C#•2y ago

[ASP.NET] Middleware Stops Controller From Receiving Login Request

These are my buttons in /Views/Login

    <form role="search" action="/Login/AddLoginCookie" method="POST">
        <button class="btn btn-dark" id="test1" type="submit">Login</button>
    </form>

    <form role="search" action="/Login/DelLoginCookie" method="POST">
        <button class="btn btn-dark" id="test2" type="submit">Logout</button>
    </form>

    <form role="search" action="/Login/AddLoginCookie" method="POST">
        <button class="btn btn-dark" id="test1" type="submit">Login</button>
    </form>

    <form role="search" action="/Login/DelLoginCookie" method="POST">
        <button class="btn btn-dark" id="test2" type="submit">Logout</button>
    </form>

These are the buttons in /Controllers/LoginController

        [HttpPost]
        public IActionResult AddLoginCookie()
        {

            Response.Cookies.Append("sessionId", "001");
            return RedirectToAction("Index", "Login");
        }

        //works even without HttpPost
        [HttpPost]
        public IActionResult DelLoginCookie()
        {
            Response.Cookies.Delete("sessionId");

            return Redirect(Request.Headers["Referer"].ToString());
        }

        [HttpPost]
        public IActionResult AddLoginCookie()
        {

            Response.Cookies.Append("sessionId", "001");
            return RedirectToAction("Index", "Login");
        }

        //works even without HttpPost
        [HttpPost]
        public IActionResult DelLoginCookie()
        {
            Response.Cookies.Delete("sessionId");

            return Redirect(Request.Headers["Referer"].ToString());
        }

This is the middleware code in program.cs

app.Use(async (context, next) =>
{
    if (context.Request.Path.StartsWithSegments("/Login/"))
    {
        await next(context);
        return;
    }

    string sessionId = context.Request.Cookies["sessionId"];
    if (sessionId == null)
    {
        
        context.Response.Redirect("/Login/");
    }
    else
    {
        await next(context);
    }
});

app.Use(async (context, next) =>
{
    if (context.Request.Path.StartsWithSegments("/Login/"))
    {
        await next(context);
        return;
    }

    string sessionId = context.Request.Cookies["sessionId"];
    if (sessionId == null)
    {
        
        context.Response.Redirect("/Login/");
    }
    else
    {
        await next(context);
    }
});

For some reason, it looks like the middleware is preventing the user from using the controller IActionMethods in /LoginController to get a session ID. But this seems to be happening anyway even though I am checking that (context.Request.Path.StartsWithSegments("/Login/")). FWIW, even

if (context.Request.Path.StartsWithSegments("/Login/AddLoginCookie/"))

if (context.Request.Path.StartsWithSegments("/Login/AddLoginCookie/"))

will not let me through to the IActionResult. What is going wrong here?

30 Replies

Kouhai•2y ago

Just change if (context.Request.Path.StartsWithSegments("/Login/")) to if (context.Request.Path.StartsWithSegments("/Login"))

surwren•2y ago

lmao it actually works why doesn't /Login/ work? technically the full url is /Login/Index, so why is .StartsWithSegments() not able to get the correct path Actually a better question would be how do I troubleshoot this because nothing appears in the call stack variables

Kouhai•2y ago

The way StartsWithSegments defines a segment is basically /Login/ is a whole segment, so /Login/AddLoginCookie/ can't match the whole segment of /Login/ Meanwhile /Login means something can come after it because it's not terminated with / Unfortunately if you don't know the behavior of StartsWithSegments it would be a bit troublesome, your best bet would be to attach a debugger and investigate which part fails btw off topic, your pfp is really cute 😅

surwren•2y ago

You mean like x64DBG? I did put in breakpoints in MSVS but it just skipped over the initial conditional

Kouhai•2y ago

No no, with a managed debugger in your IDE Were you in release build?

surwren•2y ago

I think it's development, how do I change it?

Kouhai•2y ago

You can change it from the top menu here

Kouhai•2y ago

https://learn.microsoft.com/en-us/visualstudio/debugger/media/toolbar-build-configuration.png?view=vs-2017&viewFallbackFrom=vs-2022

surwren•2y ago

Ok, I'll try it in a few min when I'm back at the pc

Kouhai•2y ago

You were probably in Debug build anyways, I thought Release might've caused it to not get hit

surwren•2y ago

hmm

surwren•2y ago

yea, I am in debug

Kouhai•2y ago

When you placed a breakpoint what happened?

surwren•2y ago

It stops at the breakpoint but the variables of the call stack don't show any helpful info whatsoever lemme grab a screenie like

surwren•2y ago

surwren•2y ago

it shows the path then it just skips and doesn't give any indication why it evaluated false on the path

surwren•2y ago

this too

surwren•2y ago

I mean I understand the solution now, but if something similar were to occur I would have no way of troubleshooting it on my own in the future 😔

Kouhai•2y ago

Oh, yeah, that would be normal StartsWithSegments only returns bool so there is no way to really know why it failed with running the code. You can however run code in an interactive code thingy (I forgot what's called 😅 ) and see what works with StartsWithSegments or if you're comfortable with reading the source code for it, you can find it on github

surwren•2y ago

I'm confused, what keywords should I look for for this interactive code thing? Or do you mean the source code/BCL for ASP.NET is on oogura

Kouhai•2y ago

Yeah, I meant ASP.NET on Github, only go that route if others fail first and you're comfortable with that 😅 Lemme just open VS and show you what I meant with interactive code thingy

Kouhai•2y ago

Kouhai•2y ago

You can evaluate different expressions in Immediate Window

surwren•2y ago

Is there some setting to activate it? My immediate window is blank

surwren•2y ago

Kouhai•2y ago

You can just type any expression you want!

surwren•2y ago

it works! thank you I have an additional question @Kouhai Why does middleware use the async syntax/keyword?

app.Use(async (context, next) =>...

app.Use(async (context, next) =>...

Is it mandatory for middlewares to use async? I feel like I am lacking some comprehension of middleware necessary to connect the dots but idk what it is

Unknown User•2y ago

Message Not Public

surwren•2y ago

Are middlewares always lambdas or is it this specific middleware?

Unknown User•2y ago

Message Not Public

Gaming

Programming

[ASP.NET] Middleware Stops Controller From Receiving Login Request