Oauth support in retrofit template

[cbornet]

Once #347 is solved, I would like to implement client oauth2 in the retrofit template.
So far I have identified the following libs:

• google oauth client: https://github.com/google/google-oauth-java-client : all types of grants
• scribe : https://github.com/fernandezpablo85/scribe-java : only authorization_code
• oltu : http://oltu.apache.org/ : only authorization_code , password and client_credential

Password and client_credential flows are very simple and do not really need to pull a lib but to support implicit grant, only google oauth seems available. So should it be the winner ?
Has anyone worked with any of those libs and has an opinion ?

[cbornet]

Edit : apparently oltu does support implicit flow

[wing328]

@cbornet scribe looks promising as it includes a lot of examples covering different OAuth providers. https://github.com/fernandezpablo85/scribe-java/tree/master/src/test/java/org/scribe/examples

Thanks in advance for you contribution to support OAuth2 in the templates.

[cbornet]

But scribe seems to only support authorization code flow whereas a swagger client should be able to use password flow. I have started using oltu and so far it is working quite well.

[wing328]

Thanks for sharing the progress. I've not looked into oltu so I can't comment on it further (their API documentation URL is broken: http://oltu.apache.org/apidocs/index.html)

[cbornet]

Indeed the project doesn't seem very lively...

[cbornet]

I have a WIP for this issue.

• The code makes use of okhttp interceptors to add the auth headers and deal with the http responses. This adds a dependency on okhttp but it seems to be the direction taken by the retrofit team (Use OkHttp as the sole client. square/retrofit#728)
• It uses the oltu library for oauth2
• It will also adds support for Basic and API key auths