Using AD groups to authorise access to pages using IIS Windows Authentication - ASP.NET Core 2.1[Answered] RSS

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  Shadow_Kitte...

  Member

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  45 Posts

  Using AD groups to authorise access to pages using IIS Windows Authentication - ASP.NET Core 2.1

  Feb 07, 2019 09:50 AM|Shadow_Kittencorn|LINK

  I am trying to use standard AD groups (not azure) to control access to an intranet site. I can successfully get the username using

  User.Identity.Name

  and pull the groups using 

  PrincipalSearchResult<Principal> groups = user.GetAuthorizationGroups();

  When I started I figure it would be easy to lock down access using 

  [Authorize(Policy = "DOMAIN\\Domain Admin")]

  However the User groups for authorisation don't seem to inherit from AD (I am guessing they did in a different version of ASP.NET?). I get access denied no matter what.

  What is the simplest way of doing this?

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  Xing Zou

  Contributor

  2230 Points

  731 Posts

  Re: Using AD groups to authorise access to pages using IIS Windows Authentication - ASP.NET Core...

  Feb 08, 2019 07:28 AM|Xing Zou|LINK

  Hi Shadow_Kittencorn,

  You could use Policy-based authorization to authenticate only users from a Active Directory group have access to the page.Make sure you have set correct AD group's name.

  In startup.cs ConfigureServices:

  services.AddAuthorization(options =>
              {
                  options.AddPolicy("ADRoleOnly", policy => policy.RequireRole("DOMAIN\\Domain Admin"));
  
              });

  In controller:

  [Authorize(Policy = "ADRoleOnly")]
   public class HomeController : Controller

  Another method is to write a custom Policy Authorization handlers to check User's all ADGroups and check if they contains your desired group name.

  You could refer to follow steps:

  1.Create CheckADGroupRequirement(accept a parameter)

  public class CheckADGroupRequirement : IAuthorizationRequirement
      {
          public string GroupName { get; private set; }
  
          public CheckADGroupRequirement(string groupName)
          {
              GroupName = groupName;
          }
      }

  2.Create CheckADGroupHandler

  public class CheckADGroupHandler : AuthorizationHandler<CheckADGroupRequirement>
      {
          protected override Task HandleRequirementAsync(AuthorizationHandlerContext context,
                                                         CheckADGroupRequirement requirement)
          {
              //var isAuthorized = context.User.IsInRole(requirement.GroupName);
  
              var groups = new List<string>();//save all your groups' name
              var wi = (WindowsIdentity)context.User.Identity;
              if (wi.Groups != null)
              {
                  foreach (var group in wi.Groups)
                  {
                      try
                      {
                          groups.Add(group.Translate(typeof(NTAccount)).ToString());
                      }
                      catch (Exception e)
                      {
                          // ignored
                      }
                  }
                 if(groups.Contains(requirement.GroupName))//do the check
                  {
                      context.Succeed(requirement);
                  }
              }
  
              return Task.CompletedTask;
          }
      }

  3.Register Handler in ConfigureServices

  services.AddAuthorization(options =>
  {
      options.AddPolicy("ADRoleOnly", policy =>
          policy.Requirements.Add(new CheckADGroupRequirement("DOMAIN\\Domain Admin")));
  });
  
  services.AddSingleton<IAuthorizationHandler, CheckADGroupHandler>();

  4.Controller

  [Authorize(Policy = "ADRoleOnly")]
   public class ADController : Controller

  Refer to Configure Active Directory group and Check if user belongs to that AD group in .Net CORE 2.2.

  Xing

  Learning Always
  
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  Shadow_Kitte...

  Member

  19 Points

  45 Posts

  Re: Using AD groups to authorise access to pages using IIS Windows Authentication - ASP.NET Core...

  Feb 08, 2019 01:00 PM|Shadow_Kittencorn|LINK

  Thanks for you help.

  The second version worked :)