I am trying my hands on apigee. I have configured a proxy with oauth2.0 security.
Everything works fine. But I noticed that a new access token is generated everytime I hit the oauth2/accesstoken endpoint, eventhough the previous one has not expired.
So as a consequence my endpoint is accessible with more than one token at a time. I am not an oauth2 expert, but isn't this a security risk? If we have so many accesstokens floating around. Please clarify.
Is this the usual implementation of every oauth2 server or is it specific to apigee and if so why?
My assumption is that for a particular client key/secret there would be only one valid access token at any given time and when this expires, the client should request for a new token using refresh token. Is this wrong?
Use ResponseCache policy for lookup/populate cache. It's a read through cache policy.
Use PopulateCache and LookupCache Policy.
Related
I'm working on a web application that will be installed on-prem behind Azure App Proxy. I can authenticate with OAuth and access the app successfully, but the authentication token is only good for an hour, after which my application is kind of dead because none of its API calls make it through the proxy.
So I'd like a way to keep that access alive so that users don't have to re-authenticate every hour.
I know that there's a flow for exchanging a refresh token for a new access token, and I can do that. But it seems like the ability to pass through the proxy is not governed directly by that token, but by a cookie called AzureAppProxyAccessCookie. Since I don't know how to convert my refreshed access token to a valid cookie value, this doesn't seem to solve my problem.
Note that I don't manage the proxy, so just increasing the expiration time on the token issued by Azure isn't an option.
So is there a way to refresh the AzureAppProxyAccessCookie token, or otherwise keep the session alive without making the user re-authenticate?
You can define a token life time policy with a longer token lifetime and assign it to your application.
https://learn.microsoft.com/en-us/azure/active-directory/develop/active-directory-configurable-token-lifetimes#access-id-and-saml2-token-lifetime-policy-properties
https://learn.microsoft.com/en-us/azure/active-directory/develop/configure-token-lifetimes#create-a-policy-for-web-sign-in
If I authenticate with OpenID connect, I can authenticate my SPA ok.
How do I use the obtained access token now to access my own REST resources?
It's a simple question, but I don't find satisfactory answers.
A prominent answer I always find is 'use oidc when you don't have a backend'.
Now that makes me wonder if ever a webapp was created that didn't need a backend.
Oidc is almost always the answer when the question of storing a refresh token in the client pops up (like in 'use oidc, it's a better architecture and ditch the refresh token') but it doesn't really explain anything.
So when the user logs in with, say Google, he obtains an identity and an access token (to ensure that the user is who he claims he is).
So how do you use this to authenticate at your own REST service?
The only real way I see it as stateless is by sending another request at the server to the provider on every request to the REST api, to match the identity to the validity of the access token there.
If not, we fall back to the good 'ol session vs jwt discussion, which doesn't quite seem to click with the oidc because now we're duplicating authentication logic.
And the good 'ol refresh token in the browser is generally promoted as a bad idea, although you can keep access tokens in the browser session storage (according to the js oidc client library), autorefresh them with the provider and that's fine then (-.-).
I'm running again circles.
Anybody can lay this out for me and please break the loop?
Your SPA (frontend) needs to add an authorization header with access token to each API request. Frontend should implement the authorization code flow + PKCE (implicit flow is not recommended anymore) + it needs to refresh access token.
Your API (backend) needs to implement OIDC (or you can use "oidc auth" proxy in front of backend) - it just validates access token, eventually returns 401 (Unauthorized) for request with invalid/expired/... token. This token validation is stateless, because it needs only public key(s) to verify token signature + current timestamp. Public keys are usually downloaded when backends is starting from OIDC discovery URL, so they doesn't need to be redownloaded during every backend request.
BTW: refresh token in the browser is bad idea, because refresh token is equivalent of your own credentials
Watching this video, it details in OAuth2 that the client application first has to get the authorization grant from the Authorization server and then use that grant to get a token before being able to access the resource server. What purpose does the grant serve? Why not give the client the token right away after the user signs on with his/her username and password?
Because it is more secure, for some application types.
What you describe is so called authorization-code-flow. It is normally used for "classical" web applications, where only the backend needs to access resource server. The exchange of authorization code to access token happens on the backend and access token never leaves it. Exchange can be done only once and in addition client id and secret (stored on the backend) are necessary.
Single-Page-Applications often use implicit-flow where access token is delivered to the frontend directly in the URL.
See more here:
IdentityServer Flows
EDIT: Q: "I still don't see how it is more secure given that you have to have the grant in order to get the token. Why need 2 things instead of just 1 thing to access the resource? If someone steals the token, they can access the resource anyway – stackjlei"
"Stealing" access token will work independent on how your application acquires it. However, stealing access token on the backend is much more difficult than on the frontend.
Authorization code is delivered to the backend also over the frontend but the risk that someone intercepts and uses it is tiny:
It can be exchanged only once.
You need client-id and client-secret in order to exchange it. Client-secret is only available on the backend.
Normally, authorization code will be exchanged by your backend to access-token immediately. So the lifetime of it is just several seconds. It does not matter if someone gets hold of used authorization code afterwards.
In your scenario there could be two servers, an Authorization and a Resource one.
It could be only one as well, but let's imagine this scenario.
The purpose of the Authorization Server is to issue short lived access tokens to known clients. The clients identify themselves via their CLientID and CLientSecret.
The Authorization Server ( AS ) holds the list of clients and their secrets and first checks to make sure the passed values match its list. If they do, it issues a short lived token.
Then the client can talk to the Resource Server ( RS ), while the token is valid. Once the token expires, a new one can be requested or the expired one can be refreshed if that is allowed by the Authorization Server.
The whole point here is security, Normally, the access tokens are passed in the Authorization header of the request and that request needs to be over https to make sure that the data can't be stolen. If, somehow, someone gets hold of an access token, they can only use it until it expires, hence why the short life of the tokens is actually very important. That's why you don't issue one token which never expires.
You have different type of OAuth. On type doesn't require to use the 'grant' authorization. It depend who are the user/application, the ressource owner and the server API.
This way, you - as a user - don't send the password to the application. The application will only use the grant token to gain access to your ressources.
I think this tuto is a pretty good thing if you want more details
https://www.digitalocean.com/community/tutorials/an-introduction-to-oauth-2
A quick overview of the problem.
I have a client application that will use IDS to authorise access to a google service on behalf of the end user.
However, the client application isn't, itself responsible for talking to google. There is a Server app that does some magic with the user's data on his behalf.
Now, if I understand things correctly, the server app will use the Access Token supplied by the client app to talk to google. What happens when that access token expires? As I understand it the client application is expected to use the refresh token to as for a new access token.
Is there an issue with the server using this refresh token to update the access token? What flow am I supposed to use to make this magic happen?
A server using a refresh token to get a new access token is a valid use case.
If you're working with OAuth you can use the Client Credentials or Resource Owner flows to use refresh tokens, otherwise for OpenID Connect you'll need to use Authorization Code or Hybrid.
So I've got OpenID+OAuth hybrid working with DotNetOpenAuth when connecting to google. It gives me back a Authorized token so I need to exchange it for an access token.
I seem to be coming in about midway through a normal OAuth workflow in DotNetOpenAuth. I also seem to be missing somethings that DotNetOpenAuth wants like the the token secret and verifier. However according to the graph here I shouldn't need them.
Any ideas how to easily swap the auth token for an access token with DotNetOpenAuth?
Since you're talking about the OpenID+OAuth hybrid I expect you're writing a web app (as opposed to an installed app). DotNetOpenAuth should only be asking you for a verifier code if you're using the DesktopConsumer class, which is inappropriate for you. Use the WebConsumer class instead and the verifier will be taken care of for you. Swapping the request token for an access token will be automatic as you call the simple methods on WebConsumer, I hope.
As for the token secret, all token secrets are managed by your implementation of ITokenManager, which will save and retrieve token secrets on demand within your database.