core/types: support yParity field in JSON transactions (#27744)

This adds support for the "yParity" field in transaction objects returned by RPC
APIs. We somehow forgot to add this field even though it has been in the spec for
a long time.

core/types/transaction_marshalling.go

@@ -45,11 +45,32 @@ type txJSON struct {
 	V                    *hexutil.Big    `json:"v"`
 	R                    *hexutil.Big    `json:"r"`
 	S                    *hexutil.Big    `json:"s"`
+	YParity              *hexutil.Uint64 `json:"yParity,omitempty"`
 
 	// Only used for encoding:
 	Hash common.Hash `json:"hash"`
 }
 
+// yParityValue returns the YParity value from JSON. For backwards-compatibility reasons,
+// this can be given in the 'v' field or the 'yParity' field. If both exist, they must match.
+func (tx *txJSON) yParityValue() (*big.Int, error) {
+	if tx.YParity != nil {
+		val := uint64(*tx.YParity)
+		if val != 0 && val != 1 {
+			return nil, errors.New("'yParity' field must be 0 or 1")
+		}
+		bigval := new(big.Int).SetUint64(val)
+		if tx.V != nil && tx.V.ToInt().Cmp(bigval) != 0 {
+			return nil, errors.New("'v' and 'yParity' fields do not match")
+		}
+		return bigval, nil
+	}
+	if tx.V != nil {
+		return tx.V.ToInt(), nil
+	}
+	return nil, errors.New("missing 'yParity' or 'v' field in transaction")
+}
+
 // MarshalJSON marshals as JSON with a hash.
 func (tx *Transaction) MarshalJSON() ([]byte, error) {
 	var enc txJSON
@@ -85,6 +106,8 @@ func (tx *Transaction) MarshalJSON() ([]byte, error) {
 		enc.V = (*hexutil.Big)(itx.V)
 		enc.R = (*hexutil.Big)(itx.R)
 		enc.S = (*hexutil.Big)(itx.S)
+		yparity := itx.V.Uint64()
+		enc.YParity = (*hexutil.Uint64)(&yparity)
 
 	case *DynamicFeeTx:
 		enc.ChainID = (*hexutil.Big)(itx.ChainID)
@@ -99,6 +122,8 @@ func (tx *Transaction) MarshalJSON() ([]byte, error) {
 		enc.V = (*hexutil.Big)(itx.V)
 		enc.R = (*hexutil.Big)(itx.R)
 		enc.S = (*hexutil.Big)(itx.S)
+		yparity := itx.V.Uint64()
+		enc.YParity = (*hexutil.Uint64)(&yparity)
 
 	case *BlobTx:
 		enc.ChainID = (*hexutil.Big)(itx.ChainID.ToBig())
@@ -115,6 +140,8 @@ func (tx *Transaction) MarshalJSON() ([]byte, error) {
 		enc.V = (*hexutil.Big)(itx.V.ToBig())
 		enc.R = (*hexutil.Big)(itx.R.ToBig())
 		enc.S = (*hexutil.Big)(itx.S.ToBig())
+		yparity := itx.V.Uint64()
+		enc.YParity = (*hexutil.Uint64)(&yparity)
 	}
 	return json.Marshal(&enc)
 }
@@ -122,7 +149,8 @@ func (tx *Transaction) MarshalJSON() ([]byte, error) {
 // UnmarshalJSON unmarshals from JSON.
 func (tx *Transaction) UnmarshalJSON(input []byte) error {
 	var dec txJSON
-	if err := json.Unmarshal(input, &dec); err != nil {
+	err := json.Unmarshal(input, &dec)
+	if err != nil {
 		return err
 	}
 
@@ -155,20 +183,23 @@ func (tx *Transaction) UnmarshalJSON(input []byte) error {
 			return errors.New("missing required field 'input' in transaction")
 		}
 		itx.Data = *dec.Input
-		if dec.V == nil {
+
-			return errors.New("missing required field 'v' in transaction")
+		// signature R
-		}
-		itx.V = (*big.Int)(dec.V)
 		if dec.R == nil {
 			return errors.New("missing required field 'r' in transaction")
 		}
 		itx.R = (*big.Int)(dec.R)
+		// signature S
 		if dec.S == nil {
 			return errors.New("missing required field 's' in transaction")
 		}
 		itx.S = (*big.Int)(dec.S)
-		withSignature := itx.V.Sign() != 0 || itx.R.Sign() != 0 || itx.S.Sign() != 0
+		// signature V
-		if withSignature {
+		if dec.V == nil {
+			return errors.New("missing required field 'v' in transaction")
+		}
+		itx.V = (*big.Int)(dec.V)
+		if itx.V.Sign() != 0 || itx.R.Sign() != 0 || itx.S.Sign() != 0 {
 			if err := sanityCheckSignature(itx.V, itx.R, itx.S, true); err != nil {
 				return err
 			}
@@ -204,23 +235,26 @@ func (tx *Transaction) UnmarshalJSON(input []byte) error {
 			return errors.New("missing required field 'input' in transaction")
 		}
 		itx.Data = *dec.Input
-		if dec.V == nil {
-			return errors.New("missing required field 'v' in transaction")
-		}
 		if dec.AccessList != nil {
 			itx.AccessList = *dec.AccessList
 		}
-		itx.V = (*big.Int)(dec.V)
+
+		// signature R
 		if dec.R == nil {
 			return errors.New("missing required field 'r' in transaction")
 		}
 		itx.R = (*big.Int)(dec.R)
+		// signature S
 		if dec.S == nil {
 			return errors.New("missing required field 's' in transaction")
 		}
 		itx.S = (*big.Int)(dec.S)
-		withSignature := itx.V.Sign() != 0 || itx.R.Sign() != 0 || itx.S.Sign() != 0
+		// signature V
-		if withSignature {
+		itx.V, err = dec.yParityValue()
+		if err != nil {
+			return err
+		}
+		if itx.V.Sign() != 0 || itx.R.Sign() != 0 || itx.S.Sign() != 0 {
 			if err := sanityCheckSignature(itx.V, itx.R, itx.S, false); err != nil {
 				return err
 			}
@@ -266,17 +300,23 @@ func (tx *Transaction) UnmarshalJSON(input []byte) error {
 		if dec.AccessList != nil {
 			itx.AccessList = *dec.AccessList
 		}
-		itx.V = (*big.Int)(dec.V)
+
+		// signature R
 		if dec.R == nil {
 			return errors.New("missing required field 'r' in transaction")
 		}
 		itx.R = (*big.Int)(dec.R)
+		// signature S
 		if dec.S == nil {
 			return errors.New("missing required field 's' in transaction")
 		}
 		itx.S = (*big.Int)(dec.S)
-		withSignature := itx.V.Sign() != 0 || itx.R.Sign() != 0 || itx.S.Sign() != 0
+		// signature V
-		if withSignature {
+		itx.V, err = dec.yParityValue()
+		if err != nil {
+			return err
+		}
+		if itx.V.Sign() != 0 || itx.R.Sign() != 0 || itx.S.Sign() != 0 {
 			if err := sanityCheckSignature(itx.V, itx.R, itx.S, false); err != nil {
 				return err
 			}
@@ -331,18 +371,35 @@ func (tx *Transaction) UnmarshalJSON(input []byte) error {
 			return errors.New("missing required field 'blobVersionedHashes' in transaction")
 		}
 		itx.BlobHashes = dec.BlobVersionedHashes
-		itx.V = uint256.MustFromBig((*big.Int)(dec.V))
+
+		// signature R
+		var ok bool
 		if dec.R == nil {
 			return errors.New("missing required field 'r' in transaction")
 		}
-		itx.R = uint256.MustFromBig((*big.Int)(dec.R))
+		itx.R, ok = uint256.FromBig((*big.Int)(dec.R))
+		if !ok {
+			return errors.New("'r' value overflows uint256")
+		}
+		// signature S
 		if dec.S == nil {
 			return errors.New("missing required field 's' in transaction")
 		}
-		itx.S = uint256.MustFromBig((*big.Int)(dec.S))
+		itx.S, ok = uint256.FromBig((*big.Int)(dec.S))
-		withSignature := itx.V.Sign() != 0 || itx.R.Sign() != 0 || itx.S.Sign() != 0
+		if !ok {
-		if withSignature {
+			return errors.New("'s' value overflows uint256")
-			if err := sanityCheckSignature(itx.V.ToBig(), itx.R.ToBig(), itx.S.ToBig(), false); err != nil {
+		}
+		// signature V
+		vbig, err := dec.yParityValue()
+		if err != nil {
+			return err
+		}
+		itx.V, ok = uint256.FromBig(vbig)
+		if !ok {
+			return errors.New("'v' value overflows uint256")
+		}
+		if itx.V.Sign() != 0 || itx.R.Sign() != 0 || itx.S.Sign() != 0 {
+			if err := sanityCheckSignature(vbig, itx.R.ToBig(), itx.S.ToBig(), false); err != nil {
 				return err
 			}
 		}

internal/ethapi/api.go

@@ -1375,6 +1375,7 @@ type RPCTransaction struct {
 	V                *hexutil.Big      `json:"v"`
 	R                *hexutil.Big      `json:"r"`
 	S                *hexutil.Big      `json:"s"`
+	YParity          *hexutil.Uint64   `json:"yParity,omitempty"`
 }
 
 // newRPCTransaction returns a transaction that will serialize to the RPC
@@ -1402,20 +1403,27 @@ func newRPCTransaction(tx *types.Transaction, blockHash common.Hash, blockNumber
 		result.BlockNumber = (*hexutil.Big)(new(big.Int).SetUint64(blockNumber))
 		result.TransactionIndex = (*hexutil.Uint64)(&index)
 	}
+
 	switch tx.Type() {
 	case types.LegacyTxType:
 		// if a legacy transaction has an EIP-155 chain id, include it explicitly
 		if id := tx.ChainId(); id.Sign() != 0 {
 			result.ChainID = (*hexutil.Big)(id)
 		}
+
 	case types.AccessListTxType:
 		al := tx.AccessList()
+		yparity := hexutil.Uint64(v.Sign())
 		result.Accesses = &al
 		result.ChainID = (*hexutil.Big)(tx.ChainId())
+		result.YParity = &yparity
+
 	case types.DynamicFeeTxType:
 		al := tx.AccessList()
+		yparity := hexutil.Uint64(v.Sign())
 		result.Accesses = &al
 		result.ChainID = (*hexutil.Big)(tx.ChainId())
+		result.YParity = &yparity
 		result.GasFeeCap = (*hexutil.Big)(tx.GasFeeCap())
 		result.GasTipCap = (*hexutil.Big)(tx.GasTipCap())
 		// if the transaction has been mined, compute the effective gas price