Webdav Lock request return "405 Method Not allowed" in asp .net core 6 hosted in IIS - asp.net-core

Question

I actually a migrate an old asp .net framework 4 web app to asp .net core 6.
This webapp was serving docx et xlsx files through IIS and webdav to allow end users edit directly files on the server
On the old app, the config was like that
a virtual directory on IIS to associate a virtual Path Webdav to a physical path
an IHttpModule which allow me to intercept all request on the server and add some authentication when the request point out /webdav (webdav don't support anonymous authentication)
HttpContext.Request.Headers.Remove("Authorization");
HttpContext.Request.Headers.Add("Authorization", "Basic " + base64string);
On the new app
the virtual directory is manage directly on the code (Startup)
var lOptions = new FileServerOptions
{
FileProvider = new PhysicalFileProvider(Sys.Web.AppliIs.Path_Webdav),
RequestPath = new PathString("/" + Sys.Web.AppliIs.WEBDAV_FOLDER),
EnableDirectoryBrowsing = false,
};
app.UseFileServer(lOptions);
i intercept the request to add my authentication in a custom middleware (called before the code above)
app.Use(async (context, next) =>
{
AppliGeckosSL.WriteLogDebug($"intercept {context.Request.Path}, Method : {context.Request.Method}", null);//just to log everything which arrived
var lFileInfo = lHostEnv.ContentRootFileProvider.GetFileInfo(context.Request.Path);
if (lFileInfo != null)
{
WebdavFileManager.HandleRequest(context, lFileInfo.PhysicalPath);
}
// Call the next delegate/middleware in the pipeline.
await next(context);
});
Whe i test the new code (opening a file stored in the server with word), it failed.
Whe i inspect the logs, i notice thow things :
On the IIS logs, i see my different request called by word
2022-03-23 11:20:31 ::1 OPTIONS /Webdav/ - 7520 - ::1 Microsoft+Office+Protocol+Discovery 200 0 0 47
2022-03-23 11:20:31 ::1 HEAD /Webdav/BeWise.docx - 7520 - ::1 Microsoft+Office+Existence+Discovery 200 0 0 4
2022-03-23 11:20:31 ::1 OPTIONS /Webdav/ - 7520 - ::1 Microsoft+Office+Existence+Discovery 200 0 0 5
2022-03-23 11:20:31 ::1 LOCK /Webdav/BeWise.docx - 7520 - ::1 Microsoft+Office+Core+Storage+Infrastructure/1.0 405 0 0 4
2022-03-23 11:20:31 ::1 GET /Webdav/BeWise.docx - 7520 - ::1 Microsoft+Office+Core+Storage+Infrastructure/1.0 404 0 3 2
we can see the Lock method finished in 405
We can also see the get finishing in 404 which i can't understand because the HEAD finished on 200 on the same file
The log of my middleware give me only this
23/03 12:20:32:023 [FW] intercept /Webdav/BeWise.docx, Method : HEAD
23/03 12:20:32:055 [FW] intercept /Webdav/, Method : OPTIONS
so we see the LOCK and the GET are not handle by my server
I see many solutions on this problem on this forum and others which recommand to disable webdav, solution which dont fit me because i want to use webdav
There is not a lot of documentations about .net core and webdav, im not even sure its supported.
I try to remove the virtual directory by code and set a virtual directory through IIS like the old app but still not working, in this case the lock not finish in 405 but in 401. I notice my middleware in not called, so i cant add my authentication. I suppose with this option we don't go through the asp .net core pipeline.
What do you think ? any suggestion on that ?
Thanks for your help !

Answer 1

I had some answers from microsoft, the IIS webdav module is no longer supported with .net core (they will update the docs for that because it was not clearly said). So there is no way i will be able to achieve what i want.
My solutions now :
implement myself the webdav protocol
buy a licence to IT HIT WEBDAV Server Engine
thanks anyway for your answers, the subject is closed