/* ****************************************************************************
*
* Copyright (c) Microsoft Corporation. All rights reserved.
*
* This software is subject to the Microsoft Public License (Ms-PL).
* A copy of the license can be found in the license.htm file included
* in this distribution.
*
* You must not remove this notice, or any other, from this software.
*
* ***************************************************************************/
namespace System.Web.Mvc{
using System;
using System.Diagnostics.CodeAnalysis;
using System.Linq;
using System.Security.Principal;
using System.Web;
[SuppressMessage("Microsoft.Performance", "CA1813:AvoidUnsealedAttributes",
Justification = "Unsealed so that subclassed types can set properties in the default constructor or override our behavior.")]
[AttributeUsage(AttributeTargets.Class | AttributeTargets.Method, Inherited = true, AllowMultiple = true)]
public class AuthorizeAttribute : FilterAttribute, IAuthorizationFilter {
private readonly object _typeId = new object();
private string _roles;
private string[] _rolesSplit = new string[0];
private string _users;
private string[] _usersSplit = new string[0];
public string Roles {
get {
return _roles ?? String.Empty;
}
set {
_roles = value;
_rolesSplit = SplitString(value);
}
}
public override object TypeId {
get {
return _typeId;
}
}
public string Users {
get {
return _users ?? String.Empty;
}
set {
_users = value;
_usersSplit = SplitString(value);
}
}
// This method must be thread-safe since it is called by the thread-safe OnCacheAuthorization() method.
protected virtual bool AuthorizeCore(HttpContextBase httpContext) {
if (httpContext == null) {
throw new ArgumentNullException("httpContext");
}
IPrincipal user = httpContext.User;
if (!user.Identity.IsAuthenticated) {
return false;
}
if (_usersSplit.Length > 0 && !_usersSplit.Contains(user.Identity.Name, StringComparer.OrdinalIgnoreCase)) {
return false;
}
if (_rolesSplit.Length > 0 && !_rolesSplit.Any(user.IsInRole)) {
return false;
}
return true;
}
private void CacheValidateHandler(HttpContext context, object data, ref HttpValidationStatus validationStatus) {
validationStatus = OnCacheAuthorization(new HttpContextWrapper(context));
}
public virtual void OnAuthorization(AuthorizationContext filterContext) {
if (filterContext == null) {
throw new ArgumentNullException("filterContext");
}
if (AuthorizeCore(filterContext.HttpContext)) {
// ** 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 */);
}
else {
HandleUnauthorizedRequest(filterContext);
}
}
protected virtual void HandleUnauthorizedRequest(AuthorizationContext filterContext) {
// Returns HTTP 401 - see comment in HttpUnauthorizedResult.cs.
filterContext.Result = new HttpUnauthorizedResult();
}
// This method must be thread-safe since it is called by the caching module.
protected virtual HttpValidationStatus OnCacheAuthorization(HttpContextBase httpContext) {
if (httpContext == null) {
throw new ArgumentNullException("httpContext");
}
bool isAuthorized = AuthorizeCore(httpContext);
return (isAuthorized) ? HttpValidationStatus.Valid : HttpValidationStatus.IgnoreThisRequest;
}
internal static string[] SplitString(string original) {
if (String.IsNullOrEmpty(original)) {
return new string[0];
}
var split = from piece in original.Split(',')
let trimmed = piece.Trim()
where !String.IsNullOrEmpty(trimmed)
select trimmed;
return split.ToArray();
}
}
}
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