Citrix Systems Network Router 9.2 User Manual

Page of 302
Chapter 6        Advanced Expressions: Parsing HTTP, TCP, and UDP Data
131
Operations for HTTP, HTML, and XML Encoding and 
“Safe” Characters
The following operations work with the encoding of HTML data in a request or 
response and XML data in a POST body.
HTTP.RES.STATUS
Returns the response status code
Prefixes That Evaluate HTTP Request or Response Length
Prefix
Description
Operations That Evaluate HTML and XML Encoding
HTML or XML Operation
Description
text.HTML_XML_SAFE
Transforms special characters into XML safe 
format, as in the following examples:
• A left-pointing angle bracket (<) is converted 
to &lt; 
• A right-pointing angle bracket (>) is converted 
to &gt;
• An ampersand (&) is converted to &amp;
This operation safeguards against cross-site 
scripting attacks. This is a read-only operation.
After applying the transformation, additional 
operators that you specify in the expression are 
applied to the selected text. Following is an 
example:
http.req.url.query.html_xml_safe. 
contains("myQueryString")
text.HTTP_HEADER_SAFE
Converts all new line ('\n') characters in the input 
text to '%0A' to enable the input to be used safely 
in HTTP headers. 
This operation safeguards against response-
splitting attacks. This is a read-only operation.