Add socks support on BTCPay Server to query onion endpoints

BTCPayServer/Services/SocketFactory.cs

@@ -0,0 +1,76 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Net;
+using System.Net.Sockets;
+using System.Text;
+using System.Threading;
+using System.Threading.Tasks;
+using BTCPayServer.Configuration;
+using BTCPayServer.Tor;
+
+namespace BTCPayServer.Services
+{
+    public class SocketFactory
+    {
+        private readonly BTCPayServerOptions _options;
+        public SocketFactory(BTCPayServerOptions options)
+        {
+            _options = options;
+        }
+        public async Task<Socket> ConnectAsync(EndPoint endPoint, SocketType socketType, ProtocolType protocolType, CancellationToken cancellationToken)
+        {
+            Socket socket = null;
+            try
+            {
+                if (endPoint is IPEndPoint ipEndpoint)
+                {
+                    socket = new Socket(ipEndpoint.Address.AddressFamily, SocketType.Stream, ProtocolType.Tcp);
+                    await socket.ConnectAsync(ipEndpoint).WithCancellation(cancellationToken);
+                }
+                else if (endPoint is OnionEndpoint onionEndpoint)
+                {
+                    if (_options.SocksEndpoint == null)
+                        throw new NotSupportedException("It is impossible to connect to an onion address without btcpay's -socksendpoint configured");
+                    socket = await Socks5Connect.ConnectSocksAsync(_options.SocksEndpoint, onionEndpoint, cancellationToken);
+                }
+                else if (endPoint is DnsEndPoint dnsEndPoint)
+                {
+                    var address = (await Dns.GetHostAddressesAsync(dnsEndPoint.Host)).FirstOrDefault();
+                    socket = new Socket(address.AddressFamily, SocketType.Stream, ProtocolType.Tcp);
+                    await socket.ConnectAsync(dnsEndPoint).WithCancellation(cancellationToken);
+                }
+                else
+                    throw new NotSupportedException("Endpoint type not supported");
+            }
+            catch
+            {
+                CloseSocket(ref socket);
+                throw;
+            }
+            return socket;
+        }
+
+        private void CloseSocket(ref Socket s)
+        {
+            if (s == null)
+                return;
+            try
+            {
+                s.Shutdown(SocketShutdown.Both);
+            }
+            catch
+            {
+                try
+                {
+                    s.Dispose();
+                }
+                catch { }
+            }
+            finally
+            {
+                s = null;
+            }
+        }
+    }
+}