<?php
define('PASSWORD_STD_DES', 'std_des'); define('PASSWORD_EXT_DES', 'ext_des'); define('PASSWORD_MD5', 'md5'); define('PASSWORD_BLOWFISH', 'blowfish'); define('PASSWORD_SHA256', 'sha256'); define('PASSWORD_SHA512', 'sha512');
function des_compat_salt($salt_len) {
$characters = './0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz';
$salt = '';
for ($i=0; $i<$salt_len; $i++) {
$salt .= $characters[rand(0, strlen($characters)-1)]; // TODO: use rand() to make the RND cryptographical secure }
return $salt;
}
function base64_int_encode($num) {
// https://stackoverflow.com/questions/15534982/which-iteration-rules-apply-on-crypt-using-crypt-ext-des
$alphabet_raw='./0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz';
while($num) {
$rem=$num % $base;
$num=(int)($num / $base);
$arr[]=$alphabet[$rem];
}
return str_pad($string, 4, '.', STR_PAD_RIGHT
); }
/** This function extends password_hash() with the algorithms supported by crypt().
* The result can be verified using password_verify().
* @param string $password to be hashed
* @param mixed $algo algorithm
* @param array $options options for the hashing algorithm
* @return string Crypt compatible password hash
*/
function password_hash_ex
($password, $algo, $options=array()) { if (($algo === PASSWORD_STD_DES
) && defined('CRYPT_STD_DES')) { // Standard DES-based hash with a two character salt from the alphabet "./0-9A-Za-z". Using invalid characters in the salt will cause crypt() to fail.
$salt = des_compat_salt(2);
return crypt($password, $salt); } else if (($algo === PASSWORD_EXT_DES
) && defined('CRYPT_EXT_DES')) { // Extended DES-based hash. The "salt" is a 9-character string consisting of an underscore followed by 4 characters of iteration count and 4 characters of salt. Each of these 4-character strings encode 24 bits, least significant character first. The values 0 to 63 are encoded as ./0-9A-Za-z. Using invalid characters in the salt will cause crypt() to fail.
$iterations = isset($options['iterations']) ?
$options['iterations'] : 725; $salt = '_' . base64_int_encode($iterations) . des_compat_salt(4);
return crypt($password, $salt); } else if (($algo === PASSWORD_MD5
) && defined('CRYPT_MD5')) { // MD5 hashing with a twelve character salt starting with $1$
$salt = '$1$'.des_compat_salt(12).'$';
return crypt($password, $salt); } else if (($algo === PASSWORD_BLOWFISH
) && defined('CRYPT_BLOWFISH')) { // Blowfish hashing with a salt as follows: "$2a$", "$2x$" or "$2y$", a two digit cost parameter, "$", and 22 characters from the alphabet "./0-9A-Za-z". Using characters outside of this range in the salt will cause crypt() to return a zero-length string. The two digit cost parameter is the base-2 logarithm of the iteration count for the underlying Blowfish-based hashing algorithm and must be in range 04-31, values outside this range will cause crypt() to fail. "$2x$" hashes are potentially weak; "$2a$" hashes are compatible and mitigate this weakness. For new hashes, "$2y$" should be used.
$algo = '$2y$'; // most secure
$cost = isset($options['cost']) ?
$options['cost'] : 10; $salt = $algo.str_pad($cost,2,'0',STR_PAD_LEFT
).'$'.des_compat_salt
(22).'$'; return crypt($password, $salt); } else if (($algo === PASSWORD_SHA256
) && defined('CRYPT_SHA256')) { // SHA-256 hash with a sixteen character salt prefixed with $5$. If the salt string starts with 'rounds=<N>$', the numeric value of N is used to indicate how many times the hashing loop should be executed, much like the cost parameter on Blowfish. The default number of rounds is 5000, there is a minimum of 1000 and a maximum of 999,999,999. Any selection of N outside this range will be truncated to the nearest limit.
$algo = '$5$';
$rounds = isset($options['rounds']) ?
$options['rounds'] : 5000; $salt = $algo.'rounds='.$rounds.'$'.des_compat_salt(16).'$';
return crypt($password, $salt); } else if (($algo === PASSWORD_SHA512
) && defined('CRYPT_SHA512')) { // SHA-512 hash with a sixteen character salt prefixed with $6$. If the salt string starts with 'rounds=<N>$', the numeric value of N is used to indicate how many times the hashing loop should be executed, much like the cost parameter on Blowfish. The default number of rounds is 5000, there is a minimum of 1000 and a maximum of 999,999,999. Any selection of N outside this range will be truncated to the nearest limit.
$algo = '$6$';
$rounds = isset($options['rounds']) ?
$options['rounds'] : 5000; $salt = $algo.'rounds='.$rounds.'$'.des_compat_salt(16).'$';
return crypt($password, $salt); } else {
// $algo === PASSWORD_DEFAULT
// $algo === PASSWORD_BCRYPT
// $algo === PASSWORD_ARGON2I
// $algo === PASSWORD_ARGON2ID
return password_hash($password, $algo, $options);
}
}