abp-authorization

---
name: abp-authorization
description: ABP permission system - PermissionDefinitionProvider, [Authorize] attribute, CheckPolicyAsync, IsGrantedAsync, ICurrentUser, IPermissionManager, multi-tenancy side. Use when working with permissions, authorization, role-based access, or security in ABP projects.
---

# ABP Authorization

> **Docs**: https://abp.io/docs/latest/framework/fundamentals/authorization

## Permission Definition
Define permissions in `*.Application.Contracts` project:

```csharp
public static class BookStorePermissions
{
    public const string GroupName = "BookStore";

    public static class Books
    {
        public const string Default = GroupName + ".Books";
        public const string Create = Default + ".Create";
        public const string Edit = Default + ".Edit";
        public const string Delete = Default + ".Delete";
    }
}
```

Register in provider:
```csharp
public class BookStorePermissionDefinitionProvider : PermissionDefinitionProvider
{
    public override void Define(IPermissionDefinitionContext context)
    {
        var bookStoreGroup = context.AddGroup(BookStorePermissions.GroupName, L("Permission:BookStore"));

        var booksPermission = bookStoreGroup.AddPermission(
            BookStorePermissions.Books.Default,
            L("Permission:Books"));

        booksPermission.AddChild(
            BookStorePermissions.Books.Create,
            L("Permission:Books.Create"));

        booksPermission.AddChild(
            BookStorePermissions.Books.Edit,
            L("Permission:Books.Edit"));

        booksPermission.AddChild(
            BookStorePermissions.Books.Delete,
            L("Permission:Books.Delete"));
    }

    private static LocalizableString L(string name)
    {
        return LocalizableString.Create<BookStoreResource>(name);
    }
}
```

## Using Permissions

### Declarative (Attribute)
```csharp
[Authorize(BookStorePermissions.Books.Create)]
public virtual async Task<BookDto> CreateAsync(CreateBookDto input)
{
    // Only users with Books.Create permission can execute
}
```

### Programmatic Check
```csharp
public class BookAppService : ApplicationService
{
    public async Task DoSomethingAsync()
    {
        // Check and throw if not granted
        await CheckPolicyAsync(BookStorePermissions.Books.Edit);

        // Or check without throwing
        if (await IsGrantedAsync(BookStorePermissions.Books.Delete))
        {
            // Has permission
        }
    }
}
```

### Allow Anonymous Access
```csharp
[AllowAnonymous]
public virtual async Task<BookDto> GetPublicBookAsync(Guid id)
{
    // No authentication required
}
```

## Current User
Access authenticated user info via `CurrentUser` property (available in base classes like `ApplicationService`, `DomainService`, `AbpController`):

```csharp
public class BookAppService : ApplicationService
{
    public async Task DoSomethingAsync()
    {
        // CurrentUser is available from base class - no injection needed
        var userId = CurrentUser.Id;
        var userName = CurrentUser.UserName;
        var email = CurrentUser.Email;
        var isAuthenticated = CurrentUser.IsAuthenticated;
        var roles = CurrentUser.Roles;
        var tenantId = CurrentUser.TenantId;
    }
}

// In other services, inject ICurrentUser
public class MyService : ITransientDependency
{
    private readonly ICurrentUser _currentUser;
    public MyService(ICurrentUser currentUser) => _currentUser = currentUser;
}
```

### Ownership Validation
```csharp
public async Task UpdateMyBookAsync(Guid bookId, UpdateBookDto input)
{
    var book = await _bookRepository.GetAsync(bookId);

    if (book.CreatorId != CurrentUser.Id)
    {
        throw new AbpAuthorizationException();
    }

    // Update book...
}
```

## Multi-Tenancy Permissions
Control permission availability per tenant side:

```csharp
bookStoreGroup.AddPermission(
    BookStorePermissions.Books.Default,
    L("Permission:Books"),
    multiTenancySide: MultiTenancySides.Tenant // Only for tenants
);
```

Options: `MultiTenancySides.Host`, `Tenant`, or `Both`

## Feature-Dependent Permissions
```csharp
booksPermission.RequireFeatures("BookStore.PremiumFeature");
```

## Permission Management
Grant/revoke permissions programmatically:

```csharp
public class MyService : ITransientDependency
{
    private readonly IPermissionManager _permissionManager;

    public async Task GrantPermissionToUserAsync(Guid userId, string permissionName)
    {
        await _permissionManager.SetForUserAsync(userId, permissionName, true);
    }

    public async Task GrantPermissionToRoleAsync(string roleName, string permissionName)
    {
        await _permissionManager.SetForRoleAsync(roleName, permissionName, true);
    }
}
```

## Security Best Practices
- Never trust client input for user identity
- Use `CurrentUser` property (from base class) or inject `ICurrentUser`
- Validate ownership in application service methods
- Filter queries by current user when appropriate
- Don't expose sensitive fields in DTOs