:)

.analysis-options

@@ -0,0 +1,3 @@
+analyzer:
+  exclude:
+  - .scripts-bin/**/*.dart

.gitignore

@@ -5,6 +5,7 @@
 .packages
 .project
 .pub/
+.scripts-bin/
 build/
 **/packages/
 
@@ -25,3 +26,5 @@ doc/api/
 # Don't commit pubspec lock file 
 # (Library packages only! Remove pattern if developing an application package)
 pubspec.lock
+
+log.txt

.vscode/launch.json

@@ -0,0 +1,14 @@
+{
+    "version": "0.2.0",
+    "configurations": [
+        {
+            "name": "Example server",
+            "type": "dart-cli",
+            "request": "launch",
+            "cwd": "${workspaceRoot}/example",
+            "debugSettings": "${command.debugSettings}",
+            "program": "${workspaceRoot}/example/server.dart",
+            "args": []
+        }
+    ]
+}

README.md

@@ -1,2 +1,4 @@
 # auth_twitter
 angel_auth strategy for Twitter login.
+
+See the [example](example/server.dart);

example/server.dart

@@ -0,0 +1,44 @@
+import 'dart:io';
+import 'package:angel_auth/angel_auth.dart';
+import 'package:angel_auth_twitter/angel_auth_twitter.dart';
+import 'package:angel_diagnostics/angel_diagnostics.dart';
+import 'package:angel_framework/angel_framework.dart';
+
+const Map<String, String> TWITTER_CONFIG = const {
+  'callback': 'http://localhost:3000/auth/twitter/callback',
+  'key': 'qlrBWXneoSYZKS2bT4TGHaNaV',
+  'secret': 'n2oA0ZtR7TzYincpMYElRpyYovAQlhYizTkTm2x5QxjH6mLVyE'
+};
+
+main() async {
+  var app = new Angel();
+
+  var auth = new AngelAuth(jwtKey: 'AUTH_TWITTER_SECRET', allowCookie: false);
+  await app.configure(auth);
+
+  auth.serializer = (user) async => user.id_str;
+
+  auth.deserializer = (id) async {
+    // Of course, in a real app, you would fetch
+    // user data, but not here.
+    return {'id': id};
+  };
+
+  auth.strategies.add(new TwitterStrategy(config: TWITTER_CONFIG));
+
+  app
+    ..get('/', auth.authenticate('twitter'))
+    ..get(
+        '/auth/twitter/callback',
+        auth.authenticate('twitter',
+            new AngelAuthOptions(callback: (req, res, jwt) {
+          return res.redirect('/home?token=$jwt');
+        })))
+    ..chain('auth').get('/home', (req, res) {
+      res
+        ..write('Hello, user #${req.user["id"]}!')
+        ..end();
+    });
+
+  await new DiagnosticsServer(app, new File('log.txt')).startServer(null, 3000);
+}

lib/angel_auth_twitter.dart

@@ -0,0 +1,157 @@
+import 'dart:async';
+import 'dart:collection';
+import 'dart:convert';
+import 'dart:io';
+import 'package:angel_auth/angel_auth.dart';
+import 'package:angel_framework/angel_framework.dart';
+import 'package:crypto/crypto.dart';
+import 'package:random_string/random_string.dart' as rs;
+
+const String _ENDPOINT = "https://api.twitter.com";
+
+class TwitterStrategy extends AuthStrategy {
+  HttpClient _client = new HttpClient();
+  final Map<String, dynamic> config;
+
+  @override
+  String get name => 'twitter';
+
+  TwitterStrategy({this.config: const {}});
+
+  String _createSignature(
+      String method, String uriString, Map<String, String> params,
+      {String tokenSecret: ""}) {
+    // Not only do we need to sort the parameters, but we need to URI-encode them as well.
+    var encoded = new SplayTreeMap();
+    for (String key in params.keys) {
+      encoded[Uri.encodeComponent(key)] = Uri.encodeComponent(params[key]);
+    }
+
+    String collectedParams =
+        encoded.keys.map((key) => "$key=${encoded[key]}").join("&");
+
+    String baseString =
+        "$method&${Uri.encodeComponent(uriString)}&${Uri.encodeComponent(
+        collectedParams)}";
+
+    String signingKey = "${Uri.encodeComponent(
+        config['secret'])}&$tokenSecret";
+
+    // After you create a base string and signing key, we need to hash this via HMAC-SHA1
+    var hmac = new Hmac(sha1, signingKey.codeUnits);
+
+    // The returned signature should be the resulting hash, Base64-encoded
+    return BASE64.encode(hmac.convert(baseString.codeUnits).bytes);
+  }
+
+  Future<HttpClientRequest> _prepRequest(String path,
+      {String method: "GET",
+      Map data: const {},
+      String accessToken,
+      String tokenSecret: ""}) async {
+    Map headers = new Map.from(data);
+    headers["oauth_version"] = "1.0";
+    headers["oauth_consumer_key"] = config['key'];
+
+    // The implementation of _randomString doesn't matter - just generate a 32-char
+    // alphanumeric string.
+    headers["oauth_nonce"] = rs.randomAlphaNumeric(32);
+    headers["oauth_signature_method"] = "HMAC-SHA1";
+    headers["oauth_timestamp"] =
+        (new DateTime.now().millisecondsSinceEpoch / 1000).round().toString();
+
+    if (accessToken != null) {
+      headers["oauth_token"] = accessToken;
+    }
+
+    var request = await _client.openUrl(method, Uri.parse("$_ENDPOINT$path"));
+
+    headers['oauth_signature'] = _createSignature(method,
+        request.uri.toString().replaceAll("?${request.uri.query}", ""), headers,
+        tokenSecret: tokenSecret);
+
+    var oauthString = headers.keys
+        .map((name) => '$name="${Uri.encodeComponent(headers[name])}"')
+        .join(", ");
+
+    return request
+      ..headers.set(HttpHeaders.AUTHORIZATION, "OAuth $oauthString");
+  }
+
+  _mapifyRequest(HttpClientRequest request) async {
+    var rs = await request.close();
+    var body = await rs.transform(UTF8.decoder).join();
+
+    if (rs.statusCode != HttpStatus.OK) {
+      throw new AngelHttpException.NotAuthenticated(
+          message: 'Twitter authentication error: $body');
+    }
+
+    var pairs = body.split('&');
+    var data = {};
+
+    for (var pair in pairs) {
+      var index = pair.indexOf('=');
+
+      if (index > -1) {
+        var key = pair.substring(0, index);
+        var value = Uri.decodeFull(pair.substring(index + 1));
+        data[key] = value;
+      }
+    }
+
+    return data;
+  }
+
+  Future<Map<String, String>> createAccessToken(
+      String token, String verifier) async {
+    var request = await _prepRequest("/oauth/access_token",
+        method: "POST", data: {"verifier": verifier}, accessToken: token);
+
+    request.headers.contentType =
+        ContentType.parse("application/x-www-form-urlencoded");
+    request.writeln("oauth_verifier=$verifier");
+
+    return _mapifyRequest(request);
+  }
+
+  Future<Map<String, String>> createRequestToken() async {
+    var request = await _prepRequest("/oauth/request_token",
+        method: "POST", data: {"oauth_callback": config['callback']});
+
+    // _mapifyRequest is a function that sends a request and parses its URL-encoded
+    // response into a Map. This detail is not important.
+    return await _mapifyRequest(request);
+  }
+
+  @override
+  Future<bool> canLogout(RequestContext req, ResponseContext res) async => true;
+  @override
+  authenticate(RequestContext req, ResponseContext res,
+      [AngelAuthOptions options]) async {
+    if (options != null) {
+      return await authenticateCallback(req, res, options);
+    } else {
+      var result = await createRequestToken();
+      String token = result['oauth_token'];
+      res.redirect("$_ENDPOINT/oauth/authenticate?oauth_token=$token");
+      return false;
+    }
+  }
+
+  Future authenticateCallback(
+      RequestContext req, ResponseContext res, AngelAuthOptions options) async {
+    var token = req.query['oauth_token'];
+    var verifier = req.query['oauth_verifier'];
+    var loginData = await createAccessToken(token, verifier);
+
+    var oauthToken = loginData['oauth_token'];
+    var oauthTokenSecret = loginData['oauth_token_secret'];
+
+    var request = await _prepRequest('/1.1/account/verify_credentials.json',
+        accessToken: oauthToken, tokenSecret: oauthTokenSecret);
+    var rs = await request.close();
+    var body = await rs.transform(UTF8.decoder).join();
+    return new Extensible()..properties.addAll(JSON.decode(body));
+  }
+}

pubspec.yaml

@@ -0,0 +1,12 @@
+author: "Tobe O <thosakwe@gmail.com>"
+description: "angel_auth strategy for Twitter login."
+environment:
+  sdk: ">=1.19.0"
+homepage: "https://github.com/angel-dart/auth_twitter.git"
+name: "angel_auth_twitter"
+version: "1.0.0"
+dependencies: 
+  angel_auth: "^1.0.0-dev"
+  random_string: "^0.0.1"
+dev_dependencies: 
+  angel_diagnostics: "^1.0.0-dev+5"