OAuth2 authorization interface using KeyCloak - oauth-2.0

I'm trying to use KeyCloak as identity provider service for 3rd party applications support. The idea is to register the client application in KeyCloak, trusted clients will not require this authorization approval, but there should be "untrusted" client flow, e.g. display user authorization interface as specified in OAuth 2.0 specification.
From what I see in the docs, they have pretty good fine-grained authorization mechanisms which can be used for that on the backend. However I don't see any way to provide authorization screen for /authorize endpoint as shown above.
Maybe this can be custom created SPI or something else which can be used for implementing this to move further. Any ideas of how this can be implemented in KeyCloak? Are there any built-in features which can be reused or custom way implementation?

In Keycloak you can turn on the Consent Required switch per client (see client settings in admin console).
After successful authentication this will bring up a confirmation page similar to your example.

Related

Is it okay to use client credentials grant type for authentication of a WEB API going to be consumed by SailPoint(IAM)

I have an old windows application written in VB.NET with SQL server backend. Currently the new user additions, deletion, adding entitlements etc. are managed by an old approval workflow system. After getting approvals, the user details and entitlements are inserted in to the SQL server database table manually.
I am trying to integrate this application with the SailPoint's Identity and access management. So the new user addition, deletion update and adding entitlements etc will be done through Sailpoint. For this, I would require to create a WEB API which can be called by Sailpoint and expose the functionalities(add user/delete user/add entitlements). The only consumer to this API is SailPoint.
I am new to OAuth and below are the grant types that I came across. But not sure which one I should be using in this particular scenario.
1.Implicit Grant
2.Resource Owner Password Credentials Grant
3.Client Credentials Grant
4.Authorization Code Grant
I have done research on the different authentication methods that we can use to secure the web api. But still confused on which one to apply in this scenario as this new web api is going to be made available in internet.
I already tried developing a POC with the OAuth 2.0 with password grant type referring this article. But when I read articles in the internet I found that the password grant type is not that secure and is deprecated.
Could you please advise on which grant type(client credentials/authorization code/implicit) to use in this scenario. I believe authorization code is used when the user is directly trying to access the API. In this scenario, SailPoint will be calling the API in the backend programmatically when they insert a new user in their UI.
I think it's a good approach to use client credentials in this case because the communication between IIQ and your Web API can be considered an API-to-API communication, I mean, IIQ is acting on behalf of itself in this communication.
See this article for more details - https://dzone.com/articles/four-most-used-rest-api-authentication-methods (bold part by myself)
OAuth 2.0 provides several popular flows suitable for different types
of API clients:
Authorization code — The most common flow, it is mostly used for
server-side and mobile web applications. This flow is similar to how
users sign up into a web application using their Facebook or Google
account.
Implicit — This flow requires the client to retrieve an
access token directly. It is useful in cases when the user’s
credentials cannot be stored in the client code because they can be
easily accessed by the third party. It is suitable for web, desktop,
and mobile applications that do not include any server component.
Resource owner password — Requires logging in with a username and
password. In that case, the credentials will be a part of the request.
This flow is suitable only for trusted clients (for example, official
applications released by the API provider).
Client Credentials —
Intended for the server-to-server authentication, this flow describes
an approach when the client application acts on its own behalf rather
than on behalf of any individual user. In most scenarios, this flow
provides the means to allow users to specify their credentials in the
client application, so it can access the resources under the client’s
control.

Using Google OIDC with code flow and PKCE

after trial and error it seems to me that Google OIDC does not support the code flow without supplying the client secret:
https://developers.google.com/identity/protocols/oauth2/native-app#exchange-authorization-code
According to the latest best practices for SPAs (https://datatracker.ietf.org/doc/html/draft-ietf-oauth-security-topics-13), code flow + PKCE is the recommended way to handle authentication. Is anyone aware of any trick required to make Google's code flow accept the code_challenge rather than the client_secret? Perhaps a dummy secret?
As of August 2020 the best practices document cited is still in draft and being activly updated - head revision here: https://datatracker.ietf.org/doc/draft-ietf-oauth-security-topics/. Googles' OAuth2 implementation has not yet applied the "work in progress" recomendation of PKCE being applied to web applications. SPAs are still directed to use the implicit flow in Googles' online documentation: https://developers.google.com/identity/protocols/oauth2/javascript-implicit-flow).
The standard for PKCE (https://www.rfc-editor.org/rfc/rfc7636) details that it was developed as a mitigation for authorisation code interception attacks found on mobile platforms and was originally recommended for implementation by native clients. Google's documentation for "Mobile and Desktop apps" does direct developers to use a PKCE Authorization Code flow. Clients using Google Android, iOS or windows store credential types with PKCE may omit the client_secret (see the note on the refresh token parameter table - and confirmed by Cristiano).
It is now recognised that PKCE eliminates the need for any public clients to store a client secret, and as such can be used to deprecate the implicit flow which always had the flaw of including returned access and identity tokens in a redirect URI. https://developer.okta.com/blog/2019/05/01/is-the-oauth-implicit-flow-dead.
The draft IETF document states in section 2.1.1 that this recognition is likely to become a published standard.
Hopefully Google will update its implementation to remove the requirement for a client_secret for a PKCE token request when the best practices becomes accepted. In the meantime it seems we have no choice but to continue writing SPAs using the implicit flow.
A good alternative IMHO consists in using Keycloak as IDP and then adding Google to the delegate identity providers of your Keycloak instance (and then Facebook and then any other idp if required). Keycloak implements the PKCE flow or whatever flow in the Oauth 2 RFCs in a reliable way. That means you need a hosted instance of Keycloak though.
Well, I'm using openId Connect authorization code with pkce without using client_secret in an android app using this lib: https://github.com/openid/AppAuth-Android.
I just had to ensure that the custom scheme was set using the app's package name from the manifest and use it to register the android credential on google console.

oauth2 openid connect javascript (electron) desktop application

What is the correct oauth2 flow for a desktop application? Besides a desktop application I have a SPA Web GUI which does use the Implicit flow. There it does not matters if the client Redirects after 3600s to the IdP to issue a new Access token.
But the desktop application needs to be running 24/7 or could be running 24/7. So it needs to automatically refresh the access token via a refresh_token. But since the implicit flow does not provide refresh tokens it is probably the wrong flow for a desktop app, isn't it?
I guess I need the auth code flow, which does provide a refresh_token. But authentication requests needs a redirect_uri. Let's say I want to use Google as my openid provider. With google it looks like I can't register client credentials with a custom URI scheme (https://developers.google.com/identity/protocols/OpenIDConnect). What does work is to register for example http://localhost:9300, which theoretically could be handled by the app.
A
Whats the correct oauth2 flow for a desktop app to receive a refresh_token?
B
Can I catch the redirect_uri via a custom URI scheme without using the implicit flow (Google IdP)? It is way easier to listen for a custom uri scheme than listening on a local tcp port.
C
This is more a general question. Usually desktop apps are public apps, so I should not include client_secret right? So the only flow which would be left is the implicit flow. But how can I renew access tokens according to specs without bother the desktop user every 3600s?
In my case I could publish the app locally so not public, but how is it for a public app?
A - Authorization Code Grant
B - Not sure here, You can register a Custom URI Scheme
C - Not enough information provided.
Are you using the AppAuth libraries? If so you SHOULD use PKCE and then additional security measures for the refresh token should not be necessary, on the assumption that the client never sends the refresh token with anyone other than the IDP over a secure connection.
Does this help?
A: Yes use the code grant
B: yes use a custom scheme. In your case you should use the reverse of your client ID. e.g. com.googleusercontent.apps.123 is the reverse DNS notation of the client ID. Register your client as "Other" in the Google developer console.
C: Yes, it should not include the client secret. That is why you don't need to send the secret for native clients ("Other") when exchanging the code for a refresh token. Just leave that field blank and it'll work.
As suggested by jwilleke, please use an AppAuth library if it is available for your use case as it'll also handle some of the security issues (PKCE).
For native apps (Desktop), you can follow OAuth 2.0 for Native Apps. But this is still under review and you can refer the latest draft from provided link.
With this flow, you can use authorisation code flow to obtain both access token and a refresh token. Refresh tokens should solve the UX related issue when it comes to extended app usage (24/7 and beyond).
According to this working document, there are strict guidelines on client authentication. Section 8.5 discuss about them. As it says client credentials are not recommended
For this
reason, and those stated in Section 5.3.1 of [RFC6819], it is NOT
RECOMMENDED for authorization servers to require client
authentication of public native apps clients using a shared secret
Also as nvnagr has mentioned in his answer, PKCE [RFC7636] is a must to have for native public clients.

OAuth 2.0 for REST Web services

i'm implementing a REST layer for an existing application. I have my userid and passwords stored in database and i would like to authenticate these credentials while calling my REST services. Note that this is a standalone application.
After investigation, I figured out 2 ways.
Basic implementation with HTTPS - this approach makes sure that
userid and password passed is not tampered by Man in middle attack.
Using Authentication Token(JWT) - user initially passes his userid
and password and server gives back an Authentication token.Once user
have an authentication token that could be used for subsequent
request.
Using OAuth 2.0 - I'm very confused in this approach. After reading the docs and specification, I found that since my application
is standalone, I need to implement Authorization Server, Resource
Server etc.
I'm asked to implement OAuth here, but i'm not convinced that OAuth is required in this scenario. I'm more inclined towards just implementing JWT(tokens)
Is OAuth really mandated in this scenario. What i understand about OAuth is it is used when you already have a service like Facebook/ Google.
Could someone pls confirm if my train of thoughts are correct and if OAuth 2.0 is required in this case?
The primary goal of OAuth 2.0 is to allow users to authenticate to use a client application via a third-party authentication provider (e.g. Google, Facebook, etc.), without exposing their credentials (typically a username/password) to the client.
In your case, if users are only ever going to authenticate to your system using their credentials in your database, then implementing OAuth 2.0 doesn't add any substantial value for you.
The OAuth 2.0 specification does define a "Resource Owner Password Credentials grant", intended for legacy use cases, that would apply to your situation: a user sends credentials, and you return an access token (that could be a JWT, if you like). If it's desirable from a management or marketing perspective, you could implement the Resource Owner Password Credentials grant and legitimately state that your application "conforms to a subset of OAuth2, as defined by RFC6749".

Do I need to implement OpenID as well as OAuth 2 to provide OAuth-style API authentication and authorisation?

We're building a new app that requires access to specific customer data, and OAuth appears to be absolutely perfect for our requirements - long-lived access tokens, ability to grant access to specific resources or scopes, and so on. We are not looking for 'log in with Facebook' type capabilities here; we want to expose a single, specific OAuth authentication server based on our existing customer login database, and allow web and native apps to authenticate users via this endpoint.
I've been looking at the DotNetOpenAuth code samples, and it appears that all of the OAuth 2 examples use OpenID to perform the initial authentication and then use OAuth to actually authorise access to resources.
My understanding is that you can use a 'no-op authorisation' to perform the initial authentication, allowing you to use OAuth2 for the whole process; since we don't want to support federated authentication, OpenID doesn't actually offer anything, and so I'd rather stick to a single protocol for simplicity if possible.
Is there a good example anywhere of a pure OAuth2 authentication server built using .NET? Have I misunderstood the example code supplied with DotNetOpenAuth? Or is OpenID still required for the initial authentication phase?
There's no coupled relation between OAuth2.0 and OpenId.
You can implement your custom login strategy in your OAuth2.0 implementation.
Since you gonna be the "Resource Owner"(as far as I understood your application owns the user base), you can simply replace in the DNOA authorization server sample the openid login with the standard asp.net login.
OAuth2.0 protocol simply needs to verify a user identity in order to emit an access token: how that identity will be verified is totally up to you.

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