From 9e01d572cf012ddffb1c5e2b504a0db35be98c5e Mon Sep 17 00:00:00 2001
From: JinwooHwang <jinwoo@apache.org>
Date: Mon, 26 Oct 2026 16:47:15 -0400
Subject: [PATCH] GEODE-10684: Make ClientProxyMembershipID read path
 consistent with its write path

---
 .../sanctionedDataSerializables.txt           |  2 +-
 .../tier/sockets/ClientProxyMembershipID.java | 12 +++++++++++-
 .../sockets/ClientProxyMembershipIDTest.java  | 19 +++++++++++++++++++
 3 files changed, 31 insertions(+), 2 deletions(-)

diff --git a/geode-core/src/integrationTest/resources/org/apache/geode/codeAnalysis/sanctionedDataSerializables.txt b/geode-core/src/integrationTest/resources/org/apache/geode/codeAnalysis/sanctionedDataSerializables.txt
index 90c0cd442d30..32aec72df57c 100644
--- a/geode-core/src/integrationTest/resources/org/apache/geode/codeAnalysis/sanctionedDataSerializables.txt
+++ b/geode-core/src/integrationTest/resources/org/apache/geode/codeAnalysis/sanctionedDataSerializables.txt
@@ -1726,7 +1726,7 @@ fromData,1
 toData,1
 
 org/apache/geode/internal/cache/tier/sockets/ClientProxyMembershipID,2
-fromData,19
+fromData,63
 toData,19
 
 org/apache/geode/internal/cache/tier/sockets/ClientReAuthenticateMessage,2
diff --git a/geode-core/src/main/java/org/apache/geode/internal/cache/tier/sockets/ClientProxyMembershipID.java b/geode-core/src/main/java/org/apache/geode/internal/cache/tier/sockets/ClientProxyMembershipID.java
index bae225f78722..1e83fbe7016d 100644
--- a/geode-core/src/main/java/org/apache/geode/internal/cache/tier/sockets/ClientProxyMembershipID.java
+++ b/geode-core/src/main/java/org/apache/geode/internal/cache/tier/sockets/ClientProxyMembershipID.java
@@ -45,6 +45,7 @@
 import org.apache.geode.internal.serialization.DeserializationContext;
 import org.apache.geode.internal.serialization.KnownVersion;
 import org.apache.geode.internal.serialization.SerializationContext;
+import org.apache.geode.internal.serialization.StaticSerialization;
 import org.apache.geode.internal.serialization.Versioning;
 import org.apache.geode.logging.internal.log4j.api.LogService;
 import org.apache.geode.util.internal.GeodeGlossary;
@@ -304,7 +305,16 @@ public void toData(final DataOutput out, final SerializationContext context) thr
   @Override
   public void fromData(final DataInput in, final DeserializationContext context)
       throws IOException, ClassNotFoundException {
-    identity = DataSerializer.readByteArray(in);
+    final int identityLength = StaticSerialization.readArrayLength(in);
+    if (identityLength > Short.MAX_VALUE) {
+      throw new IOException("HandShake identity length is too big");
+    }
+    if (identityLength == -1) {
+      identity = null;
+    } else {
+      identity = new byte[identityLength];
+      in.readFully(identity);
+    }
     uniqueId = in.readInt();
   }
 
diff --git a/geode-core/src/test/java/org/apache/geode/internal/cache/tier/sockets/ClientProxyMembershipIDTest.java b/geode-core/src/test/java/org/apache/geode/internal/cache/tier/sockets/ClientProxyMembershipIDTest.java
index 15662d0c4a03..53652b9f251f 100644
--- a/geode-core/src/test/java/org/apache/geode/internal/cache/tier/sockets/ClientProxyMembershipIDTest.java
+++ b/geode-core/src/test/java/org/apache/geode/internal/cache/tier/sockets/ClientProxyMembershipIDTest.java
@@ -34,6 +34,7 @@
 import org.apache.geode.internal.NullDataOutputStream;
 import org.apache.geode.internal.serialization.ByteArrayDataInput;
 import org.apache.geode.internal.serialization.DSCODE;
+import org.apache.geode.internal.serialization.StaticSerialization;
 
 public class ClientProxyMembershipIDTest {
 
@@ -102,6 +103,24 @@ public void readCanonicalizedReadsFixedIdForm() throws Exception {
     assertThat(ClientProxyMembershipID.readCanonicalized(in)).isNotNull();
   }
 
+  @Test
+  public void fromDataRejectsIdentityLengthThatExceedsMaximum() throws IOException {
+    // A well-formed identity is always small: writeExternal caps it at Short.MAX_VALUE.
+    // fromData applies the same upper bound when reading, so the fixed-id and Externalizable
+    // paths agree on the maximum identity length a client may send.
+    final ByteArrayOutputStream bytes = new ByteArrayOutputStream();
+    final DataOutputStream out = new DataOutputStream(bytes);
+    out.writeByte(StaticSerialization.INT_ARRAY_LEN);
+    out.writeInt(Short.MAX_VALUE + 1);
+    out.close();
+    final ByteArrayDataInput in = new ByteArrayDataInput(bytes.toByteArray());
+    final ClientProxyMembershipID clientProxyMembershipID = new ClientProxyMembershipID();
+
+    assertThatThrownBy(() -> clientProxyMembershipID.fromData(in, null))
+        .isInstanceOf(IOException.class)
+        .hasMessageContaining("identity length is too big");
+  }
+
   public static class ProbeObject implements Serializable {
     static boolean deserialized;