问题
I am trying to generate an access token from our policy but I am getting this error.
AADB2C90086: The supplied grant_type [client_credentials] is not supported.
This is a sample postman request
POST /{tenant}/oauth2/token?p=B2C_1A_SignUpOrSignInWithAAD HTTP/1.1
Host: login.microsoftonline.com
Content-Type: application/x-www-form-urlencoded
Cache-Control: no-cache
grant_type=client_credentials&client_id={client_id}&resource=https%3A%2F%2F{app_url}&client_secret={client_secret}
but it works fine if I don't use our custom policy and just go direct to the B2C tenant
POST /{tenant}/oauth2/token?api-version=1.0
... same as above
Is there something missing in our custom policy?
回答1:
B2C does not support the Client Credential Flow. Additional details are here. And here Daemons/server-side apps.
but it works fine if I don't use our custom policy
That's because you getting a token from Azure AD, not B2C.
来源：https://stackoverflow.com/questions/49757722/client-credential-gran-type-not-support-with-a-custom-b2c-policy