fix: allow non-enterprise, saml users to complete registration in authn MFEFix: Redirect non-enterprise SAML to authn MFE

[angonz]

Description

PR #27431 included a condition that was ment to prevent enterprise users with tpa-hint enabled and coming from SAML IdP to be redirected to the authn MFE, as it "doesn't support a co-branded login/register screen with the enterprise customer (e.g., enterprise logo, custom messaging, etc.)."

However the condition also prevented non-enterprise, SAML users to be redirected to the authn MFE.

Supporting information

It was discussed in a slack conversation.

Testing instructions

To test this use case:

• Do not use enterprise
• Configure and enable SAML authentication
• Make sure that in the Django admin, Third-party authentication › Provider Configuration, "Skip registration form" is unchecked
• Register via the IdP
• Verify that you are redirected to the authn MFE to complete the registration form.

Tests run as part of PR #27431 should also pass:
Enterprise customer with tpa-hint and SAML IdP should be redirected to the legacy registration page.

Deadline

ASAP.

Other information

We happen to have a client that requested SAML authentication, and a number of customizations in the authn MFE including custom fields. Users are then redirected to the legacy register page, which is based on Backbone. These pages are not theme-able, so porting the customizations is extremely complex and not scalable.

[openedx-webhooks]

Thanks for the pull request, @angonz!

What's next?

Please work through the following steps to get your changes ready for engineering review:

🔘 Get product approval

If you haven't already, check this list to see if your contribution needs to go through the product review process.

• If it does, you'll need to submit a product proposal for your contribution, and have it reviewed by the Product Working Group.
  • This process (including the steps you'll need to take) is documented here.
• If it doesn't, simply proceed with the next step.

🔘 Provide context

To help your reviewers and other members of the community understand the purpose and larger context of your changes, feel free to add as much of the following information to the PR description as you can:

• Dependencies

  This PR must be merged before / after / at the same time as ...

• Blockers

  This PR is waiting for OEP-1234 to be accepted.

• Timeline information

  This PR must be merged by XX date because ...

• Partner information

  This is for a course on edx.org.

• Supporting documentation
• Relevant Open edX discussion forum threads

🔘 Get a green build

If one or more checks are failing, continue working on your changes until this is no longer the case and your build turns green.

🔘 Let us know that your PR is ready for review:

Who will review my changes?

This repository is currently maintained by @openedx/wg-maintenance-edx-platform. Tag them in a comment and let them know that your changes are ready for review.

Where can I find more information?

If you'd like to get more details on all aspects of the review process for open source pull requests (OSPRs), check out the following resources:

• Overview of Review Process for Community Contributions
• Pull Request Status Guide
• Making changes to your pull request

When can I expect my changes to be merged?

Our goal is to get community contributions seen and reviewed as efficiently as possible.

However, the amount of time that it takes to review and merge a PR can vary significantly based on factors such as:

• The size and impact of the changes that it introduces
• The need for product review
• Maintenance status of the parent repository

💡 As a result it may take up to several weeks or months to complete a review and merge your PR.