add onBadCertificate callback passthrough

CHANGELOG.md

@@ -1,3 +1,7 @@
+## 2.1.0
+
+- Add `onBadCertificate` to `SOCKSSocket.create()` and `SocksConnection.start()`, passed through to `RawSecureSocket.secure`. `allowBadCertificates: true` still accepts everything.
+
 ## 2.0.0
 
 - **Breaking:** Remove `SOCKSSocket.socket` so transport operations cannot bypass the wrapper's write queue and lifecycle tracking. Use `destroy()`, `closeOutput()`, `close()`, `write()`, `outputStream`, and `inputStream` instead. `closeOutput()` preserves the native socket's write-side half-close behavior.

lib/socks_connection.dart

@@ -38,6 +38,7 @@ class SocksConnection {
     required int targetPort,
     String? tlsHost,
     SecurityContext? securityContext,
+    bool Function(X509Certificate)? onBadCertificate,
     SocksCredentials? credentials,
     List<String>? supportedProtocols,
     Duration timeout = const Duration(seconds: 30),
@@ -55,7 +56,7 @@ class SocksConnection {
     final request = encodeSocksDestination(targetHost, targetPort);
     final operation = _ConnectOperation();
     operation.run(proxyHost, proxyPort, request, tlsHost, securityContext,
-        credentials, supportedProtocols, timeout);
+        onBadCertificate, credentials, supportedProtocols, timeout);
     return ConnectionTask.fromSocket(operation.result.future, operation.cancel);
   }
 }
@@ -90,6 +91,7 @@ class _ConnectOperation {
       List<int> request,
       String? tlsHost,
       SecurityContext? context,
+      bool Function(X509Certificate)? onBadCertificate,
       SocksCredentials? credentials,
       List<String>? supportedProtocols,
       Duration timeout) async {
@@ -127,6 +129,7 @@ class _ConnectOperation {
             subscription: channel.detach(),
             host: tlsHost,
             context: context,
+            onBadCertificate: onBadCertificate,
             supportedProtocols: supportedProtocols);
         _raw = secured;
         if (_aborted) {

lib/socks_socket.dart

@@ -146,6 +146,9 @@ class SOCKSSocket {
 
   final SecurityContext? _securityContext;
 
+  /// Passed to [RawSecureSocket.secure]; ignored with [allowBadCertificates].
+  final bool Function(X509Certificate)? _onBadCertificate;
+
   final bool? _requireIsolation;
 
   final bool _closeOnPeerEof;
@@ -199,6 +202,7 @@ class SOCKSSocket {
       this._operationTimeout,
       this._allowBadCertificates,
       this._securityContext,
+      this._onBadCertificate,
       this._requireIsolation,
       this._closeOnPeerEof);
 
@@ -216,6 +220,7 @@ class SOCKSSocket {
     Duration operationTimeout = const Duration(seconds: 30),
     bool allowBadCertificates = false,
     SecurityContext? securityContext,
+    bool Function(X509Certificate)? onBadCertificate,
     bool? requireIsolation,
     bool closeOnPeerEof = true,
   }) async {
@@ -245,6 +250,7 @@ class SOCKSSocket {
         operationTimeout,
         allowBadCertificates,
         securityContext,
+        onBadCertificate,
         requireIsolation,
         closeOnPeerEof);
     await instance._init();
@@ -408,7 +414,8 @@ class SOCKSSocket {
           subscription: channel.detach(),
           host: domain,
           context: _securityContext,
-          onBadCertificate: _allowBadCertificates ? (_) => true : null,
+          onBadCertificate:
+              _allowBadCertificates ? (_) => true : _onBadCertificate,
         );
         try {
           _channel = RawChannel(await _handshake(() => upgrade));

pubspec.yaml

@@ -1,6 +1,6 @@
 name: socks_socket
 description: SOCKS version 5 sockets for Dart and Flutter, *eg.* ElectrumX and/or Fulcrum over Tor via socket(s).
-version: 2.0.0
+version: 2.1.0
 repository: https://github.com/cypherstack/socks_socket
 
 environment:

test/socks_connection_test.dart

@@ -10,6 +10,7 @@ ConnectionTask<Socket> connect(TunnelProxy proxy,
         {String host = 'unresolvable.invalid',
         String? tlsHost,
         SecurityContext? context,
+        bool Function(X509Certificate)? onBadCertificate,
         SocksCredentials? credentials,
         List<String>? supportedProtocols,
         Duration timeout = const Duration(seconds: 3)}) =>
@@ -20,6 +21,7 @@ ConnectionTask<Socket> connect(TunnelProxy proxy,
         targetPort: 443,
         tlsHost: tlsHost,
         securityContext: context,
+        onBadCertificate: onBadCertificate,
         credentials: credentials,
         supportedProtocols: supportedProtocols,
         timeout: timeout);
@@ -252,6 +254,31 @@ void main() {
       await proxy.disconnected.future.timeout(const Duration(seconds: 2));
     });
   }
+  test('onBadCertificate can accept an untrusted certificate', () async {
+    final server = await SecureServerSocket.bind(
+        InternetAddress.loopbackIPv4, 0, certificates.serverContext());
+    final accepted = <Socket>[];
+    server.listen(accepted.add, onError: (Object _) {});
+    addTearDown(() async {
+      for (final socket in accepted) {
+        socket.destroy();
+      }
+      await server.close();
+    });
+    final proxy = TunnelProxy(upstreamPort: server.port);
+    await proxy.start();
+    addTearDown(proxy.close);
+    X509Certificate? offered;
+    final socket = await connect(proxy,
+        tlsHost: 'localhost', context: SecurityContext(withTrustedRoots: false),
+        onBadCertificate: (certificate) {
+      offered = certificate;
+      return true;
+    }).socket;
+    addTearDown(socket.destroy);
+    expect(socket, isA<SecureSocket>());
+    expect(offered, isNotNull);
+  });
   test('renegotiate is unsupported on the TLS socket', () async {
     final server = await SecureServerSocket.bind(
         InternetAddress.loopbackIPv4, 0, certificates.serverContext());

test/tls_configuration_test.dart

@@ -28,4 +28,29 @@ void main() {
     await socket.write('custom TLS');
     expect(utf8.decode(await reply), 'custom TLS');
   });
+
+  test('SOCKSSocket passes onBadCertificate to the TLS upgrade', () async {
+    final certificates = TestCertificates.generate();
+    final proxy = MockSocksServer()
+      ..sslEnabled = true
+      ..securityContext = certificates.serverContext();
+    await proxy.start();
+    addTearDown(proxy.stop);
+    X509Certificate? offered;
+    final socket = await SOCKSSocket.create(
+      proxyHost: InternetAddress.loopbackIPv4.address,
+      proxyPort: proxy.port,
+      sslEnabled: true,
+      securityContext: SecurityContext(withTrustedRoots: false),
+      onBadCertificate: (certificate) {
+        offered = certificate;
+        return true;
+      },
+    );
+    addTearDown(socket.close);
+    await socket.connect();
+    await socket.connectTo('localhost', 443);
+    expect(socket.state, ConnectionState.connected);
+    expect(offered, isNotNull);
+  });
 }