MVC 5 Bypass Forms Authentication for Windows Authenticated users

Question

I already have a website written using MVC 5 and it uses form authentication using SQL Server.

Now is it possible that I can bypass Forms Authentication for users that are already on office network. Also I want to keep track of user and apply rules similar to Forms Authentication. Thanks.

Answer 1

Yes you can do that. Here's the code to check user in domain. First get the domain name and try to verify user with domain. If this fails then proceed to forms authentication.

 public static string DomainControllerName { get; private set; }
 public static string ComputerName { get; private set; }
 public static string DomainName { get; private set; }
 public static string DomainPath
 {
            get
            {
                bool bFirst = true;
                StringBuilder sbReturn = new StringBuilder(200);
                string[] strlstDc = DomainName.Split('.');
                foreach (string strDc in strlstDc)
                {
                    if (bFirst)
                    {
                        sbReturn.Append("DC=");
                        bFirst = false;
                    }
                    else
                        sbReturn.Append(",DC=");

                    sbReturn.Append(strDc);
                }
                return sbReturn.ToString();
            }
 }
        public static string RootPath
        {
            get
            {
                return string.Format("LDAP://{0}/{1}", DomainName, DomainPath);
            }
        }
Domain domain = null;
DomainController domainController = null;
try
{
    domain = Domain.GetCurrentDomain();
        DomainName = domain.Name;
        domainController = domain.PdcRoleOwner;
        DomainControllerName = domainController.Name.Split('.')[0];
        ComputerName = Environment.MachineName;
}
finally
{
if (domain != null)
       domain.Dispose();
if (domainController != null)
       domainController.Dispose();
}


try
{
using (PrincipalContext ctx = new PrincipalContext(ContextType.Domain))
    {
                DirectoryEntry root = new DirectoryEntry(RootPath, txtUserName.Text.Trim(), txtPassword.Text);
                DirectorySearcher search = new DirectorySearcher(root);

            search.SearchScope = SearchScope.Subtree;
            search.Filter = "(sAMAccountName=" + txtUserName.Text.Trim() + ")";
            SearchResultCollection results = search.FindAll();

            UserPrincipal userP = UserPrincipal.FindByIdentity(ctx, txtUserName.Text.Trim());

            if (userP != null && results != null)
            {
                //Get the user's groups
                var groups = userP.GetAuthorizationGroups();
                if (groups.Count(x => x.Name == ConfigurationManager.AppSettings["UserGroup"].ToString()) > 0)
                {
                    //Successful login code here
                }
                else
                {
                    //"Access Denied !";
                }
            }
            else
            {
                //"User Name or Password is incorrect. Try again !"
            }
        }
    }
    catch
    {
        //"User Name or Password is incorrect. Try again !"
    }