#64063 Remove legacy certs and update the associated Grunt commands

[johnbillion]

Trac ticket: Core-64063.

One potential concern is whether anyone is relying on the cacert.pem file to exist. For example:

wp_remote_get(
  'https://example.com',
  [
    'sslcertificates' => ABSPATH . 'wp-includes/certificates/cacert.pem',
  ]
);

[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, desrosj.

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

[Copilot]

Pull request overview

This pull request removes legacy 1024-bit SSL certificates from WordPress and simplifies the certificate bundle build process by eliminating the concatenation step that previously combined legacy certificates with the current certificate bundle.

Changes:

• Removed the legacy-1024bit.pem file containing expired 1024-bit Verisign certificates
• Removed legacy certificate headers and content from ca-bundle.crt
• Updated Grunt build tasks to copy certificates directly instead of concatenating multiple files

Reviewed changes

Copilot reviewed 3 out of 4 changed files in this pull request and generated no comments.

File	Description
src/wp-includes/certificates/legacy-1024bit.pem	Deleted file containing outdated 1024-bit certificates for backward compatibility
src/wp-includes/certificates/ca-bundle.crt	Removed prepended legacy certificates, now contains only current Mozilla CA bundle
Gruntfile.js	Updated certificate build workflow to copy directly from composer package instead of concatenating, removed obsolete file exclusions and concat task

---

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.

[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.

[johnbillion]

@desrosj I added the removed files to $_old_files. How's this looking?

[desrosj]

Thanks for this @johnbillion. Looking good with one small change.

I also noticed there's a new version of the certificates available. Do you think we can include that as part of this change with a reference to Core-64245?

Also easy enough to commit separately.

[johnbillion]

I also noticed there's a new version of the certificates available. Do you think we can include that as part of this change with a reference to Core-64245?

Thanks. Let's do that as a follow up commit just to keep things separate.

[desrosj]

Thanks! Looks good to me.