Transaction signing and encoding (#95)

* WIP setting up evm tx command and updating emint keys output

* Fix linting issue

* Wip restructuring to allow for ethereum signing and encoding

* WIP setting up keybase and context to use Ethermint keys

* Fixed encoding and decoding of emint keys

* Adds command for generating explicit ethereum tx

* Fixed evm route for handling tx

* Fixed tx and msg encoding which allows transactions to be sent

* Added relevant documentation for changes and cleaned up code

* Added documentation and indicators why code was overriden
This commit is contained in:
Austin Abell
2019-09-15 12:12:59 -04:00
committed by GitHub
parent 4c29c48905
commit 72fc3ca3af
20 changed files with 1070 additions and 66 deletions
+135
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@@ -0,0 +1,135 @@
package cli
import (
"math/big"
"strconv"
"github.com/spf13/cobra"
"github.com/cosmos/cosmos-sdk/client"
"github.com/cosmos/cosmos-sdk/codec"
sdk "github.com/cosmos/cosmos-sdk/types"
"github.com/cosmos/cosmos-sdk/x/auth"
"github.com/cosmos/cosmos-sdk/x/auth/client/utils"
emintkeys "github.com/cosmos/ethermint/keys"
emintTypes "github.com/cosmos/ethermint/types"
emintUtils "github.com/cosmos/ethermint/x/evm/client/utils"
"github.com/cosmos/ethermint/x/evm/types"
ethcmn "github.com/ethereum/go-ethereum/common"
)
// GetTxCmd defines the CLI commands regarding evm module transactions
func GetTxCmd(storeKey string, cdc *codec.Codec) *cobra.Command {
evmTxCmd := &cobra.Command{
Use: types.ModuleName,
Short: "EVM transaction subcommands",
DisableFlagParsing: true,
SuggestionsMinimumDistance: 2,
RunE: client.ValidateCmd,
}
evmTxCmd.AddCommand(client.PostCommands(
// TODO: Add back generating cosmos tx for Ethereum tx message
// GetCmdGenTx(cdc),
GetCmdGenETHTx(cdc),
)...)
return evmTxCmd
}
// GetCmdGenTx generates an ethereum transaction wrapped in a Cosmos standard transaction
func GetCmdGenTx(cdc *codec.Codec) *cobra.Command {
return &cobra.Command{
Use: "generate-tx [ethaddress] [amount] [gaslimit] [gasprice] [payload]",
Short: "generate eth tx wrapped in a Cosmos Standard tx",
Args: cobra.ExactArgs(5),
RunE: func(cmd *cobra.Command, args []string) error {
// TODO: remove inputs and infer based on StdTx
cliCtx := emintUtils.NewETHCLIContext().WithCodec(cdc)
txBldr := auth.NewTxBuilderFromCLI().WithTxEncoder(utils.GetTxEncoder(cdc))
kb, err := emintkeys.NewKeyBaseFromHomeFlag()
if err != nil {
panic(err)
}
coins, err := sdk.ParseCoins(args[1])
if err != nil {
return err
}
gasLimit, err := strconv.ParseUint(args[2], 0, 64)
if err != nil {
return err
}
gasPrice, err := strconv.ParseUint(args[3], 0, 64)
if err != nil {
return err
}
payload := args[4]
// TODO: Remove explicit photon check and check variables
msg := types.NewEthereumTxMsg(0, ethcmn.HexToAddress(args[0]), big.NewInt(coins.AmountOf(emintTypes.DenomDefault).Int64()), gasLimit, new(big.Int).SetUint64(gasPrice), []byte(payload))
err = msg.ValidateBasic()
if err != nil {
return err
}
// TODO: possibly overwrite gas values in txBldr
return emintUtils.GenerateOrBroadcastETHMsgs(cliCtx, txBldr.WithKeybase(kb), []sdk.Msg{msg})
},
}
}
// GetCmdGenTx generates an ethereum transaction
func GetCmdGenETHTx(cdc *codec.Codec) *cobra.Command {
return &cobra.Command{
Use: "generate-eth-tx [nonce] [ethaddress] [amount] [gaslimit] [gasprice] [payload]",
Short: "geberate and broadcast an Ethereum tx",
Args: cobra.ExactArgs(6),
RunE: func(cmd *cobra.Command, args []string) error {
cliCtx := emintUtils.NewETHCLIContext().WithCodec(cdc)
txBldr := auth.NewTxBuilderFromCLI().WithTxEncoder(utils.GetTxEncoder(cdc))
kb, err := emintkeys.NewKeyBaseFromHomeFlag()
if err != nil {
panic(err)
}
nonce, err := strconv.ParseUint(args[0], 0, 64)
if err != nil {
return err
}
coins, err := sdk.ParseCoins(args[2])
if err != nil {
return err
}
gasLimit, err := strconv.ParseUint(args[3], 0, 64)
if err != nil {
return err
}
gasPrice, err := strconv.ParseUint(args[4], 0, 64)
if err != nil {
return err
}
payload := args[5]
tx := types.NewEthereumTxMsg(nonce, ethcmn.HexToAddress(args[1]), big.NewInt(coins.AmountOf(emintTypes.DenomDefault).Int64()), gasLimit, new(big.Int).SetUint64(gasPrice), []byte(payload))
err = tx.ValidateBasic()
if err != nil {
return err
}
return emintUtils.BroadcastETHTx(cliCtx, txBldr.WithSequence(nonce).WithKeybase(kb), tx)
},
}
}
+348
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@@ -0,0 +1,348 @@
package utils
import (
"bufio"
"fmt"
"math/big"
"os"
"github.com/pkg/errors"
"github.com/spf13/viper"
"github.com/cosmos/cosmos-sdk/client/context"
"github.com/cosmos/cosmos-sdk/client/flags"
"github.com/cosmos/cosmos-sdk/client/input"
crkeys "github.com/cosmos/cosmos-sdk/crypto/keys"
sdk "github.com/cosmos/cosmos-sdk/types"
"github.com/cosmos/cosmos-sdk/x/auth/client/utils"
authtypes "github.com/cosmos/cosmos-sdk/x/auth/types"
emintcrypto "github.com/cosmos/ethermint/crypto"
emintkeys "github.com/cosmos/ethermint/keys"
emint "github.com/cosmos/ethermint/types"
evmtypes "github.com/cosmos/ethermint/x/evm/types"
"github.com/tendermint/tendermint/libs/cli"
rpcclient "github.com/tendermint/tendermint/rpc/client"
)
// * Code from this file is a modified version of cosmos-sdk/auth/client/utils/tx.go
// * to allow for using the Ethermint keybase for signing the transaction
// GenerateOrBroadcastMsgs creates a StdTx given a series of messages. If
// the provided context has generate-only enabled, the tx will only be printed
// to STDOUT in a fully offline manner. Otherwise, the tx will be signed and
// broadcasted.
func GenerateOrBroadcastETHMsgs(cliCtx context.CLIContext, txBldr authtypes.TxBuilder, msgs []sdk.Msg) error {
if cliCtx.GenerateOnly {
return utils.PrintUnsignedStdTx(txBldr, cliCtx, msgs)
}
return completeAndBroadcastETHTxCLI(txBldr, cliCtx, msgs)
}
// BroadcastETHTx Broadcasts an Ethereum Tx not wrapped in a Std Tx
func BroadcastETHTx(cliCtx context.CLIContext, txBldr authtypes.TxBuilder, tx *evmtypes.EthereumTxMsg) error {
txBldr, err := utils.PrepareTxBuilder(txBldr, cliCtx)
if err != nil {
return err
}
fromName := cliCtx.GetFromName()
passphrase, err := emintkeys.GetPassphrase(fromName)
if err != nil {
return err
}
// Sign V, R, S fields for tx
ethTx, err := signEthTx(txBldr.Keybase(), fromName, passphrase, tx, txBldr.ChainID())
if err != nil {
return err
}
// Use default Tx Encoder since it will just be broadcasted to TM node at this point
txEncoder := txBldr.TxEncoder()
txBytes, err := txEncoder(ethTx)
if err != nil {
return err
}
// broadcast to a Tendermint node
res, err := cliCtx.BroadcastTx(txBytes)
if err != nil {
return err
}
return cliCtx.PrintOutput(res)
}
// completeAndBroadcastETHTxCLI implements a utility function that facilitates
// sending a series of messages in a signed transaction given a TxBuilder and a
// QueryContext. It ensures that the account exists, has a proper number and
// sequence set. In addition, it builds and signs a transaction with the
// supplied messages. Finally, it broadcasts the signed transaction to a node.
// * Modified version from github.com/cosmos/cosmos-sdk/x/auth/client/utils/tx.go
func completeAndBroadcastETHTxCLI(txBldr authtypes.TxBuilder, cliCtx context.CLIContext, msgs []sdk.Msg) error {
txBldr, err := utils.PrepareTxBuilder(txBldr, cliCtx)
if err != nil {
return err
}
fromName := cliCtx.GetFromName()
if txBldr.SimulateAndExecute() || cliCtx.Simulate {
txBldr, err = utils.EnrichWithGas(txBldr, cliCtx, msgs)
if err != nil {
return err
}
gasEst := utils.GasEstimateResponse{GasEstimate: txBldr.Gas()}
_, _ = fmt.Fprintf(os.Stderr, "%s\n", gasEst.String())
}
if cliCtx.Simulate {
return nil
}
if !cliCtx.SkipConfirm {
stdSignMsg, err := txBldr.BuildSignMsg(msgs)
if err != nil {
return err
}
var json []byte
if viper.GetBool(flags.FlagIndentResponse) {
json, err = cliCtx.Codec.MarshalJSONIndent(stdSignMsg, "", " ")
if err != nil {
panic(err)
}
} else {
json = cliCtx.Codec.MustMarshalJSON(stdSignMsg)
}
_, _ = fmt.Fprintf(os.Stderr, "%s\n\n", json)
buf := bufio.NewReader(os.Stdin)
ok, err := input.GetConfirmation("confirm transaction before signing and broadcasting", buf)
if err != nil || !ok {
_, _ = fmt.Fprintf(os.Stderr, "%s\n", "cancelled transaction")
return err
}
}
// * This function is overriden to change the keybase reference here
passphrase, err := emintkeys.GetPassphrase(fromName)
if err != nil {
return err
}
// build and sign the transaction
// * needed to be modified also to change how the data is signed
txBytes, err := buildAndSign(txBldr, fromName, passphrase, msgs)
if err != nil {
return err
}
// broadcast to a Tendermint node
res, err := cliCtx.BroadcastTx(txBytes)
if err != nil {
return err
}
return cliCtx.PrintOutput(res)
}
// BuildAndSign builds a single message to be signed, and signs a transaction
// with the built message given a name, passphrase, and a set of messages.
// * overriden from github.com/cosmos/cosmos-sdk/x/auth/types/txbuilder.go
// * This is just modified to change the functionality in makeSignature, through sign
func buildAndSign(bldr authtypes.TxBuilder, name, passphrase string, msgs []sdk.Msg) ([]byte, error) {
msg, err := bldr.BuildSignMsg(msgs)
if err != nil {
return nil, err
}
return sign(bldr, name, passphrase, msg)
}
// Sign signs a transaction given a name, passphrase, and a single message to
// signed. An error is returned if signing fails.
func sign(bldr authtypes.TxBuilder, name, passphrase string, msg authtypes.StdSignMsg) ([]byte, error) {
sig, err := makeSignature(bldr.Keybase(), name, passphrase, msg)
if err != nil {
return nil, err
}
txEncoder := bldr.TxEncoder()
return txEncoder(authtypes.NewStdTx(msg.Msgs, msg.Fee, []authtypes.StdSignature{sig}, msg.Memo))
}
// MakeSignature builds a StdSignature given keybase, key name, passphrase, and a StdSignMsg.
func makeSignature(keybase crkeys.Keybase, name, passphrase string,
msg authtypes.StdSignMsg) (sig authtypes.StdSignature, err error) {
if keybase == nil {
// * This is overriden to allow ethermint keys, but not used because keybase is set
keybase, err = emintkeys.NewKeyBaseFromHomeFlag()
if err != nil {
return
}
}
// EthereumTxMsg always returns the data in the 0th index so it is safe to do this
var ethTx *evmtypes.EthereumTxMsg
ethTx, ok := msg.Msgs[0].(*evmtypes.EthereumTxMsg)
if !ok {
return sig, fmt.Errorf("Transaction message not an Ethereum Tx")
}
// TODO: Move this logic to after tx is rlp decoded in keybase Sign function
// parse the chainID from a string to a base-10 integer
chainID, ok := new(big.Int).SetString(msg.ChainID, 10)
if !ok {
return sig, emint.ErrInvalidChainID(fmt.Sprintf("invalid chainID: %s", msg.ChainID))
}
privKey, err := keybase.ExportPrivateKeyObject(name, passphrase)
if err != nil {
return
}
emintKey, ok := privKey.(emintcrypto.PrivKeySecp256k1)
if !ok {
panic(fmt.Sprintf("invalid private key type: %T", privKey))
}
ethTx.Sign(chainID, emintKey.ToECDSA())
// * This is needed to be overriden to get bytes to sign (RLPSignBytes) with the chainID
sigBytes, pubkey, err := keybase.Sign(name, passphrase, ethTx.RLPSignBytes(chainID).Bytes())
if err != nil {
return
}
return authtypes.StdSignature{
PubKey: pubkey,
Signature: sigBytes,
}, nil
}
// signEthTx populates the V, R, and S fields of an EthereumTxMsg using an ethermint key
func signEthTx(keybase crkeys.Keybase, name, passphrase string,
ethTx *evmtypes.EthereumTxMsg, chainID string) (_ *evmtypes.EthereumTxMsg, err error) {
if keybase == nil {
keybase, err = emintkeys.NewKeyBaseFromHomeFlag()
if err != nil {
return
}
}
// parse the chainID from a string to a base-10 integer
intChainID, ok := new(big.Int).SetString(chainID, 10)
if !ok {
return ethTx, emint.ErrInvalidChainID(fmt.Sprintf("invalid chainID: %s", chainID))
}
privKey, err := keybase.ExportPrivateKeyObject(name, passphrase)
if err != nil {
return
}
// Key must be a ethermint key to be able to be converted into an ECDSA private key to sign
emintKey, ok := privKey.(emintcrypto.PrivKeySecp256k1)
if !ok {
panic(fmt.Sprintf("invalid private key type: %T", privKey))
}
ethTx.Sign(intChainID, emintKey.ToECDSA())
return ethTx, err
}
// * This context is needed because the previous GetFromFields function would initialize a
// * default keybase to lookup the address or name. The new one overrides the keybase with the
// * ethereum compatible one
// NewCLIContextWithFrom returns a new initialized CLIContext with parameters from the
// command line using Viper. It takes a key name or address and populates the FromName and
// FromAddress field accordingly.
func NewETHCLIContext() context.CLIContext {
var nodeURI string
var rpc rpcclient.Client
from := viper.GetString(flags.FlagFrom)
genOnly := viper.GetBool(flags.FlagGenerateOnly)
// * This function is needed only to override this call to access correct keybase
fromAddress, fromName, err := getFromFields(from, genOnly)
if err != nil {
fmt.Printf("failed to get from fields: %v", err)
os.Exit(1)
}
if !genOnly {
nodeURI = viper.GetString(flags.FlagNode)
if nodeURI != "" {
rpc = rpcclient.NewHTTP(nodeURI, "/websocket")
}
}
return context.CLIContext{
Client: rpc,
Output: os.Stdout,
NodeURI: nodeURI,
From: viper.GetString(flags.FlagFrom),
OutputFormat: viper.GetString(cli.OutputFlag),
Height: viper.GetInt64(flags.FlagHeight),
TrustNode: viper.GetBool(flags.FlagTrustNode),
UseLedger: viper.GetBool(flags.FlagUseLedger),
BroadcastMode: viper.GetString(flags.FlagBroadcastMode),
// Verifier: verifier,
Simulate: viper.GetBool(flags.FlagDryRun),
GenerateOnly: genOnly,
FromAddress: fromAddress,
FromName: fromName,
Indent: viper.GetBool(flags.FlagIndentResponse),
SkipConfirm: viper.GetBool(flags.FlagSkipConfirmation),
}
}
// GetFromFields returns a from account address and Keybase name given either
// an address or key name. If genOnly is true, only a valid Bech32 cosmos
// address is returned.
func getFromFields(from string, genOnly bool) (sdk.AccAddress, string, error) {
if from == "" {
return nil, "", nil
}
if genOnly {
addr, err := sdk.AccAddressFromBech32(from)
if err != nil {
return nil, "", errors.Wrap(err, "must provide a valid Bech32 address for generate-only")
}
return addr, "", nil
}
// * This is the line that needed to be overriden, change could be to pass in optional keybase?
keybase, err := emintkeys.NewKeyBaseFromHomeFlag()
if err != nil {
return nil, "", err
}
var info crkeys.Info
if addr, err := sdk.AccAddressFromBech32(from); err == nil {
info, err = keybase.GetByAddress(addr)
if err != nil {
return nil, "", err
}
} else {
info, err = keybase.Get(from)
if err != nil {
return nil, "", err
}
}
return info.GetAddress(), info.GetName(), nil
}
+1 -1
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@@ -55,7 +55,7 @@ func (AppModuleBasic) GetQueryCmd(cdc *codec.Codec) *cobra.Command {
// Get the root tx command of this module
func (AppModuleBasic) GetTxCmd(cdc *codec.Codec) *cobra.Command {
return nil // cli.GetTxCmd(StoreKey, cdc)
return cli.GetTxCmd(types.ModuleName, cdc)
}
type AppModule struct {
+3 -3
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@@ -28,7 +28,7 @@ var big8 = big.NewInt(8)
// message type and route constants
const (
TypeEthereumTxMsg = "ethereum_tx"
RouteEthereumTxMsg = "evm"
RouteEthereumTxMsg = RouterKey
)
// EthereumTxMsg encapsulates an Ethereum transaction as an SDK message.
@@ -128,11 +128,11 @@ func (msg EthereumTxMsg) Type() string { return TypeEthereumTxMsg }
// checks of a Transaction. If returns an sdk.Error if validation fails.
func (msg EthereumTxMsg) ValidateBasic() sdk.Error {
if msg.Data.Price.Sign() != 1 {
return types.ErrInvalidValue("price must be positive")
return types.ErrInvalidValue(fmt.Sprintf("Price must be positive: %x", msg.Data.Price))
}
if msg.Data.Amount.Sign() != 1 {
return types.ErrInvalidValue("amount must be positive")
return types.ErrInvalidValue(fmt.Sprintf("amount must be positive: %x", msg.Data.Amount))
}
return nil
+153
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@@ -0,0 +1,153 @@
package types
import (
"math/big"
"github.com/cosmos/cosmos-sdk/codec"
ethcmn "github.com/ethereum/go-ethereum/common"
)
var cdc = codec.New()
func init() {
RegisterAmino(cdc)
}
// RegisterAmino registers all crypto related types in the given (amino) codec.
func RegisterAmino(cdc *codec.Codec) {
cdc.RegisterConcrete(EncodableTxData{}, "ethermint/EncodedMessage", nil)
}
// TxData implements the Ethereum transaction data structure. It is used
// solely as intended in Ethereum abiding by the protocol.
type EncodableTxData struct {
AccountNonce uint64 `json:"nonce"`
Price string `json:"gasPrice"`
GasLimit uint64 `json:"gas"`
Recipient *ethcmn.Address `json:"to" rlp:"nil"` // nil means contract creation
Amount string `json:"value"`
Payload []byte `json:"input"`
// signature values
V string `json:"v"`
R string `json:"r"`
S string `json:"s"`
// hash is only used when marshaling to JSON
Hash *ethcmn.Hash `json:"hash" rlp:"-"`
}
func marshalAmino(td EncodableTxData) (string, error) {
bz, err := cdc.MarshalBinaryBare(td)
return string(bz), err
}
func unmarshalAmino(td *EncodableTxData, text string) (err error) {
return cdc.UnmarshalBinaryBare([]byte(text), td)
}
func marshalBigInt(i *big.Int) string {
bz, err := i.MarshalText()
if err != nil {
panic(err)
}
return string(bz)
}
func unmarshalBigInt(s string) (*big.Int, error) {
ret := new(big.Int)
err := ret.UnmarshalText([]byte(s))
return ret, err
}
// MarshalAmino defines custom encoding scheme for TxData
func (td TxData) MarshalAmino() (string, error) {
e := EncodableTxData{
AccountNonce: td.AccountNonce,
Price: marshalBigInt(td.Price),
GasLimit: td.GasLimit,
Recipient: td.Recipient,
Amount: marshalBigInt(td.Amount),
Payload: td.Payload,
V: marshalBigInt(td.V),
R: marshalBigInt(td.R),
S: marshalBigInt(td.S),
Hash: td.Hash,
}
return marshalAmino(e)
}
// UnmarshalAmino defines custom decoding scheme for TxData
func (td *TxData) UnmarshalAmino(text string) (err error) {
e := new(EncodableTxData)
err = unmarshalAmino(e, text)
if err != nil {
return
}
td.AccountNonce = e.AccountNonce
td.GasLimit = e.GasLimit
td.Recipient = e.Recipient
td.Payload = e.Payload
td.Hash = e.Hash
price, err := unmarshalBigInt(e.Price)
if err != nil {
return
}
if td.Price != nil {
td.Price.Set(price)
} else {
td.Price = price
}
amt, err := unmarshalBigInt(e.Amount)
if err != nil {
return
}
if td.Amount != nil {
td.Amount.Set(amt)
} else {
td.Amount = amt
}
v, err := unmarshalBigInt(e.V)
if err != nil {
return
}
if td.V != nil {
td.V.Set(v)
} else {
td.V = v
}
r, err := unmarshalBigInt(e.R)
if err != nil {
return
}
if td.R != nil {
td.R.Set(r)
} else {
td.R = r
}
s, err := unmarshalBigInt(e.S)
if err != nil {
return
}
if td.S != nil {
td.S.Set(s)
} else {
td.S = s
}
return
}
// TODO: Implement JSON marshaling/ unmarshaling for this type
// TODO: Implement YAML marshaling/ unmarshaling for this type
+41 -1
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@@ -122,7 +122,11 @@ func TestMsgEthereumTxSig(t *testing.T) {
func TestMsgEthereumTxAmino(t *testing.T) {
addr := GenerateEthAddress()
msg := NewEthereumTxMsg(0, addr, nil, 100000, nil, []byte("test"))
msg := NewEthereumTxMsg(5, addr, big.NewInt(1), 100000, big.NewInt(3), []byte("test"))
msg.Data.V = big.NewInt(1)
msg.Data.R = big.NewInt(2)
msg.Data.S = big.NewInt(3)
raw, err := ModuleCdc.MarshalBinaryBare(msg)
require.NoError(t, err)
@@ -133,3 +137,39 @@ func TestMsgEthereumTxAmino(t *testing.T) {
require.NoError(t, err)
require.Equal(t, msg.Data, msg2.Data)
}
func TestMarshalAndUnmarshalInt(t *testing.T) {
i := big.NewInt(3)
m := marshalBigInt(i)
i2, err := unmarshalBigInt(m)
require.NoError(t, err)
require.Equal(t, i, i2)
}
func TestMarshalAndUnmarshalData(t *testing.T) {
addr := GenerateEthAddress()
hash := ethcmn.BigToHash(big.NewInt(2))
e := EncodableTxData{
AccountNonce: 2,
Price: marshalBigInt(big.NewInt(3)),
GasLimit: 1,
Recipient: &addr,
Amount: marshalBigInt(big.NewInt(4)),
Payload: []byte("test"),
V: marshalBigInt(big.NewInt(5)),
R: marshalBigInt(big.NewInt(6)),
S: marshalBigInt(big.NewInt(7)),
Hash: &hash,
}
str, err := marshalAmino(e)
require.NoError(t, err)
e2 := new(EncodableTxData)
err = unmarshalAmino(e2, str)
require.NoError(t, err)
require.Equal(t, e, *e2)
}