xlsxhashbf.php

<?php
declare(strict_types=1);

$salt = 'OgybOFzbO8htTTop5nuilg==';
$goal = 'X8fKMgIbDaiNDugq1OHuiTClHruTIL/9J48thPAx2kf3VMNWhnWttE3sLH1LKQ/Yg1UUOZd0Bq6ZLtviWDP2dQ==';
$spinCount = 100000;

//$charlist = 'aejh';
$charList = 'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789-.,åäöÅÄÖ!$%#=@';

echo solve($salt, $goal, $spinCount, $charList, 3);

function solve($salt, $goal, $spinCount, $charList, $maxLength)
{
    $arrayCharlist = mb_str_split($charList);
    fwrite(
        STDERR,
        'Bruteforce 1-' . $maxLength . ' of the ' . count($arrayCharlist) . ' characters ' . $charList . PHP_EOL
    );

    $c = 0;
    $status = static function ($c) {
        fwrite(STDERR, "\r" . $c . ' @ ' . date('Y-m-d H:i:s') . PHP_EOL);
    };
    $status($c);

    foreach (range(1, $maxLength) as $length) {
        foreach (combinations('', $length, $arrayCharlist) as $combination) {
            fwrite(STDERR, '.');
            $c++;
            if ($c % 100 === 0) {
                $status($c);
            }
            $hash = xlsxhash($combination, $salt, $spinCount);
            if ($hash === $goal) {
                $status($c);
                return $combination;
            }
        }
    }
}

function combinations($prefix, $length, $charlist)
{
    if ($length < 2) {
        foreach ($charlist as $char) {
            yield $prefix . $char;
        }
        return;
    }
    foreach ($charlist as $char) {
        yield from combinations($prefix . $char, $length - 1, $charlist);
    }
}

function xlsxhash($utf8Password, $base64Salt, $intSpinCount)
{
    $utf16BEPassword = mb_convert_encoding($utf8Password, 'UTF-16');
    $utf16LEPassword = pack('n*', ...unpack('v*', $utf16BEPassword));
    $rawSalt = base64_decode($base64Salt);
    $data = $rawSalt . $utf16LEPassword;
    for ($i = 0; $i < $intSpinCount; $i++) {
        $int32LE = pack('V', $i);
        $data = hash('sha512', $data, true) . $int32LE;
    }
    $data = hash('sha512', $data, true);
    return base64_encode($data);
}