I'm using the GTMOAuth-2 library to implement an OAuth 2 Authorization Code Grant flow to the Asana API, but consistently getting back a server error 500. The GTMHTTPFetcher log is as follows (selectively redacted):
fetch tokens for app.asana.com
2013-05-08 16:46:58 +0000
Request: POST https://app.asana.com/-/oauth_authorize
Request headers:
Content-Type: application/x-www-form-urlencoded
User-Agent: gtm-oauth2 <user-agent>
Request body: (199 bytes)
client_id=<client-id>&client_secret=_snip_&code=<client-secret>&grant_type=authorization_code&redirect_uri=http%3A%2F%2Fwww.google.com%2FOAuthCallback
Response: status 500
Response headers:
Cache-Control: no-store
Content-Length: 303
Content-Type: text/html; charset=UTF-8
Date: Wed, 08 May 2013 16:46:56 GMT
Pragma: no-cache
Server: nginx
Set-Cookie: <cookie>
X-Asana-Content-String-Length: 303
X-Asana-Preferred-Release-Revision: 20130508_073846_310cafc985fd5fb43121784b58d5dcd2503ffffe
Response body: (303 bytes)
<html>
<head>
<title>Error</title><script>__FILE__="(none)";var config = {
"CLUSTER": "prod",
"PRETTY_JS_CODEGEN": false,
"ENABLED_FEATURES": ""
};</script><link rel="shortcut icon" href="/-/static/luna/browser/images/favicon.ico" />
</head>
<body>
<h3>Error</h3><pre>Server Error</pre>
</body>
</html>
I've double-checked the auth and token URLs, client ID and secret, made sure the redirect URIs match on Asana and in-app. Interestingly, the authorization flow seems to get as far as authorizing the app (and the Asana site records the app as authorized), but it then never seems to return the authorization token. Is there anywhere I might be going wrong, or is this truly an internal server error?
(I work at Asana). I'm unsure where in the flow this request is being made, but it doesn't look correct. Once you've obtained the authorization code (by having the user interact with the Asana form), the library should then make a request to our /-/oauth_token endpoint, and pass us the code. So it's possible that you just need to be using the /-/oauth_token endpoint instead of the /-/oauth_authorize endpoint as you're doing.
If you look at our OAuth examples you'll note that there are two different URLs, one for authorization and one for token exchange.
Asana is probably returning a 500 because it's not expecting this and we're not doing a good enough job catching the problem.