Policy transformation error accessing http://www.ing.com/

Products

• ProxySG Software - SGOS

Issue/Introduction

When the ProxySG contains both entries below, you will receive a transformation_error exception page when you access. They are:
- a two-way URL rewrite policy that contains a "transform" action
- a policy to disable support for GZIP encoding

The Transformation Error occurred because UTF-8 is not a valid parameter for the Content-Encoding header. By design, the transformer will refuse to perform transformation if it does not understand how the content is encoded.

Resolution

Ensure the Accept-Encoding: gzip is retained in the HTTP Request by leaving the ing.com domain out from the decompress action.

An example of the CPL used to trigger the problem :

define url_rewrite BlockBadJavascript
    rewrite_script_substring '[Blocked FileSystemObject]' 'FileSystemObject'
    rewrite_script_substring '[Blocked vbscript]' 'vbscript'
    rewrite_script_substring '[Blocked WScript.Shell]' 'WScript.Shell'
    rewrite_script_substring '[Blocked Shell.Application]' 'Shell.Application'
end

define Action BlockBadJavascript_action
    transform BlockBadJavascript
end

define action ForceUncompressedResponse
    delete(request.header.Accept-Encoding)
end

<Cache>
    action.ForceUncompressedResponse(yes)

<proxy>
    action.BlockBadJavascript_action(yes)

; The following entry can also be used to replace the <Cache> layer above to trigger the problem
<Proxy>
    http.server.accept_encoding(no)

 

Solution to the example above:

<Cache>
    url.domain=!ing.com action.ForceUncompressedResponse(yes)