Jeremy
Jeremy

Reputation: 46350

SQL Server: Checking role membership

In SQL Server I have a many to many relationship between items and active directory groups. I want to build a query, that based on a supplied active directory user, I would be able to query for all items associated to an active directory group if the user is a member of the group.

I went down the road of using IS_Member, but that only works for the currently connected user. The stored procedure will be called by an asp.net web app, which currently connects with a specific sql user account. I don't think I can connect using integrated authentication and impersonation in the web app, because I don't beleive our infrastructure configuration will allow delegation from the user machine, through the web server, then to the db server (3 hop issue).

What can I do here?

Upvotes: 0

Views: 590

Answers (2)

user2620038
user2620038

Reputation:

The issue you describe is a classic double-hop scenario, which can be (eventually) resolved through the painstaking process known as Kerberos configuration. A lazier workaround would involve passing the credentials from the asp.net application as a variable to a SQL query on your database.

If the SQL Server has the LDAP Server configured as a linked server, you could rewrite your stored procedures to accept the user as an input variable and check to see if the user is a member of an AD group before proceeding. Consider incorporating OPENQUERY into your stored procedures as shown below:

CREATE PROCEDURE CheckAccess
@CurrentUser varchar(max)
AS
IF @CurrentUser IN
(
SELECT CN  
FROM OPENQUERY(ADSI,'<LDAP://DC=Your,DC=DomainComponent,DC=com>;(&(CN=*)
(memberOf=CN=YourADGroupName,OU=Your,OU=OrganizationalUnit,OU=Name,DC=Your,DC=DomainComponent,DC=com));CN')
)
THEN
SELECT 'Authorized User'
ELSE
SELECT 'Unauthorized User'
END

If you can, consult with your LDAP admins to make sure you get the group's correct domainComponents and organizationalUnits to tweak the OPENQUERY. One drawback to this is that it can take a while to query your AD group, obviously depending on the size of membership. It can be a pain, but as long as your app can pass the user as a variable, you can leverage OPENQUERY or even query sys.database_principals to check their access.

Upvotes: 0

Quantum Elf
Quantum Elf

Reputation: 752

Write a C# or VB.NET .exe that queries AD and populates a table in the database with all the users/groups and call it from a SQL job that you execute daily. Then just use the synched up table data to do the comparisons. This way you can avoid all the other complexity of trying to do it on the fly. Group membership doesn't change that often. Even if something changed in AD you can just manually run your "sync job" and things would be ok. You can use Windows.Identity() or whatever it is from ASP.NET to check the username.

Upvotes: 1

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