PHP Classes

File: system/core/compat/hash.php

Recommend this page to a friend!
  Classes of Kishor Mali   PHP User Feedback System   system/core/compat/hash.php   Download  
File: system/core/compat/hash.php
Role: Auxiliary script
Content type: text/plain
Description: Auxiliary script
Class: PHP User Feedback System
Application to record feedback from customers
Author: By
Last change:
Date: 4 years ago
Size: 6,856 bytes
 

Contents

Class file image Download
<?php
/**
 * CodeIgniter
 *
 * An open source application development framework for PHP
 *
 * This content is released under the MIT License (MIT)
 *
 * Copyright (c) 2014 - 2017, 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 - 2017, 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');

/**
 * PHP ext/hash compatibility package
 *
 * @package CodeIgniter
 * @subpackage CodeIgniter
 * @category Compatibility
 * @author Andrey Andreev
 * @link https://codeigniter.com/user_guide/
 * @link http://php.net/hash
 */

// ------------------------------------------------------------------------

if (is_php('5.6'))
{
    return;
}

// ------------------------------------------------------------------------

if ( ! function_exists('hash_equals'))
{
   
/**
     * hash_equals()
     *
     * @link http://php.net/hash_equals
     * @param string $known_string
     * @param string $user_string
     * @return bool
     */
   
function hash_equals($known_string, $user_string)
    {
        if ( !
is_string($known_string))
        {
           
trigger_error('hash_equals(): Expected known_string to be a string, '.strtolower(gettype($known_string)).' given', E_USER_WARNING);
            return
FALSE;
        }
        elseif ( !
is_string($user_string))
        {
           
trigger_error('hash_equals(): Expected user_string to be a string, '.strtolower(gettype($user_string)).' given', E_USER_WARNING);
            return
FALSE;
        }
        elseif ((
$length = strlen($known_string)) !== strlen($user_string))
        {
            return
FALSE;
        }

       
$diff = 0;
        for (
$i = 0; $i < $length; $i++)
        {
           
$diff |= ord($known_string[$i]) ^ ord($user_string[$i]);
        }

        return (
$diff === 0);
    }
}

// ------------------------------------------------------------------------

if (is_php('5.5'))
{
    return;
}

// ------------------------------------------------------------------------

if ( ! function_exists('hash_pbkdf2'))
{
   
/**
     * hash_pbkdf2()
     *
     * @link http://php.net/hash_pbkdf2
     * @param string $algo
     * @param string $password
     * @param string $salt
     * @param int $iterations
     * @param int $length
     * @param bool $raw_output
     * @return string
     */
   
function hash_pbkdf2($algo, $password, $salt, $iterations, $length = 0, $raw_output = FALSE)
    {
        if ( !
in_array(strtolower($algo), hash_algos(), TRUE))
        {
           
trigger_error('hash_pbkdf2(): Unknown hashing algorithm: '.$algo, E_USER_WARNING);
            return
FALSE;
        }

        if ((
$type = gettype($iterations)) !== 'integer')
        {
            if (
$type === 'object' && method_exists($iterations, '__toString'))
            {
               
$iterations = (string) $iterations;
            }

            if (
is_string($iterations) && is_numeric($iterations))
            {
               
$iterations = (int) $iterations;
            }
            else
            {
               
trigger_error('hash_pbkdf2() expects parameter 4 to be long, '.$type.' given', E_USER_WARNING);
                return
NULL;
            }
        }

        if (
$iterations < 1)
        {
           
trigger_error('hash_pbkdf2(): Iterations must be a positive integer: '.$iterations, E_USER_WARNING);
            return
FALSE;
        }

        if ((
$type = gettype($length)) !== 'integer')
        {
            if (
$type === 'object' && method_exists($length, '__toString'))
            {
               
$length = (string) $length;
            }

            if (
is_string($length) && is_numeric($length))
            {
               
$length = (int) $length;
            }
            else
            {
               
trigger_error('hash_pbkdf2() expects parameter 5 to be long, '.$type.' given', E_USER_WARNING);
                return
NULL;
            }
        }

        if (
$length < 0)
        {
           
trigger_error('hash_pbkdf2(): Length must be greater than or equal to 0: '.$length, E_USER_WARNING);
            return
FALSE;
        }

       
$hash_length = defined('MB_OVERLOAD_STRING')
            ?
mb_strlen(hash($algo, NULL, TRUE), '8bit')
            :
strlen(hash($algo, NULL, TRUE));
        empty(
$length) && $length = $hash_length;

       
// Pre-hash password inputs longer than the algorithm's block size
        // (i.e. prepare HMAC key) to mitigate potential DoS attacks.
       
static $block_sizes;
        empty(
$block_sizes) && $block_sizes = array(
           
'gost' => 32,
           
'haval128,3' => 128,
           
'haval160,3' => 128,
           
'haval192,3' => 128,
           
'haval224,3' => 128,
           
'haval256,3' => 128,
           
'haval128,4' => 128,
           
'haval160,4' => 128,
           
'haval192,4' => 128,
           
'haval224,4' => 128,
           
'haval256,4' => 128,
           
'haval128,5' => 128,
           
'haval160,5' => 128,
           
'haval192,5' => 128,
           
'haval224,5' => 128,
           
'haval256,5' => 128,
           
'md2' => 16,
           
'md4' => 64,
           
'md5' => 64,
           
'ripemd128' => 64,
           
'ripemd160' => 64,
           
'ripemd256' => 64,
           
'ripemd320' => 64,
           
'salsa10' => 64,
           
'salsa20' => 64,
           
'sha1' => 64,
           
'sha224' => 64,
           
'sha256' => 64,
           
'sha384' => 128,
           
'sha512' => 128,
           
'snefru' => 32,
           
'snefru256' => 32,
           
'tiger128,3' => 64,
           
'tiger160,3' => 64,
           
'tiger192,3' => 64,
           
'tiger128,4' => 64,
           
'tiger160,4' => 64,
           
'tiger192,4' => 64,
           
'whirlpool' => 64
       
);

        if (isset(
$block_sizes[$algo], $password[$block_sizes[$algo]]))
        {
           
$password = hash($algo, $password, TRUE);
        }

       
$hash = '';
       
// Note: Blocks are NOT 0-indexed
       
for ($bc = (int) ceil($length / $hash_length), $bi = 1; $bi <= $bc; $bi++)
        {
           
$key = $derived_key = hash_hmac($algo, $salt.pack('N', $bi), $password, TRUE);
            for (
$i = 1; $i < $iterations; $i++)
            {
               
$derived_key ^= $key = hash_hmac($algo, $key, $password, TRUE);
            }

           
$hash .= $derived_key;
        }

       
// This is not RFC-compatible, but we're aiming for natural PHP compatibility
       
if ( ! $raw_output)
        {
           
$hash = bin2hex($hash);
        }

        return
defined('MB_OVERLOAD_STRING')
            ?
mb_substr($hash, 0, $length, '8bit')
            :
substr($hash, 0, $length);
    }
}