How to have access to the oauth2 opaque token in the controller

Question

I have an API that uses OKTA for authentication. I need the opaque token so that I can access the OKTA APIs on behalf of the user. How can I have access to the opaque token in my controller?

Answer 1

I found this.

I created this ExchangeFilterFunction:

private ExchangeFilterFunction myExchangeFilterFunction(OAuth2AuthorizedClientService clientService) {
    return new ExchangeFilterFunction() {
        @Override
        public Mono<ClientResponse> filter(ClientRequest request, ExchangeFunction next) {
            Authentication authentication = SecurityContextHolder.getContext().getAuthentication();

            OAuth2AuthenticationToken oauthToken = (OAuth2AuthenticationToken) authentication;

            OAuth2AuthorizedClient client = clientService.loadAuthorizedClient(
                    oauthToken.getAuthorizedClientRegistrationId(),
                    oauthToken.getName());

            String accessToken = client.getAccessToken().getTokenValue();

            ClientRequest newRequest = ClientRequest.from(request)
                    .headers((headers) -> headers.setBearerAuth(accessToken))
                    .build();

            return next.exchange(newRequest);
        }
    };
}