Merge pull request #73 from emeraldpay/feature/eip4844-transaction

solution: RLP encoding for EIP-4844 transactions
emeraldpay · Mar 15, 2024 · 0b06f99 · 0b06f99
2 parents 2e6ae0d + bd4bb3f
commit 0b06f99
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Showing 9 changed files with 266 additions and 28 deletions.
diff --git a/etherjar-tx/src/main/java/io/emeraldpay/etherjar/tx/Transaction.java b/etherjar-tx/src/main/java/io/emeraldpay/etherjar/tx/Transaction.java
@@ -152,7 +152,7 @@ public byte[] hash() {
     }
 
     public byte[] hash(Integer chainId) {
-        byte[] rlp = TransactionEncoder.DEFAULT.encode(this, false, chainId);
+        byte[] rlp = TransactionEncoder.DEFAULT.encodeStandard(this, false, chainId);
 
         Keccak.Digest256 keccak = new Keccak.Digest256();
         keccak.update(rlp);

diff --git a/etherjar-tx/src/main/java/io/emeraldpay/etherjar/tx/TransactionDecoder.java b/etherjar-tx/src/main/java/io/emeraldpay/etherjar/tx/TransactionDecoder.java
@@ -41,6 +41,9 @@ public Transaction decode(byte[] raw) {
         if (type == TransactionType.GAS_PRIORITY) {
             return decodeGasPriority(raw);
         }
+        if (type == TransactionType.BLOB) {
+            return decodeBlob(raw);
+        }
         if (type == TransactionType.STANDARD) {
             return decodeStandard(raw);
         }
@@ -130,6 +133,24 @@ public TransactionWithGasPriority decodeGasPriority(byte[] raw) {
         return tx;
     }
 
+    public TransactionWithBlob decodeBlob(byte[] raw) {
+        // rlp([chain_id, nonce, max_priority_fee_per_gas, max_fee_per_gas, gas_limit, to, value, data, access_list, max_fee_per_blob_gas, blob_versioned_hashes, y_parity, r, s])
+        RlpReader rdr = startReader(raw, 1);
+        TransactionWithBlob tx = new TransactionWithBlob();
+        readChainId(rdr, tx);
+        readNonce(rdr, tx);
+        readPriorityGasPrice(rdr, tx);
+        readMaxGasPrice(rdr, tx);
+        readGasLimit(rdr, tx);
+        readBodyPart(rdr, tx);
+
+        readAccessList(rdr, tx);
+        readBlob(rdr, tx);
+        tryReadSignature(rdr, tx);
+        ensureFullyRead(rdr);
+        return tx;
+    }
+
     private RlpReader startReader(byte[] raw, int position) {
         RlpReader toprdr = new RlpReader(raw, position, raw.length - position);
         if (toprdr.getType() != RlpType.LIST) {
@@ -210,6 +231,26 @@ private void readAccessList(RlpReader rdr, TransactionWithAccess tx) {
         }
     }
 
+    protected void readBlob(RlpReader rdr, TransactionWithBlob tx) {
+        // The field max_fee_per_blob_gas is a uint256
+        if (rdr.hasNext() && rdr.getType() == RlpType.BYTES) {
+            tx.setMaxFeePerBlobGas(new Wei(rdr.nextBigInt()));
+        } else {
+            throw new IllegalArgumentException("Transaction has invalid RLP encoding. Cannot extract: Max Fee Per Blob Gas");
+        }
+        // the field blob_versioned_hashes represents a list of hash outputs from kzg_to_versioned_hash.
+        if (rdr.hasNext() && rdr.getType() == RlpType.LIST) {
+            RlpReader blobVersionedHashesRdr = rdr.nextList();
+            List<Hex32> blobVersionedHashes = new ArrayList<>();
+            while (blobVersionedHashesRdr.hasNext()) {
+                blobVersionedHashes.add(Hex32.from(blobVersionedHashesRdr.next()));
+            }
+            tx.setBlobVersionedHashes(blobVersionedHashes);
+        } else {
+            throw new IllegalArgumentException("Transaction has invalid RLP encoding. Not a list: Blob Versioned Hashes");
+        }
+    }
+
     protected void readDefinitionsPart(RlpReader rdr, Transaction tx) {
         readNonce(rdr, tx);
         readGasPrice(rdr, tx);

diff --git a/etherjar-tx/src/main/java/io/emeraldpay/etherjar/tx/TransactionEncoder.java b/etherjar-tx/src/main/java/io/emeraldpay/etherjar/tx/TransactionEncoder.java
@@ -29,17 +29,20 @@ public byte[] encode(Transaction tx, boolean includeSignature) {
         if (tx.getType() == TransactionType.GAS_PRIORITY) {
             return encode((TransactionWithGasPriority) tx, includeSignature);
         }
+        if (tx.getType() == TransactionType.BLOB) {
+            return encode((TransactionWithBlob) tx, includeSignature);
+        }
         if (tx.getType() == TransactionType.ACCESS_LIST) {
             return encode((TransactionWithAccess) tx, includeSignature);
         }
         if (tx.getType() == TransactionType.STANDARD) {
             if (includeSignature) {
-                return encode(tx, true, null);
+                return encodeStandard(tx, true, null);
             } else {
                 Signature signature = tx.getSignature();
                 if (signature.getType() == SignatureType.EIP155) {
                     int chainId = ((SignatureEIP155)signature).getChainId();
-                    return encode(tx, false, chainId);
+                    return encodeStandard(tx, false, chainId);
                 } else {
                     throw new IllegalStateException("Neither signature nor chainId specified");
                 }
@@ -48,7 +51,7 @@ public byte[] encode(Transaction tx, boolean includeSignature) {
         throw new IllegalStateException("Unsupported transaction type: " + tx.getType());
     }
 
-    public byte[] encode(Transaction tx, boolean includeSignature, Integer chainId) {
+    protected byte[] encodeStandard(Transaction tx, boolean includeSignature, Integer chainId) {
         RlpWriter wrt = new RlpWriter();
         wrt.startList()
             .write(tx.getNonce())
@@ -90,7 +93,7 @@ public byte[] encode(Transaction tx, boolean includeSignature, Integer chainId)
         return wrt.toByteArray();
     }
 
-    protected void writeBody(RlpWriter wrt, TransactionWithAccess tx, boolean includeSignature) {
+    protected void writeBody(RlpWriter wrt, Transaction tx) {
         if (tx.getTo() != null) {
             wrt.write(tx.getTo().getBytes());
         } else {
@@ -108,7 +111,9 @@ protected void writeBody(RlpWriter wrt, TransactionWithAccess tx, boolean includ
         } else {
             wrt.write(new byte[0]);
         }
+    }
 
+    private static void writeAccessList(RlpWriter wrt, TransactionWithAccess tx) {
         wrt.startList();
         for (TransactionWithAccess.Access access: tx.getAccessList()) {
             wrt.startList();
@@ -121,27 +126,35 @@ protected void writeBody(RlpWriter wrt, TransactionWithAccess tx, boolean includ
             wrt.closeList();
         }
         wrt.closeList();
+    }
 
-        if (includeSignature) {
-            Signature signature = tx.getSignature();
-            if (signature == null) {
-                // just empty signature
-                wrt.write(0)
-                    .write(0)
-                    .write(0);
-            } else {
-                if (signature.getType() == SignatureType.EIP2930) {
-                    int yParity = ((SignatureEIP2930)signature).getYParity();
-                    if (yParity == 0) {
-                        wrt.write(0);
-                    } else {
-                        wrt.write(Integer.valueOf(yParity).byteValue());
-                    }
-                    wrt.write(signature.getR());
-                    wrt.write(signature.getS());
+    private static void writeBlob(RlpWriter wrt, TransactionWithBlob tx) {
+        wrt.write(tx.getMaxFeePerBlobGas().getAmount());
+        wrt.startList();
+        for (Hex32 hash: tx.getBlobVersionedHashes()) {
+            wrt.write(hash.getBytes());
+        }
+        wrt.closeList();
+    }
+
+    private static void writeSignature(RlpWriter wrt, Signature signature) {
+        if (signature == null) {
+            // just empty signature
+            wrt.write(0)
+                .write(0)
+                .write(0);
+        } else {
+            if (signature.getType() == SignatureType.EIP2930) {
+                int yParity = ((SignatureEIP2930)signature).getYParity();
+                if (yParity == 0) {
+                    wrt.write(0);
                 } else {
-                    throw new ClassCastException("Required signature " + SignatureEIP2930.class.getName() + " but have " + signature.getClass().getName());
+                    wrt.write(Integer.valueOf(yParity).byteValue());
                 }
+                wrt.write(signature.getR());
+                wrt.write(signature.getS());
+            } else {
+                throw new ClassCastException("Required signature " + SignatureEIP2930.class.getName() + " but have " + signature.getClass().getName());
             }
         }
     }
@@ -155,7 +168,11 @@ public byte[] encode(TransactionWithAccess tx, boolean includeSignature) {
             .write(tx.getNonce())
             .write(tx.getGasPrice().getAmount())
             .write(tx.getGas());
-        writeBody(wrt, tx, includeSignature);
+        writeBody(wrt, tx);
+        writeAccessList(wrt, tx);
+        if (includeSignature) {
+            writeSignature(wrt, tx.getSignature());
+        }
         wrt.closeList();
         return buffer.toByteArray();
     }
@@ -170,7 +187,31 @@ public byte[] encode(TransactionWithGasPriority tx, boolean includeSignature) {
             .write(tx.getPriorityGasPrice().getAmount())
             .write(tx.getMaxGasPrice().getAmount())
             .write(tx.getGas());
-        writeBody(wrt, tx, includeSignature);
+        writeBody(wrt, tx);
+        writeAccessList(wrt, tx);
+        if (includeSignature) {
+            writeSignature(wrt, tx.getSignature());
+        }
+        wrt.closeList();
+        return buffer.toByteArray();
+    }
+
+    public byte[] encode(TransactionWithBlob tx, boolean includeSignature) {
+        ByteArrayOutputStream buffer = new ByteArrayOutputStream();
+        buffer.write(TransactionType.BLOB.getFlag());
+        RlpWriter wrt = new RlpWriter(buffer);
+        wrt.startList()
+            .write(tx.getChainId())
+            .write(tx.getNonce())
+            .write(tx.getPriorityGasPrice().getAmount())
+            .write(tx.getMaxGasPrice().getAmount())
+            .write(tx.getGas());
+        writeBody(wrt, tx);
+        writeAccessList(wrt, tx);
+        writeBlob(wrt, tx);
+        if (includeSignature) {
+            writeSignature(wrt, tx.getSignature());
+        }
         wrt.closeList();
         return buffer.toByteArray();
     }

diff --git a/etherjar-tx/src/main/java/io/emeraldpay/etherjar/tx/TransactionType.java b/etherjar-tx/src/main/java/io/emeraldpay/etherjar/tx/TransactionType.java
@@ -34,7 +34,13 @@ public enum TransactionType {
      * Transaction with Gas Max and Priority prices.
      * @see <a href="https://eips.ethereum.org/EIPS/eip-1559">EIP-1559</a>
      */
-    GAS_PRIORITY((byte)2);
+    GAS_PRIORITY((byte)2),
+
+    /**
+     * Blob transaction
+     * @see <a href="https://eips.ethereum.org/EIPS/eip-4844">EIP-4844</a>
+     */
+    BLOB((byte)3);
 
     private final byte flag;
 
@@ -63,6 +69,9 @@ public static TransactionType fromPrefix(byte prefix) {
             if (u == 2) {
                 return TransactionType.GAS_PRIORITY;
             }
+            if (u == 3) {
+                return TransactionType.BLOB;
+            }
             if (u == 1) {
                 return TransactionType.ACCESS_LIST;
             }

diff --git a/etherjar-tx/src/main/java/io/emeraldpay/etherjar/tx/TransactionWithBlob.java b/etherjar-tx/src/main/java/io/emeraldpay/etherjar/tx/TransactionWithBlob.java
@@ -0,0 +1,51 @@
+package io.emeraldpay.etherjar.tx;
+
+import io.emeraldpay.etherjar.domain.Wei;
+import io.emeraldpay.etherjar.hex.Hex32;
+import org.bouncycastle.jcajce.provider.digest.Keccak;
+
+import java.util.List;
+
+/**
+ * Transaction with Blobs (EIP-2718)
+ *
+ * @see <a href="https://eips.ethereum.org/EIPS/eip-2718">EIP-2718</a>
+ */
+public class TransactionWithBlob extends TransactionWithGasPriority {
+
+    private Wei maxFeePerBlobGas;
+
+    /**
+     * Represents a list of hash outputs from kzg_to_versioned_hash
+     */
+    private List<Hex32> blobVersionedHashes;
+
+    public Wei getMaxFeePerBlobGas() {
+        return maxFeePerBlobGas;
+    }
+
+    public void setMaxFeePerBlobGas(Wei maxFeePerBlobGas) {
+        this.maxFeePerBlobGas = maxFeePerBlobGas;
+    }
+
+    public List<Hex32> getBlobVersionedHashes() {
+        return blobVersionedHashes;
+    }
+
+    public void setBlobVersionedHashes(List<Hex32> blobVersionedHashes) {
+        this.blobVersionedHashes = blobVersionedHashes;
+    }
+
+    @Override
+    public TransactionType getType() {
+        return TransactionType.BLOB;
+    }
+
+    @Override
+    public byte[] hash() {
+        byte[] rlp = TransactionEncoder.DEFAULT.encode(this, false);
+        Keccak.Digest256 keccak = new Keccak.Digest256();
+        keccak.update(rlp);
+        return keccak.digest();
+    }
+}