Authorization: Bearer <xxx> is not supported

[stepancheg]

Hello,

I'm reading the library,

https://docs.rs/oci-client/0.14.0/oci_client/secrets/enum.RegistryAuth.html

pub enum RegistryAuth {
    Anonymous,
    Basic([String](https://doc.rust-lang.org/nightly/alloc/string/struct.String.html), [String](https://doc.rust-lang.org/nightly/alloc/string/struct.String.html)),
}

There's no option to authenticate with token, for example, with a token returned from gcloud auth print-access-token, which is, to my understanding, is meant to be sent as Authorization: Bearer <xxx> header.

[thomastaylor312]

Honestly I've always been a bit confused with this myself. This wouldn't be too hard to add mind you, but I'm not sure what the expected standard is. I've used Google container registry and it requires a password even with a token: https://cloud.google.com/artifact-registry/docs/docker/authentication#token. Most registries I've used (ghcr, GCR, ACR, ECR, Docker Hub) all have required a username along with a token. @flavio do you know if there is standard behavior here or not? It looks like ORAS supports plain Bearer token: https://github.com/oras-project/oras-go/blob/05a2b09cbf2eab1df691411884dc4df741ec56ab/registry/remote/auth/client.go#L193