OAuth2 plugin: Token Introspection support

[vitorsdcs]

Token Introspection allows APIs to check the state of an OAuth2 token.

More info: https://tools.ietf.org/html/rfc7662

[subnetmarco]

@vitorsdcs you can also invoke the /oauth2_tokens endpoint on the Admin API to get a list of all the tokens on the system and their properties.

[p0pr0ck5]

This was done! :) https://getkong.org/plugins/oauth2-introspection/

[subnetmarco]

I assume this issue requested to implement the Introspection endpoint support as a new endpoint in the existing OAuth 2.0 plugin, as opposed to the linked OAuth 2.0 Introspection Endpoint plugin which leverages a third-party Introspection endpoint to authenticate requests.

If that's the case, it should be re-opened.

[p0pr0ck5]

Ah yep, I think that's the case. Faulty assumption on my part; thanks.

[NebojsaKrtolica]

...so? How's this feature development going? 😃