<?php

/*

 * Enano - an open-source CMS capable of wiki functions, Drupal-like sidebar blocks, and everything in between

 * Version 1.0.1 (Loch Ness)

 * 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='<none>';

    if(defined('ENANO_CONFIG_FETCHED')) die_semicritical('Database error', '<h3>An error occurred during a database query.</h3><p>'.$t.'<br />Error returned by MySQL: '.$e.'<br />SQL Backtrace:</p><pre>'.$bt.'</pre>');

    else                                   grinding_halt('Database error', '<h3>An error occurred during a database query.</h3><p>'.$t.'<br />Error returned by MySQL: '.$e.'<br />SQL Backtrace:</p><pre>'.$bt.'</pre>');

    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='<none>';

    $text = '<h3>An error occurred during a database query.</h3><p>'.$t.'<br />Error returned by MySQL: '.$e.'<br />SQL Backtrace:</p><pre>'.$bt.'</pre>';

    return $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_entered ) && $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_entered = true;

        }

        if($debug) echo '$db-&gt;check_query(): found quote char as pos: '.$i.'<br />';

        continue;

      }

      $just_entered = 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) == '--') // 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;

      }

    }

    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);