Google Apps Script - Server Side Authentication - google-apps-script

I would like to use GAS script as some sort of a web service. Basically, I would like to post some parameters and then using Drive service do some manipulations of Google Doc and all of this has to be done from backend, without use of browser. Now I have issue with authentication - When I deploy GAS as a Web App (Execute the app as user accessing the app, Anyone can access app), when trying to execute script via Http request, I get Google Login response (/accounts/ServiceLogin). Obviously user has to authenticate access. I was not able to find if we can apply OAtuh at that point. So my question is - What can be done to achieve this? Is there any mechanism that can be used to atuhenticate to GAS from a server side? Or am I forced to use browser with GAS?

You could have your own authentication check in the Apps Script code. You would have NO security settings with the publishing, but implement your own password check in the Apps Script code. You would set the publish "Execute the app as:" setting to ME, and the setting of "Who has access to the app:" to Anyone, even anonymous. That allows the app to be run by anyone with no authentication. Then create your own authentication by passing a password in the URL search string.
Even though putting a password in the URL search string is encrypted over a HTTPS connection, it's still considered "bad practice", because the search string could be stored in plain text in the browser history. But you aren't going to use a browser.
So, your Apps Script App would read a search string parameter from the URL, and either allow the script to be run or not. You would be implementing your own authentication system.
But you need to evaluate and decide what the security is on your server, or whatever server is sending the request. If you can send a HTTPS request to an Apps Script with a password in the URL search string, and it's not a security concern on your server, or whatever server is sending the HTTPS request, then you can consider that and make your decision.
If you want to get a response back from Apps Script to your server without anything opening up in the browser, use the Content Service:
Google Documentation - Content Service

Related

How to use OAuth 2.0 with a Google Apps Script library, with a static redirect URL?

I can't figure out how to make a shared Google Apps Script library, that uses OAuth 2.0.
The problem is that the usercallback redirect URL changes, every time I use the library in a different script. However, that means I'd need to add a new app and whitelisted redirect URL to Asana for each spreadsheet I use the script in. I'm using https://github.com/googlesamples/apps-script-oauth2.
Is there a way to always authenticate with the same redirect URL, so that the library I make can be used from any script, without registering a new redirect URL in Asana?
I'm a Developer Advocate here at Asana. If I understand your question correctly, then yes, you'll have to handle the callback separately for each script. For security reasons, we validate that the OAuth app registration registers the same url as an integration actually requests when authenticating. If this weren't true, for instance, it'd be possible to create a malicious script that uses the client_id from a legitimate script but asks for the redirect to go to its own credential-grabbing endpoint. This is fixed if the app that got the client_id on app registration also specifies precisely which endpoint should be the legal endpoint to redirect to. That means each OAuth app needs to have its own unique and consistent redirect URL :(
I suppose you could possibly create a single "router" Google Apps script which would set the state parameter with some user/script pair when hitting Asana's oauth_authorize endpoint and forward the user credentials on to the script that exists behind the router script based on that user/script pair when the response comes back, but it's not super trivial.
One final option would be to use a Personal Access Token to access Asana's API. This one token can be used by an unlimited number of scripts for access. The downside is that this token "looks like you", that is, it takes action on behalf of not a third party user but you yourself - your scripts would be an automated version of the user whose Personal Access Token they use. This can be mitigated to some extent by creating a "bot account" to access our API and giving it access inside of Asana to the projects or teams you want to gather data on. The other downside to this approach is that every script that uses the personal access token will break if you ever revoke the one token, so if that ever happens by either intent or accident, you'll have to update the Personal Access Token information in every script that uses it.
Hopefully this helps you to evaluate the options and choose which one of these options works best for your script.

How to authenticate to box-api without oauth redirecting

I am trying to make a simple integration to BOX where I only access my own account. Since this is a server-side access, (the server-process calls the Box-api), having the Oauth 2.0 redirecting is a problem.
Is there a way I could acquire a token (even manually) and use it in my code, by-passing the hassle of Oauth 2.0 and the redirection ? Or may be some other way for this kind of scenario ?
Right now you can do this with a Developer Token, but that only lasts for 1 hour.
You can also do the auth on your laptop, then put the Refresh tokens into your server in a config file, much like you might do for a database-password file (hopefully only readable by the service-account on the machine that has access to run your script).
Then build your script to take the refresh-token, go get a token pair with it, and write the new refresh token into the config file.

Authenticate Google Apps Script user via HTTP

In the scenario of scripts that need authentication to run (run as service account, locked down sharing settings, etc) is there a way to authenticate as a Google user via an HTTP tool like cURL, UrlFetchApp, or even PowerShell scripts from Windows Server environments?
You are going to have to do a little leg work on this one.
Firstly, when you publish your apps script, make sure to change the "who has access to the app" to something like "only myself".
Then you need to see what happens when you try to hit that URL from an external service without authenticating. There may be some help from the error codes you are likely to receive.
I imagine you can then use the following documents to Authenticate for Google Services IN GENERAL. Then you will most likely have to pass a sessionID or Accesskey of some sort. I only have a brief understanding of OAuth, but I do imagine that you may be able to set up a more permanent connection between your other server and your particular Google Apps Script.
I hope this helps.
Jacob

box.com api OAuth authentication

Either I'm dense, or the docs assume I already know what they're telling me, but I need some clarification on doing authentication for a box.com app. I really don't understand whate's going on. As I read it:
the app running on the user's machine sends a request to Box, including all the little secrets (Which aren't all that secret any more if the user knows how to read the code).
The user is directed to the Box login page, which then sends the user to my server (with no page specified) attaching an authentication code.
The app somehow magically gets that code back from my server and sends a request to Box for the access token.
Box sends the access token to my server?
The app again magically gets the access token from my server and sends its APT requests.
Obviously I got lost somewhere.
And, why do I have to have a server involved in the process? The article on making a JavaScript app refers to a direct request for a token. Is there documentation on that somewhere?
You register your application on Box
After registration you receive clientId and clientSecret once on Box website
You hardcode your credentials somewhere in your application
First time your application needs to access Box API it should redirect user to https://www.box.com/api/oauth2/authorize, specifying your clientId, clientSecret and redirectURI as parameters. About redirectURI see below.
The box.com website opens. User enters his own credentials in the web form on box.com
User allows your application to access his files via API on the box.com website
Box redirects user back to you application using redirectURI specified before. One of the parameters to this request is "code". This is a very short-lived (30 seconds) access code that is only aligable for obtaining real access token.
During next 30 seconds your application should make another call to Box API to next URL: https://www.box.com/api/oauth2/token, specifying the previously obtained code. If everything was correct, your application receives an access_token, a refresh_token and "expires" values.
Now your application can make requests to Box API, specifying access_token every time
access_token expires in number of seconds, specified in "expires" field. It should be about 3600 seconds or 1 hour. Each time your application sees that access_token has expired, it should make another request to Box with the refresh_token and obtain a fresh access_token for another 1 hour.
refresh_token itself expires in 14 days
Note: if you develop a desktop application, then you should open browser for user on the step 4, redirectURI should be something like http://127.0.0.1:8080/Callback and you should run a small webserver just to catch the redirect with the code as in step 7.
Box requires that you specify a redirect_uri in your application's profile, and it must be an HTTPS URL.
As a result, it is not possible to use box with what google's oauth2 documentation calls "Client Side" or "Installed" applications, only "Web Server Applications" are allowed. Web Server applications do not have the secret leaking problem, because only the server knows the secret. You can pass the access token from your server to javascript on the client after
the oauth transaction is complete, if you want the client to make api requests directly.
In your question you are not totally clear in what you are actually trying to produce.
I however suspect that you are trying to write a client application what needs to authenticate to box using the OAUTH2 solution they have delivered in API V2.
If this is for an IPhone for example BOX has a great example of how to handle it.
In a WinForm application you would need to capture the resulting code sent back by box in the browser1.isnavigating event.
Windows console application you register a custom URI registration to collect the code.
Neither of these need to be registered in the API developers Application on box as you would pass the redirect required in the request to box.
If this does not point you in the right direction and your writing a .NET app then post again and I will try to clarify a little more.
Box requires some form user interaction which is short sighted in my opinion but try a web service that simulates a user interaction which then you can save/pass the token to your application to sync up with the Box "Cloud".

Google Script OAuth for multiple users

I've created a Google App Script that handle 2 different OAuth connections.
1- Google itself to send mail on behalf of the user and access google docs (google api console used to get keys, secret)
2- gtraxapp wich is a timesheet cloud-based app. (Script is registered, got a key/secret, etc.)
The script is published as a web app. It works perfectly for my user.
When logged on a different user name, I can authorize Google OAuth without providing different key/secret, and emails will be sent from the actual user.
Problem happens with the 2nd app (gTrax).
Authorization seems to work. Running the function inside the script to authorize lead to a screen asking for permission, gtrax then appears in the account as a registered app (could revoke access if needed).
But, when running the app, I get a message saying I need permission to do this action (UrlFetchApp / simple get)
My question is :
Is this possible that I need to register each user to get a key/secret for everyone (and dealing with that in the script)...
Or do OAuth can be registered with 1 key/secret ?
In other word, are (should) key/secret linked to a single user or are they only a kind of RSA-like key pairs that, when verified, can be used to authorize any user.
My understanding is this. When you use built-in Apps Script functions, like MailApp.sendEmail, the Google Apps Script "environment" takes care for you to ask authorization for the user (1st time he access your app) and save and manage the oAuth tokens for you, so it all runs smoothly.
When you call an external service using UrlFetchApp, Apps Script oAuth authorization process works differently. The authorization is just a strange popup you get on the script editor, when you actually make the fetch call. It is not processed at "compile time" and asked before you run anything like the other services. But you also do this step only once.
The "gotcha" is that this different authorization process does not work when a user is running the app as a webapp. AFAIK it only works from the script editor itself or running directly from a spreadsheet.
If your users are just a known few, you could advise everybody to open the script editor (or a spreadsheet that contains it) and run an specific function that will just attempt the UrlFetchApp.fetch call so the popup shows up and they authorize it. Once this step is done, they can use the webapp normally. Apps Script will do the magic for you after that.
But if you plan to share this broadly, say at the Chrome Web Store, and don't want to ask every user to do this somewhat strange step, then you'll need to manage all the authorization process yourself. It means, you'll have to register your app with the third party service (if it's Google's, it's at the API Console), where you will receive a client id and a client secret. With those you'll have to place a "Authorize" submit button on your app html that will redirect the users to the 3rd party authorization url, providing the correct scope, etc. When they authorize it, the 3rd party will redirect the user back to your app providing a code token as URL parameter. You'll use this code to call the 3rd party oAuth service to get the real access and possibly refresh tokens that you'll have to use on your UrlFetch calls. You'll be responsible to save these tokens, refresh them when they expire and so on. Not a very simple procedure :-/
Oh, and although your app have only one id and secret, the tokens are per user. Which makes sense, since each call you do must be on behalf of a specific user and he *must* have authorized it.
I hope this helps.