HTTP Post Using httplib2 Error

Question

I am trying to get a new access token by using a refresh token as described by Google here. Google says I need to make a HTTP request. I had no clue how to do that, so I looked up how to do it from here. However, I must be doing the post incorrectly because I get an invalid_request error.

Below is my relevant code:

h = Http()
post_data = {'POST': '/o/oauth2/token HTTP/1.1', 
             'HOST:': 'accounts.google.com', 
             'Content-Type:': 'application/x-www-form-urlencoded',
             'client_id':ClientID,
             'client_secret':ClientSecret,
             'refresh_token':SavedRefreshToken,
             'grant_type':'refresh_token'}
resp, content = h.request("https://accounts.google.com/o/oauth2/token", 
                          "POST", 
                          urlencode(post_data))

And the response I get is:

{
  "error" : "invalid_request"
}

What am I missing here?

Answer 1

It's really just that you are sending 'Content-type' in the body when it should be sent in headers. Additionally, you don't need 'POST': '/o/oauth2/token HTTP/1.1' and 'HOST:': 'accounts.google.com' in your body. Try doing this:

h = Http()
post_data = {'client_id':ClientID,
             'client_secret':ClientSecret,
             'refresh_token':SavedRefreshToken,
             'grant_type':'refresh_token'}

headers = {'Content-type': 'application/x-www-form-urlencoded'}

resp, content = h.request("https://accounts.google.com/o/oauth2/token", 
                          "POST", 
                          urlencode(post_data),
                          headers=headers)

print content

It should print something like:

{
  "access_token" : "ya29.AHBS6ZCtS8mBc_vEC9FFBkW2x3ipa7FLOs-Hi-3UhVkpacOm",
  "token_type" : "Bearer",
  "expires_in" : 3600
}