Van Patten Media

Designed to be run in concert with <a href="https://wordpress.org/extend/plugins/ssl-subdomain-for-multisite/" rel="ugc">SSL Subdomain for Multisite</a>.
This plugin depends upon <a href="https://wordpress.org/extend/plugins/wordpress-mu-domain-mapping/" rel="ugc">WPMU Domain Mapping</a>, which must be installed and network activated for this to work.
<h4>What this Plugin does</h4>
If you have the <a href="https://wordpress.org/extend/plugins/ssl-subdomain-for-multisite/" rel="ugc">SSL Subdomain for Multisite</a> plugin installed and network activated, you now have logins and admin happening on <code>https://demo-site.mynetwork.com</code>, while normal site access is on <code>http://demo-site.com</code>.
This works great. Except, once you log in to <code>demo-site.mynetwork.com</code> to do some admin work, then visit the main site, perhaps to post a comment as a logged in WordPress user, you are not logged in on the main site. This means that you can’t, for example, post that comment while logged in — you aren’t logged in there! Other logged-in niceties like the display of the admin bar, or the avoidance of caching, are not available. If you log in again, it logs you in to <code>https://demo-site.mynetwork.com</code> but still you remain not logged in on <code>http://demo-site.com</code>.
This plugin solves this problem by enabling a single sign on (SSO) for both the admin panel and the main site on the custom domain. Upon login, this plugin bounces the user across to the main site to set a cookie there, then bounces them back to the admin panel.
Now, you can work in the admin panel normally, and if you click ‘Visit Site’ from the Admin panel, you go over to the custom domain, where you are also logged in and can perform all actions as normal. Single Sign On!
<h4>(Foolish) Assumptions</h4>
<ol>
<li>
You are using <a href="https://wordpress.org/extend/plugins/wordpress-mu-domain-mapping/" rel="ugc">WPMU Domain Mapping</a> for custom domains on your Multisite network.
</li>
<li>
You have SSL configured for your master domain (e.g. <code>www.mynetwork.com</code>), and for the wildcard <code>*.mynetwork.com</code>. You would like normal site access to happen over the custom domains with HTTP, and all admin and login access over the subdomains of <code>*.mynetwork.com</code> with HTTPS.
</li>
<li>
You have the <code>FORCE_SSL_LOGIN</code> setting in <code>wp-config.php</code> ON.
</li>
<li>
You have the <code>FORCE_SSL_ADMIN</code> setting in <code>wp-config.php</code> OFF. We’ll handle that — WordPress’ forcing of SSL admins may confuse this plugin.
</li>
</ol>
This plugin was tested with and is intended to be used in concert with <a href="https://wordpress.org/extend/plugins/sso-cross-cookie-for-multisite/" rel="ugc">SSL Subdomain for Multisite</a>.
<h4>Known Issues</h4>
<ul>
<li>The <code>redirect_to</code> parameter is not fully working at present. Sometimes, you will be sent to the root admin page, instead of the specific page you were trying to access. This needs to be improved, as it does compromise the user experience.</li>
<li>
This provides better security than only enabling <code>FORCE_SSL_LOGIN</code> but not <code>FORCE_SSL_ADMIN</code>, since with this plugin and <a href="https://wordpress.org/extend/plugins/sso-cross-cookie-for-multisite/" rel="ugc">SSL Subdomain for Multisite</a>, login and admin are served over HTTPS.
However, the nature of this setup means that a man-in-the-middle attacker could theoretically impersonate you for the duration of the login session. It is not possible at the moment to avoid this theoretical attack scenario without serving everything over HTTPS (making arbitrary custom domain support impossible), or preventing login to the actual custom domain site.
</li>
</ul>

SSO Cross Cookie

Single sign on (SSO) for a custom domain site, where the admin panel is on an SSL-secured subdomain. For WordPress Multisite.

DanielTulp

<h4>Major overhaul</h4>
As of version 2.0 CNP allows you to easily embed posts from other websites in the same WordPress network with a shortcode builder that is available above your editor.
The manual way of entering the shortcode is still available, but you can chooses whichever you prefer.
Also included from version 2.0 is an options page where you set certain security measures: 1. You can restrict embedding of content to only the original author of the post (does not apply to administrators) 1. You can disallow other websites in the WordPress network to embed posts from your website
<h4>Usage</h4>
This plugin is useful if you have a wordpress network (multisite) and you want to display (embed) a post or a category of posts that is on another website in the same network.
Use the shortcode builder above the editor or type the shortcode in manually:
<pre><code>[cnp blogid=1 postid=1] </code></pre>
<h4>Attributes</h4>
Mandatory
blogid is the ID of the blog you wish to pull the post from (go to Network->Sites and hover over the site to view the ID).
Instead of postid= you can also use catid= to display all posts from a category.
Optional
header=1 -> header number (i.e. h1 ), no title if you set it to 0 (default is 2)
excerpt=true -> if you only want to display excerpts with read more links to the post on the other website
numberofposts=5 -> for displaying a certain number of posts from a category (default is 5)
titlelink=false -> if you don’t want the title to have a permalink (default is true)
Working with other plugins
If you want to display a plugin through a shortcode that is in one of the posts that you are displaying, make sure that the plugin is also active on the network site where you use CNP.
Note: not all plugins will work. Post about it if you find some that do and also that don’t.

Cross-Network posts

Embed a post or a category of posts that is within another website on the same Wordpress network (multisite).

SSO Cross Cookie vs Cross-Network posts