Prevents auto (windows) authentication when browing intranet bound to Active Directory - c#

Whenever I run my MVC web application which uses Windows Authentication from Visual Studio, I get authenticated to my real domain account without any prompting.
The problem is I want to run a few test and need to connect with other accounts as well.
But despite I tried a lot of thing (tried several browsers, cleared hisotry, cookies, etc. and even tried removing a few credentials from the Seven "Credential Manager") I always and always get auto authenticated withouth any prompting (or warning or whatever that could help me cancel that).
How can I prevents this or at least authenticate myself with another account?
Note: There's no logout button on the website.
EDIT (obsolete)
I tried Private Browsing as someone (who removed his comment?!) suggested. I still get auto-authenticate but this time I don't see the same exact output.
Where I usually see my login on the page (Chrome, IE, FF) I here see my full name.
So, that changes something, but I don't know what and it still doesn't allow me to authenticate myself as someone else.
EDIT
NVM that previous edit, it was a side effect of an unrelated operation I did before (It just took a restart to have a visible effect).

To make Internet Explorer asks credentials every time you open an intranet page follow this steps:
Tools->Internet Options->Security-> Select "Local intranet" and go to "Custom level...".
After that go all the way down in the option list and change the option of "Logon" under "User Authentication" to "Prompt for user name and password.

I managed to change user, I don't know if every step I used were necessary but here's what I did that eventually allowed me to "logout".
Switch to IIS Server instead of VS Dev server
Close all browsers
Close all runnin ASP.Net Dev server
Reset IIS (iisreset)
Launch Debug (which start a FF window)
Now if I repeat the 3 last step, I can change user with no problem.

Related

ASP.NET and IIS impersonate not working [duplicate]

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

Why does windows authentication prompting credentials popup

I am using windows authentication for my intranet application which was developed in ASP.NET MVC 4.0.
In Web.config file, i set authentication mode="Windows" and in IIS Enabled Windows Authentication and disabled Ananymous and impersonation is disabled.
Everythng working fine in local, but when i deployed it to windows server 2012 using IIS 8.5 it was prompting credentials popup for first time page load. even if i enter correct credentials its not worked. then i clicked cancel for 3 to 4 times page loaded without issues. If i close the browser and reloads the same url its not asked for credentials. after sometime used the same url this time its asked for credentials.
This issue is happening randomly and am able to reproduce the issue when i refresh the page continuously for 10-15 times.am using IE 11 and google chrome browsers.in both browsers same issue.
As per my requirement it should not display the popup for credentials as it is a intranet application.
Please help me on this, i was trying to fix from last two weeks but no solution yet.
We were just working on this exact issue. It appears that a Windows update caused this issue. We were seeing problems in Exchange Web Services, Autodiscover, LDAPS, basically anything that touched IIS.
The KB is: KB3179575. We also removed KB3177723 just in case.
Hope this helps
In my experience, that generally happens when authorization fails. The user is authenticated, because they are logged into their machine, but they are not in a required role or are otherwise not authorized to view the resource. The popup is a chance to switch to an account that does have access.

ASP.NET MVC Windows Authentication is displaying login prompt instead of logging me in

Based on this article I've created a basic ASP.NET MVC site using the Visual Studio 2013 Intranet Site template with the default settings and changing nothing.
When running the site in debug mode instead of logging me in and displaying my domain\username, I am getting prompted to enter my username/password in a Authentication Required dialog.
I was under the impression, since I am already authenticated against the domain, I should be logged straight into the application using my AD account without having to enter in anything. When I do try explicitly entering my AD name or a local user account, nothing is accepted.
EDIT
If I type in my username/password with Firefox I am authenticated, but not with Chrome and IE.
Any ideas?
What you're encountering is something that's frustrated me about windows authentication for a long time. Internet explorer has a feature called pass-through authentication that authenticates you automatically when using windows auth. Other browsers have work arounds: https://addons.mozilla.org/en-US/firefox/addon/integrated-auth-for-firefox/ .
It's up to the sys admins to implement those measures for the other browsers, but nobody ever does, so we get stuck typing in our full usernames and passwords in every browser but IE.
What you can do is follow this approach : http://blogs.msdn.com/b/chunliu/archive/2010/09/21/creating-a-custom-login-page-for-windows-authentication.aspx
Not nearly as simple as enabling windows auth, or even implementing forms auth for that matter, but consider a scenario where you want infrastructure to manage permissions and administer user accounts, or if you want to expose your login page globally without exposing AD.
IE won't pass credentials to a site unless it's in the intranet security zone or the same domain. You can add your site to IE's list of trusted sites using
Internet Options > Security > Trusted sites > Sites
Chrome takes its trusted site settings from IE's settings, so once you add to IE, it should also work in Chrome
Check with your IIS (Internet Information Server) Manager and see if your application has the right permissions for the user.
Go to the "Connections" panel on the left-hand side
Under "Sites", navigate to your application or folder holding the application
Right click and select "Edit Permissions..."
Go to the "Security" tab
Check if your Windows ID or Windows Group (if multiple users) have the correct permissions to this site under the "Group or user names" box
If the user or group is not there, click on the "Edit" button and then click the "Add" button
Also check if "Windows Authentication" is enabled and both "Anonymous Authentication" and "ASP.NET Impersonation" are disabled for the application on the IIS.

How to Elevate Role in ASP.net From anonymous to windows auth?

I have a few websites which allow both anonymous and window auth users at the same time. Basically if you hit the site with IE or Webkit based browsers on a windows system, the server instantly recognizes your active directory user and group.
In the past I've provided a link to a windows auth only page which allows the current user to login, or bounce back to where they started.
I find the management of this kind of frustrating as I need to make certain that IIS has the correct security settings for that single page after every deployment.
Is there a better way for me to allow a user to elevate from anon to authenticated?
There is no other way to do that elevation automatically. The server can't know that the current user is a Windows user and elevate them, or automatically redirect them to the Windows auth only page. On the other hand, if every user will get through the Windows auth only page, all of them which are not inside the domain will see the challenge/response dialog box (user + password).
As for the management part of making sure that this special page has the correct security settings, you can (and should) automate the check somehow. For example, by querying the IIS metabase for that setting when the application starts (in Global.asax) and if the setting is not there, log it as an email message or so.
Personally I prefer a different attitude - a special "integration/deployment" page which contains a series of tests against my application so I can make sure everything's set up correctly on the server, i.e. NTFS write permissions to certain folders, availability of the SMTP server set in web.config to send emails through, etc.
Note: You're using Windows authentication along with anonymous access. Just keep in mind that if you consider implementing Forms Authentication in the future, a misarchitecture (I don't know if by design or due to a flaw) of IIS 7 does not allow you to set the app to be Forms Authentication and set one specific page to be Windows Authentication. The override just doesn't work and it's very frustrating.
Good luck!
OK, I figured out a fairly nice way to do this...however it's not as elegant as I had hoped since it doesn't work across applications.
Basically, if you create a single page within your Anon + Integrated Auth IIS6 website or virtual directory, let's call it auth.aspx, then you can use this page to prompt authentication.
Go into IIS settings and specify that auth.aspx is Integrated Auth ONLY (no anon). Then create a hidden iframe somewhere on your page. I then created a simple JavaScript action to update the src attribute of the iframe to the auth.aspx page. This forces the browser to try and authenticate using NTLM. Once you enter valid credentials you've successfully elevated your current user beyond the generic anonymous user.
One final touch was to then include a Response.Redirect into the auth.aspx which reloads the current page. Assuming your ASP.net session tokens are set correctly, the page will reload and the user will be authenticated.

What permissions are needed to start a service through ASP.NET?

I was wondering what privileges I needed to let a user start a service on our server.
The situation is as follows, some people on our website can start a certain service on the server (Windows 2008 and IIS7). The way that worked so far with me was specifying the application pool I created with my user account (the impersonate method from msdn doens't work for some reason). Now however I want to change that user account to a user account who only has the priviliges to start and stop a service (and everything that is needed to get him to do that).
The website is written in ASP.NET and C#. I use the ServiceController to start and stop my services.
Which privileges should I assign to that user?
EDIT: I just want to clear some things up here. I managed to get this thing working through the Application pool (although it doesn't work through debugger). But it only works with a user that is part of the Administrators group which isn't what I want. I want to specify a special user that will only be able to start and stop the service through the website. So what privileges do I need? Please be specific.
EDIT 2: I found out why my service wouldn't start in the debugger. I didn't run Visual Studio with administrator rights. I feel so stupid right now.. Anyway the question still stands as I still need my special user with the correct permissions.
Any comment will be appreciated!
Kind regards,
Floris Devriendt
You have to set identity impersonate to true in your web.config and if you are using windows authentication then need to set that up in IIS. if you are using a WCF service in between you may have to look at Impersonation in WCF.
(Terminology gripe) - you shouldn't be looking at privileges, since those apply across a machine as a whole. You should be looking at permissions.
There's an answer here about allowing remote users to start and stop a service. You may need to run the same steps to allow the account your website is under the specific permissions, that is:
Copy the IA users permissions on the scmanager, to allow a non-interactive user to access the service controller, and
Add appropriate permissions for your user against the specific service.
Both of these actions use the sc command line tool. Hopefully, you can crib enough together for your specific circumstances. Something like:
sc sdset scmanager D:(A;;CC;;;AU)(A;;CCLCRPRC;;;IU)(A;;CCLCRPRC;;;SU)(A;;CCLCRPWPRC;;;SY)(A;;KA;;;BA)(A;;CCLCRPRC;;;S-1-5-3-3127463467463)S:(AU;FA;KA;;;WD)(AU;OIIOFA;GA;;;WD)
where S-1-5-3-3127463467463 is the SID for the website account, and:
sc sdset Alerter D:(A;;CCLCSWLOCRRC;;;AU)(A;;CCLCSWRPLOCRRC;;;PU)(A;;CCDCLCSWRPWPDTLOCRSDRCWDWO;;;BA)(A;;CCLCSWRPWPDTLOCRRC;;;SY)(A;;CCLCSWLOCRRCWPRP;;;S-1-5-3-3127463467463)S:(AU;FA;CCDCLCSWRPWPDTLOCRSDRCWDWO;;;WD)
whwere Alerter is the name of the specific service, and S-1-5-3-3127463467463 is again the SID for the website account.
(Not sure whether to break up these commands to make them more readable on SO - they need to have no line-breaks when running in the command line)
you have to give the right for strating your service to the user that you are using for the application pool.
Click Start, point to Settings, click Control Panel, and then double-click Administrative Tools.
Double-click Services
On the Log On tab, click Local System Account, and then click Apply.
On the General tab, click Start to restart the service.
Quit the Services tool.

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