Secure Extensions Distribution introduces improved security for Safari on OS X. All extensions in the Safari Extensions Gallery are now hosted and signed by Apple. Users can trust that the Safari Extension they install is the one you submitted.

Only Safari Extensions installed from the Safari Extensions Gallery can be updated automatically. Add the following two lines to each extension's dictionary entry within your Update Manifest to allow existing users to update automatically to the latest version.

The new Safari release brings Content Blocking Safari Extensions to iOS. Content Blocking gives your extensions a fast and efficient way to block cookies, images, resources, pop-ups, and other content.

Your app extension is responsible for supplying a JSON file to Safari. The JSON consists of an array of rules (triggers and actions) for blocking specified content. Safari converts the JSON to bytecode, which it applies efficiently to all resource loads without leaking information about the user’s browsing back to the app extension.

Xcode includes a Content Blocker App Extension template that contains code to send your JSON file to Safari. Just edit the JSON file in the template to provide your own triggers and actions. The sample JSON file below contains triggers and actions that block images on webkit.org.

Content Blocking is now available on OS X through Safari. Add your JSON file in the new Content Blocker section of the Safari Extensions Builder, shown in Figure 1, or use the new setContentBlocker API available on the Safari Extension object.