.NET Framework 4.8.1 WinForm在Win10与Win11的HTTP2请求异常问题

我使用.NET Framework 4.8.1开发了一款应用，在开发所用的Windows 11电脑上运行正常，但在两台全新安装并更新的Windows 10电脑上出现异常。

一、背景信息 #

应用通过HTTP2协议向远程CloudFlare服务器发送HTTP请求以获取令牌。

发送给服务器的请求：

{Method: POST, RequestUri: 'https://this.is.confidential/json/gov/v10/Api/CreateApiKey', Version: 2.0, Content: System.Net.Http.StringContent, Headers:
{
  Content-Type: text/plain; charset=utf-8
}}

Windows 11电脑上收到的服务器响应：

{StatusCode: 200, ReasonPhrase: '', Version: 2.0, Content: System.Net.Http.NoWriteNoSeekStreamContent, Headers:
{
  Cache-Control: no-store, no-cache
  Date: Tue, 13 Dec 2022 19:37:43 GMT
  Server: cloudflare
  Set-Cookie: __cf_bm=W5wDtxsixycI1_5G5fdgdfJGkVCX5nT9tzG8-1670960263-0-AfqDRz1MMF67L/ntDOShg3Jz3GZxMo/UtCYReTfDIJl1g0vQ/MfeVa5C8/PxQLtucWoYvV5nYGEyyuN/r19aWWo=; path=/; expires=Tue, 13-Dec-22 20:07:43 GMT; domain=.thisisconfidential.com; HttpOnly; Secure; SameSite=None
  Vary: Accept-Encoding
  access-control-allow-origin: *
  x-duration: 33.200026
  cf-cache-status: DYNAMIC
  cf-ray: 779127ecadedf11c-CDG
  Content-Type: application/json
}}

Windows 10电脑上收到的服务器响应：

{StatusCode: 403, ReasonPhrase: '', Version: 2.0, Content: System.Net.Http.NoWriteNoSeekStreamContent, Headers:
{
  Cache-Control: no-store, must-revalidate, no-cache, max-age=0, private, post-check=0, pre-check=0
  Date: Tue, 13 Dec 2022 13:18:28 GMT
  Server: cloudflare
  Set-Cookie: __cf_bm=oKXtpXuiUmH5MeEA8n67RTG33dfZhv5Th5c3ZX0PAUSw1oA-1670937508-0-AX+aH9+MYxwNqOdbMZCmhg35ByjwgaTmtJdditJ7K1xEU1ex7au/PyiJ4JbCImQvICHQPcr+QJijZSeYfKme3/o=; path=/; expires=Tue, 13-Dec-22 13:48:28 GMT; domain=.thisisconfidential.com; HttpOnly; Secure; SameSite=None
  x-frame-options: SAMEORIGIN
  referrer-policy: same-origin
  cf-ray: 778efc668ed6d07b-CDG
  Content-Length: 16
  Content-Type: text/plain; charset=UTF-8
  Expires: Thu, 01 Jan 1970 00:00:01 GMT
}}

二、代码实现 #

为在.NET 4.8.1中使用HTTP2，自定义了一个HttpHandler类：

Imports System.Net.Http

Public Class Http2CustomHandler : Inherits WinHttpHandler
    Protected Overrides Function SendAsync(request As HttpRequestMessage, cancellationToken As Threading.CancellationToken) As Task(Of HttpResponseMessage)
        request.Version = New Version("2.0")
        Return MyBase.SendAsync(request, cancellationToken)
    End Function
End Class

发送请求时调用该类的代码：

Using wclient As New HttpClient(New Http2CustomHandler())
    Dim url As String = "https://this.is.confidential.com/json/gov/v10/Api/CreateApiKey"
    With wclient
        .BaseAddress = New Uri(url)
        .DefaultRequestHeaders.UserAgent.Add(New Headers.ProductInfoHeaderValue("govAgent", "3.6.15"))
        .DefaultRequestHeaders.Accept.Clear()
        .DefaultRequestHeaders.Accept.Add(New Headers.MediaTypeWithQualityHeaderValue("text/plain"))
    End With

    Dim req = New HttpRequestMessage With {
        .RequestUri = New Uri("https://this.is.confidential.com/json/gov/v10/Api/CreateApiKey"),
        .Method = HttpMethod.Post,
        .Content = New StringContent($"login={login}&password={password}&gov={gov}&long_life_token=true", Encoding.UTF8, "text/plain")
    }

    Dim response As HttpResponseMessage = Await wclient.SendAsync(req)
    Dim jsonString = response.Content.ReadAsStringAsync().Result

三、测试信息 #

• 将包含所有必要DLL的Release文件夹复制到Windows 10电脑上运行应用，出现问题
• 尝试发布并安装应用，同样出现问题
• 将VB.NET项目移至Windows 10电脑编译运行，请求仍失败
• 两台Windows 10和开发用的Windows 11均已更新至最新版本，且都安装了.NET Framework 4.8.1

更新 #

实际是Windows 10与.NET Framework 4.8/4.8.1结合WinHttpHandler存在BUG，使用HTTP 2.0版本时无法正常工作，但改用HTTP 3.0版本即可兼容CloudFlare WAF。

内容的提问来源于stack exchange，提问作者SuperJudeFruit