Complete apache auth (SAML/SSO) flow with redirect page

[mrow4a]

Description

Without this change, server-side redirect to default page for Apache Auth (e.g. Shibboleth) resulted in session data missing on client side. Flow was incomplete and was missing final redirect page on client side to correctly handle redirect_url and persist the session data on the client.

Related Issue

• Fixes https://github.com/owncloud/enterprise/issues/5225
• Fixes https://github.com/owncloud/enterprise/issues/4712
• Related Core should check apache auth #31054

How Has This Been Tested?

• manually in internal oc2.lab test instance

Types of changes

• Bug fix (non-breaking change which fixes an issue)

Checklist:

• Base code changes
• Make sure to handle corner cases in login
• Unit tests added
• Acceptance tests added
• Changelog item, see TEMPLATE

[update-docs]

Thanks for opening this pull request! The maintainers of this repository would appreciate it if you would create a changelog item based on your changes.

[mrow4a]

I did not add acceptance tests as part of this PR, as these need to be in the apps handling the backend, in here we can only cover with unit tests

[mmattel]

@d7oc maybe of interest for you

[mrow4a]

@janackermann @DeepDiver1975 could you have a look here? target for this is oc10.11

[mmattel]

I just made a small doc fix, unhide to see details.

[ownclouders]

💥 Acceptance tests pipeline apiWebdavPreviews-mariadb10.2-php7.4 failed. The build has been cancelled.

https://drone.owncloud.com/owncloud/core/36296/97

[DeepDiver1975]

As discussed offline - as long as this works 👍

[mmattel]

@phil-davis I just added a comment text fix which resulted in Build was killed ... any CI hickup?

[phil-davis]

@phil-davis I just added a comment text fix which resulted in Build was killed ... any CI hickup?

This PR was quite a lot of commits behind master. I rebased just now - let's see if CI is happier.

[phil-davis]

https://drone.owncloud.com/owncloud/core/36296/97/14
apiWebdavPreviews/previews.feature:210

That is failing in master today - issue owncloud/QA#750 - it is being looked at...

[sonarqubecloud]

Kudos, SonarCloud Quality Gate passed!   

0 Bugs
0 Vulnerabilities
0 Security Hotspots
0 Code Smells

75.0% Coverage
0.0% Duplication

[sonarqubecloud]

Kudos, SonarCloud Quality Gate passed!   

0 Bugs
0 Vulnerabilities
0 Security Hotspots
0 Code Smells

75.0% Coverage
0.0% Duplication

[mrow4a]

@phil-davis btw, as mentioned in https://github.com/owncloud/enterprise/issues/5225#issuecomment-1167075255 and https://github.com/owncloud/enterprise/issues/5225#issuecomment-1166973577, as there is no acceptance test in user_shibolleth , we would need to make sure all works with SAML/SSO enabled in QA env.