[OAUTH-WG] Usage of Password Grant

[Beena Santhosh <[e-mail]>]

Hi,


We have a product with client server architecture where our server manages
thousands of devices. Each device has a client-piece that talks to the
server over SOAP/REST. The client currently uses a HTTP Basic
Authentication (unique id and a secret string) for all the calls. The
secret string is created when the device enrolls to the server. It is
available at the server as well as stored securely on the device. For the
rest calls it is the device that is getting authenticated.



 Sending the credentials every time is less than ideal and we want to move
to some tokenized device authentication. We evaluated OpendID Connect based
on the general recommendation of SSO solution, but the issue is we do not
have any user interaction and hence there is no Grant flow that is fitting.
Hence we evaluated OAuth grant type of which we found Password Grant and
Client Credentials Grant is matching our requirement.



 In order to use Client Credentials in our use case, we need to do dynamic
registration for the thousands of devices managed by the server, if IoT
comes into picture the number is going to be even higher, which is highly
cumbersome to manage.  Also, as per  RFC7591 on dynamic client
registration, using access token for registering client is optional too.
Even though the Password grant is highly discouraged by the spec, we found
it to be highly matching with our requirements.



But as per the Oauth 2.1 proposal, password grant is going to be removed. Can
you suggest the way forward for us? I believe we are not a one-off case.


Thank You,

Beena