URL Processing

URL Processing was introduced in v3.7.0 as a way to customize URL processing even further and streamline the process of URL un-shortening and unwrapping that already existed.

The functionality is available from the Pipeline menu.

To understand how URL processing works, let's see how Browser Tamer processes URLs:

Every time you click on a link, it first goes via a "Pipeline" that makes optional transformations on it. This includes unwrapping Office 365 links, un-shortening URLs, and applying substitutions, all described below. Since v4.1.0 you can also run custom scripts on the URL.

Rule processor then applies rules to the URL and opens the browser based on the rule.

Un-shortening

Since v3.5.0 URL un-shortening is enabled by default due to the fact shortened URLs mask target link and make it impossible to apply a rule to it.

For instance pressing https://bit.ly/47EZHSl will actually open https://github.com/aloneguid/bt, allowing potential attackers to evade configured rules.

Browser Tamer supports the most popular URL shorteners, the list of which you can find here. If it's not in the list, fire up an issue or a PR.

Office 365 link unwrapping

Office 365 links are unwrapped for rule matching, but for security reasons wrapped URL is open. For instance,

https://eur02.safelinks.protection.outlook.com/?url=https%3A%2F%2Fwww.google.com

will apply rules to http://www.google.com but still open the original URL.

Substitutions

Substitutions works as you would expect - finds a substring in the incoming URL and replaces it with another substring.

For instance, if you want to replace google.com with bing.com, you would do the following:

Open "Substitutions" window.
Add a new substitution by clicking Add button.
Enter google.com in the Find field.
Enter bing.com in the Replace field.

For more advanced scenarios, you can use regular expressions.

To test substitutions, use the "Test" section on the top. It will show you the result of the substitution as you type in real time.

Scripts

Since v4.1.0 you can run custom scripts on the URL. This is a powerful feature that allows you to manipulate the URL in any way you want. For instance, you can add a query parameter, remove a query parameter, or even change the domain name. The possibilities are endless. Learn more about scripting.

Last modified: 21 October 2024