From 9050e76d955e06a5e5ed9b4b1c444bdf03699ba0 Mon Sep 17 00:00:00 2001
From: Roeland Jago Douma <rullzer@owncloud.com>
Date: Thu, 14 Apr 2016 19:21:18 +0200
Subject: Move \OC\Security to PSR-4

---
 lib/private/Security/CSRF/CsrfToken.php | 69 +++++++++++++++++++++++++++++++++
 1 file changed, 69 insertions(+)
 create mode 100644 lib/private/Security/CSRF/CsrfToken.php

(limited to 'lib/private/Security/CSRF/CsrfToken.php')

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;
+	}
+}
-- 
cgit v1.2.3