Modify Headers

An add-on for Firefox by Gareth Hunt. Help on using the add-on is available at http://www.garethhunt.com/modifyheaders/help/

Modifications

1. Support for replacement based on a regular expression match. If the Header value for a Modify action is of the form {regex}{replacement} regex is a Regular expression replacement is the string a matched header portion will be replaced with. A known limitation since the above pattern must be wrapped in forward slashes, is that you can't use forward slashes in your regex or replacement string.

2. If a Host header is being modified using the regex pattern, the whole request is replaced. The replaced channel (nsIHttpChannel) has a modified URL (nsIStandarURL). This feature utilizes code from the https-everywhere addon (IOUtil.js). As an example, using the Header value "{www.domain.com}{192.168.254.65}" Will make all the requests from a page to that domain go to the IP address. So a linked CSS on the index page etc - www.domain.com/css/style.css would be requested as 192.168.254.65/css/style.css Use case example: A firewall blocking access to www.domain.com but not to it's IP.