types: unmarshal account from hex address (#504)

* types: unmarshal account from hex address:

* changelog

CHANGELOG.md

@@ -43,6 +43,7 @@ Ref: https://keepachangelog.com/en/1.0.0/
 
 ### Improvements
 
+* (types) [\#504](https://github.com/ChainSafe/ethermint/pull/504) Unmarshal a JSON `EthAccount` using an Ethereum hex address in addition to Bech32.
 * (types) [\#503](https://github.com/ChainSafe/ethermint/pull/503) Add `--coin-denom` flag to testnet command that sets the given coin denomination to SDK and Ethermint parameters.
 * (types) [\#502](https://github.com/ChainSafe/ethermint/pull/502) `EthAccount` now also exposes the Ethereum hex address in `string` format to clients.
 * (types) [\#494](https://github.com/ChainSafe/ethermint/pull/494) Update `EthAccount` public key JSON type to `string`.

types/account.go

@@ -1,12 +1,14 @@
 package types
 
 import (
+	"bytes"
 	"encoding/json"
 	"fmt"
 
 	"gopkg.in/yaml.v2"
 
 	sdk "github.com/cosmos/cosmos-sdk/types"
+	sdkerrors "github.com/cosmos/cosmos-sdk/types/errors"
 	"github.com/cosmos/cosmos-sdk/x/auth"
 	"github.com/cosmos/cosmos-sdk/x/auth/exported"
 	authtypes "github.com/cosmos/cosmos-sdk/x/auth/types"
@@ -114,9 +116,15 @@ func (acc EthAccount) MarshalYAML() (interface{}, error) {
 
 // MarshalJSON returns the JSON representation of an EthAccount.
 func (acc EthAccount) MarshalJSON() ([]byte, error) {
+	var ethAddress = ""
+
+	if acc.BaseAccount != nil && acc.Address != nil {
+		ethAddress = acc.EthAddress().String()
+	}
+
 	alias := ethermintAccountPretty{
 		Address:       acc.Address,
-		EthAddress:    acc.EthAddress().String(),
+		EthAddress:    ethAddress,
 		Coins:         acc.Coins,
 		AccountNumber: acc.AccountNumber,
 		Sequence:      acc.Sequence,
@@ -146,6 +154,37 @@ func (acc *EthAccount) UnmarshalJSON(bz []byte) error {
 		return err
 	}
 
+	switch {
+	case !alias.Address.Empty() && alias.EthAddress != "":
+		// Both addresses provided. Verify correctness
+		ethAddress := ethcmn.HexToAddress(alias.EthAddress)
+		ethAddressFromAccAddress := ethcmn.BytesToAddress(alias.Address.Bytes())
+
+		if !bytes.Equal(ethAddress.Bytes(), alias.Address.Bytes()) {
+			err = sdkerrors.Wrapf(
+				sdkerrors.ErrInvalidAddress,
+				"expected %s, got %s",
+				ethAddressFromAccAddress.String(), ethAddress.String(),
+			)
+		}
+
+	case !alias.Address.Empty() && alias.EthAddress == "":
+		// unmarshal sdk.AccAddress only. Do nothing here
+	case alias.Address.Empty() && alias.EthAddress != "":
+		// retrieve sdk.AccAddress from ethereum address
+		ethAddress := ethcmn.HexToAddress(alias.EthAddress)
+		alias.Address = sdk.AccAddress(ethAddress.Bytes())
+	case alias.Address.Empty() && alias.EthAddress == "":
+		err = sdkerrors.Wrapf(
+			sdkerrors.ErrInvalidAddress,
+			"account must contain address in Ethereum Hex or Cosmos Bech32 format",
+		)
+	}
+
+	if err != nil {
+		return err
+	}
+
 	acc.BaseAccount = &authtypes.BaseAccount{
 		Coins:         alias.Coins,
 		Address:       alias.Address,

types/account_test.go

@@ -7,12 +7,12 @@ import (
 
 	"github.com/stretchr/testify/require"
 
-	sdk "github.com/cosmos/cosmos-sdk/types"
-	"github.com/cosmos/cosmos-sdk/x/auth"
-
 	tmamino "github.com/tendermint/tendermint/crypto/encoding/amino"
 	"github.com/tendermint/tendermint/crypto/secp256k1"
 
+	sdk "github.com/cosmos/cosmos-sdk/types"
+	"github.com/cosmos/cosmos-sdk/x/auth"
+
 	emintcrypto "github.com/cosmos/ethermint/crypto"
 )
 
@@ -106,9 +106,43 @@ func TestEthermintAccount_MarshalJSON(t *testing.T) {
 
 	bz, err := ethAcc.MarshalJSON()
 	require.NoError(t, err)
+	require.Contains(t, string(bz), ethAcc.EthAddress().String())
 
 	res := new(EthAccount)
 	err = res.UnmarshalJSON(bz)
 	require.NoError(t, err)
 	require.Equal(t, ethAcc, res)
+
+	bech32pubkey, err := sdk.Bech32ifyPubKey(sdk.Bech32PubKeyTypeAccPub, pubkey)
+	require.NoError(t, err)
+
+	// test that the sdk.AccAddress is populated from the hex address
+	jsonAcc := fmt.Sprintf(
+		`{"address":"","eth_address":"%s","coins":[{"denom":"aphoton","amount":"1"}],"public_key":"%s","account_number":10,"sequence":50,"code_hash":"0102"}`,
+		ethAcc.EthAddress().String(), bech32pubkey,
+	)
+
+	res = new(EthAccount)
+	err = res.UnmarshalJSON([]byte(jsonAcc))
+	require.NoError(t, err)
+	require.Equal(t, addr.String(), res.Address.String())
+
+	jsonAcc = fmt.Sprintf(
+		`{"address":"","eth_address":"","coins":[{"denom":"aphoton","amount":"1"}],"public_key":"%s","account_number":10,"sequence":50,"code_hash":"0102"}`,
+		bech32pubkey,
+	)
+
+	res = new(EthAccount)
+	err = res.UnmarshalJSON([]byte(jsonAcc))
+	require.Error(t, err, "should fail if both address are empty")
+
+	// test that the sdk.AccAddress is populated from the hex address
+	jsonAcc = fmt.Sprintf(
+		`{"address": "%s","eth_address":"0x0000000000000000000000000000000000000000","coins":[{"denom":"aphoton","amount":"1"}],"public_key":"%s","account_number":10,"sequence":50,"code_hash":"0102"}`,
+		ethAcc.Address.String(), bech32pubkey,
+	)
+
+	res = new(EthAccount)
+	err = res.UnmarshalJSON([]byte(jsonAcc))
+	require.Error(t, err, "should fail if addresses mismatch")
 }