implement rememberme functionality

Added a checkbox on login or register to remember the current user. If
the login is successful, this sets a cookie with a random code (saved
in the DB). If they come back, and they aren't logged in "normally",
we check to see if they have a rememberme cookie. If so, we log them
in.

However, they can't change settings -- cookie theft is too prevalent.
So we mark a session as having a "real" (password or OpenID) login, or
not. In settings pages, we check to see if the login is "real", and if
not, we redirect to the login page.

darcs-hash:20080624025234-34904-ad20001bf35bf41fcb63a0c357fd929aacc55fdb.gz

actions/finishopenidlogin.php

@@ -130,6 +130,7 @@ class FinishopenidloginAction extends Action {
 				oid_set_last($display);
 				oid_update_user($user, $sreg);
 				common_set_user($user->nickname);
+				common_real_login(true);
 				$this->go_home($user->nickname);
 			} else {
 				$this->save_values($display, $canonical, $sreg);
@@ -253,6 +254,7 @@ class FinishopenidloginAction extends Action {
 		
 		oid_set_last($display);
 		common_set_user($user->nickname);
+		common_real_login(true);
 		common_redirect(common_local_url('showstream', array('nickname' => $user->nickname)));
 	}
 	
@@ -287,6 +289,7 @@ class FinishopenidloginAction extends Action {
 		oid_update_user($user, $sreg);
 		oid_set_last($display);
 		common_set_user($user->nickname);
+		common_real_login(true);
 		$this->go_home($user->nickname);
 	}
 	

actions/login.php

@@ -43,6 +43,10 @@ class LoginAction extends Action {
 				common_server_error(_t('Error setting user.'));
 				return;
 			}
+			common_real_login(true);
+			if ($this->boolean('rememberme')) {
+				common_rememberme();
+			}
 			# success!
 			$url = common_get_returnto();
 			if ($url) {
@@ -66,6 +70,9 @@ class LoginAction extends Action {
 										   'action' => common_local_url('login')));
 		common_input('nickname', _t('Nickname'));
 		common_password('password', _t('Password'));
+		common_checkbox('rememberme', _t('Remember me'),
+		                _t('Automatically login in the future; ' . 
+		                   'not for shared computers!'));
 		common_submit('submit', _t('Login'));
 		common_element_end('form');
 		common_show_footer();

actions/logout.php

@@ -27,8 +27,9 @@ class LogoutAction extends Action {
 		if (!common_logged_in()) {
 			common_user_error(_t('Not logged in.'));
 		} else {
-			oid_clear_last();
 			common_set_user(NULL);
+			common_real_login(false); # not logged in
+			common_forget_me(); # don't log back in!
 			common_redirect(common_local_url('public'));
 		}
 	}

actions/register.php

@@ -69,6 +69,10 @@ class RegisterAction extends Action {
 				common_server_error(_t('Error setting user.'));
 				return;
 			}
+			common_real_login(true);
+			if ($this->boolean('rememberme')) {
+				common_rememberme();
+			}
 			common_redirect(common_local_url('profilesettings'));
 		} else {
 			$this->show_form(_t('Invalid username or password.'));
@@ -170,6 +174,9 @@ class RegisterAction extends Action {
 						_t('Same as password above'));
 		common_input('email', _t('Email'), NULL,
 					 _t('Used only for updates, announcements, and password recovery'));
+		common_checkbox('rememberme', _t('Remember me'),
+		                _t('Automatically login in the future; ' . 
+		                   'not for shared computers!'));
 		common_element_start('p');
 		common_element('input', array('type' => 'checkbox',
 									  'id' => 'license',

lib/common.php

@@ -90,3 +90,4 @@ require_once(INSTALLDIR.'/classes/Remote_profile.php');
 require_once(INSTALLDIR.'/classes/Subscription.php');
 require_once(INSTALLDIR.'/classes/User.php');
 require_once(INSTALLDIR.'/classes/Confirm_address.php');
+require_once(INSTALLDIR.'/classes/Remember_me.php');

lib/openid.php

@@ -53,21 +53,9 @@ function oid_clear_last() {
 }
 
 function oid_set_last($openid_url) {
-	
-	$path = common_config('site', 'path');
-	$server = common_config('site', 'server');
-
-	if ($path && ($path != '/')) {
-		$cookiepath = '/' . $path . '/';
-	} else {
-		$cookiepath = '/';
-	}
-	
-	setcookie(OPENID_COOKIE_KEY,
+	common_set_cookie(OPENID_COOKIE_KEY,
 			         $openid_url,
-			  time() + OPENID_COOKIE_EXPIRY,
-			  $cookiepath,
-			  $server);
+			         time() + OPENID_COOKIE_EXPIRY);
 }
 
 function oid_get_last() {

lib/settingsaction.php

@@ -26,6 +26,12 @@ class SettingsAction extends Action {
         if (!common_logged_in()) {
             common_user_error(_t('Not logged in.'));
             return;
+        } else if (!common_is_real_login()) {
+        	# Cookie theft means that automatic logins can't
+        	# change important settings or see private info, and
+        	# _all_ our settings are important
+            common_set_returnto($this->self_url());
+            common_redirect(common_local_url('login'));
         } else if ($_SERVER['REQUEST_METHOD'] == 'POST') {
             $this->handle_post();
         } else {

lib/util.php

@@ -432,16 +432,106 @@ function common_set_user($nickname) {
 	return false;
 }
 
-# who is the current user?
-function common_current_user() {
-	common_ensure_session();
-	$id = $_SESSION['userid'];
-	if ($id) {
-		$user = User::staticGet($id);
+function commmon_set_cookie($key, $value, $expiration=0) {
+	$path = common_config('site', 'path');
+	$server = common_config('site', 'server');
+
+	if ($path && ($path != '/')) {
+		$cookiepath = '/' . $path . '/';
+	} else {
+		$cookiepath = '/';
+	}
+	return setcookie($key,
+	                 $value,
+	          		 $expiration,
+			  		 $cookiepath,
+			  	     $server);
+}
+
+define('REMEMBERME', 'rememberme');
+define('REMEMBERME_EXPIRY', round(30 * 24 * 60 * 60));
+
+function common_rememberme() {
+	$user = common_current_user();
+	if (!$user) {
+		return false;
+	}
+	$rm = new Remember_me();
+	$rm->code = common_good_rand(16);
+	$rm->user = $user->id();
+	if (!$rm->insert) {
+		common_log_db_error($rm, 'INSERT', __FILE__);
+		return false;
+	}
+	common_set_cookie(REMEMBERME,
+					  $rm->user . ':' . $rm->code,
+					  time() + REMEMBERME_EXPIRY);
+}
+
+function common_remembered_user() {
+	$user = NULL;
+	# Try to remember
+	$packed = $_COOKIE[REMEMBERME];
+	if ($packed) {
+		list($id, $code) = explode(':', $packed);
+		if ($id && $code) {
+			$rm = Remember_me::staticGet($code);
+			if ($rm && $rm->id == $id) {
+				$user = User::staticGet($rm->id);
+				if ($user) {
+					# successful!
+					$result = $rm->delete();
+					if (!$result) {
+						common_log_db_error($rm, 'DELETE', __FILE__);
+						$user = NULL;
+					} else {
+						common_set_user($user);
+						common_real_login(false);
+						common_rememberme();
+					}
+				}
+			}
+		}
 	}
 	return $user;
 }
 
+# must be called with a valid user!
+
+function common_forgetme() {
+	common_set_cookie(REMEMBERME, '', 0);
+}
+
+# who is the current user?
+function common_current_user() {
+
+	if (common_have_session()) {
+		$id = $_SESSION['userid'];
+		if ($id) {
+			# note: this should cache
+			$user = User::staticGet($id);
+			return $user;
+		}
+	}
+
+	# that didn't work; try to remember
+	$user = common_remembered_user();
+	return $user;
+}
+
+# Logins that are 'remembered' aren't 'real' -- they're subject to
+# cookie-stealing. So, we don't let them do certain things. New reg,
+# OpenID, and password logins _are_ real.
+
+function common_real_login($real=true) {
+	common_ensure_session();
+	$_SESSION['real_login'] = $real;
+}
+
+function common_is_real_login() {
+	return common_logged_in() && $_SESSION['real_login'];
+}
+
 # get canonical version of nickname for comparison
 function common_canonical_nickname($nickname) {
 	# XXX: UTF-8 canonicalization (like combining chars)