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-rw-r--r--lib/private/security/csrf/csrftoken.php69
-rw-r--r--lib/private/security/csrf/csrftokengenerator.php52
-rw-r--r--lib/private/security/csrf/csrftokenmanager.php97
-rw-r--r--lib/private/security/csrf/tokenstorage/sessionstorage.php80
4 files changed, 298 insertions, 0 deletions
diff --git a/lib/private/security/csrf/csrftoken.php b/lib/private/security/csrf/csrftoken.php
new file mode 100644
index 00000000000..4524d0db6e6
--- /dev/null
+++ b/lib/private/security/csrf/csrftoken.php
@@ -0,0 +1,69 @@
+<?php
+/**
+ * @author Lukas Reschke <lukas@owncloud.com>
+ *
+ * @copyright Copyright (c) 2016, ownCloud, Inc.
+ * @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\Security\CSRF;
+
+/**
+ * Class CsrfToken represents the stored or provided CSRF token. To mitigate
+ * BREACH alike vulnerabilities the token is returned in an encrypted value as
+ * well in an unencrypted value. For display measures to the user always the
+ * unencrypted one should be chosen.
+ *
+ * @package OC\Security\CSRF
+ */
+class CsrfToken {
+ /** @var string */
+ private $value;
+
+ /**
+ * @param string $value Value of the token. Can be encrypted or not encrypted.
+ */
+ public function __construct($value) {
+ $this->value = $value;
+ }
+
+ /**
+ * Encrypted value of the token. This is used to mitigate BREACH alike
+ * vulnerabilities. For display measures do use this functionality.
+ *
+ * @return string
+ */
+ public function getEncryptedValue() {
+ $sharedSecret = base64_encode(random_bytes(strlen($this->value)));
+ return base64_encode($this->value ^ $sharedSecret) .':'.$sharedSecret;
+ }
+
+ /**
+ * The unencrypted value of the token. Used for decrypting an already
+ * encrypted token.
+ *
+ * @return int
+ */
+ public function getDecryptedValue() {
+ $token = explode(':', $this->value);
+ if (count($token) !== 2) {
+ return '';
+ }
+ $obfuscatedToken = $token[0];
+ $secret = $token[1];
+ return base64_decode($obfuscatedToken) ^ $secret;
+ }
+}
diff --git a/lib/private/security/csrf/csrftokengenerator.php b/lib/private/security/csrf/csrftokengenerator.php
new file mode 100644
index 00000000000..6ea71636d22
--- /dev/null
+++ b/lib/private/security/csrf/csrftokengenerator.php
@@ -0,0 +1,52 @@
+<?php
+/**
+ * @author Lukas Reschke <lukas@owncloud.com>
+ *
+ * @copyright Copyright (c) 2016, ownCloud, Inc.
+ * @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\Security\CSRF;
+
+use OCP\Security\ISecureRandom;
+
+/**
+ * Class CsrfTokenGenerator is used to generate a cryptographically secure
+ * pseudo-random number for the token.
+ *
+ * @package OC\Security\CSRF
+ */
+class CsrfTokenGenerator {
+ /** @var ISecureRandom */
+ private $random;
+
+ /**
+ * @param ISecureRandom $random
+ */
+ public function __construct(ISecureRandom $random) {
+ $this->random = $random;
+ }
+
+ /**
+ * Generate a new CSRF token.
+ *
+ * @param int $length Length of the token in characters.
+ * @return string
+ */
+ public function generateToken($length = 32) {
+ return $this->random->generate($length);
+ }
+}
diff --git a/lib/private/security/csrf/csrftokenmanager.php b/lib/private/security/csrf/csrftokenmanager.php
new file mode 100644
index 00000000000..8d1bf5c0819
--- /dev/null
+++ b/lib/private/security/csrf/csrftokenmanager.php
@@ -0,0 +1,97 @@
+<?php
+/**
+ * @author Lukas Reschke <lukas@owncloud.com>
+ *
+ * @copyright Copyright (c) 2016, ownCloud, Inc.
+ * @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\Security\CSRF;
+
+use OC\Security\CSRF\TokenStorage\SessionStorage;
+
+/**
+ * Class CsrfTokenManager is the manager for all CSRF token related activities.
+ *
+ * @package OC\Security\CSRF
+ */
+class CsrfTokenManager {
+ /** @var CsrfTokenGenerator */
+ private $tokenGenerator;
+ /** @var SessionStorage */
+ private $sessionStorage;
+
+ /**
+ * @param CsrfTokenGenerator $tokenGenerator
+ * @param SessionStorage $storageInterface
+ */
+ public function __construct(CsrfTokenGenerator $tokenGenerator,
+ SessionStorage $storageInterface) {
+ $this->tokenGenerator = $tokenGenerator;
+ $this->sessionStorage = $storageInterface;
+ }
+
+ /**
+ * Returns the current CSRF token, if none set it will create a new one.
+ *
+ * @return CsrfToken
+ */
+ public function getToken() {
+ if($this->sessionStorage->hasToken()) {
+ $value = $this->sessionStorage->getToken();
+ } else {
+ $value = $this->tokenGenerator->generateToken();
+ $this->sessionStorage->setToken($value);
+ }
+
+ return new CsrfToken($value);
+ }
+
+ /**
+ * Invalidates any current token and sets a new one.
+ *
+ * @return CsrfToken
+ */
+ public function refreshToken() {
+ $value = $this->tokenGenerator->generateToken();
+ $this->sessionStorage->setToken($value);
+ return new CsrfToken($value);
+ }
+
+ /**
+ * Remove the current token from the storage.
+ */
+ public function removeToken() {
+ $this->sessionStorage->removeToken();
+ }
+
+ /**
+ * Verifies whether the provided token is valid.
+ *
+ * @param CsrfToken $token
+ * @return bool
+ */
+ public function isTokenValid(CsrfToken $token) {
+ if(!$this->sessionStorage->hasToken()) {
+ return false;
+ }
+
+ return hash_equals(
+ $this->sessionStorage->getToken(),
+ $token->getDecryptedValue()
+ );
+ }
+}
diff --git a/lib/private/security/csrf/tokenstorage/sessionstorage.php b/lib/private/security/csrf/tokenstorage/sessionstorage.php
new file mode 100644
index 00000000000..e1c8c96e920
--- /dev/null
+++ b/lib/private/security/csrf/tokenstorage/sessionstorage.php
@@ -0,0 +1,80 @@
+<?php
+/**
+ * @author Lukas Reschke <lukas@owncloud.com>
+ *
+ * @copyright Copyright (c) 2016, ownCloud, Inc.
+ * @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\Security\CSRF\TokenStorage;
+
+use OCP\ISession;
+
+/**
+ * Class SessionStorage provides the session storage
+ *
+ * @package OC\Security\CSRF\TokenStorage
+ */
+class SessionStorage {
+ /** @var ISession */
+ private $session;
+
+ /**
+ * @param ISession $session
+ */
+ public function __construct(ISession $session) {
+ $this->session = $session;
+ }
+
+ /**
+ * Returns the current token or throws an exception if none is found.
+ *
+ * @return string
+ * @throws \Exception
+ */
+ public function getToken() {
+ $token = $this->session->get('requesttoken');
+ if(empty($token)) {
+ throw new \Exception('Session does not contain a requesttoken');
+ }
+
+ return $token;
+ }
+
+ /**
+ * Set the valid current token to $value.
+ *
+ * @param string $value
+ */
+ public function setToken($value) {
+ $this->session->set('requesttoken', $value);
+ }
+
+ /**
+ * Removes the current token.
+ */
+ public function removeToken() {
+ $this->session->remove('requesttoken');
+ }
+ /**
+ * Whether the storage has a storage.
+ *
+ * @return bool
+ */
+ public function hasToken() {
+ return $this->session->exists('requesttoken');
+ }
+}
generated by cgit v1.2.3 (git 2.39.1) at 2025-02-05 02:35:45 +0000