Forms authentication against multiple providers (SQl and AD) - asp.net

We have an application that is for both internal users and external customers. We would like to authenticate against AD for the internal users and against sql membership for the external customers. Has anyone taken a similar approach? Also what is the best way to authenicate against AD when in a DMZ? I would rather have a proxy of some sort that is in the dmz and handles authentication against the AD DCs on our internal network. Any suggestions?
TIA,
Kevin

We have a similar situation. Our Internal users go against AD the external guys against an ADAM store. Different than your database approach, but similar in that they have two user stores. Our authentication against AD occurs in the secure zone, the web servers in the DMZ make a webservice call into the secure zone for authentication. Don't know what you are rally looking for, but your approach sounds ok.
EDIT to answer comments:
The ADAM store is not synced with the database.
Basically there were two providers that the webservice was configured to use, one for each store. I fact, there were three for a period of time when users were migrated from the legacy system. To determine which store a user was in, the application simply asked the most common provider first (ADAM in our case) and if the user did not exist, it would move to the next provider.
The endpoint was the webservice, inside the firewall, running on a the middle tier server. That server did run IIS, so technically it was a webserver, but actually our middle tier server as it did not serve up any pages or host anything other than a few webservices.
So it sounds like you have 2 types of external users. Ones that are really internal users (in AD) and ones that are truely external (in DB). This is not very elegant, but you could ave 2 login screens, one for each. Don't publish the internal users external login screen to anyone but them, and publish the real external login screen to teh world. A little hacky but it would work. Otherwise, you login would process will need to identify the type of user.

Related

Retrieving all users and roles in a .NET Web Application through ADFS

We have a hosted .NET web application (Windows Server 2012 R2 environment) and we need to provide Single sign-on (SSO) to users from a corporate LAN environment. We have used ADFS to enable SSO and it is working as expected thus when a user hits our web application login page URL he is authenticated against ADFS and is automatically logged in to the application.
We have an additional requirement where we need to obtain a list of all users, their groups, email addresses some additional information periodically from their Active Directory so that this information can be bulk loaded into our web application however since ADFS is implemented we do not have direct access to the Active Directory.
Is it possible to connect to ADFS and obtain a list of all users, their email addresses etc. programmatically?
If the above is not possible then what is the recommended approach for this kind of a setup?
Thank you.
No, this is not possible. There is no such API because with SAML and WS-Federation, users can come from anywhere. This does not have to be AD, technically it's possible create a "Log in with Facebook" implementation.
What would you need the information for? The user's claims contain all information which you might need (user name, e-mail address, group memberships).
If you really need that information about all users in your application, perhaps ADFS is not the solution you are looking for.
As Alex mentioned above - the way it works, ADFS does not provide any way of importing data from the AD or other trust stores. It just gives you the information that are carried over with the token.
In case you need more information, you should extend the number of claims being issued by ADFS. You can then collect the information - when the user comes for the first time, use the data from the token and fill the profile. If it is returning user - update the information if necessary.
The other solution (but I wouldn't say it's recommended - rather a workaround) would be to implement custom solution for importing information from AD to your application. I'd say it's fair as long as you use your local AD for reading this data. In the moment you decide to extend the access to third party (e.g. partner company), which might be using different identity provider, which doesn't have to be backed by Active Directory any more - you find yourself in tough spot.

ASP.Net Membership in SQL vs. Windows

I just inherited a project for a small company. This is a completely internal web application and the current model for authentication and roleManager is based on their domain policies. Well, I work from home and little experience with windows authentication, and I definitely am not part of a domain.
So, in order to "fake" the same sort of setup that they have, is it a good idea to setup ASP.Net Membership in SQL Server? And I think that you can setup roles in there, too, which I could use to create a one-one mapping of roles in SQL to what they have on their network (there are 5 or so, that's all), correct?
Then, when I push changes to their system, I would just overwrite my web.config with one specific to them, that basically sets Membership auth and rolemanager to user their network setting instead of my SQL ones. This would let me test locally but they could keep their domain driven security model.
Am I crazy, and these 2 things just aren't analogous?
The two things aren't the same so you're not going to be able to work on it as you are thinking. The membership provider would always require a login process and other user management, and the code to check the role membership and user account details would be completely different.
My suggestion would be to see if they have VPN access to their LAN and get them to set you up an account on the domain.

host .net 3.5 webservice on dynamic ips / domains

hey guys i have written a small webservice which allows users of a company (lets call it xyz) to login to xyz's website remotely via my iphone app (without ever going on xyz's official website to login)
after logging these users programatically to xyz's website, i can allow my users to do many authenticated tasks xyz offers
since xyz does not offer apis for this i was forced to hijack xyz's login cookies from my webservice to allow users to use all the authenticated features
at no point of time am i saving xyz users username or password and use https for my webservice to ensure safety n security of users
however i have got an email from xyz asking me to shut down my webservice otherwise face legal action. if i do that my users would be very unhappy to loose so many cool features of my iphone app
i wanted to know the best way to host my webservice on some offshore server which has elastic / dynamic ip addresses with completely different patters (so xyz cant block a particular range of ips or even domain names)
i have heard amazon provides elastic ips - can they be used for such scenario
or can someone help me come out with a better solution
webservice is asp.net 3.5 based
You should negotiate with them and find out what they don't like about your service.
You can then modify it to be friendlier to them.
Alternatively, you can get rid of your webservice and connect to their control panel directly from the iPhone.
Looks like you are asking for help on doing illegal things. Not a smart thing to do on something as public as this.
Best advice I can give is bite the bullet and take your service down.

Using Active Directory to authenticate users in a WWW facing website

I'm looking at starting a new web app which needs to be secure (if for no other reason than that we'll need PCI (Payment Card Industry) accreditation at some point).
From previous experience working with PCI (on a domain), the preferred method is to use integrated windows authentication which is then passed all the way through the app to the database using kerberos (so the NT user has permissions in the DB). This allows for better auditing as well as object-level permissions (ie an end user can't read the credit card table).
There are advantages in that even if someone compromises the webserver, they won't be able to glean any/much additional information from the database. Also, the webserver isn't storing any database credentials (beyond perhaps a simple anonymous user with very few permissions for simple website config)
So, now I'm looking at the new web app which will be on the public internet. One suggestion is to have a Active Directory server and create windows accounts on the AD for each user of the site. These users will then be placed into the appropriate NT groups to decide which DB permissions they should have (and which pages they can access).
ASP.Net already provides the AD membership provider and role provider so this should be fairly simple to implement.
There are a number of questions around this - Scalability, reliability, etc... and I was wondering if there is anyone out there with experience of this approach or, even better, some good reasons why to do it / not to do it.
Any input appreciated
Having used ADAM in a project, I found it to be bear. Documentation for developers can be sparse, it has quirks that differentiate it from full AD and, most importantly, I could not get a straight answer from MS as to whether it will be fully supported in the future. The impression I got was that ADAM was the bastard child and that the new Federated services (ADFS) was where they wanted people to go. Just moving the ADAM store from one member server to another was a pain. Now that said, my issues with ADAM had to do with development against and maintenance of the store, It definitely has the ability to scale and it was reliable. That said there are times when you need to delve into 80th level spells of LDAP/Directory magic to figure what it is or is not doing.
For a public facing site, AD/ADAM might be overkill IMO. You could use alternate MembershipProviders like the SqlMembership provider to get the good level of security with respect to credentials. If you wanted to go further, you could use database encryption (SQL Server at least has this ability built-in) to encrypt information that falls into the PII (Personally Identifiable Information) arena and of course encrypt the backups. The advantage that a database backed authentication store has is that you have all the tools that your database product provides to scale out, do backups, control access and so on.
EDIT: Let me add, that with .NET you can setup your site so that it runs under a Windows user and connects to the database using Windows Authentication (assuming the db supports it). Thus, no credentials need to be stored in a config file. However, if you had to store credentials for whatever reason, you can then use DPAPI to encrypt the credentials in the config file.
ADDITION In response the question about securing encryption keys you have a couple of choices. The first is to simply hash the credit card numbers. That greatly simplifies any problems with access to the data however, it means that the customer would have to re-enter their card number for each purchase. If you want to remember the customer's card number, then you move into a new realm of maintenance of the decryption keys. In this scenario, you absolutely should use Windows Authentication to the database and look into SQL Server 2008's Extensible Key Management feature which lets you hook-in a third-party key management program into SQL's encryption functionality. In this way, only the website user would have access to the keys used for decryption. There are other solutions to ensure that the website cannot be compromised. The greater worry is that someone gets a copy of the database undetected. Here's a link on using SQL Server to be PCI compliant:
Deploying SQL Server 2008 Based on Payment Card Industry Data Security Standards (PCI DSS) Version 1.2.
couple ideas
Run AD/AM - Active Directory Application Mode.
It scales well. It's the same core code as AD. Similar management capabilities. Solid reliability. Works with the ASPNET AD Membership Provider.
And it's included in Windows.
Also consider exploring a federated identity system, via ADFS 2.
unlike AD/AM, this approach is fairly leading-edge. The final version of the ADFS v2 server is not yet available from Microsoft, but it is at "release candidate" stage. If you have the stomach to be an early adopter, ADFS2 holds the possibility to employ a federated identity approach. That means you could accept identity tokens from a variety of existing sources: a google sign-in, a yahoo sign-in, any OpenId source, and use that as the identity on your site. Users would not have to "register" and authenticate to you. Instead, your site would honor the identity and authentication provided by some trusted third party, and perform authorization based on that identity.
This is not a direct answer but having a AD user account means you need a windows CAL for that user. Another way would be to issue client certificates to user and map client certs to AD users in IIS.
You might also consider AzMan with SQL store available from Windows 2008 onwards or the open source netsqlazman.

ASP.NET Application to authenticate to Active Directory or SQL via Windows Authentication or Forms Authentication

I am in the process of writing an application that will need multiple forms of authentication.
The application will need to support authentication to Active Directory, but be able to fail back to a SQL Membership Provider if the user is not in Active Directory. We can handle the failing to the SQL Provider in code based on the username provided because the username will be a different format than the Active Directory username.
Is this even possible? What I mean is, can I use membership and use both ActiveDirectoryMembershipProvider and SqlMembershipProvider together or will I have to roll my own?
Another additional added complexity is that I would like to automatically authenticate my internal users based of Windows Authentication back to AD, but use Forms Authentication for users not on our internal network, or users that are using the SQL Provider.
These will most likely be separate servers, one internal, and the other external so I have a lot of planning to do to figure out the data replication, and how I will authenticate the AD users if they hit the outside server etc.
I am wondering what thoughts are out there as I start down this road. Is what I am wanting to do even possible without me rolling my own, or is there a way to mesh these together?
Thanks for the reply.
The reason I asked originally was because I was able to get this specific senerio working about 7 years ago using IIS to authenticate and then passing back the credentials to a Lotus Domino Server Web App. If the user was not authenticated via the Windows Authentication/ISS then Domino would handle the authentication. This was what I was looking to do here, but really couldn't think of a way to make it work in IIS.
As for the rest of your reply, I think you are on to the way that I will need to take. I have thought this through and tossed it around in my head a lot. The application will be somewhat different on the two servers anyway since there is going to be limited access to the data on the external server anyway. The fact that so much is going to be different already I may just treat these as two applications, thus negating the need to use two types of authentication in the same application anyway.
I am playing around with the idea already of writing my own authentication/login window for the external server, and if the user trys to log in with their AD credentials on the external server I will be able to detect that and redirect them to the internal server. If they are not on the local network or VPN'd in they will simply not get access. This part still has some thought process to go though so I am not sure.
As an additional thought - is there a way to pull just enough of AD into a SQL database to allow me to authenticate users to the SQL database from the external server using their AD credentials, without creating any security issues? I hope I am clearly typing what I am thinking....
Thanks again!
Tim
This is the way I've handled a similar situation based on this info:
Configured the application to use Forms authentication.
Set the LoginUrl to a page called WinLogin.aspx.
In WinLogin.aspx, use Request.ServerVariables["LOGON_USER"] to get the username then call FormsAuthentication.RedirectFromLoginPage( authorizedUserName, false ) to log them in. I guess you can manually check Active Directory as this point as well.
Create an html page that redirects to a page called Login.aspx
Login.aspx is your standard username/password login.
In IIS, Enable Integrated Authentication and Anonymous on the entire site, but deny anonymous access to WinLogin.aspx.
In IIS, set your 401 errors to the page created in step 3.
What basically happens is that when an unauthenicated user hits the site, they're redirected to WinLogin.aspx. Since anonymous is turned off, integrated security makes a check. If that passes, your custom code in WinLogin can run. If the integrated security check fails, a 401 error occurs. Your custom 401 page redirects to Login.aspx where the user can log in using their username and password with the SQL provider.
As far as I know, Web Applications are configured to use either Windows Authentication or Forms Authentication, but not both. Therefore, I do not believe it is possible to automatically authenticate internal users while requiring others to enter a username / password.
You could authenticate to Active Directory or a SQL user store via Forms authentication by using a custom provider. However, the AD users would still need to enter their username and password. Although I've never combined these two methods, I have used Forms authentication to authenticate against both sources at one time or another.
With that said, I think you may want to consider reducing the "flexibility" of your system. If you have an external facing server and an internal facing server, you could simply change the provider configuration on each copy of the application to go against a different source. Then, you could configure the internal one to use Windows (automatic) authentication and the external one to use Forms authentication.
IMHO, I believe that internal users should not be using the external server to access the application. If they are, they should have a user account stored in SQL, completely separated from their AD account. Basically, when someone accesses the application externally, they are acting as an external user, irregardless of their physical location.
Well, it is possible to use ActiveDirectoryMembershipProvider and SqlMembershipProvider, but this requires you design your log on page with your own code instead of the Login controls.
About the mix authentication (Windows and Forms), as far as I know only IIS 7 makes it easy and clean. See this post for details,
http://mvolo.com/blogs/serverside/archive/2008/02/11/IIS-7.0-Two_2D00_Level-Authentication-with-Forms-Authentication-and-Windows-Authentication.aspx

Resources