redirect_location_header_validator.md

Redirect Location header validator

Location header in HTTP responses are used to redirect client to different source. Most of the HTTP Redirection happens based on Location header processing. In this use case Location header is intercepted for any redirects which are to a domain that is not in a whitelist string data group. If it is not in whitelist, Location header will change to default blocked HTML page.

1. In the UI, go to Template > Groups > String Groups
2. Create a new String Group, named "whitelisted_locations_for_redirect" with the following domains.

• example.com
• example.ca
• example.org

3. Attach Stringroup to datascript below. Apply this to the "HTTP RESPONSE" Event.

-- HTTP_RESPONSE
location = avi.http.get_header("Location")
-- if redirect and location header set
if location and string.beginswith(avi.http.status(),"3") then
  location_stringgroup, match = avi.stringgroup.contains("whitelisted_locations_for_redirect", location )
  -- if location header does not contain whitelisted location, then block redirect to unknown location and redirect to default page
  if match == nil then
    avi.http.replace_header("Location", "http://www.example.com/redirect_blocked.html")
  end
end