add eip191 signmode support

follow cosmos/gogoproto#83

client/tx/tx.go

@@ -261,6 +261,8 @@ func Sign(ctx context.Context, txf Factory, name string, txBuilder client.TxBuil
 		if err != nil {
 			return err
 		}
+	} else if signMode == signing.SignMode_SIGN_MODE_EIP_191 {
+		return fmt.Errorf("EIP191 signing is not supported in cli")
 	}
 
 	k, err := txf.keybase.Key(name)

crypto/keys/secp256k1/secp256k1_cgo.go

@@ -5,6 +5,7 @@ package secp256k1
 
 import (
 	"github.com/cometbft/cometbft/crypto"
+	"golang.org/x/crypto/sha3"
 
 	"github.com/cosmos/cosmos-sdk/crypto/keys/secp256k1/internal/secp256k1"
 )
@@ -25,3 +26,15 @@ func (privKey *PrivKey) Sign(msg []byte) ([]byte, error) {
 func (pubKey *PubKey) VerifySignature(msg, sigStr []byte) bool {
 	return secp256k1.VerifySignature(pubKey.Bytes(), crypto.Sha256(msg), sigStr)
 }
+
+// VerifySignatureEIP191 validates the signature.
+// The msg will be hashed prior to signature verification.
+func (pubKey *PubKey) VerifySignatureEIP191(msg []byte, sigStr []byte) bool {
+	return secp256k1.VerifySignature(pubKey.Bytes(), keccak256(msg), sigStr)
+}
+
+func keccak256(bytes []byte) []byte {
+	hasher := sha3.NewLegacyKeccak256()
+	hasher.Write(bytes)
+	return hasher.Sum(nil)
+}

crypto/keys/secp256k1/secp256k1_nocgo.go

@@ -6,6 +6,8 @@ package secp256k1
 import (
 	"errors"
 
+	"golang.org/x/crypto/sha3"
+
 	"github.com/cometbft/cometbft/crypto"
 	secp256k1 "github.com/decred/dcrd/dcrec/secp256k1/v4"
 	"github.com/decred/dcrd/dcrec/secp256k1/v4/ecdsa"
@@ -39,6 +41,24 @@ func (pubKey *PubKey) VerifySignature(msg, sigStr []byte) bool {
 	return signature.Verify(crypto.Sha256(msg), pub)
 }
 
+// VerifySignatureEIP191 verifies a signature of the form R || S.
+// It rejects signatures which are not in lower-S form.
+func (pubKey *PubKey) VerifySignatureEIP191(msg []byte, sigStr []byte) bool {
+	if len(sigStr) != 64 {
+		return false
+	}
+	pub, err := secp256k1.ParsePubKey(pubKey.Key)
+	if err != nil {
+		return false
+	}
+	// parse the signature, will return error if it is not in lower-S form
+	signature, err := signatureFromBytes(sigStr)
+	if err != nil {
+		return false
+	}
+	return signature.Verify(keccak256(msg), pub)
+}
+
 // Read Signature struct from R || S. Caller needs to ensure
 // that len(sigStr) == 64.
 // Rejects malleable signatures (if S value if it is over half order).
@@ -53,3 +73,9 @@ func signatureFromBytes(sigStr []byte) (*ecdsa.Signature, error) {
 
 	return ecdsa.NewSignature(&r, &s), nil
 }
+
+func keccak256(bytes []byte) []byte {
+	hasher := sha3.NewLegacyKeccak256()
+	hasher.Write(bytes)
+	return hasher.Sum(nil)
+}

x/auth/signing/verify.go

@@ -2,10 +2,12 @@ package signing
 
 import (
 	"context"
+	"encoding/hex"
 	"fmt"
 
 	signingv1beta1 "cosmossdk.io/api/cosmos/tx/signing/v1beta1"
 	txsigning "cosmossdk.io/x/tx/signing"
+	"github.com/cosmos/cosmos-sdk/crypto/keys/secp256k1"
 
 	cryptotypes "github.com/cosmos/cosmos-sdk/crypto/types"
 	"github.com/cosmos/cosmos-sdk/crypto/types/multisig"
@@ -77,9 +79,20 @@ func VerifySignature(
 		if err != nil {
 			return err
 		}
-		if !pubKey.VerifySignature(signBytes, data.Signature) {
+
+		if data.SignMode == signing.SignMode_SIGN_MODE_EIP_191 {
+			secp256k1PubKey, ok := pubKey.(*secp256k1.PubKey)
+			if !ok {
+				return fmt.Errorf("eip191 sign mode requires pubkey to be of type cosmos.crypto.secp256k1.PubKey")
+			}
+
+			if !secp256k1PubKey.VerifySignatureEIP191(signBytes, data.Signature) {
+				return fmt.Errorf("unable to verify single signer eip191 signature %s for signBytes %s", hex.EncodeToString(data.Signature), hex.EncodeToString(signBytes))
+			}
+		} else if !pubKey.VerifySignature(signBytes, data.Signature) {
 			return fmt.Errorf("unable to verify single signer signature")
 		}
+
 		return nil
 
 	case *signing.MultiSignatureData:

x/auth/tx/config.go

@@ -61,6 +61,7 @@ var DefaultSignModes = []signingtypes.SignMode{
 	signingtypes.SignMode_SIGN_MODE_DIRECT,
 	signingtypes.SignMode_SIGN_MODE_DIRECT_AUX,
 	signingtypes.SignMode_SIGN_MODE_LEGACY_AMINO_JSON,
+	signingtypes.SignMode_SIGN_MODE_EIP_191,
 	// signingtypes.SignMode_SIGN_MODE_TEXTUAL is not enabled by default, as it requires a x/bank keeper or gRPC connection.
 }
 
@@ -152,6 +153,11 @@ func NewSigningHandlerMap(configOpts ConfigOptions) (*txsigning.HandlerMap, erro
 			if err != nil {
 				return nil, err
 			}
+		case signingtypes.SignMode_SIGN_MODE_EIP_191:
+			handlers[i] = NewSignModeEIP191Handler(aminojson.SignModeHandlerOptions{
+				FileResolver: signingOpts.FileResolver,
+				TypeResolver: signingOpts.TypeResolver,
+			})
 		}
 	}
 	for i, m := range configOpts.CustomSignModes {

x/auth/tx/eip191.go

@@ -0,0 +1,48 @@
+package tx
+
+import (
+	"context"
+	"strconv"
+
+	signingv1beta1 "cosmossdk.io/api/cosmos/tx/signing/v1beta1"
+	"cosmossdk.io/x/tx/signing"
+	"cosmossdk.io/x/tx/signing/aminojson"
+)
+
+const EIP191MessagePrefix = "\x19Ethereum Signed Message:\n"
+
+const eip191NonCriticalFieldsError = "protobuf transaction contains unknown non-critical fields. This is a transaction malleability issue and SIGN_MODE_EIP_191 cannot be used."
+
+// SignModeEIP191Handler defines the SIGN_MODE_DIRECT SignModeHandler
+type SignModeEIP191Handler struct {
+	*aminojson.SignModeHandler
+}
+
+// NewSignModeEIP191Handler returns a new SignModeEIP191Handler.
+func NewSignModeEIP191Handler(options aminojson.SignModeHandlerOptions) *SignModeEIP191Handler {
+	return &SignModeEIP191Handler{
+		SignModeHandler: aminojson.NewSignModeHandler(options),
+	}
+}
+
+var _ signing.SignModeHandler = SignModeEIP191Handler{}
+
+// Mode implements signing.SignModeHandler.Mode.
+func (SignModeEIP191Handler) Mode() signingv1beta1.SignMode {
+	return signingv1beta1.SignMode_SIGN_MODE_EIP_191
+}
+
+// GetSignBytes implements SignModeHandler.GetSignBytes
+func (h SignModeEIP191Handler) GetSignBytes(
+	ctx context.Context, data signing.SignerData, txData signing.TxData,
+) ([]byte, error) {
+	aminoJSONBz, err := h.SignModeHandler.GetSignBytes(ctx, data, txData)
+	if err != nil {
+		return nil, err
+	}
+
+	return append(append(
+		[]byte(EIP191MessagePrefix),
+		[]byte(strconv.Itoa(len(aminoJSONBz)))...,
+	), aminoJSONBz...), nil
+}