Proven Expertise
Our team brings years of experience in the digital payments industry to provide reliable services.
<?php
namespace Defuse\Crypto;
use Defuse\Crypto\Exception as Ex;
final class KeyOrPassword
{
const PBKDF2_ITERATIONS = 100000;
const SECRET_TYPE_KEY = 1;
const SECRET_TYPE_PASSWORD = 2;
/**
* @var int
*/
private $secret_type = 0;
/**
* @var Key|string
*/
private $secret;
/**
* Initializes an instance of KeyOrPassword from a key.
*
* @param Key $key
*
* @return KeyOrPassword
*/
public static function createFromKey(Key $key)
{
return new KeyOrPassword(self::SECRET_TYPE_KEY, $key);
}
/**
* Initializes an instance of KeyOrPassword from a password.
*
* @param string $password
*
* @return KeyOrPassword
*/
public static function createFromPassword(
#[\SensitiveParameter]
$password
)
{
return new KeyOrPassword(self::SECRET_TYPE_PASSWORD, $password);
}
/**
* Derives authentication and encryption keys from the secret, using a slow
* key derivation function if the secret is a password.
*
* @param string $salt
*
* @throws Ex\CryptoException
* @throws Ex\EnvironmentIsBrokenException
*
* @return DerivedKeys
*/
public function deriveKeys($salt)
{
Core::ensureTrue(
Core::ourStrlen($salt) === Core::SALT_BYTE_SIZE,
'Bad salt.'
);
if ($this->secret_type === self::SECRET_TYPE_KEY) {
Core::ensureTrue($this->secret instanceof Key);
/**
* @psalm-suppress PossiblyInvalidMethodCall
*/
$akey = Core::HKDF(
Core::HASH_FUNCTION_NAME,
$this->secret->getRawBytes(),
Core::KEY_BYTE_SIZE,
Core::AUTHENTICATION_INFO_STRING,
$salt
);
/**
* @psalm-suppress PossiblyInvalidMethodCall
*/
$ekey = Core::HKDF(
Core::HASH_FUNCTION_NAME,
$this->secret->getRawBytes(),
Core::KEY_BYTE_SIZE,
Core::ENCRYPTION_INFO_STRING,
$salt
);
return new DerivedKeys($akey, $ekey);
} elseif ($this->secret_type === self::SECRET_TYPE_PASSWORD) {
Core::ensureTrue(\is_string($this->secret));
/* Our PBKDF2 polyfill is vulnerable to a DoS attack documented in
* GitHub issue #230. The fix is to pre-hash the password to ensure
* it is short. We do the prehashing here instead of in pbkdf2() so
* that pbkdf2() still computes the function as defined by the
* standard. */
/**
* @psalm-suppress PossiblyInvalidArgument
*/
$prehash = \hash(Core::HASH_FUNCTION_NAME, $this->secret, true);
$prekey = Core::pbkdf2(
Core::HASH_FUNCTION_NAME,
$prehash,
$salt,
self::PBKDF2_ITERATIONS,
Core::KEY_BYTE_SIZE,
true
);
$akey = Core::HKDF(
Core::HASH_FUNCTION_NAME,
$prekey,
Core::KEY_BYTE_SIZE,
Core::AUTHENTICATION_INFO_STRING,
$salt
);
/* Note the cryptographic re-use of $salt here. */
$ekey = Core::HKDF(
Core::HASH_FUNCTION_NAME,
$prekey,
Core::KEY_BYTE_SIZE,
Core::ENCRYPTION_INFO_STRING,
$salt
);
return new DerivedKeys($akey, $ekey);
} else {
throw new Ex\EnvironmentIsBrokenException('Bad secret type.');
}
}
/**
* Constructor for KeyOrPassword.
*
* @param int $secret_type
* @param mixed $secret (either a Key or a password string)
*/
private function __construct(
$secret_type,
#[\SensitiveParameter]
$secret
)
{
// The constructor is private, so these should never throw.
if ($secret_type === self::SECRET_TYPE_KEY) {
Core::ensureTrue($secret instanceof Key);
} elseif ($secret_type === self::SECRET_TYPE_PASSWORD) {
Core::ensureTrue(\is_string($secret));
} else {
throw new Ex\EnvironmentIsBrokenException('Bad secret type.');
}
$this->secret_type = $secret_type;
$this->secret = $secret;
}
}
How it Works
Getting started with NFC Pay is simple and quick. Register your account, add your cards, and you're ready to make payments in no time. Whether you're paying at a store, sending money to a friend, or managing your merchant transactions, NFC Pay makes it easy and secure.
Download the NFC Pay app and sign up with your email or phone number. Complete the registration process by verifying your identity, and set up your secure PIN to protect your account.
Link your debit or credit cards to your NFC Pay wallet. Simply scan your card or enter the details manually, and you’re set to load funds, shop, and pay with ease.
To pay, simply tap your phone or scan the QR code at checkout. You can also transfer money to other users with a few taps. Enjoy fast, contactless payments with top-notch security.
Security System
NFC Pay prioritizes your security with advanced features that safeguard every transaction. From SMS or email verification to end-to-end encryption, we've implemented robust measures to ensure your data is always protected. Our security systems are designed to prevent unauthorized access and provide you with a safe and reliable payment experience.
Receive instant alerts for every transaction to keep track of your account activities.
Verify your identity through our Know Your Customer process to prevent fraud and enhance security.
Dramatically supply transparent backward deliverables before caward comp internal or "organic" sources.
All your data and transactions are encrypted, ensuring that your sensitive information remains private.
Monitor unusual activity patterns to detect and prevent suspicious behavior in real-time.
Why Choice Us
With NFC Pay, you get a trusted platform backed by proven expertise and a commitment to quality. We put our customers first, offering innovative solutions tailored to your needs, ensuring every transaction is secure, swift, and seamless.
Our team brings years of experience in the digital payments industry to provide reliable services.
We prioritize excellence, ensuring that every aspect of our platform meets the highest standards.
Your needs drive our solutions, and we are dedicated to delivering a superior user experience.
We continuously evolve, integrating the latest technologies to enhance your payment experience.
Testimonial Section
Hear from our users who trust NFC Pay for their everyday transactions. Our commitment to security, ease of use, and exceptional service shines through in their experiences. See why our clients choose NFC Pay for their payment needs and how it has transformed the way they manage their finances.
App Section
Unlock the full potential of NFC Pay by downloading our app, designed to bring secure, swift, and smart transactions to your fingertips. Whether you're paying at a store, transferring money to friends, or managing your business payments, the NFC Pay app makes it effortless. Available on both iOS and Android, it's your all-in-one solution for convenient and reliable digital payments. Download now and experience the future of payments!