I have custom implementation of AuthenticationTokenProvider abstraction. It has two methods to be overriden that I'm using: CreateAsync, ReceiveAsync.
In OAuthAuthorizationServerOptions I have RefreshTokenProvider set to my custom AuthenticationTokenProvider implementation.
My access tokens expire in 20 minutes. My refresh tokens expire in 24 hours. When access token expires a request comes with grant_type=refresh_token containing refresh token. I observe ReceiveAsync is called. There is a logic of setting Ticket property of AuthenticationTokenReceiveContext. But afterwards CreateAsync method is called, where there is a logic of setting token in AuthenticationTokenCreateContext. The Ticket property of AuthenticationTokenCreateContext does not seem to be that one I have set previously in ReceiveAsync method.
As a result I receive response with new access token and refresh token. I don't want refresh token to be reissued each time I want to exchange my access token, I already have one valid for 24 hours.
Eventually I have found how to answer my question. I can leverage OwinContext.Environment to store a flag which tells that my refresh token is not expired yet so there is no need of creation a new one.
public class RefreshTokenProvider : AuthenticationTokenProvider
{
private const string IsRefreshTokenExpiredName = "IsRefreshTokenExpired";
#region ctor
public RefreshTokenProvider()
{
}
#endregion
public async override Task CreateAsync(AuthenticationTokenCreateContext context)
{
if (!context.OwinContext.Environment.ContainsKey(IsRefreshTokenExpiredName) || (bool)context.OwinContext.Environment[IsRefreshTokenExpiredName])
{
var hours = int.Parse(ConfigurationManager.AppSettings["RefreshTokenExpirationHours"]);
var now = DateTime.UtcNow;
context.Ticket.Properties.IssuedUtc = now;
context.Ticket.Properties.ExpiresUtc = now.AddHours(hours);
context.SetToken(context.SerializeTicket());
}
}
public async override Task ReceiveAsync(AuthenticationTokenReceiveContext context)
{
context.OwinContext.Response.Headers.Add("Access-Control-Allow-Origin", new[] { ConfigurationManager.AppSettings["CorsOrigins"] });
context.OwinContext.Response.Headers.Add("Access-Control-Allow-Method", new[] { "POST" });
context.DeserializeTicket(context.Token);
if (context.Ticket.Properties.ExpiresUtc > DateTime.UtcNow)
context.OwinContext.Environment[IsRefreshTokenExpiredName] = false;
}
}
Related
In our ASP .NET Core 2.0, Web API, when the user logs in, we generate a GUID and return that to the user after storing it in database. What is the best practice to validate this token when the user submits a request to a controller having Authorize attribute on it.
Should I override AuthorizeAttribute.OnAuthorization and put my custom logic in there ? or is there any other place where I should place my custom logic ?
Thanks in advance.
In ASP .NET Core 2.0 you can write you own Middleware to validate token. You can see this video as exapmle - https://www.youtube.com/watch?v=n0llyujNGw8.
Summarily:
1. Create TokenMiddleware:
public class TokenMiddleware
{
// always should be RequestDelegate in constructor
private readonly RequestDelegate _next;
public TokenMiddleware(RequestDelegate next)
{
_next = next;
}
// always should be defiened Invoke or InvokeAsync with HttpContext and returned Task (You can also inject you services here - for example DataContext)
public async Task InvokeAsync(HttpContext context, DataContext dataContext)
{
var validKey = true;
// than you logic to validate token
if (!validKey)
{
context.Response.StatusCode = (int) HttpStatusCode.Forbidden;
await context.Response.WriteAsync("Invalid Token");
}
// if validm than next middleware Invoke
else
{
await _next.Invoke(context);
}
}
}
// Extension to IApplicationBuilder (to register you Middleware)
public static class TokenExtensions
{
public static IApplicationBuilder UseTokenAuth(this IApplicationBuilder builder)
{
return builder.UseMiddleware<TokenMiddleware>();
}
}
Registred you Middleware in Startup:
app.UseTokenAuth();
Question was made long time ago, but for people that might stumble upon it, here is the way I did it, taking advantage of authentication and authorization middlewares. The question doesn't have details about the way the token is passed in the request but I am assuming a standard Authorization header.
Create a custom AuthenticationHandler
MyCustomTokenHandler.cs
public class MyCustomTokenHandler: AuthenticationHandler<AuthenticationSchemeOptions>
{
public MyCustomTokenHandler(IOptionsMonitor<AuthenticationSchemeOptions> options, ILoggerFactory logger, UrlEncoder encoder, ISystemClock clock) : base(options, logger, encoder, clock)
{
}
protected override async Task<AuthenticateResult> HandleAuthenticateAsync()
{
if (!Request.Headers.ContainsKey("Authorization"))
{
return AuthenticateResult.NoResult();
}
if (!AuthenticationHeaderValue.TryParse(Request.Headers["Authorization"], out AuthenticationHeaderValue? headerValue))
{
return AuthenticateResult.NoResult();
}
if (!Scheme.Name.Equals(headerValue.Scheme, StringComparison.OrdinalIgnoreCase))
{
return AuthenticateResult.NoResult();
}
if (headerValue.Parameter == null)
{
return AuthenticateResult.NoResult();
}
//The token value is in headerValue.Parameter, call your db to verify it and get the user's data
var claims = new[] { new Claim(ClaimTypes.Name, "username found in db") };
//set more claims if you want
var identity = new ClaimsIdentity(claims, Scheme.Name);
var principal = new ClaimsPrincipal(identity);
var ticket = new AuthenticationTicket(principal, Scheme.Name);
return AuthenticateResult.Success(ticket);
}
}
Register the handler and enable authorization
Program.cs
builder.Services.AddAuthentication("Bearer").AddScheme<AuthenticationSchemeOptions, MyCustomTokenHandler>("Bearer", null);
//...
var app = builder. Build();
app.UseAuthentication();
app.UseAuthorization();
Most of the code is inspired by this blog post: https://joonasw.net/view/creating-auth-scheme-in-aspnet-core-2
I have implemented a custom OAuthAuthorizationServerProvider to add a domain constraint for the account login. Everything was good. However, I met a problem that, once the user get the token, they can use it for whatever system they want. For example:
They request the TokenEndpointPath with proper username and password (assume it is the admin account of Tenant 1): http://localhost:40721/api/v1/account/auth and receive the Bearer Token.
Now they use it to access: http://localhost:40720/api/v1/info/admin, which is of Tenant 0. The request is considered Authorized.
I tried changing the CreateProperties method but it did not help:
public static AuthenticationProperties CreateProperties(string userName)
{
var tenant = DependencyUtils.Resolve<IdentityTenant>();
IDictionary<string, string> data = new Dictionary<string, string>
{
{ "userName", userName },
{ "tenantId", tenant.Tenant.Id.ToString() },
};
return new AuthenticationProperties(data);
}
I also tried overriding ValidateAuthorizeRequest, but it is never called in my debug.
Do I need to implement a check anywhere else, so the Token is only valid for a domain/correct tenant?
(NOTE: a tenant may have multiple domains, so it's great if I can manually perform an account check against correct tenant rather than sticking to a domain. However, it's a plus if I could do that, or else, simply limit the token to the domain is ok)
Not a direct answer to my question (since it's not inside ASP.NET Identity workflow), but the simplest fix I applied was to use ActionFilterAttribute instead.
public class DomainValidationFilter : ActionFilterAttribute
{
public override Task OnActionExecutingAsync(HttpActionContext actionContext, CancellationToken cancellationToken)
{
// Other Code...
// Validate if the logged in user is from correct tenant
var principal = actionContext.ControllerContext.RequestContext.Principal;
if (principal != null && principal.Identity != null && principal.Identity.IsAuthenticated)
{
var userId = int.Parse(principal.Identity.GetUserId());
// Validate against the tenant Id of your own storage, and use this code to invalidate the request if it is trying to exploit:
actionContext.Response = actionContext.Request.CreateResponse(System.Net.HttpStatusCode.Unauthorized, "Invalid Token");
}
return base.OnActionExecutingAsync(actionContext, cancellationToken);
}
}
Then applies the Filter to all actions by registering it in either FilterConfig or WebApiConfig:
config.Filters.Add(new DomainValidationFilter());
I'm trying to implement a simple OAuthAuthorizationServerProvider in ASP.NET WebAPI 2. My main purpose is to learn how to have a token for a mobile app. I would like users to login with username & password, and then receive a token (and a refresh token so they won't have to re-enter credentials once token expires). Later on, I would like to have the chance to open the API for external use by other applications (like one uses Facebook api and such...).
Here is how I've set-up my AuthorizationServer:
app.UseOAuthAuthorizationServer(new OAuthAuthorizationServerOptions()
{
AllowInsecureHttp = true,
TokenEndpointPath = new PathString("/token"),
AccessTokenExpireTimeSpan = TimeSpan.FromMinutes(5),
Provider = new SimpleAuthorizationServerProvider(new SimpleAuthorizationServerProviderOptions()
{
ValidateUserCredentialsFunction = ValidateUser
}),
RefreshTokenProvider = new SimpleRefreshTokenProvider()
});
This is my SimpleAuthorizationServerProviderOptions implementation:
public class SimpleAuthorizationServerProvider : OAuthAuthorizationServerProvider
{
public delegate Task<bool> ClientCredentialsValidationFunction(string clientid, string secret);
public delegate Task<IEnumerable<Claim>> UserCredentialValidationFunction(string username, string password);
public SimpleAuthorizationServerProviderOptions Options { get; private set; }
public SimpleAuthorizationServerProvider(SimpleAuthorizationServerProviderOptions options)
{
if (options.ValidateUserCredentialsFunction == null)
{
throw new NullReferenceException("ValidateUserCredentialsFunction cannot be null");
}
Options = options;
}
public SimpleAuthorizationServerProvider(UserCredentialValidationFunction userCredentialValidationFunction)
{
Options = new SimpleAuthorizationServerProviderOptions()
{
ValidateUserCredentialsFunction = userCredentialValidationFunction
};
}
public SimpleAuthorizationServerProvider(UserCredentialValidationFunction userCredentialValidationFunction, ClientCredentialsValidationFunction clientCredentialsValidationFunction)
{
Options = new SimpleAuthorizationServerProviderOptions()
{
ValidateUserCredentialsFunction = userCredentialValidationFunction,
ValidateClientCredentialsFunction = clientCredentialsValidationFunction
};
}
public override async Task ValidateClientAuthentication(OAuthValidateClientAuthenticationContext context)
{
if (Options.ValidateClientCredentialsFunction != null)
{
string clientId, clientSecret;
if (!context.TryGetBasicCredentials(out clientId, out clientSecret))
{
context.TryGetFormCredentials(out clientId, out clientSecret);
}
var clientValidated = await Options.ValidateClientCredentialsFunction(clientId, clientSecret);
if (!clientValidated)
{
context.Rejected();
return;
}
}
context.Validated();
}
public override async Task GrantResourceOwnerCredentials(OAuthGrantResourceOwnerCredentialsContext context)
{
if (Options.ValidateUserCredentialsFunction == null)
{
throw new NullReferenceException("ValidateUserCredentialsFunction cannot be null");
}
var claims = await Options.ValidateUserCredentialsFunction(context.UserName, context.Password);
if (claims == null)
{
context.Rejected();
return;
}
// create identity
var identity = new ClaimsIdentity(claims, context.Options.AuthenticationType);
// create metadata to pass to refresh token provider
var props = new AuthenticationProperties(new Dictionary<string, string>()
{
{ "as:client_id", context.UserName }
});
var ticket = new AuthenticationTicket(identity, props);
context.Validated(ticket);
}
public override async Task GrantRefreshToken(OAuthGrantRefreshTokenContext context)
{
var originalClient = context.Ticket.Properties.Dictionary["as:client_id"];
var currentClient = context.ClientId;
// enforce client binding of refresh token
if (originalClient != currentClient)
{
context.Rejected();
return;
}
// chance to change authentication ticket for refresh token requests
var newIdentity = new ClaimsIdentity(context.Ticket.Identity);
newIdentity.AddClaim(new Claim("newClaim", "refreshToken"));
var newTicket = new AuthenticationTicket(newIdentity, context.Ticket.Properties);
context.Validated(newTicket);
}
}
And my SimpleRefreshTokenProvider implementation:
public class SimpleRefreshTokenProvider : IAuthenticationTokenProvider
{
private static ConcurrentDictionary<string, AuthenticationTicket> _refreshTokens =
new ConcurrentDictionary<string, AuthenticationTicket>();
public void Create(AuthenticationTokenCreateContext context)
{
}
public async Task CreateAsync(AuthenticationTokenCreateContext context)
{
var guid = Guid.NewGuid().ToString();
var refreshTokenProperties = new AuthenticationProperties(context.Ticket.Properties.Dictionary)
{
IssuedUtc = context.Ticket.Properties.IssuedUtc,
ExpiresUtc = DateTime.UtcNow.AddYears(1)
};
var refreshTokenTicket = new AuthenticationTicket(context.Ticket.Identity, refreshTokenProperties);
_refreshTokens.TryAdd(guid, refreshTokenTicket);
context.SetToken(guid);
}
public void Receive(AuthenticationTokenReceiveContext context)
{
}
public async Task ReceiveAsync(AuthenticationTokenReceiveContext context)
{
AuthenticationTicket ticket;
if (_refreshTokens.TryRemove(context.Token, out ticket))
{
context.SetTicket(ticket);
}
}
}
What I don't fully understand is the use of ClientId and Secret vs Username and Password. The code I pasted generates a token by username and password and I can work with that token (until it expires), but when I try to get a refresh token, I must have the ClientId.
Also, if a token expires, the correct way is to send the refresh token and get a new token? What if the refresh token gets stolen? isn't it the same as a username & password getting stolen?
What I don't fully understand is the use of ClientId and Secret vs Username and Password. The code I pasted generates a token by username and password and I can work with that token (until it expires), but when I try to get a refresh token, I must have the ClientId.
Also, if a token expires, the correct way is to send the refresh token and get a new token? What if the refresh token gets stolen? isn't it the same as a username & password getting stolen?
In OAuth2 is essential to authenticate both the user and the client in any authorization flow defined by the protocol. The client authentication (as you may guess) enforces the use of your API only by known clients. The serialized access token, once generated, is not bound to a specific client directly. Please note that the ClientSecret must be treated as a confidential information, and can be used only by clients that can store this information in some secure way (e.g. external services clients, but not javascript clients).
The refresh token is simply an alternative "grant type" for OAuth2, and, as you stated correctly, will substitute the username and password pair for a User. This token must be treated as confidential data (even more confidential than the access token), but gives advantages over storing the username & password on the client:
it can be revoked by the user if compromised;
it has a limited lifetime (usually days or weeks);
it does not expose user credentials (an attacker can only get access tokens for the "scope" the refresh token was issued).
I suggest you to read more about the different grant types defined in OAuth 2 checking in the official draft. I also recommend you this resource I found very useful when firstly implemented OAuth2 in Web API myself.
Sample requests
Here are two request examples using fiddler, for Resource Owner Password Credentials Grant:
and for Refresh Token Grant:
I have a MVC Web Api project and am logging all requests and responses using a MessageHandler. When an api request comes in, the bearer token in the header lets Asp.Net do its thing and authenticates that user. The message handler therefore knows who the user is and we write that to a log file.
Now, to speed up things I'm caching with Cachecow. So I've added the cachecow handler after the MessageHandler and when a second request comes in, from a caching point of view everything works fine. The controller code is never hit and the response is returned from the cache.
However, the MessageHandler does not have a value for the User.Identity so I cannot tell who made the request.
I need to log all requests and identify who made them even when the code in the controllers is not hit.
I think one workaround is to force the api requests to pass the bearer token and user id in the header. That way I can check the user id claim and use that to log who made the request.
protected override async Task OutgoingMessageAsync(string correlationId, string requestInfo, byte[] message, string responseTimeMilliseconds)
{
await Task.Run(() =>
Debug.WriteLine(string.Format("{0} - Response: {1}\r\n{2}", correlationId, requestInfo, Encoding.UTF8.GetString(message))));
);
}
User identity is null when getting response from cache.
?HttpContext.Current.User.Identity
{System.Security.Claims.ClaimsIdentity}
[System.Security.Claims.ClaimsIdentity]: {System.Security.Claims.ClaimsIdentity}
AuthenticationType: null
IsAuthenticated: false
Name: null
Any ideas?
In authentication process, set object:
System.Threading.Thread.CurrentPrincipal = YourUserInformationObject;
This object need implement "System.Security.Principal.IPrincipal" Example
public class YourUserInformation : IPrincipal
{
public Int32 Id { get; set; }
public String NameUser { get; set; }
public IIdentity Identity { get; private set; }
public YourUserInformation()
{
this.Identity = new GenericIdentity(NameUser ?? "");
}
public bool IsInRole(string role) { return false; }
}
In authentication process you save object in System.Threading.Thread.CurrentPrincipal
public void Authentication(AuthorizationContext filterContext)
{
YourUserInformation user = YourMethodGetUserLogin();
System.Threading.Thread.CurrentPrincipal = user ;
}
Well you should create HttpContext from Request and there you will be able to use User.Identity object:
protected override async Task<HttpResponseMessage> SendAsync(HttpRequestMessage request, CancellationToken cancellationToken)
{
var context = ((HttpContextBase)request.Properties["MS_HttpContext"]);
var uname = username = context.User.Identity.Name;
var response = await base.SendAsync(request, cancellationToken);
return response;
}
Also check this article: http://arcware.net/logging-web-api-requests/
Hoope this help!
try get in
System.Threading.Thread.CurrentPrincipal
I use OWIN Oauth in my ASP.NET MVC application to provide access token for mobile applications. Here's the setup of OAuth:
app.UseOAuthAuthorizationServer(new OAuthAuthorizationServerOptions
{
TokenEndpointPath = new PathString("/api/authenticate/login"),
Provider = dependencyContainer.GetService<IOAuthAuthorizationServerProvider>(),
RefreshTokenProvider = dependencyContainer.GetService<IAuthenticationTokenProvider>(),
AccessTokenExpireTimeSpan = TimeSpan.FromMinutes(applicationSettings.AccessTokenLifeTimeInMinutes),
AllowInsecureHttp = true
});
app.UseOAuthBearerAuthentication(new OAuthBearerAuthenticationOptions());
I also have custom provider and custom refresh token provider as you can see above. Everything is working fine, when a request from mobile is expired or invalid, I use a custom AuthorizeAttribute to return a json with message "unauthorized"
public class ApiAuthorizeAttribute : AuthorizeAttribute
{
protected override void HandleUnauthorizedRequest(AuthorizationContext filterContext)
{
filterContext.Result = new JsonResult
{
Data = new
{
success = false,
error = "Unauthorized"
},
JsonRequestBehavior = JsonRequestBehavior.AllowGet
};
}
}
However in one scenario, the mobile applications need to differentiate the response from server for 2 cases: access token is expired, or access token is invalid (.e.g. modified in the middle). I'm not sure how I can implement that requirement. I tried to create a custom access token provider, inheriting from AuthenticationTokenProvider, register it in UseOAuthAuthorizationServer() above, but both Receive() and ReceiveAsync() are not called when server receives access token from mobile
Solved the issue. My approach of creating custom access token provider works. Initially I registered it with UseOAuthAuthorizationServer(), but it should be registered using UseOAuthBearerAuthentication() instead
Here's my custom class, in case anyone needs:
public class CustomAccessTokenProvider : AuthenticationTokenProvider
{
public override void Receive(AuthenticationTokenReceiveContext context)
{
context.DeserializeTicket(context.Token);
var expired = context.Ticket.Properties.ExpiresUtc < DateTime.UtcNow;
if (expired)
{
//If current token is expired, set a custom response header
context.Response.Headers.Add("X-AccessTokenExpired", new string[] { "1" });
}
base.Receive(context);
}
}
Register it when setting up OWIN OAuth:
app.UseOAuthBearerAuthentication(new OAuthBearerAuthenticationOptions
{
AccessTokenProvider = new CustomAccessTokenProvider()
});