Is there a way to limit the login to a web application based on client machine name or id. The requirement is a certain userid login should be done only from pre-determined or preset systems.
Hope this covers the queries mentioned.
I am not sure if IP address of the machine can be used as much effective as the machine name or macid may server the purpose.
Client OS can be windows or mac. Its a public facing site but a certain group of users should login from certain machines only.
The site is php, mysql and hosted on apache and linux.
Generally speaking, a web browser will only send basic HTTP headers along for the ride, in addition to a known IP address.
Assuming you even could get this information from the client system via javascript, it would not be trustable, (eg, a client could fake it).
Perhaps you can expand your question a bit?
Related
We are building a system on windows where we centrally (server) need to do fopen to either local files or remote smb resources. The idea is to authenticate in the case of remote resources before doing fopen (with unc paths).
We need to authenticate with the credentials the user (client application) supplied for this resource on that remote share. We don't want to copy any resources.
Using the Win Net Api this works smoothly since it stores the given credentials so that subsequent fopens in the same or in different processes succeed.
But there is a problem:
Many of you probably know the following message from windows when trying to connect to a smb share with different credentials then the ones used for a previous connection:
"Multiple connections to a server or shared resource by the same user, using more than one user name, are not allowed. Disconnect all previous connections to the server or shared resource and try again."
See http://support.microsoft.com/kb/938120 for the defined limitation and possible "work arounds".
Since we have a central server application running as a service ('Local System' account) we hit this limitation with having already two different users :).
Closing the previously established connection to allow for the 2nd one is not an option (ongoing processing).
On the one hand it's great that windows caches authentication information on the other hand it's too limited.
Modifying the hosts file for each user does not look very nice.
Using smb client libraries (like libsmb++, impacket) doesn't seem to be the solution since we need "over process" authentication.
Configuring a "master" smb share user is also not wanted.
Maybe passing windows user auth tokens around is a way?
This problem is of general nature (i.e. independent of language) and I'm convinced that there are people out there who solved it (in a more or less elegant way ;))
I hope my explanation is understandable.
Thanks in advance for any hint.
felix
I'm reading about how wonderful Integrated Windows Authentication is, but there is only a few comments about how it's only good for intranets. So just to be clear, is it safe to say that this technology is not realistic for internet applications? I'm developing a desktop application that connects with SQL Server and I just can't imagine telling all my customers to configure a windows account on their home PCs according to my specifications. Am I missing somethimg because that seems quite unrealistic.
(of course, where the DBA has a close relationship with the users on an intranet, it's a different story.)
I would have to say yes, Windows Authentication is best left to intranet applications - it's ideal for any authenticated communication that needs to take place on the same network.
It sounds like you want to allow the desktop app (running on your client's machine) to directly talk with your SQL Server? I would strongly recommend against allowing direct public access, especially if you cannot lock the port down to a list of known IP addresses. Instead, consider putting WCF Web Services between the database and the desktop client.
I have an application server (webservice or remoting, not yet decided) on a remote machine and a client on the same domain. I want to authenticate the user as a domain user on the server.
I can ask the user to enter their Windows username/password and send those to the server and get the server to check them against Active Directory but I would rather not. Is there any way I can get the client to send some kind of token which the server can then use to identify which domain user is sending it a request? Obviously I want to protect the server against someone sending a fake user ID and impersonating another user.
Clarification
The client on computer A will communicate with the server on computer B. I think I will probably using .NET remoting for this communication. On the server I merely need to know the ID of the user on computer A; if the app on computer A must send the ID I need to be sure that it hasn't sent the ID of a different user.
I don't need to impersonate the other user, I merely need to know (for certain) who it is.
Are you saying that the client communicates against your server, and you need to use the client's privileges at a third server? That scenario describes The Double-Hop Problem. The blog most describes it in detail, and what can be done to circumvent it (domain modifications).
[...] you can get around the problem and use proper delegation if you set up your network to use Kerberos and set up the web server in question as trusted for delegation.
Added:
I know of no way you can identify the user on computer A. Would it be enough if it was just the user executing your program? You could use windows authentication in a domain scenario, but that would only give you the privileges used by the program to authenticate, which may differ from the actual evil user in front of the keyboard.
Added:
Your comments to this post indicates that windows authentication with impersonation would work for you. Check http://community.bartdesmet.net/blogs/bart/archive/2006/08/26/4277.aspx for code examples.
I have a site i am working on that i would like to display only to a few others for now. Is there anything wrong with setting up windows user names and using windows auth to prompt the user before getting into the development site?
There are several ways, with varying degrees of security:
Don't put it on the internet - put it on a private network, and use a VPN to access it
Restrict access with HTTP authentication (as you suggest). The downside to this is it can interfere with the actual site, if you are using HTTP auth, or some other type of authentication as part of the application.
Restrict access based on remote IP. Just allow the IPs of users you want to be able to access it.
Use a custom hostname. Have it on a public IP, but don't publish the hostname. This means make an entry in your HOSTS file (or configure your own DNS server, if possible) so that "blah.mysite.com" goes to the site, but that is not available on the internet. Obviously you'd only make the site accessible when using that hostname (and not the IP).
That depends on what you mean by "best": for example, do you mean "easiest" or "most secure"?
The best way might be to have it on a private network, which you attach to via VPN.
I do this frequently. I use Hamachi to allow them to access my dev box so they can see whats going on. they have access to it when they want , and/or when I allow. When they are done I evict them from my Hamachi network and change the password.
Hamachi is a software VPN. Heres a link to Hamachi - AKA LogMeIn
Hamachi
They have a free version which works quite well.
Of course, there's nothing wrong with Windows auth. There are couple of (not too big) drawbacks, though:
your website auth scheme is different from the final product.
you are giving them more access to the box they really need.
you automatically reimaging the machine and redeploying the website is more complex, as you have to automate the windows account creation.
I would suggest two alternatives:
to do whatever auth you plan on doing in the final website and make sure all pager require auth
do a token cookie based auth - send them a link that sets a particular token in a cookie and in your website code add quick check for that token before you even go to the regular user auth
If you aren't married to IIS, and you need developers to be able to change the content, I would consider Apache + SSL + WebDav (aka Web Folders). This will allow you to offer a secure sandbox where developers can change and view the content without having user accounts on the server.
This setup requires some knowledge of Apache so it only makes sense if you are already using Apache or if you frequently need to provide outsiders access to your web server.
First useful link I found on the topic: http://pascal.thivent.name/2007/08/howto-setup-apache-224-webdav-under.html
Why don't you just set up an NTFS user and assign it to the website (and remove anonymous access)
I heard that on Windows you can login from a web browser to the web server without going through the usual login entering username and password but using instead the credentials from Windows directly, using the NTLM protocol.
How is this achieved? Does the web server need to support some additional authentication?
Update: I'm asking for a generic web server, not just IIS. How to do that on Apache for instance?
The webserver just needs to be configured to support Windows authentication (which will be NTLM, or - better - Kerberos if both client and server are W2K or later). I believe that IIS or Apache can be configured to do that.
The browser also has to support this - at least IE does so (not sure about the others, it may be possible). edit: looks like firefox has some support for this too, and safari on MacOS
edit: for details on apache, google modules for NTLM authentication. Kerberos modules also exist. as per other answers, this really only works on an Intranet - not just because the browser needs to be in an Intranet zone (only applies to IE), but because any intervening firewall will typically stop this working, and because the necessary interdomain trusts will probably not exist. It's also a bit trickier to make work if the apache server is on UNIX, and especially if you also have Kerberos servers on UNIX in the mix, but still possible.
It will only be seamless in a specific situation; namely the webserver needs to support NTLM (for example, IIS), and it needs to be in a zone that the client is configured to trust (The "Intranet Zone" in IE parlance, unless the end user has tweaked their settings)
If your webserver and client pc's are on a network secured by Active Directory or similar, you can set 'Windows Integrated Security' in IIS on the web server for the website which automatically logs in all I.E clients (That are allowed).
As stated previously, NTLM is typically used if your back end is Windows Managed (MS Active Directory). However, there are also modules available for Apache that will tie into this: mod_ntlm.
Since this is it's own protocol, it is required that the browser is able to understand this protocol and reply to the authentication challenges. I don't know which browsers support this off hand, but my assumption would be that most do.
From my experience, kerberos is more of a prefered method, but I have not worked with it much, so unfortunately, I don't have much advise as far as that goes.
On a side note, I recall reading somewhere that the JRE also has ways of tying into NTLM on your web server in order to obtain identity information for the authenticated user. As stated previously, .NET has support for this as well.
Also, Firefox does not support NTLM by default but it can be configured using the following tut: http://www.crossedconnections.org/w/?p=89
If you set the IIS settings to require authentication then your users will need to log in to access the page. They then have any rights (if not an interface) to anything on that server that they would if they logged in the normal way (from the console).
Other than this, I am not sure what you are referring to.
Yes this is possible. It is often used in intranet applications where users are. windows uses NTLM or Kerberos to authorize the user against a central service, typically Active Directory on the windows platform. On the .NET platform the current user information can be accessed through the System.Threading.Thread.CurrentPrincipal.Identity instance.
You might also want to look into Jespa. It seems a little bit more straight forward than Kerberos but provides good ntlm sso capabilities.
I was looking for more information about Kerberos (because NTLM, even v2, become deprecated with AD 2008), and I found this article, explaining how make it work with Apache (as you mentionned it).
http://blog.scottlowe.org/2006/08/10/kerberos-based-sso-with-apache/
This question is probably outdated (or at least solved), but if it can help someone ...