Eng ko'p uchraydigan xatolar

function korsat(string $nom, string $qiymat): void
{
    printf("%-26s %s%s", $nom . ':', $qiymat, PHP_EOL);
}

$xatolar = [
    [1, 'base64 ni shifrlash deb bilish', 'malumot ochiq'],
    [2, '== yoki === bilan MAC solishtirish', 'vaqt boyicha sizish'],
    [3, 'md5/sha1 ishlatish', 'toqnashuv topiladi'],
    [4, 'parolni sha256 bilan saqlash', 'lugat hujumi tez'],
    [5, 'hash($sir . $matn) bilan imzolash', 'uzunlikni kengaytirish'],
    [6, 'paroldan HKDF bilan kalit olish', 'juda tez - himoya yoq'],
    [7, 'ECB rejimi', 'naqsh korinadi'],
    [8, 'AEAD siz shifrlash', 'ozgartirish sezilmaydi'],
    [9, 'nonce ni takrorlash', 'shifr butunlay ochiladi'],
    [10, 'PKCS#1 v1.5 bilan shifrlash', 'Bleichenbacher hujumi'],
    [11, 'openssl_verify natijasini === 1 siz', '-1 rost hisoblanadi'],
    [12, 'DH natijasini togridan-togri kalit qilish', 'bir tekis emas'],
    [13, 'sertifikat tekshiruvini ochirish', 'MITM ga toliq ochiq'],
    [14, 'TLS 1.0/1.1 ni yoqib qoldirish', 'eskirgan shifrlar'],
    [15, 'token uchun mt_rand/uniqid', 'taxmin qilinadi'],
    [16, 'hamma narsani deterministik shifrlash', 'chastota tahlili'],
    [17, 'JWT alg ni tokendan olish', 'alg=none, chalkashlik'],
    [18, 'kalitni kodda saqlash', 'git tarixida qoladi'],
];

printf("%-4s %-42s %s%s", "BO'LIM", 'XATO', 'OQIBATI', PHP_EOL);
echo str_repeat('-', 82), PHP_EOL;
foreach ($xatolar as $x) {
    printf("%-6d %-42s %s%s", ...[...$x, PHP_EOL]);
}

$kalit = hex2bin(str_repeat('aa', 32));
$nonce = hex2bin(str_repeat('bb', 12));
$teg = '';

$shifr = openssl_encrypt('Maxfiy', 'aes-256-gcm', $kalit,
    OPENSSL_RAW_DATA, $nonce, $teg);

// Buzilgan ma'lumot keldi
$buzuq = $shifr;
$buzuq[0] = chr(ord($buzuq[0]) ^ 0xff);

// XATO: natijani tekshirmasdan ishlatish
$natija = openssl_decrypt($buzuq, 'aes-256-gcm', $kalit,
    OPENSSL_RAW_DATA, $nonce, $teg);

korsat('qaytgan qiymat', var_export($natija, true));
korsat('turi', gettype($natija));

// Endi u satr sifatida ishlatiladi
$foydalanuvchi = (string) $natija;
korsat('satrga aylantirilgan', "'" . $foydalanuvchi . "'");
korsat('bosh satr bilan solishtirish',
    $foydalanuvchi === '' ? 'TENG - xavfli' : 'teng emas');

$kalit = hex2bin(str_repeat('cc', 32));

// XATO: shifrlash uchun ham, imzolash uchun ham bir xil kalit
$nonce = hex2bin(str_repeat('01', 12));
$teg = '';
$shifr = openssl_encrypt('malumot', 'aes-256-gcm', $kalit,
    OPENSSL_RAW_DATA, $nonce, $teg);
$mac = hash_hmac('sha256', $shifr, $kalit);

korsat('xato usul', 'bitta kalit - ikki maqsad');

// TO'G'RI: bitta asosiy kalitdan ikkita ajratilgan kalit
$shifrKaliti = hash_hkdf('sha256', $kalit, 32, 'shifrlash');
$macKaliti = hash_hkdf('sha256', $kalit, 32, 'imzolash');

korsat('shifr kaliti', substr(bin2hex($shifrKaliti), 0, 24) . '...');
korsat('mac kaliti', substr(bin2hex($macKaliti), 0, 24) . '...');
korsat('bir xilmi', hash_equals($shifrKaliti, $macKaliti) ? 'HA' : 'yoq');

$shifrKaliti = hex2bin(str_repeat('11', 32));
$macKaliti = hex2bin(str_repeat('22', 32));
$iv = hex2bin(str_repeat('33', 16));
$matn = 'rol=user';

// XATO 1: MAC ochiq matn ustidan (MAC-then-encrypt)
$mac1 = hash_hmac('sha256', $matn, $macKaliti, true);
$shifr1 = openssl_encrypt($matn . $mac1, 'aes-256-cbc', $shifrKaliti,
    OPENSSL_RAW_DATA, $iv);

// TO'G'RI: MAC shifrmatn ustidan (encrypt-then-MAC)
$shifr2 = openssl_encrypt($matn, 'aes-256-cbc', $shifrKaliti,
    OPENSSL_RAW_DATA, $iv);
$mac2 = hash_hmac('sha256', $iv . $shifr2, $macKaliti, true);

korsat('xato tartib', 'MAC(ochiq matn), keyin shifrlash');
korsat('togri tartib', 'shifrlash, keyin MAC(IV + shifrmatn)');

// To'g'ri usulda buzilgan ma'lumot OCHILMASDAN rad etiladi
$buzuq = $shifr2;
$buzuq[0] = chr(ord($buzuq[0]) ^ 0xff);
$kutilgan = hash_hmac('sha256', $iv . $buzuq, $macKaliti, true);

korsat('buzilgan malumot',
    hash_equals($mac2, $kutilgan) ? 'QABUL' : 'RAD - ochilmasdan');

// XAVFLI: har xato uchun alohida xabar
function xavfliOch(string $paket, string $kalit): string
{
    if (strlen($paket) < 28) {
        return 'XATO: paket juda qisqa';
    }

    $nonce = substr($paket, 0, 12);
    $teg = substr($paket, 12, 16);
    $shifr = substr($paket, 28);

    $matn = openssl_decrypt($shifr, 'aes-256-gcm', $kalit,
        OPENSSL_RAW_DATA, $nonce, $teg);

    if ($matn === false) {
        return 'XATO: teg mos kelmadi';
    }
    if (!str_starts_with($matn, 'v1:')) {
        return 'XATO: versiya notogri';
    }
    if (json_decode(substr($matn, 3), true) === null) {
        return 'XATO: JSON buzuq';
    }

    return 'OK';
}

// XAVFSIZ: hamma xato uchun bitta xabar
function xavfsizOch(string $paket, string $kalit): string
{
    $umumiyXato = 'XATO: paket yaroqsiz';

    if (strlen($paket) < 28) {
        return $umumiyXato;
    }

    $matn = openssl_decrypt(substr($paket, 28), 'aes-256-gcm', $kalit,
        OPENSSL_RAW_DATA, substr($paket, 0, 12), substr($paket, 12, 16));

    if ($matn === false
        || !str_starts_with($matn, 'v1:')
        || json_decode(substr($matn, 3), true) === null) {
        return $umumiyXato;
    }

    return 'OK';
}

$kalit = hex2bin(str_repeat('dd', 32));
$nonce = hex2bin(str_repeat('01', 12));
$teg = '';

$shifr = openssl_encrypt('v1:{"a":1}', 'aes-256-gcm', $kalit,
    OPENSSL_RAW_DATA, $nonce, $teg);
$yaxshi = $nonce . $teg . $shifr;

$sinovlar = [
    'togri paket' => $yaxshi,
    'qisqa paket' => 'abc',
    'buzilgan teg' => $nonce . str_repeat("\x00", 16) . $shifr,
];

printf("%-16s %-28s %s%s", 'PAKET', 'XAVFLI USUL', 'XAVFSIZ USUL', PHP_EOL);
echo str_repeat('-', 74), PHP_EOL;

foreach ($sinovlar as $nom => $paket) {
    printf("%-16s %-28s %s%s", $nom,
        xavfliOch($paket, $kalit), xavfsizOch($paket, $kalit), PHP_EOL);
}

$maxfiy = 'MAXFIY-TOKEN-12345';

// Foydalanuvchi kiritmasi bilan birga siqib shifrlaymiz
function olcham(string $foydalanuvchiMatni, string $maxfiy): int
{
    // XATO: avval siqish, keyin shifrlash
    return strlen(gzcompress($foydalanuvchiMatni . $maxfiy, 9));
}

// Hujumchi turli taxminlar bilan uzunlikni o'lchaydi
$taxminlar = [
    'AAAAAAAAAAAAAAAAAA' => 'butunlay notogri',
    'MAXFIY-XXXXXXXXXXX' => 'boshi togri',
    'MAXFIY-TOKEN-XXXXX' => 'kopi togri',
    'MAXFIY-TOKEN-12345' => 'TOLIQ TOGRI',
];

printf("%-22s %-18s %s%s", 'TAXMIN', 'IZOH', 'SIQILGAN OLCHAM', PHP_EOL);
echo str_repeat('-', 62), PHP_EOL;

foreach ($taxminlar as $taxmin => $izoh) {
    printf("%-22s %-18s %d bayt%s", $taxmin, $izoh,
        olcham($taxmin, $maxfiy), PHP_EOL);
}

function auditQil(string $kod): array
{
    $qoidalar = [
        'md5/sha1 ishlatilgan' => '/\b(md5|sha1)\s*\(/i',
        'ECB rejimi' => '/[\'"]\w+-ecb[\'"]/i',
        'MAC uchun == yoki ===' => '/hash_hmac\([^)]*\)\s*[=!]==?/',
        'mt_rand/rand token uchun' => '/\b(mt_rand|rand|uniqid)\s*\(/',
        'qattiq yozilgan kalit' => '/[\'"][0-9a-f]{32,}[\'"]/i',
        'tekshiruv ochirilgan' => '/verify_peer\s*=>\s*false/i',
        'PKCS1 v1.5 shifrlash' => '/OPENSSL_PKCS1_PADDING/',
        'toldirishsiz RSA' => '/OPENSSL_NO_PADDING/',
    ];

    $topilgan = [];
    foreach ($qoidalar as $nom => $naqsh) {
        if (preg_match($naqsh, $kod)) {
            $topilgan[] = $nom;
        }
    }

    return $topilgan;
}

$namunalar = [
    'toza kod' => '$x = openssl_encrypt($m, "aes-256-gcm", $k, 0, $n, $t);',
    'md5 parol' => '$xesh = md5($parol);',
    'ecb rejimi' => 'openssl_encrypt($m, "aes-256-ecb", $k);',
    'zaif token' => '$token = uniqid();',
    'tekshiruvsiz' => '["ssl" => ["verify_peer" => false]]',
    'qattiq kalit' => '$k = "' . str_repeat('ab', 16) . '";',
];

foreach ($namunalar as $nom => $kod) {
    $t = auditQil($kod);
    printf('%-14s %s%s', $nom,
        $t === [] ? 'toza' : 'OGOHLANTIRISH: ' . implode('; ', $t), PHP_EOL);
}