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-rw-r--r--accounts/usbwallet/ledger_wallet.go670
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diff --git a/accounts/usbwallet/ledger_wallet.go b/accounts/usbwallet/ledger_wallet.go
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+// 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 Ledger hardware
+// wallets. The wire protocol spec can be found in the Ledger Blue GitHub repo:
+// https://raw.githubusercontent.com/LedgerHQ/blue-app-eth/master/doc/ethapp.asc
+
+// +build !ios
+
+package usbwallet
+
+import (
+ "encoding/binary"
+ "encoding/hex"
+ "errors"
+ "fmt"
+ "io"
+ "math/big"
+ "strconv"
+ "strings"
+ "sync"
+ "time"
+
+ "github.com/ethereum/go-ethereum/accounts"
+ "github.com/ethereum/go-ethereum/common"
+ "github.com/ethereum/go-ethereum/core/types"
+ "github.com/ethereum/go-ethereum/logger"
+ "github.com/ethereum/go-ethereum/logger/glog"
+ "github.com/ethereum/go-ethereum/rlp"
+ "github.com/karalabe/gousb/usb"
+)
+
+// ledgerDerivationPath is the base derivation parameters used by the wallet.
+var ledgerDerivationPath = []uint32{0x80000000 + 44, 0x80000000 + 60, 0x80000000 + 0, 0}
+
+// ledgerOpcode is an enumeration encoding the supported Ledger opcodes.
+type ledgerOpcode byte
+
+// ledgerParam1 is an enumeration encoding the supported Ledger parameters for
+// specific opcodes. The same parameter values may be reused between opcodes.
+type ledgerParam1 byte
+
+// ledgerParam2 is an enumeration encoding the supported Ledger parameters for
+// specific opcodes. The same parameter values may be reused between opcodes.
+type ledgerParam2 byte
+
+const (
+ ledgerOpRetrieveAddress ledgerOpcode = 0x02 // Returns the public key and Ethereum address for a given BIP 32 path
+ ledgerOpSignTransaction ledgerOpcode = 0x04 // Signs an Ethereum transaction after having the user validate the parameters
+ ledgerOpGetConfiguration ledgerOpcode = 0x06 // Returns specific wallet application configuration
+
+ ledgerP1DirectlyFetchAddress ledgerParam1 = 0x00 // Return address directly from the wallet
+ ledgerP1ConfirmFetchAddress ledgerParam1 = 0x01 // Require a user confirmation before returning the address
+ ledgerP1InitTransactionData ledgerParam1 = 0x00 // First transaction data block for signing
+ ledgerP1ContTransactionData ledgerParam1 = 0x80 // Subsequent transaction data block for signing
+ ledgerP2DiscardAddressChainCode ledgerParam2 = 0x00 // Do not return the chain code along with the address
+ ledgerP2ReturnAddressChainCode ledgerParam2 = 0x01 // Require a user confirmation before returning the address
+)
+
+// ledgerWallet represents a live USB Ledger hardware wallet.
+type ledgerWallet struct {
+ context *usb.Context // USB context to interface libusb through
+ hardwareID deviceID // USB identifiers to identify this device type
+ locationID uint16 // USB bus and address to identify this device instance
+ url string // Textual URL uniquely identifying this wallet
+
+ device *usb.Device // USB device advertising itself as a Ledger wallet
+ input usb.Endpoint // Input endpoint to send data to this device
+ output usb.Endpoint // Output endpoint to receive data from this device
+ failure error // Any failure that would make the device unusable
+
+ version [3]byte // Current version of the Ledger Ethereum app (zero if app is offline)
+ accounts []accounts.Account // List of derive accounts pinned on the Ledger
+ paths map[common.Address][]uint32 // Known derivation paths for signing operations
+
+ quit chan chan error
+ lock sync.RWMutex
+}
+
+// Type implements accounts.Wallet, returning the textual type of the wallet.
+func (w *ledgerWallet) Type() string {
+ return "ledger"
+}
+
+// URL implements accounts.Wallet, returning the URL of the Ledger device.
+func (w *ledgerWallet) URL() string {
+ return w.url
+}
+
+// Status implements accounts.Wallet, always whether the Ledger is opened, closed
+// or whether the Ethereum app was not started on it.
+func (w *ledgerWallet) Status() string {
+ w.lock.RLock()
+ defer w.lock.RUnlock()
+
+ if w.failure != nil {
+ return fmt.Sprintf("Failed: %v", w.failure)
+ }
+ if w.device == nil {
+ return "Closed"
+ }
+ if w.version == [3]byte{0, 0, 0} {
+ return "Ethereum app not started"
+ }
+ return fmt.Sprintf("Ethereum app v%d.%d.%d", w.version[0], w.version[1], w.version[2])
+}
+
+// Open implements accounts.Wallet, attempting to open a USB connection to the
+// Ledger hardware wallet. The Ledger does not require a user passphrase so that
+// is silently discarded.
+func (w *ledgerWallet) Open(passphrase string) error {
+ w.lock.Lock()
+ defer w.lock.Unlock()
+
+ // If the wallet was already opened, don't try to open again
+ if w.device != nil {
+ return accounts.ErrWalletAlreadyOpen
+ }
+ // Otherwise iterate over all USB devices and find this again (no way to directly do this)
+ // Iterate over all attached devices and fetch those seemingly Ledger
+ devices, err := w.context.ListDevices(func(desc *usb.Descriptor) bool {
+ // Only open this single specific device
+ return desc.Vendor == w.hardwareID.Vendor && desc.Product == w.hardwareID.Product &&
+ uint16(desc.Bus)<<8+uint16(desc.Address) == w.locationID
+ })
+ if err != nil {
+ return err
+ }
+ // Device opened, attach to the input and output endpoints
+ device := devices[0]
+
+ var invalid string
+ switch {
+ case len(device.Descriptor.Configs) == 0:
+ invalid = "no endpoint config available"
+ case len(device.Descriptor.Configs[0].Interfaces) == 0:
+ invalid = "no endpoint interface available"
+ case len(device.Descriptor.Configs[0].Interfaces[0].Setups) == 0:
+ invalid = "no endpoint setup available"
+ case len(device.Descriptor.Configs[0].Interfaces[0].Setups[0].Endpoints) < 2:
+ invalid = "not enough IO endpoints available"
+ }
+ if invalid != "" {
+ device.Close()
+ return fmt.Errorf("ledger wallet [%s] invalid: %s", w.url, invalid)
+ }
+ // Open the input and output endpoints to the device
+ input, err := device.OpenEndpoint(
+ device.Descriptor.Configs[0].Config,
+ device.Descriptor.Configs[0].Interfaces[0].Number,
+ device.Descriptor.Configs[0].Interfaces[0].Setups[0].Number,
+ device.Descriptor.Configs[0].Interfaces[0].Setups[0].Endpoints[1].Address,
+ )
+ if err != nil {
+ device.Close()
+ return fmt.Errorf("ledger wallet [%s] input open failed: %v", w.url, err)
+ }
+ output, err := device.OpenEndpoint(
+ device.Descriptor.Configs[0].Config,
+ device.Descriptor.Configs[0].Interfaces[0].Number,
+ device.Descriptor.Configs[0].Interfaces[0].Setups[0].Number,
+ device.Descriptor.Configs[0].Interfaces[0].Setups[0].Endpoints[0].Address,
+ )
+ if err != nil {
+ device.Close()
+ return fmt.Errorf("ledger wallet [%s] output open failed: %v", w.url, err)
+ }
+ // Wallet seems to be successfully opened, guess if the Ethereum app is running
+ w.device, w.input, w.output = device, input, output
+
+ w.paths = make(map[common.Address][]uint32)
+ w.quit = make(chan chan error)
+ defer func() {
+ go w.heartbeat()
+ }()
+
+ if _, err := w.deriveAddress(ledgerDerivationPath); err != nil {
+ // Ethereum app is not running, nothing more to do, return
+ return nil
+ }
+ // Try to resolve the Ethereum app's version, will fail prior to v1.0.2
+ if w.resolveVersion() != nil {
+ w.version = [3]byte{1, 0, 0} // Assume worst case, can't verify if v1.0.0 or v1.0.1
+ }
+ return nil
+}
+
+// heartbeat is a health check loop for the Ledger wallets to periodically verify
+// whether they are still present or if they malfunctioned. It is needed because:
+// - libusb on Windows doesn't support hotplug, so we can't detect USB unplugs
+// - communication timeout on the Ledger requires a device power cycle to fix
+func (w *ledgerWallet) heartbeat() {
+ // Execute heartbeat checks until termination or error
+ var (
+ errc chan error
+ fail error
+ )
+ for errc == nil && fail == nil {
+ // Wait until termination is requested or the heartbeat cycle arrives
+ select {
+ case errc = <-w.quit:
+ // Termination requested
+ continue
+ case <-time.After(time.Second):
+ // Heartbeat time
+ }
+ // Execute a tiny data exchange to see responsiveness
+ w.lock.Lock()
+ if err := w.resolveVersion(); err == usb.ERROR_IO || err == usb.ERROR_NO_DEVICE {
+ w.failure = err
+ fail = err
+ }
+ w.lock.Unlock()
+ }
+ // In case of error, wait for termination
+ if fail != nil {
+ errc = <-w.quit
+ }
+ errc <- fail
+}
+
+// Close implements accounts.Wallet, closing the USB connection to the Ledger.
+func (w *ledgerWallet) Close() error {
+ // Terminate the health checks
+ errc := make(chan error)
+ w.quit <- errc
+ herr := <-errc // Save for later, we *must* close the USB
+
+ // Terminate the device connection
+ w.lock.Lock()
+ defer w.lock.Unlock()
+
+ if err := w.device.Close(); err != nil {
+ return err
+ }
+ w.device, w.input, w.output, w.paths, w.quit = nil, nil, nil, nil, nil
+
+ return herr // If all went well, return any health-check errors
+}
+
+// Accounts implements accounts.Wallet, returning the list of accounts pinned to
+// the Ledger hardware wallet.
+func (w *ledgerWallet) Accounts() []accounts.Account {
+ w.lock.RLock()
+ defer w.lock.RUnlock()
+
+ cpy := make([]accounts.Account, len(w.accounts))
+ copy(cpy, w.accounts)
+ return cpy
+}
+
+// Contains implements accounts.Wallet, returning whether a particular account is
+// or is not pinned into this Ledger instance. Although we could attempt to resolve
+// unpinned accounts, that would be an non-negligible hardware operation.
+func (w *ledgerWallet) Contains(account accounts.Account) bool {
+ w.lock.RLock()
+ defer w.lock.RUnlock()
+
+ _, exists := w.paths[account.Address]
+ return exists
+}
+
+// Derive implements accounts.Wallet, deriving a new account at the specific
+// derivation path. If pin is set to true, the account will be added to the list
+// of tracked accounts.
+func (w *ledgerWallet) Derive(path string, pin bool) (accounts.Account, error) {
+ w.lock.Lock()
+ defer w.lock.Unlock()
+
+ // If the wallet is closed, or the Ethereum app doesn't run, abort
+ if w.device == nil || w.version == [3]byte{0, 0, 0} {
+ return accounts.Account{}, accounts.ErrWalletClosed
+ }
+ // All seems fine, convert the user derivation path to Ledger representation
+ path = strings.TrimPrefix(path, "/")
+
+ parts := strings.Split(path, "/")
+ lpath := make([]uint32, len(parts))
+ for i, part := range parts {
+ // Handle hardened paths
+ if strings.HasSuffix(part, "'") {
+ lpath[i] = 0x80000000
+ part = strings.TrimSuffix(part, "'")
+ }
+ // Handle the non hardened component
+ val, err := strconv.Atoi(part)
+ if err != nil {
+ return accounts.Account{}, fmt.Errorf("path element %d: %v", i, err)
+ }
+ lpath[i] += uint32(val)
+ }
+ // Try to derive the actual account and update it's URL if succeeful
+ address, err := w.deriveAddress(lpath)
+ if err != nil {
+ return accounts.Account{}, err
+ }
+ account := accounts.Account{
+ Address: address,
+ URL: fmt.Sprintf("%s/%s", w.url, path),
+ }
+ // If pinning was requested, track the account
+ if pin {
+ if _, ok := w.paths[address]; !ok {
+ w.accounts = append(w.accounts, account)
+ w.paths[address] = lpath
+ }
+ }
+ return account, nil
+}
+
+// SignHash implements accounts.Wallet, however signing arbitrary data is not
+// supported for Ledger wallets, so this method will always return an error.
+func (w *ledgerWallet) SignHash(acc accounts.Account, hash []byte) ([]byte, error) {
+ return nil, accounts.ErrNotSupported
+}
+
+// SignTx implements accounts.Wallet. It sends the transaction over to the Ledger
+// wallet to request a confirmation from the user. It returns either the signed
+// transaction or a failure if the user denied the transaction.
+//
+// Note, if the version of the Ethereum application running on the Ledger wallet is
+// too old to sign EIP-155 transactions, but such is requested nonetheless, an error
+// will be returned opposed to silently signing in Homestead mode.
+func (w *ledgerWallet) SignTx(account accounts.Account, tx *types.Transaction, chainID *big.Int) (*types.Transaction, error) {
+ w.lock.Lock()
+ defer w.lock.Unlock()
+
+ // Make sure the requested account is contained within
+ path, ok := w.paths[account.Address]
+ if !ok {
+ return nil, accounts.ErrUnknownAccount
+ }
+ // Ensure the wallet is capable of signing the given transaction
+ if chainID != nil && w.version[0] <= 1 && w.version[1] <= 0 && w.version[2] <= 2 {
+ return nil, fmt.Errorf("Ledger v%d.%d.%d doesn't support signing this transaction, please update to v1.0.3 at least",
+ w.version[0], w.version[1], w.version[2])
+ }
+ return w.sign(path, account.Address, tx, chainID)
+}
+
+// SignHashWithPassphrase implements accounts.Wallet, however signing arbitrary
+// data is not supported for Ledger wallets, so this method will always return
+// an error.
+func (w *ledgerWallet) SignHashWithPassphrase(account accounts.Account, passphrase string, hash []byte) ([]byte, error) {
+ return nil, accounts.ErrNotSupported
+}
+
+// SignTxWithPassphrase implements accounts.Wallet, attempting to sign the given
+// transaction with the given account using passphrase as extra authentication.
+// Since the Ledger does not support extra passphrases, it is silently ignored.
+func (w *ledgerWallet) SignTxWithPassphrase(account accounts.Account, passphrase string, tx *types.Transaction, chainID *big.Int) (*types.Transaction, error) {
+ return w.SignTx(account, tx, chainID)
+}
+
+// resolveVersion retrieves the current version of the Ethereum wallet app running
+// on the Ledger wallet and caches it for future reference.
+//
+// The version retrieval protocol is defined as follows:
+//
+// CLA | INS | P1 | P2 | Lc | Le
+// ----+-----+----+----+----+---
+// E0 | 06 | 00 | 00 | 00 | 04
+//
+// With no input data, and the output data being:
+//
+// Description | Length
+// ---------------------------------------------------+--------
+// Flags 01: arbitrary data signature enabled by user | 1 byte
+// Application major version | 1 byte
+// Application minor version | 1 byte
+// Application patch version | 1 byte
+func (wallet *ledgerWallet) resolveVersion() error {
+ // Send the request and wait for the response
+ reply, err := wallet.exchange(ledgerOpGetConfiguration, 0, 0, nil)
+ if err != nil {
+ return err
+ }
+ if len(reply) != 4 {
+ return errors.New("reply not of correct size")
+ }
+ // Cache the version for future reference
+ copy(wallet.version[:], reply[1:])
+ return nil
+}
+
+// deriveAddress retrieves the currently active Ethereum address from a Ledger
+// wallet at the specified derivation path.
+//
+// The address derivation protocol is defined as follows:
+//
+// CLA | INS | P1 | P2 | Lc | Le
+// ----+-----+----+----+-----+---
+// E0 | 02 | 00 return address
+// 01 display address and confirm before returning
+// | 00: do not return the chain code
+// | 01: return the chain code
+// | var | 00
+//
+// Where the input data is:
+//
+// Description | Length
+// -------------------------------------------------+--------
+// Number of BIP 32 derivations to perform (max 10) | 1 byte
+// First derivation index (big endian) | 4 bytes
+// ... | 4 bytes
+// Last derivation index (big endian) | 4 bytes
+//
+// And the output data is:
+//
+// Description | Length
+// ------------------------+-------------------
+// Public Key length | 1 byte
+// Uncompressed Public Key | arbitrary
+// Ethereum address length | 1 byte
+// Ethereum address | 40 bytes hex ascii
+// Chain code if requested | 32 bytes
+func (w *ledgerWallet) deriveAddress(derivationPath []uint32) (common.Address, error) {
+ // Flatten the derivation path into the Ledger request
+ path := make([]byte, 1+4*len(derivationPath))
+ path[0] = byte(len(derivationPath))
+ for i, component := range derivationPath {
+ binary.BigEndian.PutUint32(path[1+4*i:], component)
+ }
+ // Send the request and wait for the response
+ reply, err := w.exchange(ledgerOpRetrieveAddress, ledgerP1DirectlyFetchAddress, ledgerP2DiscardAddressChainCode, path)
+ if err != nil {
+ return common.Address{}, err
+ }
+ // Discard the public key, we don't need that for now
+ if len(reply) < 1 || len(reply) < 1+int(reply[0]) {
+ return common.Address{}, errors.New("reply lacks public key entry")
+ }
+ reply = reply[1+int(reply[0]):]
+
+ // Extract the Ethereum hex address string
+ if len(reply) < 1 || len(reply) < 1+int(reply[0]) {
+ return common.Address{}, errors.New("reply lacks address entry")
+ }
+ hexstr := reply[1 : 1+int(reply[0])]
+
+ // Decode the hex sting into an Ethereum address and return
+ var address common.Address
+ hex.Decode(address[:], hexstr)
+ return address, nil
+}
+
+// sign sends the transaction to the Ledger wallet, and waits for the user to
+// confirm or deny the transaction.
+//
+// The transaction signing protocol is defined as follows:
+//
+// CLA | INS | P1 | P2 | Lc | Le
+// ----+-----+----+----+-----+---
+// E0 | 04 | 00: first transaction data block
+// 80: subsequent transaction data block
+// | 00 | variable | variable
+//
+// Where the input for the first transaction block (first 255 bytes) is:
+//
+// Description | Length
+// -------------------------------------------------+----------
+// Number of BIP 32 derivations to perform (max 10) | 1 byte
+// First derivation index (big endian) | 4 bytes
+// ... | 4 bytes
+// Last derivation index (big endian) | 4 bytes
+// RLP transaction chunk | arbitrary
+//
+// And the input for subsequent transaction blocks (first 255 bytes) are:
+//
+// Description | Length
+// ----------------------+----------
+// RLP transaction chunk | arbitrary
+//
+// And the output data is:
+//
+// Description | Length
+// ------------+---------
+// signature V | 1 byte
+// signature R | 32 bytes
+// signature S | 32 bytes
+func (w *ledgerWallet) sign(derivationPath []uint32, address common.Address, tx *types.Transaction, chainID *big.Int) (*types.Transaction, error) {
+ // We need to modify the timeouts to account for user feedback
+ defer func(old time.Duration) { w.device.ReadTimeout = old }(w.device.ReadTimeout)
+ w.device.ReadTimeout = time.Minute
+
+ // Flatten the derivation path into the Ledger request
+ path := make([]byte, 1+4*len(derivationPath))
+ path[0] = byte(len(derivationPath))
+ for i, component := range derivationPath {
+ binary.BigEndian.PutUint32(path[1+4*i:], component)
+ }
+ // Create the transaction RLP based on whether legacy or EIP155 signing was requeste
+ var (
+ txrlp []byte
+ err error
+ )
+ if chainID == nil {
+ if txrlp, err = rlp.EncodeToBytes([]interface{}{tx.Nonce(), tx.GasPrice(), tx.Gas(), tx.To(), tx.Value(), tx.Data()}); err != nil {
+ return nil, err
+ }
+ } else {
+ if txrlp, err = rlp.EncodeToBytes([]interface{}{tx.Nonce(), tx.GasPrice(), tx.Gas(), tx.To(), tx.Value(), tx.Data(), chainID, big.NewInt(0), big.NewInt(0)}); err != nil {
+ return nil, err
+ }
+ }
+ payload := append(path, txrlp...)
+
+ // Send the request and wait for the response
+ var (
+ op = ledgerP1InitTransactionData
+ reply []byte
+ )
+ for len(payload) > 0 {
+ // Calculate the size of the next data chunk
+ chunk := 255
+ if chunk > len(payload) {
+ chunk = len(payload)
+ }
+ // Send the chunk over, ensuring it's processed correctly
+ reply, err = w.exchange(ledgerOpSignTransaction, op, 0, payload[:chunk])
+ if err != nil {
+ return nil, err
+ }
+ // Shift the payload and ensure subsequent chunks are marked as such
+ payload = payload[chunk:]
+ op = ledgerP1ContTransactionData
+ }
+ // Extract the Ethereum signature and do a sanity validation
+ if len(reply) != 65 {
+ return nil, errors.New("reply lacks signature")
+ }
+ signature := append(reply[1:], reply[0])
+
+ // 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] = (signature[64]-34)/2 - byte(chainID.Uint64())
+ }
+ // Inject the final signature into the transaction and sanity check the sender
+ signed, err := tx.WithSignature(signer, signature)
+ if err != nil {
+ return nil, err
+ }
+ sender, err := types.Sender(signer, signed)
+ if err != nil {
+ return nil, err
+ }
+ if sender != address {
+ return nil, fmt.Errorf("signer mismatch: expected %s, got %s", address.Hex(), sender.Hex())
+ }
+ return signed, nil
+}
+
+// exchange performs a data exchange with the Ledger wallet, sending it a message
+// and retrieving the response.
+//
+// The common transport header is defined as follows:
+//
+// Description | Length
+// --------------------------------------+----------
+// Communication channel ID (big endian) | 2 bytes
+// Command tag | 1 byte
+// Packet sequence index (big endian) | 2 bytes
+// Payload | arbitrary
+//
+// The Communication channel ID allows commands multiplexing over the same
+// physical link. It is not used for the time being, and should be set to 0101
+// to avoid compatibility issues with implementations ignoring a leading 00 byte.
+//
+// The Command tag describes the message content. Use TAG_APDU (0x05) for standard
+// APDU payloads, or TAG_PING (0x02) for a simple link test.
+//
+// The Packet sequence index describes the current sequence for fragmented payloads.
+// The first fragment index is 0x00.
+//
+// APDU Command payloads are encoded as follows:
+//
+// Description | Length
+// -----------------------------------
+// APDU length (big endian) | 2 bytes
+// APDU CLA | 1 byte
+// APDU INS | 1 byte
+// APDU P1 | 1 byte
+// APDU P2 | 1 byte
+// APDU length | 1 byte
+// Optional APDU data | arbitrary
+func (w *ledgerWallet) exchange(opcode ledgerOpcode, p1 ledgerParam1, p2 ledgerParam2, data []byte) ([]byte, error) {
+ // Construct the message payload, possibly split into multiple chunks
+ var chunks [][]byte
+ for left := data; len(left) > 0 || len(chunks) == 0; {
+ // Create the chunk header
+ var chunk []byte
+
+ if len(chunks) == 0 {
+ // The first chunk encodes the length and all the opcodes
+ chunk = []byte{0x00, 0x00, 0xe0, byte(opcode), byte(p1), byte(p2), byte(len(data))}
+ binary.BigEndian.PutUint16(chunk, uint16(5+len(data)))
+ }
+ // Append the data blob to the end of the chunk
+ space := 64 - len(chunk) - 5 // 5 == header size
+ if len(left) > space {
+ chunks, left = append(chunks, append(chunk, left[:space]...)), left[space:]
+ continue
+ }
+ chunks, left = append(chunks, append(chunk, left...)), nil
+ }
+ // Stream all the chunks to the device
+ for i, chunk := range chunks {
+ // Construct the new message to stream
+ header := []byte{0x01, 0x01, 0x05, 0x00, 0x00} // Channel ID and command tag appended
+ binary.BigEndian.PutUint16(header[3:], uint16(i))
+
+ msg := append(header, chunk...)
+
+ // Send over to the device
+ if glog.V(logger.Core) {
+ glog.Infof("-> %03d.%03d: %x", w.device.Bus, w.device.Address, msg)
+ }
+ if _, err := w.input.Write(msg); err != nil {
+ return nil, err
+ }
+ }
+ // Stream the reply back from the wallet in 64 byte chunks
+ var reply []byte
+ for {
+ // Read the next chunk from the Ledger wallet
+ chunk := make([]byte, 64)
+ if _, err := io.ReadFull(w.output, chunk); err != nil {
+ return nil, err
+ }
+ if glog.V(logger.Core) {
+ glog.Infof("<- %03d.%03d: %x", w.device.Bus, w.device.Address, chunk)
+ }
+ // Make sure the transport header matches
+ if chunk[0] != 0x01 || chunk[1] != 0x01 || chunk[2] != 0x05 {
+ return nil, fmt.Errorf("invalid reply header: %x", chunk[:3])
+ }
+ // If it's the first chunk, retrieve the total message length
+ if chunk[3] == 0x00 && chunk[4] == 0x00 {
+ reply = make([]byte, 0, int(binary.BigEndian.Uint16(chunk[5:7])))
+ chunk = chunk[7:]
+ } else {
+ chunk = chunk[5:]
+ }
+ // Append to the reply and stop when filled up
+ if left := cap(reply) - len(reply); left > len(chunk) {
+ reply = append(reply, chunk...)
+ } else {
+ reply = append(reply, chunk[:left]...)
+ break
+ }
+ }
+ return reply[:len(reply)-2], nil
+}