这些今天的“最佳”解决方案是什么?
这似乎是一个不错的选择: https ://defuse.ca/php-pbkdf2.htm
但是,升级到 PHP5.5 并使用它怎么样? http://php.net/manual/en/function.hash-pbkdf2.php
很好奇为什么 PHP 网站声明:
注意 PBKDF2 方法可用于存储密码的散列(NIST 批准用于该用途)。但是,应该注意 CRYPT_BLOWFISH 更适合密码存储,应该通过 crypt() 来代替。
对于低于 5.5 的 PHP 版本,使用 defuse.ca 解决方案是否公平,然后在升级到 PHP5.5 后将其切换出来?
/*
* 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));
}
这是 defuse.ca 的当前解决方案,将这个函数重命名为 hash_pbkdf2() 是否公平,并且在升级到 PHP5.5 后过渡会很顺利?