I have summarized the solution below for your reference..But incase you refer this page again for some reason be sure to go through the comments we have discussed so that you get a clear picture of why each point here has been discussed..
If you want to restrict the user to read/write/delete/modify in all the tables in your db then you can do it using code.
Create a User Mapping Table...Map the user with the entities he/she can use in the User mapping table. Allow the user to access those entities in for which the user has permissions....
Please check the folllowing links...You might be able to get some idea..
http://www.codeproject.com/Articles/265870/Bypass-Forms-Authentication-to-Use-Active-Director
http://www.codeproject.com/Articles/15877/ADAM-and-LDAP-Client-Net-LDAP-Access-Control-for-A
For Windows Authentication issue
Please verify the below site...
http://www.codeproject.com/Articles/94612/Windows-Authentication
Regards,
Dinesh Kumar.V.