Browser pops up window asking for username/password with ASP.NET app - asp.net

This application is using windows integrated authentication in IIS. No anonymous login.
It's also using an application pool defined to log on with a domain user.
If a try to browse any page, it pops up the username and password dialog box and even though I entered a valid user (including the domain administrator) it doesn't log on into the app. I keep getting the username/password dialog. If I logon locally (in the IIS box), it works OK.
Also, if I change the application pool to use Network Services, it works OK.
The domain user is already a member of the local IIS_WPG group in the IIS box.
Am I missing something here?

If you use a domain account for the Application Pool you have to run a series of scripts on the domain controller. So, apparently it's not recommended to use a domain account, rather a local server account. Microsoft has this issue documented on a case:
http://support.microsoft.com/default.aspx/kb/871179

I suspect the NTFS file persmissions on the .aspx files don't allow the users you are logging in as the needed access to read/execute them. What are the file permissions on the files you are trying to view? What do your authorization and authentication elements in web.config look like?

This sounds like it's related to the privilges assigned to the domain user. i.e. whether they, or indeed the server, are permitted to impersonate the user that is logging in. Or, something regarding "Trusted for delegation" in the server's settings in AD. Either way, you'll probably get a better response on serverfault =)

Try entering the same user of the appPool as the anonymous user (Web Site Security tab)

I had the same user/pwd Popup problem in Svr 2003.
I solved it by CHECKING ANONYMOUS ACCESS in directory security of DEFAULT WEB SITE.
It promps you if you want to also affect your sites you click OK.
That did it.

Related

"401 Unauthorized" on a directory

I assume this is an IIS error, as this doesn't happen if I run the project on my local machine.
I have my stylesheets at ~/Content/css
Any files in that directory won't load on the page, and when I navigate to them directly, I get a server error:
401 - Unauthorized: Access is denied due to invalid credentials.
You do not have permission to view this directory or page using the credentials that you supplied.
This only happens with that directory, I have no problem accessing any other files. Is there something I need to do in IIS7 to stop this?
Open IIS and select site that is causing 401
Select Authentication property in IIS Header
Select Anonymous Authentication
Right click on it, select Edit and choose Application pool identity
Restart site and it should work
It is likely that you do not have the IUSR_computername permission on that folder. I've just had a quick scan and it looks like you will find the information you need here.
If that isn't the case, are you prompted for your username and password by the browser? If so it may be that IIS is configured to use Integrated authentication only, as described here.
Open IIS
select site where you are facing the problem
Select Below
- Right click on Anonymous Authentication and click on edit and follow below
You do not have permision to view this directory or page using the credentials that you supplied.
This happened despite the fact the user is already authenticated via Active Directory.
There can be many causes to Access Denied error, but if you think you’ve already configured everything correctly from your web application, there might be a little detail that’s forgotten. Make sure you give the proper permission to Authenticated Users to access your web application directory.
Here are the steps I took to solve this issue.
Right-click on the directory where the web application is stored and select Properties and click on Security tab.
Click on Click on Edit…, then Add… button. Type in Authenticated Users in the Enter the object names to select., then Add button. Type in Authenticated Users in the Enter the object names to select.
Click OK and you should see Authenticated Users as one of the user names. Give proper permissions on the Permissions for Authenticated Users box on the lower end if they’re not checked already.
Click OK twice to close the dialog box. It should take effect immediately, but if you want to be sure, you can restart IIS for your web application.
Refresh your browser and it should display the web page now.
Hope this helps!
You need to check the folder permissions on your server and check that the account that you are using to run your application has access to that folder.
For me the Anonymous User access was fine at the server level, but varied at just one of my "virtual" folders.
Took me quite a bit of foundering about and then some help from a colleague to learn that IIS has "authentication" settings at the virtual folder level too - hopefully this helps someone else with my predicament.
In our case it was Windows-integrated authentication specified in the app's web.config
BUT the windows-auth module was not installed on the IIS machine at all.
Just adding another possible reason.
Another simple fix I found was to delete the local IIS site (from within IIS Manager) and then re-create the virtual directory from the "Properties" of your web project in Visual Studio.

Receiving login prompt using integrated windows authentication

I have a .NET 3.5 application running under IIS 7 on Windows 2003 server and cannot get integrated windows authentication working properly as I continue to get prompted for a login. I have set Windows Authentication to enabled in IIS with all other security types disabled and my application web.config file authentication/authorization is set up as:
<system.web>
<compilation debug="true" strict="false" explicit="true" targetFramework="3.5" />
<authenticationmode="Windows"/>
<authorization>
<deny users = "?" />
</authorization>
</system.web>
With this setup, I'm expecting behind the scene verification of the Windows user to allow access and deny anonymous users. However, what I'm getting is a Windows login pop-up when I try to access the site.
I have been troubleshooting this issue for a few days now and cannot figure out the problem. Based on posts with similar problems, I confirmed my URL does not include any periods, double checked that my IE settings are set to Enable Integrated Windows Authentication, and also added my URL to my intranet sites, but still getting the pop-up.
To troubleshoot it further, I enabled Anonymous Authentication in IIS and modified my web.config file to which lets me right in and then added Response.Write(System.Security.Principal.WindowsIdentifity.getcurrent().user.name.toString()) to try to see what user is being used in the authentication. The result I'm getting is IIS APPPOOL\myapp which is obviously the IIS application pool for my application.
I really appreciate any help anyone can provide so that I'm still using only windows authentication but don't get the pop-up and the windows authentication is performed against the actual Windows user.
Thanks.
Additional note after troubleshooting further:
Just noticed that when the login fails and the Windows login prompt displays again, it is showing the username that attempted to login as "SERVERNAME"\"USERNAME" which led me to believe it was trying to validate the user against the server vs. the domain. To confirm this, I created a local user account directly on the app server with the same username and password as the network domain user and tried to login again. The result was that I received the login prompt again but when I entered the username and password this time, I was able to successfully login. The network user and app server are on the same domain so really not sure why IIS authentication is pointing to the local app server accounts and not to the domain accounts. I realize this is an IIS question at this point so posting on forums.iis.net as well but appreciate any advice anyone may have since have been troubleshooting this for days.
I have a Windows 2008 server that I'm working on, so my answer is not completely the same as what the OP has on a Windows 2003 server.
Here is what I did (recording this here so I can find it later).
I was having this same issue:
In my Web.config file, I had this section:
<system.web>
<authentication mode="Windows" />
<authorization>
<allow users="*" />
<deny users="?" />
</authorization>
</system.web>
Under IIS, all of these seems to be solved under the Authentication icon.
Edit Permissions: Make sure your ASP.NET account has permission. Mine was not originally added.
Now go into the features of Authentication:
Enable Anonymous Authentication with the IUSR:
Enable Windows Authentication, then Right-Click to set the Providers.
NTLM needs to be FIRST!
Next, check that under Advanced Settings... the Extended Protection is Accept and Enable Kernel-mode authentication is CHECKED:
Once I did this, I went back to my web application, clicked the Browse link, and logged in without having to provide my credentials again.
I hope this proves beneficial to many of you, and I hope it is useful for me later as well.
Just for other people's benefit. If the error is a 401.1 Unauthorized and your error code matches 0xc000006d, then you're actually running into to a security "feature" that blocks requests to FQDN or custom host headers that don't match your local machine name:
Follow this support article to fix the issue:
https://webconnection.west-wind.com/docs/_4gi0ql5jb.htm (original, now defunct: http://support.microsoft.com/kb/896861)
From the support article, to ensure it doesn't get lost:
The work around is a registry hack that disables this policy
explicitly.
To perform this
configuration manually find this key in the registry on the server:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Lsa
and edit or add a new key:
DisableLoopbackCheck (DWORD)
then sent the value to 1 to disable the loopback check (local
authentication works), or to 0 (local authentication is not allowed).
Or more easily you can use Powershell:
New-ItemProperty HKLM:\System\CurrentControlSet\Control\Lsa -Name
"DisableLoopbackCheck" -Value "1" -PropertyType dword
It looks like
recent builds of Windows 10 (1803 and later?) also require this
configuration setting in order to authenticate locally.
This one took me awhile because everyone else's comments here failed to help me. I found this article and it fixed it!
I had a similar issue whereby I wanted to protect only a certain part of my website. Everything worked well except in IE. I have both Anonymous and Windows Authentication enabled.
For Anonymous, the Identity is set to the Application Pool identity. The problem was with the Windows Authentication. After some digging around I fired up fiddler and found that it was using Kerberos as the provider (actually it is set to Negotiate by default). I switched it to NTLM and that fixed it.
HTH
Daudi
Add permission [Domain Users] to your web security.
Right click on your site in IIS under the Sites folder
Click Edit Permissions...
Select the Security tab
Under the Group or usernames section click the Edit... button
In the Permissions pop up, under the Group or user names click Add...
Enter [Domain Users] in the object names to select text area and click OK to apply the change
Click OK to close the Permissions pop up
Click OK to close the Properties pop up and apply your new settings
If your URL has dots in the domain name, IE will treat it like it's an internet address and not local. You have at least two options:
Get an alias to use in the URL to replace server.domain. For example, myapp.
Follow the steps below on your computer.
Go to the site and cancel the login dialog. Let this happen:
In IE’s settings:
Don't create mistakes on your server by changing everything. If you have windows prompt to logon when using Windows Authentication on 2008 R2, just go to Providers and move UP NTLM for each your application.
When Negotiate is first one in the list, Windows Authentication can stop to work property for specific application on 2008 R2 and you can be prompted to enter username and password than never work. That sometime happens when you made an update of your application. Just be sure than NTLM is first on the list and you will never see this problem again.
This fixed it for me.
My Server and Client Pc is Windows 7 and are in same domain
in iis7.5-enable the windows authentication for your Intranet(disable all other authentication.. also No need mention windows authentication in web.config file
then go to the Client PC .. IE8 or 9- Tools-internet Options-Security-Local Intranet-Sites-advanced-Add your site(take off the "require server verfi..." ticketmark..no need
IE8 or 9- Tools-internet Options-Security-Local Intranet-Custom level-userauthentication-logon-select automatic logon with current username and password
save this settings..you are done.. No more prompting for username and password.
Make sure , since your client pc is part of domain, you have to have a GPO for this settings,.. orelse this setting will revert back when user login into windows next time
WindowsIdentity.GetCurrent is correct: you should get the APPPOOL user. This is because the ASP.NET process, which is executing your code, is the current identity. If you want it to return the user hitting the site's identity, you'll need to add the following line in your web.config:
<identity impersonate="true" />
This causes the process to assume the identity of the user requesting the page. All actions will be performed on their behalf, so any attempts to read folders on the network or access database resources and the like will mean the current user will need permissions to those things. You can read more about impersonation here. Note that depending on how your web/database server topology is set up, you may run into delegation issues with impersonation turned on.
But your original issue is that it appears the identity cannot be determined and you're getting a login popup. I'll note that you do not need the <deny> block if you have disabled anonymous authentication in IIS. We never include it (except in special <location> blocks and such) so I would say you might try removing it and trying again. Everything else sounds right, though.
You didn't specify what user is running the application pool in IIS. Is it a custom account or is it the default one? If it is custom, is it a domain account or a local account on the web server? Custom accounts can sometimes require a few more steps, such as registering a SPN. Also, it may be a problem with the custom account not having permission in AD for resolving the incoming user's account.
You might also check the IIS logs to see what response is being returned. It'll most likely be a 401, but it should have a sub number after it like 401.2 or something. That sub-number can sometimes help determine the root problem. This KB article lists five.
Can be browser related. If you are using IE, you can go to Advanced Settings and check you the "Enable Windows Integrated Authentication" checkbox is checked.
In my case the authorization settings were not set up properly.
I had to
open the .NET Authorization Rules in IIS Manager
and remove the Deny Rule
In our Intranet the issue was solved on the client side by tweaking settings in security as shown here. Either of the check boxes on the right worked for us.
I just solved a similar problem with an ASP.Net application.
Symptoms:
I could log in to my app using a local user, but not a domain user, even if the machine was correctly joined to the domain (as you say in your Additional Note). In the Security event viewer, there was an event with ID=4625 "Domain sid inconsistent".
Solution:
I found the solution here. The problem was that my test machines where cloned virtual machines (Windows Server 2008 R2; one Domain Controller, and one web server). Both had the same machine SID, which apparently caused problems. Here is what I did:
Remove the web server from the domain.
Run c:\Windows\System32\Sysprep\Sysprep.exe in the VM.
Reboot the VM.
Join the web server to the domain.
You loose some settings in the process (user preferences, static IP, recreate the self-signed certificate), but now that I have recreated them, everything is working correctly.
I also had the same issue. Tried most of the things found on this and other forums.
Finally was successful after doing a little own RnD.
I went into IIS Settings and then into my website permission options added my Organizations Domain User Group.
Now as all my domain user have been granted the access to that website i did not encounter that issue.
Hope this helps
I tried the above IIS configuration tricks and loopback registry hack, and I reviewed and recreated app pool permissions and a dozen other things and still wasn't able to get rid of the authentication loop running on my development workstation with IIS Express or IIS 7.5, from a local or remote browsing session. I received four 401.2 status responses and a blank page. The exact same site deployed to my IIS 8.5 staging server works flawlessly.
Finally I noticed markup in the Response Body that was rendered blank by the browser contained the default page for a successful log in. I determined that Custom Error handling for ASP.NET and HTTP for the 401 error was preventing/interfering with Windows Authentication my workstation but not the staging server. I spent several hours fiddling with this, but as soon as I removed custom handling for just the 401 error, the workstation was back to normal. I present this as yet one another way to shoot your own foot.
I was having this issue on .net core 2 and after going through most suggestions from here it seems that we missed a setting on web.config
<aspNetCore processPath="dotnet" arguments=".\app.dll" forwardWindowsAuthToken="false" stdoutLogEnabled="false" stdoutLogFile=".\logs\stdout" />
The correct setting was forwardWindowsAuthToken="true" that seems obvious now but when there are so many situations for same problem it's harder to pinpoint
Edit: i also found helpful the following Msdn article that goes through troubleshooting the issue.
Have you tried logging in with your domain prefix, e.g. DOMAIN\Username? IIS 6 defaults to using the host computer as the default domain so specifying the domain at logon may solve the problem.
add to registry
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Lsa solved my problem.
Create the Local Security Authority host names that can be referenced in a NTLM authentication request.
To do this, follow these steps for all the nodes on the client computer:
Click Start, click Run, type regedit, and then click OK.
Locate and then click the following registry subkey:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Lsa\MSV1_0
Right-click MSV1_0, point to New, and then click Multi-String Value.
In the Name column, type BackConnectionHostNames, and then press
ENTER.
Right-click BackConnectionHostNames, and then click Modify.
In the Value data box, type the CNAME or the DNS alias, that is used
for the local shares on the computer, and then click OK.
Note
Type each host name on a separate line. If the
BackConnectionHostNames registry entry exists as a REG_DWORD type,
you have to delete the BackConnectionHostNames registry entry. Exit
Registry Editor, and then restart the computer.
Source: Error message when you try to access a server locally by using its FQDN or its CNAME alias after you install Windows Server 2003 Service Pack 1: Access denied or No network provider accepted the given network path
For what it's worth, I did not need to restart after making the change on Windows Server 2019.
Windows authentication in IIS7.0 or IIS7.5 does not work with kerberos (provider=Negotiate)
when the application pool identity is ApplicationPoolIdentity
One has to use Network Service or another build-in account.
Another possibility is to use NTLM to get Windows Authenticatio to work (in Windows Authentication, Providers, put NTLM on top or remove negotiate)
chris van de vijver
I had the same problem cause the user (Identity) that I used in the application pool was not belowing to IIS_IUSRS group. Added the user to the group and everything work
In my case the solution was (on top of adjustments suggested above) to restart my/users' local development computer / IIS (hosting server).
My user has just been added to the newly created AD security group - and policy didn't apply to user AD account until I logged out/restarted my computer.
Hope this will help someone.
I encountered the same credential prompting issue, and did a quick search and nothing on the internet would fix it. It took some time to find the problem, a silly one.
In IIS -> Advance Setting -> Physical Path Credential (is empty)
As soon as i added a machine ID (domain/user) that has access to the VM/server, the password prompting would stop.
Hope this helps
I got the same issue and it was resolved by changing the Application pool identity of the application pool under which the web application is running to NetworkService

WIndows Authentication not working

Newly installed IIS on a clean windows Server 2008 R2. Installed all security option. Then for the default web site authentication, enabled windows authentication and disabled all others. Then when access the default page iisstart.htm, it should give me a popup for authentication message.
but when I access the test page like: http://localhost/iisstart.htm, there is no popup. same as enabled Anonymous Authentication.
How to fix it?
I think your webservice is accessing files via your app pool identity, remove this user from the security access list on the file.
If you go to "localhost", then IE will see this as part of the "Intranet Zone". In the "Intranet Zone", IE will by default automatically send your current credentials to sites that use "Windows Authentication".
The result is that everything is probably working correctly.
First of all make sure you check if the app pool user can access the files of the website (NTFS security settings). See: IIS7 Permissions Overview - ApplicationPoolIdentity
After that (and double checking that only Windows Authentication is enabled in IIS) take into account that your URL must not contain dots! You can make an extra binding (see: https://technet.microsoft.com/en-us/library/cc731692(v=ws.10).aspx) that contains only letters and numbers and then add that binding to your local hosts file (open a text editor as administrator and then edit the file hosts in C:\Windows\System32\drivers\etc) to check.

authentication mode=Forms - so why am I getting a Windows Login prompt?

I have authentication mode set to forms in my asp.net web.config but am still getting a windows login prompt when i browse to the website.
Could authentication mode be set elsewhere, in IIS for example? My site runs on IIS 6.
Thanks.
This could be because the permissions on the folder that is being served is not allowed to be accessed by the user running the web site
I have had issues where the authentication was set to forms and the directory security was set to allow anonymous, but some resources (images in my particular case) did not have the proper permissions to allow the anonymous user to read them.
The effect is that the user was prompted to login so that the graphics could be displayed, after which the form was displayed and the user logged in (again) with the intended form.
Sounds like windows permissions problem.
Windows permissions will always override anything that you have set up in aspnet.
I would start by looking at "anonymous access" permissions in IIS admin, then work your way through the file system.
You have configured anonymous access in IIS Administrator, but the IIS user does not have permission to access the filesystem, defaulting to the login dialog to authenticate as Windows user.
As it happens a colleague updated my machine to .NET Framework 3.5 SP1 whilst I was away. So I compiled my project and released onto the server which does not have SP1 installed and the above happened.
I've installed SP1 on the server and it's working fine now.
Thanks for all your input.
Just to clarify : the login popped up because the application was unable to load a file due to the problem described in the following: Link

Checklist for IIS 6/ASP.NET Windows Authentication?

I've been having trouble getting my ASP.NET application to automatically log users into the Intranet site I'm building. No matter the googling or the experimentation I applied, there is always a login box displayed by IE7.
I've got Windows authentication mode set in the Web.config, disabled anonymous access and configured the correct default domain in IIS, but it's still asking the user to log in and, more annoyingly, the user is required to provide the domain too (DOMAIN\auser), which is causing problems with non-technical visitors. Thank Zeus for password remembering functionality.
I'm not the network administrator so it's possible that something about Active Directory is set up incorrectly, or it could just be me missing something very simple. Please note that I don't want to impersonate the user, I just need to know that the IPrincipal.Name property matches that of a valid record in my user database, hence authenticating the user to my application.
To this end, it would be very useful to have a checklist of all configuration requirements for AD, ASP.NET and IIS to work together in this manner as a reference for debugging and hopefully reducing some user friction.
It sounds like you've covered all the server-side bases--maybe it's a client issue? I assume your users have integrated authentication enabled in IE7? (Tools -> Internet Options -> Advanced -> Security). This is enabled by default.
Also, is your site correctly recognized by IE7 as being in the Local Intranet zone? The IE7 default is to allow automatic logon only in that zone, so users would be prompted if IE thinks your site is on the internet. I believe using a hostname with a dot in it causes IE to place the site into the Internet zone.
Open Active Directory Users and Computers MMC snap in
Expand computers section from TreeView (left side)
Check if the computer is registered in your domain.
Also, you have to login with a domain account on that computer, otherwise that authentication box will be shown.
In IIS, enable annonymous access and allow the web.config to handle user authentication.

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