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Diffstat (limited to 'accounts/usbwallet/trezor.go')
| -rw-r--r-- | accounts/usbwallet/trezor.go | 365 |
1 files changed, 365 insertions, 0 deletions
diff --git a/accounts/usbwallet/trezor.go b/accounts/usbwallet/trezor.go new file mode 100644 index 0000000..833c7a9 --- /dev/null +++ b/accounts/usbwallet/trezor.go @@ -0,0 +1,365 @@ +// Copyright 2017 The go-ethereum Authors +// This file is part of the go-ethereum library. +// +// The go-ethereum library is free software: you can redistribute it and/or modify +// it under the terms of the GNU Lesser General Public License as published by +// the Free Software Foundation, either version 3 of the License, or +// (at your option) any later version. +// +// The go-ethereum library is distributed in the hope that it will be useful, +// but WITHOUT ANY WARRANTY; without even the implied warranty of +// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +// GNU Lesser General Public License for more details. +// +// You should have received a copy of the GNU Lesser General Public License +// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>. + +// This file contains the implementation for interacting with the Trezor hardware +// wallets. The wire protocol spec can be found on the SatoshiLabs website: +// https://doc.satoshilabs.com/trezor-tech/api-protobuf.html + +package usbwallet + +import ( + "encoding/binary" + "errors" + "fmt" + "io" + "math/big" + + "github.com/ava-labs/coreth/accounts" + "github.com/ava-labs/coreth/accounts/usbwallet/trezor" + "github.com/ava-labs/coreth/core/types" + "github.com/ava-labs/go-ethereum/common" + "github.com/ava-labs/go-ethereum/common/hexutil" + "github.com/ava-labs/go-ethereum/log" + "github.com/golang/protobuf/proto" +) + +// ErrTrezorPINNeeded is returned if opening the trezor requires a PIN code. In +// this case, the calling application should display a pinpad and send back the +// encoded passphrase. +var ErrTrezorPINNeeded = errors.New("trezor: pin needed") + +// ErrTrezorPassphraseNeeded is returned if opening the trezor requires a passphrase +var ErrTrezorPassphraseNeeded = errors.New("trezor: passphrase needed") + +// errTrezorReplyInvalidHeader is the error message returned by a Trezor data exchange +// if the device replies with a mismatching header. This usually means the device +// is in browser mode. +var errTrezorReplyInvalidHeader = errors.New("trezor: invalid reply header") + +// trezorDriver implements the communication with a Trezor hardware wallet. +type trezorDriver struct { + device io.ReadWriter // USB device connection to communicate through + version [3]uint32 // Current version of the Trezor firmware + label string // Current textual label of the Trezor device + pinwait bool // Flags whether the device is waiting for PIN entry + passphrasewait bool // Flags whether the device is waiting for passphrase entry + failure error // Any failure that would make the device unusable + log log.Logger // Contextual logger to tag the trezor with its id +} + +// newTrezorDriver creates a new instance of a Trezor USB protocol driver. +func newTrezorDriver(logger log.Logger) driver { + return &trezorDriver{ + log: logger, + } +} + +// Status implements accounts.Wallet, always whether the Trezor is opened, closed +// or whether the Ethereum app was not started on it. +func (w *trezorDriver) Status() (string, error) { + if w.failure != nil { + return fmt.Sprintf("Failed: %v", w.failure), w.failure + } + if w.device == nil { + return "Closed", w.failure + } + if w.pinwait { + return fmt.Sprintf("Trezor v%d.%d.%d '%s' waiting for PIN", w.version[0], w.version[1], w.version[2], w.label), w.failure + } + return fmt.Sprintf("Trezor v%d.%d.%d '%s' online", w.version[0], w.version[1], w.version[2], w.label), w.failure +} + +// Open implements usbwallet.driver, attempting to initialize the connection to +// the Trezor hardware wallet. Initializing the Trezor is a two or three phase operation: +// * The first phase is to initialize the connection and read the wallet's +// features. This phase is invoked if the provided passphrase is empty. The +// device will display the pinpad as a result and will return an appropriate +// error to notify the user that a second open phase is needed. +// * The second phase is to unlock access to the Trezor, which is done by the +// user actually providing a passphrase mapping a keyboard keypad to the pin +// number of the user (shuffled according to the pinpad displayed). +// * If needed the device will ask for passphrase which will require calling +// open again with the actual passphrase (3rd phase) +func (w *trezorDriver) Open(device io.ReadWriter, passphrase string) error { + w.device, w.failure = device, nil + + // If phase 1 is requested, init the connection and wait for user callback + if passphrase == "" && !w.passphrasewait { + // If we're already waiting for a PIN entry, insta-return + if w.pinwait { + return ErrTrezorPINNeeded + } + // Initialize a connection to the device + features := new(trezor.Features) + if _, err := w.trezorExchange(&trezor.Initialize{}, features); err != nil { + return err + } + w.version = [3]uint32{features.GetMajorVersion(), features.GetMinorVersion(), features.GetPatchVersion()} + w.label = features.GetLabel() + + // Do a manual ping, forcing the device to ask for its PIN and Passphrase + askPin := true + askPassphrase := true + res, err := w.trezorExchange(&trezor.Ping{PinProtection: &askPin, PassphraseProtection: &askPassphrase}, new(trezor.PinMatrixRequest), new(trezor.PassphraseRequest), new(trezor.Success)) + if err != nil { + return err + } + // Only return the PIN request if the device wasn't unlocked until now + switch res { + case 0: + w.pinwait = true + return ErrTrezorPINNeeded + case 1: + w.pinwait = false + w.passphrasewait = true + return ErrTrezorPassphraseNeeded + case 2: + return nil // responded with trezor.Success + } + } + // Phase 2 requested with actual PIN entry + if w.pinwait { + w.pinwait = false + res, err := w.trezorExchange(&trezor.PinMatrixAck{Pin: &passphrase}, new(trezor.Success), new(trezor.PassphraseRequest)) + if err != nil { + w.failure = err + return err + } + if res == 1 { + w.passphrasewait = true + return ErrTrezorPassphraseNeeded + } + } else if w.passphrasewait { + w.passphrasewait = false + if _, err := w.trezorExchange(&trezor.PassphraseAck{Passphrase: &passphrase}, new(trezor.Success)); err != nil { + w.failure = err + return err + } + } + + return nil +} + +// Close implements usbwallet.driver, cleaning up and metadata maintained within +// the Trezor driver. +func (w *trezorDriver) Close() error { + w.version, w.label, w.pinwait = [3]uint32{}, "", false + return nil +} + +// Heartbeat implements usbwallet.driver, performing a sanity check against the +// Trezor to see if it's still online. +func (w *trezorDriver) Heartbeat() error { + if _, err := w.trezorExchange(&trezor.Ping{}, new(trezor.Success)); err != nil { + w.failure = err + return err + } + return nil +} + +// Derive implements usbwallet.driver, sending a derivation request to the Trezor +// and returning the Ethereum address located on that derivation path. +func (w *trezorDriver) Derive(path accounts.DerivationPath) (common.Address, error) { + return w.trezorDerive(path) +} + +// SignTx implements usbwallet.driver, sending the transaction to the Trezor and +// waiting for the user to confirm or deny the transaction. +func (w *trezorDriver) SignTx(path accounts.DerivationPath, tx *types.Transaction, chainID *big.Int) (common.Address, *types.Transaction, error) { + if w.device == nil { + return common.Address{}, nil, accounts.ErrWalletClosed + } + return w.trezorSign(path, tx, chainID) +} + +// trezorDerive sends a derivation request to the Trezor device and returns the +// Ethereum address located on that path. +func (w *trezorDriver) trezorDerive(derivationPath []uint32) (common.Address, error) { + address := new(trezor.EthereumAddress) + if _, err := w.trezorExchange(&trezor.EthereumGetAddress{AddressN: derivationPath}, address); err != nil { + return common.Address{}, err + } + if addr := address.GetAddressBin(); len(addr) > 0 { // Older firmwares use binary fomats + return common.BytesToAddress(addr), nil + } + if addr := address.GetAddressHex(); len(addr) > 0 { // Newer firmwares use hexadecimal fomats + return common.HexToAddress(addr), nil + } + return common.Address{}, errors.New("missing derived address") +} + +// trezorSign sends the transaction to the Trezor wallet, and waits for the user +// to confirm or deny the transaction. +func (w *trezorDriver) trezorSign(derivationPath []uint32, tx *types.Transaction, chainID *big.Int) (common.Address, *types.Transaction, error) { + // Create the transaction initiation message + data := tx.Data() + length := uint32(len(data)) + + request := &trezor.EthereumSignTx{ + AddressN: derivationPath, + Nonce: new(big.Int).SetUint64(tx.Nonce()).Bytes(), + GasPrice: tx.GasPrice().Bytes(), + GasLimit: new(big.Int).SetUint64(tx.Gas()).Bytes(), + Value: tx.Value().Bytes(), + DataLength: &length, + } + if to := tx.To(); to != nil { + // Non contract deploy, set recipient explicitly + hex := to.Hex() + request.ToHex = &hex // Newer firmwares (old will ignore) + request.ToBin = (*to)[:] // Older firmwares (new will ignore) + } + if length > 1024 { // Send the data chunked if that was requested + request.DataInitialChunk, data = data[:1024], data[1024:] + } else { + request.DataInitialChunk, data = data, nil + } + if chainID != nil { // EIP-155 transaction, set chain ID explicitly (only 32 bit is supported!?) + id := uint32(chainID.Int64()) + request.ChainId = &id + } + // Send the initiation message and stream content until a signature is returned + response := new(trezor.EthereumTxRequest) + if _, err := w.trezorExchange(request, response); err != nil { + return common.Address{}, nil, err + } + for response.DataLength != nil && int(*response.DataLength) <= len(data) { + chunk := data[:*response.DataLength] + data = data[*response.DataLength:] + + if _, err := w.trezorExchange(&trezor.EthereumTxAck{DataChunk: chunk}, response); err != nil { + return common.Address{}, nil, err + } + } + // Extract the Ethereum signature and do a sanity validation + if len(response.GetSignatureR()) == 0 || len(response.GetSignatureS()) == 0 || response.GetSignatureV() == 0 { + return common.Address{}, nil, errors.New("reply lacks signature") + } + signature := append(append(response.GetSignatureR(), response.GetSignatureS()...), byte(response.GetSignatureV())) + + // Create the correct signer and signature transform based on the chain ID + var signer types.Signer + if chainID == nil { + signer = new(types.HomesteadSigner) + } else { + signer = types.NewEIP155Signer(chainID) + signature[64] -= byte(chainID.Uint64()*2 + 35) + } + // Inject the final signature into the transaction and sanity check the sender + signed, err := tx.WithSignature(signer, signature) + if err != nil { + return common.Address{}, nil, err + } + sender, err := types.Sender(signer, signed) + if err != nil { + return common.Address{}, nil, err + } + return sender, signed, nil +} + +// trezorExchange performs a data exchange with the Trezor wallet, sending it a +// message and retrieving the response. If multiple responses are possible, the +// method will also return the index of the destination object used. +func (w *trezorDriver) trezorExchange(req proto.Message, results ...proto.Message) (int, error) { + // Construct the original message payload to chunk up + data, err := proto.Marshal(req) + if err != nil { + return 0, err + } + payload := make([]byte, 8+len(data)) + copy(payload, []byte{0x23, 0x23}) + binary.BigEndian.PutUint16(payload[2:], trezor.Type(req)) + binary.BigEndian.PutUint32(payload[4:], uint32(len(data))) + copy(payload[8:], data) + + // Stream all the chunks to the device + chunk := make([]byte, 64) + chunk[0] = 0x3f // Report ID magic number + + for len(payload) > 0 { + // Construct the new message to stream, padding with zeroes if needed + if len(payload) > 63 { + copy(chunk[1:], payload[:63]) + payload = payload[63:] + } else { + copy(chunk[1:], payload) + copy(chunk[1+len(payload):], make([]byte, 63-len(payload))) + payload = nil + } + // Send over to the device + w.log.Trace("Data chunk sent to the Trezor", "chunk", hexutil.Bytes(chunk)) + if _, err := w.device.Write(chunk); err != nil { + return 0, err + } + } + // Stream the reply back from the wallet in 64 byte chunks + var ( + kind uint16 + reply []byte + ) + for { + // Read the next chunk from the Trezor wallet + if _, err := io.ReadFull(w.device, chunk); err != nil { + return 0, err + } + w.log.Trace("Data chunk received from the Trezor", "chunk", hexutil.Bytes(chunk)) + + // Make sure the transport header matches + if chunk[0] != 0x3f || (len(reply) == 0 && (chunk[1] != 0x23 || chunk[2] != 0x23)) { + return 0, errTrezorReplyInvalidHeader + } + // If it's the first chunk, retrieve the reply message type and total message length + var payload []byte + + if len(reply) == 0 { + kind = binary.BigEndian.Uint16(chunk[3:5]) + reply = make([]byte, 0, int(binary.BigEndian.Uint32(chunk[5:9]))) + payload = chunk[9:] + } else { + payload = chunk[1:] + } + // Append to the reply and stop when filled up + if left := cap(reply) - len(reply); left > len(payload) { + reply = append(reply, payload...) + } else { + reply = append(reply, payload[:left]...) + break + } + } + // Try to parse the reply into the requested reply message + if kind == uint16(trezor.MessageType_MessageType_Failure) { + // Trezor returned a failure, extract and return the message + failure := new(trezor.Failure) + if err := proto.Unmarshal(reply, failure); err != nil { + return 0, err + } + return 0, errors.New("trezor: " + failure.GetMessage()) + } + if kind == uint16(trezor.MessageType_MessageType_ButtonRequest) { + // Trezor is waiting for user confirmation, ack and wait for the next message + return w.trezorExchange(&trezor.ButtonAck{}, results...) + } + for i, res := range results { + if trezor.Type(res) == kind { + return i, proto.Unmarshal(reply, res) + } + } + expected := make([]string, len(results)) + for i, res := range results { + expected[i] = trezor.Name(trezor.Type(res)) + } + return 0, fmt.Errorf("trezor: expected reply types %s, got %s", expected, trezor.Name(kind)) +} |