Support for private_key_jwt and client_secret_jwt on token endpoint client ?

[gdufrene]

Hello,

it seems that configuring an oidc client with auth-method private_key_jwt or client_secret_jwt is possible, but not supported in DefaultTokenEndpointClient.

Do you confirm that there is not support for client_credentials nor authorization_code flows to token endpoints protected with such a mecanism ?

The documentation state that client_secret_basic or client_secret_post shoud be availble but no more precision about other auth method configuration.

We'd like to be able to use the jwt assertion for Oauth2 client authentication toward Authorization Server.
I was able to override this DefaultTokenEndpointClient to support such a thing but wonder why there is no support for this ?

Right now I use some really custom code, none of JwtTokenGenerator, RSASignature or SecretSignature has been used.
I suppose it should be the right way of doing so ?

No property seems to be available to inject private key for the private_key_jwt auth mecanism on OauthClientConfigurationProperties.
Any ideas to the way of configuring a private key inside the configuration ?
In my current implementation I set the client_secret as a base64 encoded jwk private key, decoding the key when sendRequest is called.