Meziantou.Framework.TdsServer 1.0.0

Meziantou.Framework.TdsServer

Meziantou.Framework.TdsServer is a callback-based server library for accepting TDS (SQL Server protocol) connections.

Features

• Accepts TDS client connections over TCP
• Callback for authentication (SQL login + token-based extension data)
• Callback for query handling (SQL batch and RPC requests)
• Serializes result sets and protocol tokens back to clients
• Native JSON column type serialization (TDSType.JSON, UTF-8 payload)
• ASP.NET Core hosting integration through IHostApplicationBuilder

Usage

using System.Net;
using Meziantou.Framework.Tds;
using Meziantou.Framework.Tds.Handler;
using Meziantou.Framework.Tds.Hosting;

var builder = WebApplication.CreateBuilder(args);
builder.AddTdsServer(options =>
{
    options.AddTcpListener(port: 14330, bindAddress: IPAddress.Loopback);
});

var app = builder.Build();
app.MapTdsHandlers(
    authenticate: async (context, cancellationToken) =>
    {
        if (context.UserName == "sa" && context.Password == "Password123!")
            return TdsAuthenticationResult.Success();

        return TdsAuthenticationResult.Fail("Login failed");
    },
    query: async (context, cancellationToken) =>
    {
        var resultSet = new TdsResultSet();
        resultSet.Columns.Add(new TdsColumn("Message", TdsColumnType.NVarChar));
        resultSet.Rows.Add(["Hello from TDS server"]);

        var result = new TdsQueryResult();
        result.ResultSets.Add(resultSet);
        return result;
    });

app.Run();

Access command text, stored procedure name, and parameters

The query callback gives you access to both SQL batch text and RPC/stored-procedure metadata:

app.MapTdsHandlers(
    authenticate: async (context, cancellationToken) => TdsAuthenticationResult.Success(),
    query: async (context, cancellationToken) =>
    {
        if (context.RequestType == TdsQueryRequestType.SqlBatch)
        {
            var commandText = context.CommandText; // e.g. "SELECT * FROM Users WHERE Id = @id"
        }
        else if (context.RequestType == TdsQueryRequestType.Rpc)
        {
            var procedureName = context.ProcedureName; // e.g. "sp_executesql" or your procedure name
        }

        foreach (var parameter in context.Parameters)
        {
            var parameterName = parameter.Name;
            var rawValue = parameter.Value.RawValue;
            var stringValue = parameter.Value.AsString();
            var intValue = parameter.Value.AsInt32();
            var json = parameter.Value.AsJson();
            var xml = parameter.Value.AsXml();
        }

        return new TdsQueryResult();
    });

TLS configuration

TLS uses SQL Server PRELOGIN encryption negotiation on the same TCP endpoint. Configure either a PFX file or a PEM certificate/private key pair. For Microsoft.Data.SqlClient interoperability, the server negotiates TLS 1.2 for encrypted TDS sessions.

PFX

builder.AddTdsServer(options =>
{
    options.AddTcpListener(port: 14330, bindAddress: IPAddress.Loopback);
    options.TlsPfxPath = "certificates/server.pfx";
    options.TlsPfxPassword = "Password123!";
});

PEM certificate + private key

builder.AddTdsServer(options =>
{
    options.AddTcpListener(port: 14330, bindAddress: IPAddress.Loopback);
    options.TlsPemCertificatePath = "certificates/server.crt.pem";
    options.TlsPemPrivateKeyPath = "certificates/server.key.pem";
});

Use client connection strings with Encrypt=True to require TLS, or Encrypt=Optional to allow non-TLS on the same endpoint.