Auth Library

<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
 
/**
 *	Auth Class
 *
 *	Simple authentication library for my blog
 *
 *	@author 	Mark A. LaDoux
 *	@copyright	Copyright © 2012 Mark LaDoux
 *	@link		http://markladoux.com/
 *	@version	1.0.0
 */
 
class Auth
{
	/**
	 * 	Internal Variables
	 *
	 *	@param	object	$ci			CodeIgniter instance
	 *	@param	integer	$rounds		number of iterations to process the hash
	 *	@param	string	$user_table	table to use for user data
	 *	@param	array	$errors		array of errors
	 */
 
	protected 			$ci			= null;
	protected	static	$rounds		= null;
	protected	static	$user_table	= null;
	protected	static	$errors		= array();
 
	/**
	 *	__construct
	 *
	 *	prepares the library for first use
	 *
	 *	@access	public
	 *	@since	1.0.0
	 *	@return	void
	 */
 
	public function __construct()
	{
		// get CodeIgniter Instance
		$this->ci 			=&	get_instance();
 
		// load required libraries
		$this->ci->load->library('database');
		$this->ci->load->library('session');
 
		// get config settings
		self::$rounds		=	$this->ci->config->item('auth_rounds');
		self::$user_table	=	$this->ci->config->item('auth_user_table');
 
		// run a couple tests
		if(self::$rounds < 4 || self::$rounds > 32) self::$rounds = 8;
		if(self::$user_table === false) self::$user_table = 'users';
	}
 
	/**
	 *	generate_hash
	 *
	 *	generates a random password hash
	 *
	 *	@access	protected
	 *	@since	1.0.0
	 *	@param	string		$password	password to hash
	 *	@return	string					hash of $password
	 */
 
	protected function _generate_hash($password)
	{
		// generate a salt
		$lowercase		= str_shuffle('abcdefghijklmnopqrstuvwxyz');
		$uppercase		= str_shuffle('ABCDEFGHIJKLMNOPQRSTUVWXYZ');
		$other			= str_shuffle('./');
		$legal_chars	= str_shuffle($lowercase.$uppercase.$other);
		$salt			= '';
 
		for($i = 0; $i < 22; $i++)
		{
			$salt			.=	$legal_chars[mt_rand(0,63)]; 
		}
 
		// format salt
		$salt	= sprintf('$2a$%02d$', $this->rounds).str_shuffle($salt);
 
		// return hash
		return crypt($password, $salt);
	}
 
	/**
	 *	_verify_hash
	 *
	 *	tests to see if password matches hash evaluation
	 *
	 *	@access	protected
	 *	@since	1.0.0
	 *	@param	string		$password		password to check
	 *	@param	string		$stored_hash	hash to check password against
	 *	@return	bool						true if passes, else false
	 */
 
	protected function _verify_password($password, $stored_hash)
	{
		$test = (crypt($password, $stored_hash) == $stored_hash) ? true : false;
		return $test;
	}
 
	/**
	 *	_check_email
	 *
	 *	tests if email is valid and available for registration
	 *
	 *	@access	protected
	 *	@since	1.0.0
	 *	@param	string		$email	email address to check
	 *	@return	void
	 */
 
	protected function _check_email($email)
	{
		$valid_email = filter_var($email, FILTER_VALIDATE_EMAIL);
		if($valid_email)
		{
			$this->ci->db->where('email', $email);
			$this->ci->db->limit(1);
			$query	= $this->db->get(self::$user_table);
			$in_use	= ($query->num_rows() > 0) ? true : false;
		}
 
		if(! $valid_email)
		{
			self::$errors['email']	= 'invalid';
		}
		elseif($in_use)
		{
			self::$errors['email']	= 'unavailable';
		}
	}
 
	/**
	 *	_check_username
	 *
	 *	tests if username is available for registration
	 *
	 *	@access	protected
	 *	@since	1.0.0
	 *	@param	string		$username	username to check
	 *	@return	void
	 */
 
	protected function _check_username($username)
	{
		$this->ci->db->where('username', $username);
		$this->ci->db->limit(1);
		$query	= $this->ci->db->get(self::$user_table);
		if($query->num_rows() > 0)
		{
			self::$errors['username']	= 'unavailable';
		}
	}
 
	/**
	 *	login
	 *
	 *	checks a users credentials and logs him in to the system.
	 *
	 *	@access	public
	 *	@since	1.0.0
	 *	@param	string	$username	user to log in
	 *	@param	string	$password	user's password
	 *	@return	bool				true if logged in, else false
	 */
 
	public function login($username, $password)
	{
		$this->db->where('username', $username);
		$this->db->limit(1);
		$query	= $this->db->get(self::$user_table);
		if($query->num_rows() < 1)
		{
			$this->ci->session->set_flashdata('login_error', 'invalid_username');
			return false;
		}
		$data	= $query->fetch_assoc();
		$valid_password = $this->_verify_password($password, $data['password']);
		if($valid_password)
		{
			// remove password from data array
			unset($data['password']);
 
			// set the session
			$data['logged_in']	= true;
			$this->ci->session->set_userdata($row);
			return true;
		}
		else
		{
			$this->ci->session->set_flashdata('login_error', 'invalid_password');
			return false;
		}
	}
 
	/**
	 *	logout
	 *	
	 *	logs user off site.
	 *
	 *	@access	public
	 *	@since	1.0.0
	 *	@return	void
	 */
 
	public function logout()
	{
		$this->ci->session->sess_destroy();
	}
 
	/**
	 *	create
	 *
	 *	creates a new user in the database
	 *
	 *	@access	public
	 *	@since	1.0.0
	 *	@param	string	$username	username to create
	 *	@param	string	$email		email address of $username
	 *	@param	string	$password	password for $username
	 */
 
	public function create($username, $email, $password)
	{
		$this->_check_username($username);
		$this->_check_email($email);
		if(isset(self::$errrors['username']) || isset(self::$errors['email']))
		{
			$this->ci->session->set_flashdata(self::$errors);
			return false;
		}
 
		$password_hash = $this->_generate_hash($password);
 
		$data['username']	= $username;
		$data['password']	= $password_hash;
		$data['email']		= $email;
 
		$this->ci->db->insert(self::$user_table, $data);
		return true;
	}
 
	/**
	 *	delete
	 *
	 *	deletes a user from the database
	 *
	 *	@access	public
	 *	@since	1.0.0
	 *	@param	string	$username	username to remove
	 *	@return	void
	 */
 
	public function delete($username)
	{
		$this->ci->db->delete(self::$user_table, array('username' => $username));
	}
 
	/**
	 *	set_password
	 *
	 *	changes the password of an existing user
	 *
	 *	@access	public
	 *	@since	1.0.0
	 *	@param	string	$username	username to edit
	 *	@param	string	$password	new password to set
	 *	@return	void
	 */
 
	public function set_password($username, $password)
	{
		$password	= $this->_generate_hash($password);
		$this->ci->db->where('username', $username);
		$this->ci->db->update(self::$user_table, array('password' => $password));
	}
 
	/**
	 *	set_email
	 *
	 *	changes the email of an existing user
	 *
	 *	@access	public
	 *	@since	1.0.0
	 *	@param	string	$username	username to edit
	 *	@param	string	$email		new email address to set
	 *	@return	void
	 */
 
	public function set_email($username, $email)
	{
		$this->_check_email($email);
		if(isset(self::$errors['email']))
		{
			$this->ci->session->set_flashdata(self::$errors);
		}
		else
		{
			$this->ci->db->where('username', $username);
			$this->ci->db->update(self::$user_table, array('email' => $email));
		}
	}
}