Drop all PHP 5.3-related code

22 files changed, 19 insertions, 1049 deletions

diff --git a/system/core/CodeIgniter.php b/system/core/CodeIgniter.php
index 97cac90ad..dfc90af2a 100644
--- a/system/core/CodeIgniter.php
+++ b/system/core/CodeIgniter.php
@@ -79,57 +79,6 @@ defined('BASEPATH') OR exit('No direct script access allowed');
  */
 	require_once(BASEPATH.'core/Common.php');
 
-
-/*
- * ------------------------------------------------------
- * Security procedures
- * ------------------------------------------------------
- */
-
-if ( ! is_php('5.4'))
-{
-	ini_set('magic_quotes_runtime', 0);
-
-	if ((bool) ini_get('register_globals'))
-	{
-		$_protected = array(
-			'_SERVER',
-			'_GET',
-			'_POST',
-			'_FILES',
-			'_REQUEST',
-			'_SESSION',
-			'_ENV',
-			'_COOKIE',
-			'GLOBALS',
-			'HTTP_RAW_POST_DATA',
-			'system_path',
-			'application_folder',
-			'view_folder',
-			'_protected',
-			'_registered'
-		);
-
-		$_registered = ini_get('variables_order');
-		foreach (array('E' => '_ENV', 'G' => '_GET', 'P' => '_POST', 'C' => '_COOKIE', 'S' => '_SERVER') as $key => $superglobal)
-		{
-			if (strpos($_registered, $key) === FALSE)
-			{
-				continue;
-			}
-
-			foreach (array_keys($$superglobal) as $var)
-			{
-				if (isset($GLOBALS[$var]) && ! in_array($var, $_protected, TRUE))
-				{
-					$GLOBALS[$var] = NULL;
-				}
-			}
-		}
-	}
-}
-
-
 /*
  * ------------------------------------------------------
  *  Define a custom error handler so we can log PHP errors
diff --git a/system/core/Common.php b/system/core/Common.php
index 91c585f7d..48eb233c2 100644
--- a/system/core/Common.php
+++ b/system/core/Common.php
@@ -81,8 +81,7 @@ if ( ! function_exists('is_really_writable'))
 	 * Tests for file writability
 	 *
 	 * is_writable() returns TRUE on Windows servers when you really can't write to
-	 * the file, based on the read-only attribute. is_writable() is also unreliable
-	 * on Unix servers if safe_mode is on.
+	 * the file, based on the read-only attribute.
 	 *
 	 * @link	https://bugs.php.net/bug.php?id=54709
 	 * @param	string
@@ -90,8 +89,8 @@ if ( ! function_exists('is_really_writable'))
 	 */
 	function is_really_writable($file)
 	{
-		// If we're on a Unix server with safe_mode off we call is_writable
-		if (DIRECTORY_SEPARATOR === '/' && (is_php('5.4') OR ! ini_get('safe_mode')))
+		// If we're on a UNIX-like server, just is_writable()
+		if (DIRECTORY_SEPARATOR === '/')
 		{
 			return is_writable($file);
 		}
diff --git a/system/core/Loader.php b/system/core/Loader.php
index 1111481b7..b52296499 100644
--- a/system/core/Loader.php
+++ b/system/core/Loader.php
@@ -954,7 +954,7 @@ class CI_Loader {
 		}
 		extract($this->_ci_cached_vars);
 
-		/*
+		/**
 		 * Buffer the output
 		 *
 		 * We buffer the output for two reasons:
@@ -967,18 +967,7 @@ class CI_Loader {
 		 */
 		ob_start();
 
-		// If the PHP installation does not support short tags we'll
-		// do a little string replacement, changing the short tags
-		// to standard PHP echo statements.
-		if ( ! is_php('5.4') && ! ini_get('short_open_tag') && config_item('rewrite_short_tags') === TRUE)
-		{
-			echo eval('?>'.preg_replace('/;*\s*\?>/', '; ?>', str_replace('<?=', '<?php echo ', file_get_contents($_ci_path))));
-		}
-		else
-		{
-			include($_ci_path); // include() vs include_once() allows for multiple views with the same name
-		}
-
+		include($_ci_path); // include() vs include_once() allows for multiple views with the same name
 		log_message('info', 'File loaded: '.$_ci_path);
 
 		// Return the file data if requested
diff --git a/system/core/Log.php b/system/core/Log.php
index cf6c75a95..902162647 100644
--- a/system/core/Log.php
+++ b/system/core/Log.php
@@ -283,9 +283,6 @@ class CI_Log {
 	{
 		if (self::$func_override)
 		{
-			// mb_substr($str, $start, null, '8bit') returns an empty
-			// string on PHP 5.3
-			isset($length) OR $length = ($start >= 0 ? self::strlen($str) - $start : -$start);
 			return mb_substr($str, $start, $length, '8bit');
 		}
 
diff --git a/system/core/Output.php b/system/core/Output.php
index 94a6340e7..febccdaef 100644
--- a/system/core/Output.php
+++ b/system/core/Output.php
@@ -836,9 +836,6 @@ class CI_Output {
 	{
 		if (self::$func_override)
 		{
-			// mb_substr($str, $start, null, '8bit') returns an empty
-			// string on PHP 5.3
-			isset($length) OR $length = ($start >= 0 ? self::strlen($str) - $start : -$start);
 			return mb_substr($str, $start, $length, '8bit');
 		}
 
diff --git a/system/core/Security.php b/system/core/Security.php
index d0308c5f9..a80b52fd1 100644
--- a/system/core/Security.php
+++ b/system/core/Security.php
@@ -626,7 +626,7 @@ class CI_Security {
 		if (is_readable('/dev/urandom') && ($fp = fopen('/dev/urandom', 'rb')) !== FALSE)
 		{
 			// Try not to waste entropy ...
-			is_php('5.4') && stream_set_chunk_size($fp, $length);
+			stream_set_chunk_size($fp, $length);
 			$output = fread($fp, $length);
 			fclose($fp);
 			if ($output !== FALSE)
@@ -671,26 +671,8 @@ class CI_Security {
 
 		static $_entities;
 
-		isset($charset) OR $charset = $this->charset;
-		$flag = is_php('5.4')
-			? ENT_COMPAT | ENT_HTML5
-			: ENT_COMPAT;
-
-		if ( ! isset($_entities))
-		{
-			$_entities = array_map('strtolower', get_html_translation_table(HTML_ENTITIES, $flag, $charset));
-
-			// If we're not on PHP 5.4+, add the possibly dangerous HTML 5
-			// entities to the array manually
-			if ($flag === ENT_COMPAT)
-			{
-				$_entities[':'] = '&colon;';
-				$_entities['('] = '&lpar;';
-				$_entities[')'] = '&rpar;';
-				$_entities["\n"] = '&NewLine;';
-				$_entities["\t"] = '&Tab;';
-			}
-		}
+		isset($charset)   OR $charset = $this->charset;
+		isset($_entities) OR $_entities = array_map('strtolower', get_html_translation_table(HTML_ENTITIES, ENT_COMPAT | ENT_HTML5, $charset));
 
 		do
 		{
@@ -715,14 +697,9 @@ class CI_Security {
 			// Decode numeric & UTF16 two byte entities
 			$str = html_entity_decode(
 				preg_replace('/(&#(?:x0*[0-9a-f]{2,5}(?![0-9a-f;])|(?:0*\d{2,4}(?![0-9;]))))/iS', '$1;', $str),
-				$flag,
+				ENT_COMPAT | ENT_HTML5,
 				$charset
 			);
-
-			if ($flag === ENT_COMPAT)
-			{
-				$str = str_replace(array_values($_entities), array_keys($_entities), $str);
-			}
 		}
 		while ($str_compare !== $str);
 		return $str;
@@ -1074,5 +1051,4 @@ class CI_Security {
 
 		return $this->_csrf_hash;
 	}
-
 }
diff --git a/system/core/compat/hash.php b/system/core/compat/hash.php
index d567d0f80..5fec4cc67 100644
--- a/system/core/compat/hash.php
+++ b/system/core/compat/hash.php
@@ -203,8 +203,6 @@ if ( ! function_exists('hash_pbkdf2'))
 			'ripemd160' => 64,
 			'ripemd256' => 64,
 			'ripemd320' => 64,
-			'salsa10' => 64,
-			'salsa20' => 64,
 			'sha1' => 64,
 			'sha224' => 64,
 			'sha256' => 64,
diff --git a/system/core/compat/password.php b/system/core/compat/password.php
index 1b5219e7b..e58422557 100644
--- a/system/core/compat/password.php
+++ b/system/core/compat/password.php
@@ -141,7 +141,7 @@ if ( ! function_exists('password_hash'))
 				}
 
 				// Try not to waste entropy ...
-				is_php('5.4') && stream_set_chunk_size($fp, 16);
+				stream_set_chunk_size($fp, 16);
 
 				$options['salt'] = '';
 				for ($read = 0; $read < 16; $read = ($func_override) ? mb_strlen($options['salt'], '8bit') : strlen($options['salt']))
diff --git a/system/core/compat/standard.php b/system/core/compat/standard.php
index 6b7caa485..ca5046e56 100644
--- a/system/core/compat/standard.php
+++ b/system/core/compat/standard.php
@@ -132,51 +132,3 @@ if ( ! function_exists('array_column'))
 		return $result;
 	}
 }
-
-// ------------------------------------------------------------------------
-
-if (is_php('5.4'))
-{
-	return;
-}
-
-// ------------------------------------------------------------------------
-
-if ( ! function_exists('hex2bin'))
-{
-	/**
-	 * hex2bin()
-	 *
-	 * @link	http://php.net/hex2bin
-	 * @param	string	$data
-	 * @return	string
-	 */
-	function hex2bin($data)
-	{
-		if (in_array($type = gettype($data), array('array', 'double', 'object', 'resource'), TRUE))
-		{
-			if ($type === 'object' && method_exists($data, '__toString'))
-			{
-				$data = (string) $data;
-			}
-			else
-			{
-				trigger_error('hex2bin() expects parameter 1 to be string, '.$type.' given', E_USER_WARNING);
-				return NULL;
-			}
-		}
-
-		if (strlen($data) % 2 !== 0)
-		{
-			trigger_error('Hexadecimal input string must have an even length', E_USER_WARNING);
-			return FALSE;
-		}
-		elseif ( ! preg_match('/^[0-9a-f]*$/i', $data))
-		{
-			trigger_error('Input string must be hexadecimal string', E_USER_WARNING);
-			return FALSE;
-		}
-
-		return pack('H*', $data);
-	}
-}
diff --git a/system/database/drivers/postgre/postgre_driver.php b/system/database/drivers/postgre/postgre_driver.php
index 5cc6a421c..9f794a12e 100644
--- a/system/database/drivers/postgre/postgre_driver.php
+++ b/system/database/drivers/postgre/postgre_driver.php
@@ -315,7 +315,7 @@ class CI_DB_postgre_driver extends CI_DB {
 	 */
 	public function escape($str)
 	{
-		if (is_php('5.4.4') && (is_string($str) OR (is_object($str) && method_exists($str, '__toString'))))
+		if (is_string($str) OR (is_object($str) && method_exists($str, '__toString')))
 		{
 			return pg_escape_literal($this->conn_id, $str);
 		}
diff --git a/system/database/drivers/sqlite/index.html b/system/database/drivers/sqlite/index.html
deleted file mode 100644
index b702fbc39..000000000
--- a/system/database/drivers/sqlite/index.html
+++ /dev/null
@@ -1,11 +0,0 @@
-<!DOCTYPE html>
-<html>
-<head>
-	<title>403 Forbidden</title>
-</head>
-<body>
-
-<p>Directory access is forbidden.</p>
-
-</body>
-</html>
diff --git a/system/database/drivers/sqlite/sqlite_driver.php b/system/database/drivers/sqlite/sqlite_driver.php
deleted file mode 100644
index 16b8c29c3..000000000
--- a/system/database/drivers/sqlite/sqlite_driver.php
+++ /dev/null
@@ -1,330 +0,0 @@
-<?php
-/**
- * CodeIgniter
- *
- * An open source application development framework for PHP
- *
- * This content is released under the MIT License (MIT)
- *
- * Copyright (c) 2014 - 2016, British Columbia Institute of Technology
- *
- * Permission is hereby granted, free of charge, to any person obtaining a copy
- * of this software and associated documentation files (the "Software"), to deal
- * in the Software without restriction, including without limitation the rights
- * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
- * copies of the Software, and to permit persons to whom the Software is
- * furnished to do so, subject to the following conditions:
- *
- * The above copyright notice and this permission notice shall be included in
- * all copies or substantial portions of the Software.
- *
- * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
- * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
- * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
- * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
- * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
- * THE SOFTWARE.
- *
- * @package	CodeIgniter
- * @author	EllisLab Dev Team
- * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2016, British Columbia Institute of Technology (http://bcit.ca/)
- * @license	http://opensource.org/licenses/MIT	MIT License
- * @link	https://codeigniter.com
- * @since	Version 1.3.0
- * @filesource
- */
-defined('BASEPATH') OR exit('No direct script access allowed');
-
-/**
- * SQLite Database Adapter Class
- *
- * Note: _DB is an extender class that the app controller
- * creates dynamically based on whether the query builder
- * class is being used or not.
- *
- * @package		CodeIgniter
- * @subpackage	Drivers
- * @category	Database
- * @author		EllisLab Dev Team
- * @link		https://codeigniter.com/user_guide/database/
- */
-class CI_DB_sqlite_driver extends CI_DB {
-
-	/**
-	 * Database driver
-	 *
-	 * @var	string
-	 */
-	public $dbdriver = 'sqlite';
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * ORDER BY random keyword
-	 *
-	 * @var	array
-	 */
-	protected $_random_keyword = array('RANDOM()', 'RANDOM()');
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Non-persistent database connection
-	 *
-	 * @param	bool	$persistent
-	 * @return	resource
-	 */
-	public function db_connect($persistent = FALSE)
-	{
-		$error = NULL;
-		$conn_id = ($persistent === TRUE)
-			? sqlite_popen($this->database, 0666, $error)
-			: sqlite_open($this->database, 0666, $error);
-
-		isset($error) && log_message('error', $error);
-
-		return $conn_id;
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Database version number
-	 *
-	 * @return	string
-	 */
-	public function version()
-	{
-		return isset($this->data_cache['version'])
-			? $this->data_cache['version']
-			: $this->data_cache['version'] = sqlite_libversion();
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Execute the query
-	 *
-	 * @param	string	$sql	an SQL query
-	 * @return	resource
-	 */
-	protected function _execute($sql)
-	{
-		return $this->is_write_type($sql)
-			? sqlite_exec($this->conn_id, $sql)
-			: sqlite_query($this->conn_id, $sql);
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Begin Transaction
-	 *
-	 * @return	bool
-	 */
-	protected function _trans_begin()
-	{
-		return $this->simple_query('BEGIN TRANSACTION');
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Commit Transaction
-	 *
-	 * @return	bool
-	 */
-	protected function _trans_commit()
-	{
-		return $this->simple_query('COMMIT');
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Rollback Transaction
-	 *
-	 * @return	bool
-	 */
-	protected function _trans_rollback()
-	{
-		return $this->simple_query('ROLLBACK');
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Platform-dependant string escape
-	 *
-	 * @param	string
-	 * @return	string
-	 */
-	protected function _escape_str($str)
-	{
-		return sqlite_escape_string($str);
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Affected Rows
-	 *
-	 * @return	int
-	 */
-	public function affected_rows()
-	{
-		return sqlite_changes($this->conn_id);
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Insert ID
-	 *
-	 * @return	int
-	 */
-	public function insert_id()
-	{
-		return sqlite_last_insert_rowid($this->conn_id);
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * List table query
-	 *
-	 * Generates a platform-specific query string so that the table names can be fetched
-	 *
-	 * @param	bool	$prefix_limit
-	 * @return	string
-	 */
-	protected function _list_tables($prefix_limit = FALSE)
-	{
-		$sql = "SELECT name FROM sqlite_master WHERE type='table'";
-
-		if ($prefix_limit !== FALSE && $this->dbprefix != '')
-		{
-			return $sql." AND 'name' LIKE '".$this->escape_like_str($this->dbprefix)."%' ".sprintf($this->_like_escape_str, $this->_like_escape_chr);
-		}
-
-		return $sql;
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Show column query
-	 *
-	 * Generates a platform-specific query string so that the column names can be fetched
-	 *
-	 * @param	string	$table
-	 * @return	bool
-	 */
-	protected function _list_columns($table = '')
-	{
-		// Not supported
-		return FALSE;
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Returns an object with field data
-	 *
-	 * @param	string	$table
-	 * @return	array
-	 */
-	public function field_data($table)
-	{
-		if (($query = $this->query('PRAGMA TABLE_INFO('.$this->protect_identifiers($table, TRUE, NULL, FALSE).')')) === FALSE)
-		{
-			return FALSE;
-		}
-
-		$query = $query->result_array();
-		if (empty($query))
-		{
-			return FALSE;
-		}
-
-		$retval = array();
-		for ($i = 0, $c = count($query); $i < $c; $i++)
-		{
-			$retval[$i]			= new stdClass();
-			$retval[$i]->name		= $query[$i]['name'];
-			$retval[$i]->type		= $query[$i]['type'];
-			$retval[$i]->max_length		= NULL;
-			$retval[$i]->default		= $query[$i]['dflt_value'];
-			$retval[$i]->primary_key	= isset($query[$i]['pk']) ? (int) $query[$i]['pk'] : 0;
-		}
-
-		return $retval;
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Error
-	 *
-	 * Returns an array containing code and message of the last
-	 * database error that has occured.
-	 *
-	 * @return	array
-	 */
-	public function error()
-	{
-		$error = array('code' => sqlite_last_error($this->conn_id));
-		$error['message'] = sqlite_error_string($error['code']);
-		return $error;
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Replace statement
-	 *
-	 * Generates a platform-specific replace string from the supplied data
-	 *
-	 * @param	string	$table	Table name
-	 * @param	array	$keys	INSERT keys
-	 * @param	array	$values	INSERT values
-	 * @return	string
-	 */
-	protected function _replace($table, $keys, $values)
-	{
-		return 'INSERT OR '.parent::_replace($table, $keys, $values);
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Truncate statement
-	 *
-	 * Generates a platform-specific truncate string from the supplied data
-	 *
-	 * If the database does not support the TRUNCATE statement,
-	 * then this function maps to 'DELETE FROM table'
-	 *
-	 * @param	string	$table
-	 * @return	string
-	 */
-	protected function _truncate($table)
-	{
-		return 'DELETE FROM '.$table;
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Close DB Connection
-	 *
-	 * @return	void
-	 */
-	protected function _close()
-	{
-		sqlite_close($this->conn_id);
-	}
-
-}
diff --git a/system/database/drivers/sqlite/sqlite_forge.php b/system/database/drivers/sqlite/sqlite_forge.php
deleted file mode 100644
index 3ad3477e4..000000000
--- a/system/database/drivers/sqlite/sqlite_forge.php
+++ /dev/null
@@ -1,205 +0,0 @@
-<?php
-/**
- * CodeIgniter
- *
- * An open source application development framework for PHP
- *
- * This content is released under the MIT License (MIT)
- *
- * Copyright (c) 2014 - 2016, British Columbia Institute of Technology
- *
- * Permission is hereby granted, free of charge, to any person obtaining a copy
- * of this software and associated documentation files (the "Software"), to deal
- * in the Software without restriction, including without limitation the rights
- * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
- * copies of the Software, and to permit persons to whom the Software is
- * furnished to do so, subject to the following conditions:
- *
- * The above copyright notice and this permission notice shall be included in
- * all copies or substantial portions of the Software.
- *
- * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
- * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
- * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
- * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
- * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
- * THE SOFTWARE.
- *
- * @package	CodeIgniter
- * @author	EllisLab Dev Team
- * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2016, British Columbia Institute of Technology (http://bcit.ca/)
- * @license	http://opensource.org/licenses/MIT	MIT License
- * @link	https://codeigniter.com
- * @since	Version 1.3.0
- * @filesource
- */
-defined('BASEPATH') OR exit('No direct script access allowed');
-
-/**
- * SQLite Forge Class
- *
- * @category	Database
- * @author		EllisLab Dev Team
- * @link		https://codeigniter.com/user_guide/database/
- */
-class CI_DB_sqlite_forge extends CI_DB_forge {
-
-	/**
-	 * CREATE TABLE IF statement
-	 *
-	 * @var	string
-	 */
-	protected $_create_table_if	= FALSE;
-
-	/**
-	 * UNSIGNED support
-	 *
-	 * @var	bool|array
-	 */
-	protected $_unsigned		= FALSE;
-
-	/**
-	 * NULL value representation in CREATE/ALTER TABLE statements
-	 *
-	 * @var	string
-	 */
-	protected $_null		= 'NULL';
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Create database
-	 *
-	 * @param	string	$db_name	(ignored)
-	 * @return	bool
-	 */
-	public function create_database($db_name)
-	{
-		// In SQLite, a database is created when you connect to the database.
-		// We'll return TRUE so that an error isn't generated
-		return TRUE;
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Drop database
-	 *
-	 * @param	string	$db_name	(ignored)
-	 * @return	bool
-	 */
-	public function drop_database($db_name)
-	{
-		if ( ! file_exists($this->db->database) OR ! @unlink($this->db->database))
-		{
-			return ($this->db->db_debug) ? $this->db->display_error('db_unable_to_drop') : FALSE;
-		}
-		elseif ( ! empty($this->db->data_cache['db_names']))
-		{
-			$key = array_search(strtolower($this->db->database), array_map('strtolower', $this->db->data_cache['db_names']), TRUE);
-			if ($key !== FALSE)
-			{
-				unset($this->db->data_cache['db_names'][$key]);
-			}
-		}
-
-		return TRUE;
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * ALTER TABLE
-	 *
-	 * @todo	implement drop_column(), modify_column()
-	 * @param	string	$alter_type	ALTER type
-	 * @param	string	$table		Table name
-	 * @param	mixed	$field		Column definition
-	 * @return	string|string[]
-	 */
-	protected function _alter_table($alter_type, $table, $field)
-	{
-		if ($alter_type === 'DROP' OR $alter_type === 'CHANGE')
-		{
-			// drop_column():
-			//	BEGIN TRANSACTION;
-			//	CREATE TEMPORARY TABLE t1_backup(a,b);
-			//	INSERT INTO t1_backup SELECT a,b FROM t1;
-			//	DROP TABLE t1;
-			//	CREATE TABLE t1(a,b);
-			//	INSERT INTO t1 SELECT a,b FROM t1_backup;
-			//	DROP TABLE t1_backup;
-			//	COMMIT;
-
-			return FALSE;
-		}
-
-		return parent::_alter_table($alter_type, $table, $field);
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Process column
-	 *
-	 * @param	array	$field
-	 * @return	string
-	 */
-	protected function _process_column($field)
-	{
-		return $this->db->escape_identifiers($field['name'])
-			.' '.$field['type']
-			.$field['auto_increment']
-			.$field['null']
-			.$field['unique']
-			.$field['default'];
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Field attribute TYPE
-	 *
-	 * Performs a data type mapping between different databases.
-	 *
-	 * @param	array	&$attributes
-	 * @return	void
-	 */
-	protected function _attr_type(&$attributes)
-	{
-		switch (strtoupper($attributes['TYPE']))
-		{
-			case 'ENUM':
-			case 'SET':
-				$attributes['TYPE'] = 'TEXT';
-				return;
-			default: return;
-		}
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Field attribute AUTO_INCREMENT
-	 *
-	 * @param	array	&$attributes
-	 * @param	array	&$field
-	 * @return	void
-	 */
-	protected function _attr_auto_increment(&$attributes, &$field)
-	{
-		if ( ! empty($attributes['AUTO_INCREMENT']) && $attributes['AUTO_INCREMENT'] === TRUE && stripos($field['type'], 'int') !== FALSE)
-		{
-			$field['type'] = 'INTEGER PRIMARY KEY';
-			$field['default'] = '';
-			$field['null'] = '';
-			$field['unique'] = '';
-			$field['auto_increment'] = ' AUTOINCREMENT';
-
-			$this->primary_keys = array();
-		}
-	}
-
-}
diff --git a/system/database/drivers/sqlite/sqlite_result.php b/system/database/drivers/sqlite/sqlite_result.php
deleted file mode 100644
index d40b98aab..000000000
--- a/system/database/drivers/sqlite/sqlite_result.php
+++ /dev/null
@@ -1,164 +0,0 @@
-<?php
-/**
- * CodeIgniter
- *
- * An open source application development framework for PHP
- *
- * This content is released under the MIT License (MIT)
- *
- * Copyright (c) 2014 - 2016, British Columbia Institute of Technology
- *
- * Permission is hereby granted, free of charge, to any person obtaining a copy
- * of this software and associated documentation files (the "Software"), to deal
- * in the Software without restriction, including without limitation the rights
- * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
- * copies of the Software, and to permit persons to whom the Software is
- * furnished to do so, subject to the following conditions:
- *
- * The above copyright notice and this permission notice shall be included in
- * all copies or substantial portions of the Software.
- *
- * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
- * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
- * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
- * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
- * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
- * THE SOFTWARE.
- *
- * @package	CodeIgniter
- * @author	EllisLab Dev Team
- * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2016, British Columbia Institute of Technology (http://bcit.ca/)
- * @license	http://opensource.org/licenses/MIT	MIT License
- * @link	https://codeigniter.com
- * @since	Version 1.3.0
- * @filesource
- */
-defined('BASEPATH') OR exit('No direct script access allowed');
-
-/**
- * SQLite Result Class
- *
- * This class extends the parent result class: CI_DB_result
- *
- * @category	Database
- * @author		EllisLab Dev Team
- * @link		https://codeigniter.com/user_guide/database/
- */
-class CI_DB_sqlite_result extends CI_DB_result {
-
-	/**
-	 * Number of rows in the result set
-	 *
-	 * @return	int
-	 */
-	public function num_rows()
-	{
-		return is_int($this->num_rows)
-			? $this->num_rows
-			: $this->num_rows = @sqlite_num_rows($this->result_id);
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Number of fields in the result set
-	 *
-	 * @return	int
-	 */
-	public function num_fields()
-	{
-		return @sqlite_num_fields($this->result_id);
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Fetch Field Names
-	 *
-	 * Generates an array of column names
-	 *
-	 * @return	array
-	 */
-	public function list_fields()
-	{
-		$field_names = array();
-		for ($i = 0, $c = $this->num_fields(); $i < $c; $i++)
-		{
-			$field_names[$i] = sqlite_field_name($this->result_id, $i);
-		}
-
-		return $field_names;
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Field data
-	 *
-	 * Generates an array of objects containing field meta-data
-	 *
-	 * @return	array
-	 */
-	public function field_data()
-	{
-		$retval = array();
-		for ($i = 0, $c = $this->num_fields(); $i < $c; $i++)
-		{
-			$retval[$i]			= new stdClass();
-			$retval[$i]->name		= sqlite_field_name($this->result_id, $i);
-			$retval[$i]->type		= NULL;
-			$retval[$i]->max_length		= NULL;
-		}
-
-		return $retval;
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Data Seek
-	 *
-	 * Moves the internal pointer to the desired offset. We call
-	 * this internally before fetching results to make sure the
-	 * result set starts at zero.
-	 *
-	 * @param	int	$n
-	 * @return	bool
-	 */
-	public function data_seek($n = 0)
-	{
-		return sqlite_seek($this->result_id, $n);
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Result - associative array
-	 *
-	 * Returns the result set as an array
-	 *
-	 * @return	array
-	 */
-	protected function _fetch_assoc()
-	{
-		return sqlite_fetch_array($this->result_id);
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Result - object
-	 *
-	 * Returns the result set as an object
-	 *
-	 * @param	string	$class_name
-	 * @return	object
-	 */
-	protected function _fetch_object($class_name = 'stdClass')
-	{
-		return sqlite_fetch_object($this->result_id, $class_name);
-	}
-
-}
diff --git a/system/database/drivers/sqlite/sqlite_utility.php b/system/database/drivers/sqlite/sqlite_utility.php
deleted file mode 100644
index 59c46f9ef..000000000
--- a/system/database/drivers/sqlite/sqlite_utility.php
+++ /dev/null
@@ -1,61 +0,0 @@
-<?php
-/**
- * CodeIgniter
- *
- * An open source application development framework for PHP
- *
- * This content is released under the MIT License (MIT)
- *
- * Copyright (c) 2014 - 2016, British Columbia Institute of Technology
- *
- * Permission is hereby granted, free of charge, to any person obtaining a copy
- * of this software and associated documentation files (the "Software"), to deal
- * in the Software without restriction, including without limitation the rights
- * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
- * copies of the Software, and to permit persons to whom the Software is
- * furnished to do so, subject to the following conditions:
- *
- * The above copyright notice and this permission notice shall be included in
- * all copies or substantial portions of the Software.
- *
- * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
- * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
- * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
- * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
- * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
- * THE SOFTWARE.
- *
- * @package	CodeIgniter
- * @author	EllisLab Dev Team
- * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2016, British Columbia Institute of Technology (http://bcit.ca/)
- * @license	http://opensource.org/licenses/MIT	MIT License
- * @link	https://codeigniter.com
- * @since	Version 1.3.0
- * @filesource
- */
-defined('BASEPATH') OR exit('No direct script access allowed');
-
-/**
- * SQLite Utility Class
- *
- * @category	Database
- * @author		EllisLab Dev Team
- * @link		https://codeigniter.com/user_guide/database/
- */
-class CI_DB_sqlite_utility extends CI_DB_utility {
-
-	/**
-	 * Export
-	 *
-	 * @param	array	$params	Preferences
-	 * @return	mixed
-	 */
-	protected function _backup($params = array())
-	{
-		// Currently unsupported
-		return $this->db->display_error('db_unsupported_feature');
-	}
-
-}
diff --git a/system/libraries/Email.php b/system/libraries/Email.php
index 90a68f129..1191e2350 100644
--- a/system/libraries/Email.php
+++ b/system/libraries/Email.php
@@ -226,13 +226,6 @@ class CI_Email {
 	// --------------------------------------------------------------------
 
 	/**
-	 * Whether PHP is running in safe mode. Initialized by the class constructor.
-	 *
-	 * @var	bool
-	 */
-	protected $_safe_mode		= FALSE;
-
-	/**
 	 * Subject header
 	 *
 	 * @var	string
@@ -395,7 +388,6 @@ class CI_Email {
 	{
 		$this->charset = config_item('charset');
 		$this->initialize($config);
-		$this->_safe_mode = ( ! is_php('5.4') && ini_get('safe_mode'));
 
 		isset(self::$func_override) OR self::$func_override = (extension_loaded('mbstring') && ini_get('mbstring.func_override'));
 
@@ -676,18 +668,6 @@ class CI_Email {
 	public function message($body)
 	{
 		$this->_body = rtrim(str_replace("\r", '', $body));
-
-		/* strip slashes only if magic quotes is ON
-		   if we do it with magic quotes OFF, it strips real, user-inputted chars.
-
-		   NOTE: In PHP 5.4 get_magic_quotes_gpc() will always return 0 and
-			 it will probably not exist in future versions at all.
-		*/
-		if ( ! is_php('5.4') && get_magic_quotes_gpc())
-		{
-			$this->_body = stripslashes($this->_body);
-		}
-
 		return $this;
 	}
 
@@ -1854,16 +1834,9 @@ class CI_Email {
 			$this->_recipients = implode(', ', $this->_recipients);
 		}
 
-		if ($this->_safe_mode === TRUE)
-		{
-			return mail($this->_recipients, $this->_subject, $this->_finalbody, $this->_header_str);
-		}
-		else
-		{
-			// most documentation of sendmail using the "-f" flag lacks a space after it, however
-			// we've encountered servers that seem to require it to be in place.
-			return mail($this->_recipients, $this->_subject, $this->_finalbody, $this->_header_str, '-f '.$this->clean_email($this->_headers['Return-Path']));
-		}
+		// most documentation of sendmail using the "-f" flag lacks a space after it, however
+		// we've encountered servers that seem to require it to be in place.
+		return mail($this->_recipients, $this->_subject, $this->_finalbody, $this->_header_str, '-f '.$this->clean_email($this->_headers['Return-Path']));
 	}
 
 	// --------------------------------------------------------------------
@@ -2421,9 +2394,6 @@ class CI_Email {
 	{
 		if (self::$func_override)
 		{
-			// mb_substr($str, $start, null, '8bit') returns an empty
-			// string on PHP 5.3
-			isset($length) OR $length = ($start >= 0 ? self::strlen($str) - $start : -$start);
 			return mb_substr($str, $start, $length, '8bit');
 		}
 
diff --git a/system/libraries/Encryption.php b/system/libraries/Encryption.php
index 545081b3b..c68ee2584 100644
--- a/system/libraries/Encryption.php
+++ b/system/libraries/Encryption.php
@@ -482,7 +482,7 @@ class CI_Encryption {
 			$data,
 			$params['handle'],
 			$params['key'],
-			1, // DO NOT TOUCH!
+			OPENSSL_RAW_DATA,
 			$iv
 		);
 
@@ -641,7 +641,7 @@ class CI_Encryption {
 				$data,
 				$params['handle'],
 				$params['key'],
-				1, // DO NOT TOUCH!
+				OPENSSL_RAW_DATA,
 				$iv
 			);
 	}
@@ -930,9 +930,6 @@ class CI_Encryption {
 	{
 		if (self::$func_override)
 		{
-			// mb_substr($str, $start, null, '8bit') returns an empty
-			// string on PHP 5.3
-			isset($length) OR $length = ($start >= 0 ? self::strlen($str) - $start : -$start);
 			return mb_substr($str, $start, $length, '8bit');
 		}
 
diff --git a/system/libraries/Session/Session.php b/system/libraries/Session/Session.php
index 01989d2d7..9d3bd7a2f 100644
--- a/system/libraries/Session/Session.php
+++ b/system/libraries/Session/Session.php
@@ -105,23 +105,7 @@ class CI_Session {
 		$class = new $class($this->_config);
 		if ($class instanceof SessionHandlerInterface)
 		{
-			if (is_php('5.4'))
-			{
-				session_set_save_handler($class, TRUE);
-			}
-			else
-			{
-				session_set_save_handler(
-					array($class, 'open'),
-					array($class, 'close'),
-					array($class, 'read'),
-					array($class, 'write'),
-					array($class, 'destroy'),
-					array($class, 'gc')
-				);
-
-				register_shutdown_function('session_write_close');
-			}
+			session_set_save_handler($class, TRUE);
 		}
 		else
 		{
@@ -190,9 +174,6 @@ class CI_Session {
 	 */
 	protected function _ci_load_classes($driver)
 	{
-		// PHP 5.4 compatibility
-		interface_exists('SessionHandlerInterface', FALSE) OR require_once(BASEPATH.'libraries/Session/SessionHandlerInterface.php');
-
 		$prefix = config_item('subclass_prefix');
 
 		if ( ! class_exists('CI_Session_driver', FALSE))
diff --git a/system/libraries/Session/SessionHandlerInterface.php b/system/libraries/Session/SessionHandlerInterface.php
deleted file mode 100644
index b3533dd1e..000000000
--- a/system/libraries/Session/SessionHandlerInterface.php
+++ /dev/null
@@ -1,59 +0,0 @@
-<?php
-/**
- * CodeIgniter
- *
- * An open source application development framework for PHP
- *
- * This content is released under the MIT License (MIT)
- *
- * Copyright (c) 2014 - 2016, British Columbia Institute of Technology
- *
- * Permission is hereby granted, free of charge, to any person obtaining a copy
- * of this software and associated documentation files (the "Software"), to deal
- * in the Software without restriction, including without limitation the rights
- * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
- * copies of the Software, and to permit persons to whom the Software is
- * furnished to do so, subject to the following conditions:
- *
- * The above copyright notice and this permission notice shall be included in
- * all copies or substantial portions of the Software.
- *
- * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
- * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
- * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
- * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
- * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
- * THE SOFTWARE.
- *
- * @package	CodeIgniter
- * @author	EllisLab Dev Team
- * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
- * @copyright	Copyright (c) 2014 - 2016, British Columbia Institute of Technology (http://bcit.ca/)
- * @license	http://opensource.org/licenses/MIT	MIT License
- * @link	https://codeigniter.com
- * @since	Version 3.0.0
- * @filesource
- */
-defined('BASEPATH') OR exit('No direct script access allowed');
-
-/**
- * SessionHandlerInterface
- *
- * PHP 5.4 compatibility interface
- *
- * @package	CodeIgniter
- * @subpackage	Libraries
- * @category	Sessions
- * @author	Andrey Andreev
- * @link	https://codeigniter.com/user_guide/libraries/sessions.html
- */
-interface SessionHandlerInterface {
-
-	public function open($save_path, $name);
-	public function close();
-	public function read($session_id);
-	public function write($session_id, $session_data);
-	public function destroy($session_id);
-	public function gc($maxlifetime);
-}
diff --git a/system/libraries/Upload.php b/system/libraries/Upload.php
index 490421af9..ac5c9e42d 100644
--- a/system/libraries/Upload.php
+++ b/system/libraries/Upload.php
@@ -1276,7 +1276,7 @@ class CI_Upload {
 				}
 			}
 
-			if ( ! ini_get('safe_mode') && function_usable('shell_exec'))
+			if (function_usable('shell_exec'))
 			{
 				$mime = @shell_exec($cmd);
 				if (strlen($mime) > 0)
diff --git a/system/libraries/Xmlrpc.php b/system/libraries/Xmlrpc.php
index 7186646da..87f609e8d 100644
--- a/system/libraries/Xmlrpc.php
+++ b/system/libraries/Xmlrpc.php
@@ -836,9 +836,7 @@ class XML_RPC_Response
 		{
 			// error
 			$this->errno = $code;
-			$this->errstr = htmlspecialchars($fstr,
-							(is_php('5.4') ? ENT_XML1 | ENT_NOQUOTES : ENT_NOQUOTES),
-							'UTF-8');
+			$this->errstr = htmlspecialchars($fstr, ENT_XML1 | ENT_NOQUOTES, 'UTF-8');
 		}
 		elseif ( ! is_object($val))
 		{
diff --git a/system/libraries/Zip.php b/system/libraries/Zip.php
index 25315c92e..82a43e9c9 100644
--- a/system/libraries/Zip.php
+++ b/system/libraries/Zip.php
@@ -519,9 +519,6 @@ class CI_Zip {
 	{
 		if (self::$func_override)
 		{
-			// mb_substr($str, $start, null, '8bit') returns an empty
-			// string on PHP 5.3
-			isset($length) OR $length = ($start >= 0 ? self::strlen($str) - $start : -$start);
 			return mb_substr($str, $start, $length, '8bit');
 		}