From c79d802450a63a9f1f757b3872cd2ce7680eecb5 Mon Sep 17 00:00:00 2001
From: Neil Twigg <neil@nats.io>
Date: Mon, 6 Jan 2025 12:17:37 +0000
Subject: [PATCH] Strip unnecessary `ClientInfo` fields from stream & consumer
 assignment proposals

Signed-off-by: Neil Twigg <neil@nats.io>
---
 server/events.go            | 11 ++++++++++
 server/jetstream_cluster.go | 40 +++++++++++++++++++++----------------
 2 files changed, 34 insertions(+), 17 deletions(-)

diff --git a/server/events.go b/server/events.go
index a91eaec92c..eeff78c18e 100644
--- a/server/events.go
+++ b/server/events.go
@@ -336,6 +336,17 @@ func (ci *ClientInfo) forAssignmentSnap() *ClientInfo {
 	}
 }
 
+// forProposal returns the minimum amount of ClientInfo we need for assignment proposals.
+func (ci *ClientInfo) forProposal() *ClientInfo {
+	if ci == nil {
+		return nil
+	}
+	cci := *ci
+	cci.Jwt = _EMPTY_
+	cci.IssuerKey = _EMPTY_
+	return &cci
+}
+
 // ServerStats hold various statistics that we will periodically send out.
 type ServerStats struct {
 	Start              time.Time           `json:"start"`
diff --git a/server/jetstream_cluster.go b/server/jetstream_cluster.go
index 8e250fbff7..59f1d9f9e4 100644
--- a/server/jetstream_cluster.go
+++ b/server/jetstream_cluster.go
@@ -7297,23 +7297,29 @@ func (s *Server) jsClusteredMsgDeleteRequest(ci *ClientInfo, acc *Account, mset
 }
 
 func encodeAddStreamAssignment(sa *streamAssignment) []byte {
+	csa := *sa
+	csa.Client = csa.Client.forProposal()
 	var bb bytes.Buffer
 	bb.WriteByte(byte(assignStreamOp))
-	json.NewEncoder(&bb).Encode(sa)
+	json.NewEncoder(&bb).Encode(csa)
 	return bb.Bytes()
 }
 
 func encodeUpdateStreamAssignment(sa *streamAssignment) []byte {
+	csa := *sa
+	csa.Client = csa.Client.forProposal()
 	var bb bytes.Buffer
 	bb.WriteByte(byte(updateStreamOp))
-	json.NewEncoder(&bb).Encode(sa)
+	json.NewEncoder(&bb).Encode(csa)
 	return bb.Bytes()
 }
 
 func encodeDeleteStreamAssignment(sa *streamAssignment) []byte {
+	csa := *sa
+	csa.Client = csa.Client.forProposal()
 	var bb bytes.Buffer
 	bb.WriteByte(byte(removeStreamOp))
-	json.NewEncoder(&bb).Encode(sa)
+	json.NewEncoder(&bb).Encode(csa)
 	return bb.Bytes()
 }
 
@@ -7723,16 +7729,20 @@ func (s *Server) jsClusteredConsumerRequest(ci *ClientInfo, acc *Account, subjec
 }
 
 func encodeAddConsumerAssignment(ca *consumerAssignment) []byte {
+	cca := *ca
+	cca.Client = cca.Client.forProposal()
 	var bb bytes.Buffer
 	bb.WriteByte(byte(assignConsumerOp))
-	json.NewEncoder(&bb).Encode(ca)
+	json.NewEncoder(&bb).Encode(cca)
 	return bb.Bytes()
 }
 
 func encodeDeleteConsumerAssignment(ca *consumerAssignment) []byte {
+	cca := *ca
+	cca.Client = cca.Client.forProposal()
 	var bb bytes.Buffer
 	bb.WriteByte(byte(removeConsumerOp))
-	json.NewEncoder(&bb).Encode(ca)
+	json.NewEncoder(&bb).Encode(cca)
 	return bb.Bytes()
 }
 
@@ -7743,25 +7753,21 @@ func decodeConsumerAssignment(buf []byte) (*consumerAssignment, error) {
 }
 
 func encodeAddConsumerAssignmentCompressed(ca *consumerAssignment) []byte {
-	b, err := json.Marshal(ca)
-	if err != nil {
-		return nil
-	}
-	// TODO(dlc) - Streaming better approach here probably.
+	cca := *ca
+	cca.Client = cca.Client.forProposal()
 	var bb bytes.Buffer
 	bb.WriteByte(byte(assignCompressedConsumerOp))
-	bb.Write(s2.Encode(nil, b))
+	s2e := s2.NewWriter(&bb)
+	json.NewEncoder(s2e).Encode(cca)
+	s2e.Close()
 	return bb.Bytes()
 }
 
 func decodeConsumerAssignmentCompressed(buf []byte) (*consumerAssignment, error) {
 	var ca consumerAssignment
-	js, err := s2.Decode(nil, buf)
-	if err != nil {
-		return nil, err
-	}
-	err = json.Unmarshal(js, &ca)
-	return &ca, err
+	bb := bytes.NewBuffer(buf)
+	s2d := s2.NewReader(bb)
+	return &ca, json.NewDecoder(s2d).Decode(&ca)
 }
 
 var errBadStreamMsg = errors.New("jetstream cluster bad replicated stream msg")