Sign CCRs as EIP-712 messages (#247)

* Sign CCRs as EIP-712 messages

* Revert some changes

* brock/eip712 ccr mod (#250)

* remove chainId from EIP712 msg domain

* use verifyingContract in eip712 domain

* Rename field

---------

Co-authored-by: brock smedley <[email protected]>

core/types/confidential.go

@@ -17,6 +17,9 @@ type ConfidentialComputeRecord struct {
 	KettleAddress          common.Address
 	ConfidentialInputsHash common.Hash
 
+	// Envelope signals whether this CCR was signed using EIP-712
+	IsEIP712 bool
+
 	ChainID *big.Int
 	V, R, S *big.Int
 }
@@ -30,6 +33,7 @@ func (tx *ConfidentialComputeRecord) copy() TxData {
 		Gas:                    tx.Gas,
 		KettleAddress:          tx.KettleAddress,
 		ConfidentialInputsHash: tx.ConfidentialInputsHash,
+		IsEIP712:               tx.IsEIP712,
 
 		Value:    new(big.Int),
 		GasPrice: new(big.Int),

core/types/suave_eip712.go

@@ -0,0 +1,51 @@
+package types
+
+import (
+	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/signer/core/eip712"
+)
+
+func (msg *ConfidentialComputeRecord) EIP712Hash() (common.Hash, error) {
+	hash, _, err := eip712.TypedDataAndHash(CCREIP712Envelope(msg))
+
+	hash32 := common.Hash{}
+	copy(hash32[:], hash[:])
+
+	return hash32, err
+}
+
+func CCREIP712Envelope(msg *ConfidentialComputeRecord) eip712.TypedData {
+	return eip712.TypedData{
+		Types: eip712.Types{
+			"EIP712Domain": []eip712.Type{
+				{Name: "name", Type: "string"},
+				{Name: "verifyingContract", Type: "address"},
+			},
+			"ConfidentialRecord": []eip712.Type{
+				{Name: "nonce", Type: "uint64"},
+				{Name: "gasPrice", Type: "uint256"},
+				{Name: "gas", Type: "uint64"},
+				{Name: "to", Type: "address"},
+				{Name: "value", Type: "uint256"},
+				{Name: "data", Type: "bytes"},
+				{Name: "kettleAddress", Type: "address"},
+				{Name: "confidentialInputsHash", Type: "bytes32"},
+			},
+		},
+		Domain: eip712.TypedDataDomain{
+			Name:              "ConfidentialRecord",
+			VerifyingContract: msg.KettleAddress.Hex(),
+		},
+		PrimaryType: "ConfidentialRecord",
+		Message: eip712.TypedDataMessage{
+			"nonce":                  msg.Nonce,
+			"gasPrice":               msg.GasPrice,
+			"gas":                    msg.Gas,
+			"to":                     msg.To,
+			"value":                  msg.Value,
+			"data":                   msg.Data,
+			"kettleAddress":          msg.KettleAddress,
+			"confidentialInputsHash": msg.ConfidentialInputsHash,
+		},
+	}
+}

core/types/suave_eip712_test.go

@@ -0,0 +1,23 @@
+package types
+
+import (
+	"math/big"
+	"testing"
+
+	"github.com/ethereum/go-ethereum/common"
+	"github.com/stretchr/testify/require"
+)
+
+func TestCCREIP712(t *testing.T) {
+	to := common.Address{0x2}
+
+	ccr := &ConfidentialComputeRecord{
+		GasPrice: big.NewInt(0),
+		To:       &to,
+		Value:    big.NewInt(0),
+		ChainID:  big.NewInt(0),
+	}
+
+	_, err := ccr.EIP712Hash()
+	require.NoError(t, err)
+}

core/types/transaction_marshalling.go

@@ -44,6 +44,7 @@ type txJSON struct {
 	BlobVersionedHashes       []common.Hash    `json:"blobVersionedHashes,omitempty"`
 	KettleAddress             *common.Address  `json:"kettleAddress,omitempty"`
 	ConfidentialInputsHash    *common.Hash     `json:"confidentialInputsHash,omitempty"`
+	IsEIP712                  *bool            `json:"iseip712,omitempty"`
 	ConfidentialInputs        *hexutil.Bytes   `json:"confidentialInputs,omitempty"`
 	RequestRecord             *json.RawMessage `json:"requestRecord,omitempty"`
 	ConfidentialComputeResult *hexutil.Bytes   `json:"confidentialComputeResult,omitempty"`
@@ -146,6 +147,7 @@ func (tx *Transaction) MarshalJSON() ([]byte, error) {
 		enc.V = (*hexutil.Big)(itx.V)
 		enc.R = (*hexutil.Big)(itx.R)
 		enc.S = (*hexutil.Big)(itx.S)
+		enc.IsEIP712 = &itx.IsEIP712
 
 	case *SuaveTransaction:
 		requestRecord, err := NewTx(&itx.ConfidentialComputeRequest).MarshalJSON()
@@ -498,6 +500,9 @@ func (tx *Transaction) UnmarshalJSON(input []byte) error {
 			return errors.New("missing required field 'chainId' in transaction")
 		}
 		itx.ChainID = (*big.Int)(dec.ChainID)
+		if dec.IsEIP712 != nil {
+			itx.IsEIP712 = *dec.IsEIP712
+		}
 		if dec.V == nil {
 			return errors.New("missing required field 'r' in transaction")
 		}

core/types/transaction_signing.go

@@ -24,6 +24,7 @@ import (
 
 	"github.com/ethereum/go-ethereum/common"
 	"github.com/ethereum/go-ethereum/crypto"
+	"github.com/ethereum/go-ethereum/log"
 	"github.com/ethereum/go-ethereum/params"
 )
 
@@ -358,6 +359,15 @@ func (s suaveSigner) Hash(tx *Transaction) common.Hash {
 				txdata.ConfidentialComputeResult,
 			})
 	case *ConfidentialComputeRequest:
+		if txdata.IsEIP712 {
+			// EIP-712 signature used during signing
+			hash, err := txdata.ConfidentialComputeRecord.EIP712Hash()
+			if err != nil {
+				log.Error("failed to calculate EIP712 hash", "err", err)
+			}
+			return hash
+		}
+
 		return prefixedRlpHash(
 			ConfidentialComputeRecordTxType, // Note: this is the same as the Record so that hashes match!
 			[]interface{}{
@@ -371,6 +381,16 @@ func (s suaveSigner) Hash(tx *Transaction) common.Hash {
 				tx.Data(),
 			})
 	case *ConfidentialComputeRecord:
+		if txdata.IsEIP712 {
+			// EIP-712 signature using during recovery
+			hash, err := txdata.EIP712Hash()
+			if err != nil {
+				log.Error("failed to calculate EIP712 hash", "err", err)
+			}
+			return hash
+		}
+
+		// normal txn signature
 		return prefixedRlpHash(
 			tx.Type(),
 			[]interface{}{
@@ -689,6 +709,10 @@ func (fs FrontierSigner) Hash(tx *Transaction) common.Hash {
 	})
 }
 
+func DecodeSignature(sig []byte) (r, s, v *big.Int) {
+	return decodeSignature(sig)
+}
+
 func decodeSignature(sig []byte) (r, s, v *big.Int) {
 	if len(sig) != crypto.SignatureLength {
 		panic(fmt.Sprintf("wrong size for signature: got %d, want %d", len(sig), crypto.SignatureLength))