Discourse OAuth2 Basic

:discourse2: Summary Discourse OAuth2 Basic supports basic OAuth2 providers, assuming they have a JSON API endpoint where user details can be retrieved by token.
:hammer_and_wrench: Repository Link https://github.com/discourse/discourse-oauth2-basic
:open_book: Install Guide How to install plugins in Discourse

Features

This plugin allows you to use a basic OAuth2 provider as authentication for Discourse. It should work with many providers, with the caveat that they must provide a JSON endpoint for retrieving information about the user you are logging in.

This is mainly useful for people who are using login providers that aren’t very popular. If you want to use Google, Facebook or Twitter, those are included out of the box and you don’t need this plugin. You can also look for other login providers in our Github Repo.

Configuration

Basic Configuration

  1. First, register your Discourse application with your OAuth2 provider. It will require a Redirect URI which will be:

    http://DISCOURSE_HOST/auth/oauth2_basic/callback

:information_source: Replace DISCOURSE_HOST with the appropriate value, and make sure you are using https if enabled. The OAuth2 provider should supply you with a client ID and secret, as well as a couple of URLs.

  1. Visit your AdminSettingsLogin and fill in the basic configuration for the OAuth2 provider:
  • oauth2_enabled - check this off to enable the feature
  • oauth2_client_id - the client ID from your provider
  • oauth2_client_secret - the client secret from your provider
  • oauth2_authorize_url - your provider’s authorization URL
  • oauth2_token_url - your provider’s token URL.

:information_source: If you can’t figure out the values for the above settings, check the developer documentation from your provider or contact their customer support.

Configuring the JSON User Endpoint

Discourse is now capable of receiving an authorization token from your OAuth2 provider. Unfortunately, Discourse requires more information to be able to complete the authentication.

We require an API endpoint that can be contacted to retrieve information about the user based on the token.

For example, the OAuth2 provider SoundCloud provides such a URL. If you have an OAuth2 token for SoundCloud, you can make a GET request to https://api.soundcloud.com/me?oauth_token=A_VALID_TOKEN and will get back a JSON object containing information on the user.

To configure this on Discourse, we need to set the value of the oauth2_user_json_url setting. In this case, we’ll input the value of:

https://api.soundcloud.com/me?oauth_token=:token

The part with :token tells Discourse that it needs to replace that value with the authorization token it received when the authentication completed.

There is one last step to complete. We need to tell Discourse what attributes are available in the JSON it received. Here’s a sample response from SoundCloud:

{
  "id": 3207,
  "permalink": "jwagener",
  "username": "Johannes Wagener",
  "uri": "https://api.soundcloud.com/users/3207",
  "permalink_url": "http://soundcloud.com/jwagener",
  "avatar_url": "http://i1.sndcdn.com/avatars-000001552142-pbw8yd-large.jpg?142a848",
  "country": "Germany",
  "full_name": "Johannes Wagener",
  "city": "Berlin"
}

The oauth2_json_user_id_path, oauth2_json_username_path, oauth2_json_name_path and oauth2_json_email_path variables should be set to point to the appropriate attributes in the JSON.

The only mandatory attribute is id - we need that so when the user logs on in the future that we can pull up the correct account. The others are great if available – they will make the signup process faster for the user as they will be pre-populated in the form.

Here’s how I configured the JSON path settings:

  oauth2_json_user_id_path: 'id'
  oauth2_json_username_path: 'permalink'
  oauth2_json_name_path: 'full_name'

I used permalink because it seems more similar to what Discourse expects for a username than the username in their JSON. Notice I omitted the email path: SoundCloud do not provide an email so the user will have to provide and verify this when they sign up the first time on Discourse.

If the properties you want from your JSON object are nested, you can use periods. So for example if the API returned a different structure like this:

{
  "user": {
    "id": 1234,
    "email": {
      "address": "test@example.com"
    }
  }
}

You could use user.id for the oauth2_json_user_id_path and user.email.address for oauth2_json_email_path.

If the key itself includes periods, you will need to put double quotes around it, or escape the periods with a backslash. For example, given this JSON:

{
  "example.com/uid": "myuid"
}

You would specify the path as example\.com/uid or "example.com/uid"

:warning: If you set oauth2_json_email_path, the OAuth2 provider must confirm the user owns that email address. Failure to do this can result in account takeover in Discourse!

:discourse2: Hosted by us? This plugin is available on our Business and Enterprise plans. OAuth 2.0 & OpenID Connect Support | Discourse - Civilized Discussion

27 Likes

5 posts were split to a new topic: What is supposed to go in “DISCOURSE_HOST”?

Love this plugin, thank you so much!

Managed to get this working with roblox beta auth 2.0:

Hello,
We are trying to integrate Discourse with our application using OAuth2 Basic but we are getting the following error in the logs:
Note: We are using NGROK as we are debugging the connection.

OAuth2 Debugging: request POST https://formshare.ngrok.io/oauth2/token

Headers: {"User-Agent"=>"Faraday v1.9.3", "Content-Type"=>"application/x-www-form-urlencoded", "Authorization"=>"Basic S2k2SFZtTVpuSTFHUExiRXVlWVJDNENiOkNvb1k0anlQemt3dWNRV21Sa2FWOVNnbHZLbjJFT3cxc3BIMmtMck9yY21vNDM4Tg=="}

Body: {"client_id"=>"Ki6HVmMZnI1GPLbEueYRC4Cb", "client_secret"=>"...some_secret_...", "grant_type"=>"authorization_code", "code"=>"5pPCrsp0pZ84373MNaHh2cuskfc8AlbfmdwMBFIVW4n4z9aX", :redirect_uri=>"https://community.formshare.org/auth/oauth2_basic/callback"}

------------------

OAuth2 Debugging: response status 200

From POST https://formshare.ngrok.io/oauth2/token

Headers: {"content-length"=>"108", "content-type"=>"text/html; charset=UTF-8", "date"=>"Thu, 01 Sep 2022 21:42:08 GMT", "ngrok-trace-id"=>"79cdc3f1c3eae5e37a30796aebbf9bd6", "server"=>"gunicorn"}

Body: {"token_type": "Bearer", "access_token": "p0FVuwjSXL1ZINEklMAVqUlpZxSll1SgnbpE8YWP4C", "expires_in": 864000}

-----------------------------------

(oauth2_basic) Authentication failure! invalid_credentials: OAuth2::Error, {"token_type": "Bearer", "access_token": "p0FVuwjSXL1ZINEklMAVqUlpZxSll1SgnbpE8YWP4C", "expires_in": 864000}

We left the params “oauth2 callback user id path” and " oauth2 callback user info paths" empty.

Any idea is appreciated.

Can I use this to authenticate with Microsofts XBL service?

I presume the logic would be similar to this?

Hi everyone. I try to configure this plugin with our internal Oauth2 server with authorization code flow.

When a user click “Connect with Oauth”, the /authorize endpoint works and a code is return to the callback. But then Discourse shows a generic 500 error " Oops. The software powering this discussion forum encountered an unexpected problem" and the /token endpoint is not accessed.

The error log says so:
OAuth2::ConnectionError (FinalDestination: all resolved IPs were disallowed) lib/final_destination/ssrf_detector.rb:74:in lookup_and_filter_ips' lib/final_destination/http.rb:13:in connect’ lib/midd

hostname discourse-app
process_id 653
application_version 702f27e6ee10ac257f5fee3f331d05f5fa5d7a45
HTTP_HOST *****
REQUEST_METHOD GET
HTTP_USER_AGENT Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/108.0.0.0 Safari/537.36
HTTP_ACCEPT text/html,application/xhtml+xml,application/xml;q=0.9,image/avif,image/webp,image/apng,/;q=0.8,application/signed-exchange;v=b3;q=0.9
HTTP_REFERER *****
HTTP_X_FORWARDED_FOR *****
HTTP_X_REAL_IP *****
time 10:25 pm
params
code def50200babf84f7376f99fefa34369d876566b6bc0a341d8fba431999a72549ac06f6aad01df6fa43061707c525ba5d725ad
state 20139e0a134a5972566d4ddb6f7f9092a2cddb9e5216973a

As I understand there is an issue with some IP address? Currently the Oauth2 server is hosted on my dev environment (localhost) and the authorize and token endpoints are configured accordingly. Is it a problem?

Found the problem:

  1. For some reason the /token endpoint was never called. After filling a maximum of options in admin parameters related to oauth the endpoint was called without answer
  2. I forgot that it was the Discourse server that would call the /token endpoint and not the webclient. Therefore, the server could not reach my localhost Oauth2 server. Putting our Oauth2 server behinf a domain solved the problem

Now, I can connect existing users but don’t undersand how to sign in new users through this plugin.
If the user sign in with oauth, it gets an error saying he has no active account on Discours server. Which is normal since it’s a new user.

Is there a dedicated callback to sign in user instead of login? Or a specific parameter to set to allow account creation?

My company oauth server was generating a /profile JSON response with a little typo in one field. Everything was okay after fixing the typo.
But I have to say that Discourse logs can be very misleading! Nothing was wrong with the callback.

Hi team,

I’m having an issue with pulling the ID I need for my user JSON request from the authorization response. In reading the documentation it appears that the account ID is sent in a nested array:

HTTP/1.1 200 OK
Content-Type: application/json;charset=UTF-8
Cache-Control: no-store
Pragma: no-cache

{
   "access_token":"2YotnFZFEjr1zCsicMWpAA",
   "token_type":"Bearer",
   "expires_in":1800,
   "refresh_token":"tGzv3JOkF0XG5Qx2TlKWIA",
   "permissions":[
      {
        "accountId":123,
        "availableScopes":["contacts_view", "contacts_me", 
"contacts_edit", "finances_view", "events_view"]
      }
   ]
}

I’ve tried setting the oauth2 callback user id path to permissions[0].accountId but my uid value is always blank. Unfortunately, calls to pull the user json require this accountId in the JSON url.

I was able to get this working by passing permissions.first.accountId, I found that when I passed permissions into a test property the array was already parsed as a Ruby array. Unfortunately, the fields seem to reject the Ruby syntax to call array elements and any attempt to use Javascript syntax would result in a TypeError String to Integer. Luckily Ruby had the syntax above, is this the intended method?

I just got this to work with Authentik OAuth2, however there were some hiccups with the oauth2 user json url setting. I used the user_info endpoint of Authentik for that (/application/o/userinfo/), however I did not know how to map the fields. For anyone looking how to set up Discourse with Authentik’s OAuth2, here’s the summary:

  • User id path: preferred_username
  • Username path: preferred_username
  • Name path: name
  • Email path: email
  • Email verified path: email_verified
  • Avatar: empty.

I had the following issues:

  1. At the beginning, I forgot the trailing slash in the json url https://DOMAIN/application/o/userinfo/. This lead to the user info request (permalink to the source) to return a 301 HTTP code, which caused the login to fail. I do not know whether the trailing slash should be there by spec, but perhaps it would be good to handle 301 correctly.
  2. Debugging this turned out tricky. The oauth2 debug auth settings was a lifesaver but… Logster truncates the debug log before actually dumping the meaningful response data. I had to modify manually in the container the log line to
    log("user_json_response: #{user_json_response.status} #{user_json_response.headers} #{user_json_response.body}")
    
    Perhaps that log line could be updated? I guess it could help other people figure out the json attributes path.
2 Likes

I just set up Auth0 with the plugin and found that avatars are not picked up.

These are the relevant settings:

  DISCOURSE_OAUTH2_ENABLED: true
  DISCOURSE_OAUTH2_CLIENT_ID: '${DISCOURSE_OAUTH2_CLIENT_ID}'
  DISCOURSE_OAUTH2_CLIENT_SECRET: '${DISCOURSE_OAUTH2_CLIENT_SECRET}'
  DISCOURSE_OAUTH2_AUTHORIZE_URL: '${DISCOURSE_OAUTH2_ISSUER}/authorize?connection=xxx&login_options=yyy'
  DISCOURSE_OAUTH2_TOKEN_URL: '${DISCOURSE_OAUTH2_ISSUER}/oauth/token'
  DISCOURSE_OAUTH2_USER_JSON_URL: '${DISCOURSE_OAUTH2_ISSUER}/userinfo'
  DISCOURSE_OAUTH2_SCOPE: 'email openid profile'
  DISCOURSE_OAUTH2_JSON_USER_ID_PATH: 'sub'
  DISCOURSE_OAUTH2_JSON_USERNAME_PATH: 'nickname'
  DISCOURSE_OAUTH2_JSON_NAME_PATH: 'name'
  DISCOURSE_OAUTH2_JSON_EMAIL_PATH: 'email'
  DISCOURSE_OAUTH2_JSON_EMAIL_VERIFIED_PATH: 'email_verified'
  DISCOURSE_OAUTH2_JSON_AVATAR_PATH: 'picture'
  DISCOURSE_OAUTH2_EMAIL_VERIFIED: true
  DISCOURSE_OAUTH2_OVERRIDES_EMAIL: true
  DISCOURSE_OAUTH2_ALLOW_ASSOCIATION_CHANGE: false

In the debug log I can see that the picture element is set in the JSON response, but the user’s avatar does not change, neither for new nor for existing users.

What did I miss?

What is the best way to replace the icon on the login button with either another icon or an image?

.btn-social.oauth2_basic:before {
    content: url('https://www.contoso.com/path/to/image');
}

.btn-social.oauth2_basic > svg {
    display: none;
}

feels sufficient but a bit hacky

2 Likes

It seems like the plugin only updates the avatar/username on initial creation of the user, not on everytime they log in.

Is there anyway to fix this and have the plugin update the avatar as well on login/reconnection?

You can use the auth overrides email, auth overrides username and auth overrides name settings to make those things apply on future logins. I’m afraid we don’t currently have a similar setting for avatars, but it would be pr-welcome

1 Like

Thank you! I actually found these later on. I forked the repo and added my own versions to get this functioning with Roblox, which included the override for avatars. Which I believe just uses DiscourseConnect avatar override so people can’t change it.

One thing I wish though is that roblox does not provide a email on OAuth so I sadly need to have them signup with a email. but thats a non issue for yall haha.

A post was split to a new topic: Twitter login doesn’t work on meta

Does anyone know if this still works?

Yes. I’m confident this plugin works. :+1:

1 Like

Hi, I was able to intergrate this plugin in my discourse discuss.frontendlead.com, I am using teachable oauth OAuth Quickstart Guide

However, I only want to allow people to be able to successfully register if and only if they have a current paid account on teachable. I would imagine, I need to add custom functionality in the plugin to handle this? I am wondering, can you guys or even I can, introduce another field on the settings called custom code after oauth, which allows developers to perform specific actions after signing up? Or if there are better suggestions, please let me know.

Edit: I forked the repo and got it working here:

If someone else using teachable is trying to do the same, my repo would work out of the box, the only thing is if you didn’t buy a course, it will say you need to go to my domain to purchase it. you may want to update that for your own usecase.

1 Like