Refactor RDP proxy handling and update related tests

agents/rap-node-agent/internal/fabricproto/session_frames.go

@@ -1,6 +1,9 @@
 package fabricproto
 
-import "errors"
+import (
+	"crypto/sha256"
+	"errors"
+)
 
 var (
 	ErrUnsupportedSessionFrame = errors.New("unsupported fabric session frame")
@@ -62,6 +65,7 @@ func (s *Session) HandleFrame(frame Frame) (SessionEvent, []Frame, error) {
 			TrafficClass: frame.TrafficClass,
 			StreamID:     frame.StreamID,
 			Sequence:     frame.Sequence,
+			Payload:      DataAckPayload(frame.Payload),
 		}}, nil
 	case FrameAck:
 		if err := s.Ack(frame.StreamID, frame.Sequence); err != nil {
@@ -103,6 +107,11 @@ func (s *Session) HandleFrame(frame Frame) (SessionEvent, []Frame, error) {
 	}
 }
 
+func DataAckPayload(payload []byte) []byte {
+	sum := sha256.Sum256(payload)
+	return sum[:]
+}
+
 func (s *Session) handleDataFrame(frame Frame) (SessionEvent, error) {
 	s.mu.Lock()
 	defer s.mu.Unlock()

agents/rap-node-agent/internal/fabricproto/session_frames_test.go

@@ -1,6 +1,7 @@
 package fabricproto
 
 import (
+	"bytes"
 	"errors"
 	"testing"
 )
@@ -36,6 +37,9 @@ func TestHandleFrameOpensStreamAndReceivesData(t *testing.T) {
 	if len(responses) != 1 || responses[0].Type != FrameAck || responses[0].StreamID != 7 || responses[0].Sequence != 11 {
 		t.Fatalf("responses = %+v, want ack for stream 7 seq 11", responses)
 	}
+	if !bytes.Equal(responses[0].Payload, DataAckPayload([]byte("rdp-input"))) {
+		t.Fatalf("ack checksum = %x, want sha256 payload checksum", responses[0].Payload)
+	}
 	snapshot := session.Snapshot()
 	if snapshot.FramesReceived != 1 || snapshot.Streams[7].Received != 1 {
 		t.Fatalf("received metrics = %+v stream=%+v", snapshot, snapshot.Streams[7])