A real "Stay signed in": keep the connection

Instead of trusting the php session, it uses a cookie. The php session
sooner or later is distroyed if not used. It depends upon the server
settings. Using a cookie ensures that one really stays signed in.

Dev notes: I wanted to avoid merge conflicts, stay with the main
developper standards and keep the "index.php" in one file. That's why
the code may not be that nice. My own dev level my also explain.

Author: Sbgodin

index.php

@@ -37,6 +37,8 @@
 define('shaarli_version','0.0.41 beta');
 define('PHPPREFIX','<?php /* '); // Prefix to encapsulate data in php code.
 define('PHPSUFFIX',' */ ?>'); // Suffix to encapsulate data in php code.
+// http://server.com/x/shaarli --> /shaarli/
+define('WEB_PATH', substr($_SERVER["REQUEST_URI"], 0, 1+strrpos($_SERVER["REQUEST_URI"], '/', 0)));
 
 // Force cookie path (but do not change lifetime)
 $cookie=session_get_cookie_params();
@@ -110,6 +112,8 @@ function stripslashes_deep($value) { $value = is_array($value) ? array_map('stri
 
 require $GLOBALS['config']['CONFIG_FILE'];  // Read login/password hash into $GLOBALS.
 
+// a token depending of deployment salt, user password, and the current ip
+define('STAY_SIGNED_IN_TOKEN', sha1($GLOBALS['hash'].$_SERVER["REMOTE_ADDR"].$GLOBALS['salt']));
 
 autoLocale(); // Sniff browser language and set date format accordingly.
 header('Content-Type: text/html; charset=utf-8'); // We use UTF-8 for proper international characters handling.
@@ -294,16 +298,20 @@ function allIPs()
     return $ip;
 }
 
+function fillSessionInfo() {
+	$_SESSION['uid'] = sha1(uniqid('',true).'_'.mt_rand()); // generate unique random number (different than phpsessionid)
+	$_SESSION['ip']=allIPs();                // We store IP address(es) of the client to make sure session is not hijacked.
+	$_SESSION['username']=$GLOBALS['login'];
+	$_SESSION['expires_on']=time()+INACTIVITY_TIMEOUT;  // Set session expiration.
+}
+
 // Check that user/password is correct.
 function check_auth($login,$password)
 {
     $hash = sha1($password.$login.$GLOBALS['salt']);
     if ($login==$GLOBALS['login'] && $hash==$GLOBALS['hash'])
     {   // Login/password is correct.
-        $_SESSION['uid'] = sha1(uniqid('',true).'_'.mt_rand()); // generate unique random number (different than phpsessionid)
-        $_SESSION['ip']=allIPs();                // We store IP address(es) of the client to make sure session is not hijacked.
-        $_SESSION['username']=$login;
-        $_SESSION['expires_on']=time()+INACTIVITY_TIMEOUT;  // Set session expiration.
+		fillSessionInfo();
         logm('Login successful');
         return True;
     }
@@ -318,6 +326,11 @@ function isLoggedIn()
 
     if (!isset($GLOBALS['login'])) return false;  // Shaarli is not configured yet.
 
+	if (@$_COOKIE['shaarli_staySignedIn']===STAY_SIGNED_IN_TOKEN)
+	{
+		fillSessionInfo();
+		return true;
+	}
     // If session does not exist on server side, or IP address has changed, or session has expired, logout.
     if (empty($_SESSION['uid']) || ($GLOBALS['disablesessionprotection']==false && $_SESSION['ip']!=allIPs()) || time()>=$_SESSION['expires_on'])
     {
@@ -331,7 +344,9 @@ function isLoggedIn()
 }
 
 // Force logout.
-function logout() { if (isset($_SESSION)) { unset($_SESSION['uid']); unset($_SESSION['ip']); unset($_SESSION['username']); unset($_SESSION['privateonly']); }  }
+function logout() { if (isset($_SESSION)) { unset($_SESSION['uid']); unset($_SESSION['ip']); unset($_SESSION['username']); unset($_SESSION['privateonly']); }  
+setcookie('shaarli_staySignedIn', FALSE, 0, WEB_PATH);
+}
 
 
 // ------------------------------------------------------------------------------------------
@@ -393,6 +408,7 @@ function ban_canLogin()
         // If user wants to keep the session cookie even after the browser closes:
         if (!empty($_POST['longlastingsession']))
         {
+			setcookie('shaarli_staySignedIn', STAY_SIGNED_IN_TOKEN, time()+31536000, WEB_PATH);
             $_SESSION['longlastingsession']=31536000;  // (31536000 seconds = 1 year)
             $_SESSION['expires_on']=time()+$_SESSION['longlastingsession'];  // Set session expiration on server-side.