TlsClient

TlsClient is a simple yet extensible TLS (Transport Layer Security) client library written in C#. It allows you to establish TLS connections with various configurations, including custom JA3 fingerprints, cipher suites, and application protocols.

Features

• Custom HTTP client: The CustomHttpClient class provides a custom implementation of an HTTP client. It includes methods for sending HTTP requests and handling responses.
• Support for custom JA3 fingerprints
• Configurable cipher suites
• Configurable application protocols (e.g., HTTP/1.1)
• Custom server certificate validation callback

Examples

These passes Cloudflare's TLS check

Example 1 (using TlsClient)

using var tlsClient = new TlsClient.TlsClient("example.com", 443, ja3Fingerprint);
string request = "GET / HTTP/1.1\r\n" +
                     "Host: example.com\r\n" +
                     "User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/58.0.3029.110 Safari/537.3\r\n" +
                     "Accept: text/html,application/xhtml+xml,application/xml;q=0.9,image/avif,image/webp,image/apng,#1#*;q=0.8,application/signed-exchange;v=b3;q=0.9\r\n" +
                     "Accept-Language: en-US,en;q=0.9\r\n" +
                     "Connection: close\r\n\r\n";

string response = await tlsClient.SendRequestAsync(request, TimeSpan.FromSeconds(30));

Example 2 (using CustomHttpClient)

    var ja3FingerprintString =
        "769,4865-4866-4867-49195-49199-49196-49200-52393-52392-49171-49172-156-157-47-53,0-23-65281-10-11-35-16-5-13-18-51-45-43-27-21-41-28-19,29-23-24,0";
    var ja3Fingerprint = CipherSuiteConverter.JA3FingerprintParser.Parse(ja3FingerprintString);

    var test1 = new CustomHttpClient("example.com", 443, ja3Fingerprint);
    var req = new HttpRequestMessage(HttpMethod.Get, "https://example.com/");
    req.Headers.ConnectionClose = true;
    req.Headers.Accept.Add(new MediaTypeWithQualityHeaderValue("text/html"));
    req.Headers.AcceptLanguage.Add(new StringWithQualityHeaderValue("en-US"));
    req.Headers.Add("User-Agent",
        "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/58.0.3029.110 Safari/537.3");
    var res = await test1.SendAsync(req, TimeSpan.FromSeconds(30));
    Console.WriteLine(res.StatusCode);
    Console.WriteLine(res.Content.Headers.ContentLength);
    Console.WriteLine(res.Headers.ToString());

Prerequisites

• .NET 8.0 SDK

What's Missing?

While TlsClient provides a solid foundation for establishing TLS connections, there are a few notable missing features:

• !!! It's too much broken to be used in production.
• It's not a full-fledged HTTP client: TlsClient is primarily focused on establishing TLS connections and sending raw HTTP requests. It does not provide high-level features like automatic redirection, cookie management, or response parsing.
• HTTP/2 Support: The current implementation only supports HTTP/1.1 as the application protocol. Adding support for HTTP/2 would be a valuable addition.
• Automatic Certificate Management: The library currently requires manual management of client certificates. Implementing automatic certificate retrieval and renewal would enhance usability.
• Connection Pooling: Connection pooling can improve performance by reusing existing connections for subsequent requests.
• Proxy Support: Adding support for proxy servers would increase flexibility in various network scenarios.
• Comprehensive Logging and Error Handling: Enhancing logging and error handling capabilities would aid in debugging and troubleshooting.

Contributing

Contributions are welcome! If you find any issues or have suggestions for improvements, please open an issue or submit a pull request.

License

This project is licensed under the terms of the MIT license.