I have a google cloud function in Java.
Client will invoke the function using HTTP trigger URL.
But that is not secure. I have gone through some docs saying that you should pass a token or client ID and then verify it in server side.
Can anyone explain that in detail and please provide a code example if any.
My doubt is to authenticate the client while they invoke the function using Http trigger
This page explains quite well all the capacity that you have to authenticate a requester on Cloud Functions.
If you have users, the best way is to use Firebase Auth (our Google Cloud Identity Platform which is simply a more advance solution than Firebase Auth with more features)
However, you need to grant all you user with cloudfunction.invoker role, to allow them to invoke the Cloud Functions. It could be difficult. You can also perform the check on your side, but in this case you remove the security (filter) layer of google and you have to check all the traffic by yourselves (not really safe, in term of billing and in case of attack).
The latest solution, API keys, is not recommended, especially for the users. But for machine to machine it's sometime the only solution. However, there isn't out of the box solution and for this I wrote an article, that explains how to create a Cloud Endpoint (or now a Cloud API Gateway which is the serverless solution of Cloud Endpoint with ESPv2) to accept API Keys.
With this latest solution, if you change your security definition, you can also accept OAuth2 tokens coming from Firebase Auth (or Cloud Identity Platform), but this time, you don't need to grant all the users on your Cloud Functions IAM role. The token only need to be valid and it's the Cloud Endpoint service account which is used to perform the call (and thus which needs to be authorized on the Cloud Functions).
In addition, because you can accept OAuth2 token, you can also accept non Google token, and thus have your users in any IDP OAuth2 compliant (KeyCloak, Okta,...)
You could use external OAuth server like keycloack (https://github.com/keycloak/keycloak), or use somethging like Json Web Tokens -- https://jwt.io/ -- available for various languages, siutable for microservices.
Related
I want to use "Http Request Headers" to connect to BigQuery without using Urlfetchapp.
I want to authenticate my service account with the BigQuery-specific library that AppsScript provides.
I want to rewrite this code to accept headers(without using Urlfetchapp)
BigQuery.Jobs.query({
query: " SOME QUERY; " ,
useLegacySql: false
}, projectID);
This page has the specs, but I couldn't figure it out.
https://developers.google.com/apps-script/guides/services/advanced#how_method_signatures_are_determined
Unfortunately, that's not possible. Both the built-in and advanced services in Google Apps Script leverage user-specific account credentials. There is no way to modify those services to use a service account.
To use service accounts, you'll need to generate those credentials yourself (JSON Web Token keys) and use them to create access tokens to authorize your queries against the BigQuery API (via UrlFetchApp.fetch()).
However, Eric Koleda's OAuth2 library does support the two-legged OAuth flow required by service accounts and therefore removes the tedium of implementing it for yourself.
Here's a link to the documentation on how to use set-up a two-legged OAuth flow for service accounts using that library:
Using Service Accounts
That should be enough to get you moving in the right direction.
URLfetchapp is used to issue HTTP and HTTPS request and response headers, so to connect BigQuery with GAS with request headers, URLFetchApp has to be used using URLFetchApp.fetch method as mentioned in the documentation.
Moreover for authenticating the service accounts, you can use OAuth2 for Apps Scripts which uses access tokens for authorization. You can check the setup process in this link. For using OAuth2 with a service account, you need to create a service account and also need to create a JWT(JSON Web Token). You can request an access token from Google which can be used to make API calls. For more information, you can check this documentation.
I have a Google Cloud Function. I also have a web application. I want to authenticate requests to the cloud function by using a service account.
I have the json key file.
I know that I have to follow https://cloud.google.com/functions/docs/securing/authenticating#service-to-function. But that is leading me to an IAP page that does not apply to google cloud functions.
Another similar instructions are found in https://developers.google.com/identity/protocols/oauth2/service-account
But if I am following the python library code, I end up with the sample code there :
import googleapiclient.discovery
sqladmin = googleapiclient.discovery.build('sqladmin', 'v1beta3', credentials=credentials)
response = sqladmin.instances().list(project='exciting-example-123').execute()
This does not directly relate to invoking a cloud function.
This question's answer somewhat deals with my requirement but is using a Call API which is only suitable for testing.
Also, I want to expose this API to multiple applications using another tech like .net. So I believe the best option for me will be to use the HTTP method (given on the same page):
https://developers.google.com/identity/protocols/oauth2/service-account#httprest
But whatever I do I am unable to get the signature right.
Any help to get this sorted will be highly appreciated as I am stuck on this for the past few days.
You can use the Google auth library like this
from google.oauth2.id_token import fetch_id_token
from google.auth.transport import requests
audience="my_audience"
r = requests.Request()
token=fetch_id_token(r,audience)
print(token)
The fetch_id_token method will use the default credentials
The service account key file defined in the environment variable GOOGLE_APPLICATION_CREDENTIALS
The service account loaded in the Google Cloud environment
For now, I followed this answer in PHP
In the claims section, I removed the scope. Instead added a claim of target_audience.
"target_audience" => "google-function-http-trigger"
the cloud function http trigger will look like https://us-central1-test-project-name.cloudfunctions.net/function-name",
This will give the required assertion key.
Then I follow https://developers.google.com/identity/protocols/oauth2/service-account#httprest to get the id_token
Then with the id_token as the bearer token we can call the cloud function.
please note that the token expires depending on the time set in the "exp" claim. Once expired you have to redo the steps to generate the new id_token
I want to authenticate requests to the cloud function by using a service account.
I am not sure I understand the context correctly, but I would try to assign a roles/cloudfunctions.invoker IAM role to that service account (which is used to run your code in the web application) - see Cloud Functions IAM Roles .
In that case a code under that service account "Can invoke an HTTP function using its public URL"
I reckon no json keys are required in this case.
I am new to google cloud functions and try to restrict access to my function by only requests from dialogflow webhooks. I see two options in gcloud console: allow unauthenticated requests and restrict by user accounts. I don't understand how to implement that authentication. Dialogflow webhooks has options to set http headers that sets in webhook requests. But gcloud console hasn't interface/options to obtain any data that I can write as http authentication header. So I see only option implement authetication flow in cloud function, but in that way why google added option to restrict access by http authentication. Can anyone give me an example step-by-step example how to obtain http headers names and data needed to implement http authentication on cloud functions from dialogflow webhooks?
There isn't built in authentication, you have to perform it by yourselves. You have some guidance here in the Google Cloud Documentation
In summary, set your function public (allow unauthenticated) and perform the check in your code.
Here's what I'm trying to do:
Remotely execute a Google Apps Script function from an online automation service (Zoho Flow, similar in purpose to Zapier.)*
This function that I am remotely executing is to add gmail labels to everyone in an organization.
In order to do this, I've done the following:
Created a service account with domain-wide-delegation in the same GCP project associated with the function that adds gmail labels.
Used the OAuth2 library for Google Apps Script to perpetuate JWT authorization for that service account in my script.
Verified that function works with service account functionality for all users in a Google oragnization within google apps script
Deployed this script as an API Executable to enable remote execution
Created authtokens authorized with the mail scope for the Apps Script API (https://mail.google.com/), as well as an additional scope required by the OAuth2 library in my script. This is done in the google developer playground, using OAuth2.0 Client ID credentials that are authorized as a part of that same GCP project.
Successfully executed the function remotely using the Google Apps Script API with Postman
Now, in order to actually make this functionality official, I now have to replace postman and the google developer console with the actual client, which is this Zoho Flow platform for api connections and process automation.
In order to make the switch I've done the following;
Added the authorized redirect URl for the client (Zoho Flow) under the same credentials that are used for the Google Developer Playground:
Utilized the credentials found from the JSON representation of those credentials** for creating what's called a "connection" in this software, which is basically an easy-to-use OAuth2.0 connection with a nice front-end that can be used for accessing API data (this is the part where I create this connection):
Entered the same scope for this connection that were authorized in the google developer playground, as well as that additional scope (https://www.googleapis.com/auth/script.external_request) that the OAuth2.0 library for Google Apps Script uses:
Lo and behold, I get the error below when attempting to gain access to Google API data from a web application, and the scopes that are said to cause the error is every scope except for the mail scope: https://mail.google.com/. I've done additional testing to verify that every other scope that is a part of the google apps script API also create this error, not just this external scope for the OAuth2 library.
Support said it was likely an issue with my credential permissions; is my line of logic for this correct? If it is, then it is an issue with their software that I will have them pursue further.
Some additional testing has been done on the software (Zoho Flow) to confirm whether or not it is a software error or not: I'm not certain if the process defined in my answer is best practices, or even 100% correct (other users can speak to it,) but I've confirmed that the error I am seeing is likely an error with the client.
Here's why:
When authorizing for multiple scopes, I get the error seen at the end of my question:
When changing that connection to utilize only one of my scopes instead, like so:
The connection proceeds properly, and I can remotely execute functions that utilize only that one scope successfully. This does work for any one scope that I authorize. The only problem is, it's a rare occurrence that a script only requires one scope. While this I can get around this major bug, I cannot remotely execute my function that adds gmail labels to all users in an organization because it requires two scopes. This will be mentioned to the development team and it should be fixed soon.
I've wrote a tiny script that retrieves publicly available data from some APIs, in JSON format. I'm now trying to get some protected data out from bit.ly (click stats from a given user) and so I obviously need to authenticate via OAuth.
I don't seem to understand the role of client id and secret, as well as the user API key. I also don't get how to grab an access token (maybe generated during OAuth authentication?) to authenticate my HTTP requests of protected data. Do you guys know any good (e)book, article or any other resources I should read to understand in detail these architectural nuances of authenticated data retrievals and HTTP requests?
It is exactly as you suspect. The access token is granted during the OAuth process, which is basically a three step rocket of getting
Temporary credentials for your application
An end user needs to authenticate those temporary credentials, which grants you a verifier token
And finally you exchange your temporary credentials and the user verification for an access token.
Depending on which language/framework you are using, there are often good libaries available to help you implement an OAuth client. Check out: http://oauth.net/code/
But you will be well served by a clear understanding of how the whole thing works. Twitter has a great tutorial about OAuth 1: https://dev.twitter.com/docs/auth/oauth.
Regarding OAuth 2. Check out http://hueniverse.com/2010/05/introducing-oauth-2-0/. Hueniverse is a good resource for all things OAuth by the way.