PHP - hash_pbkdf2函數

Question

我正在試圖做一個函數來hash這個PHP函數的密碼：http://be.php.net/manual/en/function.hash-pbkdf2.php。

下面是代碼：

$hash_algo = "sha256"; 
$password = "password"; 
$salt = "salt"; 
$iterations = 1; 
$length = 1; 
$raw_output = false; 

$hash = hash_pbkdf2($hash_algo, $password, $salt, $iterations ,$length ,$raw_output); 

echo $hash; 

我得到這個錯誤：致命錯誤：調用未定義功能hash_pbkdf2（）。

函數如何定義？

PS：我的變量的所有值都是爲測試函數而設置的。顯然鹽不會是「鹽」等。

Answer 1

編輯：從PHP 5.5.0開始，此功能現在被捆綁到核心庫中。

---

這個函數在覈心PHP中還沒有（還有）。這是不是很久以前提出，迄今爲止，你只能得到它作爲patch。

您可以改用crypt或hash。 crypt實際上建議在hash_pbkdf2 documentation：

Caution
The PBKDF2 method can be used for hashing passwords for storage (it is NIST approved for that use). However, it should be noted that CRYPT_BLOWFISH is better suited for password storage and should be used instead via crypt() .

Answer 2

你可以在手冊中找到它。

(No version information available, might only be in SVN)

表示此功能不可用。

Answer 3

您CAN使用PBKDF2如果包括自己的功能。只需將this website上的代碼粘貼到您的應用程序中，它就不會更容易。該代碼是公有領域（如該網站所述）。

下面是代碼全：

<?php 
/* 
* Password hashing with PBKDF2. 
* Author: havoc AT defuse.ca 
* www: https://defuse.ca/php-pbkdf2.htm 
*/ 

// These constants may be changed without breaking existing hashes. 
define("PBKDF2_HASH_ALGORITHM", "sha256"); 
define("PBKDF2_ITERATIONS", 1000); 
define("PBKDF2_SALT_BYTES", 24); 
define("PBKDF2_HASH_BYTES", 24); 

define("HASH_SECTIONS", 4); 
define("HASH_ALGORITHM_INDEX", 0); 
define("HASH_ITERATION_INDEX", 1); 
define("HASH_SALT_INDEX", 2); 
define("HASH_PBKDF2_INDEX", 3); 

function create_hash($password) 
{ 
    // format: algorithm:iterations:salt:hash 
    $salt = base64_encode(mcrypt_create_iv(PBKDF2_SALT_BYTES, MCRYPT_DEV_URANDOM)); 
    return PBKDF2_HASH_ALGORITHM . ":" . PBKDF2_ITERATIONS . ":" . $salt . ":" . 
     base64_encode(pbkdf2(
      PBKDF2_HASH_ALGORITHM, 
      $password, 
      $salt, 
      PBKDF2_ITERATIONS, 
      PBKDF2_HASH_BYTES, 
      true 
     )); 
} 

function validate_password($password, $good_hash) 
{ 
    $params = explode(":", $good_hash); 
    if(count($params) < HASH_SECTIONS) 
     return false; 
    $pbkdf2 = base64_decode($params[HASH_PBKDF2_INDEX]); 
    return slow_equals(
     $pbkdf2, 
     pbkdf2(
      $params[HASH_ALGORITHM_INDEX], 
      $password, 
      $params[HASH_SALT_INDEX], 
      (int)$params[HASH_ITERATION_INDEX], 
      strlen($pbkdf2), 
      true 
     ) 
    ); 
} 

// Compares two strings $a and $b in length-constant time. 
function slow_equals($a, $b) 
{ 
    $diff = strlen($a)^strlen($b); 
    for($i = 0; $i < strlen($a) && $i < strlen($b); $i++) 
    { 
     $diff |= ord($a[$i])^ord($b[$i]); 
    } 
    return $diff === 0; 
} 

/* 
* PBKDF2 key derivation function as defined by RSA's PKCS #5: https://www.ietf.org/rfc/rfc2898.txt 
* $algorithm - The hash algorithm to use. Recommended: SHA256 
* $password - The password. 
* $salt - A salt that is unique to the password. 
* $count - Iteration count. Higher is better, but slower. Recommended: At least 1000. 
* $key_length - The length of the derived key in bytes. 
* $raw_output - If true, the key is returned in raw binary format. Hex encoded otherwise. 
* Returns: A $key_length-byte key derived from the password and salt. 
* 
* Test vectors can be found here: https://www.ietf.org/rfc/rfc6070.txt 
* 
* This implementation of PBKDF2 was originally created by https://defuse.ca 
* With improvements by http://www.variations-of-shadow.com 
*/ 
function pbkdf2($algorithm, $password, $salt, $count, $key_length, $raw_output = false) 
{ 
    $algorithm = strtolower($algorithm); 
    if(!in_array($algorithm, hash_algos(), true)) 
     die('PBKDF2 ERROR: Invalid hash algorithm.'); 
    if($count <= 0 || $key_length <= 0) 
     die('PBKDF2 ERROR: Invalid parameters.'); 

    $hash_length = strlen(hash($algorithm, "", true)); 
    $block_count = ceil($key_length/$hash_length); 

    $output = ""; 
    for($i = 1; $i <= $block_count; $i++) { 
     // $i encoded as 4 bytes, big endian. 
     $last = $salt . pack("N", $i); 
     // first iteration 
     $last = $xorsum = hash_hmac($algorithm, $last, $password, true); 
     // perform the other $count - 1 iterations 
     for ($j = 1; $j < $count; $j++) { 
      $xorsum ^= ($last = hash_hmac($algorithm, $last, $password, true)); 
     } 
     $output .= $xorsum; 
    } 

    if($raw_output) 
     return substr($output, 0, $key_length); 
    else 
     return bin2hex(substr($output, 0, $key_length)); 
} 
?> 

如果您需要了解散列，鹽，迭代任何東西，所有其他的東西，this website擁有所有正確的答案。