Sharepoint 2013 : Security and Policy - Granting Permissions (part 3) - Anonymous Access

By default, SharePoint requires users to authenticate before gaining access to a site collection. In some cases, the organization may have a desire to open a site to anonymous users. Anonymous users are those users who visit a SharePoint site without ever authenticating—as far as SharePoint is concerned, there is no user information or user context for the user accessing the site collection anonymously. Typically, anonymous user access does not make a whole lot of sense for team sites and intranet-like site collections, but it makes perfect sense when used in conjunction with publishing web sites in SharePoint.

Anonymous access begins with the web application, which ties configuration to the application in Internet Information Server (IIS). If an administrator does not enable anonymous access at the creation of the web application, or later in the web application settings, then SharePoint does not allow anonymous access at the site collection level.  The following steps detail how to enable anonymous access for an existing web application:

1. Open Central Administration.
2. Click the Manage Web Applications option under the Application Management heading.
3. Select the desired web application from the list.
4. Click the Authentication Providers icon on the ribbon.
5. SharePoint shows a dialog containing configured zones for the web application (Figure 4).

   

   Figure 4. Authentication Providers for a web application

6. Click the title of the zone to change the authorization and enable anonymous access (typically Default).
7. In the dialog that appears, check the check box in the Anonymous Access section.
8. Scroll to the bottom of the dialog and click the Save button. (Note: you may notice a slight delay before the dialog closes.)

You should now have enabled anonymous access for the web application. However, you must now also enable anonymous access at the site collection. The following steps demonstrate how to achieve this:

1. Open the site collection of the site to enable anonymous access.
2. Click the gear icon and then select the Site Settings menu option.
3. Click the link for site permissions, under the Users and Permissions heading.
4. Click the Anonymous Access icon on the ribbon (this icon grayed out if anonymous access not enabled at the web application level).

Figure 5 shows the options for anonymous access:

• Entire Web Site—Anonymous users see everything in read mode.
• Lists and Libraries—Anonymous users can only see lists and list items where the owner has explicitly granted permissions to anonymous users.
• Nothing—No anonymous access to the site collection.

  

  Figure 5. Anonymous Access permissions

The Client Object Permission Requirement ensures that anonymous users cannot interact with your site collection without the Remote Interfaces permission. This is important—without this option checked, anonymous users can write script via the Client Object Model to interact with your site collection. This is not to say that secure content in the site collection is available to anonymous users—the Client Object Model respects security—but leaving this option checked provides another layer of protection.