Xesh funksiyalari

function xeshKorsat(string $nom, string $qiymat, string $algo = 'sha256'): void
{
    printf("%-22s %s%s", $nom, hash($algo, $qiymat), PHP_EOL);
}

// 1. Aniqlik: bir xil kirish - har doim bir xil chiqish
xeshKorsat('birinchi marta', 'Salom');
xeshKorsat('ikkinchi marta', 'Salom');

// 2. Qat'iy uzunlik: kirish hajmi ahamiyatsiz
$qisqa = hash('sha256', 'a');
$uzun = hash('sha256', str_repeat('a', 1000000));

echo 'bir belgi:    ', strlen($qisqa), ' hex belgi', PHP_EOL;
echo 'million belgi:', strlen($uzun), ' hex belgi', PHP_EOL;

$a = hash('sha256', 'Salom', true);
$b = hash('sha256', 'Talom', true);   // S -> T, bitta harf

echo 'a: ', bin2hex($a), PHP_EOL;
echo 'b: ', bin2hex($b), PHP_EOL;

// nechta bit farq qilgan?
$farq = 0;
for ($i = 0; $i < strlen($a); $i++) {
    $xor = ord($a[$i]) ^ ord($b[$i]);
    $farq += substr_count(decbin($xor), '1');
}

printf('jami bit:     %d%s', strlen($a) * 8, PHP_EOL);
printf('farq qilgan:  %d bit%s', $farq, PHP_EOL);
printf('foiz:         %.1f%%%s', $farq / (strlen($a) * 8) * 100, PHP_EOL);

// Xesh natijasining faqat birinchi 3 baytini olamiz - 24 bit
function qisqaXesh(string $matn): string
{
    return substr(hash('sha256', $matn), 0, 6);
}

$korilgan = [];
$urinish = 0;

while (true) {
    $matn = 'xabar-' . $urinish;
    $x = qisqaXesh($matn);

    if (isset($korilgan[$x])) {
        echo "TO'QNASHUV topildi!", PHP_EOL;
        echo '  1-matn: ', $korilgan[$x], PHP_EOL;
        echo '  2-matn: ', $matn, PHP_EOL;
        echo '  xesh:   ', $x, PHP_EOL;
        echo '  urinish: ', $urinish, PHP_EOL;
        break;
    }

    $korilgan[$x] = $matn;
    $urinish++;
}

// to'liq xeshlar esa butunlay boshqacha
echo PHP_EOL, 'toliq xeshlar:', PHP_EOL;
echo '  ', substr(hash('sha256', $korilgan[$x]), 0, 32), '...', PHP_EOL;
echo '  ', substr(hash('sha256', $matn), 0, 32), '...', PHP_EOL;

$algolar = ['md5', 'sha1', 'sha256', 'sha512', 'sha3-256'];

printf("%-10s %-6s %s%s", 'algoritm', 'bit', 'holati', PHP_EOL);
echo str_repeat('-', 46), PHP_EOL;

$holat = [
    'md5' => 'BUZILGAN - toqnashuv topiladi',
    'sha1' => 'BUZILGAN - toqnashuv topiladi',
    'sha256' => 'ishonchli',
    'sha512' => 'ishonchli',
    'sha3-256' => 'ishonchli',
];

foreach ($algolar as $a) {
    printf("%-10s %-6d %s%s", $a,
        strlen(hash($a, '')) * 4, $holat[$a], PHP_EOL);
}

$fayl = tempnam(sys_get_temp_dir(), 'kr');
file_put_contents($fayl, "hisobot\nsatr 1\nsatr 2\n");

$asl = hash_file('sha256', $fayl);
echo 'asl xesh:  ', substr($asl, 0, 24), '...', PHP_EOL;

// nusxa ko'chirdik
$nusxa = $fayl . '.nusxa';
copy($fayl, $nusxa);
echo 'nusxa mos: ', hash_equals($asl, hash_file('sha256', $nusxa))
    ? 'ha' : 'yoq', PHP_EOL;

// bitta bayt o'zgardi
file_put_contents($nusxa, "hisobot\nsatr 1\nsatr 3\n");
echo 'ozgargach: ', hash_equals($asl, hash_file('sha256', $nusxa))
    ? 'ha' : 'yoq', PHP_EOL;

unlink($fayl);
unlink($nusxa);

$soni = 200000;
$boshlanish = hrtime(true);

for ($i = 0; $i < $soni; $i++) {
    hash('sha256', 'parol' . $i);
}

$sekund = (hrtime(true) - $boshlanish) / 1e9;
$tezlik = $soni / $sekund;

// Aniq raqam mashinaga bog'liq, shuning uchun chegara bilan tekshiramiz
printf('%d ta SHA-256 hisoblandi%s', $soni, PHP_EOL);
printf('bir soniyadan kam vaqtda: %s%s',
    $sekund < 1.0 ? 'ha' : 'yoq', PHP_EOL);
printf('soniyasiga 500 000 dan kop: %s%s',
    $tezlik > 500000 ? 'ha' : 'yoq', PHP_EOL);
echo 'va bu - oddiy noutbuk, PHP da, bitta yadroda', PHP_EOL;

// XATO: sirni oldiga qo'yib xeshlash
$sir = 'maxfiy-kalit';
$malumot = 'foydalanuvchi=oddiy&admin=0';

$notogriImzo = hash('sha256', $sir . $malumot);
echo 'notogri usul: ', substr($notogriImzo, 0, 32), '...', PHP_EOL;

// TO'G'RI: HMAC
$togriImzo = hash_hmac('sha256', $malumot, $sir);
echo 'togri usul:   ', substr($togriImzo, 0, 32), '...', PHP_EOL;