pas.plugins.oidc 1.0.0

An add-on for Plone

pas.plugins.oidc

This is a Plone authentication plugin for OpenID Connect. OAuth 2.0 should work as well because OpenID Connect is built on top of this protocol.

Features

• PAS plugin, although currently no interfaces are activated.

• Three browser views for this PAS plugin, which are the main interaction with the outside world.

Installation

Install pas.plugins.oidc by adding it to your buildout:

[buildout]

...

eggs =
    pas.plugins.oidc

and then running bin/buildout

Warning

Pay attention to the customization of User info property used as userid field, with the wrong configuration it’s easy to impersonate another user.

Install and configure the plugin

• Go to the Add-ons control panel and install pas.plugins.oidc.

• In the ZMI go to the plugin properties at http://localhost:8080/Plone/acl_users/oidc/manage_propertiesForm

• Configure the properties with the data obtained from your provider:

  • OIDC/Oauth2 Issuer

  • Client ID

  • Client secret

  • redirect_uris: this needs to match the public URL where the user will be redirected after the login flow is completed. It needs to include the /Plone/acl_users/oidc/callback part. When using Volto you need to expose Plone somehow to have the login process finish correctly.

  • Use Zope session data manager: see the section below about the usage of session.

  • Create user / update user properties: when selected the user data in Plone will be updated with the data coming from the OIDC provider.

  • Create authentication __ac ticket: when selected the user will be allowed to act as a logged-in user in Plone.

  • Create authentication auth_token (Volto/REST API) ticket: when selected the user will be allowed to act as a logged-in user in the Volto frontend.

  • Open ID scopes to request to the server: information requested to the OIDC provider. Leave it as it is or modify it according to your provider’s information.

  • Use PKCE: when enabled uses PKCE when requesting authentication from the provider.

---

Login and Logout URLs

When using this plugin with Plone 6 Classic UI the standard URLs used for login (http://localhost:8080/Plone/login) and logout (http://localhost:8080/Plone/logout) will not trigger the usage of the plugin.

When using this plugin with a Volto frontend the standard URLs for login (http://localhost:3000/login) and logout (http://localhost:3000/logout) will not trigger the usage of the plugin.

To login into a site using the OIDC provider, you will need to change those login URLs to the following:

• Login URL: /<Plone Site Id>/acl_users/<oidc pas plugin id>/login

• Logout URL: /<Plone Site Id>/acl_users/<oidc pas plugin id>/logout

  Where:

  • Plone Site Id: is the id you gave to the Plone site when you created it. It is usually Plone but may vary. It is the last part of the URL when you browse Plone directly without using any proxy server, ex. http://localhost:8080/Plone+ -> Plone.

  • oidc pas plugin id: is the id you gave to the OIDC plugin when you created it inside the Plone PAS administration panel. If you just used the default configuration and installed this plugin using Plone’s Add-on Control Panel, this id will be oidc.

When using Volto as a frontend, you need to expose those login and logout URLs somehow to make the login and logout process work.

---

Example setup with Keycloak

Setup Keycloak as server

Please refer to the Keycloak documentation for up to date instructions. Specifically, here we will use a Docker image, so follow the instructions on how to get started with Keycloak on Docker. This does not give you a production setup, but it is fine for local development.

Note: Keycloak runs on port 8080 by default. Plone uses the same port. When you are reading this, you probably know how to let Plone use a different port. So let’s indeed let Keycloak use its preferred port. At the moment of writing, this is how you start a Keycloak container:

docker run -p 8080:8080 -e KEYCLOAK_ADMIN=admin -e KEYCLOAK_ADMIN_PASSWORD=admin quay.io/keycloak/keycloak:19.0.3 start-dev

The plugin can be used with legacy (deprecated) Keycloak redirect_uri parameter. To use this you need to enable the option in the plugin configuration. To test that you can run the Keycloak server with the --spi-login-protocol-openid-connect-legacy-logout-redirect-uri=true option:

docker run -p 8080:8080 -e KEYCLOAK_ADMIN=admin -e KEYCLOAK_ADMIN_PASSWORD=admin quay.io/keycloak/keycloak:19.0.3 start-dev --spi-login-protocol-openid-connect-legacy-logout-redirect-uri=true

Note: when you exit this container, it still exists and you can restart it so you don’t lose your configuration. With docker ps -a figure out the name of the container and then use docker container start -ai <name>.

Follow the Keycloak Docker documentation further:

• Open the Keycloak Admin Console, make sure you are logged in as admin.

• Click the word master in the top-left corner, then click Create Realm.

• Enter plone in the Realm name field.

• Click Create.

• Click the word master in the top-left corner, then click plone.

• Click Manage -> Users in the left-hand menu.

• Click Create new user.

• Remember to set a password for this user in the Credentials tab.

• Open a different browser and check that you can login to Keycloak Account Console with this user.

In the original browser, follow the steps for securing your first app. But we will be using different settings for Plone. And when last I checked, the actual UI differed from the documentation. So:

• Open the Keycloak Admin Console, make sure you are logged in as admin.

• Click the word master in the top-left corner, then click plone.

• Click Manage -> Clients in the left-hand menu.

• Click Create client:

  • Client type: OpenID Connect

  • Client ID: plone

  • Turn Always display in console to On, Useful for testing.

  • Click Next and click Save.

• Now you can fill in the Settings -> Access settings. We will assume Plone runs on port 8081:

  • Root URL: http://localhost:8081/Plone/

  • Home URL: http://localhost:8081/Plone/

  • Valid redirect URIs: http://localhost:8081/Plone*

    Tip: Leave the rest at the defaults, unless you know what you are doing.

• Now you can fill in the Settings -> Capability config.

  • Turn Client authentication to On. This defines the type of the OIDC client. When it’s ON, the OIDC type is set to confidential access type. When it’s OFF, it is set to public access type.

  • Click Save.

• Now you can access Credentials -> Client secret and click on the clipboard icon to copy it. This will be necessary to configure the plugin in Plone.

Keycloak is ready done configured!

---

Setup Plone as a client

• In your Zope instance configuration, make sure Plone runs on port 8081.

• Make sure pas.plugins.oidc is installed with pip or Buildout.

• Start Plone and create a Plone site with id Plone.

• In the Add-ons control panel, install pas.plugins.oidc.

• In the ZMI go to the plugin properties at http://localhost:8081/Plone/acl_users/oidc/manage_propertiesForm

• Set these properties:

  • OIDC/Oauth2 Issuer: http://localhost:8080/realms/plone/

  • Client ID: plone

    Warning: This property must match the Client ID you have set in Keycloak.

  • Client secret: ••••••••••••••••••••••••••••••••

    Warning: This property must match the Client secret you have get in Keycloak.

  • Use deprecated redirect_uri for logout url(/Plone/acl_users/oidc/logout) checked. Use this if you need to run old versions of Keycloak.

  • Open ID scopes to request to the server: this depends on which version of Keycloak you are using, and which scopes are available there. In recent Keycloak versions, you must include openid as scope. Suggestion is to use openid and profile.

  • Tip: Leave the rest at the defaults, unless you know what you are doing.

  • Click Save.

Plone is ready done configured!

See this screenshot:

Warning:

Attention, before Keycloak 18, the parameter for logout was redirect_uri and it has been deprecated since version 18. But the Keycloak server can run with the redirect_uri if needed, it is possible to use the plugin with the legacy redirect_uri parameter enabled also. The problem is that if the deprecated parameter is enabled in the plugin but not in the server, the plugin will not work.

So, this is the way it works:

• With legacy redirect_uri parameter enabled in Keycloak, the plugin works in default mode.

• With legacy redirect_uri parameter enabled in Keycloak, the plugin also works with legacy mode.

• With legacy redirect_uri parameter disabled in Keycloak (default after version 18), the plugin works in default mode.

• With legacy redirect_uri parameter disabled in Keycloak (default after version 18), the plugin does NOT work with legacy mode.

So, for Keycloak, it does not matter if we use the default or legacy mode if the Keycloak runs in legacy mode.

Notes:

• If legacy redirect_uri parameter is disabled in Keycloak, this is the default since version 18 of Keycloak according to this comment in Starck Overflow: https://stackoverflow.com/a/72142887.

• The plugin will work only if the Use deprecated redirect_uri for logout url(/Plone/acl_users/oidc/logout) option is un-checked at the plugin properties at http://localhost:8081/Plone/acl_users/oidc/manage_propertiesForm.

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Login

Go to the other browser, or logout as admin from Keycloak Admin Console. Currently, the Plone login form is unchanged.

Instead, for testing go to the login page of the plugin: http://localhost:8081/Plone/acl_users/oidc/login, this will take you to Keycloak to login, and then return. You should now be logged in to Plone, and see the full name and email, if you have set this in Keycloak.

Logout

If the login did work as expected you can try to Plone logout. Currently, the Plone logout form is unchanged.

Instead, for testing go to the logout page of the plugin: http://localhost:8081/Plone/acl_users/oidc/logout, this will take you to Keycloak to logout, and then return to the post-logout redirect URL.

---

Usage of sessions in the login process

This plugin uses sessions during the login process to identify the user while he goes to the OIDC provider and comes back from there.

The plugin has 2 ways of working with sessions:

• Use the Zope Session Management: if the Use Zope session data manager option in the plugin configuration is enabled, the plugin will use the sessioning configuration configured in Zope. To do so we advise using Products.mcdutils to save the session data in a memcached based storage. Otherwise Zope will try to use ZODB based sessioning which has shown several problems in the past.

• Use the cookie-based session management: if the Use Zope session data manager option in the plugin configuration is disabled, the plugin will use a Cookie to save that information in the client’s browser.

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Settings in environment variables

Optionally, instead of editing your OIDC provider settings through the ZMI, you can use collective.regenv and provide a YAML file with your settings. This is very useful if you have different settings in different environments and you do not want to edit the settings each time you move the contents.

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Varnish

Optionally, if you are using the Varnish caching server in front of Plone, you may see this plugin only partially working. Especially the came_from parameter may be ignored. This is because the buildout standard configuration from plone.recipe.varnish removes most cookies to improve anonymous caching.

The solution is to make sure the __ac_session cookie is added to the cookie-pass option. Check what the current default is in the buildout recipe, and update it:

[varnish-configuration]
recipe = plone.recipe.varnish:configuration
...
cookie-pass = "auth_token|__ac(|_(name|password|persistent|session))=":"\.(js|css|kss)$"

---

Contribute

• Issue Tracker: https://github.com/collective/pas.plugins.oidc/issues

• Source Code: https://github.com/collective/pas.plugins.oidc

• Documentation: https://docs.plone.org/foo/bar

References

• Blog post: https://www.codesyntax.com/en/blog/log-in-in-plone-using-your-google-workspace-account

License

The project is licensed under the GPLv2.

Contributors

• mamico, [e-mail]

• erral, Mikel Larreategi

• alecghica, [e-mail]

• macagua, [e-mail]

Changelog

1.0.0 (2023-11-11)

• Allow dict instances to hold userinfo [erral]

1.0a6 (2023-07-20)

• Added Spanish translation [macagua]

• Added improvements about i18n support [macagua]

• Drop python 2.7 and Plone 4 support [erral]

• Add support for the post_logout parameter for logout api. [ramiroluz]

1.0a5 (2023-04-05)

• Catch exceptions during the OAuth process [erral]

• Update the plugin to make challenges. An anonymous user who visits a page for which you have to be authenticated, is redirected to the new require_login view on the plugin. This works the same way as the standard require_login page of Plone. [maurits]

• Add a property for the default userinfo instead of using only sub. [eikichi18]

1.0a4 (2023-01-16)

• Call getProperty only once when getting redirect_uris or scope. [maurits]

• use getProperty accessor [mamico]

1.0a3 (2022-10-30)

• Removed the hardcoded auth cookie name [alecghica]

• Fixed Python compatibility with version >= 3.6 [alecghica]

• check if url is in portal before redirect #2 [erral]

• manage came_from [mamico]

1.0a2 (unreleased)

• do userinforequest if there is a client.userinfo_endpoint [mamico]

1.0a1 (unreleased)

• Initial release. [mamico]