ante: EIP712 support (#950)

* code migrated

* signed_data ported to avoid conficting dependency

* correct payload

* eip712 working with evmos.me

* use geth TypedData types

* fix linter

* minor refactor

* test first try

* fix test

* fix tests

* enforce fee delegated eip712

* verify signature refactor

* SignedTypedData api refactor

* add AnteHandler test for EIP712

* remove comment

* code clean up

* return more detailed error messages

* fix linter

* remove unnecesary global vars

* Update app/ante/eip712.go

Co-authored-by: Federico Kunze Küllmer <31522760+fedekunze@users.noreply.github.com>

* fix pr comments

* remove hardcoded value

* add more tests

* add changelog

* use sdk errors

* add MsgDelegate test

Co-authored-by: Freddy Caceres <freddy.caceres@crypto.com>
Co-authored-by: Federico Kunze Küllmer <federico.kunze94@gmail.com>
Co-authored-by: Federico Kunze Küllmer <31522760+fedekunze@users.noreply.github.com>
Co-authored-by: crypto-facs <84574577+crypto-facs@users.noreply.github.com>

app/ante/utils_test.go

@@ -1,6 +1,13 @@
 package ante_test
 
 import (
+	"github.com/cosmos/cosmos-sdk/codec"
+	"github.com/cosmos/cosmos-sdk/x/auth/legacy/legacytx"
+	types2 "github.com/cosmos/cosmos-sdk/x/bank/types"
+	types3 "github.com/cosmos/cosmos-sdk/x/staking/types"
+	"github.com/ethereum/go-ethereum/crypto"
+	"github.com/tharsis/ethermint/ethereum/eip712"
+	"github.com/tharsis/ethermint/types"
 	"math"
 	"testing"
 	"time"
@@ -191,6 +198,88 @@ func (suite *AnteTestSuite) CreateTestTxBuilder(
 	return txBuilder
 }
 
+func (suite *AnteTestSuite) CreateTestEIP712TxBuilderMsgSend(from sdk.AccAddress, priv cryptotypes.PrivKey, chainId string, gas uint64, gasAmount sdk.Coins) client.TxBuilder {
+	// Build MsgSend
+	recipient := sdk.AccAddress(common.Address{}.Bytes())
+	msgSend := types2.NewMsgSend(from, recipient, sdk.NewCoins(sdk.NewCoin(evmtypes.DefaultEVMDenom, sdk.NewInt(1))))
+	return suite.CreateTestEIP712CosmosTxBuilder(from, priv, chainId, gas, gasAmount, msgSend)
+}
+
+func (suite *AnteTestSuite) CreateTestEIP712TxBuilderMsgDelegate(from sdk.AccAddress, priv cryptotypes.PrivKey, chainId string, gas uint64, gasAmount sdk.Coins) client.TxBuilder {
+	// Build MsgSend
+	valEthAddr := tests.GenerateAddress()
+	valAddr := sdk.ValAddress(valEthAddr.Bytes())
+	msgSend := types3.NewMsgDelegate(from, valAddr, sdk.NewCoin(evmtypes.DefaultEVMDenom, sdk.NewInt(20)))
+	return suite.CreateTestEIP712CosmosTxBuilder(from, priv, chainId, gas, gasAmount, msgSend)
+}
+
+func (suite *AnteTestSuite) CreateTestEIP712CosmosTxBuilder(
+	from sdk.AccAddress, priv cryptotypes.PrivKey, chainId string, gas uint64, gasAmount sdk.Coins, msg sdk.Msg,
+) client.TxBuilder {
+	var err error
+
+	nonce, err := suite.app.AccountKeeper.GetSequence(suite.ctx, from)
+	suite.Require().NoError(err)
+
+	pc, err := types.ParseChainID(chainId)
+	suite.Require().NoError(err)
+	ethChainId := pc.Uint64()
+
+	// GenerateTypedData TypedData
+	var ethermintCodec codec.ProtoCodecMarshaler
+	fee := legacytx.NewStdFee(gas, gasAmount)
+	accNumber := suite.app.AccountKeeper.GetAccount(suite.ctx, from).GetAccountNumber()
+
+	data := legacytx.StdSignBytes(chainId, accNumber, nonce, 0, fee, []sdk.Msg{msg}, "")
+	typedData, err := eip712.WrapTxToTypedData(ethermintCodec, ethChainId, msg, data, &eip712.FeeDelegationOptions{
+		FeePayer: from,
+	})
+	suite.Require().NoError(err)
+
+	sigHash, err := eip712.ComputeTypedDataHash(typedData)
+	suite.Require().NoError(err)
+
+	// Sign typedData
+	keyringSigner := tests.NewSigner(priv)
+	signature, pubKey, err := keyringSigner.SignByAddress(from, sigHash)
+	suite.Require().NoError(err)
+	signature[crypto.RecoveryIDOffset] += 27 // Transform V from 0/1 to 27/28 according to the yellow paper
+
+	// Add ExtensionOptionsWeb3Tx extension
+	var option *codectypes.Any
+	option, err = codectypes.NewAnyWithValue(&types.ExtensionOptionsWeb3Tx{
+		FeePayer:         from.String(),
+		TypedDataChainID: ethChainId,
+		FeePayerSig:      signature,
+	})
+	suite.Require().NoError(err)
+
+	suite.clientCtx.TxConfig.SignModeHandler()
+	txBuilder := suite.clientCtx.TxConfig.NewTxBuilder()
+	builder, ok := txBuilder.(authtx.ExtensionOptionsTxBuilder)
+	suite.Require().True(ok)
+
+	builder.SetExtensionOptions(option)
+	builder.SetFeeAmount(gasAmount)
+	builder.SetGasLimit(gas)
+
+	sigsV2 := signing.SignatureV2{
+		PubKey: pubKey,
+		Data: &signing.SingleSignatureData{
+			SignMode: signing.SignMode_SIGN_MODE_LEGACY_AMINO_JSON,
+		},
+		Sequence: nonce,
+	}
+
+	err = builder.SetSignatures(sigsV2)
+	suite.Require().NoError(err)
+
+	err = builder.SetMsgs(msg)
+	suite.Require().NoError(err)
+
+	return builder
+}
+
 var _ sdk.Tx = &invalidTx{}
 
 type invalidTx struct{}