Align Nethermind with the latest taiko-geth changes

src/Nethermind/Nethermind.Taiko/Rpc/TaikoExtendedEthModule.cs

@@ -79,10 +79,9 @@ public class TaikoExtendedEthModule(
     }
 
     /// <summary>
-    /// Traverses the blockchain backwards to find the last Shasta block of the given Shasta batch ID.
+    /// Traverses the blockchain backwards to find the last Shasta block of the given batch ID.
     /// </summary>
-    /// <param name="batchId">The batch ID.</param>
-    /// <returns>The last block ID.</returns>
+    /// <param name="batchId">The Shasta batch identifier for which to find the last corresponding block.</param>
     private UInt256? GetLastBlockByBatchId(UInt256 batchId)
     {
         Block? currentBlock = blockFinder.Head;
@@ -96,8 +95,7 @@ public class TaikoExtendedEthModule(
                 break;
             }
 
-            UInt256? proposalId = ExtractAnchorV4ProposalId(currentBlock.Transactions[0].Data);
-
+            UInt256? proposalId = currentBlock.Header.DecodeShastaProposalID();
             if (proposalId is null)
             {
                 return null;
@@ -118,29 +116,4 @@ private static bool HasAnchorV4Prefix(ReadOnlyMemory<byte> data)
     {
         return data.Length >= 4 && AnchorV4Selector.AsSpan().SequenceEqual(data.Span[..4]);
     }
-
-    private static UInt256? ExtractAnchorV4ProposalId(ReadOnlyMemory<byte> data)
-    {
-        // Calldata layout: 4-byte selector + ABI-encoded arguments.
-        // The first 32 bytes hold the offset (relative to args start) where the proposal id is stored.
-        const int selectorLength = 4;
-        const int dataLength = 32;
-
-        if (data.Length <= selectorLength + dataLength)
-        {
-            return null;
-        }
-
-        ReadOnlySpan<byte> args = data.Span[selectorLength..];
-        var offset = new UInt256(args[..dataLength], true);
-
-        // Check if the offset is invalid
-        if (offset > int.MaxValue || offset + dataLength > args.Length)
-        {
-            return null;
-        }
-
-        ReadOnlySpan<byte> proposalIdBytes = args.Slice((int)offset, dataLength);
-        return new UInt256(proposalIdBytes, true);
-    }
 }

src/Nethermind/Nethermind.Taiko/TaikoBlockValidator.cs

@@ -24,7 +24,7 @@ public class TaikoBlockValidator(
     private static readonly byte[] AnchorSelector = Keccak.Compute("anchor(bytes32,bytes32,uint64,uint32)").Bytes[..4].ToArray();
     private static readonly byte[] AnchorV2Selector = Keccak.Compute("anchorV2(uint64,bytes32,uint32,(uint8,uint8,uint32,uint64,uint32))").Bytes[..4].ToArray();
     private static readonly byte[] AnchorV3Selector = Keccak.Compute("anchorV3(uint64,bytes32,uint32,(uint8,uint8,uint32,uint64,uint32),bytes32[])").Bytes[..4].ToArray();
-    public static readonly byte[] AnchorV4Selector = Keccak.Compute("anchorV4((uint48,address,bytes),(uint48,bytes32,bytes32))").Bytes[..4].ToArray();
+    public static readonly byte[] AnchorV4Selector = Keccak.Compute("anchorV4((uint48,bytes32,bytes32))").Bytes[..4].ToArray();
 
 
     public static readonly Address GoldenTouchAccount = new("0x0000777735367b36bC9B61C50022d9D0700dB4Ec");

src/Nethermind/Nethermind.Taiko/TaikoHeaderHelper.cs

@@ -3,18 +3,44 @@
 
 using System;
 using Nethermind.Core;
+using Nethermind.Int256;
 
 namespace Nethermind.Taiko;
 
+/// <summary>
+/// Helper methods for decoding Taiko block header extraData.
+/// Shasta extraData layout: [basefeeSharingPctg (1 byte)][proposalId (6 bytes)]
+/// </summary>
 internal static class TaikoHeaderHelper
 {
-    public const int ShastaExtraDataMinLen = 2;
+    public const int ShastaExtraDataBasefeeSharingPctgIndex = 0;
+    public const int ShastaExtraDataProposalIDIndex = 1;
+    public const int ShastaExtraDataProposalIDLength = 6;
+    public const int ShastaExtraDataLen = 1 + ShastaExtraDataProposalIDLength;
 
-    public static byte? DecodeOntakeExtraData(this BlockHeader header) => header.ExtraData is { Length: >= 32 } ? Math.Min(header.ExtraData[31], (byte)100) : null;
+    /// <summary>
+    /// Decodes Ontake/Pacaya extraData to get basefeeSharingPctg (last byte, capped at 100).
+    /// </summary>
+    public static byte? DecodeOntakeExtraData(this BlockHeader header) =>
+        header.ExtraData is { Length: >= 32 } ? Math.Min(header.ExtraData[31], (byte)100) : null;
 
-    // Two bytes encoded in the extra data for Shasta
-    // - First byte: basefeeSharingPctg
-    // - Second byte: isLowBondProposal (lowest bit)
-    // Returns only the basefeeSharingPctg
-    public static byte? DecodeShastaExtraData(this BlockHeader header) => header.ExtraData is { Length: < ShastaExtraDataMinLen } ? null : header.ExtraData[0];
+    /// <summary>
+    /// Decodes Shasta extraData to get basefeeSharingPctg (first byte).
+    /// </summary>
+    public static byte? DecodeShastaBasefeeSharingPctg(this BlockHeader header) =>
+        header.ExtraData is { Length: < ShastaExtraDataLen } ? null : header.ExtraData[ShastaExtraDataBasefeeSharingPctgIndex];
+
+    /// <summary>
+    /// Decodes Shasta extraData to get proposalId (bytes 1-6).
+    /// </summary>
+    public static UInt256? DecodeShastaProposalID(this BlockHeader header)
+    {
+        if (header.ExtraData is null || header.ExtraData.Length < ShastaExtraDataLen)
+        {
+            return null;
+        }
+
+        ReadOnlySpan<byte> proposalIdBytes = header.ExtraData.AsSpan(ShastaExtraDataProposalIDIndex, ShastaExtraDataProposalIDLength);
+        return new UInt256(proposalIdBytes, true);
+    }
 }

src/Nethermind/Nethermind.Taiko/TaikoHeaderValidator.cs

@@ -60,9 +60,9 @@ protected override bool ValidateExtraData(BlockHeader header, IReleaseSpec spec,
     {
         var taikoSpec = (ITaikoReleaseSpec)spec;
 
-        if (taikoSpec.IsShastaEnabled && header.ExtraData is { Length: < TaikoHeaderHelper.ShastaExtraDataMinLen })
+        if (taikoSpec.IsShastaEnabled && header.ExtraData is { Length: < TaikoHeaderHelper.ShastaExtraDataLen })
         {
-            error = $"ExtraData must be at least {TaikoHeaderHelper.ShastaExtraDataMinLen} bytes for Shasta, but got {header.ExtraData.Length}";
+            error = $"ExtraData must be at least {TaikoHeaderHelper.ShastaExtraDataLen} bytes for Shasta, but got {header.ExtraData.Length}";
             if (_logger.IsWarn) _logger.Warn($"Invalid block header ({header.Hash}) - {error}");
             return false;
         }
@@ -93,7 +93,7 @@ private bool ValidateEip4396Header(BlockHeader header, BlockHeader parent, IRele
         ulong parentBlockTime = 0;
         if (header.Number > 1)
         {
-            BlockHeader? grandParent = _blockTree?.FindHeader(parent.ParentHash!, BlockTreeLookupOptions.None);
+            BlockHeader? grandParent = _blockTree?.FindHeader(parent.ParentHash!, BlockTreeLookupOptions.None, blockNumber: parent.Number - 1);
             if (grandParent is null)
             {
                 error = $"Ancestor block not found for parent {parent.ParentHash}";

src/Nethermind/Nethermind.Taiko/TaikoTransactionProcessor.cs

@@ -63,7 +63,7 @@ protected override void PayFees(Transaction tx, BlockHeader header, IReleaseSpec
             var taikoSpec = (ITaikoReleaseSpec)spec;
             if (taikoSpec.IsOntakeEnabled || taikoSpec.IsShastaEnabled)
             {
-                byte basefeeSharingPct = (taikoSpec.IsShastaEnabled ? header.DecodeShastaExtraData() : header.DecodeOntakeExtraData()) ?? 0;
+                byte basefeeSharingPct = (taikoSpec.IsShastaEnabled ? header.DecodeShastaBasefeeSharingPctg() : header.DecodeOntakeExtraData()) ?? 0;
 
                 UInt256 feeCoinbase = baseFees * basefeeSharingPct / 100;