Helper scripts to enable browser extensions

Mac and Edge

TL;DR:

• copy the allow.edge.ext.plist file to /Library/LaunchDaemons/ (replace <USER> with the actual user name)
• set the correct permissions with sudo chown root:wheel /Library/LaunchDaemons/allow.edge.ext.plist and sudo chmod 400 /Library/LaunchDaemons/allow.edge.ext.plist
• load the agent with sudo launchctl load /Library/LaunchDaemons/allow.edge.ext.plist

Introduction

The configuration for Microsoft Edge on Mac is located in /Library/Managed Preferences/<USER>/com.microsoft.Edge.plist. This "Propert List" file is a binary file, so you can't just edit it with a text editor. You can convert it to XML format with the plutil command, modify it with a text editor, and then convert it back to binary format.

The way how all browser extensions are blocked is by setting the ExtensionInstallBlocklist key to an item containing a wildcard * in the com.microsoft.Edge.plist file. To allow all extensions, it is necessary to remove this key from the file.

Converting the file, modifying it and converting it back is a bit cumbersome. Instead, we can leverage the tool PlistBuddy to modify the file directly without the need for convertion. To get the current values, we can issue the following command (Attention: PlistBuddy is not in the PATH, so you need to use the full path to the binary.)

# -c means command and "Print" is the command to print the content of the file
# see man PlistBuddy for more information
/usr/libexec/PlistBuddy -c "Print" /Library/Managed\ Preferences/<USER>/com.microsoft.Edge.plist

Since we are interested in the ExtensionInstallBlocklist key, we can issue the following command to get the value of the key:

/usr/libexec/PlistBuddy -c "Print :ExtensionInstallBlocklist" /Library/Managed\ Preferences/<USER>/com.microsoft.Edge.plist

which will return something like:

Array {
  *
}

To remove the key, we can issue the following command, which translates to "Set the first item of the ExtensionInstallBlocklist key to an empty string":

/usr/libexec/PlistBuddy -c "Set :ExtensionInstallBlocklist:0 ''" /Library/Managed\ Preferences/<USER>/com.microsoft.Edge.plist

For convenience, we can define an alias in the shell configuration file (e.g. ~/.bashrc or ~/.zshrc):

# requires root privileges
alias edge-allow-extensions="/usr/libexec/PlistBuddy -c 'Set :ExtensionInstallBlocklist:0 \"\"' /Library/Managed\ Preferences/<USER>/com.microsoft.Edge.plist"

Automating the process

Mac uses the launchd daemon to run tasks at specific times or when certain conditions are met. We can use a launchd agent to run the command to allow browser extensions. The "system" daemons (that are executed as root) are stored in /Library/LaunchDaemons and defined in XML files. We can create a new file, e.g. allow.edge.ext.plist (just an example) with the following content (or use the provided file in this repository):

<plist version="1.0">
<dict>
	<key>Label</key>
	<string>allow.edge.ext</string>

	<key>KeepAlive</key>
	<false/>

	<key>RunAtLoad</key>
	<true/>

	<key>ProgramArguments</key>
	<array>
		<string>/usr/libexec/PlistBuddy</string>
		<string>-c</string>
		<string>Set :ExtensionInstallBlocklist:0 ''</string>
		<string>/Library/Managed Preferences/<USER>/com.microsoft.Edge.plist</string>
	</array>

	<key>StandardErrorPath</key>
	<string>/dev/null</string>
	<key>StandardOutPath</key>
	<string>/dev/null</string>

	<key>StartInterval</key>
	<integer>30</integer>
</dict>
</plist>

This file will run the command every 30 seconds. This is necessary, because the configuration of Microsoft Edge is overwritten some time after the reboot through some scripts and we don't have a real trigger / event to react on that change. (If you know a better way, please let me know!) Property List files for LaunchDaemons must be owned by root and have permissions set to 600 or 400 according to Apple's documentation. We can issue the following commands to set the correct permissions:

sudo chown root:wheel /Library/LaunchDaemons/allow.edge.ext.plist
sudo chmod 400 /Library/LaunchDaemons/allow.edge.ext.plist

To load the daemon, we can issue the following command:

sudo launchctl load /Library/LaunchDaemons/allow.edge.ext.plist

Next time the Mac is restarted, the agent will be loaded automatically. To unload the agent, we can issue the following command:

sudo launchctl unload /Library/LaunchDaemons/allow.edge.ext.plist