1 files changed, 199 insertions, 0 deletions

diff --git a/application/security/SessionManager.php b/application/security/SessionManager.php
new file mode 100644
index 00000000..b8b8ab8d
--- /dev/null
+++ b/application/security/SessionManager.php
@@ -0,0 +1,199 @@
+<?php
+namespace Shaarli\Security;
+
+use Shaarli\Config\ConfigManager;
+
+/**
+ * Manages the server-side session
+ */
+class SessionManager
+{
+    /** @var int Session expiration timeout, in seconds */
+    public static $SHORT_TIMEOUT = 3600;    // 1 hour
+
+    /** @var int Session expiration timeout, in seconds */
+    public static $LONG_TIMEOUT = 31536000; // 1 year
+
+    /** @var array Local reference to the global $_SESSION array */
+    protected $session = [];
+
+    /** @var ConfigManager Configuration Manager instance **/
+    protected $conf = null;
+
+    /** @var bool Whether the user should stay signed in (LONG_TIMEOUT) */
+    protected $staySignedIn = false;
+
+    /**
+     * Constructor
+     *
+     * @param array         $session The $_SESSION array (reference)
+     * @param ConfigManager $conf    ConfigManager instance
+     */
+    public function __construct(& $session, $conf)
+    {
+        $this->session = &$session;
+        $this->conf = $conf;
+    }
+
+    /**
+     * Define whether the user should stay signed in across browser sessions
+     *
+     * @param bool $staySignedIn Keep the user signed in
+     */
+    public function setStaySignedIn($staySignedIn)
+    {
+        $this->staySignedIn = $staySignedIn;
+    }
+
+    /**
+     * Generates a session token
+     *
+     * @return string token
+     */
+    public function generateToken()
+    {
+        $token = sha1(uniqid('', true) .'_'. mt_rand() . $this->conf->get('credentials.salt'));
+        $this->session['tokens'][$token] = 1;
+        return $token;
+    }
+
+    /**
+     * Checks the validity of a session token, and destroys it afterwards
+     *
+     * @param string $token The token to check
+     *
+     * @return bool true if the token is valid, else false
+     */
+    public function checkToken($token)
+    {
+        if (! isset($this->session['tokens'][$token])) {
+            // the token is wrong, or has already been used
+            return false;
+        }
+
+        // destroy the token to prevent future use
+        unset($this->session['tokens'][$token]);
+        return true;
+    }
+
+    /**
+     * Validate session ID to prevent Full Path Disclosure.
+     *
+     * See #298.
+     * The session ID's format depends on the hash algorithm set in PHP settings
+     *
+     * @param string $sessionId Session ID
+     *
+     * @return true if valid, false otherwise.
+     *
+     * @see http://php.net/manual/en/function.hash-algos.php
+     * @see http://php.net/manual/en/session.configuration.php
+     */
+    public static function checkId($sessionId)
+    {
+        if (empty($sessionId)) {
+            return false;
+        }
+
+        if (!$sessionId) {
+            return false;
+        }
+
+        if (!preg_match('/^[a-zA-Z0-9,-]{2,128}$/', $sessionId)) {
+            return false;
+        }
+
+        return true;
+    }
+
+    /**
+     * Store user login information after a successful login
+     *
+     * @param string $clientIpId Client IP address identifier
+     */
+    public function storeLoginInfo($clientIpId)
+    {
+        $this->session['ip'] = $clientIpId;
+        $this->session['username'] = $this->conf->get('credentials.login');
+        $this->extendTimeValidityBy(self::$SHORT_TIMEOUT);
+    }
+
+    /**
+     * Extend session validity
+     */
+    public function extendSession()
+    {
+        if ($this->staySignedIn) {
+            return $this->extendTimeValidityBy(self::$LONG_TIMEOUT);
+        }
+        return $this->extendTimeValidityBy(self::$SHORT_TIMEOUT);
+    }
+
+    /**
+     * Extend expiration time
+     *
+     * @param int $duration Expiration time extension (seconds)
+     *
+     * @return int New session expiration time
+     */
+    protected function extendTimeValidityBy($duration)
+    {
+        $expirationTime = time() + $duration;
+        $this->session['expires_on'] = $expirationTime;
+        return $expirationTime;
+    }
+
+    /**
+     * Logout a user by unsetting all login information
+     *
+     * See:
+     * - https://secure.php.net/manual/en/function.setcookie.php
+     */
+    public function logout()
+    {
+        if (isset($this->session)) {
+            unset($this->session['ip']);
+            unset($this->session['expires_on']);
+            unset($this->session['username']);
+            unset($this->session['visibility']);
+            unset($this->session['untaggedonly']);
+        }
+    }
+
+    /**
+     * Check whether the session has expired
+     *
+     * @param string $clientIpId Client IP address identifier
+     *
+     * @return bool true if the session has expired, false otherwise
+     */
+    public function hasSessionExpired()
+    {
+        if (empty($this->session['expires_on'])) {
+            return true;
+        }
+        if (time() >= $this->session['expires_on']) {
+            return true;
+        }
+        return false;
+    }
+
+    /**
+     * Check whether the client IP address has changed
+     *
+     * @param string $clientIpId Client IP address identifier
+     *
+     * @return bool true if the IP has changed, false if it has not, or
+     *              if session protection has been disabled
+     */
+    public function hasClientIpChanged($clientIpId)
+    {
+        if ($this->conf->get('security.session_protection_disabled') === true) {
+            return false;
+        }
+        if (isset($this->session['ip']) && $this->session['ip'] === $clientIpId) {
+            return false;
+        }
+        return true;
+    }
+}