<?php
function test_native() {
$st = hrtime(true);
$h = hash_pbkdf2('sha256', 'password', 'salt', 100000);
$et = hrtime(true);
return [$h, $et - $st];
}
function test_emulated() {
$st = hrtime(true);
$K = str_pad('password', 64, "\0");
$K ^= str_repeat("\x36", 64);
$ictx = hash_init('sha256');
hash_update($ictx, $K);
$K ^= str_repeat("\x6a", 64);
$octx = hash_init('sha256');
hash_update($octx, $K);
$DK = str_repeat("\0", 32);
$prev = "salt\0\0\0\1";
for ($j = 0; $j < 100000; ++$j) {
$ctx = hash_copy($ictx);
hash_update($ctx, $prev);
$temp = hash_final($ctx, true);
$ctx = hash_copy($octx);
hash_update($ctx, $temp);
$prev = hash_final($ctx, true);
$DK ^= $prev;
}
$h = bin2hex($DK);
$et = hrtime(true);
return [$h, $et - $st];
}
$nr = test_native();
$er = test_emulated();
var_dump($nr[0]);
var_dump($er[0]);
var_dump($nr[1] <= $er[1]);
preferences:
39.15 ms | 402 KiB | 5 Q