I have several Silverlight, WP7 and ASP.NET MVC client applications Most allow anonymous access to the application but secure various features based on a user's credentials when logged in. All of the clients use a common back-end service application for data access and business processing which require the user's credentials for authentication and authorization.
We currently use Forms Authentication in all client applications and I'd like to migrate our architecture to use federated identity and a claims-based model. Passive federation is not an option.
I am looking for the following flow:
The user triggers the login dialog, enters their username and
password then clicks "OK".
Behind-the-scenes, the application calls an active STS service in
our existing service application for authentication.
The service is actually a federated STS and passes the call through
to the (active) IP_STS which may or may not be ADFS.
When the IP returns the token to the FP, the FP modifies the token
with additional claims from the server data store before returning
the token to the client application.
The client application maintains the token in memory for
authorization checks (in Thread.CurrentPrincipal, for example).
The client also passes the token when making requests to other
service operations in our service application.
These service operations will use the token to
authenticate/authorize the request.
This is a very different use-case from any of the articles and samples I've been able to locate. Can anyone provide some guidance and/or point me in the right direction?
It is my understanding from Dominic Baier that WIF doesn't currently support the approach we are taking. We've taken his suggestion and created our own custom STS that moderates authentication using the Provider model.
Unfortunately, the farther we got into this, the more we realized that WIF isn't flexible enough to satisfy our needs at this point. We stuck with the custom STS approach but are using our own transport and credentialling rather than the WIF tooling. Hopefully a future release will give us what we want.
Related
I have to design an IAM solution for a NodeJS microservice using Auth0. Objective is to allow third party mobile application users to access this microservice.
I understand OAuth and OpenID connect solution and one simple solution is third party application accesses APIs as a client using client credentials workflow.
Solution I have to design is allowing users to login and authenticate using their Enterprise IdP connected to our Auth0 Server. So that we can implement authorization and access control at user level.
At the same time customer application needs to be kept agnostic of Auth0 service.
What I mean by it is client should not be required to add any logic in their application for accommodating our Auth0 domain like we have in first party React application. user once logged in to customer application should get access to our API also by using SSO capability. I have read some documents about configuring customer IdP with our Auth0 server acting as a SAML SP. Still I could not understand hows of it and will Auth0 create an OAuth access token in this scenario.
I realise this requires an app to intermediate between customer's mobile app and our API service. Still, I am not able to understand data flow and communication between various components.
Also, I am not sure it is a common situation or requirement? If it is is there any technical term for it? This not seem like a standard B2B scenario.
have to design an IAM solution .. , I am not able to understand data flow and communication between various components ..
Before answering, the answer will points the asked specific questions, may not fit al your needs. SO is not really intended for writing tutorials or searching the documentation. Implementing an IdP (effecively a security module), one needs to do his homework and learn the details.
Maybe using an ready / out of box solution could be interesting. Using an open source IAM such as KeyCloak, WSO2IS could be a quick start. Or cloud services such as AWS Cognito, IBM AppId, Azure AD, .. could be a feasible solution too
a client using client credentials workflow .. access toked received by our API should be for user logged in
The client credentials grant is intended to authenticate only applications. That's it.
To authenticate users, other grant type is needed. For the user authentication the most common option is the authorization code or the implicit grant. The implicit grant is has its weaknesses and is being replaced by the code grant with PKCE (just search it).
End requirement is users of 3rd-party application not required to login again while 3rd-party application fetches data from our API .. Configuring their IdP (most probably Active directory) and our Auth0 servers for the same is all I need to understand
I see most common two options in use:
1. federated SSO authentication
This is the most commonly used option. The external (3rd party) IdP is configured as a "trusted" federated IdP. You often see the scenario when you have a service provider allowing to login with other IdP, often social networks (FB, Google, ...)
The login flow is as follows:
The client authorizes with the provider's (yours) IdP (let's call it IdP1).
IdP1 now acts as as Service Provider with IdP2 (IdP of the partner) and asks for the authorization (redirects the user to the IdP2).
User is authenticated and authorized with IdP2. If the user is already authenticated, the IdP2 doesn't need to ask the user's credentials again, this is how SSO works on this level
IdP2 returns to IdP1 (acting as a service provider).
IdP1 reads the user information (using the id_token, userinfo service - assuming using the OAuth2/OIDC protocol all the time there are other protocols too) and builds its own the user-level token. It may or may not create a local user (it is called user provisioning).
IdP1 returns to the client and the client can request a user-level token.
Then the client can call the API services with the token trusted by the API provider.
2. Assertion Framework for OAuth Authorization Grants
This option is built on top of the Assertion Framework for OAuth 2.0 Client Authentication and Authorization Grants, it is an optional extension of the OAuth2 protocol. I call this a token swap service
Basically the token service could validate the access or ID token of a trusted (partner) IdP and issue its own token based on the provided user information.
As you see there are a lot of information and to build a secure solution you ned to make sure that all steps are properly secured (signature, expiration, issuer, validity, audience, subject domain, .. are validated). Disclaimer - as my job we implement IAM/IDM solutions and a lot can get wrong if shortcuts are taken. So you may really consider using an out of box and proven solution.
We are building a web application in microservices architecture.
We have a service that handles the authorization (i.e user's privileges, access credentials, roles etc...) and we are considering how to pass on these credentials in the system.
We have 2 option:
1. Sign those credentials in the gateway (auth and proxy service) using JWT and pass on all the information so every service could verify it (with its public key) and read the user's info.
2. Every service should make a request to the authorization service for querying the user's access on every action.
We are having difficulties on deciding which way is better in terms of high cohesion and loose coupling and of course making it easy for service development.
You have some other options: instead of reinventing the wheel, you can use an OAuth 2.0 identity provider/broker out of the box.
Keycloak is a free open source identity provider and broker that provides all these functionalities.
Auth0 is a managed commercial service that provides all these functionalities too.
And I'm sure there are many other services exist for OAuth 2.0 protocol.
As for your 2 options:
You can extend the JWT with your custom authorisation claims (roles or permissions) and since the JWT will be signed, then it is safe to assume the data is correct by your service. Give that the JWT is a short lived token that need to renew every few minutes.
I'm working on a WCF project that will be our new service layer.
These services will be called by 2 separate clients, the first of which is a WPF application and the other is an ASP.Net web application. The WPF client will be run by internal users and will authenticate with the service via domain authentication and run under the context of that user. The other will be used by external users and needs to authenticate using some separate mechanism then impersonate a "WebUser" account on our domain.
I'm reading a bit about Windows Identity Foundation and it sounds like this might be a good fit. Am I right in thinking I could have 2 token services, one for domain authentication and one for something like ASP.Net membership authentication (Or some similar equivalent) and have each client get it's token from the relevant STS and pass that along to the WCF service?
I'm assuming there is an STS I can use out of the box for domain authentication, but will I have to implement the second one myself to authenticate web users? I can't find a lot of information on this.
Am I thinking along the right lines or should I just be creating duel endpoints for each service each with a different authentication mechanism? Or should I be doing something completely different?
Thanks
The big advantage of using Claims-Based authentication / WIF is that both the task of authenticating the user AND the administration of the user's properties are moved way from the applications to the STS/Identity provider.
You are developing a service layer but the true benefits of using WIF will be for the applications written on top of your layer. The WPF application will no longer need to connect to the AD and fetch the user's groups to figure out what they are allowed to do. The groups will already be visible as claims in the token the user/WIF provides.
The web application (is it just one web application or more?) will no longer need the ASP.Net Membership database with accompanying user administration. This functionality gets moved to the STS.
There is a cost. (There always is, somehow...) Claims-Based authentication has a rather steep learning curve. It takes a while for the quarter to drop for all people involved.
So the answer to your question depends on what kind of users the web application(s?) built upon your service layer have and how many. And how much they wish to know about them. Can you perhaps trust Google / Facebook / Windows Live for authentication? Are the users already in an existing database within your domain? How much work will it take to maintain the user directories? Do your marketing people wish to send them emails regularly? Et cetera.
This is probably not just for the service layer's developers to decide, but something to discuss with people in the rest of your organisation.
If the benefits are not particularly big, the alternative is to simply keep these responsibilities at the web application's server. Each web application will have a good old ASP.Net membership database, it'll authenticate the user all by itself. When asking queries from the service layer, it'll present its web server certificate plus specify the user's name and type.
If the benefits are big enough, you can in principle use ADFS 2.0 for everything. It can also store external users nowadays and it's free if you already have Active Directory. Or the ThinkTecture 2.0 server that Ross recommends. It's easier to customize and perhaps your systems administrators and security folks will not be too enthusiastic about opening the firewall to the ADFS server.
Microsoft has some good reads on WIF, in particular an Overview of Claims-Based Architecture.
You should take a look at identity server as it can indeed handle this scenario.
The person who leads the project above has a great pluralsight video on this exact scenario! You need to sign up to watch it, but they offer a free trial.
Basically you get a token from the identity provider (windows ADFS for the internal client, and what ever you decide for the external users). You will give this token to the federated gateway (identity server probably, but it could be Azure ACS). This will return an authentication token that you can then use with your service.
I'm trying to investigate possibility of using claims aware security in the system I'm developing. The more I read about all this stuff the more confused i get.
So i decided to describe what I know already and I would ask that You correct my statements. I got lost with all those protocols and technologies used.
Below is a simple diagram of my system. There are two services - a REST service implemented using WCF and an ASP MVC web application.
I know I need to get an STS which will be a trusted identity issuer for both of my services. I'll be using roles to differentiate certain levels of access.
The STS functionality might be accomplished by using ADFS (or is there anything more needed in addition to it) or WSO2 Identity Server.
By saying STS I mean a service which will get credentials from a client wanting to authenticate and will return a set of claims (which will beside other information contain the role assigned to the user). This set of claims will be in the form of a token.
On the diagram I marked different client types with different colors. No I'll try to describe what protocols/formats i think will be used. I am pretty confused on what is a format and what is a protocol. But let me try:
Red scenario: rich WCF client authenticates agains REST service
Request to STS will be sent using WS-trust (is there any other possibility in ADFS or WSO2?). The credentials might be in one of several forms such as X.509 certificate, password digest, kerberos, windows authentication, SAML token (this is used in federation scenarios, right?), and few other.
The answer to the client will be in a form of SWT token sent over OAuth protocol since this is the way we do it when trying to authenticate against REST services.
Does ADFS support SWT and OAuth? I couldn't find the information.
The client then send the token received from STS to the REST service. Once again this is SWT token on OAuth.
I guess as for the client code all can be easily implemented using Windows Identity Framework.
Green scenario: rich android client authenticates against REST service
All protocols/formats are the same as in previous scenario. Is there any framework which can let me easily implement this?
Blue scenario: user of web browser authenticates against ASP MVC web application
User goes to the web app's main page. The webapp detects that he isn't authenticated yet so redirects him to the sign on page on STS (the sign on page is on STS, right?).
and 3. STS authenticates the user and sends HTTP response containing SAML token and redirection to webapp. So here is HTTP used, not WS-Trusts.
Another question. In this web browser scenario there will be a cookie written on a client's machine. So whenever client will try to authenticate once again, he'll just send the cookie to sts to obtain the token. There will be no need to send the credentials. STS will issue a token basing on the cookie without any real authentication logic involved. Is that statement correct?
ADFS / WIF out the box only supports SAML tokens - no OAuth support.
ADFS / WCF uses WS-Trust.
The sign-on page is part of ADFS.
The answer is "Yes" to your last question but (at some point) it will expire and the user will have to authenticate again.
Update:
Have a look at Claims Based Identity & Access Control Guide
I am working with WCF Webhttp services. I have created a bunch of services and all that remains is to put in user authentication...
Questions
Keeping with the rest architecture style, should I authenticate each service call against the user db.
If so, I should just do authentication by supplying the credentials and password each time the service is called and make it secure with SSL. Basically, each webget/webinvoke function should contain the user credentials as parameters and I authenticate each call. Is this right? This seems rather inefficient.
Using session key somehow seems wrong but any pointers as to how to use Session in WCF Webhttp?
I am not working with ASP .net membership (will be looking into it soon) since I was working with Mysql and have my own registration/user database created. Should I be looking at that? Can I use a wcf authentication service along with wcf webhttp services?
Any literature on handling authentication in WCF webhttp services would be greatly helpful.
Many thanks
You can check Chapter 8 of RESTful .NET book (Amazon, Google books)
You will authenticate only the first call from the user, any subsequent calls will use the context of the authenticated user. There are several options how you can use SSL(TLS), like always or just when you send username/password.
I am not sure where exactly and how you store the authentication token (like in Session or similar type).
You don't need to use ASP.NET membership provider, in fact you may not use any membership provider at all, just use other authentication models. Usually, there will be only one authentication model per service, like you get the credentials, check them against persisted storage, if valid you set the security token and that token is used for all the next calls for a limited amount of time.