Can only get access token for QuickBooks API once - php

Question

I'm using PHPoAuthLib in order to connect to the QuickBooks API per their example
When I follow their example, the first request that I make to the API works perfectly:
$result = json_decode($quickbooksService->request($url));
echo 'result: <pre>' . print_r($result, true) . '</pre>';
However in their example they use $_GET['oauth_token'] and $_GET['oauth_verifier'] to request an access token, and these values are only available on the $_GET server variable during the single callback from QuickBooks Online immediately after my app has been authorized.
For future requests there are no such examples on PHPoAuthLib's docs, so I tried a quick homebrew solution:
Save the response from QBO somewhere
if (!empty($_GET['oauth_token']) {
file_put_contents("token.txt", json_encode([
'oauth_token' => $_GET['oauth_token'],
'oauth_verifier' => $_GET['oauth_verifier'],
'realm_id' => $_GET['realmId']
]));
}
Use that response again later
$token = json_decode(file_get_contents("token.txt"));
$quickbooksService->requestAccessToken(
$token->oauth_token,
$token->oauth_verifier
// $token->getRequestTokenSecret() is not necessary - it will be automatically populated
);
// At this point my app crashes and return a 500 error
// Further code does not run
The error I receive is:
TokenResponseException in StreamClient.php line 68:
Failed to request resource. HTTP Code: HTTP/1.1 401 Unauthorized
Remember that the token and verifier work perfectly if I use them immediately after the app is authorized. If I save them to a file and attempt to re-use them 30 seconds later, this happens.
I think it might be a fundamental misconception about OAuth 1.0

Answer 1

I don't think what you have is a correct OAuth implementation. Have you read the OAuth spec and implemented as it's defined there?
Once you have a request token and a verifier, you use those to get an access token.
That access token is then good for 6 months.
It looks like you're trying to use a short-lived request token to continually fetch access tokens instead. That won't work.
i.e. If you're doing this everytime you want to make another request:
$quickbooksService->requestAccessToken(
Then you're doing something wrong. You should be doing that ONCE every 6 months, and that's it.
Working code here:
https://github.com/consolibyte/quickbooks-php/blob/master/QuickBooks/IPP/IntuitAnywhere.php
https://github.com/consolibyte/quickbooks-php/blob/master/QuickBooks/IPP/OAuth.php
https://github.com/consolibyte/quickbooks-php
Spec is here:
http://oauth.net/core/1.0a/#auth_step3