Support Resource Owner Password Credentials grant

[jgrandja]

We need to provide support for the Resource Owner Password Credentials Grant.

This issue is divided into the following tasks.

Servlet

• #31 Add password OAuth2AccessTokenResponseClient
• #32 Implement password OAuth2AuthorizedClientProvider

Reactive

• #102 Add password ReactiveOAuth2AccessTokenResponseClient
• #103 Implement password ReactiveOAuth2AuthorizedClientProvider

[alwyn]

@jgrandja have you got any ideas on how you plan to implement this?

I am in need of this (in the client) and looking at coding it, but I'm new to framework internals and oauth2, so currently I'm just following breadcrumbs and maybe naively basing it on client credentials.

[jgrandja]

Thanks for reaching out @alwyn. This feature will be implemented in ServletOAuth2AuthorizedClientExchangeFilterFunction and ServerOAuth2AuthorizedClientExchangeFilterFunction. However, depending on the outcome of the re-factoring exercise in #6811 , it may be implemented in a separate ExchangeFilterFunction. I plan on working on #6811 this coming week and after that is merged than we can start looking at implementing Resource Owner Password Grant feature. As an FYI, this will definitely get into 5.2.