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<?php |
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|
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declare(strict_types=1); |
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|
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/* |
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* The MIT License (MIT) |
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* |
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* Copyright (c) 2014-2021 Spomky-Labs |
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* |
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* This software may be modified and distributed under the terms |
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* of the MIT license. See the LICENSE file for details. |
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*/ |
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|
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namespace Webauthn\MetadataService; |
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|
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use Assert\Assertion; |
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use Base64Url\Base64Url; |
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use Jose\Component\KeyManagement\JWKFactory; |
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use Jose\Component\Signature\Algorithm\ES256; |
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use Jose\Component\Signature\Serializer\CompactSerializer; |
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use Psr\Http\Client\ClientInterface; |
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use Psr\Http\Message\RequestFactoryInterface; |
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use function Safe\json_decode; |
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use function Safe\sprintf; |
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|
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/** |
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* @deprecated This class is deprecated since v3.3 and will be removed in v4.0 |
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*/ |
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class MetadataStatementFetcher |
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{ |
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public static function fetchTableOfContent(string $uri, ClientInterface $client, RequestFactoryInterface $requestFactory, array $additionalHeaders = []): MetadataTOCPayload |
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{ |
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$content = self::fetch($uri, $client, $requestFactory, $additionalHeaders); |
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$payload = self::getJwsPayload($content); |
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$data = json_decode($payload, true); |
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|
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return MetadataTOCPayload::createFromArray($data); |
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} |
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|
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public static function fetchMetadataStatement(string $uri, bool $isBase64UrlEncoded, ClientInterface $client, RequestFactoryInterface $requestFactory, array $additionalHeaders = [], string $hash = '', string $hashingFunction = 'sha256'): MetadataStatement |
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{ |
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$payload = self::fetch($uri, $client, $requestFactory, $additionalHeaders); |
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if ('' !== $hash) { |
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Assertion::true(hash_equals($hash, hash($hashingFunction, $payload, true)), 'The hash cannot be verified. The metadata statement shall be rejected'); |
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} |
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$json = $isBase64UrlEncoded ? Base64Url::decode($payload) : $payload; |
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$data = json_decode($json, true); |
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|
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return MetadataStatement::createFromArray($data); |
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} |
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|
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private static function fetch(string $uri, ClientInterface $client, RequestFactoryInterface $requestFactory, array $additionalHeaders = []): string |
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{ |
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$request = $requestFactory->createRequest('GET', $uri); |
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foreach ($additionalHeaders as $k => $v) { |
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$request = $request->withHeader($k, $v); |
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} |
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$response = $client->sendRequest($request); |
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Assertion::eq(200, $response->getStatusCode(), sprintf('Unable to contact the server. Response code is %d', $response->getStatusCode())); |
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$content = $response->getBody()->getContents(); |
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Assertion::notEmpty($content, 'Unable to contact the server. The response has no content'); |
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|
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return $content; |
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} |
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|
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private static function getJwsPayload(string $token): string |
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{ |
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$jws = (new CompactSerializer())->unserialize($token); |
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Assertion::eq(1, $jws->countSignatures(), 'Invalid response from the metadata service. Only one signature shall be present.'); |
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$signature = $jws->getSignature(0); |
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$payload = $jws->getPayload(); |
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Assertion::notEmpty($payload, 'Invalid response from the metadata service. The token payload is empty.'); |
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$header = $signature->getProtectedHeader(); |
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Assertion::keyExists($header, 'alg', 'The "alg" parameter is missing.'); |
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Assertion::eq($header['alg'], 'ES256', 'The expected "alg" parameter value should be "ES256".'); |
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Assertion::keyExists($header, 'x5c', 'The "x5c" parameter is missing.'); |
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Assertion::isArray($header['x5c'], 'The "x5c" parameter should be an array.'); |
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$key = JWKFactory::createFromX5C($header['x5c']); |
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$algorithm = new ES256(); |
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$isValid = $algorithm->verify($key, $signature->getEncodedProtectedHeader().'.'.$jws->getEncodedPayload(), $signature->getSignature()); |
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Assertion::true($isValid, 'Invalid response from the metadata service. The token signature is invalid.'); |
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|
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return $jws->getPayload(); |
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} |
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} |
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