core, core/types: implement unchained flag in SetCodeAuthorization

core/blockchain_test.go

@@ -4273,13 +4273,12 @@ func TestEIP7702(t *testing.T) {
 	// 1. tx -> addr1 which is delegated to 0xaaaa
 	// 2. addr1:0xaaaa calls into addr2:0xbbbb
 	// 3. addr2:0xbbbb  writes to storage
-	auth1, _ := types.SignSetCode(key1, types.SetCodeAuthorization{
-		ChainID: gspec.Config.ChainID.Uint64(),
+	auth1, _ := types.SignSetCode(key1, gspec.Config.ChainID, types.SetCodeAuthorization{
 		Address: aa,
 		Nonce:   1,
 	})
-	auth2, _ := types.SignSetCode(key2, types.SetCodeAuthorization{
-		ChainID: 0,
+	auth2, _ := types.SignSetCode(key2, gspec.Config.ChainID, types.SetCodeAuthorization{
+		Unchained: true,
 		Address:   bb,
 		Nonce:     0,
 	})

core/state_transition.go

@@ -529,16 +529,12 @@ func (st *stateTransition) execute() (*ExecutionResult, error) {
 
 // validateAuthorization validates an EIP-7702 authorization against the state.
 func (st *stateTransition) validateAuthorization(auth *types.SetCodeAuthorization) (authority common.Address, err error) {
-	// Verify chain ID is 0 or equal to current chain ID.
-	if auth.ChainID != 0 && st.evm.ChainConfig().ChainID.Uint64() != auth.ChainID {
-		return authority, ErrAuthorizationWrongChainID
-	}
 	// Limit nonce to 2^64-1 per EIP-2681.
 	if auth.Nonce+1 < auth.Nonce {
 		return authority, ErrAuthorizationNonceOverflow
 	}
 	// Validate signature values and recover authority.
-	authority, err = auth.Authority()
+	authority, err = auth.Authority(st.evm.ChainConfig().ChainID)
 	if err != nil {
 		return authority, fmt.Errorf("%w: %v", ErrAuthorizationInvalidSignature, err)
 	}

core/types/gen_authorization.go

@@ -16,7 +16,7 @@ var _ = (*authorizationMarshaling)(nil)
 // MarshalJSON marshals as JSON.
 func (s SetCodeAuthorization) MarshalJSON() ([]byte, error) {
 	type SetCodeAuthorization struct {
-		ChainID hexutil.Uint64 `json:"chainId" gencodec:"required"`
+		Unchained bool           `json:"unchained" gencodec:"required"`
 		Address   common.Address `json:"address" gencodec:"required"`
 		Nonce     hexutil.Uint64 `json:"nonce" gencodec:"required"`
 		V         hexutil.Uint64 `json:"yParity" gencodec:"required"`
@@ -24,7 +24,7 @@ func (s SetCodeAuthorization) MarshalJSON() ([]byte, error) {
 		S         hexutil.U256   `json:"s" gencodec:"required"`
 	}
 	var enc SetCodeAuthorization
-	enc.ChainID = hexutil.Uint64(s.ChainID)
+	enc.Unchained = s.Unchained
 	enc.Address = s.Address
 	enc.Nonce = hexutil.Uint64(s.Nonce)
 	enc.V = hexutil.Uint64(s.V)
@@ -36,7 +36,7 @@ func (s SetCodeAuthorization) MarshalJSON() ([]byte, error) {
 // UnmarshalJSON unmarshals from JSON.
 func (s *SetCodeAuthorization) UnmarshalJSON(input []byte) error {
 	type SetCodeAuthorization struct {
-		ChainID *hexutil.Uint64 `json:"chainId" gencodec:"required"`
+		Unchained *bool           `json:"unchained" gencodec:"required"`
 		Address   *common.Address `json:"address" gencodec:"required"`
 		Nonce     *hexutil.Uint64 `json:"nonce" gencodec:"required"`
 		V         *hexutil.Uint64 `json:"yParity" gencodec:"required"`
@@ -47,10 +47,10 @@ func (s *SetCodeAuthorization) UnmarshalJSON(input []byte) error {
 	if err := json.Unmarshal(input, &dec); err != nil {
 		return err
 	}
-	if dec.ChainID == nil {
-		return errors.New("missing required field 'chainId' for SetCodeAuthorization")
+	if dec.Unchained == nil {
+		return errors.New("missing required field 'unchained' for SetCodeAuthorization")
 	}
-	s.ChainID = uint64(*dec.ChainID)
+	s.Unchained = *dec.Unchained
 	if dec.Address == nil {
 		return errors.New("missing required field 'address' for SetCodeAuthorization")
 	}

core/types/tx_setcode.go

@@ -70,7 +70,7 @@ type SetCodeTx struct {
 
 // SetCodeAuthorization is an authorization from an account to deploy code at its address.
 type SetCodeAuthorization struct {
-	ChainID uint64         `json:"chainId" gencodec:"required"`
+	Unchained bool           `json:"unchained" gencodec:"required"`
 	Address   common.Address `json:"address" gencodec:"required"`
 	Nonce     uint64         `json:"nonce" gencodec:"required"`
 	V         uint8          `json:"yParity" gencodec:"required"`
@@ -80,7 +80,6 @@ type SetCodeAuthorization struct {
 
 // field type overrides for gencodec
 type authorizationMarshaling struct {
-	ChainID hexutil.Uint64
 	Nonce hexutil.Uint64
 	V     hexutil.Uint64
 	R     hexutil.U256
@@ -88,15 +87,15 @@ type authorizationMarshaling struct {
 }
 
 // SignSetCode creates a signed the SetCode authorization.
-func SignSetCode(prv *ecdsa.PrivateKey, auth SetCodeAuthorization) (SetCodeAuthorization, error) {
-	sighash := auth.sigHash()
+func SignSetCode(prv *ecdsa.PrivateKey, chainID *big.Int, auth SetCodeAuthorization) (SetCodeAuthorization, error) {
+	sighash := auth.sigHash(chainID)
 	sig, err := crypto.Sign(sighash[:], prv)
 	if err != nil {
 		return SetCodeAuthorization{}, err
 	}
 	r, s, _ := decodeSignature(sig)
 	return SetCodeAuthorization{
-		ChainID: auth.ChainID,
+		Unchained: auth.Unchained,
 		Address:   auth.Address,
 		Nonce:     auth.Nonce,
 		V:         sig[64],
@@ -105,17 +104,25 @@ func SignSetCode(prv *ecdsa.PrivateKey, auth SetCodeAuthorization) (SetCodeAutho
 	}, nil
 }
 
-func (a *SetCodeAuthorization) sigHash() common.Hash {
+func (a *SetCodeAuthorization) sigHash(chainID *big.Int) common.Hash {
+	if a.Unchained {
+		chainID = common.Big0
+	}
 	return prefixedRlpHash(0x05, []any{
-		a.ChainID,
+		chainID,
 		a.Address,
 		a.Nonce,
 	})
 }
 
 // Authority recovers the the authorizing account of an authorization.
-func (a *SetCodeAuthorization) Authority() (common.Address, error) {
-	sighash := a.sigHash()
+func (a *SetCodeAuthorization) Authority(chainID *big.Int) (common.Address, error) {
+	if chainID == nil {
+		// This sanity check is important, since a missing chainID would just end up
+		// being encoded into the signature hash, leading to an incorrectly derived address.
+		panic("missing chainID")
+	}
+	sighash := a.sigHash(chainID)
 	if !crypto.ValidateSignatureValues(a.V, a.R.ToBig(), a.S.ToBig(), true) {
 		return common.Address{}, ErrInvalidSig
 	}