As asked in the subject, can you advise when there is a need to re-send the request for a new Refresh Token before the previous one is expired? The post states that Access Token is expired in 5 mins but doesn't mention that of Refresh Token.
A few points of clarification.
There are two types of credential a user may use to access RDP APIs + data
A username is designed for display type usage only (e.g. for testing with the RDP API Playground) and will therefore expire within 18hrs and only allow a single connection at a time. It must not be used for programmatic access to RDP data.
A MachineID is for programmatic access to RDP data and a correctly configured one should never expire under normal circumstances and it should also allow 5 concurrent connections.
If a MachineID is expiring on a regular basis then this means the MachineID was incorrectly configured and needs to be recreated.
Having said all the above, a MachineID may occasionally expire due to various exceptional circumstances. Therefore, a robust application should be coded defensively to handle this possibility. Both the above techniques that myself and my colleague Gurpreet mention should be included in a robust application i.e. using a password grant login to obtain a new Refresh token when:
I hope this clarifies the position on Refresh Token expiry
Whilst I cannot confirm how long a Refresh Token lasts, the various RDP Websocket API examples (Python, C# and Java) demonstrate that when you are trying to get a new Access Token; if you get error 400 or 401 - but you already have an existing RefreshToken - then you should log in again using username and password etc to get new Refresh Token
e.g. Python snippet:
def get_sts_token(current_refresh_token, url=None): ....
elif r.status_code == 400 or r.status_code == 401: # Retry with username and password print('EDP-GW authentication HTTP code:', r.status_code, r.reason) if current_refresh_token: # Refresh token may have expired. Try using our password. print('Retry with username and password') return get_sts_token(None)
where r is the response from the requests.post call
Any developer writing an application that uses OAuth2 with Refresh and Access tokens should implement the above functionality - rather than hardcoding any particular value for getting a new Refresh Token
The refresh tokens typically last 18 hours.
When your application detects that the expires_in key in the Refresh Grant response is not equal to the original expires_in key, this implies that your refresh token has expired and the application should use Password Grant to continue.