Use SQL Integrated Security and IIS Windows Authentication - asp.net

We have an internal asp.net web application which has ASP.NET authentication and Windows Authentication enabled so that users can be logged in as soon as they connect to the website using their domain credentials (this is a requirement that we cannot change).
We are currently looking to upgrade our SQL database and understand that SQL Authentication is less secure than integrated security (e.g. https://msdn.microsoft.com/en-us/library/bb669066(v=vs.110).aspx). Currently we use SQL Authentication.
We could easily change the connection string to run using integrated security, however IIS presents the user as the domain user connected to the website (e.g. domain\greg) instead of the service (domain\WebsiteServiceUser), because IIS impersonates the user. This impersonation is needed to access their Exchange Mailbox, files and other things.
If we were to go down this path, we would have to add logons for every user (using AD groups) to SQL Server. This is possible, but in itself presents a new security issue - users would be able to create a SQL connection outside of our web application and run whatever queries they like against the database. All of our authorization could be bypassed.
Is there a way to connect to SQL using Integrated Authentication using the user that the AppPool runs as (Domain\WebsiteServiceUser) instead of connecting as the currently logged on user (Domain\Greg)?

Related

DB connection string between two servers by Windows Authentication

I have two servers, let's say they are APPSVR (ASP.NET) and DBSVR (SQL Server). Currently, the application running smoothly with database connection using SQL Server authentication with User Id and Password.
In the future, it must be changed with Windows Authentication Integrated Security=True. I have tried to change this but can't worked (DB connection failure).
We have domain controller also and both server in the same domain. I am not sure which one that must be configured in our environment (Domain/SQL Server/IIS Manager). What's the right procedure to do this?
Is your asp.net application already running with domain user authentication?
Do you need per user login for SQL server because you set up the
access right on domain user rather than create your own access right
system on your asp.net application?
Why i am asking you this? Because You need to consider the differences between web application and desktop application. In web application, the web server contact the sql server not the user pc.
So this complicate the setup if you want the web server to use the windows authentication to login to sql server then you need to set up the web server to somehow masquerade as the domain users. You also need to consider the scenario if user are accessing the web application from the internet.
I suggest using strong application only password for sql server connection using local user rather than domain Users. For access right you can simply create a new table to store domain user login id and their access right. This set up still allow login to web application using the domain Users but the database connection is not. The Advantage is you can minimize the access to simply few or even one user application only user you need to maintain in sql server rather than every domain Users that need to be registered on sql server if you use windows authentication.
If you still need the Windows Authentication set up than you can see the info here.
We recently had to change over to using Windows Auth instead of a SQL Account to access the DB from our ASP site. The trick is to have the application pool start up with the same domain account you use to access the SQL Server and then you can just change your connection string to use Integrated Security.
The process is shown here:
https://thycotic.force.com/support/s/article/Using-Windows-Authentication-to-access-SQL-Server-Secret-Server

User Database Permissions - Windows Authentication

Is it possible to pass Windows domain credentials (users) from their browser directly to MSSQL for database authentication?
Still learning ASP.NET and EF, but I have a working webapp that uses a static DB connection string in my webconfig. I'm using Windows Authentication via IIS to control access to the website, but I need to support read/write permissions in the database, per user.
It would be great if I could just use AD and assign permissions directly in SQL server, instead of having to maintain my own user table and permissions/roles.
It is possible with impersonation. You can configure it to pass the same credentials from the IIS to SQL Server, however, if SQL server is physically in another server, you might need to give some permissions to users. I have done this years ago, but couldn't do it again recently.

Connect to SQL Server with EF using windows credentials of final user

I have an application developed in ASP.NET MVC using Entity Framework / Sql Server 2008
Actually, connections to the database are made with the "sa" account.
Is it possible to use, instead of "sa" the windows final user credentials ?
This would be helpful to control more efficiently the security limitations of each user.
I use, in my application windows authentication.
Thank's !
It is possible but whole your system must run inside windows domain, users must have domain accounts and your system infrastructure must be enabled for Kerberos delegation (belongs to ServerFault). The reason is that you have two hoops in the system - first user authenticates from his client machine to your web server and then web server delegates user credentials to database server. If client computer, web server and database server are different machine Kerberos delegation must be enabled (if db and web runs on the same server you should be fine without Kerberos). Your web application will have to use impersonation and your connection string will have to use windows integrated security.
Also using end user credentials will reduce performance of your system because EF will have to maintain separate connection pool per user. Administrator of SQL server will have to give access for every single user (or user group) using your application.

SQL Server Integrated Authentication Mode

I was wondering when using Windows Authentication mode in a connection string from a web application. Application itself is using Windows Authentication for authorization. Which account will be used to login to SQL Server.
Is't the web application pool account?
User account who logged in to web application using windows auth?
Any other account?
Application is running under Win Ser 2008 64 bit and IIS 7. Application pool account is Network Service.
It depends on how you configure it. From http://msdn.microsoft.com/en-us/library/ms998292.aspx and http://msdn.microsoft.com/en-us/library/bsz5788z.aspx ...
ASP.NET applications do not impersonate by default. As a result, when they use Windows authentication to connect to SQL Server, they use the Web application's process identity. With this approach, your front-end Web application authenticates and authorizes its users and then uses a trusted identity to access the database. The database trusts the application's identity and trusts the application to properly authenticate and authorize callers. This approach is referred to as the trusted subsystem model.
The alternative model referred to as the impersonation/delegation model uses the original caller's Windows identity to access the database. This approach requires that your ASP.NET application is configured to use impersonation. See the section "Impersonation / Delegation vs. Trusted Subsystem" in this document.
So depending on how you have configured it, it could use either the app pool account (not when not using impersonation) or the account of the logged-in user that is using the web application (when using impersonation).
See http://msdn.microsoft.com/en-us/library/134ec8tc.aspx for impersonation information.
It's the application pool user who connects to the database, if you specified Integrated Security in your connection string.
The problem that i was having was that my application pool account in SQL Server needed to be set to the db_owner role before it worked. I spent a long time trying to figure this out.
I was using Windows Authentication, Windows 7 home premium, and IIS all on the same computer. I'm posting this in case someone else run into a similar problem. The book i used did not say to use db_owner but the reader and writer accounts instead.

How do I allow anonymous access to my IIS site, but use Windows Authentication to connect to SQL Server?

What I want to do is:
Allow anonymous users to access my ASP .NET site.
Use Windows Authentication for the site to access Sql Server. It will log in to Sql Server with a domain account set aside especially for the site (and preferably do everything under the same account).
Every article on the Web tells you to do this:
<authentication mode="Windows"/>
<identity impersonate="true"/>
in Web.config. However, I gather that this is only if you want users to log in with Windows Authentication. It has nothing to do with the server logging in to SQL Server (except that the combination of the above 2 implies that users' authentication will also be used to connect to the database). Is this correct? Given that my Windows account has access to files on the server and the database which the site is connecting to, this seems hard to test....
It seems that if I:
set the App Pool Identity to the domain account
enable Anonymous Access on the site using the domain account
use a connect string with Windows Authentication
then the site will connect to SQL Server via Windows Authentication. Also, it will use the domain account as long as impersonation is off. Is this correct?
in Web.config. However, I gather that
this is only if you want users to log
in with Windows Authentication. It has
nothing to do with the server logging
in to SQL Server
This is partially true. The impersonated account will be used to logon SQL server if delegation is setup properly. You didn't see this because in most of the environment, delegation needs to be explicitly setup. Delegation is a more powerful form of impersonation and makes it possible for the server process (in your case, IIS process) to access remote resources (in your case, SQL server) while acting as the client. For more information, you can google ASP.NET Delegation. I said it's partially true because in some simple environment, you don't even need any special configuration. The delegation is just working. For example, if you have SQL server running on the same machine as the IIS server. Another case is that you have your IIS server running on an Active Directory domain controller (very rare). In these two cases or on a machine with delegation configured properly, your above statements will be wrong.
It seems that if I:
set the App Pool Identity to the
domain account
enable Anonymous
Access on the site using the domain
account
use a connect string with
Windows Authentication
then the site
will connect to SQL Server via Windows
Authentication. Also, it will use the
domain account as long as
impersonation is off. Is this correct?
Yes, this is correct.
Given that my Windows account has
access to files on the server and the
database which the site is connecting
to, this seems hard to test....
It's easy to test if you have two domain accounts (or one domain account and one local account). Set the App Pool identity to use your DomainAccount1. Grant only DomainAccount1 to have permission to access your database. Access your web app on another machine using another accound (either domain account or local account). Test if the web app can properly access your database.
If I'm following you correctly, you are right; You do not want to use impersonation/authentication to do what you want to do. Set the App Pool identity appropriately, and assure that user account has appropriate access to SQL Server.
Instead of using a Windows Account you can create a separate Sql Login i.e. a username/pwd and use that in the connection string instead.

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