<?php
declare(strict_types=1);

namespace Lcobucci\JWT\Signer;

use Lcobucci\JWT\Signer;
use OpenSSLAsymmetricKey;

use function array_key_exists;
use function assert;
use function is_array;
use function is_bool;
use function is_string;
use function openssl_error_string;
use function openssl_free_key;
use function openssl_pkey_get_details;
use function openssl_pkey_get_private;
use function openssl_pkey_get_public;
use function openssl_sign;
use function openssl_verify;

abstract class OpenSSL implements Signer
{
    /**
     * @throws CannotSignPayload
     * @throws InvalidKeyProvided
     */
    final protected function createSignature(
        string $pem,
        string $passphrase,
        string $payload
    ): string {
        $key = $this->getPrivateKey($pem, $passphrase);

        try {
            $signature = '';

            if (! openssl_sign($payload, $signature, $key, $this->algorithm())) {
                $error = openssl_error_string();
                assert(is_string($error));

                throw CannotSignPayload::errorHappened($error);
            }

            return $signature;
        } finally {
            $this->freeKey($key);
        }
    }

    /**
     * @return resource|OpenSSLAsymmetricKey
     *
     * @throws CannotSignPayload
     */
    private function getPrivateKey(string $pem, string $passphrase)
    {
        $privateKey = openssl_pkey_get_private($pem, $passphrase);
        $this->validateKey($privateKey);

        return $privateKey;
    }

    /** @throws InvalidKeyProvided */
    final protected function verifySignature(
        string $expected,
        string $payload,
        string $pem
    ): bool {
        $key    = $this->getPublicKey($pem);
        $result = openssl_verify($payload, $expected, $key, $this->algorithm());
        $this->freeKey($key);

        return $result === 1;
    }

    /**
     * @return resource|OpenSSLAsymmetricKey
     *
     * @throws InvalidKeyProvided
     */
    private function getPublicKey(string $pem)
    {
        $publicKey = openssl_pkey_get_public($pem);
        $this->validateKey($publicKey);

        return $publicKey;
    }

    /**
     * Raises an exception when the key type is not the expected type
     *
     * @param resource|OpenSSLAsymmetricKey|bool $key
     *
     * @throws InvalidKeyProvided
     */
    private function validateKey($key): void
    {
        if (is_bool($key)) {
            $error = openssl_error_string();
            assert(is_string($error));

            throw InvalidKeyProvided::cannotBeParsed($error);
        }

        $details = openssl_pkey_get_details($key);
        assert(is_array($details));

        if (! array_key_exists('key', $details) || $details['type'] !== $this->keyType()) {
            throw InvalidKeyProvided::incompatibleKey();
        }
    }

    /** @param resource|OpenSSLAsymmetricKey $key */
    private function freeKey($key): void
    {
        if ($key instanceof OpenSSLAsymmetricKey) {
            return;
        }

        openssl_free_key($key); // Deprecated and no longer necessary as of PHP >= 8.0
    }

    /**
     * Returns the type of key to be used to create/verify the signature (using OpenSSL constants)
     *
     * @internal
     */
    abstract public function keyType(): int;

    /**
     * Returns which algorithm to be used to create/verify the signature (using OpenSSL constants)
     *
     * @internal
     */
    abstract public function algorithm(): int;
}

• [D] Ecdsa
• [D] Hmac
• [D] Key
• [D] Rsa
• [F] CannotSignPayload.php
  Delete
• [F] Ecdsa.php
  Delete
• [F] Hmac.php
  Delete
• [F] InvalidKeyProvided.php
  Delete
• [F] Key.php
  Delete
• [F] None.php
  Delete
• [F] OpenSSL.php
  Delete
• [F] Rsa.php
  Delete

About Section

About NFC Pay: Our Story and Mission

NFC Pay was founded with a vision to transform the way people handle transactions. Our journey is defined by a commitment to innovation, security, and convenience. We strive to deliver seamless, user-friendly payment solutions that make everyday transactions effortless and secure. Our mission is to empower you to pay with ease and confidence, anytime, anywhere.

• Simplifying Payments, One Tap at a Time.
• Reinventing Your Wallet for Modern Convenience.
• Smart Payments for a Effortless Lifestyle.
• Experience the Ease of Tap and Pay.
• Innovative Solutions for Your Daily Transactions.

FAQ Section

Frequently Asked Questions About NFC Pay

Here are answers to some common questions about NFC Pay. We aim to provide clear and concise information to help you understand how our platform works and how it can benefit you. If you have any further inquiries, please don’t hesitate to contact our support team.

How do I register for NFC Pay?

Download the app and sign up using your email or phone number, then complete the verification process.

Is my payment information secure?

Yes, we use advanced encryption and security protocols to protect your payment details.

Can I add multiple cards to my NFC Pay wallet?

Absolutely, you can link multiple debit or credit cards to your wallet.

How do I transfer money to another user?

Go to the transfer section, select the recipient, enter the amount, and authorize the transfer.

What should I do if I forget my PIN?

Use the “Forgot PIN” feature in the app to reset it following the provided instructions.

How can I activate my merchant account?

Sign up for a merchant account through the app and follow the setup instructions to start accepting payments.

Can I track my payment status?

Yes, you can view and track your payment status in the account dashboard