F5 Networks iRule/Tcl - Escaping UNICODE 6-character escape sequences so they are processed as and r
- by openid.malcolmgin.com
We are trying to get an F5 BIG-IP LTM iRule working properly with SharePoint 2007 in an SSL termination role. This architecture offloads all of the SSL processing to the F5 and the F5 forwards interactive requests/responses to the SharePoint front end servers via HTTP only (over a secure network).
For the purposes of this discussion, iRules are parsed by a Tcl interpretation engine on the F5 Networks BIG-IP device.
As such, the F5 does two things to traffic passing through it:
Redirects any request to port 80 (HTTP) to port 443 (HTTPS) through HTTP 302 redirects and URL rewriting.
Rewrites any response to the browser to selectively rewrite URLs embedded within the HTML so that they go to port 443 (HTTPS). This prevents the 302 redirects from breaking DHTML generated by SharePoint.
We've got part 1 working fine.
The main problem with part 2 is that in the response rewrite because of XML namespaces and other similar issues, not ALL matches for "http:" can be changed to "https:". Some have to remain "http:". Additionally, some of the "http:" URLs are difficult in that they live in SharePoint-generated JavaScript and their slashes (i.e. "/") are actually represented in the HTML by the UNICODE 6-character string, "\u002f".
For example, in the case of these tricky ones, the literal string in the outgoing HTML is:
http:\u002f\u002fservername.company.com\u002f
And should be changed to:
https:\u002f\u002fservername.company.com\u002f
Currently we can't even figure out how to get a match in a search/replace expression on these UNICODE sequence string literals. It seems that no matter how we slice it, the Tcl interpreter is interpreting the "\u002f" string into the "/" translation before it does anything else.
We've tried various combinations of Tcl escaping methods we know about (mainly double-quotes and using an extra "\" to escape the "\" in the UNICODE string) but are looking for more methods, preferably ones that work.
Does anyone have any ideas or any pointers to where we can effectively self-educate about this?
Thanks very much in advance.
