update web3 transaction hash from RLP (#250)

* remove ethereum hash of web3 transaction type (always amino hash)

* Update changelog

CHANGELOG.md

@@ -51,7 +51,7 @@ Ref: https://keepachangelog.com/en/1.0.0/
   * (keys) Marked `ExportEthKeyCommand` as **UNSAFE**
   * (x/evm) Moved `BeginBlock` and `EndBlock` to `x/evm/abci.go`
 
-## Features
+### Features
 
 * (rpc) [\#231](https://github.com/ChainSafe/ethermint/issues/231) Implement NewBlockFilter in rpc/filters.go which instantiates a polling block filter
 	* Polls for new blocks via BlockNumber rpc call; if block number changes, it requests the new block via GetBlockByNumber rpc call and adds it to its internal list of blocks
@@ -64,3 +64,8 @@ Ref: https://keepachangelog.com/en/1.0.0/
   * for a given filter, look through each block for transactions. If there are transactions in the block, get the logs from it, and filter using the filterLogs method
   * eth_getLogs and eth_getFilterChanges for log filters use the same underlying method as eth_getFilterLogs
   * update HandleMsgEthereumTx to store logs using the ethereum hash
+
+### Bug Fixes
+
+* (x/evm) [\#176](https://github.com/ChainSafe/ethermint/issues/176) Updated Web3 transaction hash from using RLP hash. Now all transaction hashes exposed are amino hashes.
+  * Removes `Hash()` (RLP) function from `MsgEthereumTx` to avoid confusion or misuse in future.

rpc/backend.go

@@ -188,7 +188,7 @@ func (e *EthermintBackend) PendingTransactions() ([]*Transaction, error) {
 		}
 
 		// * Should check signer and reference against accounts the node manages in future
-		rpcTx, err := newRPCTransaction(*ethTx, common.Hash{}, nil, 0)
+		rpcTx, err := newRPCTransaction(*ethTx, common.BytesToHash(tx.Hash()), common.Hash{}, nil, 0)
 		if err != nil {
 			return nil, err
 		}

rpc/eth_api.go

@@ -514,7 +514,7 @@ func convertTransactionsToRPC(cliCtx context.CLIContext, txs []tmtypes.Tx, block
 		}
 		// TODO: Remove gas usage calculation if saving gasUsed per block
 		gasUsed.Add(gasUsed, ethTx.Fee())
-		tx, err := newRPCTransaction(*ethTx, blockHash, &height, uint64(i))
+		tx, err := newRPCTransaction(*ethTx, common.BytesToHash(tx.Hash()), blockHash, &height, uint64(i))
 		if err != nil {
 			return nil, nil, err
 		}
@@ -558,7 +558,7 @@ func bytesToEthTx(cliCtx context.CLIContext, bz []byte) (*types.MsgEthereumTx, e
 
 // newRPCTransaction returns a transaction that will serialize to the RPC
 // representation, with the given location metadata set (if available).
-func newRPCTransaction(tx types.MsgEthereumTx, blockHash common.Hash, blockNumber *uint64, index uint64) (*Transaction, error) {
+func newRPCTransaction(tx types.MsgEthereumTx, txHash, blockHash common.Hash, blockNumber *uint64, index uint64) (*Transaction, error) {
 	// Verify signature and retrieve sender address
 	from, err := tx.VerifySig(tx.ChainID())
 	if err != nil {
@@ -569,7 +569,7 @@ func newRPCTransaction(tx types.MsgEthereumTx, blockHash common.Hash, blockNumbe
 		From:     from,
 		Gas:      hexutil.Uint64(tx.Data.GasLimit),
 		GasPrice: (*hexutil.Big)(tx.Data.Price),
-		Hash:     tx.Hash(),
+		Hash:     txHash,
 		Input:    hexutil.Bytes(tx.Data.Payload),
 		Nonce:    hexutil.Uint64(tx.Data.AccountNonce),
 		To:       tx.To(),
@@ -609,7 +609,7 @@ func (e *PublicEthAPI) GetTransactionByHash(hash common.Hash) (*Transaction, err
 	}
 
 	height := uint64(tx.Height)
-	return newRPCTransaction(*ethTx, blockHash, &height, uint64(tx.Index))
+	return newRPCTransaction(*ethTx, common.BytesToHash(tx.Tx.Hash()), blockHash, &height, uint64(tx.Index))
 }
 
 // GetTransactionByBlockHashAndIndex returns the transaction identified by hash and index.
@@ -647,7 +647,7 @@ func (e *PublicEthAPI) getTransactionByBlockNumberAndIndex(number int64, idx hex
 	}
 
 	height := uint64(header.Height)
-	return newRPCTransaction(*ethTx, common.BytesToHash(header.Hash()), &height, uint64(idx))
+	return newRPCTransaction(*ethTx, common.BytesToHash(txs[idx].Hash()), common.BytesToHash(header.Hash()), &height, uint64(idx))
 }
 
 // GetTransactionReceipt returns the transaction receipt identified by hash.

x/evm/handler.go

@@ -43,7 +43,8 @@ func HandleMsgEthereumTx(ctx sdk.Context, k Keeper, msg types.MsgEthereumTx) sdk
 		return sdk.ResultFromError(err)
 	}
 
-	txHash := msg.Hash()
+	txHash := tmtypes.Tx(ctx.TxBytes()).Hash()
+	ethHash := common.BytesToHash(txHash)
 
 	st := types.StateTransition{
 		Sender:       sender,
@@ -55,12 +56,13 @@ func HandleMsgEthereumTx(ctx sdk.Context, k Keeper, msg types.MsgEthereumTx) sdk
 		Payload:      msg.Data.Payload,
 		Csdb:         k.CommitStateDB.WithContext(ctx),
 		ChainID:      intChainID,
-		THash:        &txHash,
+		THash:        &ethHash,
 		Simulate:     ctx.IsCheckTx(),
 	}
+
 	// Prepare db for logs
 	// TODO: block hash
-	k.CommitStateDB.Prepare(txHash, txHash, k.TxCount)
+	k.CommitStateDB.Prepare(ethHash, common.Hash{}, k.TxCount)
 	k.TxCount++
 
 	// TODO: move to keeper

x/evm/types/msg.go

@@ -198,18 +198,6 @@ func (msg *MsgEthereumTx) DecodeRLP(s *rlp.Stream) error {
 	return err
 }
 
-// Hash hashes the RLP encoding of a transaction.
-func (msg *MsgEthereumTx) Hash() ethcmn.Hash {
-	if hash := msg.hash.Load(); hash != nil {
-		return hash.(ethcmn.Hash)
-	}
-
-	v := rlpHash(msg)
-	msg.hash.Store(v)
-
-	return v
-}
-
 // Sign calculates a secp256k1 ECDSA signature and signs the transaction. It
 // takes a private key and chainID to sign an Ethereum transaction according to
 // EIP155 standard. It mutates the transaction as it populates the V, R, S

x/evm/types/msg_test.go

@@ -89,14 +89,6 @@ func TestMsgEthereumTxRLPDecode(t *testing.T) {
 	require.Equal(t, expectedMsg.Data, msg.Data)
 }
 
-func TestMsgEthereumTxHash(t *testing.T) {
-	addr := ethcmn.BytesToAddress([]byte("test_address"))
-	msg := NewMsgEthereumTx(0, &addr, nil, 100000, nil, []byte("test"))
-
-	hash := msg.Hash()
-	require.Equal(t, "E2AA2E68E7586AE9700F1D3D643330866B6AC2B6CA4C804F7C85ECB11D0B0B29", fmt.Sprintf("%X", hash))
-}
-
 func TestMsgEthereumTxSig(t *testing.T) {
 	chainID := big.NewInt(3)