x509 delayed authentication

Author: Giorgio Franceschetti

lib/src/database/db.dart

@@ -730,15 +730,33 @@ class Db {
         .toList();
   }
 
+  /// Method for authentication with X509 certificate.
+  /// In the conection parameters you have not to set
+  /// X509 if you want to use this delayed auth function.
+  Future<bool> authenticateX509({Connection? connection}) async =>
+      authenticate(null, null,
+          connection: connection,
+          authScheme: AuthenticationScheme.X509,
+          authDb: r'$external');
+
   Future<bool> authenticate(String? userName, String? password,
-      {Connection? connection}) async {
+      {Connection? connection,
+      AuthenticationScheme? authScheme,
+      String? authDb}) async {
     var credential = UsernamePasswordCredential()
       ..username = userName
       ..password = password;
 
     (connection ?? masterConnection).serverConfig.userName ??= userName;
     (connection ?? masterConnection).serverConfig.password ??= password;
 
+    if (authScheme != null) {
+      _authenticationScheme = authScheme;
+    }
+    if (authDb != null) {
+      authSourceDb = Db._authDb(authDb);
+    }
+
     if (_authenticationScheme == null) {
       throw MongoDartError('Authentication scheme not specified');
     }

test/auth_tests/client_x_509_test.dart

@@ -5,6 +5,8 @@ import 'dart:io';
 import 'package:test/test.dart';
 import 'package:mongo_dart/mongo_dart.dart';
 
+import '../utils/throw_utils.dart';
+
 // Run server1 with these parameters:
 // mongod --port 27038  --dbpath <your-data-path> --oplogSize 128
 //  --tlsMode requireTLS --tlsCertificateKeyFile
@@ -15,6 +17,7 @@ import 'package:mongo_dart/mongo_dart.dart';
 const dbName = 'mongodb-auth';
 const defaultUri =
     'mongodb://127.0.0.1:27038/$dbName?authMechanism=MONGODB-X509';
+const lateAuthUri = 'mongodb://127.0.0.1:27038/$dbName';
 
 void main() async {
   bool serverfound = false;
@@ -194,13 +197,16 @@ void main() async {
       await db.close();
     });
     test('Connect & Authenticate - Simple find()', () async {
-      var db = Db(defaultUri);
+      var db = Db(lateAuthUri);
 
       await db.open(
           secure: true,
           tlsCAFile: caCertFile.path,
           tlsCertificateKeyFile: pemFile.path);
-      await db.collection('test').find().toList();
+      var collection = db.collection('test');
+      expect(() => collection.find().toList(), throwsMongoDartError);
+      await db.authenticateX509();
+      await collection.find().toList();
       expect(db.masterConnection.isAuthenticated, isTrue);
       await db.close();
     });