3-legs in OAuth 2.0 - oauth-2.0

I'm making a program uses Youtube API for testing purpose.
Because my program is an installed-application, I've found a picture pointing out how to implement authentication.
It's what I have:
Immediately, I'm confused. According to this figure, I don't know why Google Servers just returns Authorization code after User login and consent.
Why doesn't Google Servers return Token instantly?

You are Confused because, I guess, you have missed 3rd leg "User". Authorization code represents the User Consent.
Google server returns Authorization code when User grants the permission to your app to get his/her data from google server(resource server). if user denies the permission Google server wont generate the Authorization code and your app wont be able to get access token.
Another use of Authorization_code is to keep resource owners credentials secret. Authorization code is shared with client and client exchanged that code for access_token.
Find more Information about Oauth 2.0 in this article.

Related

Microsoft Graph API Logic App Authentication

I am having a difficult time getting a Microsoft Graph API call to work. Specifically, I am having a hard time with the authentication process working. I followed the directions in this article
http://martink.me/articles/using-microsoft-graph-in-logic-apps
However, when I make the api call of https://graph.microsoft.com/v1.0/me/messages/{id}, I get the error:
Current authenticated context is not valid for this request. This occurs when a request is made to an endpoint that requires user sign-in. For example, /me requires a signed-in user. Acquire a token on behalf of a user to make requests to these endpoints. Use the OAuth 2.0 authorization code flow for mobile and native apps and the OAuth 2.0 implicit flow for single-page web apps.
I then added an oAuth token call to get a token. Then I used that token in the Authorization header when making the Microsoft Graph Api call. I still get the same error.
Can anyone provide guidance on how best to make an Graph Api call in LogicApps? Do I only need the authentication discussed in the article? Or, do I need to call the Graph Api with an Authorization token? Do I need to make an oAuth authorization call before I make the oAuth token call?
This exception is caused by the token acquired using the client credentials flow. In this flow, there is no context for /Me.
This type of grant is commonly used for server-to-server interactions that must run in the background, without immediate interaction with a user(no user logged in).
For your problem, you are using client credential flow and you are granting application permissions, so you should request /users.
GET https://graph.microsoft.com/v1.0/users/{id | userPrincipalName}/messages/{id}

Why does Postman require user login for Google oauth?

I'll try to connect to the content api for shopping via API.
I'de tried some different oAuth ways (e.g. "three-step-method" with access key and baerer-token) but for a spezific integration I need the "credentials-oAuth".
Currently I tried as following:
https://accounts.google.com/o/oauth2/v2/auth?
client_id=[my client id]&
scope=https://www.googleapis.com/auth/content&
redirect_uri=[some random request bin -> added in Authorised redirect URIs ]&
response_type=code
If I call this via Postman, I'll be redirected to the login page of Google. But why?
How can I solve this problem?`
BG
David
Shopping API data is private user data. In order for your application to access private user data it must have the permission of the user who owns that data.
We use OAuth2 to do that. The user must consent to your application accessing its data. In the below image the application Google analytics windows is asking the user for permission to access their Google analytics data.
If I call this via Postman, I'll be redirected to the login page of Google. But why?
You are seeing a login screen with Postman is simple the user needs to be logged in before they can grant access to their data.
How can I solve this problem?
You dont as there is no problem the user must login to grant your client application consent to its data. This is working exactly as it should
Service accounts
Update to answer comment Service accounts are special Google accounts that can be used by applications to access Google APIs programmatically via OAuth 2.0. A service account uses an OAuth 2.0 flow that does not require human authorization. Instead, it uses a key file that only your application can access. This guide discusses how to access the Content API for Shopping with service accounts.

How to implement OpenID Connect authentication with 3rd party IDPs in a microservices architecture

For the past 10+ days I've read an watched ALL the content I could find on understanding OAuth2 and OpenID Connect, only to find that many people disagree on the implementation, which really confuses me.
To my understanding, all the articles and examples I found assume you want access to eg. google calendar, profile info or emails if you eg. login with google, but I do NOT need to access other than my own API's - I only want to use Google, Facebook etc for logging in, and getting an id which I can link to my user in my own database - nothing more than that.
I'll try illustrate my use case and use that as an example.
A note on the diagram: the Authentication service could probably be built into the API Gateway - not that i matters for this example, since this is not about "where to do it", but "how to do it the best way" possible, for an architecture such as mine, where it's used for my own API's / Microservices, and not accessing Google, Facebook etc. external API's
If you can understand what I'm trying to illustrate with this diagram above, please tell me if I've misunderstood this.
The most basic requirements for this architecture you see here are:
Users can login with Google, Facebook, etc.
The same login will be used for all micro-services
OpenId user will have a linked account in the database
User access is defined in my own db, based on groups, roles and permissions
I do not intend to use external API's after the user is authenticated and logged in. No need for ever accessing a users calendar, email etc. so I really just need the authentication part and nothing else (proof of successful login). All user access is defined in my own database.
So a few fundamental questions comes to mind.
First of all, is OpenID Connect even the right tool for the job for authentication only (I'll have no use for authorization, since I will not need read/write access to google / facebook API's other than getting the ID from authenticating)?
People generally do not agree on whether to use the ID or Access token for accessing your own API's. As far as I understand the ID token is for the client (user-agent) only, and the access token is for eg. accessing google calendar, emails etc.... External API's of the OpenID Provider... but since I'll only be accessing my own API's, do I event need the access token or the ID token - what is the correct way to protect your own API's?
If the ID token is really just for the client, so it can show eg. currently logged in user, without going to the DB, I have 0 use for it, since I'll probably query the user from from the db and store it in redux for my react frontend app.
Dilemma: To store user details, groups, roles and permission inside JWT or not for API authorization?
By only storing the user identifier in the token, it means that I always allow authenticated users that has a valid token, to call endpoints BEFORE authorization and first then determine access based on the db query result and the permissions in my own database.
By storing more data about the user inside the JWT, it means that in some cases, I'd be able to do the authorization / access (group, role, permission) check before hitting the API - only possible with user info, groups, roles and permission stored inside a JWT issued upon login. In some cases it would not be possible due to eg. the CMS content access permissions being on a per-node level. But still it would mean a little better performance.
As you can see on the diagram I'm sending all API requests through the gateway, which will (in itself or with an authentication service) translate the opaque access token into some JWT with an identifier, so I can identify the user in the graph database - and then verify if the user has the required groups, roles and permissions - not from an external API, but from my own database like you see on the diagram.
This seems like a lot of work on every request, even if the services can share the JWT in case multiple services should need to cross call each other.
The advantage of always looking up the user, and his permissions in the db, is naturally that the moment the user access levels change, he is denied/granted access immediately and it will always be in sync. If I store the user details, groups, roles and permission inside a JWT and persist that in the client localstorage, I guess it could pose a security issue right, and it would be pretty hard to update the user info, groups, roles and permissions inside that JWT?
One big advantage of storing user access levels and info inside the JWT is of course that in many cases I'd be able to block the user from calling certain API's, instead of having to determine access after a db lookup.
So the whole token translation thing means increased security at the cost of performance, but is is generally recommended and worth it? Or is it safe enough to store user info and groups, roles, permissions inside the JWT?
If yes, do I store all that information from my own DB in the ID Token, Access token or a 3rd token - what token is sent to the API and determines if the user should be granted access to a given resource based on his permissions in the db? Do I really need an access token if I don't need to interact with the ID providers API? Or do I store and append all my groups, roles, permissions inside the ID token (that doesn't seem clean to me) issued by OpenID connect, and call the API and authorize my own API endpoints using that, even if some say you should never use the ID token to access an API? Or do I create a new JWT to store all the info fetched from my database, which is to be used for deciding if the user can access a given resource / API endpoint?
Please do not just link to general specs or general info, since I've already read it all - I just failed to understand how to apply all that info to my actual use case (the diagram above). Try to please be as concrete as possible.
Made another attempt to try and simply the flow:
The following answer does only apply for a OpenID Connect authentication flow with a 3rd party IDP (like Google). It does not apply for an architecture where you host your own IDP.
(There are some API gateways (e.g Tyk or Kong) which support OpenID Connect out of the box.)
You can use JWTs (ID token) to secure your APIs. However, this has one disadvantage. JWTs cannot be revoked easily.
I would not recommend this. Instead you should implement an OAuth2 authorization server which issues access tokens for your API. (In this case, you have two OAuth2 flows. One for authentication and one for authorization. The ID and access token from the IDP are used only for authentication.)
The following picture shows a setup where the API gateway and authentication/authorization server are two separate services. (As mentioned above, the authentication/authorization can also be done by the API gateway.)
The authentication flow (Authorization Code Grant) calls are marked blue. The authorization flow (Implicit Grant) calls are marked green.
1: Your web app is loaded from the app server.
2a: The user clicks on your login button, your web app builds the authorization URL and opens it. (See: Authorization Request)
2b: Because the user hasn't authenticated and has no valid session with your authorization server, the URL he wanted to access is stored and your authorization server responds with a redirect to its login page.
3: The login page is loaded from your authorization server.
4a: The user clicks on "Login with ...".
4b: Your authorization server builds the IDP authorization URL and responds with a redirect to it. (See: Authentication Request)
5a: The IDP authorization URL is opend.
5b: Because the user hasn't authenticated and has no valid session with the IDP, the URL he wanted to access is stored and the IDP responds with a redirect to its login page.
6: The login page is loaded from the IDP.
7a: The user fills in his credentials and clicks on the login button.
7b: The IDP checks the credentials, creates a new session and responds with a redirect to the stored URL.
8a: The IDP authorization URL is opend again.
(The approval steps are ignored here for simplicity.)
8b: The IDP creates an authorization and responds with a redirect to the callback URL of your authorization server. (See: Authentication Response)
9a: The callback URL is opened.
9b: Your authorization server extracts the authorization code from the callback URL.
10a: Your authorization server calls the IDP's token endpoint, gets an ID and access token and validates the data in the ID token. (See: Token Request)
(10b: Your authorization server calls the IDP's user info endpoint if some needed claims aren't available in the ID token.)
11a/b: Your authorization server queries/creates the user in your service/DB, creates a new session and responds with a redirect to the stored URL.
12a: The authorization URL is opend again.
(The approval steps are ignored here for simplicity.)
12b/+13a/b: Your authorization server creates/gets the authorization (creates access token) and responds with a redirect to the callback URL of your web app. (See: Access Token Response)
14a: The callback URL is opened.
14b: Your web app extracts the access token from the callback URL.
15: Your web app makes an API call.
16/17/18: The API gateway checks the access token, exchanges the access token with an JWT (which contains user infos, ...) and forwards the call.
A setup where the authorization server calls the API gateway is also possible. In this case, after the authorization is done, the authorization server passes the access token and JWT to the API gateway. Here, however, everytime the user infos change the authorization server has to "inform" the API gateway.
This is a very long question. But I believe most can be summarised by answering below,
To my understanding, all the articles and examples I found assume you want access to eg. google calendar, profile info or emails if you eg. login with google,
You do not necessarily use Access token (ID token in some occasions) to access the services offered by token issuer.You can consume tokens by your own APIs. What these Identity Providers (synonym to Authorization server, or IDP in shorthand) is to hold identities of end users. For example, typical internet have a Facebook account. With OAuth and OpenID Connect, the same user get the ability to consume your API or any OAuth/OIDC accepted service. This reduce user profile creation for end users.
In corporate domain, OAuth and OIDC serves the same purpose. Having a single Azure AD account lets you to consume MS Word as well as Azure AD's OIDC will issue tokens which can be used to Authorise against an in-house API or an third party ERP product (used in organization) which support OIDC based authentication. Hope it's clear now
A note on the diagram is that the Authentication service could probably be built into the API Gateway - not sure if that would be better?
If you are planning to implement an API gateway, think twice. If things are small scale and if you think you can maintain it, then go ahead. But consider about API managers which could provide most of your required functionalities. I welcome you to read this article about WSO2 API manger and understand its capabilities (No I'm not working for them).
For example, that API manager has built in authentication handling mechanism for OAuth and OIDC. It can handle API authentication with simple set of configurations. With such solution you get rid of the requirement of implement everything.
What if you can't use an API manager and has to do it yourself
OpenID Connect is for authentication. Your application can validate the id token and authenticate end user. To access APIs through API Gateway, I think you should utilise Access token.
To validate the access token, you can use introspection endpoint of the identity provider. And to get user information, you can use user-info endpoint.
Once access token is validated, API gateway could create a session for a limited time (ideally to be less or equal to access token lifetime). Consequent requests should come with this session to accept by API gateway. Alternatively, you can still use validated access token. Since you validated it at the first call, you may cache for a certain time period thus avoiding round trips to validations.
To validate user details, permission and other grants, well you must wither bind user to a session or else associate user to access token from API gateway at token validation. I'm also not super clear about this as I have no idea on how your DB logic works.
First Appreciate your patience in writing a very valuable question in this forum
we too have same situation and problem
I want to go through ,as images are blocked in our company in detail
Was trying to draw paralles to similar one quoted in the book
Advance API In Practise - Prabath Siriwerdena [ page 269]Federating access to API's Chapter. Definitely worth reading of his works
API GW should invoke Token Exchange OAUTH2.0 Profile to IDP [ provided the IDP should support TOken Exchange profile for OAUTH 2.0
The Absence of API Gateway , will result in quite bespoke development
for Access Control for each API Check
you land up in having this check at each of the api or microservice [ either as library which does work for you as a reusable code]
definitely will become a choking point.]

Is it possible to authenticate server to server with Google Calendar API?

So I read the following on the Authorizing Requests to the Google Calendar API page written by Google folks.
Your application must use OAuth 2.0 to authorize requests. No other authorization protocols are supported. If your application uses Google Sign-In, some aspects of authorization are handled for you.
My knowledge of OAuth 2.0 is limited so I'm not sure if that means that I cannot get a one-time auth token for a user?
I'm building an app that will need to CRUD events for a user in the background based on other stuff. So I can't have the user authenticate over and over again. Is there a way around here?
If not, is there an Google Calendar alternative that has a dependable API that I could use?
When the user authenticates your application you are given an Access token (good for one hour) and a refresh token. You should save the refresh token, when ever you need to access the users data you can take the refresh token and ask Google to give you a new access token. It is the access token which gives you access to there account.
I wrote a tutorial that tries to explain Oauth2 how to set it up and how it works. Google Developer console Oauth2

Difference between Access Grant and Access Token

I can't figure out the difference between Token and Grant in Doorkeeper. In which moment, Doorkeeper creates an Access Grant and when an Access Token? The documentation doesn't seems to say nothing about it and now I'm reading the code but is not a dozen lines.
I recommend to also read the documentation of oauth2
As I understand, Doorkeeper is based on the protocol described in that documentation too.
In doorkeeper, you will get access grant first and then access token.
Access grant usually only lives very short (the default in doorkeeper is 10 minutes).
You will get this by requesting GET to api-url/oauth/authorize (don't forget to put client_id, redirect_uri, and response_type as parameter. response_type will have value "code").
Once user allow the apps (user clicks "allow" button), doorkeeper will return the access grant as parameter in the returning url.
Get that code and you can now use it to make POST request to api-url/oauth/token to get your access_token and refresh_token.
Using access_token, you can get the resources of the API in a limited time (Doorkeeper's default is one hour if I'm not mistaken).
When acces_tooken expired, use refresh_token to get new access_token and so on.
In summary, access grant is the key that given as the sign that user has allowed the apps to use its resources.
Access token is the key that is given to permit an apps to use resources in a limited time which has defined.
Hope it can help.
I'm assuming you're talking about the Web Server flow, as you're using a Ruby gem in a Rails app (as you know, there are 4 flows).
Usually in the Web Server flow, Grant is the moment when the user clicks in a link to consent authorization: he/she will be asked to authorize the app to read/write data.
If consent is granted, then the app will get a temp code. With this code, in the background, the app will ask the Token for the service provider.
Then, only with the Token, the app will be able to use the service provider APIs.

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