Quickbook online service gives 500 internal server - php

Question

I am trying to call service via curl and here is my code and every time I got the attached error
error_reporting(-1);
$qbsite = "https://qbo.sbfinance.intuit.com/resource/account/v2/960432556";
$headers = array(
'Content-Type'=>'application/xml',
'oauth_version' => "1.0",
'oauth_signature_method'=>"HMAC-SHA1",
'oauth_nonce'=>"xxx",
'oauth_timestamp'=>"xxx",
'oauth_consumer_key'=>"qyprdvZraQrBVbrPIptwd6gl6C6knP",
'oauth_token'=>"qyprdyLcCq9KMGVzqxtObeOkTvSWhhi7sNSW62u9gwqDXsc7",
'oauth_signature'=>"LnVYSgE9YZ77KgKZ1kLT3ouIu1M=",
);
$xmlData = '<?xml version="1.0" encoding="utf-16"?>
<Account xmlns:ns2="http://www.intuit.com/sb/cdm/qbo" xmlns="http://www.intuit.com/sb/cdm/v2">
<Name>Loan Account </Name>
<Desc>Loan Account</Desc>
<Subtype>Savings</Subtype>
<AcctNum>5001</AcctNum>
<OpeningBalanceDate>2010-05-14</OpeningBalanceDate>
</Account>';
$ch = curl_init($qbsite);
curl_setopt ($ch, CURLOPT_SSL_VERIFYPEER, FALSE);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
curl_setopt($ch, CURLOPT_POST, 1);
curl_setopt($ch, CURLOPT_HTTPHEADER, $headers);
curl_setopt($ch, CURLOPT_POSTFIELDS, "\n{$xmlData}");
$response = curl_exec($ch);
print($response);die; !

Answer 1

This:
$headers = array(
'Content-Type'=>'application/xml',
'oauth_version' => "1.0",
'oauth_signature_method'=>"HMAC-SHA1",
'oauth_nonce'=>"xxx",
'oauth_timestamp'=>"xxx",
'oauth_consumer_key'=>"qyprdvZraQrBVbrPIptwd6gl6C6knP",
'oauth_token'=>"qyprdyLcCq9KMGVzqxtObeOkTvSWhhi7sNSW62u9gwqDXsc7",
'oauth_signature'=>"LnVYSgE9YZ77KgKZ1kLT3ouIu1M=",
);
Is not even close to a correct OAuth signature. OAuth signatures place all of that information in a single Authorization: ... HTTP header, whereas you've slapped each piece of OAuth data in a separate HTTP header.
For example, a correct OAuth header looks something like this:
Authorization: OAuth realm="",
oauth_consumer_key="dpf43f3p2l4k3l03",
oauth_nonce="kllo9940pd9333jh",
oauth_timestamp="1191242096",
oauth_signature_method="HMAC-SHA1",
oauth_version="1.0",
oauth_signature="tR3%2BTy81lMeYAr%2FFid0kMTYa%2FWM%3D"
Additionally, OAuth signatures are not static values - they must be calculated and they change with EVERY request.
You should download the nightly build of the QuickBooks PHP DevKit (disclaimer: I'm the author) - it's a library that is specifically designed to do exactly what you're doing (integrate with QuickBooks), and it takes care of building the correct OAuth requests for you.
Specifically, download it and look at these examples:
docs/example_ipp_oauth.php
docs/example_ipp_ids_5.php

Answer 2

Have you tried removing the , at the end of this line
'oauth_signature'=>"LnVYSgE9YZ77KgKZ1kLT3ouIu1M=",