#21022 Switch to using base64 encoding in wp_fast_hash() so its return value remains below 60 characters in length

[johnbillion]

Trac ticket: https://core.trac.wordpress.org/ticket/21022

[github-actions]

The following accounts have interacted with this PR and/or linked issues. I will continue to update these lists as activity occurs. You can also manually ask me to refresh this list by adding the props-bot label.

Core Committers: Use this line as a base for the props when committing in SVN:

Props johnbillion, peterwilsoncc, krupajnanda.

To understand the WordPress project's expectations around crediting contributors, please review the Contributor Attribution page in the Core Handbook.

[github-actions]

Test using WordPress Playground

The changes in this pull request can previewed and tested using a WordPress Playground instance.

WordPress Playground is an experimental project that creates a full WordPress instance entirely within the browser.

Some things to be aware of

• The Plugin and Theme Directories cannot be accessed within Playground.
• All changes will be lost when closing a tab with a Playground instance.
• All changes will be lost when refreshing the page.
• A fresh instance is created each time the link below is clicked.
• Every time this pull request is updated, a new ZIP file containing all changes is created. If changes are not reflected in the Playground instance,
  it's possible that the most recent build failed, or has not completed. Check the list of workflow runs to be sure.

For more details about these limitations and more, check out the Limitations page in the WordPress Playground documentation.

Test this pull request with WordPress Playground.

[peterwilsoncc]

Change request inline to improve accuracy of the test for the issue identified.

[johnbillion]

Ok I've added new tests. This change isn't actaully sufficient, because the resulting <timestamp>:<hash> value for user_activation_key is still 63 characters in length when the old schema has a limit of 60.

[kjnanda]

@johnbillion This issue is part of WordPress 6.8 release and I wanted to check with you if we are on track for the same?

[johnbillion]

@kjnanda Yes 21022 is on track for 6.8 and already has commits. This PR covers some follow-up adjustments. Thanks!

[peterwilsoncc]

This looks good to me.

While manually testing, I changed the constant to include padding, ie SODIUM_BASE64_VARIANT_URLSAFE, to make sure it was under the required length. It was.

I also confirmed that a hash length of 31 characters failed the new tests leaving 30 as the maximum possible length.

[github-actions]

A commit was made that fixes the Trac ticket referenced in the description of this pull request.

SVN changeset: 59904
GitHub commit: b5e0c16

This PR will be closed, but please confirm the accuracy of this and reopen if there is more work to be done.