Support public key recovery for EIP-155 transactions

crypto/src/main/java/org/web3j/crypto/Sign.java

@@ -27,6 +27,7 @@
 import org.bouncycastle.math.ec.FixedPointCombMultiplier;
 import org.bouncycastle.math.ec.custom.sec.SecP256K1Curve;
 
+import org.web3j.commons.ChainId;
 import org.web3j.utils.Numeric;
 
 import static org.bouncycastle.util.BigIntegers.TWO;
@@ -272,7 +273,7 @@
      */
     public static BigInteger signedMessageToKey(byte[] message, SignatureData signatureData)
             throws SignatureException {
-        return signedMessageHashToKey(Hash.sha3(message), signatureData);
+        return signedMessageHashToKey(Hash.sha3(message), signatureData, ChainId.MAIN_NET);
     }
 
     /**
@@ -288,9 +289,12 @@
      */
     public static BigInteger signedPrefixedMessageToKey(byte[] message, SignatureData signatureData)
             throws SignatureException {
-        return signedMessageHashToKey(getEthereumMessageHash(message), signatureData);
+        return signedPrefixedMessageToKey(message, signatureData, ChainId.MAIN_NET);
+    }
+    public static BigInteger signedPrefixedMessageToKey(byte[] message, SignatureData signatureData, ChainId chainId)
+            throws SignatureException {
+        return signedMessageHashToKey(getEthereumMessageHash(message), signatureData, chainId);
     }
-
     /**
      * Given an arbitrary message hash and an Ethereum message signature encoded in bytes, returns
      * the public key that was used to sign it. This can then be compared to the expected public key
@@ -302,27 +306,38 @@
      * @throws SignatureException If the public key could not be recovered or if there was a
      *     signature format error.
      */
+    @Deprecated
     public static BigInteger signedMessageHashToKey(byte[] messageHash, SignatureData signatureData)
             throws SignatureException {
+        return signedPrefixedMessageToKey(messageHash, signatureData, ChainId.MAIN_NET);
+    }
+
+    /**
+     * Given an arbitrary message hash and an Ethereum message signature encoded in bytes, returns
+     * the public key that was used to sign it. This can then be compared to the expected public key
+     * to determine if the signature was correct.
+     *
+     * @param messageHash The message hash.
+     * @param signatureData The message signature components
+     * @param chainId of the network
+     * @return the public key used to sign the message
+     * @throws SignatureException If the public key could not be recovered or if there was a
+     *     signature format error.
+     */
+    public static BigInteger signedMessageHashToKey(byte[] messageHash, SignatureData signatureData, ChainId chainId)
+            throws SignatureException {
 
         byte[] r = signatureData.getR();
         byte[] s = signatureData.getS();
         verifyPrecondition(r != null && r.length == 32, "r must be 32 bytes");
         verifyPrecondition(s != null && s.length == 32, "s must be 32 bytes");
 
-        int header = signatureData.getV()[0] & 0xFF;
-        // The header byte: 0x1B = first key with even y, 0x1C = first key with odd y,
-        //                  0x1D = second key with even y, 0x1E = second key with odd y
-        if (header < 27 || header > 34) {
-            throw new SignatureException("Header byte out of range: " + header);
-        }
-
         ECDSASignature sig =
                 new ECDSASignature(
                         new BigInteger(1, signatureData.getR()),
                         new BigInteger(1, signatureData.getS()));
 
-        int recId = header - 27;
+        int recId = Sign.getRecId(signatureData, chainId.getId());
         BigInteger key = recoverFromSignature(recId, sig, messageHash);
         if (key == null) {
             throw new SignatureException("Could not recover public key from signature");

crypto/src/test/java/org/web3j/crypto/SignTest.java

@@ -25,6 +25,7 @@
 import org.junit.jupiter.params.provider.Arguments;
 import org.junit.jupiter.params.provider.MethodSource;
 
+import org.web3j.commons.ChainId;
 import org.web3j.utils.Numeric;
 
 import static org.junit.jupiter.api.Assertions.assertEquals;
@@ -116,6 +117,15 @@ public void testFromHex() throws SignatureException {
         assertEquals(signatureData, (expected));
     }
 
+    @Test
+    public void testSignedPrefixedMessageToKeyWithEip155() throws SignatureException {
+        Sign.SignatureData signatureData = Sign.signPrefixedMessage(TEST_MESSAGE, SampleKeys.KEY_PAIR);
+        assert(signatureData.getV()[0] == 28);
+        signatureData.getV()[0] = (byte)(ChainId.GOERLI.getId() * 2 + 36);
+        BigInteger key = Sign.signedPrefixedMessageToKey(TEST_MESSAGE, signatureData, ChainId.GOERLI);
+        assertEquals(key, (SampleKeys.  PUBLIC_KEY));
+    }
+
     @ParameterizedTest(name = "testGetRecId(chainId={0}, recId={1}, isEip155={2})")
     @MethodSource("recIdArguments")
     public void testGetRecId(final long chainId, final long recId, final boolean isEip155) {

utils/src/main/java/org/web3j/commons/ChainId.java

@@ -13,7 +13,9 @@
 package org.web3j.commons;
 
 public enum ChainId {
-    MAIN_NET(1);
+    MAIN_NET(1),
+    GOERLI(5),
+    SEPOLIA(58008);
 
     private int id;