Fix rlp validate to handle lists ending at the start of another list (h…

…yperledger#8143) * 8053: Add RLPDecodingHelpers.Kind.EM and handle empty lists in AbstractRLPInput Signed-off-by: Matilda Clerke <[email protected]> * Revert previous change, implement new fix Signed-off-by: Matilda Clerke <[email protected]> * Revert previous change, implement new fix Signed-off-by: Matilda Clerke <[email protected]> --------- Signed-off-by: Matilda Clerke <[email protected]>
philosup · Jan 21, 2025 · 5933a2a · 5933a2a
1 parent 702ce74
commit 5933a2a
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Showing 2 changed files with 14 additions and 2 deletions.
diff --git a/ethereum/rlp/src/main/java/org/hyperledger/besu/ethereum/rlp/RLP.java b/ethereum/rlp/src/main/java/org/hyperledger/besu/ethereum/rlp/RLP.java
@@ -187,10 +187,11 @@ public static Bytes decodeOne(final Bytes encodedValue) {
   public static void validate(final Bytes encodedValue) {
     final RLPInput in = input(encodedValue);
     while (!in.isDone()) {
+      while (in.isEndOfCurrentList()) {
+        in.leaveList();
+      }
       if (in.nextIsList()) {
         in.enterList();
-      } else if (in.isEndOfCurrentList()) {
-        in.leaveList();
       } else {
         // Skip does as much validation as can be done in general, without allocating anything.
         in.skipNext();

diff --git a/ethereum/rlp/src/test/java/org/hyperledger/besu/ethereum/rlp/RLPTest.java b/ethereum/rlp/src/test/java/org/hyperledger/besu/ethereum/rlp/RLPTest.java
@@ -168,6 +168,17 @@ public void calculateSize_overflowMaxRLPStringLength() {
         .hasMessageContaining("RLP item exceeds max supported size of 2147483647: 2147483648");
   }
 
+  @Test
+  public void testValidateWithListEndingAtStartOfList() {
+    // The structue of the RLP is as shown below
+    // [
+    //  ["0x01"],
+    //  ["0x02"]
+    // ]
+    Bytes validRlp = Bytes.fromHexString("c4c101c102");
+    RLP.validate(validRlp);
+  }
+
   private static Bytes h(final String hex) {
     return Bytes.fromHexString(hex);
   }