if(!$q) $this->_die('The database could not be selected.');
    dc_here('dbal: connected to MySQL');
    $this->disable_errorhandler();
  }
  
  function sql_query($q) {
    $this->enable_errorhandler();
    $this->num_queries++;
    $this->query_backtrace .= $q."\n";
    $this->latest_query = $q;
    dc_here('dbal: making SQL query:<br /><tt>'.$q.'</tt>');
    if(!$this->_conn) $this->_die('A database connection has not yet been established.');
    if(!$this->check_query($q))
    {
      $this->report_query($q);
      grinding_halt('SQL Injection attempt', '<p>Enano has caught and prevented an SQL injection attempt. Your IP address has been recorded and the administrator has been notified.</p><p>Query was:</p><pre>'.htmlspecialchars($q).'</pre>');
    }
    $r = mysql_query($q, $this->_conn);
    $this->latest_result = $r;
    $this->disable_errorhandler();
    return $r;
  }
  
  function sql_unbuffered_query($q) {
    $this->enable_errorhandler();
    $this->num_queries++;
    $this->query_backtrace .= '(UNBUFFERED) ' . $q."\n";
    $this->latest_query = $q;
    dc_here('dbal: making SQL query:<br /><tt>'.$q.'</tt>');
    if(!$this->_conn) $this->_die('A database connection has not yet been established.');
    if(!$this->check_query($q))
    {
      $this->report_query($q);
      grinding_halt('SQL Injection attempt', '<p>Enano has caught and prevented an SQL injection attempt. Your IP address has been recorded and the administrator has been notified.</p><p>Query was:</p><pre>'.htmlspecialchars($q).'</pre>');
    }
    $r = mysql_unbuffered_query($q, $this->_conn);
    $this->latest_result = $r;
    $this->disable_errorhandler();
    return $r;
  }
  
  /**
   * Checks a SQL query for possible signs of injection attempts
   * @param string $q the query to check
   * @return bool true if query passed check, otherwise false
   */
  
  function check_query($q, $debug = false)
  {
    if($debug) echo "\$db-&gt;check_query(): checking query: ".htmlspecialchars($q).'<br />'."\n";
    $sz = strlen($q);
    $quotechar = false;
    $quotepos  = 0;
    $prev_is_quote = false;
    $just_started = false;
    for ( $i = 0; $i < strlen($q); $i++, $c = substr($q, $i, 1) )
    {
      $next = substr($q, $i+1, 1);
      $next2 = substr($q, $i+2, 1);
      $prev = substr($q, $i-1, 1);
      $prev2 = substr($q, $i-2, 1);
      if(isset($c) && in_array($c, Array('"', "'", '`')))
      {
        if($quotechar)
        {
          if (
              ( $quotechar == $c && $quotechar != $next && ( $quotechar != $prev || $just_started ) && $prev != '\\') ||
              ( $prev2 == '\\' && $prev == $quotechar && $quotechar == $c )
            )
          {
            $quotechar = false;
            if($debug) echo('$db-&gt;check_query(): just finishing a quote section, quoted string: '.htmlspecialchars(substr($q, $quotepos, $i - $quotepos + 1)) . '<br />');
            $q = substr($q, 0, $quotepos) . 'SAFE_QUOTE' . substr($q, $i + 1, strlen($q));
            if($debug) echo('$db-&gt;check_query(): Filtered query: '.$q.'<br />');
            $i = $quotepos;
          }
        }
        else
        {
          $quotechar = $c;
          $quotepos  = $i;
          $just_started = true;
        }
        if($debug) echo '$db-&gt;check_query(): found quote char as pos: '.$i.'<br />';
        continue;
      }
      $just_started = false;
    }
    if(substr(trim($q), strlen(trim($q))-1, 1) == ';') $q = substr(trim($q), 0, strlen(trim($q))-1);
    for($i=0;$i<strlen($q);$i++,$c=substr($q, $i, 1))
    {
      if ( 
           ( ( $c == ';' && $i != $sz-1 ) || $c . substr($q, $i+1, 1) == '--' )
        || ( in_array($c, Array('"', "'", '`')) )
         ) // Don't permit semicolons in mid-query, and never allow comments
      {
        // Injection attempt!
        if($debug)
        {
          $e = '';
          for($j=$i-5;$j<$i+5;$j++)
          {
            if($j == $i) $e .= '<span style="color: red; text-decoration: underline;">' . $c . '</span>';
            else $e .= $c;
          }
          echo 'Injection attempt caught at pos: '.$i.'<br />';
        }
        return false;
      }
    }
    if ( preg_match('/[\s]+(SAFE_QUOTE|[\S]+)=\\1($|[\s]+)/', $q, $match) )
    {
      if ( $debug ) echo 'Found always-true test in query, injection attempt caught, match:<br />' . '<pre>' . print_r($match, true) . '</pre>';
      return false;
    }
    return true;
  }
  
  /**
   * Set the internal result pointer to X
   * @param int $pos The number of the row
   * @param resource $result The MySQL result resource - if not given, the latest cached query is assumed
   * @return true on success, false on failure
   */
   
  function sql_data_seek($pos, $result = false)
  {
    $this->enable_errorhandler();
    if(!$result)
      $result = $this->latest_result;
    if(!$result)
    {
      $this->disable_errorhandler();
      return false;
    }
    if(mysql_data_seek($result, $pos))
    {
      $this->disable_errorhandler();
      return true;
    }
    else
    {
      $this->disable_errorhandler();
      return false;
    }
  }
  
  /**
   * Reports a bad query to the admin
   * @param string $query the naughty query
   * @access private
   */
   
  function report_query($query)
  {
    global $session;
    if(is_object($session) && defined('ENANO_MAINSTREAM'))
      $username = $session->username;
    else
      $username = 'Unavailable';
    $query = $this->escape($query);
    $q = $this->sql_query('INSERT INTO '.table_prefix.'logs(log_type,     action,         time_id,    date_string, page_text,      author,            edit_summary)
                                                     VALUES(\'security\', \'sql_inject\', '.time().', \'\',        \''.$query.'\', \''.$username.'\', \''.$_SERVER['REMOTE_ADDR'].'\');');
  }
  
  /**
   * Returns the ID of the row last inserted.
   * @return int
   */
  
  function insert_id()
  {
    return @mysql_insert_id();
  }
  
  function fetchrow($r = false) {
    $this->enable_errorhandler();
    if(!$this->_conn) return false;
    if(!$r) $r = $this->latest_result;
    if(!$r) $this->_die('$db->fetchrow(): an invalid MySQL resource was passed.');
    $row = mysql_fetch_assoc($r);
    $this->disable_errorhandler();
    return $row;
  }
  
  function fetchrow_num($r = false) {
    $this->enable_errorhandler();
    if(!$r) $r = $this->latest_result;
    if(!$r) $this->_die('$db->fetchrow(): an invalid MySQL resource was passed.');
    $row = mysql_fetch_row($r);
    $this->disable_errorhandler();
    return $row;
  }
  
  function numrows($r = false) {
    $this->enable_errorhandler();
    if(!$r) $r = $this->latest_result;
    if(!$r) $this->_die('$db->fetchrow(): an invalid MySQL resource was passed.');
    $n = mysql_num_rows($r);
    $this->disable_errorhandler();
    return $n;
  }
  
  function escape($str)
  {
    $this->enable_errorhandler();
    $str = mysql_real_escape_string($str);
    $this->disable_errorhandler();
    return $str;
  }
  
  function free_result($result = false)
  {
    $this->enable_errorhandler();
    if(!$result)
      $result = $this->latest_result;
    if(!$result)
    {
      $this->disable_errorhandler();
      return null;
    }
    mysql_free_result($result);
    $this->disable_errorhandler();
    return null;
  }
  
  function close() {
    dc_here('dbal: closing MySQL connection');
    mysql_close($this->_conn);
    unset($this->_conn);
  }
  
  // phpBB DBAL compatibility
  function sql_fetchrow($r = false)
  {
    return $this->fetchrow($r);
  }
  function sql_freeresult($r = false)
  {
    if(!$this->_conn) return false;
    if(!$r) $r = $this->latest_result;
    if(!$r) $this->_die('$db->fetchrow(): an invalid MySQL resource was passed.');
    mysql_free_result($r);
  }
  function sql_numrows($r = false)
  {
    if(!$this->_conn) return false;
    if(!$r) $r = $this->latest_result;
    if(!$r) $this->_die('$db->fetchrow(): an invalid MySQL resource was passed.');
    return mysql_num_rows($r);
  }
  function sql_affectedrows($r = false, $f, $n)
  {
    if(!$this->_conn) return false;
    if(!$r) $r = $this->latest_result;
    if(!$r) $this->_die('$db->fetchrow(): an invalid MySQL resource was passed.');
    return mysql_affected_rows();
  }
  
  function sql_type_cast(&$value)
	{
		if ( is_float($value) )
		{
			return doubleval($value);
		}
		if ( is_integer($value) || is_bool($value) )
		{
			return intval($value);
		}
		if ( is_string($value) || empty($value) )
		{
			return '\'' . $this->sql_escape_string($value) . '\'';
		}
		// uncastable var : let's do a basic protection on it to prevent sql injection attempt
		return '\'' . $this->sql_escape_string(htmlspecialchars($value)) . '\'';
	}

	function sql_statement(&$fields, $fields_inc='')
	{
		// init result
		$this->sql_fields = $this->sql_values = $this->sql_update = '';
		if ( empty($fields) && empty($fields_inc) )
		{
			return;
		}

		// process
		if ( !empty($fields) )
		{
			$first = true;
			foreach ( $fields as $field => $value )
			{
				// field must contain a field name
				if ( !empty($field) && is_string($field) )
				{
					$value = $this->sql_type_cast($value);
					$this->sql_fields .= ( $first ? '' : ', ' ) . $field;
					$this->sql_values .= ( $first ? '' : ', ' ) . $value;
					$this->sql_update .= ( $first ? '' : ', ' ) . $field . ' = ' . $value;
					$first = false;
				}
			}
		}
		if ( !empty($fields_inc) )
		{
			foreach ( $fields_inc as $field => $indent )
			{
				if ( $indent != 0 )
				{
					$this->sql_update .= (empty($this->sql_update) ? '' : ', ') . $field . ' = ' . $field . ($indent < 0 ? ' - ' : ' + ') . abs($indent);
				}
			}
		}
	}

	function sql_stack_reset($id='')
	{
		if ( empty($id) )
		{
			$this->sql_stack_fields = array();
			$this->sql_stack_values = array();
		}
		else
		{
			$this->sql_stack_fields[$id] = array();
			$this->sql_stack_values[$id] = array();
		}
	}

	function sql_stack_statement(&$fields, $id='')
	{
		$this->sql_statement($fields);
		if ( empty($id) )
		{
			$this->sql_stack_fields = $this->sql_fields;
			$this->sql_stack_values[] = '(' . $this->sql_values . ')';
		}
		else
		{
			$this->sql_stack_fields[$id] = $this->sql_fields;
			$this->sql_stack_values[$id][] = '(' . $this->sql_values . ')';
		}
	}

	function sql_stack_insert($table, $transaction=false, $line='', $file='', $break_on_error=true, $id='')
	{
		if ( (empty($id) && empty($this->sql_stack_values)) || (!empty($id) && empty($this->sql_stack_values[$id])) )
		{
			return false;
		}
		switch( SQL_LAYER )
		{
			case 'mysql':
			case 'mysql4':
				if ( empty($id) )
				{
					$sql = 'INSERT INTO ' . $table . '
								(' . $this->sql_stack_fields . ') VALUES ' . implode(",\n", $this->sql_stack_values);
				}
				else
				{
					$sql = 'INSERT INTO ' . $table . '
								(' . $this->sql_stack_fields[$id] . ') VALUES ' . implode(",\n", $this->sql_stack_values[$id]);
				}
				$this->sql_stack_reset($id);
				return $this->sql_query($sql, $transaction, $line, $file, $break_on_error);
				break;
			default:
				$count_sql_stack_values = empty($id) ? count($this->sql_stack_values) : count($this->sql_stack_values[$id]);
				$result = !empty($count_sql_stack_values);
				for ( $i = 0; $i < $count_sql_stack_values; $i++ )
				{
					if ( empty($id) )
					{
						$sql = 'INSERT INTO ' . $table . '
									(' . $this->sql_stack_fields . ') VALUES ' . $this->sql_stack_values[$i];
					}
					else
					{
						$sql = 'INSERT INTO ' . $table . '
									(' . $this->sql_stack_fields[$id] . ') VALUES ' . $this->sql_stack_values[$id][$i];
					}
					$result &= $this->sql_query($sql, $transaction, $line, $file, $break_on_error);
				}
				$this->sql_stack_reset($id);
				return $result;
				break;
		}
	}

	function sql_subquery($field, $sql, $line='', $file='', $break_on_error=true, $type=TYPE_INT)
	{
		// sub-queries doable
		$this->sql_get_version();
		if ( !in_array(SQL_LAYER, array('mysql', 'mysql4')) || (($this->sql_version[0] + ($this->sql_version[1] / 100)) >= 4.01) )
		{
			return $sql;
		}

		// no sub-queries
		$ids = array();
		$result = $this->sql_query(trim($sql), false, $line, $file, $break_on_error);
		while ( $row = $this->sql_fetchrow($result) )
		{
			$ids[] = $type == TYPE_INT ? intval($row[$field]) : '\'' . $this->sql_escape_string($row[$field]) . '\'';
		}
		$this->sql_freeresult($result);
		return empty($ids) ? 'NULL' : implode(', ', $ids);
	}

	function sql_col_id($expr, $alias)
	{
		$this->sql_get_version();
		return in_array(SQL_LAYER, array('mysql', 'mysql4')) && (($this->sql_version[0] + ($this->sql_version[1] / 100)) <= 4.01) ? $alias : $expr;
	}

	function sql_get_version()
	{
		if ( empty($this->sql_version) )
		{
			$this->sql_version = array(0, 0, 0);
			switch ( SQL_LAYER )
			{
				case 'mysql':
				case 'mysql4':
					if ( function_exists('mysql_get_server_info') )
					{
						$lo_version = explode('-', mysql_get_server_info());
						$this->sql_version = explode('.', $lo_version[0]);
						$this->sql_version = array(intval($this->sql_version[0]), intval($this->sql_version[1]), intval($this->sql_version[2]), $lo_version[1]);
					}
					break;

				case 'postgresql':
				case 'mssql':
				case 'mssql-odbc':
				default:
					break;
			}
		}
		return $this->sql_version;
	}

	function sql_error()
	{
		if ( $this->_conn )
		{
			return mysql_error();
		}
		else
		{
			return array();
		}
	}
  function sql_escape_string($t) 
  {
    return mysql_real_escape_string($t);
  }
  function sql_close()
  {
    $this->close();
  }
  function sql_fetchrowset($query_id = 0)
	{
		if( !$query_id )
		{
			$query_id = $this->query_result;
		}

		if( $query_id )
		{
			unset($this->rowset[$query_id]);
			unset($this->row[$query_id]);

			while($this->rowset[$query_id] = mysql_fetch_array($query_id, MYSQL_ASSOC))
			{
				$result[] = $this->rowset[$query_id];
			}

			return $result;
		}
		else
		{
			return false;
		}
	}
}

?>