OAuth2 Refresh Token Invalid

OAuth2 refresh token invalid

$ python -c "import requests; requests.post('https://idp.example.com/token', data={'grant_type':'refresh_token','refresh_token':'bad'})"
Traceback (most recent call last):
  ...
requests.exceptions.HTTPError: 400 Client Error: Bad Request

Why this happens

Refresh tokens expire or get revoked; wrong client_id/secret also fail.

Fix

Re-authenticate to obtain new tokens; store securely and rotate.

Wrong code

import requests
requests.post('https://idp.example.com/token', data={'grant_type':'refresh_token','refresh_token':'bad'})

Fixed code

import requests
resp = requests.post('https://idp.example.com/token', data={
    'grant_type': 'refresh_token',
    'refresh_token': 'valid'
}, timeout=10)
access = resp.json()['access_token']