C# / .NET 8 `HttpClient` Desktop & Master Tool Integration

using System.Net.Http.Headers;
using System.Security.Cryptography;
using System.Text;

public sealed class DaVinciCloudApiClient(HttpClient http, string apiKey)
{
    public async Task<string> SubmitJobAsync(string binPath, string brand, string family, string servicesCsv, CancellationToken ct = default)
    {
        using var form = new MultipartFormDataContent();
        await using var fs = File.OpenRead(binPath);
        var fileContent = new StreamContent(fs);
        fileContent.Headers.ContentType = new MediaTypeHeaderValue("application/octet-stream");
        form.Add(fileContent, "file", Path.GetFileName(binPath));
        form.Add(new StringContent(brand), "ecu_brand");
        form.Add(new StringContent(family), "ecu_family");
        form.Add(new StringContent(servicesCsv), "services");

        using var req = new HttpRequestMessage(HttpMethod.Post, "https://www.davincideluxe.fr/api/v1/cloud/jobs") { Content = form };
        req.Headers.Authorization = new AuthenticationHeaderValue("Bearer", apiKey);
        using var res = await http.SendAsync(req, ct);
        res.EnsureSuccessStatusCode();
        return await res.Content.ReadAsStringAsync(ct);
    }

    public static bool VerifyWebhook(byte[] rawBody, string signatureHeader, string whsec)
    {
        var mac = HMACSHA256.HashData(Encoding.UTF8.GetBytes(whsec), rawBody);
        var expected = "sha256=" + Convert.ToHexString(mac).ToLowerInvariant();
        return CryptographicOperations.FixedTimeEquals(
            Encoding.UTF8.GetBytes(expected),
            Encoding.UTF8.GetBytes(signatureHeader ?? string.Empty));
    }
}