In my CF app, I've used the CF OAuth code at riaforge to get request token and access token from QuickBooks Online and it works fine. After I tried to make a QBO API call by starting to build the http headers of the call (I followed the instructions on the section "HTTP Authorization Header" here: Implement OAuth in Your App). Then built the http header based on the methods of the code at riaforge because it worked. In addition, I've respected the order of the parameters given by Intuit in the previous link).
When I launched the API Call, I received the response: "signature_invalid"
I really want directions on how to sign the QBO online API Call with CF 9 if I have ready the 6 header parameters: