Merge pull request #152 from clems4ever/cookie-theft

Prevention agains cookie theft

README.md

@@ -24,11 +24,12 @@ used in production to secure internal services in a small docker swarm cluster.
     5. [Access control](#access-control)
     6. [Basic authentication](#basic-authentication)
     7. [Session management with Redis](#session-management-with-redis)
-4. [Documentation](#documentation)
+4. [Security](#security)
+5. [Documentation](#documentation)
     1. [Authelia configuration](#authelia-configuration)
-    1. [API documentation](#api-documentation)
-5. [Contributing to Authelia](#contributing-to-authelia)
-6. [License](#license)
+    2. [API documentation](#api-documentation)
+6. [Contributing to Authelia](#contributing-to-authelia)
+7. [License](#license)
 
 ---
 
@@ -197,6 +198,29 @@ Please see [config.template.yml] to see an example of configuration.
 ### Session management with Redis
 When your users authenticate against Authelia, sessions are stored in a Redis key/value store. You can specify your own Redis instance in [config.template.yml].
 
+## Security
+
+### Protection against cookie theft
+
+Authelia uses two mechanism to protect against cookie theft:
+1. session attribute `httpOnly` set to true make client-side code unable to
+read the cookie.
+2. session attribute `secure` ensure the cookie will never be sent over an
+unsecure HTTP connections.
+
+### Protection against multi-domain cookie attacks
+
+Since Authelia uses multi-domain cookies to perform single sign-on, an
+attacker who poisonned a user's DNS cache can easily retrieve the user's
+cookies by making the user send a request to one of the attacker's IPs.
+
+To mitigate this risk, it's advisable to only use HTTPS connections with valid
+certificates and enforce it with HTTP Strict Transport Security ([HSTS]) so
+that the attacker must also require the certificate to retrieve the cookies.
+
+Note that using [HSTS] has consequences. That's why you should read the blog
+post nginx has written on [HSTS].
+
 ## Documentation
 ### Authelia configuration
 The configuration of the server is defined in the file 
@@ -246,4 +270,4 @@ Follow [contributing](CONTRIBUTORS.md) file.
 [auth_request]: http://nginx.org/en/docs/http/ngx_http_auth_request_module.html
 [Google Authenticator]: https://play.google.com/store/apps/details?id=com.google.android.apps.authenticator2&hl=en
 [config.template.yml]: https://github.com/clems4ever/authelia/blob/master/config.template.yml
-
+[HSTS]: https://www.nginx.com/blog/http-strict-transport-security-hsts-and-nginx/

docker-compose.yml

@@ -5,6 +5,8 @@ services:
     restart: always
     volumes:
       - ./config.template.yml:/etc/authelia/config.yml:ro
+    environment:
+      - NODE_TLS_REJECT_UNAUTHORIZED=0
     depends_on: 
       - redis
     networks:

example/authelia/docker-compose.yml

@@ -6,6 +6,8 @@ services:
     volumes:
       - ./config.template.yml:/etc/authelia/config.yml:ro
       - ./notifications:/var/lib/authelia/notifications
+    environment:
+      - NODE_TLS_REJECT_UNAUTHORIZED=0
     depends_on: 
       - redis
     networks:

example/nginx/nginx.conf

@@ -30,11 +30,14 @@ http {
         ssl_certificate     /etc/ssl/server.crt;
         ssl_certificate_key /etc/ssl/server.key;
 
+        add_header Strict-Transport-Security "max-age=31536000; includeSubDomains" always;
+        add_header X-Frame-Options "SAMEORIGIN";
 
         location / {
             proxy_set_header  X-Original-URI $request_uri;
             proxy_set_header  Host $http_host;
             proxy_set_header  X-Real-IP $remote_addr;
+            proxy_set_header  X-Forwarded-Proto $scheme;
 
             proxy_pass        http://authelia/;
 
@@ -57,6 +60,9 @@ http {
         ssl on;
         ssl_certificate     /etc/ssl/server.crt;
         ssl_certificate_key /etc/ssl/server.key;
+
+        add_header Strict-Transport-Security "max-age=31536000; includeSubDomains" always;
+        add_header X-Frame-Options "SAMEORIGIN";
     }
 
     server {
@@ -69,10 +75,14 @@ http {
         ssl_certificate     /etc/ssl/server.crt;
         ssl_certificate_key /etc/ssl/server.key;
 
+        add_header Strict-Transport-Security "max-age=31536000; includeSubDomains" always;
+        add_header X-Frame-Options "SAMEORIGIN";
+
         location /auth_verify {
             internal;
             proxy_set_header  X-Original-URI $request_uri;
             proxy_set_header  X-Real-IP $remote_addr;
+            proxy_set_header  X-Forwarded-Proto $scheme;
             proxy_set_header  Host $http_host;
             proxy_set_header  Content-Length "";
 
@@ -122,10 +132,14 @@ http {
         ssl_certificate     /etc/ssl/server.crt;
         ssl_certificate_key /etc/ssl/server.key;
 
+        add_header Strict-Transport-Security "max-age=31536000; includeSubDomains" always;
+        add_header X-Frame-Options "SAMEORIGIN";
+
         location /auth_verify {
             internal;
             proxy_set_header  X-Original-URI $request_uri;
             proxy_set_header  X-Real-IP $remote_addr;
+            proxy_set_header  X-Forwarded-Proto $scheme;
             proxy_set_header  Host $http_host;
             proxy_set_header  Content-Length "";
 
@@ -158,10 +172,14 @@ http {
         ssl_certificate     /etc/ssl/server.crt;
         ssl_certificate_key /etc/ssl/server.key;
 
+        add_header Strict-Transport-Security "max-age=31536000; includeSubDomains" always;
+        add_header X-Frame-Options "SAMEORIGIN";
+
         location /auth_verify {
             internal;
             proxy_set_header  X-Original-URI $request_uri;
             proxy_set_header  X-Real-IP $remote_addr;
+            proxy_set_header  X-Forwarded-Proto $scheme;
             proxy_set_header  Host $http_host;
             proxy_set_header  Content-Length "";
 
@@ -194,10 +212,14 @@ http {
         ssl_certificate     /etc/ssl/server.crt;
         ssl_certificate_key /etc/ssl/server.key;
 
+        add_header Strict-Transport-Security "max-age=31536000; includeSubDomains" always;
+        add_header X-Frame-Options "SAMEORIGIN";
+
         location /auth_verify {
             internal;
             proxy_set_header  X-Original-URI $request_uri;
             proxy_set_header  X-Real-IP $remote_addr;
+            proxy_set_header  X-Forwarded-Proto $scheme;
             proxy_set_header  Host $http_host;
             proxy_set_header  Content-Length "";
 
@@ -230,10 +252,14 @@ http {
         ssl_certificate     /etc/ssl/server.crt;
         ssl_certificate_key /etc/ssl/server.key;
 
+        add_header Strict-Transport-Security "max-age=31536000; includeSubDomains" always;
+        add_header X-Frame-Options "SAMEORIGIN";
+
         location /auth_verify {
             internal;
             proxy_set_header  X-Original-URI $request_uri;
             proxy_set_header  X-Real-IP $remote_addr;
+            proxy_set_header  X-Forwarded-Proto $scheme;
             proxy_set_header  Host $http_host;
             proxy_set_header  Content-Length "";
 

server/src/index.ts

@@ -1,7 +1,5 @@
 #! /usr/bin/env node
 
-process.env.NODE_TLS_REJECT_UNAUTHORIZED = "0";
-
 import Server from "./lib/Server";
 import { GlobalDependencies } from "../types/Dependencies";
 import YAML = require("yamljs");

server/src/lib/Server.ts

@@ -23,8 +23,8 @@ import * as http from "http";
 const addRequestId = require("express-request-id")();
 
 // Constants
-
 const TRUST_PROXY = "trust proxy";
+const X_POWERED_BY = "x-powered-by";
 const VIEWS = "views";
 const VIEW_ENGINE = "view engine";
 const PUG = "pug";
@@ -54,9 +54,9 @@ export default class Server {
     app.use(BodyParser.json());
     app.use(deps.session(expressSessionOptions));
     app.use(addRequestId);
-    app.disable("x-powered-by");
+    app.disable(X_POWERED_BY);
+    app.enable(TRUST_PROXY);
 
-    app.set(TRUST_PROXY, 1);
     app.set(VIEWS, viewsDirectory);
     app.set(VIEW_ENGINE, PUG);
 

server/src/lib/configuration/SessionConfigurationBuilder.ts

@@ -12,7 +12,8 @@ export class SessionConfigurationBuilder {
       resave: false,
       saveUninitialized: true,
       cookie: {
-        secure: false,
+        secure: true,
+        httpOnly: true,
         maxAge: configuration.session.expiration,
         domain: configuration.session.domain
       },

server/test/SessionConfigurationBuilder.test.ts

@@ -73,7 +73,8 @@ describe("test session configuration builder", function () {
       resave: false,
       saveUninitialized: true,
       cookie: {
-        secure: false,
+        secure: true,
+        httpOnly: true,
         maxAge: 3600,
         domain: "example.com"
       }
@@ -153,7 +154,8 @@ describe("test session configuration builder", function () {
       resave: false,
       saveUninitialized: true,
       cookie: {
-        secure: false,
+        secure: true,
+        httpOnly: true,
         maxAge: 3600,
         domain: "example.com"
       },