ASP.NET - authentication against multiple domains - c#

My website can be access from many domain (a my own blog engine). So, how i can cross authentication?
I'm using: IIS7, C#, asp.net membership, form authentication.

If you are using Active Directory (assuming that is what you refer to as domains), you can simply configure multiple ActiveDirectoryMembershipProvider sections and use the asp:Login control templates, add a dropdown for the domains you want to authenticate against, and on the OnAuthenticate event of the Login control, set the selected AD membership provider.
For different providers like SQL Server membership provider, I'm not sure I understand what the issue is. Can you elaborate?
I'm going to take a guess here after having tried to read your question a couple of times again. If with 'multiple domains' you mean you have multiple websites (multiple fully qualified domain names), and you want to use the same SQL Server datastore to authenticate users against, and run the same website, the solution would be to point the appropriate DNS A record to the IP address of the original hosting server.
Any decent domain registrar should allow you to change the DNS record.
However, Forms Auth creates a cookie, and you will not be able to read the cookie from a different domain than that you are on because of obvious security issues, so in that case you're stuck.
The only possibility I can see is that you're passing some encrypted identity in a querystring, but that is very, very dodgy, as you would want to make sure there's a minimal validity time limit on it as it opens up a right can of worms (security holes). Probably not recommended.
Crikey, that's a long way of saying "No, you can't - securely."
If are talking about sub domains and not about different top level domains, then you can actually do it, see this post.

Related

ASP.NET Manual user authentication

I am working for the DOD. The application they have requested is web based, and will be on their internal network. The request is for CAC authentication, which is easy enough... The remaining problem is authenticating a user. The CAC authentication is happening at the IIS level, so by the time the user gets to the application, all I am doing (or had planned on doing) is checking the ID on the CAC, and comparing it to a user table in the database. If the user exists (and has been approved), then they are off and running in the system. If they do not exist, then they are pushed to the registration screen.
Given my lack of experience with web development, I am unsure if I need to actually authenticate the user in some way beyond the CAC authentication, or if I can just manually assign roles to the user and let the roles dictate what can or cannot be done in the application. Windows authentication is not an option; while this application is internal for the military, it is accessible from different mil networks.
If I do indeed need to authenticate a user... this is where I run into trouble. I have not found anything that says there is a way to manually authenticate a user. I could use the standard ASP tables in the database, but it seems... messy... to include things that won't be used (meaning the password field would always be an empty string - why include it in the db if it isn't being used?).
Thanks in advance for any help... If there's links to where I can read more about the authentication process, those would be very much appreciated as will.
I'm working on several DOE projects that use the same idea. What we normally do for web applications is to enable Windows authentication on the app. This will allow pass-through of user credentials and keep out anyone without credentials.
I also like to add role based authorization into the mix and then use AD groups to allow/deny users on specific apps.

designing secure intranet (ASP.NET) application

I am wondering if i need to add any other kind of security on this asp.net application - web forms (available only on network domain and through VPN connection)?
Application Environment: Asp.net 4.0, Vb.net, Oracle 10g, Web Services, Window server 2003 or 2008, Hosted on domain
User Authentication Mode: Window (Not using asp.net membership)
Authentication Scenario:
Application is accessible via intranet site and system authenticates user with his system user name. On the default page system will first get the current user name (HttpContext.Current.User.Identity.Name) and then match it in the user table (oracle DB), if it is matched then store procedure will return all the access permissions (menu details) relevant to this user group. There is a user group and permission table in the oracle DB.
In the store procedure, system will also check the user permissions before any DML transaction.
Main security concern
Major: restrict people to access the information depends on their permissions. Normal user shouldn’t get access to other’s data.
Minor: We don’t want anyone to get into our system outside office network.
As Joachim says, this arrangement only supports Windows systems running on the local network. Shifting to basic authentication will allow more clients to connect but exposes the passwords on the network (effectively in clear text) without HTTPS. Forms authentication is similar.
Without server authentication, users could be redirected to a similar server without their knowledge or suffer a main-in-the-middle attack. HTTPS gives you this with the server certificate. This may not be a concern on a local network but users' hosts (in c:\windows\system32\drivers\etc) files are often vulnerable.
Without encryption, any user can sniff the information sent back and forward over the network assuming they are on the same subnet. This may be an acceptable risk for most applications but not if the information is sensitive, e.g. contains sensitive or personal information.
Consider replay attacks (see How do I prevent replay attacks? for an example) if people are performing important operations like approvals.
Consider auditing access to the database, particularly the user group and permission tables. Someone could add themselves or move them into a group, perform an operation then remove themselves. Check your pages for SQL injection and similar attacks which could accomplish this.
In summary, how likely are people to compromise or interfere with the system and how much are you willing to invest to protect it? Assuming the server can handle the load, HTTPS is a hard to go past as a first step.
Unsure what kind of ASP.Net technology you are using (MVC/Razor/Web Forms).
If you are using Web Forms, then you can immediately take advantage of ASP.NET Login Controls like LoginView Control. They work with ASP.Net Forms Authentication (with or without using ASP.net Membership). You can also take advantage of Roles.
Your intranet server should be "protected" if it's not exposed in your network publicly (in any way). Of course that's a bold statement that depends entirely on your network implementation - e.g. subnetting, internal net/no nat/route/no port forwarding, no dns, etc. This makes VPN as your only point of exposure from the outside, then you must enforce proper security policies for your VPN infrastructure - e.g. one-time passwords, client inspection, etc.
Update:
If you are using Active Directory, you can create users/groups in AD to provide access accordingly (e.g. Finance AD group can only access "finance" folder). I haven't kept abreast with browser support for NTLM outside of Internet Explorer however.
You did mention user data is in an Oracle db however(?). I'm not familiar with solutions that allow no login screen access (to network resources) using a db/Oracle.....
Also, that would mean one-time passwords for VPN access may not be available. Look into token based VPNs so users can still use their AD credentials but need a new token each time - this will help mitigate the "passwords in yellow sticky notes" (because you can have tighter control over tokens).

How to get one login page for multiple systems?

I have four systems running on the same server. I want to let the users to log in once for all the systems. I made one user-management system to create users and edit them.
I tried to save in the session but it didn't help.
Any suggestions? I am working on asp.net.
There are two approaches.
Most resolve around the login happening at a central site, which then returns with an identity information field (login token) that the target site uses to retreive the user.
When you go to another site, the site redirects you shortly to the central site and if you are logged in (persistent cookie) you get back the identity of you.
Alternatively you can do a lot with referrers and playing around.
YOu want to do some research on the internet - what you loo kfo is "Single Sign On".
http://www.codeproject.com/Articles/27576/Single-Sign-on-in-ASP-NET-and-Other-Platforms
has some technical discussions.
Across complete separate websites (domains) you can read up on
http://aspalliance.com/1513_Cross_Site_Authentication_and_Data_Transfer
howw to do it - obviously shared cookies will not work there.
The best way to do this is with Federated Security. If you were using Windows Authentication then you could use Active Directory Federation Services (ADFS). In this model, users reference a Web application and the principal on the current thread is checked. If the value is null then information stored in the web.config will redirect the request to a login page automatically. This is assuming there is no a Windows security context, otherwise the user can be automatically logged in.
After the user is successfully logged into the environment, the principal on the thread is populated and a set of claims are issued that are specific for that user. Since the claims are associated with the principal and not with a specific application, they can be used across the board by any claims aware application.
If you aren't using Windows Authentication, you can still accomplish the same thing, the only problem is that you cannot use ADFS. Instead, you'll have to implement your own Identity Provider to replace ADFS. The .NET Framework does provide base classes and interfaces to help you accomplish that.
I would suggest looking into ActiveDirectory or any LDAP server for single signon to access all applications. If you cannot (or do not wish to) use LDAP, you could implement similar functionality (but with more development work/time spent) with any memory/disk store. If this is not possible, please share why as it might be useful to others.
Hope this helps.

C# 4 ASP.net *NON MVC* Custom Authentication

I know this question as been asked countless times, but believe me I've searched Google for hours and got nothing. Whatever is out there, it's for MVC, which I'm not using.
My requirement is simple. I do not want to use the default authentication provided in asp.net. I would store the username/password/role in my custom SQL Server table. I'll provide 2 inputs for username/password and a button to validate. On validation, he is allowed access to the admin areas. This will only be used by admin guys at my subdomain "admin.*.com". They will use this page to add content to the website on daily basis.
How do I implement it. A tutorial link would suffice.
Is it safe for Production? I don't want some newbie hacker getting in to my site and mess it up. If not safe, what else option do I have.
Thanks,
Dev
As per our comments, given your reluctance to implement an ASP.Net Membership provider (and it is worth the time to investigate - you may not feel that it is right now, but it can be handy. I felt the same way at first, but the cost of maintaining your own code and infrastructure soon proves to be false economy) you have at least two other choices:
1) Straightforward Forms Authentication
Put all of your admin pages under a single folder, for example, /Admin, then use Forms Authentication to protect access to this folder. Only users defined in the database or Web.Config will have access to these pages. This is less flexible than ASP.Net membership, but may give you most of what you want. In terms of security, this will be as secure as your website is, is well tested, and is well documented.
2) Use Facebook OAuth
You mentioned that your use has access to Facebook. You could use Facebook to do the authentication for you. Although you wont be able to grab the username and password, you can get a token back, that you can then validate against a known permission set. This is a lot more work than 1) though and will tie you to potential future changes in the Facebook API. However, it also benefits from being well tested, and secure, but you have little to no control over the actual user information.
As an aside, please also consider being nicer to Google!
You can create your own custom membership provider which has the features you are looking for.asp.net membership provider
Its best to use the tried and tested method for security purposes. Remember you can customise any providers including role providers or even create your own unique providers.
Here is an example how to LDAP authentication using ASP.NET 1.1. The logic may still be applicable or can be adapted to later versions of ASP.NET, although I have not tested it.
Using the built-in membership providers, or implementing your own, is no guarantee that a hacker can't get access to your system. Things you'll have to consider:
encrypting data between client and server
don't store passwords in the database, not even encrypted. Hash each password its own salt, if you can.
enforce strong password entropy.
make sure session and authorization cookies are marked HttpOnly and Secure
for admin passwords, have a policy to change them frequently (like once a month)
provide means to notify administrators when someone signs in to their accounts
temporarily lock out ip address who exceeds number of requests per second and failed to authenticate
temporarily lock out users when they enter their password more then x (e.g. 10) number of times in an y number of minutes (e.g. 10).
These are just a handful of things to look for. You'll also have to concern yourself with session highjacking, javascript attacks and so forth.
Its not a trivial matter.
Writing a custom authentication handler is very dangerous. There are many ways to get it wrong and leave your website vulnerable to attack.
I also understand your complaint that Forms Authentication is extremely complicated. I was faced at a similar cross roads and decided to build my own authentication system called FSCAuth. It's BSD licensed. It's designed to be super simple and to allow for just about any database format you can image. All that must be done to set it up is implement a small 4 function interface into your database and populate a few configuration fields.

Shared User Session for Multiple ASP.NET Websites

I have been tasked with developing a single Login and Dashboard page that user can login too, the user will then be shown all the systems (we developed) that they have access based to based on some roles stored in our databases.
If they logged in we would like that "User Session" (not sure of correct terminology) to be carried to which ever system they are redirected too.
To illustrate a very rough overview of what I want to achieve:
alt text http://www.pcbg.co.za/attachment.php?attachmentid=12165&d=1268903524
Is there a way that a user can login in one site, and then carry over that login to the other sites?
Help, Advice, Link will be much appreciated.
Sorry I am not experienced at ASP.net but have a good understanding of Silverlight, C#, WPF.
Thanks in advance.
You can use the concepts of single-sign on. You can manage your session data as out-proc, i.e. in a SQL server or a State server. Here are couple of links which will give you some pointers:
ASP Allaince
MSDN
Edit: Alo look at this question in SO:
One method that I would use is that you implement your own authentication system - almost like the ASP.NET 1.x days. However, the trick is that you establish a cookie for each domain (host part of the URL) with an authentication cookie.
If all of those systems are running on the same server, I am sure you will be able to use all the FormsAuthentication methods and the Membership API. If they are not [edit: hosted on the same server], then ensure that they configured to encrypt the authentication cookies with the same keys. Implementation of this bit will be by what mileage you need to do...
One thing to notice is that you may also establish only one cookie is sent to the browser but shared by all the applications. Imagine that you have the following URL's:
dashboard.com
myapp1.dashboard.com
myapp2.dashboard.com
myapp3.dashboard.com
Setting a single cookie to the domain "dashboard.com" will send and share the same cookie to all the other domains.
The shared session states as described by the other posters will not work. The way session variables work on the server is that an unique key is generated on the server for your data storage (whatever the medium is: in proc, out of proc, SQL server). That unique key is stored in a cookie where it is sent to your browser as the host part.
I hope that gives you some insight on how to go about tackling the single sign in solution that you are making.
One way would be to use the session state service that ASP.NET provides. Basically once the user logs in, that session could be stored on a separate process (and not be a part of aspnet_wp). All your applications would need to be modified to go to that machine to fetch user authentication status. Search Google/MSDN for Session Management techniques.

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