/home/kueuepay/public_html/vendor/league/oauth2-server/src/Grant/AuthCodeGrant.php
<?php
/**
 * @author      Alex Bilbie <hello@alexbilbie.com>
 * @copyright   Copyright (c) Alex Bilbie
 * @license     http://mit-license.org/
 *
 * @link        https://github.com/thephpleague/oauth2-server
 */

namespace League\OAuth2\Server\Grant;

use DateInterval;
use DateTimeImmutable;
use Exception;
use League\OAuth2\Server\CodeChallengeVerifiers\CodeChallengeVerifierInterface;
use League\OAuth2\Server\CodeChallengeVerifiers\PlainVerifier;
use League\OAuth2\Server\CodeChallengeVerifiers\S256Verifier;
use League\OAuth2\Server\Entities\ClientEntityInterface;
use League\OAuth2\Server\Entities\UserEntityInterface;
use League\OAuth2\Server\Exception\OAuthServerException;
use League\OAuth2\Server\Repositories\AuthCodeRepositoryInterface;
use League\OAuth2\Server\Repositories\RefreshTokenRepositoryInterface;
use League\OAuth2\Server\RequestAccessTokenEvent;
use League\OAuth2\Server\RequestEvent;
use League\OAuth2\Server\RequestRefreshTokenEvent;
use League\OAuth2\Server\RequestTypes\AuthorizationRequest;
use League\OAuth2\Server\ResponseTypes\RedirectResponse;
use League\OAuth2\Server\ResponseTypes\ResponseTypeInterface;
use LogicException;
use Psr\Http\Message\ServerRequestInterface;
use stdClass;

class AuthCodeGrant extends AbstractAuthorizeGrant
{
    /**
     * @var DateInterval
     */
    private $authCodeTTL;

    /**
     * @var bool
     */
    private $requireCodeChallengeForPublicClients = true;

    /**
     * @var CodeChallengeVerifierInterface[]
     */
    private $codeChallengeVerifiers = [];

    /**
     * @param AuthCodeRepositoryInterface     $authCodeRepository
     * @param RefreshTokenRepositoryInterface $refreshTokenRepository
     * @param DateInterval                    $authCodeTTL
     *
     * @throws Exception
     */
    public function __construct(
        AuthCodeRepositoryInterface $authCodeRepository,
        RefreshTokenRepositoryInterface $refreshTokenRepository,
        DateInterval $authCodeTTL
    ) {
        $this->setAuthCodeRepository($authCodeRepository);
        $this->setRefreshTokenRepository($refreshTokenRepository);
        $this->authCodeTTL = $authCodeTTL;
        $this->refreshTokenTTL = new DateInterval('P1M');

        if (\in_array('sha256', \hash_algos(), true)) {
            $s256Verifier = new S256Verifier();
            $this->codeChallengeVerifiers[$s256Verifier->getMethod()] = $s256Verifier;
        }

        $plainVerifier = new PlainVerifier();
        $this->codeChallengeVerifiers[$plainVerifier->getMethod()] = $plainVerifier;
    }

    /**
     * Disable the requirement for a code challenge for public clients.
     */
    public function disableRequireCodeChallengeForPublicClients()
    {
        $this->requireCodeChallengeForPublicClients = false;
    }

    /**
     * Respond to an access token request.
     *
     * @param ServerRequestInterface $request
     * @param ResponseTypeInterface  $responseType
     * @param DateInterval           $accessTokenTTL
     *
     * @throws OAuthServerException
     *
     * @return ResponseTypeInterface
     */
    public function respondToAccessTokenRequest(
        ServerRequestInterface $request,
        ResponseTypeInterface $responseType,
        DateInterval $accessTokenTTL
    ) {
        list($clientId) = $this->getClientCredentials($request);

        $client = $this->getClientEntityOrFail($clientId, $request);

        // Only validate the client if it is confidential
        if ($client->isConfidential()) {
            $this->validateClient($request);
        }

        $encryptedAuthCode = $this->getRequestParameter('code', $request, null);

        if (!\is_string($encryptedAuthCode)) {
            throw OAuthServerException::invalidRequest('code');
        }

        try {
            $authCodePayload = \json_decode($this->decrypt($encryptedAuthCode));

            $this->validateAuthorizationCode($authCodePayload, $client, $request);

            $scopes = $this->scopeRepository->finalizeScopes(
                $this->validateScopes($authCodePayload->scopes),
                $this->getIdentifier(),
                $client,
                $authCodePayload->user_id
            );
        } catch (LogicException $e) {
            throw OAuthServerException::invalidRequest('code', 'Cannot decrypt the authorization code', $e);
        }

        $codeVerifier = $this->getRequestParameter('code_verifier', $request, null);

        // If a code challenge isn't present but a code verifier is, reject the request to block PKCE downgrade attack
        if (empty($authCodePayload->code_challenge) && $codeVerifier !== null) {
            throw OAuthServerException::invalidRequest(
                'code_challenge',
                'code_verifier received when no code_challenge is present'
            );
        }

        if (!empty($authCodePayload->code_challenge)) {
            $this->validateCodeChallenge($authCodePayload, $codeVerifier);
        }

        // Issue and persist new access token
        $accessToken = $this->issueAccessToken($accessTokenTTL, $client, $authCodePayload->user_id, $scopes);
        $this->getEmitter()->emit(new RequestAccessTokenEvent(RequestEvent::ACCESS_TOKEN_ISSUED, $request, $accessToken));
        $responseType->setAccessToken($accessToken);

        // Issue and persist new refresh token if given
        $refreshToken = $this->issueRefreshToken($accessToken);

        if ($refreshToken !== null) {
            $this->getEmitter()->emit(new RequestRefreshTokenEvent(RequestEvent::REFRESH_TOKEN_ISSUED, $request, $refreshToken));
            $responseType->setRefreshToken($refreshToken);
        }

        // Revoke used auth code
        $this->authCodeRepository->revokeAuthCode($authCodePayload->auth_code_id);

        return $responseType;
    }

    private function validateCodeChallenge($authCodePayload, $codeVerifier)
    {
        if ($codeVerifier === null) {
            throw OAuthServerException::invalidRequest('code_verifier');
        }

        // Validate code_verifier according to RFC-7636
        // @see: https://tools.ietf.org/html/rfc7636#section-4.1
        if (\preg_match('/^[A-Za-z0-9-._~]{43,128}$/', $codeVerifier) !== 1) {
            throw OAuthServerException::invalidRequest(
                'code_verifier',
                'Code Verifier must follow the specifications of RFC-7636.'
            );
        }

        if (\property_exists($authCodePayload, 'code_challenge_method')) {
            if (isset($this->codeChallengeVerifiers[$authCodePayload->code_challenge_method])) {
                $codeChallengeVerifier = $this->codeChallengeVerifiers[$authCodePayload->code_challenge_method];

                if ($codeChallengeVerifier->verifyCodeChallenge($codeVerifier, $authCodePayload->code_challenge) === false) {
                    throw OAuthServerException::invalidGrant('Failed to verify `code_verifier`.');
                }
            } else {
                throw OAuthServerException::serverError(
                    \sprintf(
                        'Unsupported code challenge method `%s`',
                        $authCodePayload->code_challenge_method
                    )
                );
            }
        }
    }

    /**
     * Validate the authorization code.
     *
     * @param stdClass               $authCodePayload
     * @param ClientEntityInterface  $client
     * @param ServerRequestInterface $request
     */
    private function validateAuthorizationCode(
        $authCodePayload,
        ClientEntityInterface $client,
        ServerRequestInterface $request
    ) {
        if (!\property_exists($authCodePayload, 'auth_code_id')) {
            throw OAuthServerException::invalidRequest('code', 'Authorization code malformed');
        }

        if (\time() > $authCodePayload->expire_time) {
            throw OAuthServerException::invalidRequest('code', 'Authorization code has expired');
        }

        if ($this->authCodeRepository->isAuthCodeRevoked($authCodePayload->auth_code_id) === true) {
            throw OAuthServerException::invalidRequest('code', 'Authorization code has been revoked');
        }

        if ($authCodePayload->client_id !== $client->getIdentifier()) {
            throw OAuthServerException::invalidRequest('code', 'Authorization code was not issued to this client');
        }

        // The redirect URI is required in this request
        $redirectUri = $this->getRequestParameter('redirect_uri', $request, null);
        if (empty($authCodePayload->redirect_uri) === false && $redirectUri === null) {
            throw OAuthServerException::invalidRequest('redirect_uri');
        }

        if ($authCodePayload->redirect_uri !== $redirectUri) {
            throw OAuthServerException::invalidRequest('redirect_uri', 'Invalid redirect URI');
        }
    }

    /**
     * Return the grant identifier that can be used in matching up requests.
     *
     * @return string
     */
    public function getIdentifier()
    {
        return 'authorization_code';
    }

    /**
     * {@inheritdoc}
     */
    public function canRespondToAuthorizationRequest(ServerRequestInterface $request)
    {
        return (
            \array_key_exists('response_type', $request->getQueryParams())
            && $request->getQueryParams()['response_type'] === 'code'
            && isset($request->getQueryParams()['client_id'])
        );
    }

    /**
     * {@inheritdoc}
     */
    public function validateAuthorizationRequest(ServerRequestInterface $request)
    {
        $clientId = $this->getQueryStringParameter(
            'client_id',
            $request,
            $this->getServerParameter('PHP_AUTH_USER', $request)
        );

        if ($clientId === null) {
            throw OAuthServerException::invalidRequest('client_id');
        }

        $client = $this->getClientEntityOrFail($clientId, $request);

        $redirectUri = $this->getQueryStringParameter('redirect_uri', $request);

        if ($redirectUri !== null) {
            if (!\is_string($redirectUri)) {
                throw OAuthServerException::invalidRequest('redirect_uri');
            }

            $this->validateRedirectUri($redirectUri, $client, $request);
        } elseif (empty($client->getRedirectUri()) ||
            (\is_array($client->getRedirectUri()) && \count($client->getRedirectUri()) !== 1)) {
            $this->getEmitter()->emit(new RequestEvent(RequestEvent::CLIENT_AUTHENTICATION_FAILED, $request));

            throw OAuthServerException::invalidClient($request);
        }

        $defaultClientRedirectUri = \is_array($client->getRedirectUri())
            ? $client->getRedirectUri()[0]
            : $client->getRedirectUri();

        $scopes = $this->validateScopes(
            $this->getQueryStringParameter('scope', $request, $this->defaultScope),
            $redirectUri ?? $defaultClientRedirectUri
        );

        $stateParameter = $this->getQueryStringParameter('state', $request);

        $authorizationRequest = new AuthorizationRequest();
        $authorizationRequest->setGrantTypeId($this->getIdentifier());
        $authorizationRequest->setClient($client);
        $authorizationRequest->setRedirectUri($redirectUri);

        if ($stateParameter !== null) {
            $authorizationRequest->setState($stateParameter);
        }

        $authorizationRequest->setScopes($scopes);

        $codeChallenge = $this->getQueryStringParameter('code_challenge', $request);

        if ($codeChallenge !== null) {
            $codeChallengeMethod = $this->getQueryStringParameter('code_challenge_method', $request, 'plain');

            if (\array_key_exists($codeChallengeMethod, $this->codeChallengeVerifiers) === false) {
                throw OAuthServerException::invalidRequest(
                    'code_challenge_method',
                    'Code challenge method must be one of ' . \implode(', ', \array_map(
                        function ($method) {
                            return '`' . $method . '`';
                        },
                        \array_keys($this->codeChallengeVerifiers)
                    ))
                );
            }

            // Validate code_challenge according to RFC-7636
            // @see: https://tools.ietf.org/html/rfc7636#section-4.2
            if (\preg_match('/^[A-Za-z0-9-._~]{43,128}$/', $codeChallenge) !== 1) {
                throw OAuthServerException::invalidRequest(
                    'code_challenge',
                    'Code challenge must follow the specifications of RFC-7636.'
                );
            }

            $authorizationRequest->setCodeChallenge($codeChallenge);
            $authorizationRequest->setCodeChallengeMethod($codeChallengeMethod);
        } elseif ($this->requireCodeChallengeForPublicClients && !$client->isConfidential()) {
            throw OAuthServerException::invalidRequest('code_challenge', 'Code challenge must be provided for public clients');
        }

        return $authorizationRequest;
    }

    /**
     * {@inheritdoc}
     */
    public function completeAuthorizationRequest(AuthorizationRequest $authorizationRequest)
    {
        if ($authorizationRequest->getUser() instanceof UserEntityInterface === false) {
            throw new LogicException('An instance of UserEntityInterface should be set on the AuthorizationRequest');
        }

        $finalRedirectUri = $authorizationRequest->getRedirectUri()
                          ?? $this->getClientRedirectUri($authorizationRequest);

        // The user approved the client, redirect them back with an auth code
        if ($authorizationRequest->isAuthorizationApproved() === true) {
            $authCode = $this->issueAuthCode(
                $this->authCodeTTL,
                $authorizationRequest->getClient(),
                $authorizationRequest->getUser()->getIdentifier(),
                $authorizationRequest->getRedirectUri(),
                $authorizationRequest->getScopes()
            );

            $payload = [
                'client_id'             => $authCode->getClient()->getIdentifier(),
                'redirect_uri'          => $authCode->getRedirectUri(),
                'auth_code_id'          => $authCode->getIdentifier(),
                'scopes'                => $authCode->getScopes(),
                'user_id'               => $authCode->getUserIdentifier(),
                'expire_time'           => (new DateTimeImmutable())->add($this->authCodeTTL)->getTimestamp(),
                'code_challenge'        => $authorizationRequest->getCodeChallenge(),
                'code_challenge_method' => $authorizationRequest->getCodeChallengeMethod(),
            ];

            $jsonPayload = \json_encode($payload);

            if ($jsonPayload === false) {
                throw new LogicException('An error was encountered when JSON encoding the authorization request response');
            }

            $response = new RedirectResponse();
            $response->setRedirectUri(
                $this->makeRedirectUri(
                    $finalRedirectUri,
                    [
                        'code'  => $this->encrypt($jsonPayload),
                        'state' => $authorizationRequest->getState(),
                    ]
                )
            );

            return $response;
        }

        // The user denied the client, redirect them back with an error
        throw OAuthServerException::accessDenied(
            'The user denied the request',
            $this->makeRedirectUri(
                $finalRedirectUri,
                [
                    'state' => $authorizationRequest->getState(),
                ]
            )
        );
    }

    /**
     * Get the client redirect URI if not set in the request.
     *
     * @param AuthorizationRequest $authorizationRequest
     *
     * @return string
     */
    private function getClientRedirectUri(AuthorizationRequest $authorizationRequest)
    {
        return \is_array($authorizationRequest->getClient()->getRedirectUri())
                ? $authorizationRequest->getClient()->getRedirectUri()[0]
                : $authorizationRequest->getClient()->getRedirectUri();
    }
}
About
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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.

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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.

faq-img

How do I register for NFC Pay?

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Is my payment information secure?

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Can I add multiple cards to my NFC Pay wallet?

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How can I activate my merchant account?

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Can I track my payment status?

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