From e51312b60d694d86cd9e224488129272ba53af69 Mon Sep 17 00:00:00 2001
From: Jun Luo <4catcode@gmail.com>
Date: Sat, 31 Jan 2026 07:56:49 +0800
Subject: [PATCH] fix: add validation for `ManageDataOperation` value length to
 ensure it does not exceed 64 bytes.

---
 CHANGELOG.md                                  |  1 +
 .../sdk/operations/ManageDataOperation.java   |  3 ++
 .../operations/ManageDataOperationTest.java   | 37 +++++++++++++++++++
 3 files changed, 41 insertions(+)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 21246ff17..28ca6b762 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -6,6 +6,7 @@
 - fix: add stricter validation for Ed25519 Signed Payload.
 - fix: replace assert statements with explicit null checks in `Federation` class to ensure validation is not bypassed when assertions are disabled.
 - fix: add overflow check in `TimeBounds.expiresAfter()` to prevent integer overflow when timeout is too large.
+- fix: add validation for `ManageDataOperation` value length to ensure it does not exceed 64 bytes.
 
 ## 2.2.1
 
diff --git a/src/main/java/org/stellar/sdk/operations/ManageDataOperation.java b/src/main/java/org/stellar/sdk/operations/ManageDataOperation.java
index 882892efa..80a9dbe3b 100644
--- a/src/main/java/org/stellar/sdk/operations/ManageDataOperation.java
+++ b/src/main/java/org/stellar/sdk/operations/ManageDataOperation.java
@@ -73,6 +73,9 @@ public ManageDataOperation build() {
       if (new XdrString(op.name).getBytes().length > 64) {
         throw new IllegalArgumentException("name cannot exceed 64 bytes");
       }
+      if (op.value != null && op.value.length > 64) {
+        throw new IllegalArgumentException("value cannot exceed 64 bytes");
+      }
       return op;
     }
   }
diff --git a/src/test/java/org/stellar/sdk/operations/ManageDataOperationTest.java b/src/test/java/org/stellar/sdk/operations/ManageDataOperationTest.java
index 78f1b02ff..a573ce1da 100644
--- a/src/test/java/org/stellar/sdk/operations/ManageDataOperationTest.java
+++ b/src/test/java/org/stellar/sdk/operations/ManageDataOperationTest.java
@@ -3,6 +3,7 @@
 import static org.junit.Assert.assertArrayEquals;
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertNull;
+import static org.junit.Assert.assertThrows;
 
 import org.junit.Test;
 import org.stellar.sdk.KeyPair;
@@ -57,4 +58,40 @@ public void testManageDataOperationEmptyValue() {
         "AAAAAQAAAAC7JAuE3XvquOnbsgv2SRztjuk4RoBVefQ0rlrFMMQvfAAAAAoAAAAEdGVzdAAAAAA=",
         operation.toXdrBase64());
   }
+
+  @Test
+  public void testManageDataOperationValueExceeds64Bytes() {
+    byte[] value = new byte[65];
+    IllegalArgumentException exception =
+        assertThrows(
+            IllegalArgumentException.class,
+            () -> ManageDataOperation.builder().name("test").value(value).build());
+    assertEquals("value cannot exceed 64 bytes", exception.getMessage());
+  }
+
+  @Test
+  public void testManageDataOperationValueExactly64Bytes() {
+    byte[] value = new byte[64];
+    for (int i = 0; i < 64; i++) {
+      value[i] = (byte) i;
+    }
+    ManageDataOperation operation = ManageDataOperation.builder().name("test").value(value).build();
+    assertArrayEquals(value, operation.getValue());
+  }
+
+  @Test
+  public void testManageDataOperationNameExceeds64Bytes() {
+    String name = "12345678901234567890123456789012345678901234567890123456789012345";
+    IllegalArgumentException exception =
+        assertThrows(
+            IllegalArgumentException.class, () -> ManageDataOperation.builder().name(name).build());
+    assertEquals("name cannot exceed 64 bytes", exception.getMessage());
+  }
+
+  @Test
+  public void testManageDataOperationNameExactly64Bytes() {
+    String name = "1234567890123456789012345678901234567890123456789012345678901234";
+    ManageDataOperation operation = ManageDataOperation.builder().name(name).build();
+    assertEquals(name, operation.getName());
+  }
 }