Please note this page doesn't pretend to be a step-by-step guide.
This piece of documentation will try to give you some hints to move your current MITREid instance to Hydra.
Scopes in hydra doesn't have a relational entity, every client defines its own array of scopes.
Since hydra uses scp as the scope claim, you have to be sure your client libraries are capable to use both, we had to modify the behavior of our version of spring.security.oauth2 library following the example: Custom claim
MITREid doesn't mind if the parameters are passed in the body or in the query string. In order to work with hydra, you have to migrate all your calls that are using QS params to Body Parameters.
For example, you should move from
curl -X POST http://127.0.0.1/mitreid-server/token?grant_type=client_credentials -H "Authorization: $AUTH" ...
curl -X POST http://127.0.0.1/mitreid-server/token -H "Authorization: $AUTH" --data-urlencode 'grant_type=client_credentials' ...
The last pitfall found during the migration was the difference of behaviour when
client_credentials grant without specifying a scope. By default
ORY Hydra returns an empty scope, but MITREid grants the default scope for the
OAuth 2.0 Client.
To change the behaviour in ORY Hydra, either set environment variable
OAUTH2_CLIENT_CREDENTIALS_DEFAULT_GRANT_SCOPE=true or alternatively add to ORY
Hydra's configuration file:
oauth2: client_credentials: default_grant_allowed_scope: true
Once set, ORY Hydra will behave like MITREid and grant the OAuth2 Client's scope
when an empty scope is requested for a