Ochiq kalitli kriptografiya

function korsat(string $nom, string $qiymat): void
{
    printf("%-16s %s%s", $nom . ':', $qiymat, PHP_EOL);
}

// Simmetrik kalitlar: har juftlik uchun alohida kalit kerak
printf("%-14s %s%s", 'Ishtirokchi', 'Kerakli kalitlar', PHP_EOL);
echo str_repeat('-', 34), PHP_EOL;

foreach ([2, 5, 10, 100, 1000] as $n) {
    printf('%-14d %s%s', $n,
        number_format($n * ($n - 1) / 2, 0, '.', ' '), PHP_EOL);
}

echo PHP_EOL, 'Ochiq kalitli tizimda: har kishiga BITTA juft', PHP_EOL;

// DIQQAT: bu kalit faqat DARSLIK UCHUN yaratilgan va ochiq e'lon qilingan.
// Uni hech qachon real tizimda ishlatmang.
const DEMO_MAXFIY = <<<'PEM'
-----BEGIN PRIVATE KEY-----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-----END PRIVATE KEY-----
PEM;

const DEMO_OCHIQ = <<<'PEM'
-----BEGIN PUBLIC KEY-----
MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEAwDGgk+vGrIp2af2mG644
jR4SkmxVzi6V6XMJWWEno0qFbksi3IVg+ecBPz+8y7fmSgd+M66cBTT36iAiJ76+
aNlcKFEN9F7Bjjz+vNLHp3etRSlLYqmae5DBtUf+ekyV0/i67f5bOZERoiBX3FmN
CoWkOvvPJzF+1gL+NIr0J4YbhU6P4SyDK23S2KaCToDcwuICgLsoS1SH4NslRcis
udDLXwWtoL+SZs9bPRQFt/KUUCE4S3dkxKjLcbagepJN2e1vpc2Q6778NFxgitj+
fIwUcfbrTQAW+MMjFhmG612WPW5LeuBsfoqE5WZfKxkLjSzNDE9QzQqLIYBG+Txh
4wIDAQAB
-----END PUBLIC KEY-----
PEM;

$maxfiy = openssl_pkey_get_private(DEMO_MAXFIY);
$tafsilot = openssl_pkey_get_details($maxfiy);

korsat('turi', ['rsa', 'dsa', 'dh', 'ec'][$tafsilot['type']] ?? 'nomalum');
korsat('uzunlik', $tafsilot['bits'] . ' bit');
korsat('modul (n)', substr(bin2hex($tafsilot['rsa']['n']), 0, 40) . '...');
korsat('daraja (e)', bin2hex($tafsilot['rsa']['e']));

// Ochiq kalitni maxfiy kalitdan chiqarish MUMKIN
$tozala = static fn(string $pem): string => preg_replace('/\s+/', '', $pem);

korsat('mos keladimi',
    $tozala($tafsilot['key']) === $tozala(DEMO_OCHIQ) ? 'ha' : 'yoq');

$maxfiy = openssl_pkey_get_private(DEMO_MAXFIY);

$sir = 'Uchrashuv soat 15:00 da';

// Shifrlash - OCHIQ kalit bilan (har kim qila oladi)
$ok = openssl_public_encrypt($sir, $shifr, DEMO_OCHIQ,
    OPENSSL_PKCS1_OAEP_PADDING);

var_dump($ok);
korsat('shifr uzunligi', strlen($shifr) . ' bayt');

// Ochish - MAXFIY kalit bilan (faqat egasi)
$ok = openssl_private_decrypt($shifr, $ochiq, $maxfiy,
    OPENSSL_PKCS1_OAEP_PADDING);

var_dump($ok);
korsat('ochilgan', $ochiq);

// Ochiq kalit bilan ochib bo'lmaydi
$natija = @openssl_public_decrypt($shifr, $x, DEMO_OCHIQ,
    OPENSSL_PKCS1_OAEP_PADDING);
korsat('ochiq kalit bilan', var_export($natija, true));

$maxfiy = openssl_pkey_get_private(DEMO_MAXFIY);
$kalitBayt = openssl_pkey_get_details($maxfiy)['bits'] / 8;

korsat('kalit', $kalitBayt . ' bayt');
korsat('OAEP xarajati', '42 bayt (SHA-1 bilan)');
korsat('eng koto matn', ($kalitBayt - 42) . ' bayt');

echo PHP_EOL;

foreach ([100, 200, 214, 215, 500] as $uz) {
    $matn = str_repeat('x', $uz);
    $ok = @openssl_public_encrypt($matn, $s, DEMO_OCHIQ,
        OPENSSL_PKCS1_OAEP_PADDING);
    printf('%3d bayt: %s%s', $uz, $ok ? 'shifrlandi' : 'RAD ETILDI', PHP_EOL);
}

final class GibridKonvert
{
    public function yop(string $matn, string $ochiqKalit): array
    {
        // 1. Bir martalik sessiya kaliti
        $sessiya = random_bytes(32);
        $nonce = random_bytes(12);
        $teg = '';

        // 2. Ma'lumotni AES-GCM bilan shifrlaymiz
        $shifr = openssl_encrypt($matn, 'aes-256-gcm', $sessiya,
            OPENSSL_RAW_DATA, $nonce, $teg);

        // 3. Sessiya kalitini RSA bilan shifrlaymiz
        if (!openssl_public_encrypt($sessiya, $shifrKalit, $ochiqKalit,
                OPENSSL_PKCS1_OAEP_PADDING)) {
            throw new RuntimeException('kalitni shifrlab bolmadi');
        }

        return [
            'kalit' => base64_encode($shifrKalit),
            'nonce' => base64_encode($nonce),
            'teg' => base64_encode($teg),
            'malumot' => base64_encode($shifr),
        ];
    }

    public function och(array $paket, string $maxfiyKalit): string
    {
        $maxfiy = openssl_pkey_get_private($maxfiyKalit);
        if ($maxfiy === false) {
            throw new RuntimeException('maxfiy kalit oqilmadi');
        }

        // 1. Sessiya kalitini ochamiz
        if (!openssl_private_decrypt(base64_decode($paket['kalit']),
                $sessiya, $maxfiy, OPENSSL_PKCS1_OAEP_PADDING)) {
            throw new RuntimeException('sessiya kaliti ochilmadi');
        }

        // 2. Ma'lumotni ochamiz
        $matn = openssl_decrypt(base64_decode($paket['malumot']),
            'aes-256-gcm', $sessiya, OPENSSL_RAW_DATA,
            base64_decode($paket['nonce']), base64_decode($paket['teg']));

        if ($matn === false) {
            throw new RuntimeException('butunlik tekshiruvi otmadi');
        }

        return $matn;
    }
}

$gibrid = new GibridKonvert();

// Katta ma'lumot - RSA yolg'iz uddalay olmaydi
$katta = str_repeat('Maxfiy hisobot qatori. ', 500);
echo 'malumot hajmi: ', strlen($katta), ' bayt', PHP_EOL;

$paket = $gibrid->yop($katta, DEMO_OCHIQ);

foreach ($paket as $nom => $qiymat) {
    printf('%-9s %d belgi%s', $nom . ':', strlen($qiymat), PHP_EOL);
}

$ochilgan = $gibrid->och($paket, DEMO_MAXFIY);
echo PHP_EOL, 'ochildi va mos keldi: ',
    $ochilgan === $katta ? 'ha' : 'yoq', PHP_EOL;

$gibrid = new GibridKonvert();
$paket = $gibrid->yop('Maxfiy xabar', DEMO_OCHIQ);

$sinovlar = [
    'malumot buzildi' => static function () use ($gibrid, $paket) {
        $p = $paket;
        $x = base64_decode($p['malumot']);
        $x[0] = chr(ord($x[0]) ^ 0xff);
        $p['malumot'] = base64_encode($x);
        return $gibrid->och($p, DEMO_MAXFIY);
    },
    'teg buzildi' => static function () use ($gibrid, $paket) {
        $p = $paket;
        $x = base64_decode($p['teg']);
        $x[0] = chr(ord($x[0]) ^ 0xff);
        $p['teg'] = base64_encode($x);
        return $gibrid->och($p, DEMO_MAXFIY);
    },
    'kalit buzildi' => static function () use ($gibrid, $paket) {
        $p = $paket;
        $x = base64_decode($p['kalit']);
        $x[0] = chr(ord($x[0]) ^ 0xff);
        $p['kalit'] = base64_encode($x);
        return $gibrid->och($p, DEMO_MAXFIY);
    },
];

foreach ($sinovlar as $nom => $sinov) {
    try {
        $sinov();
        printf('%-18s OTDI - KUTILMAGAN%s', $nom, PHP_EOL);
    } catch (RuntimeException $x) {
        printf('%-18s RAD: %s%s', $nom, $x->getMessage(), PHP_EOL);
    }
}

$sir = 'test';

// OAEP - to'g'ri tanlov
$ok1 = openssl_public_encrypt($sir, $s1, DEMO_OCHIQ,
    OPENSSL_PKCS1_OAEP_PADDING);

// PKCS#1 v1.5 - eskirgan
$ok2 = openssl_public_encrypt($sir, $s2, DEMO_OCHIQ,
    OPENSSL_PKCS1_PADDING);

// To'ldirishsiz - juda xavfli
$ok3 = @openssl_public_encrypt(str_pad($sir, 256, "\x00", STR_PAD_LEFT),
    $s3, DEMO_OCHIQ, OPENSSL_NO_PADDING);

printf("%-22s %s%s", 'OAEP:', $ok1 ? 'ishladi' : 'xato', PHP_EOL);
printf("%-22s %s%s", 'PKCS#1 v1.5:', $ok2 ? 'ishladi' : 'xato', PHP_EOL);
printf("%-22s %s%s", 'toldirishsiz:', $ok3 ? 'ishladi' : 'xato', PHP_EOL);

// Bir xil xavfsizlik darajasi uchun kerakli kalit uzunligi
$jadval = [
    ['80 bit', '1024', '160', 'eskirgan'],
    ['112 bit', '2048', '224', 'minimal'],
    ['128 bit', '3072', '256', 'tavsiya etiladi'],
    ['192 bit', '7680', '384', 'yuqori'],
    ['256 bit', '15360', '521', 'juda yuqori'],
];

printf("%-10s %-10s %-8s %s%s", 'Xavfsizlik', 'RSA bit', 'EC bit',
    'Baho', PHP_EOL);
echo str_repeat('-', 48), PHP_EOL;
foreach ($jadval as $q) {
    printf("%-10s %-10s %-8s %s%s", ...[...$q, PHP_EOL]);
}