diff --git a/lib/composer/composer/autoload_classmap.php b/lib/composer/composer/autoload_classmap.php
index 43e2b75aa6d27bab75ff98eefd8fd7bca8cb97fe..777298866012f16d3aba4d930919c622f596b8bd 100644
--- a/lib/composer/composer/autoload_classmap.php
+++ b/lib/composer/composer/autoload_classmap.php
@@ -422,6 +422,9 @@ return array(
     'OC\\Authentication\\Token\\IProvider' => $baseDir . '/lib/private/Authentication/Token/IProvider.php',
     'OC\\Authentication\\Token\\IToken' => $baseDir . '/lib/private/Authentication/Token/IToken.php',
     'OC\\Authentication\\Token\\Manager' => $baseDir . '/lib/private/Authentication/Token/Manager.php',
+    'OC\\Authentication\\Token\\PublicKeyToken' => $baseDir . '/lib/private/Authentication/Token/PublicKeyToken.php',
+    'OC\\Authentication\\Token\\PublicKeyTokenMapper' => $baseDir . '/lib/private/Authentication/Token/PublicKeyTokenMapper.php',
+    'OC\\Authentication\\Token\\PublicKeyTokenProvider' => $baseDir . '/lib/private/Authentication/Token/PublicKeyTokenProvider.php',
     'OC\\Authentication\\TwoFactorAuth\\Manager' => $baseDir . '/lib/private/Authentication/TwoFactorAuth/Manager.php',
     'OC\\Avatar' => $baseDir . '/lib/private/Avatar.php',
     'OC\\AvatarManager' => $baseDir . '/lib/private/AvatarManager.php',
diff --git a/lib/composer/composer/autoload_static.php b/lib/composer/composer/autoload_static.php
index 34d9f3a73e14e8bc3e07a9f3a28546a235ee786e..be9c71d824649cc7b134ee13c9f0c955178b0252 100644
--- a/lib/composer/composer/autoload_static.php
+++ b/lib/composer/composer/autoload_static.php
@@ -452,6 +452,9 @@ class ComposerStaticInit53792487c5a8370acc0b06b1a864ff4c
         'OC\\Authentication\\Token\\IProvider' => __DIR__ . '/../../..' . '/lib/private/Authentication/Token/IProvider.php',
         'OC\\Authentication\\Token\\IToken' => __DIR__ . '/../../..' . '/lib/private/Authentication/Token/IToken.php',
         'OC\\Authentication\\Token\\Manager' => __DIR__ . '/../../..' . '/lib/private/Authentication/Token/Manager.php',
+        'OC\\Authentication\\Token\\PublicKeyToken' => __DIR__ . '/../../..' . '/lib/private/Authentication/Token/PublicKeyToken.php',
+        'OC\\Authentication\\Token\\PublicKeyTokenMapper' => __DIR__ . '/../../..' . '/lib/private/Authentication/Token/PublicKeyTokenMapper.php',
+        'OC\\Authentication\\Token\\PublicKeyTokenProvider' => __DIR__ . '/../../..' . '/lib/private/Authentication/Token/PublicKeyTokenProvider.php',
         'OC\\Authentication\\TwoFactorAuth\\Manager' => __DIR__ . '/../../..' . '/lib/private/Authentication/TwoFactorAuth/Manager.php',
         'OC\\Avatar' => __DIR__ . '/../../..' . '/lib/private/Avatar.php',
         'OC\\AvatarManager' => __DIR__ . '/../../..' . '/lib/private/AvatarManager.php',
diff --git a/lib/private/Authentication/Token/DefaultToken.php b/lib/private/Authentication/Token/DefaultToken.php
index 67aa89ea66bc36e2c211b0d9b6b94a8c2b207ae9..29c4b5a74ad9e7ebffd5c8ba69a99c2da1eb4b36 100644
--- a/lib/private/Authentication/Token/DefaultToken.php
+++ b/lib/private/Authentication/Token/DefaultToken.php
@@ -37,6 +37,7 @@ use OCP\AppFramework\Db\Entity;
  * @method void setRemember(int $remember)
  * @method void setLastActivity(int $lastactivity)
  * @method int getLastActivity()
+ * @method void setVersion(int $version)
  */
 class DefaultToken extends Entity implements IToken {
 
@@ -73,6 +74,9 @@ class DefaultToken extends Entity implements IToken {
 	/** @var int */
 	protected $expires;
 
+	/** @var int */
+	protected $version;
+
 	public function __construct() {
 		$this->addType('uid', 'string');
 		$this->addType('loginName', 'string');
@@ -85,6 +89,9 @@ class DefaultToken extends Entity implements IToken {
 		$this->addType('lastCheck', 'int');
 		$this->addType('scope', 'string');
 		$this->addType('expires', 'int');
+		$this->addType('version', 'int');
+
+		$this->setVersion(1);
 	}
 
 	public function getId(): int {
diff --git a/lib/private/Authentication/Token/DefaultTokenMapper.php b/lib/private/Authentication/Token/DefaultTokenMapper.php
index a67d7d151e9bba1332ae753fec5b5ce63e2ed660..0a3f32ffb460c3a5fb945e32fc7b4defe7d8380b 100644
--- a/lib/private/Authentication/Token/DefaultTokenMapper.php
+++ b/lib/private/Authentication/Token/DefaultTokenMapper.php
@@ -50,8 +50,8 @@ class DefaultTokenMapper extends QBMapper {
 		/* @var $qb IQueryBuilder */
 		$qb = $this->db->getQueryBuilder();
 		$qb->delete('authtoken')
-			->where($qb->expr()->eq('token', $qb->createParameter('token')))
-			->setParameter('token', $token)
+			->where($qb->expr()->eq('token', $qb->createNamedParameter($token, IQueryBuilder::PARAM_STR)))
+			->andWhere($qb->expr()->eq('version', $qb->createNamedParameter(1, IQueryBuilder::PARAM_INT)))
 			->execute();
 	}
 
@@ -66,6 +66,7 @@ class DefaultTokenMapper extends QBMapper {
 			->where($qb->expr()->lt('last_activity', $qb->createNamedParameter($olderThan, IQueryBuilder::PARAM_INT)))
 			->andWhere($qb->expr()->eq('type', $qb->createNamedParameter(IToken::TEMPORARY_TOKEN, IQueryBuilder::PARAM_INT)))
 			->andWhere($qb->expr()->eq('remember', $qb->createNamedParameter($remember, IQueryBuilder::PARAM_INT)))
+			->andWhere($qb->expr()->eq('version', $qb->createNamedParameter(1, IQueryBuilder::PARAM_INT)))
 			->execute();
 	}
 
@@ -79,9 +80,10 @@ class DefaultTokenMapper extends QBMapper {
 	public function getToken(string $token): DefaultToken {
 		/* @var $qb IQueryBuilder */
 		$qb = $this->db->getQueryBuilder();
-		$result = $qb->select('*')
+		$result = $qb->select('id', 'uid', 'login_name', 'password', 'name', 'token', 'type', 'remember', 'last_activity', 'last_check', 'scope', 'expires', 'version')
 			->from('authtoken')
 			->where($qb->expr()->eq('token', $qb->createNamedParameter($token)))
+			->andWhere($qb->expr()->eq('version', $qb->createNamedParameter(1, IQueryBuilder::PARAM_INT)))
 			->execute();
 
 		$data = $result->fetch();
@@ -102,9 +104,10 @@ class DefaultTokenMapper extends QBMapper {
 	public function getTokenById(int $id): DefaultToken {
 		/* @var $qb IQueryBuilder */
 		$qb = $this->db->getQueryBuilder();
-		$result = $qb->select('*')
+		$result = $qb->select('id', 'uid', 'login_name', 'password', 'name', 'token', 'type', 'remember', 'last_activity', 'last_check', 'scope', 'expires', 'version')
 			->from('authtoken')
 			->where($qb->expr()->eq('id', $qb->createNamedParameter($id)))
+			->andWhere($qb->expr()->eq('version', $qb->createNamedParameter(1, IQueryBuilder::PARAM_INT)))
 			->execute();
 
 		$data = $result->fetch();
@@ -127,9 +130,10 @@ class DefaultTokenMapper extends QBMapper {
 	public function getTokenByUser(IUser $user): array {
 		/* @var $qb IQueryBuilder */
 		$qb = $this->db->getQueryBuilder();
-		$qb->select('*')
+		$qb->select('id', 'uid', 'login_name', 'password', 'name', 'token', 'type', 'remember', 'last_activity', 'last_check', 'scope', 'expires', 'version')
 			->from('authtoken')
 			->where($qb->expr()->eq('uid', $qb->createNamedParameter($user->getUID())))
+			->andWhere($qb->expr()->eq('version', $qb->createNamedParameter(1, IQueryBuilder::PARAM_INT)))
 			->setMaxResults(1000);
 		$result = $qb->execute();
 		$data = $result->fetchAll();
@@ -151,7 +155,8 @@ class DefaultTokenMapper extends QBMapper {
 		$qb = $this->db->getQueryBuilder();
 		$qb->delete('authtoken')
 			->where($qb->expr()->eq('id', $qb->createNamedParameter($id)))
-			->andWhere($qb->expr()->eq('uid', $qb->createNamedParameter($user->getUID())));
+			->andWhere($qb->expr()->eq('uid', $qb->createNamedParameter($user->getUID())))
+			->andWhere($qb->expr()->eq('version', $qb->createNamedParameter(1, IQueryBuilder::PARAM_INT)));
 		$qb->execute();
 	}
 
@@ -163,7 +168,8 @@ class DefaultTokenMapper extends QBMapper {
 	public function deleteByName(string $name) {
 		$qb = $this->db->getQueryBuilder();
 		$qb->delete('authtoken')
-			->where($qb->expr()->eq('name', $qb->createNamedParameter($name), IQueryBuilder::PARAM_STR));
+			->where($qb->expr()->eq('name', $qb->createNamedParameter($name), IQueryBuilder::PARAM_STR))
+			->andWhere($qb->expr()->eq('version', $qb->createNamedParameter(1, IQueryBuilder::PARAM_INT)));
 		$qb->execute();
 	}
 
diff --git a/lib/private/Authentication/Token/Manager.php b/lib/private/Authentication/Token/Manager.php
index 4465c288c8cd6c0381151691d98243cfce245606..85fe91cdf14be6224037ced75d3b118264c46840 100644
--- a/lib/private/Authentication/Token/Manager.php
+++ b/lib/private/Authentication/Token/Manager.php
@@ -76,9 +76,9 @@ class Manager implements IProvider {
 	public function updateToken(IToken $token) {
 		if ($token instanceof DefaultToken) {
 			$this->defaultTokenProvider->updateToken($token);
+		} else {
+			throw new InvalidTokenException();
 		}
-
-		throw new InvalidTokenException();
 	}
 
 	/**
@@ -90,9 +90,9 @@ class Manager implements IProvider {
 	public function updateTokenActivity(IToken $token) {
 		if ($token instanceof DefaultToken) {
 			$this->defaultTokenProvider->updateTokenActivity($token);
+		} else {
+			throw new InvalidTokenException();
 		}
-
-		throw new InvalidTokenException();
 	}
 
 	/**
diff --git a/lib/private/Authentication/Token/PublicKeyToken.php b/lib/private/Authentication/Token/PublicKeyToken.php
new file mode 100644
index 0000000000000000000000000000000000000000..18b27075772360a14e1548d96adbf7a10ec1156f
--- /dev/null
+++ b/lib/private/Authentication/Token/PublicKeyToken.php
@@ -0,0 +1,216 @@
+<?php
+declare(strict_types=1);
+/**
+ * @copyright Copyright (c) 2018 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\Token;
+
+use OCP\AppFramework\Db\Entity;
+
+/**
+ * @method void setId(int $id)
+ * @method void setUid(string $uid);
+ * @method void setLoginName(string $loginname)
+ * @method void setName(string $name)
+ * @method string getToken()
+ * @method void setType(int $type)
+ * @method int getType()
+ * @method void setRemember(int $remember)
+ * @method void setLastActivity(int $lastactivity)
+ * @method int getLastActivity()
+ * @method string getPrivateKey()
+ * @method void setPrivateKey(string $key)
+ * @method string getPublicKey()
+ * @method void setPublicKey(string $key)
+ * @method void setVersion(int $version)
+ */
+class PublicKeyToken extends Entity implements IToken {
+
+	/** @var string user UID */
+	protected $uid;
+
+	/** @var string login name used for generating the token */
+	protected $loginName;
+
+	/** @var string encrypted user password */
+	protected $password;
+
+	/** @var string token name (e.g. browser/OS) */
+	protected $name;
+
+	/** @var string */
+	protected $token;
+
+	/** @var int */
+	protected $type;
+
+	/** @var int */
+	protected $remember;
+
+	/** @var int */
+	protected $lastActivity;
+
+	/** @var int */
+	protected $lastCheck;
+
+	/** @var string */
+	protected $scope;
+
+	/** @var int */
+	protected $expires;
+
+	/** @var string */
+	protected $privateKey;
+
+	/** @var string */
+	protected $publicKey;
+
+	/** @var int */
+	protected $version;
+
+	public function __construct() {
+		$this->addType('uid', 'string');
+		$this->addType('loginName', 'string');
+		$this->addType('password', 'string');
+		$this->addType('name', 'string');
+		$this->addType('token', 'string');
+		$this->addType('type', 'int');
+		$this->addType('remember', 'int');
+		$this->addType('lastActivity', 'int');
+		$this->addType('lastCheck', 'int');
+		$this->addType('scope', 'string');
+		$this->addType('expires', 'int');
+		$this->addType('publicKey', 'string');
+		$this->addType('privateKey', 'string');
+		$this->addType('version', 'int');
+
+		$this->setVersion(2);
+	}
+
+	public function getId(): int {
+		return $this->id;
+	}
+
+	public function getUID(): string {
+		return $this->uid;
+	}
+
+	/**
+	 * Get the login name used when generating the token
+	 *
+	 * @return string
+	 */
+	public function getLoginName(): string {
+		return parent::getLoginName();
+	}
+
+	/**
+	 * Get the (encrypted) login password
+	 *
+	 * @return string|null
+	 */
+	public function getPassword() {
+		return parent::getPassword();
+	}
+
+	public function jsonSerialize() {
+		return [
+			'id' => $this->id,
+			'name' => $this->name,
+			'lastActivity' => $this->lastActivity,
+			'type' => $this->type,
+			'scope' => $this->getScopeAsArray()
+		];
+	}
+
+	/**
+	 * Get the timestamp of the last password check
+	 *
+	 * @return int
+	 */
+	public function getLastCheck(): int {
+		return parent::getLastCheck();
+	}
+
+	/**
+	 * Get the timestamp of the last password check
+	 *
+	 * @param int $time
+	 */
+	public function setLastCheck(int $time) {
+		parent::setLastCheck($time);
+	}
+
+	public function getScope(): string {
+		$scope = parent::getScope();
+		if ($scope === null) {
+			return '';
+		}
+
+		return $scope;
+	}
+
+	public function getScopeAsArray(): array {
+		$scope = json_decode($this->getScope(), true);
+		if (!$scope) {
+			return [
+				'filesystem'=> true
+			];
+		}
+		return $scope;
+	}
+
+	public function setScope($scope) {
+		if (\is_array($scope)) {
+			parent::setScope(json_encode($scope));
+		} else {
+			parent::setScope((string)$scope);
+		}
+	}
+
+	public function getName(): string {
+		return parent::getName();
+	}
+
+	public function getRemember(): int {
+		return parent::getRemember();
+	}
+
+	public function setToken(string $token) {
+		parent::setToken($token);
+	}
+
+	public function setPassword(string $password = null) {
+		parent::setPassword($password);
+	}
+
+	public function setExpires($expires) {
+		parent::setExpires($expires);
+	}
+
+	/**
+	 * @return int|null
+	 */
+	public function getExpires() {
+		return parent::getExpires();
+	}
+}
diff --git a/lib/private/Authentication/Token/PublicKeyTokenMapper.php b/lib/private/Authentication/Token/PublicKeyTokenMapper.php
new file mode 100644
index 0000000000000000000000000000000000000000..0d5657cb5824f935884098289235a8564938c159
--- /dev/null
+++ b/lib/private/Authentication/Token/PublicKeyTokenMapper.php
@@ -0,0 +1,167 @@
+<?php
+declare(strict_types=1);
+/**
+ * @copyright Copyright (c) 2018 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\Token;
+
+use OCP\AppFramework\Db\DoesNotExistException;
+use OCP\AppFramework\Db\QBMapper;
+use OCP\DB\QueryBuilder\IQueryBuilder;
+use OCP\IDBConnection;
+use OCP\IUser;
+
+class PublicKeyTokenMapper extends QBMapper {
+
+	public function __construct(IDBConnection $db) {
+		parent::__construct($db, 'authtoken');
+	}
+
+	/**
+	 * Invalidate (delete) a given token
+	 *
+	 * @param string $token
+	 */
+	public function invalidate(string $token) {
+		/* @var $qb IQueryBuilder */
+		$qb = $this->db->getQueryBuilder();
+		$qb->delete('authtoken')
+			->where($qb->expr()->eq('token', $qb->createNamedParameter($token)))
+			->andWhere($qb->expr()->eq('version', $qb->createNamedParameter(2, IQueryBuilder::PARAM_INT)))
+			->execute();
+	}
+
+	/**
+	 * @param int $olderThan
+	 * @param int $remember
+	 */
+	public function invalidateOld(int $olderThan, int $remember = IToken::DO_NOT_REMEMBER) {
+		/* @var $qb IQueryBuilder */
+		$qb = $this->db->getQueryBuilder();
+		$qb->delete('authtoken')
+			->where($qb->expr()->lt('last_activity', $qb->createNamedParameter($olderThan, IQueryBuilder::PARAM_INT)))
+			->andWhere($qb->expr()->eq('type', $qb->createNamedParameter(IToken::TEMPORARY_TOKEN, IQueryBuilder::PARAM_INT)))
+			->andWhere($qb->expr()->eq('remember', $qb->createNamedParameter($remember, IQueryBuilder::PARAM_INT)))
+			->andWhere($qb->expr()->eq('version', $qb->createNamedParameter(2, IQueryBuilder::PARAM_INT)))
+			->execute();
+	}
+
+	/**
+	 * Get the user UID for the given token
+	 *
+	 * @throws DoesNotExistException
+	 */
+	public function getToken(string $token): PublicKeyToken {
+		/* @var $qb IQueryBuilder */
+		$qb = $this->db->getQueryBuilder();
+		$result = $qb->select('*')
+			->from('authtoken')
+			->where($qb->expr()->eq('token', $qb->createNamedParameter($token)))
+			->andWhere($qb->expr()->eq('version', $qb->createNamedParameter(2, IQueryBuilder::PARAM_INT)))
+			->execute();
+
+		$data = $result->fetch();
+		$result->closeCursor();
+		if ($data === false) {
+			throw new DoesNotExistException('token does not exist');
+		}
+		return PublicKeyToken::fromRow($data);
+	}
+
+	/**
+	 * Get the token for $id
+	 *
+	 * @throws DoesNotExistException
+	 */
+	public function getTokenById(int $id): PublicKeyToken {
+		/* @var $qb IQueryBuilder */
+		$qb = $this->db->getQueryBuilder();
+		$result = $qb->select('*')
+			->from('authtoken')
+			->where($qb->expr()->eq('id', $qb->createNamedParameter($id)))
+			->andWhere($qb->expr()->eq('version', $qb->createNamedParameter(2, IQueryBuilder::PARAM_INT)))
+			->execute();
+
+		$data = $result->fetch();
+		$result->closeCursor();
+		if ($data === false) {
+			throw new DoesNotExistException('token does not exist');
+		}
+		return PublicKeyToken::fromRow($data);
+	}
+
+	/**
+	 * Get all tokens of a user
+	 *
+	 * The provider may limit the number of result rows in case of an abuse
+	 * where a high number of (session) tokens is generated
+	 *
+	 * @param IUser $user
+	 * @return DefaultToken[]
+	 */
+	public function getTokenByUser(IUser $user): array {
+		/* @var $qb IQueryBuilder */
+		$qb = $this->db->getQueryBuilder();
+		$qb->select('*')
+			->from('authtoken')
+			->where($qb->expr()->eq('uid', $qb->createNamedParameter($user->getUID())))
+			->andWhere($qb->expr()->eq('version', $qb->createNamedParameter(2, IQueryBuilder::PARAM_INT)))
+			->setMaxResults(1000);
+		$result = $qb->execute();
+		$data = $result->fetchAll();
+		$result->closeCursor();
+
+		$entities = array_map(function ($row) {
+			return PublicKeyToken::fromRow($row);
+		}, $data);
+
+		return $entities;
+	}
+
+	/**
+	 * @param IUser $user
+	 * @param int $id
+	 */
+	public function deleteById(IUser $user, int $id) {
+		/* @var $qb IQueryBuilder */
+		$qb = $this->db->getQueryBuilder();
+		$qb->delete('authtoken')
+			->where($qb->expr()->eq('id', $qb->createNamedParameter($id)))
+			->andWhere($qb->expr()->eq('uid', $qb->createNamedParameter($user->getUID())))
+			->andWhere($qb->expr()->eq('version', $qb->createNamedParameter(2, IQueryBuilder::PARAM_INT)));
+		$qb->execute();
+	}
+
+	/**
+	 * delete all auth token which belong to a specific client if the client was deleted
+	 *
+	 * @param string $name
+	 */
+	public function deleteByName(string $name) {
+		$qb = $this->db->getQueryBuilder();
+		$qb->delete('authtoken')
+			->where($qb->expr()->eq('name', $qb->createNamedParameter($name), IQueryBuilder::PARAM_STR))
+			->andWhere($qb->expr()->eq('version', $qb->createNamedParameter(2, IQueryBuilder::PARAM_INT)));
+		$qb->execute();
+	}
+
+}
diff --git a/lib/private/Authentication/Token/PublicKeyTokenProvider.php b/lib/private/Authentication/Token/PublicKeyTokenProvider.php
new file mode 100644
index 0000000000000000000000000000000000000000..d7e9038a07668b06acf74f88b69288e4f69da9df
--- /dev/null
+++ b/lib/private/Authentication/Token/PublicKeyTokenProvider.php
@@ -0,0 +1,265 @@
+<?php
+declare(strict_types=1);
+/**
+ * @copyright Copyright 2018, Roeland Jago Douma <roeland@famdouma.nl>
+ *
+ * @author Roeland Jago Douma <roeland@famdouma.nl>
+ *
+ * @license AGPL-3.0
+ *
+ * This code is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License, version 3,
+ * as published by the Free Software Foundation.
+ *
+ * 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, version 3,
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>
+ *
+ */
+
+namespace OC\Authentication\Token;
+
+use OC\Authentication\Exceptions\InvalidTokenException;
+use OC\Authentication\Exceptions\PasswordlessTokenException;
+use OCP\AppFramework\Db\DoesNotExistException;
+use OCP\AppFramework\Utility\ITimeFactory;
+use OCP\IConfig;
+use OCP\ILogger;
+use OCP\IUser;
+use OCP\Security\ICrypto;
+
+class PublicKeyTokenProvider implements IProvider {
+	/** @var PublicKeyTokenMapper */
+	private $mapper;
+
+	/** @var ICrypto */
+	private $crypto;
+
+	/** @var IConfig */
+	private $config;
+
+	/** @var ILogger $logger */
+	private $logger;
+
+	/** @var ITimeFactory $time */
+	private $time;
+
+	public function __construct(PublicKeyTokenMapper $mapper,
+								ICrypto $crypto,
+								IConfig $config,
+								ILogger $logger,
+								ITimeFactory $time) {
+		$this->mapper = $mapper;
+		$this->crypto = $crypto;
+		$this->config = $config;
+		$this->logger = $logger;
+		$this->time = $time;
+	}
+
+	public function generateToken(string $token,
+								  string $uid,
+								  string $loginName,
+								  $password,
+								  string $name,
+								  int $type = IToken::TEMPORARY_TOKEN,
+								  int $remember = IToken::DO_NOT_REMEMBER): IToken {
+		$dbToken = new PublicKeyToken();
+		$dbToken->setUid($uid);
+		$dbToken->setLoginName($loginName);
+
+		$config = [
+			'digest_alg' => 'sha512',
+			'private_key_bits' => 2048,
+		];
+
+		// Generate new key
+		$res = openssl_pkey_new($config);
+		openssl_pkey_export($res, $privateKey);
+
+		// Extract the public key from $res to $pubKey
+		$publicKey = openssl_pkey_get_details($res);
+		$publicKey = $publicKey['key'];
+
+		$dbToken->setPublicKey($publicKey);
+		$dbToken->setPrivateKey($this->encrypt($privateKey, $token));
+
+		if (!is_null($password)) {
+			$dbToken->setPassword($this->encryptPassword($password, $publicKey));
+		}
+
+		$dbToken->setName($name);
+		$dbToken->setToken($this->hashToken($token));
+		$dbToken->setType($type);
+		$dbToken->setRemember($remember);
+		$dbToken->setLastActivity($this->time->getTime());
+		$dbToken->setLastCheck($this->time->getTime());
+
+		$this->mapper->insert($dbToken);
+
+		return $dbToken;
+	}
+
+	public function getToken(string $tokenId): IToken {
+		try {
+			$token = $this->mapper->getToken($this->hashToken($tokenId));
+		} catch (DoesNotExistException $ex) {
+			throw new InvalidTokenException();
+		}
+
+		if ($token->getExpires() !== null && $token->getExpires() < $this->time->getTime()) {
+			throw new ExpiredTokenException($token);
+		}
+
+		return $token;
+	}
+
+	public function getTokenById(int $tokenId): IToken {
+		try {
+			$token = $this->mapper->getTokenById($tokenId);
+		} catch (DoesNotExistException $ex) {
+			throw new InvalidTokenException();
+		}
+
+		if ($token->getExpires() !== null && $token->getExpires() < $this->time->getTime()) {
+			throw new ExpiredTokenException($token);
+		}
+
+		return $token;
+	}
+
+	public function renewSessionToken(string $oldSessionId, string $sessionId) {
+		$token = $this->getToken($oldSessionId);
+
+		$password = null;
+		if (!is_null($token->getPassword())) {
+			$password = $this->decryptPassword($token->getPassword(), $oldSessionId);
+		}
+
+		$this->generateToken(
+			$sessionId,
+			$token->getUID(),
+			$token->getLoginName(),
+			$password,
+			$token->getName(),
+			IToken::TEMPORARY_TOKEN,
+			$token->getRemember()
+		);
+
+		$this->mapper->delete($token);
+	}
+
+	public function invalidateToken(string $token) {
+		$this->mapper->invalidate($this->hashToken($token));
+	}
+
+	public function invalidateTokenById(IUser $user, int $id) {
+		$this->mapper->deleteById($user, $id);
+	}
+
+	public function invalidateOldTokens() {
+		$olderThan = $this->time->getTime() - (int) $this->config->getSystemValue('session_lifetime', 60 * 60 * 24);
+		$this->logger->debug('Invalidating session tokens older than ' . date('c', $olderThan), ['app' => 'cron']);
+		$this->mapper->invalidateOld($olderThan, IToken::DO_NOT_REMEMBER);
+		$rememberThreshold = $this->time->getTime() - (int) $this->config->getSystemValue('remember_login_cookie_lifetime', 60 * 60 * 24 * 15);
+		$this->logger->debug('Invalidating remembered session tokens older than ' . date('c', $rememberThreshold), ['app' => 'cron']);
+		$this->mapper->invalidateOld($rememberThreshold, IToken::REMEMBER);
+	}
+
+	public function updateToken(IToken $token) {
+		if (!($token instanceof PublicKeyToken)) {
+			throw new InvalidTokenException();
+		}
+		$this->mapper->update($token);
+	}
+
+	public function updateTokenActivity(IToken $token) {
+		if (!($token instanceof PublicKeyToken)) {
+			throw new InvalidTokenException();
+		}
+		/** @var DefaultToken $token */
+		$now = $this->time->getTime();
+		if ($token->getLastActivity() < ($now - 60)) {
+			// Update token only once per minute
+			$token->setLastActivity($now);
+			$this->mapper->update($token);
+		}
+	}
+
+	public function getTokenByUser(IUser $user): array {
+		return $this->mapper->getTokenByUser($user);
+	}
+
+	public function getPassword(IToken $token, string $tokenId): string {
+		if (!($token instanceof PublicKeyToken)) {
+			throw new InvalidTokenException();
+		}
+
+		// Decrypt private key with tokenId
+		$privateKey = $this->decrypt($token->getPrivateKey(), $tokenId);
+
+		// Decrypt password with private key
+		return $this->decryptPassword($token->getPassword(), $privateKey);
+	}
+
+	public function setPassword(IToken $token, string $tokenId, string $password) {
+		// Kill all temp tokens except the current token
+
+		// Update pass for all permanent tokens by rencrypting
+	}
+
+	public function rotate(IToken $token, string $oldTokenId, string $newTokenId): IToken {
+		if (!($token instanceof PublicKeyToken)) {
+			throw new InvalidTokenException();
+		}
+
+		// Decrypt private key with oldTokenId
+		$privateKey = $this->decrypt($token->getPrivateKey(), $oldTokenId);
+		// Encrypt with the new token
+		$token->setPrivateKey($this->encrypt($privateKey, $newTokenId));
+
+		$token->setToken($this->hashToken($newTokenId));
+		$this->updateToken($token);
+
+		return $token;
+	}
+
+	private function encrypt(string $plaintext, string $token): string {
+		$secret = $this->config->getSystemValue('secret');
+		return $this->crypto->encrypt($plaintext, $token . $secret);
+	}
+
+	/**
+	 * @throws InvalidTokenException
+	 */
+	private function decrypt(string $cipherText, string $token): string {
+		$secret = $this->config->getSystemValue('secret');
+		try {
+			return $this->crypto->decrypt($cipherText, $token . $secret);
+		} catch (\Exception $ex) {
+			// Delete the invalid token
+			$this->invalidateToken($token);
+			throw new InvalidTokenException();
+		}
+	}
+
+	private function encryptPassword(string $password, string $publicKey): string {
+		openssl_public_encrypt($password, $encryptedPassword, $publicKey, OPENSSL_PKCS1_OAEP_PADDING);
+
+		return $encryptedPassword;
+	}
+
+	private function decryptPassword(string $encryptedPassword, string $privateKey): string {
+		openssl_private_decrypt($encryptedPassword, $password, $privateKey, OPENSSL_PKCS1_OAEP_PADDING);
+
+		return $password;
+	}
+
+	private function hashToken(string $token): string {
+		$secret = $this->config->getSystemValue('secret');
+		return hash('sha512', $token . $secret);
+	}
+}