How can I use the grant_type=password oauth flow with salesforce.com?
I'm trying to get an authorization token using the Username-Password flow (as described in the final section of this article).
I'm sending the following request (using Python's httplib, in case that's relevant):
https://login.salesforce.com/services/oauth2/token
POST data:
username=<un>&client_secret=<consumer_secret>&password=<pw+token>&grant_type=password&client_id=<consumer_key>
And getting the response:
400 Bad Request
{"error":"unsupported_grant_type","error_description":"grant type not supported"}
Is the password grant_type really unsupported, or am I missing something? It seems to give this error even when I'm sending a grant_type that definitely does work (such as authorization_code).
Note that I've tried the suggestions in the answer here, and they don't work for me.
Answer
Typically this is because the content-type header has not been set to the correct value, it should be application/x-www-form-urlencoded.
Also make sure your parameters are correctly encoded (especially if you're building the POST payload by hand).