2 files changed, 417 insertions, 0 deletions

diff --git a/application/security/LoginManager.php b/application/security/LoginManager.php
new file mode 100644
index 00000000..e7b9b21e
--- /dev/null
+++ b/application/security/LoginManager.php
@@ -0,0 +1,238 @@
+<?php
+namespace Shaarli\Security;
+
+use Shaarli\Config\ConfigManager;
+
+/**
+ * User login management
+ */
+class LoginManager
+{
+    /** @var array A reference to the $_GLOBALS array */
+    protected $globals = [];
+
+    /** @var ConfigManager Configuration Manager instance **/
+    protected $configManager = null;
+
+    /** @var SessionManager Session Manager instance **/
+    protected $sessionManager = null;
+
+    /** @var string Path to the file containing IP bans */
+    protected $banFile = '';
+
+    /** @var bool Whether the user is logged in **/
+    protected $isLoggedIn = false;
+
+    /** @var bool Whether the Shaarli instance is open to public edition **/
+    protected $openShaarli = false;
+
+    /**
+     * Constructor
+     *
+     * @param array          $globals        The $GLOBALS array (reference)
+     * @param ConfigManager  $configManager  Configuration Manager instance
+     * @param SessionManager $sessionManager SessionManager instance
+     */
+    public function __construct(& $globals, $configManager, $sessionManager)
+    {
+        $this->globals = &$globals;
+        $this->configManager = $configManager;
+        $this->sessionManager = $sessionManager;
+        $this->banFile = $this->configManager->get('resource.ban_file', 'data/ipbans.php');
+        $this->readBanFile();
+        if ($this->configManager->get('security.open_shaarli')) {
+            $this->openShaarli = true;
+        }
+    }
+
+    /**
+     * Check user session state and validity (expiration)
+     *
+     * @param array  $cookie     The $_COOKIE array
+     * @param string $webPath    Path on the server in which the cookie will be available on
+     * @param string $clientIpId Client IP address identifier
+     * @param string $token      Session token
+     *
+     * @return bool true if the user session is valid, false otherwise
+     */
+    public function checkLoginState($cookie, $webPath, $clientIpId, $token)
+    {
+        if (! $this->configManager->exists('credentials.login')) {
+            // Shaarli is not configured yet
+            $this->isLoggedIn = false;
+            return;
+        }
+
+        if (isset($cookie[SessionManager::$LOGGED_IN_COOKIE])
+            && $cookie[SessionManager::$LOGGED_IN_COOKIE] === $token
+        ) {
+            $this->sessionManager->storeLoginInfo($clientIpId);
+            $this->isLoggedIn = true;
+        }
+
+        if ($this->sessionManager->hasSessionExpired()
+            || $this->sessionManager->hasClientIpChanged($clientIpId)
+        ) {
+            $this->sessionManager->logout($webPath);
+            $this->isLoggedIn = false;
+            return;
+        }
+
+        $this->sessionManager->extendSession();
+    }
+
+    /**
+     * Return whether the user is currently logged in
+     *
+     * @return true when the user is logged in, false otherwise
+     */
+    public function isLoggedIn()
+    {
+        if ($this->openShaarli) {
+            return true;
+        }
+        return $this->isLoggedIn;
+    }
+
+    /**
+     * Check user credentials are valid
+     *
+     * @param string $remoteIp   Remote client IP address
+     * @param string $clientIpId Client IP address identifier
+     * @param string $login      Username
+     * @param string $password   Password
+     *
+     * @return bool true if the provided credentials are valid, false otherwise
+     */
+    public function checkCredentials($remoteIp, $clientIpId, $login, $password)
+    {
+        $hash = sha1($password . $login . $this->configManager->get('credentials.salt'));
+
+        if ($login != $this->configManager->get('credentials.login')
+            || $hash != $this->configManager->get('credentials.hash')
+        ) {
+            logm(
+                $this->configManager->get('resource.log'),
+                $remoteIp,
+                'Login failed for user ' . $login
+            );
+            return false;
+        }
+
+        $this->sessionManager->storeLoginInfo($clientIpId);
+        logm(
+            $this->configManager->get('resource.log'),
+            $remoteIp,
+            'Login successful'
+        );
+        return true;
+    }
+
+    /**
+     * Read a file containing banned IPs
+     */
+    protected function readBanFile()
+    {
+        if (! file_exists($this->banFile)) {
+            return;
+        }
+        include $this->banFile;
+    }
+
+    /**
+     * Write the banned IPs to a file
+     */
+    protected function writeBanFile()
+    {
+        if (! array_key_exists('IPBANS', $this->globals)) {
+            return;
+        }
+        file_put_contents(
+            $this->banFile,
+            "<?php\n\$GLOBALS['IPBANS']=" . var_export($this->globals['IPBANS'], true) . ";\n?>"
+        );
+    }
+
+    /**
+     * Handle a failed login and ban the IP after too many failed attempts
+     *
+     * @param array $server The $_SERVER array
+     */
+    public function handleFailedLogin($server)
+    {
+        $ip = $server['REMOTE_ADDR'];
+        $trusted = $this->configManager->get('security.trusted_proxies', []);
+
+        if (in_array($ip, $trusted)) {
+            $ip = getIpAddressFromProxy($server, $trusted);
+            if (! $ip) {
+                // the IP is behind a trusted forward proxy, but is not forwarded
+                // in the HTTP headers, so we do nothing
+                return;
+            }
+        }
+
+        // increment the fail count for this IP
+        if (isset($this->globals['IPBANS']['FAILURES'][$ip])) {
+            $this->globals['IPBANS']['FAILURES'][$ip]++;
+        } else {
+            $this->globals['IPBANS']['FAILURES'][$ip] = 1;
+        }
+
+        if ($this->globals['IPBANS']['FAILURES'][$ip] >= $this->configManager->get('security.ban_after')) {
+            $this->globals['IPBANS']['BANS'][$ip] = time() + $this->configManager->get('security.ban_duration', 1800);
+            logm(
+                $this->configManager->get('resource.log'),
+                $server['REMOTE_ADDR'],
+                'IP address banned from login'
+            );
+        }
+        $this->writeBanFile();
+    }
+
+    /**
+     * Handle a successful login
+     *
+     * @param array $server The $_SERVER array
+     */
+    public function handleSuccessfulLogin($server)
+    {
+        $ip = $server['REMOTE_ADDR'];
+        // FIXME unban when behind a trusted proxy?
+
+        unset($this->globals['IPBANS']['FAILURES'][$ip]);
+        unset($this->globals['IPBANS']['BANS'][$ip]);
+
+        $this->writeBanFile();
+    }
+
+    /**
+     * Check if the user can login from this IP
+     *
+     * @param array $server The $_SERVER array
+     *
+     * @return bool true if the user is allowed to login
+     */
+    public function canLogin($server)
+    {
+        $ip = $server['REMOTE_ADDR'];
+
+        if (! isset($this->globals['IPBANS']['BANS'][$ip])) {
+            // the user is not banned
+            return true;
+        }
+
+        if ($this->globals['IPBANS']['BANS'][$ip] > time()) {
+            // the user is still banned
+            return false;
+        }
+
+        // the ban has expired, the user can attempt to log in again
+        logm($this->configManager->get('resource.log'), $server['REMOTE_ADDR'], 'Ban lifted.');
+        unset($this->globals['IPBANS']['FAILURES'][$ip]);
+        unset($this->globals['IPBANS']['BANS'][$ip]);
+
+        $this->writeBanFile();
+        return true;
+    }
+}
diff --git a/application/security/SessionManager.php b/application/security/SessionManager.php
new file mode 100644
index 00000000..6f004b24
--- /dev/null
+++ b/application/security/SessionManager.php
@@ -0,0 +1,179 @@
+<?php
+namespace Shaarli\Security;
+
+use Shaarli\Config\ConfigManager;
+
+/**
+ * Manages the server-side session
+ */
+class SessionManager
+{
+    /** @var int Session expiration timeout, in seconds */
+    public static $INACTIVITY_TIMEOUT = 3600;
+
+    /** @var string Name of the cookie set after logging in **/
+    public static $LOGGED_IN_COOKIE = 'shaarli_staySignedIn';
+
+    /** @var array Local reference to the global $_SESSION array */
+    protected $session = [];
+
+    /** @var ConfigManager Configuration Manager instance **/
+    protected $conf = null;
+
+    /**
+     * Constructor
+     *
+     * @param array         $session The $_SESSION array (reference)
+     * @param ConfigManager $conf    ConfigManager instance
+     */
+    public function __construct(& $session, $conf)
+    {
+        $this->session = &$session;
+        $this->conf = $conf;
+    }
+
+    /**
+     * 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)
+    {
+        // Generate unique random number (different than phpsessionid)
+        $this->session['uid'] = sha1(uniqid('', true) . '_' . mt_rand());
+        $this->session['ip'] = $clientIpId;
+        $this->session['username'] = $this->conf->get('credentials.login');
+        $this->session['expires_on'] = time() + self::$INACTIVITY_TIMEOUT;
+    }
+
+    /**
+     * Extend session validity
+     */
+    public function extendSession()
+    {
+        if (! empty($this->session['longlastingsession'])) {
+            // "Stay signed in" is enabled
+            $this->session['expires_on'] = time() + $this->session['longlastingsession'];
+            return;
+        }
+        $this->session['expires_on'] = time() + self::$INACTIVITY_TIMEOUT;
+    }
+
+    /**
+     * Logout a user by unsetting all login information
+     *
+     * See:
+     * - https://secure.php.net/manual/en/function.setcookie.php
+     *
+     * @param string $webPath path on the server in which the cookie will be available on
+     */
+    public function logout($webPath)
+    {
+        if (isset($this->session)) {
+            unset($this->session['uid']);
+            unset($this->session['ip']);
+            unset($this->session['username']);
+            unset($this->session['visibility']);
+            unset($this->session['untaggedonly']);
+        }
+        setcookie(self::$LOGGED_IN_COOKIE, 'false', 0, $webPath);
+    }
+
+    /**
+     * 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['uid'])) {
+            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 ($this->conf->get('security.session_protection_disabled') === true) {
+            return false;
+        }
+        if ($this->session['ip'] == $clientIpId) {
+            return false;
+        }
+        return true;
+    }
+}