For authenticating end users to things like IoT services, many cloud services have a custom option: The client authenticates with the dev's own server (however the dev implements that), which in turn gets a token from the cloud service and sends that to the client for authentication with the cloud service. Amazon and Twilio are examples of this. This allows for a fully customizable auth.
If I understand correctly, Google Cloud Platform requires end users to authenticate with Google's OAuth2 service, meaning they must sign in with a Google account. I don't see any way around this, but the limitation is so severe that I wonder if I'm missing something. Is there some way I can instead authenticate users my own way?
meaning they must sign in with a Google account
That's not entirely correct, you probably overlooked this in the very doc you referenced (emphasis mine):
Firebase Authentication gives you a robust, secure authentication
system-in-a-box that helps you do sign in with any account your
users want to use. Firebase Authentication supports password
authentication in addition to federated sign in with Google, Facebook,
Twitter, and more, allowing you to easily scale your authentication
system as you grow on desktop and mobile.
So you can have your users choose their username and password or login using one of their supported 3rd party non-Google accounts.
But it will still be Google handling the authentication for you, which is good if you plan to use other GCP products/services as the authentication can be propaged.
If you want to handle the authentication yourself - nothing stops you from doing that, but it may be difficult/impossible to integrate it with other GCP products/services. The Plain OAuth 2.0 might be what you're looking for (I don't understand it enough), search for it in the Compare Auth Options guide.
Related
I have been doing a lot of research into how to authenticate mobile apps with an API - I still feel a bit unsure about which flow & architecture would be better to use in my particular use case.
I think what's confusing me is some of the terminology used.
My use case:
An API & database on one server. Which holds the users & and the users resources.
A web app, which I have built and consumes the API. Hosted on the same server as the API. So it's dogfooding.
A web app, which I have built and consumes the API. Hosted on a different server to the API.
A mobile app, which I have built and consumes the API.
I'd like to be able to authenticate with the API using username & password.
The API will never be opened up for consumption by other 3rd party services except the web app and the mobile app.
Initially I felt like using the Resource Owner Password Credentials Grant flow would be sufficient. However in the docs it states that this flow should be used if "The client is absolutely trusted with the user credentials".
Since both my mobile & web apps will be built by me, I'm assuming they are seen as 1st party clients. Therefore am I right in thinking they are considered to be trusted with the user credentials? As I typically thought that when implementing oAuth, the idea would be to have the authentication server separate from the resource server. Which would allow you to have one authentication server for multiple APIs.
After reading this post: Why the Password Grant is not suitable for modern applications
It threw me off track a bit. But then, is this post talking about using this flow in my use case?
I was also looking at the Implicit Grant Tokens flow. However using this flow I couldn't really see how the user would enter their credentials first?
I also question if any of the oAuth flows is really needed for my use case and I should instead look at other ways of authenticating?
I'm really quite lost with this I would like some direction to go in with how to authenticate users in my particular case.
Thanks in advance!
I'll most likely be using Laravel to house my API and so I do have Passport available to me to implement oAuth
EDIT
From following this oauth article I've found that in all use cases of my app, I end at Password Credentials Grant flow. Would I be correct here?
I'm trying to figure out what I need to do in order to achieve seamless SSO sign up.
When an administrator of a domain installs my google app, all of the users on his/her domain, should be able to sign-in through SSO without seeing any confirmation prompts. I'm looking into documentation on how to set this up:
Instead of displaying a confirmation page, your application should
match the value of the openid.realm parameter in the OpenID request
against the value declared in the application's manifest.
Is there an example of this? Also, I think Google stopped using XML manifest files once they switched from OpendID to OAuth 2.0. If so, how does this whitelist process work with OAuth 2.0?
Should I be utilizing Google Admin SDK?
Since google is moving away from OpenId, white listing instructions are obsolete. Found a blog post about Domain-wide delegation with Oauth 2.0. Google recommends the following:
the recommended authorization mechanism is now to use OAuth 2.0 and
service accounts. Google Apps domain administrators can delegate domain-wide authority to the service account’s credentials for a set of APIs. This results in allowing the application, by using the service account’s credentials, to act on behalf of the Google Apps domain’s users.
instructions on how to set up domain wide delegation - https://developers.google.com/drive/web/delegation
you can find detailed step to achieve seamless SSO sign up at the following url
http://david-codes.blogspot.com/2014/07/how-to-provide-seamless-single-sign-on.html
We have several apps Deployed on Google Apps Marketplace using OAuth 1.0 protocol. According expiration OAuth 1.0 in Google Platform we are trying to migrate all the apps to new OAuth version but we are facing some difficulties regarding background request to Google Admin SDK Directory API.
In our apps we need to request for Domain user accounts, groups and other stuff related Email Domain structure. Until OAuth 1.0 we have been doing this with 2-LO (Two-Legge OAuth) so basically once Admin gave us access we can impersonate request for domain using this mechanism.
After reading all Google Documentation about Google API, Oauth Mechanisms and stuff, and after trying some code test hypothesis too, we haven't figured out yet how can we managed the same concept with OAuth 2 because of the following:
Using Web Server Oauth 2 Strategy simply will not work because in that scenario we would be getting a Domain user Access to Admin SDK. If we keep their access/refresh token pair to later querying Admin SDK and the user is deleted because Domain change it Admin we will be disconnected from flow.
I supposed in that case the best choice was Service Account strategy. The problem with this scenario is the user has to manually configure access to the App in their Admin Console according to the Google's document domain-wide delegation authority (https://developers.google.com/+/domains/authentication/delegation#create_the_service_account_and_its_credentials). This is really awkward for us since we were managing all application installation interactively and we don't want to remove User Experience facilities.
Finally, my questions are:
Is there any way to do domain-delegation authority with OAuth 2 with no manual user configuration, full interactively?
Is there any way to do this without needing user email, which in fact is one of the parameters in Service Account Oauth2 Strategy?
Must we keep 2-LO Authentication for this scenario and do OAuth 2 only for installation Google Marketplace part?
Any comments or guide will be wellcome.
Best,
Certainly - in the latest update to the Google Apps Marketplace, the act of installing an App means the admin doesn't need to do an additional manual step.
You need a way to impersonate a user in a Service Account. Depending on how you implement your application, you might need to utilize the Directory API.
OAuth1 is going away eventually so I recommend you use OAuth2 throughout to simplify your code complexity.
I am currently developing a web application that is right now comprised of a front end which displays and interacts with the data using a REST API we have written. The only thing that will ever use the API is our front end website, and at some point a mobile app that we will develop.
I have done a lot of reading about how OAuth is the ideal mechanism for securing an API and at this point I am starting to have a good understanding of how it works.
My question is -- since I am never granting access to my API to a third-party client, is OAuth really necessary? Is there any reason it is advantageous? Furthermore, because the back end is simply the API, there is no gateway for a user to authenticate from (like if you were writing an app using the Twitter API, when a user authenticates they would be directed to the Twitter page to grant to access then redirected back to the client).
I am not really sure which direction to go in. It seems like there must be some approach halfway between http authentication and OAuth that would be appropriate for this situation but I'm just not getting it.
From my point of view, one of the scenarios that favor OAuth over other options is to work with untrusted clients, no matter if these are developed by you or a third party.
What's an untrusted client? Think from the point of who handles the credentials that grant access to your API.
For example, your web application could interact with your API in two falvors:
Your web app server side talks to your API. Your web app server is a trusted client because the credentials to access your API can only be access by whom have access to the server...You and your team. You could authenticate your web app server with a client_id and a client_secret.
You may want to make calls directly to your API from your Web app client, which runs on the end user's browser using JavaScript. The end user's browser is an untrusted client. If you were to deliver the credentials to your API down to the browser, anyone could check the JavaScript code and steal your credentials.
A third party Native App is also untrusted. A malicious developer that uses your API could save the credentials of and end user of your platform.
Your Native App is a trusted client and could manage the authentication with a simple username , password and a client id identifying your App.
How can OAuth help? OAuth Authorization code and Implicit grants can help you with this issue. These flows only work with clients that support a redirect, like a browser. And let you authenticate an untrusted client and a user against your Authorization Server to gain access to your Resource Server, your API, without exposing the credentials. Take a look at the RFC to see how it is done.
The good thing of OAuth is that it not only supports these redirect based authentication flows, but it also supports client credentials grant and user credentials grant. So an OAuth Authorization Server would cover all cases.
OAuth 2.0 originally seems like a PITA if you think about having to build a lot of it yourself, but most languages have some really solid OAuth 2.0 setups which you can just bolt in with varying amounts of fiddling. If you're using a framework like Laravel or RoR then it's barely any work.
PHP: http://oauth2.thephpleague.com/
Ruby (Rails or Grape): https://github.com/doorkeeper-gem/doorkeeper
If you don't want to redirect users as suggested in your post then ignore other comments and answers that talk about two legged flows. You can use the client_credentials grant type to have apps just provide their client id and secret in return for an access token, which is nice and easy.
I would ask how private are we talking, because if the only systems talking to it are within the backend and have no interaction with the outside world you could probably leave it wide open and just rely on the network to keep it safe (VPN/Firewall).
But if it's private in the sense of "our iPhone app uses it" then you definitely want to go with OAuth 2.0, or something like it.
2 legged OAuth is probably what you want to use. It's basically hashing a shared key, but you have the advantage of not having to write the code yourself.
Here's a related question: Two-legged OAuth - looking for information
You should use Oauth for mobile device to API layer communication.
However, there is no benefit of Oauth in this web UI layer to middle-layer access (machine to machine).
On the other hand there are some potential issues
Managing the access token expiry becomes a pain. Consider that your UI has to cache the access token across multiple nodes in a cluster. Refresh it when expired, and the fact that UI layer is negotiating security with backend will just take extra time once in a while.
In two legged Oauth (OAuth Client Credential as in v2.0) does not support any encryption. So you still need to send key and secret both to the server for getting an access token.
Backend has to implement issuing access token, refresh token, validating access token etc, without any significant benefit
We are starting to move our self-hosted internal services to the cloud. We've migrated some services to Google apps, but we have several application we developed ourselves that we would like to move to Heroku.
When we hosted them ourselves, authentication wasn't a problem, since being on network (physically or through VPN) was proof enough. Now that we're moving them to the big bad internet, we need some sort of login. Since all of us have google accounts, it makes sense to use them for that.
We've played with the Google OpenID option, however, this doesn't give you any information beyond the name and e-mail address, which we would then have to look up in the provisioning API, to check if that e-mail address belongs to a user we know of. That seems the wrong way to do it. Also, I'm not 100% sure that you cannot add any email address to any Google account.
I've read everything about the Google Auth APIs, but that seems to be about giving access to Google services, not our own.
So, is there a way to do Authorization (not just SSO/Authentication) with our Google Apps accounts?
If you're trying to use Google Apps as an Identity Provider, then yes, OpenID or the newer OpenID Connect support (see http://oauthssodemo.appspot.com) is the way to go.
In either case, there are other precautions you can take to make sure the email address really belongs to the user. For example, when using OpenID with Google Apps Google generally only asserts verified email addresses, and you can simply whitelist Google as a provider. If you're using the apps' version of OpenID (modified discovery protocol) then you can restrict OpenID requests to a particular domain (only make requests to that domain, an check on the response that the ID matches what was requested.)
In the case of OpenID connect, it's explicitly stated in the response whether or not it is a verified address.