asp.net-mvc – ASP.NET MVC自定义授权

AuthorizationContext(OnAuthorize的参数)提供对Controller，RouteData，HttpContext等的访问。你应该能够在自定义的授权过滤器中使用这些来做你想要的。下面是来自AuthorizeAttribute的RoleOrOwnerAttribute的代码示例。

public override void OnAuthorization( AuthorizationContext filterContext )
{
    if (filterContext == null)
    {
        throw new ArgumentNullException( "filterContext" );
    }

    if (AuthorizeCore( filterContext.HttpContext )) // checks roles/users
    {
        SetCachePolicy( filterContext );
    }
    else if (!filterContext.HttpContext.User.Identity.IsAuthenticated)
    {
        // auth failed,redirect to login page
        filterContext.Result = new HttpUnauthorizedResult();
    }
    // custom check for global role or ownership
    else if (filterContext.HttpContext.User.IsInRole( "SuperUser" ) || IsOwner( filterContext ))
    {
        SetCachePolicy( filterContext );
    }
    else
    {
        ViewDataDictionary viewData = new ViewDataDictionary();
        viewData.Add( "Message","You do not have sufficient privileges for this operation." );
        filterContext.Result = new ViewResult { MasterName = this.MasterName,ViewName = this.ViewName,ViewData = viewData };
    }

}

// helper method to determine ownership,uses factory to get data context,// then check the specified route parameter (property on the attribute)
// corresponds to the id of the current user in the database.
private bool IsOwner( AuthorizationContext filterContext )
{
    using (IAuditableDataContextWrapper dc = this.ContextFactory.GetDataContextWrapper())
    {
        int id = -1;
        if (filterContext.RouteData.Values.ContainsKey( this.RouteParameter ))
        {
            id = Convert.ToInt32( filterContext.RouteData.Values[this.RouteParameter] );
        }

        string userName = filterContext.HttpContext.User.Identity.Name;

        return dc.Table<Participant>().Where( p => p.UserName == userName && p.ParticipantID == id ).Any();
    }
}


protected void SetCachePolicy( AuthorizationContext filterContext )
{
    // ** IMPORTANT **
    // Since we're performing authorization at the action level,the authorization code runs
    // after the output caching module. In the worst case this could allow an authorized user
    // to cause the page to be cached,then an unauthorized user would later be served the
    // cached page. We work around this by telling proxies not to cache the sensitive page,// then we hook our custom authorization code into the caching mechanism so that we have
    // the final say on whether a page should be served from the cache.
    HttpCachePolicyBase cachePolicy = filterContext.HttpContext.Response.Cache;
    cachePolicy.SetProxyMaxAge( new TimeSpan( 0 ) );
    cachePolicy.AddValidationCallback( CacheValidateHandler,null /* data */);
}