I am having trouble getting an access token for the Quickbooks API. I successfully get a request token and user verification, but when I run this code:
$ch = curl_init();
curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
curl_setopt($ch, CURLOPT_URL, 'https://oauth.intuit.com/oauth/v1/get_access_token?oauth_consumer_key=qyprdNDNZ9hEhZgwZBBia6ZDkwpRtP&oauth_nonce=HUPXw&oauth_signature=raVWgofhFJpAtES9e0mqlxe0I2k%3D&oauth_signature_method=HMAC-SHA1&oauth_timestamp=1384812231&oauth_token=qyprdWLEO99zeQjkz3C75A6bJxLYMgOESy9PQDS4IIUZ9fY3&oauth_verifier=7unnxvg&oauth_version=1.0');
$r = curl_exec($ch);
print $r;
... it prints "oauth_problem=signature_invalid". What am I doing wrong?