crypto: refactor for stargate (#559)

* changelog

* update changelog

* crypto: refactor for stargate

* fixes

* fix keys

* changelog

app/ante/ante.go

@@ -8,14 +8,14 @@ import (
 	"github.com/cosmos/cosmos-sdk/x/auth/keeper"
 	"github.com/cosmos/cosmos-sdk/x/auth/types"
 
-	"github.com/cosmos/ethermint/crypto"
+	"github.com/cosmos/ethermint/crypto/ethsecp256k1"
 	evmtypes "github.com/cosmos/ethermint/x/evm/types"
 
 	tmcrypto "github.com/tendermint/tendermint/crypto"
 )
 
 func init() {
-	crypto.RegisterCodec(types.ModuleCdc)
+	ethsecp256k1.RegisterCodec(types.ModuleCdc)
 }
 
 const (
@@ -76,7 +76,7 @@ func sigGasConsumer(
 	meter sdk.GasMeter, _ []byte, pubkey tmcrypto.PubKey, _ types.Params,
 ) error {
 	switch pubkey.(type) {
-	case crypto.PubKeySecp256k1:
+	case ethsecp256k1.PubKey:
 		meter.ConsumeGas(secp256k1VerifyCost, "ante verify: secp256k1")
 		return nil
 	case tmcrypto.PubKey:

app/ante/utils_test.go

@@ -12,7 +12,7 @@ import (
 
 	"github.com/cosmos/ethermint/app"
 	ante "github.com/cosmos/ethermint/app/ante"
-	"github.com/cosmos/ethermint/crypto"
+	"github.com/cosmos/ethermint/crypto/ethsecp256k1"
 	ethermint "github.com/cosmos/ethermint/types"
 	evmtypes "github.com/cosmos/ethermint/x/evm/types"
 
@@ -60,7 +60,7 @@ func newTestStdFee() auth.StdFee {
 
 // GenerateAddress generates an Ethereum address.
 func newTestAddrKey() (sdk.AccAddress, tmcrypto.PrivKey) {
-	privkey, _ := crypto.GenerateKey()
+	privkey, _ := ethsecp256k1.GenerateKey()
 	addr := ethcrypto.PubkeyToAddress(privkey.ToECDSA().PublicKey)
 
 	return sdk.AccAddress(addr.Bytes()), privkey
@@ -95,7 +95,7 @@ func newTestEthTx(ctx sdk.Context, msg evmtypes.MsgEthereumTx, priv tmcrypto.Pri
 		return nil, err
 	}
 
-	privkey, ok := priv.(crypto.PrivKeySecp256k1)
+	privkey, ok := priv.(ethsecp256k1.PrivKey)
 	if !ok {
 		return nil, fmt.Errorf("invalid private key type: %T", priv)
 	}