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diff --git a/lib/private/Authentication/WebAuthn/Manager.php b/lib/private/Authentication/WebAuthn/Manager.php
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+++ b/lib/private/Authentication/WebAuthn/Manager.php
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+<?php
+declare(strict_types=1);
+/**
+ * @copyright Copyright (c) 2020, Roeland Jago Douma <roeland@famdouma.nl>
+ *
+ * @author Roeland Jago Douma <roeland@famdouma.nl>
+ *
+ * @license GNU AGPL version 3 or any later version
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+namespace OC\Authentication\WebAuthn;
+
+use Cose\Algorithm\Signature\ECDSA\ES256;
+use Cose\Algorithm\Signature\RSA\RS256;
+use Cose\Algorithms;
+use GuzzleHttp\Psr7\ServerRequest;
+use OC\Authentication\WebAuthn\Db\PublicKeyCredentialEntity;
+use OC\Authentication\WebAuthn\Db\PublicKeyCredentialMapper;
+use OCP\AppFramework\Db\DoesNotExistException;
+use OCP\IConfig;
+use OCP\ILogger;
+use OCP\IUser;
+use Webauthn\AttestationStatement\AttestationObjectLoader;
+use Webauthn\AttestationStatement\AttestationStatementSupportManager;
+use Webauthn\AttestationStatement\NoneAttestationStatementSupport;
+use Webauthn\AuthenticationExtensions\ExtensionOutputCheckerHandler;
+use Webauthn\AuthenticatorAssertionResponse;
+use Webauthn\AuthenticatorAssertionResponseValidator;
+use Webauthn\AuthenticatorAttestationResponse;
+use Webauthn\AuthenticatorAttestationResponseValidator;
+use Webauthn\AuthenticatorSelectionCriteria;
+use Webauthn\PublicKeyCredentialCreationOptions;
+use Webauthn\PublicKeyCredentialDescriptor;
+use Webauthn\PublicKeyCredentialLoader;
+use Webauthn\PublicKeyCredentialParameters;
+use Webauthn\PublicKeyCredentialRequestOptions;
+use Webauthn\PublicKeyCredentialRpEntity;
+use Webauthn\PublicKeyCredentialSource;
+use Webauthn\PublicKeyCredentialUserEntity;
+use Webauthn\TokenBinding\TokenBindingNotSupportedHandler;
+
+class Manager {
+
+	/** @var CredentialRepository */
+	private $repository;
+
+	/** @var PublicKeyCredentialMapper */
+	private $credentialMapper;
+
+	/** @var ILogger */
+	private $logger;
+
+	/** @var IConfig */
+	private $config;
+
+	public function __construct(
+		CredentialRepository $repository,
+		PublicKeyCredentialMapper $credentialMapper,
+		ILogger $logger,
+		IConfig $config
+	) {
+		$this->repository = $repository;
+		$this->credentialMapper = $credentialMapper;
+		$this->logger = $logger;
+		$this->config = $config;
+	}
+
+	public function startRegistration(IUser $user, string $serverHost): PublicKeyCredentialCreationOptions {
+		$rpEntity = new PublicKeyCredentialRpEntity(
+			'Nextcloud', //Name
+			$this->stripPort($serverHost),        //ID
+			null                            //Icon
+		);
+
+		$userEntity = new PublicKeyCredentialUserEntity(
+			$user->getUID(),                              //Name
+			$user->getUID(),                              //ID
+			$user->getDisplayName()                      //Display name
+//            'https://foo.example.co/avatar/123e4567-e89b-12d3-a456-426655440000' //Icon
+		);
+
+		$challenge = random_bytes(32);
+
+		$publicKeyCredentialParametersList = [
+			new PublicKeyCredentialParameters('public-key', Algorithms::COSE_ALGORITHM_ES256),
+			new PublicKeyCredentialParameters('public-key', Algorithms::COSE_ALGORITHM_RS256),
+		];
+
+		$timeout = 60000;
+
+		$excludedPublicKeyDescriptors = [
+		];
+
+		$authenticatorSelectionCriteria = new AuthenticatorSelectionCriteria();
+
+		return new PublicKeyCredentialCreationOptions(
+			$rpEntity,
+			$userEntity,
+			$challenge,
+			$publicKeyCredentialParametersList,
+			$timeout,
+			$excludedPublicKeyDescriptors,
+			$authenticatorSelectionCriteria,
+			PublicKeyCredentialCreationOptions::ATTESTATION_CONVEYANCE_PREFERENCE_NONE,
+			null
+		);
+	}
+
+	public function finishRegister(PublicKeyCredentialCreationOptions $publicKeyCredentialCreationOptions, string $name, string $data): PublicKeyCredentialEntity {
+		$tokenBindingHandler = new TokenBindingNotSupportedHandler();
+
+		$attestationStatementSupportManager = new AttestationStatementSupportManager();
+		$attestationStatementSupportManager->add(new NoneAttestationStatementSupport());
+
+		$attestationObjectLoader = new AttestationObjectLoader($attestationStatementSupportManager);
+		$publicKeyCredentialLoader = new PublicKeyCredentialLoader($attestationObjectLoader);
+
+		// Extension Output Checker Handler
+		$extensionOutputCheckerHandler = new ExtensionOutputCheckerHandler();
+
+		// Authenticator Attestation Response Validator
+		$authenticatorAttestationResponseValidator = new AuthenticatorAttestationResponseValidator(
+			$attestationStatementSupportManager,
+			$this->repository,
+			$tokenBindingHandler,
+			$extensionOutputCheckerHandler
+		);
+
+		try {
+			// Load the data
+			$publicKeyCredential = $publicKeyCredentialLoader->load($data);
+			$response = $publicKeyCredential->getResponse();
+
+			// Check if the response is an Authenticator Attestation Response
+			if (!$response instanceof AuthenticatorAttestationResponse) {
+				throw new \RuntimeException('Not an authenticator attestation response');
+			}
+
+			// Check the response against the request
+			$request = ServerRequest::fromGlobals();
+
+			$publicKeyCredentialSource = $authenticatorAttestationResponseValidator->check(
+				$response,
+				$publicKeyCredentialCreationOptions,
+				$request);
+		} catch (\Throwable $exception) {
+			throw $exception;
+		}
+
+		// Persist the data
+		return $this->repository->saveAndReturnCredentialSource($publicKeyCredentialSource, $name);
+	}
+
+	private function stripPort(string $serverHost): string {
+		return preg_replace('/(:\d+$)/', '', $serverHost);
+	}
+
+	public function startAuthentication(string $uid, string $serverHost): PublicKeyCredentialRequestOptions {
+				// List of registered PublicKeyCredentialDescriptor classes associated to the user
+		$registeredPublicKeyCredentialDescriptors = array_map(function (PublicKeyCredentialEntity $entity) {
+			$credential = $entity->toPublicKeyCredentialSource();
+			return new PublicKeyCredentialDescriptor(
+				$credential->getType(),
+				$credential->getPublicKeyCredentialId()
+			);
+		}, $this->credentialMapper->findAllForUid($uid));
+
+		// Public Key Credential Request Options
+		return new PublicKeyCredentialRequestOptions(
+			random_bytes(32),                                                    // Challenge
+			60000,                                                              // Timeout
+			$this->stripPort($serverHost),                                                                  // Relying Party ID
+			$registeredPublicKeyCredentialDescriptors                                  // Registered PublicKeyCredentialDescriptor classes
+		);
+	}
+
+	public function finishAuthentication(PublicKeyCredentialRequestOptions $publicKeyCredentialRequestOptions, string $data, string $uid) {
+		$attestationStatementSupportManager = new AttestationStatementSupportManager();
+		$attestationStatementSupportManager->add(new NoneAttestationStatementSupport());
+
+		$attestationObjectLoader = new AttestationObjectLoader($attestationStatementSupportManager);
+		$publicKeyCredentialLoader = new PublicKeyCredentialLoader($attestationObjectLoader);
+
+		$tokenBindingHandler = new TokenBindingNotSupportedHandler();
+		$extensionOutputCheckerHandler = new ExtensionOutputCheckerHandler();
+		$algorithmManager = new \Cose\Algorithm\Manager();
+		$algorithmManager->add(new ES256());
+		$algorithmManager->add(new RS256());
+
+		$authenticatorAssertionResponseValidator = new AuthenticatorAssertionResponseValidator(
+			$this->repository,
+			$tokenBindingHandler,
+			$extensionOutputCheckerHandler,
+			$algorithmManager
+		);
+
+		try {
+			$this->logger->debug('Loading publickey credentials from: ' . $data);
+
+			// Load the data
+			$publicKeyCredential = $publicKeyCredentialLoader->load($data);
+			$response = $publicKeyCredential->getResponse();
+
+			// Check if the response is an Authenticator Attestation Response
+			if (!$response instanceof AuthenticatorAssertionResponse) {
+				throw new \RuntimeException('Not an authenticator attestation response');
+			}
+
+			// Check the response against the request
+			$request = ServerRequest::fromGlobals();
+
+			$publicKeyCredentialSource = $authenticatorAssertionResponseValidator->check(
+				$publicKeyCredential->getRawId(),
+				$response,
+				$publicKeyCredentialRequestOptions,
+				$request,
+				$uid
+			);
+
+		} catch (\Throwable $e) {
+			throw $e;
+		}
+
+
+
+		return true;
+	}
+
+	public function deleteRegistration(IUser $user, int $id): void {
+		try {
+			$entry = $this->credentialMapper->findById($user->getUID(), $id);
+		} catch (DoesNotExistException $e) {
+			$this->logger->warning("WebAuthn device $id does not exist, can't delete it");
+			return;
+		}
+
+		$this->credentialMapper->delete($entry);
+	}
+
+	public function isWebAuthnAvailable(): bool {
+		if (!extension_loaded('bcmath')) {
+			return false;
+		}
+
+		if (!extension_loaded('gmp')) {
+			return false;
+		}
+
+		if (!$this->config->getSystemValueBool('auth.webauthn.enabled', true)) {
+			return false;
+		}
+
+		return true;
+	}
+}