Filtering with Quickbooks Online V2 returns 401 ErrorCode=003200, Empty body posts work perfectly - ruby

Question

We're attempting to integrate with the QuickBooks Online V2 api using Ruby 1.9.3 (not RoR).
Using the API Explorer and the Employee endpoint documentation we were able to get a simple list of test employees by using the Google Signet OAuth Gem.
require 'signet'
require 'signet/oauth_1/client'
#intialize oauth1 client
#client = Signet::OAuth1::Client.new(
:temporary_credential_uri => "https://oauth.intuit.com/oauth/v1/get_request_token",
:authorization_uri => "https://appcenter.intuit.com/Connect/Begin",
:token_credential_uri => "https://oauth.intuit.com/oauth/v1/get_access_token",
:client_credential_key => 'qyprdPEfJqU7eOze0Fby9iYhrUS5DQ',
:client_credential_secret => 'fuXsasJo4TrTEd3Yhv4TeMUizmtguh0JioIB5r2I',
:callback => "http://localhost:3000/callback/general"
)
#client.token_credential_key = 'qyprdJUtDSk7owxVfZlq7JeWO1mtpHBkSMD5GhB02PwIC6N0'
#client.token_credential_secret = 'Rq2ekgQWWL9frZAKpcgWef291mR0J5HBE354u5F3'
#setup request
original_request = [
'POST',
'https://qbo.sbfinance.intuit.com/resource/employees/v2/791630875',
# we also tried this url 'https://qbo.intuit.com/qbo28/resource/employees/v2/791630875',
[
['Content-Type', 'application/x-www-form-urlencoded'],
],
[]
]
#execute request
response = #client.fetch_protected_resource(:request => original_request)
puts response.body
As you can see the request is pretty straight-forward.
However once we create a request with a Filter in the body, we get an HTML page with the following error: HTTP Status 401 - message=Exception authenticating OAuth; errorCode=003200; statusCode=401
#setup request
original_request = [
'POST',
'https://qbo.intuit.com/qbo28/resource/employees/v2/791630875',
#'https://qbo.sbfinance.intuit.com/resource/employees/v2/791630875',
[
['Content-Type', 'application/x-www-form-urlencoded'],
],
["Filter=Name :EQUALS: Doe"]
]
We're using the Google OAuth gem, and I've verified the signature generation to be correct using these tools: LinkedIn Oauth Test Console and Beginners guide to OAuth signing requests. They both verify that the signature that Signet is generating is correct for the body I provide.
I've looked at a few SO Questions:
QuickBooks Online querying with filter returns 401 everytime
Unable to create(POST) objects (Account, customer...) on QB Windows using IDS and Sync Manager
But nothing has worked. Any help would be appreciated, we're willing to use a third party gem such as quickeebooks but we would rather not. I assume I'm just missing something simple here.
Please provide me with the following items so I can verify a working answer:
Your request parameters, including uri, header, body and exact client and access tokens (developer app tokens only please, I'll need to verify that I can generate the exact same request, including signature)
You basestring used for generating the HMAC-SHA1 signature. it will look something like
POST&https%3A%2F%2Fqbo.intuit.com%2Fqbo28%2Fresource%2Femployees%2Fv2%2F7916308‌​75&Filter%3DName%2520%253AEQUALS%253A%2520David%2520Test%26oauth_consumer_key%3Dq‌​yprdPEfJqU7eOze0Fby9iYhrUS5DQ%26oauth_nonce%3D-1787433535548338293%26oauth_signat‌​ure_method%3DHMAC-SHA1%26oauth_timestamp%3D1380089100%26oauth_token%3DqyprdJUtDSk‌​7owxVfZlq7JeWO1mtpHBkSMD5GhB02PwIC6N0%26oauth_version%3D1.0
Your response, including header and body data

Answer 1

I had tried to use filter query with employee endpoint. It works fine.
EDIT - Sharing endpoint, filter and resultset related to Employee API Endpoint
https://qbo.intuit.com/qbo28/resource/employees/v2/791926875
Filter= Name :EQUALS: Manas Mukherjee
header - "Authorization: OAuth oauth_token="2eRrd7LhEtHrM1CrqWvy1kmSgeukEgFxW99E1xwhSsLCp1JB", oauth_consumer_key="qyprdXsaKh0a132eNs7NTJLufjfrzm", oauth_version="1.0", oauth_signature_method="HMAC-SHA1", oauth_timestamp="1380084612", oauth_nonce="1556081845430558974", oauth_signature="IMjh%2FTx%2F7GMFDE6WQqZK8b6apjI%3D"[\r][\n]"
Content-Type: application/x-www-form-urlencoded
Data Set
<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<qbo:SearchResults xmlns="http://www.intuit.com/sb/cdm/v2" xmlns:qbp="http://www.intuit.com/sb/cdm/qbopayroll/v1" xmlns:qbo="http://www.intuit.com/sb/cdm/qbo">
<qbo:CdmCollections xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:type="Employees">
<Employee>
<Id idDomain="QBO">20</Id>
<SyncToken>0</SyncToken>
<MetaData>
<CreateTime>2013-09-24T21:37:22-07:00</CreateTime>
<LastUpdatedTime>2013-09-24T21:37:22-07:00</LastUpdatedTime>
</MetaData>
<Name>Manas Mukherjee</Name>
<Address>
<Line1>ABC Str</Line1>
<City>London</City>
<PostalCode>4353543</PostalCode>
<GeoCode>LAT=51.5148382,LNG=-0.1264144</GeoCode>
</Address>
<GivenName>Manas</GivenName>
<MiddleName>Kr</MiddleName>
<FamilyName>Mukherjee</FamilyName>
<ShowAs>Manas Kr Mukherjee</ShowAs>
<BillableTime>false</BillableTime>
</Employee>
</qbo:CdmCollections>
<qbo:Count>1</qbo:Count>
<qbo:CurrentPage>1</qbo:CurrentPage>
</qbo:SearchResults>
OAuth header using your tokens
"Authorization: OAuth oauth_token="qyprdJUtDSk7owxVfZlq7JeWO1mtpHBkSMD5GhB02PwIC6N0", oauth_consumer_key="qyprdPEfJqU7eOze0Fby9iYhrUS5DQ", oauth_version="1.0", oauth_signature_method="HMAC-SHA1", oauth_timestamp="1380089100", oauth_nonce="-1787433535548338293", oauth_signature="Vj67xMVhSKGjVSmGyOxt7SVv0i8%3D"[\r][\n]"
Endpoint - https://qbo.intuit.com/qbo28/resource/employees/v2/791630875
Post data to end point: Filter= Name :EQUALS: David Test
Content-Type: application/x-www-form-urlencoded
It works fine
Thanks

Answer 2

See this sample fiddler request with Filter for items in QBO. I cannot paste the fiddler log here. You can do it for similarly for Employee. The filters should go into the body and encode your header:
Request-
POST https://qbo.intuit.com/qbo1/resource/items/v2/723488155
HTTP/1.1
Content-Type: application/x-www-form-urlencoded
Authorization: OAuth oauth_token="lvprdgF9q4mSQx5A6lKNm3NISXvwIpF16z",oauth_nonce="3740352e-20a4-4d45-af4f-2b783ee20e60",oauth_consumer_key="qyprd7I5WvVnPoiBh1ejZn",oauth_signature_method="HMAC-SHA1",oauth_timestamp="1377106651",oauth_version="1.0",oauth_signature="1OAJXk5uH0sEpYpdhh%2BDMzjQFEs%3D"
Host: qbo.intuit.com
Content-Length: 28
Expect: 100-continue
PageNum=1&ResultsPerPage=100
Response Header-
HTTP/1.1 200 OK
Date: Wed, 21 Aug 2013 17:37:31 GMT
Server: Apache
Set-Cookie: qboeuid=10.129.32.5.1377106651774076; path=/; expires=Thu, 21-Aug-14 17:37:31 GMT; domain=.intuit.com
Set-Cookie: JSESSIONID=82DE11473B5246497B9FDCD8A6DA4C45.c1-pprdqboas30j; Path=/; Secure; HttpOnly
Vary: Accept-Encoding
Content-Type: application/xml;charset=UTF-8
Content-Length: 32525