Add Reactive Messaging AuthenticationPrincipalArgumentResolver

[rwinch]

Summary

We should be able to use an argument resolver for the RSocket Support in Spring

[nofelkad]

Adding @AuthenticationPrincipal to messageMapping method gives

java.lang.NullPointerException
	at io.rsocket.util.ByteBufPayload.sliceData(ByteBufPayload.java:149)
	Suppressed: reactor.core.publisher.FluxOnAssembly$OnAssemblyException: 
Assembly trace from producer [reactor.core.publisher.FluxMapFuseable] :
	reactor.core.publisher.Flux.map(Flux.java:5892)
	org.springframework.messaging.rsocket.annotation.support.MessagingRSocket.handleAndReply(MessagingRSocket.java:170)
Error has been observed at the following site(s):
	|_            Flux.map ⇢ at org.springframework.messaging.rsocket.annotation.support.MessagingRSocket.handleAndReply(MessagingRSocket.java:170)
	|_  Flux.doOnSubscribe ⇢ at org.springframework.messaging.rsocket.annotation.support.MessagingRSocket.handleAndReply(MessagingRSocket.java:170)
	|_            Flux.map ⇢ at org.springframework.messaging.handler.annotation.reactive.PayloadMethodArgumentResolver.extractContent(PayloadMethodArgumentResolver.java:178)
	|_           Flux.next ⇢ at org.springframework.messaging.handler.annotation.reactive.PayloadMethodArgumentResolver.decodeContent(PayloadMethodArgumentResolver.java:247)
	|_            Mono.map ⇢ at org.springframework.messaging.handler.annotation.reactive.PayloadMethodArgumentResolver.decodeContent(PayloadMethodArgumentResolver.java:248)
	|_          Mono.error ⇢ at org.springframework.messaging.handler.annotation.reactive.PayloadMethodArgumentResolver.lambda$decodeContent$5(PayloadMethodArgumentResolver.java:249)
	|_  Mono.onErrorResume ⇢ at org.springframework.messaging.handler.annotation.reactive.PayloadMethodArgumentResolver.decodeContent(PayloadMethodArgumentResolver.java:249)
	|_  Mono.switchIfEmpty ⇢ at org.springframework.messaging.handler.annotation.reactive.PayloadMethodArgumentResolver.decodeContent(PayloadMethodArgumentResolver.java:251)
	|_ Mono.defaultIfEmpty ⇢ at org.springframework.messaging.handler.invocation.reactive.InvocableHandlerMethod.getMethodArgumentValues(InvocableHandlerMethod.java:184)
	|_      Mono.doOnError ⇢ at org.springframework.messaging.handler.invocation.reactive.InvocableHandlerMethod.getMethodArgumentValues(InvocableHandlerMethod.java:185)
	|_            Mono.zip ⇢ at org.springframework.messaging.handler.invocation.reactive.InvocableHandlerMethod.getMethodArgumentValues(InvocableHandlerMethod.java:192)
	|_        Mono.flatMap ⇢ at org.springframework.messaging.handler.invocation.reactive.InvocableHandlerMethod.invoke(InvocableHandlerMethod.java:128)
	|_  Mono.switchIfEmpty ⇢ at org.springframework.messaging.handler.invocation.reactive.InvocableHelper.handleMessage(InvocableHelper.java:195)
	|_        Mono.flatMap ⇢ at org.springframework.messaging.handler.invocation.reactive.InvocableHelper.handleMessage(InvocableHelper.java:196)
	|_          Mono.error ⇢ at org.springframework.messaging.handler.invocation.reactive.InvocableHelper.lambda$handleMessage$4(InvocableHelper.java:200)
	|_  Mono.onErrorResume ⇢ at org.springframework.messaging.handler.invocation.reactive.InvocableHelper.handleMessage(InvocableHelper.java:197)
	|_          Mono.defer ⇢ at org.springframework.messaging.rsocket.annotation.support.MessagingRSocket.handleAndReply(MessagingRSocket.java:173)
	|_      Mono.doFinally ⇢ at org.springframework.messaging.rsocket.annotation.support.MessagingRSocket.handleAndReply(MessagingRSocket.java:174)
	|_       Mono.thenMany ⇢ at org.springframework.messaging.rsocket.annotation.support.MessagingRSocket.handleAndReply(MessagingRSocket.java:180)
	|_       Mono.thenMany ⇢ at org.springframework.messaging.rsocket.annotation.support.MessagingRSocket.handleAndReply(MessagingRSocket.java:180)
	|_       Mono.thenMany ⇢ at org.springframework.messaging.rsocket.annotation.support.MessagingRSocket.handleAndReply(MessagingRSocket.java:180)
	|_           Flux.next ⇢ at org.springframework.messaging.rsocket.annotation.support.MessagingRSocket.requestResponse(MessagingRSocket.java:122)
	|_        Mono.flatMap ⇢ at org.springframework.security.rsocket.core.PayloadInterceptorRSocket.requestResponse(PayloadInterceptorRSocket.java:84)

I followed this for jwt with spring boot 2.2.2.RELEASE.

Although, i can see ReactiveSecurityContextHolder getting set with authentication object onAuthenticationSuccess but it's empty when tried getting the same in the controller method.

Thanks