问题
I have an application which requires role authorization using custom database. The database is set up with a tblUsers
table that has a reference to a tblRoles
table. The users are also already assigned to their roles.
I also want to use the [Authorize(Role = "RoleName")]
attribute on each action to check if an authenticated user is assigned to "RoleName"
in the database. I'm having a lot of trouble figuring out where I need to make a modification to the [Authorize]
attribute so it behaves that way. I just want to see if a username has a role, I won't have a page to manage roles in the database.
I have tried implementing custom storage providers for ASP.NET Core Identity, but it's starting to look like this is not what I need because I'm not gonna be managing roles within the application, and I can't tell how it affects the behavior of [Authorize]
attribute.
Also, it's likely that I have a false assumption in my understanding on how the [Authorize]
attribute even works. If you notice it, I would appreciate if you could point it out.
回答1:
I had a similar problem when my client asked for granular permissions for each role. I couldn't find a way to modify the Authorize attribute but was able to implement the solution with a custom attribute. But it depends on one thing i.e can you get the userId of the calling user? I used cookie authentication so I just include the userId in my claims when someone logs in so when a request comes I can always get it from there. I think the built-in Session logic in asp.net might get the job done too, I can't say for sure though. Anyways the logic for custom authorization goes like this:
- Load users and roles from database to cache on startup. If you haven't set up a cache in your program (and don't want to) you can simply make your own for this purpose by making a UserRoleCache class with 2 static lists in it. Also there are several ways of loading data from db on startup but I found it easy to do that directly in Program.cs as you'll see below.
- Define your custom attribute to check if the calling user has the required role by iterating over lists in cache and return 403 if not.
Modify your Program class like:
public class Program
{
public static async Task Main(string[] args)
{
IWebHost webHost = CreateWebHostBuilder(args).Build();
using (var scope = webHost.Services.CreateScope())
{
//Get the DbContext instance. Replace MyDbContext with the
//actual name of the context in your program
var context = scope.ServiceProvider.GetRequiredService<MyDbContext>();
List<User> users = await context.User.ToListAsync();
List<Role> roles = await context.Role.ToListAsync();
//You may make getters and setters, this is just to give you an idea
UserRoleCache.users = users;
UserRoleCache.roles = roles;
}
webHost.Run();
}
public static IWebHostBuilder CreateWebHostBuilder(string[] args) =>
WebHost.CreateDefaultBuilder(args)
.UseStartup<Startup>();
}
Then comes the logic for checking if user has a role. Notice I've used an array of roles because sometimes you'll want to allow access to multiple roles.
public class RoleRequirementFilter : IAuthorizationFilter
{
private readonly string[] _roles;
public PermissionRequirementFilter(string[] roles)
{
_roles = roles;
}
public void OnAuthorization(AuthorizationFilterContext context)
{
bool hasRole = false;
//Assuming there's a way you can get the userId
var userId = GetUserId();
User user = UserRoleCache.users.FirstOrDefault(x => x.Id == userId);
//Where roleType is the name of the role like Admin, Manager etc
List<Role> roles = UserRoleCache.roles.FindAll(x => _roles.Contains(x.RoleType))
foreach(var role in roles)
{
if(user.RoleId == role.Id)
{
hasRole = true;
break;
}
}
if (!hasRole)
context.Result = new StatusCodeResult(403);
}
}
Finally make the Role attribute
public class RoleAttribute : TypeFilterAttribute
{
public RoleAttribute(params string[] roles) : base(typeof(RoleRequirementFilter))
{
Arguments = new object[] { roles };
}
}
Now you can use the Role attribute in your controllers:
public class SampleController : ControllerBase
{
[HttpGet]
[Role("Admin", "Manager")]
public async Task<ActionResult> Get()
{
}
[HttpPost]
[Role("Admin")]
public async Task<ActionResult> Post()
{
}
}
来源:https://stackoverflow.com/questions/60289878/how-to-implement-role-authorization-with-custom-database