We were calling `parse_remote_to_hash` in the Devise initializer, which
runs when the application starts.
That meant that, if we got an exception when calling that method, the
application wouldn't start. We got exceptions if the single sign-on
(SSO) URL isn't available or we aren't providing the right credentials.
So we're moving the call to `parse_remote_to_hash` to
`OmniauthTenantSetup`, which is only called when actually trying to sign
in with SAML.
Since we're moving the code there, we're also unifying the code so SAML
settings are configured the same way for the main tenant and other
tenants, like we did for OpenID Connect in commit c3b523290.
In order to keep the existing behavior, we're caching the result of
`parse_remote_to_hash` in an instance variable. Not sure about the
advantages and disadvantages of doing so over parsing the remote URL
metadata on every SAML-related request.
Note that the SAML tests in `OmniauthTenantSetup` use the `stub_secrets`
method. But this method is called after the application has started,
meaning it doesn't stub calls to `Rails.application.secrets` in
`config/initializers/`. So, before this commit, the code that parsed the
IDP metadata URL wasn't executed in the tests. Since now we've moved the
code but we don't want to depend on external URLs when running the
tests, we need to stub the call to the external URL. Since we're now
stubbing the call, we're adding expectations in the tests to check that
we correctly use the settings returned in that call.
The `issuer` setting was renamed to `sp_entity_id` in omniauth-saml [1],
and it's been deprecated in ruby-saml since version 1.11.0, released on
July 24, 2019 [2].
The ruby-saml code currently uses:
```
def sp_entity_id
@sp_entity_id || @issuer
end
```
So setting `issuer` to the same value as `sp_entity_id` if
`sp_entity_id` is present, as we were doing, has no effect.
On the other hand, neither omniauth-saml nor ruby-saml use the
`idp_metadata_url` and `idp_metadata` settings.
[1] https://github.com/omniauth/omniauth-saml/commit/74ed8dfb3aed
[2] https://github.com/SAML-Toolkits/ruby-saml/releases/tag/v1.11.0
When we first added OIDC support, we were configuring the redirect URI
in the devise initializer, just like we did for other providers.
Thanks to the changes in the previous commit, that code is no longer in
the devise initializer, which means we can use `url_helpers` to get the
redirect URI.
This means we no longer need to define this URI in the secrets. This is
particularly useful for multitenancy; previously, we had to define the
redirect URI for every tenant because different tenants use different
domains or different subdomains.
We were following the same pattern as we used for other providers like
twitter or facebook, but for OIDC we aren't passing the key and the
secret as separate attributes but only a hash of options. This means we
don't need to duplicate the same logic in the devise initializer and the
`OmniauthTenantSetup` class.
Thanks to these changes, we'll be able to introduce dynamic redirect
URLs for both the default tenant and the other tenants (see next commit).
Note that we could probably apply similar changes for the SAML provider.
We might do so in the future. For other providers, removing the
references to `Rails.application.secrets` broke their configuration when
we tested it back in 2022 as part of the multitenancy feature. We might
check whether that's no longer the case (or whether we made a mistake
during our tests in 2022) in the future.
We were using the `client_options` hash for the default tenant, defined
in the Devise initializer, but we forgot to include that key in the
multitenant code. This means OIDC wasn't working when different tenants
used different configurations.
- name: :oidc → Identifier for this login provider in the app.
- scope: [:openid, :email, :profile] → Tells the provider we want the user’s ID (openid), their email, and basic profile info (name, picture, etc.).
- response_type: :code → Uses Authorization Code Flow, which is more secure because tokens are not exposed in the URL.
- issuer: Rails.application.secrets.oidc_issuer → The base URL of the OIDC provider (e.g., Auth0). Used to find its config.
- discovery: true → Automatically fetches the provider’s endpoints from its discovery document instead of manually setting them.
- client_auth_method: :basic → Sends client ID and secret using HTTP Basic Auth when exchanging the code for tokens.
Add system tests for OIDC Auth
Edit the oauth docs to support OIDC auth
The purpose of the lib folder is to have code that doesn't necessary
belong in the application but can be shared with other applications.
However, we don't have other applications and, if we did, the way to
share code between them would be using a gem or even a git submodule.
So having both the `app/` and the `lib/` folders is confusing IMHO, and
it causes unnecessary problems with autoloading.
So we're moving the `lib/` folder to `app/lib/`. Originally, some of
these files were in the `app/services/` folder and then they were moved
to the `lib/` folder. We're using `app/lib/` instead of `app/services/`
so the upgrade is less confusing.
There's an exception, though. The `OmniAuth::Strategies::Wordpress`
class needs to be available in the Devise initializer. Since this is an
initializer and trying to autoload a class here will be problematic when
switching to Zeitwerk, we'll keep the `require` clause on top of the
Devise initializer in order to load the file and so it will be loaded
even if it isn't in the autoload paths anymore.
