platform/lib/src/strategies/local.dart
2019-01-05 18:54:48 -05:00

97 lines
3.2 KiB
Dart

import 'dart:async';
import 'dart:convert';
import 'package:angel_framework/angel_framework.dart';
import '../options.dart';
import '../strategy.dart';
bool _validateString(String str) => str != null && str.isNotEmpty;
/// Determines the validity of an incoming username and password.
typedef FutureOr<User> LocalAuthVerifier<User>(
String username, String password);
class LocalAuthStrategy<User> extends AuthStrategy<User> {
RegExp _rgxBasic = new RegExp(r'^Basic (.+)$', caseSensitive: false);
RegExp _rgxUsrPass = new RegExp(r'^([^:]+):(.+)$');
LocalAuthVerifier<User> verifier;
String usernameField;
String passwordField;
String invalidMessage;
final bool allowBasic;
final bool forceBasic;
String realm;
LocalAuthStrategy(this.verifier,
{String this.usernameField = 'username',
String this.passwordField = 'password',
String this.invalidMessage =
'Please provide a valid username and password.',
bool this.allowBasic = true,
bool this.forceBasic = false,
String this.realm = 'Authentication is required.'}) {}
@override
Future<User> authenticate(RequestContext req, ResponseContext res,
[AngelAuthOptions options_]) async {
AngelAuthOptions options = options_ ?? new AngelAuthOptions();
User verificationResult;
if (allowBasic) {
String authHeader = req.headers.value('authorization') ?? "";
if (_rgxBasic.hasMatch(authHeader)) {
String base64AuthString = _rgxBasic.firstMatch(authHeader).group(1);
String authString =
new String.fromCharCodes(base64.decode(base64AuthString));
if (_rgxUsrPass.hasMatch(authString)) {
Match usrPassMatch = _rgxUsrPass.firstMatch(authString);
verificationResult =
await verifier(usrPassMatch.group(1), usrPassMatch.group(2));
} else
throw new AngelHttpException.badRequest(errors: [invalidMessage]);
if (verificationResult == false || verificationResult == null) {
res
..statusCode = 401
..headers['www-authenticate'] = 'Basic realm="$realm"';
await res.close();
return null;
}
return verificationResult;
}
}
if (verificationResult == null) {
var body = await req
.parseBody()
.then((_) => req.bodyAsMap)
.catchError((_) => <String, dynamic>{});
if (_validateString(body[usernameField]?.toString()) &&
_validateString(body[passwordField]?.toString())) {
verificationResult = await verifier(
body[usernameField]?.toString(), body[passwordField]?.toString());
}
}
if (verificationResult == false || verificationResult == null) {
if (options.failureRedirect != null &&
options.failureRedirect.isNotEmpty) {
res.redirect(options.failureRedirect, code: 401);
return null;
}
if (forceBasic) {
res.headers['www-authenticate'] = 'Basic realm="$realm"';
throw new AngelHttpException.notAuthenticated();
}
return null;
} else if (verificationResult != null && verificationResult != false) {
return verificationResult;
} else {
throw new AngelHttpException.notAuthenticated();
}
}
}