✨feat: add base64 encoded email protection

[welpo]

TL;DR

Introduced a feature to protect email addresses from spambots using base64 encoding. Emails can be added in plain text or pre-encoded to prevent scraping, especially from public repos. Decoding occurs client-side via JavaScript.

Description

This PR introduces a feature that protects email addresses from spambots by optionally allowing them to be base64 encoded, either to hide them from potential scraping in public repos or for in-site protection.

The email addresses are then decoded on the client side using ~400 bytes of JavaScript, ensuring genuine users see the actual email, while offering a level of protection against spambots that don't execute JavaScript.

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Key features

1. Flexible configuration in TOML:

   • Users can add their email in plain text.
   • Alternatively, users can pre-encode their email in base64, which is especially useful to prevent scraping from public repositories.
   • Provides an option (encode_plaintext_email) to encode the plaintext email on the website.

2. JavaScript decoding:

   • A decoding function is triggered on page load to populate the actual email link.
   • Supports decoding non-ascii characters, accommodating internationalised email addresses (reference) like pelé@example.com or медведь@с-балалайкой.рф.
   • If JavaScript is disabled, the email remains hidden.

3. Tera temple integration:

   • The templating engine processes the email configuration and determines whether to present the encoded or actual email.
   • Checks the validity of a base64 encoded email to ensure it decodes to a valid email address.

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Changes made

1. Updated TOML configuration:

   • Added email and encode_plaintext_email configuration options to handle emails, along with comments explaining the features.

2. Added JavaScript decoder:

   • New file: decodeMail.min.js (and decodeMail.js, for reference) which contains functions to decode base64 emails and update the href of email links.

3. Enhancements in Tera template:

   • Updated the footer.html template to incorporate the encoded email functionality.
   • Conditionally load the JavaScript decoding function based on email encoding needs.

4. Documentation:

   • The post explaining JavaScript-dependent features has been updated to reflect this new feature (in all 3 languages).

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How to use

• E-mail decoding for spambot protection: If you wish to guard your email against spambots scraping from your website, simply set the configuration encode_plaintext_email = true. You can set the email variable to your actual e-mail, unless…

• Public repository protection: For those who have their sites on public repositories and wish for an additional layer of security, it's recommended to pre-encode your email into a base64 string before adding it to the configuration. This ensures that even if spambots scrape the repository, they won't get the plain-text email.

To encode your email in base64, you can use online tools or run from your terminal: printf 'mail@example.com' | base64.

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Inspiration

This idea is based off (or copied, at least the concept) the Abridge theme.