Protect the API by token/api key - oauth-2.0

A newbie question about API security:
When I applied API service from some API providers, usually I just login and generate an api key or token in their api management site. After that I can embed this api key or token in the request to access the API.
I was told that the this is OAuth 2. But, after reading a few articles about OAuth 2, it seems the OAuth-2 token issued from OAuth server will expire and a refresh-token is required to fetch a new token.
But the API keys I got from those API providers does not mention about the expiration, instead, I can manually revoke the API Key on their API management site.
So, if I have some APIs which I want to use the similar way (let the user manage their own api key on my site) to protect, how can I achieve that by using the OAuth 2 server?

I think what you explained above are 2 different ways to authorize a request:
A. Using API Keys
These API keys are usually a long string that you generate inside a dashboard
You as a developer would usually have 1 API key throughout your app, and you append this API key to requests to the API provider
B. Using OAuth 2.0
OAuth 2.0 uses a different kind of token to authorize requests, it usually involves a short-lived access token and long-lived refresh token.
These tokens are usually for Users, each user will have a different token that expires every X days.
To acquire a token, the user has to "log in" to your site or an Identity Provider's site (like Google Accounts) and enter their credentials every time the token expires.
Here's a picture to show the difference:
If you want to provide an API service for other developers:
Use OAuth 2.0 to log in the developers to their dashboard (this means your server routes that interact with the dashboard would be protected by the OAuth 2.0 tokens, requiring the developer to log in to update some settings)
Use API Keys to access your provided API routes. Developers have to log in and generate API keys from the dashboard. Then they can use this API key to fetch resources from your API.
Here's a more thorough explanation about OAuth 2.0, access tokens, and how to implement it on your site.

Related

Access Token from OIDC vs OAuth2.0

I know that the access token obtained from OAuth2.0 can be used to access protected resources.
OpenID Connect issues ID token and access token after authentication. And the spec says that the access token can be used to access userinfo endpoint to get additional user information.
One thing I'm not able to understand is, is there any difference between the access token obtained in #1 vs #2. If there is no difference then do we need OAuth2.0, if we implement OIDC.
You tend to just implement both OIDC and OAuth 2.0 together as a combined flow, by plugging in an Open Id Connect security library.
Eg For a mobile app it is common to plug in AppAuth Libraries, which would give you this behaviour:
An OAuth 2.0 authorization redirect using response_type=code
The Open Id Connect part is initiated by including scope=openid
You then get an authorization code (OAuth 2.0)
You then swap the authorization code for tokens
You get an access token (the OAuth 2.0 part)
You also get an id token (the OIDC part)
In practical terms OIDC introduces some standardisation that makes developing UI flows and dealing with access tokens in APIs easier, eg:
Metadata endpoint, to tell us where all the other endpoints live
JWKS endpoint, from which we can get the access token's public key
Typically in my own code I do not use the id token much at all. However, it is best practice to receive one, so that libraries such as AppAuth can make extra verification checks against received tokens.
If it helps, my Message Workflow Blog Post summarises some messages and use of endpoints.
This access tokens have different audiences ("aud" claim): the OAuth 2.0 access token is intended for resource server (i.e. API), and OIDC access token is intended for identity server itself.
As for me, they cannot be used interchangebly, but some examples (e.g. IdentityServer4) do that without checking the "aud" claim.
PS. The single access token can be used for both purposes if both audiences are included:
Each principal intended to process the JWT MUST identify itself with a
value in the audience claim.<...> In the general case, the "aud" value
is an array of case-sensitive strings, each containing a StringOrURI
value.
JWT doc

Using JWT to authorize REST API requests after SAML Authentication

I'm struggling theese days on the possible way to configure an Authentication + authorization system to consume a REST API from a mobile application.
Scenario:
We've developed 3 independent portals for a big customer that serves several users.
To enable a SSO for the 3 portals we've implemented a SAML authentication system using SimpleSAMLphp.
Every portal has a service provider and they make assertion requests against a central IdP.
The IdP checks username and password against a database where passwords are hashed and stored during registration.
After the login, the authorization on the portals is handled by the session on the server, and so far everything was fine.
Now the customer asked us to develop a mobile application that will require the users to login and access several of their protected resources collected during the usage of the 3 portals.
We've decided to develop a frontend application using ionic that will consume a REST API made in node.js that will serve all the data (both protected and unprotected resources).
Now here comes the question: to authorize access to protected resources on the Api we'd like to use JWT to easily achieve a stateless system.
The doubt is how to perform the authentication? We've the opportunity to check the credentials directly against the database skipping the SAML process, otherwise we've to implement a solution where the SSO IdP acts as authentication provider and then when an attempt is successful the API app will get the response from the idp and then issue a signed jwt to the consumer client. Is this second way a common implementation? Is it possible?
What path do you suggest to follow? The first could be very easy to achieve, but since we're using html+js for the app's frontend, if we decide to use the second solution probably in the near future we could recycle some code from the app to modernize some functions on the web portals, maintaining the jwt pattern and consuming the new Api also on the web.
I believe that in this case will be easier to ask a token to the new api using someway the logged in user's data already in the session of the portal. Sounds possible?
I hope that everything was clear, any help will be appreciated!
Thanks
The key goal here is to code your apps in the best way, via
the latest security standards (OAuth 2.0 and Open Id Connect).
SAML is an outdated protocol that is not web / mobile / API friendly, and does not fit with modern coding models.
Sounds like you want to do OAuth but you do not have an OAuth Authorization Server, which is a key part of the solution. If you could migrate to one you would have the best future options for your apps.
OPTION 1
Use the most standard and simple option - but users have to login with a new login screen + credentials:
Mobile or Web UI uses Authorization Flow (PKCE) and redirects to an Authorization Server to sign the user in
Mobile or Web UI receives an access token after login that can be sent to the API
Access token format is most commonly a JWT that the API can validate and identify the user from
The API is not involved in the login or token issuing processes
OPTION 2
Extend option 1 to federate to your SAML Identity Provider - enables users to login in the existing way:
The Authorization Server is configured to trust your SAML based identity provider and to redirect to it during logins
The SAML idp presents a login screen and then posts a SAML token to the Authorization Server
The Authorization Server issues OAuth based tokens based on the SAML token details
OPTION 3
Use a bridging solution (not really recommended but sometimes worth considering if you have no proper authorization server - at least it gets your apps using OAuth tokens):
Mobile or Web UI uses Resource Owner Password Grant and sends credentials to a new OAuth endpoint that you develop
OAuth endpoint provides a /oauth/token endpoint to receive the request
OAuth endpoint checks the credentials against the database - or translates to a SAML request that is forwarded to the IDP
OAuth endpoint does its own issuing of JWT access tokens via a third party library (if credentials are valid)
Web or Mobile UI sends JWT access token to API
API validates received JWT access token

Which youtube credentials should I use?

I just want to fetch some data from the playlist, to make it work. Which Credentials do I need to use?
API keys
OAuth 2.0 client ID
If you are just getting playlist, searching YouTube videos via keyword or listing videos you can use API keys, but if you have to upload videos or access private user data you have to use OAuth 2.0 client ID.
OAuth 2.0: Your application must send an OAuth 2.0 token with any request that accesses private user data. Your application sends a client ID and, possibly, a client secret to obtain a token. You can generate OAuth 2.0 credentials for web applications, service accounts, or installed applications.
See the Creating OAuth 2.0 credentials section for more information.
API keys: A request that does not provide an OAuth 2.0 token must send an API key. The key identifies your project and provides API access, quota, and reports.
See the Creating API Keys section for information about creating an API key.
Hope this helps.

External API's Calling My API Secured with Azure Active Directory

If I have an API secured with Azure Active Directory, what is the flow when an external API wants to talk to my internal API?
Is this just an API to API call as normal or is this a special circumstance and needs handling a different way?
Is this just an API to API call as normal or is this a special circumstance and needs handling a different way?
The special circumstance may depend on the confidentiality of the resources served by these api(s) and the level of security your application needs. In the end it is an api to api call only.
There are two approaches you can use if Azure Active Directory (AAD) is your Identity Provider for the entire application.
Application Identity with OAuth 2.0 client credentials grant provided by AAD. The calling API makes a request to AAD token endpoint with its client id, client secret (credential) and the application id (the unique id for the callee API) to receive an access token as response. This token is used as Bearer token to call the downstream API. In this approach client id, client secret, application id that are exchanged for an access token, are static values. Some one who has access to these values may find a way to compromise application security (highly unlikely).
The second approach is Delegated User Identity with OAuth 2.0. A request is made to AAD token endpoint with client id, client secret, the access token received as part of calling the tier1 API and a special on_behalf_of parameter to receive an access token, refresh token as response. We preferred this approach as it uses a dynamic value (access token from tier1 api) and also provides a refresh token.
You can read more about these approaches here
If you do not want to use AAD, you can use asp.net built in OwinAuthenticationMiddleware to generate and validate your own access tokens. As said earlier it all depends on your application requirements and implementation details, but in the end it is an API to API call.
Hopefully this is helpful, please let me know if you have any questions.
Thank you,
Soma.
oAuth is done for loggin user to a webservice (see also reference here).
Use OAuth to give your users access to their data while protecting their account credentials.
As another webservice wants to consume one of your service best way to do so is to have another authentication method in order to authorize
Other API, I assume you are talking of machines and not users (alias humans).
So best way is to provide another auth mechanism in order to authorize machines to connect to your API in a safe way.
A simple way to do a machine connection is using a private PKI with public/private key.
A good reference for PKI : http://docs.oracle.com/javase/6/docs/technotes/guides/security/certpath/CertPathProgGuide.html

Access my token while keeping it secret (omniauth)

I'm using Omniauth to link API with users. Currently I have my site's token and secret in the omniauth.rb file. How can I grab that data for API GET requests? If I can't, where should I store it and how should I retrieve it?
Thanks
I presume you're not familiar with OAuth itself. In order to implement your API interactions effectively, I advise you to read Beginner's Guide to OAuth.
Basically, you're going to register your consumer application in provider application. During that process, you will obtain a secret token, associated with your consumer app. Using that token to identify your consumer application, provider will generate access token for each subsequent request. These tokens are short-lived and basically allow only one requrest to API.

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