如何安全的存储用户密码？(中)代码篇

PHP PBKDF2 密码hash代码

<?php

* Password Hashing With PBKDF2 (http://crackstation.net/hashing-security.htm).

* Redistribution and use in source and binary forms, with or without

* modification, are permitted provided that the following conditions are met:

* 1. Redistributions of source code must retain the above copyright notice,

* this list of conditions and the following disclaimer.

* 2. Redistributions in binary form must reproduce the above copyright notice,

* this list of conditions and the following disclaimer in the documentation

* and/or other materials provided with the distribution.

* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"

* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE

* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE

* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE

* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR

* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF

* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS

* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN

* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)

* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE

* POSSIBILITY OF SUCH DAMAGE.

// These constants may be changed without breaking existing hashes.

define("PBKDF2_HASH_ALGORITHM", "sha256");

define("PBKDF2_ITERATIONS", 1000);

define("PBKDF2_SALT_BYTE_SIZE", 24);

define("PBKDF2_HASH_BYTE_SIZE", 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_BYTE_SIZE, MCRYPT_DEV_URANDOM));

return PBKDF2_HASH_ALGORITHM . ":" . PBKDF2_ITERATIONS . ":" . $salt . ":" .

base64_encode(pbkdf2(

PBKDF2_HASH_ALGORITHM,

$password,

$salt,

PBKDF2_ITERATIONS,

PBKDF2_HASH_BYTE_SIZE,

true

));

}

function validate_password($password, $correct_hash)

{

$params = explode(":", $correct_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))

trigger_error('PBKDF2 ERROR: Invalid hash algorithm.', E_USER_ERROR);

if($count <= 0 || $key_length <= 0)

trigger_error('PBKDF2 ERROR: Invalid parameters.', E_USER_ERROR);

if (function_exists("hash_pbkdf2")) {

// The output length is in NIBBLES (4-bits) if $raw_output is false!

if (!$raw_output) {

$key_length = $key_length * 2;

}

return hash_pbkdf2($algorithm, $password, $salt, $count, $key_length, $raw_output);

}

$hash_length = strlen(hash($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));

}

java PBKDF2 密码hash代码