+1

README.md

@@ -1,10 +1,11 @@
 # security
-[![version 0.0.0](https://img.shields.io/badge/pub-v0.0.0--alpha-red.svg)](https://pub.dartlang.org/packages/angel_security)
+[![version 0.0.0-alpha+1](https://img.shields.io/badge/pub-v0.0.0--alpha+1-red.svg)](https://pub.dartlang.org/packages/angel_security)
 [![build status](https://travis-ci.org/angel-dart/security.svg)](https://travis-ci.org/angel-dart/security)
 
-Angel middleware designed to enhance application security.
+Angel middleware designed to enhance application security by patching common Web security
+holes.
 
-Currently far from finished, with incomplete code coverage - **USE AT YOUR OWN RISK!!!**
+Currently unfinished, with incomplete code coverage - **USE AT YOUR OWN RISK!!!**
 
 ## Sanitizing HTML
 
@@ -13,4 +14,24 @@ app.before.add(sanitizeHtmlInput());
 
 // Or:
 app.chain(sanitizeHtmlInput()).get(...)
+```
+
+## CSRF Tokens
+
+```dart
+app.chain(verifyCsrfToken()).post('/form', ...);
+app.responseFinalizers.add(setCsrfToken());
+```
+
+## Banning IP's
+
+```dart
+app.before.add(banIp('1.2.3.4'));
+
+// Or a range:
+app.before.add(banIp('1.2.3.*'));
+app.before.add(banIp('1.2.*.4'));
+
+// Or multiple filters:
+app.before.add(banIp(['1.2.3.4', '192.*.*.*', new RegExp(r'1\.2.\3.\4')]));
 ```

lib/angel_security.dart

@@ -1,4 +1,6 @@
 /// Angel middleware designed to enhance application security.
 library angel_security;
 
-export 'src/sanitize.dart';
+export 'src/ban.dart';
+export 'src/csrf.dart';
+export 'src/sanitize.dart';

lib/src/ban.dart

@@ -0,0 +1,50 @@
+import 'dart:io';
+import 'package:angel_framework/angel_framework.dart';
+
+/// Throws a 403 Forbidden if the user's IP is banned.
+///
+/// [filter] can be:
+/// A `String`, `RegExp`, `InternetAddress`, or an `Iterable`.
+///
+/// String can take the following formats:
+/// 1. 1.2.3.4
+/// 2. 1.2.3.*, 1.2.*.*, etc.
+RequestMiddleware banIp(filter,
+    {String message:
+        'Your IP address is forbidden from accessing this server.'}) {
+  var filters = [];
+  Iterable inputs = filter is Iterable ? filter : [filter];
+
+  for (var input in inputs) {
+    if (input is RegExp || input is InternetAddress)
+      filters.add(input);
+    else if (input is String) {
+      if (!input.contains('*'))
+        filters.add(input);
+      else {
+        filters.add(new RegExp(input.replaceAll('*', '[0-9]+')));
+      }
+    } else
+      throw new ArgumentError('Cannot use $input as an IP filter.');
+  }
+
+  return (RequestContext req, ResponseContext res) async {
+    var ip = req.ip;
+
+    bool check() {
+      for (var input in filters) {
+        if (input is RegExp && input.hasMatch(ip))
+          return false;
+        else if (input is InternetAddress && input.address == ip)
+          return false;
+        else if (input is String && input == ip) return false;
+      }
+
+      return true;
+    }
+
+    if (!check()) throw new AngelHttpException.forbidden(message: message);
+
+    return true;
+  };
+}

lib/src/csrf.dart

@@ -0,0 +1,44 @@
+import 'dart:io';
+import 'package:angel_framework/angel_framework.dart';
+import 'package:uuid/uuid.dart';
+
+final Uuid _uuid = new Uuid();
+
+/// Ensures that the request contains a correct CSRF token.
+RequestMiddleware verifyCsrfToken(
+    {bool allowCookie: false,
+    bool allowQuery: true,
+    String name: 'csrf_token'}) {
+  return (RequestContext req, res) async {
+    String csrfToken;
+
+    if (allowQuery && req.query.containsKey(name))
+      csrfToken = req.query[name];
+    else if (req.body.containsKey(name))
+      csrfToken = req.body[name];
+    else if (allowCookie) {
+      var cookie =
+          req.cookies.firstWhere((c) => c.name == name, orElse: () => null);
+      if (cookie != null) csrfToken = cookie.value;
+    }
+
+    if (csrfToken == null || !req.session.containsKey(name))
+      throw new AngelHttpException.badRequest(message: 'Missing CSRF token.');
+
+    String correctToken = req.session[name];
+
+    if (csrfToken != correctToken)
+      throw new AngelHttpException.badRequest(message: 'Invalid CSRF token.');
+
+    return true;
+  };
+}
+
+/// Adds a CSRF token to the session, if none is present.
+RequestHandler setCsrfToken({String name: 'csrf_token', bool cookie: false}) {
+  return (RequestContext req, res) async {
+    if (!req.session.containsKey(name)) req.session[name] = _uuid.v4();
+    if (cookie) res.cookies.add(new Cookie(name, req.session[name]));
+    return true;
+  };
+}

pubspec.yaml

@@ -1,6 +1,6 @@
 name: angel_security
-version: 0.0.0-alpha
-description: Angel middleware designed to enhance application security.
+version: 0.0.0-alpha+1
+description: Angel middleware designed to enhance application security by patching common Web security holes.
 author: Tobe O <thosakwe@gmail.com>
 environment:
   sdk: ">=1.19.0"

test/ban.dart

@@ -0,0 +1,24 @@
+import 'package:angel_framework/angel_framework.dart';
+import 'package:angel_security/angel_security.dart';
+import 'package:angel_test/angel_test.dart';
+import 'package:test/test.dart';
+
+main() {
+  Angel app;
+  TestClient client;
+
+  setUp(() async {
+    app = new Angel()..chain(banIp('*.*.*.*')).get('/ban', 'WTF');
+
+    client = await connectTo(app);
+  });
+
+  tearDown(() => client.close());
+
+  test('ban everyone', () async {
+    var response = await client.get('/ban');
+    print(response.body);
+    expect(response, hasStatus(403));
+    expect(response.body.contains('WTF'), isFalse);
+  });
+}

test/csrf_token.dart

@@ -0,0 +1,50 @@
+import 'package:angel_framework/angel_framework.dart';
+import 'package:angel_security/angel_security.dart';
+import 'package:angel_test/angel_test.dart';
+import 'package:http/http.dart' as http;
+import 'package:test/test.dart';
+
+final RegExp _sessId = new RegExp(r'DARTSESSID=([^;]+);');
+
+main() async {
+  Angel app;
+  TestClient client;
+
+  setUp(() async {
+    app = new Angel()..responseFinalizers.add(setCsrfToken());
+
+    app.chain(verifyCsrfToken()).get('/valid', 'Valid!');
+
+    client = await connectTo(app);
+  });
+
+  tearDown(() => client.close());
+
+  test('need pre-existing token', () async {
+    var response = await client.get('/valid?csrf_token=evil');
+    print(response.body);
+    expect(response, hasStatus(400));
+    expect(response.body, contains('Missing'));
+  });
+
+  test('fake token', () async {
+    // Get a valid CSRF, but ignore it.
+    var response = await client.get('/');
+    var sessionId = getCookie(response);
+    response = await client.get('/valid?csrf_token=evil',
+        headers: {'cookie': 'DARTSESSID=$sessionId'});
+    print(response.body);
+    expect(response, hasStatus(400));
+    expect(response.body.contains('Valid'), isFalse);
+    expect(response.body, contains('Invalid CSRF token'));
+  });
+}
+
+String getCookie(http.Response response) {
+  if (response.headers.containsKey('set-cookie')) {
+    var header = response.headers['set-cookie'];
+    var match = _sessId.firstMatch(header);
+    return match?.group(1);
+  } else
+    return null;
+}