Font Library REST API: sanitize font family and font face settings

[creativecoder]

What?

Ensures font family and font face settings are sanitized when creating or updating through the REST API endpoints.

Addresses part of #58464

Why?

• Clean and normalize font family and font face settings data.
• To mitigate possible XSS attacks.

How?

• Uses the sanitize_callback param for each setting in the schema, and manually calls the callback for each property because the settings are submitted as JSON string and aren't handled by normal REST API mechanisms.
• Updates WP_Font_Utils::format_font_family to WP_Font_Utils::santize_font_family and calls sanitize_text_field on the font family value so it is sanitized in addition to being formatted.
• Manually removes arg_options from the public schema of font family and font face controllers, because the parent controller doesn't handle that for child properties.
• Add phpunit tests for the above.

Testing Instructions

• See updated unit tests.
• Try creating a font family or font face with tags, whitespace, or line breaks in the settings values and see that they are sanitized before being created.
• Check that installing from the Google Fonts collection works as expected.

[github-actions]

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Core SVN

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Props: grantmkin, youknowriad.

GitHub Merge commits

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Co-authored-by: creativecoder <grantmkin@git.wordpress.org>
Co-authored-by: youknowriad <youknowriad@git.wordpress.org>

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[github-actions]

This pull request has changed or added PHP files. Please confirm whether these changes need to be synced to WordPress Core, and therefore featured in the next release of WordPress.

If so, it is recommended to create a new Trac ticket and submit a pull request to the WordPress Core Github repository soon after this pull request is merged.

If you're unsure, you can always ask for help in the #core-editor channel in WordPress Slack.

Thank you! ❤️

View changed files

❔ lib/compat/wordpress-6.5/fonts/class-wp-font-utils.php
❔ lib/compat/wordpress-6.5/fonts/class-wp-rest-font-faces-controller.php
❔ lib/compat/wordpress-6.5/fonts/class-wp-rest-font-families-controller.php
❔ phpunit/tests/fonts/font-library/wpRestFontFacesController.php
❔ phpunit/tests/fonts/font-library/wpRestFontFamiliesController.php
❔ phpunit/tests/fonts/font-library/wpFontUtils/sanitizeFontFamily.php

[creativecoder]

This should be ready for a review.