accounts, core, internal, node: Add support for smartcard wallets

accounts/hd.go

@@ -17,6 +17,7 @@
 package accounts
 
 import (
+	"encoding/json"
 	"errors"
 	"fmt"
 	"math"
@@ -133,3 +134,17 @@ func (path DerivationPath) String() string {
 	}
 	return result
 }
+
+func (path DerivationPath) MarshalJSON() ([]byte, error) {
+	return []byte(fmt.Sprintf("\"%s\"", path.String())), nil
+}
+
+func (dp *DerivationPath) UnmarshalJSON(b []byte) error {
+	var path string
+	var err error
+	if err = json.Unmarshal(b, &path); err != nil {
+		return err
+	}
+	*dp, err = ParseDerivationPath(path)
+	return err
+}

accounts/scwallet/apdu.go

+// Copyright 2018 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/>.
+
+package scwallet
+
+import (
+	"bytes"
+	"encoding/binary"
+)
+
+const (
+	CLA_ISO7816 = 0
+
+	INS_SELECT                = 0xA4
+	INS_GET_RESPONSE          = 0xC0
+	INS_PAIR                  = 0x12
+	INS_UNPAIR                = 0x13
+	INS_OPEN_SECURE_CHANNEL   = 0x10
+	INS_MUTUALLY_AUTHENTICATE = 0x11
+
+	SW1_GET_RESPONSE = 0x61
+	SW1_OK           = 0x90
+)
+
+// CommandAPDU represents an application data unit sent to a smartcard
+type CommandAPDU struct {
+	Cla, Ins, P1, P2 uint8  // Class, Instruction, Parameter 1, Parameter 2
+	Data             []byte // Command data
+	Le               uint8  // Command data length
+}
+
+// serialize serializes a command APDU.
+func (ca CommandAPDU) serialize() ([]byte, error) {
+	buf := new(bytes.Buffer)
+
+	if err := binary.Write(buf, binary.BigEndian, ca.Cla); err != nil {
+		return nil, err
+	}
+	if err := binary.Write(buf, binary.BigEndian, ca.Ins); err != nil {
+		return nil, err
+	}
+	if err := binary.Write(buf, binary.BigEndian, ca.P1); err != nil {
+		return nil, err
+	}
+	if err := binary.Write(buf, binary.BigEndian, ca.P2); err != nil {
+		return nil, err
+	}
+	if len(ca.Data) > 0 {
+		if err := binary.Write(buf, binary.BigEndian, uint8(len(ca.Data))); err != nil {
+			return nil, err
+		}
+		if err := binary.Write(buf, binary.BigEndian, ca.Data); err != nil {
+			return nil, err
+		}
+	}
+	if err := binary.Write(buf, binary.BigEndian, ca.Le); err != nil {
+		return nil, err
+	}
+	return buf.Bytes(), nil
+}
+
+// ResponseAPDU represents an application data unit received from a smart card
+type ResponseAPDU struct {
+	Data     []byte // response data
+	Sw1, Sw2 uint8  // status words 1 and 2
+}
+
+// deserialize deserializes a response APDU
+func (ra *ResponseAPDU) deserialize(data []byte) error {
+	ra.Data = make([]byte, len(data)-2)
+
+	buf := bytes.NewReader(data)
+	if err := binary.Read(buf, binary.BigEndian, &ra.Data); err != nil {
+		return err
+	}
+	if err := binary.Read(buf, binary.BigEndian, &ra.Sw1); err != nil {
+		return err
+	}
+	if err := binary.Read(buf, binary.BigEndian, &ra.Sw2); err != nil {
+		return err
+	}
+	return nil
+}

accounts/scwallet/hub.go

+// Copyright 2018 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/>.
+
+package scwallet
+
+import (
+	"encoding/json"
+	"io/ioutil"
+	"os"
+	"reflect"
+	"sync"
+	"time"
+
+	"github.com/ebfe/scard"
+	"github.com/ethereum/go-ethereum/accounts"
+	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/common/hexutil"
+	"github.com/ethereum/go-ethereum/event"
+	"github.com/ethereum/go-ethereum/log"
+)
+
+const Scheme = "pcsc"
+
+// refreshCycle is the maximum time between wallet refreshes (if USB hotplug
+// notifications don't work).
+const refreshCycle = 5 * time.Second
+
+// refreshThrottling is the minimum time between wallet refreshes to avoid thrashing.
+const refreshThrottling = 500 * time.Millisecond
+
+// SmartcardPairing contains information about a smart card we have paired with
+// or might pair withub.
+type SmartcardPairing struct {
+	PublicKey    []byte                                     `json:"publicKey"`
+	PairingIndex uint8                                      `json:"pairingIndex"`
+	PairingKey   []byte                                     `json:"pairingKey"`
+	Accounts     map[common.Address]accounts.DerivationPath `json:"accounts"`
+}
+
+// Hub is a accounts.Backend that can find and handle generic PC/SC hardware wallets.
+type Hub struct {
+	scheme string // Protocol scheme prefixing account and wallet URLs.
+
+	context     *scard.Context
+	datadir     string
+	pairings    map[string]SmartcardPairing
+	refreshed   time.Time               // Time instance when the list of wallets was last refreshed
+	wallets     map[string]*Wallet      // Mapping from reader names to wallet instances
+	updateFeed  event.Feed              // Event feed to notify wallet additions/removals
+	updateScope event.SubscriptionScope // Subscription scope tracking current live listeners
+	updating    bool                    // Whether the event notification loop is running
+
+	quit chan chan error
+
+	stateLock sync.Mutex // Protects the internals of the hub from racey access
+}
+
+var HubType = reflect.TypeOf(&Hub{})
+
+func (hub *Hub) readPairings() error {
+	hub.pairings = make(map[string]SmartcardPairing)
+	pairingFile, err := os.Open(hub.datadir + "/smartcards.json")
+	if err != nil {
+		if os.IsNotExist(err) {
+			return nil
+		}
+		return err
+	}
+
+	pairingData, err := ioutil.ReadAll(pairingFile)
+	if err != nil {
+		return err
+	}
+	var pairings []SmartcardPairing
+	if err := json.Unmarshal(pairingData, &pairings); err != nil {
+		return err
+	}
+
+	for _, pairing := range pairings {
+		hub.pairings[string(pairing.PublicKey)] = pairing
+	}
+	return nil
+}
+
+func (hub *Hub) writePairings() error {
+	pairingFile, err := os.OpenFile(hub.datadir+"/smartcards.json", os.O_RDWR|os.O_CREATE, 0755)
+	if err != nil {
+		return err
+	}
+
+	pairings := make([]SmartcardPairing, 0, len(hub.pairings))
+	for _, pairing := range hub.pairings {
+		pairings = append(pairings, pairing)
+	}
+
+	pairingData, err := json.Marshal(pairings)
+	if err != nil {
+		return err
+	}
+
+	if _, err := pairingFile.Write(pairingData); err != nil {
+		return err
+	}
+
+	return pairingFile.Close()
+}
+
+func (hub *Hub) getPairing(wallet *Wallet) *SmartcardPairing {
+	pairing, ok := hub.pairings[string(wallet.PublicKey)]
+	if ok {
+		return &pairing
+	}
+	return nil
+}
+
+func (hub *Hub) setPairing(wallet *Wallet, pairing *SmartcardPairing) error {
+	if pairing == nil {
+		delete(hub.pairings, string(wallet.PublicKey))
+	} else {
+		hub.pairings[string(wallet.PublicKey)] = *pairing
+	}
+	return hub.writePairings()
+}
+
+// NewHub creates a new hardware wallet manager for smartcards.
+func NewHub(scheme string, datadir string) (*Hub, error) {
+	context, err := scard.EstablishContext()
+	if err != nil {
+		return nil, err
+	}
+
+	hub := &Hub{
+		scheme:  scheme,
+		context: context,
+		datadir: datadir,
+		wallets: make(map[string]*Wallet),
+		quit:    make(chan chan error),
+	}
+
+	if err := hub.readPairings(); err != nil {
+		return nil, err
+	}
+
+	hub.refreshWallets()
+	return hub, nil
+}
+
+// Wallets implements accounts.Backend, returning all the currently tracked USB
+// devices that appear to be hardware wallets.
+func (hub *Hub) Wallets() []accounts.Wallet {
+	// Make sure the list of wallets is up to date
+	hub.stateLock.Lock()
+	defer hub.stateLock.Unlock()
+
+	hub.refreshWallets()
+
+	cpy := make([]accounts.Wallet, 0, len(hub.wallets))
+	for _, wallet := range hub.wallets {
+		if wallet != nil {
+			cpy = append(cpy, wallet)
+		}
+	}
+	return cpy
+}
+
+// refreshWallets scans the USB devices attached to the machine and updates the
+// list of wallets based on the found devices.
+func (hub *Hub) refreshWallets() {
+	elapsed := time.Since(hub.refreshed)
+	if elapsed < refreshThrottling {
+		return
+	}
+
+	readers, err := hub.context.ListReaders()
+	if err != nil {
+		log.Error("Error listing readers", "err", err)
+	}
+
+	events := []accounts.WalletEvent{}
+	seen := make(map[string]struct{})
+	for _, reader := range readers {
+		if wallet, ok := hub.wallets[reader]; ok {
+			// We already know about this card; check it's still present
+			if err := wallet.ping(); err != nil {
+				log.Debug("Got error pinging wallet", "reader", reader, "err", err)
+			} else {
+				seen[reader] = struct{}{}
+			}
+			continue
+		}
+		seen[reader] = struct{}{}
+
+		card, err := hub.context.Connect(reader, scard.ShareShared, scard.ProtocolAny)
+		if err != nil {
+			log.Debug("Error opening card", "reader", reader, "err", err)
+			continue
+		}
+
+		wallet := NewWallet(hub, card)
+		err = wallet.connect()
+		if err != nil {
+			log.Debug("Error connecting to wallet", "reader", reader, "err", err)
+			card.Disconnect(scard.LeaveCard)
+			continue
+		}
+
+		hub.wallets[reader] = wallet
+		events = append(events, accounts.WalletEvent{Wallet: wallet, Kind: accounts.WalletArrived})
+		log.Info("Found new smartcard wallet", "reader", reader, "publicKey", hexutil.Encode(wallet.PublicKey[:4]))
+	}
+
+	// Remove any wallets we no longer see
+	for k, wallet := range hub.wallets {
+		if _, ok := seen[k]; !ok {
+			log.Info("Wallet disconnected", "pubkey", hexutil.Encode(wallet.PublicKey[:4]), "reader", k)
+			wallet.Close()
+			events = append(events, accounts.WalletEvent{Wallet: wallet, Kind: accounts.WalletDropped})
+			delete(hub.wallets, k)
+		}
+	}
+
+	for _, event := range events {
+		hub.updateFeed.Send(event)
+	}
+	hub.refreshed = time.Now()
+}
+
+// Subscribe implements accounts.Backend, creating an async subscription to
+// receive notifications on the addition or removal of wallets.
+func (hub *Hub) Subscribe(sink chan<- accounts.WalletEvent) event.Subscription {
+	// We need the mutex to reliably start/stop the update loop
+	hub.stateLock.Lock()
+	defer hub.stateLock.Unlock()
+
+	// Subscribe the caller and track the subscriber count
+	sub := hub.updateScope.Track(hub.updateFeed.Subscribe(sink))
+
+	// Subscribers require an active notification loop, start it
+	if !hub.updating {
+		hub.updating = true
+		go hub.updater()
+	}
+	return sub
+}
+
+// updater is responsible for maintaining an up-to-date list of wallets managed
+// by the hub, and for firing wallet addition/removal events.
+func (hub *Hub) updater() {
+	for {
+		time.Sleep(refreshCycle)
+
+		// Run the wallet refresher
+		hub.stateLock.Lock()
+		hub.refreshWallets()
+
+		// If all our subscribers left, stop the updater
+		if hub.updateScope.Count() == 0 {
+			hub.updating = false
+			hub.stateLock.Unlock()
+			return
+		}
+		hub.stateLock.Unlock()
+	}
+}

accounts/scwallet/securechannel.go

+// Copyright 2018 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/>.
+
+package scwallet
+
+import (
+	//"crypto/ecdsa"
+	"bytes"
+	"crypto/aes"
+	"crypto/cipher"
+	"crypto/rand"
+	"crypto/sha256"
+	"crypto/sha512"
+	"fmt"
+	//"math/big"
+	"github.com/ebfe/scard"
+	"github.com/ethereum/go-ethereum/crypto"
+	ecdh "github.com/wsddn/go-ecdh"
+)
+
+const (
+	MAX_PAYLOAD_SIZE   = 223
+	PAIR_P1_FIRST_STEP = 0
+	PAIR_P1_LAST_STEP  = 1
+
+	SC_SECRET_LENGTH = 32
+	SC_BLOCK_SIZE    = 16
+)
+
+// SecureChannelSession enables secure communication with a hardware wallet
+type SecureChannelSession struct {
+	card          *scard.Card // A handle to the smartcard for communication
+	secret        []byte      // A shared secret generated from our ECDSA keys
+	publicKey     []byte      // Our own ephemeral public key
+	PairingKey    []byte      // A permanent shared secret for a pairing, if present
+	sessionEncKey []byte      // The current session encryption key
+	sessionMacKey []byte      // The current session MAC key
+	iv            []byte      // The current IV
+	PairingIndex  uint8       // The pairing index
+}
+
+// NewSecureChannelSession creates a new secure channel for the given card and public key
+func NewSecureChannelSession(card *scard.Card, keyData []byte) (*SecureChannelSession, error) {
+	// Generate an ECDSA keypair for ourselves
+	gen := ecdh.NewEllipticECDH(crypto.S256())
+	private, public, err := gen.GenerateKey(rand.Reader)
+	if err != nil {
+		return nil, err
+	}
+
+	cardPublic, ok := gen.Unmarshal(keyData)
+	if !ok {
+		return nil, fmt.Errorf("Could not unmarshal public key from card")
+	}
+
+	secret, err := gen.GenerateSharedSecret(private, cardPublic)
+	if err != nil {
+		return nil, err
+	}
+
+	return &SecureChannelSession{
+		card:      card,
+		secret:    secret,
+		publicKey: gen.Marshal(public),
+	}, nil
+}
+
+// Pair establishes a new pairing with the smartcard
+func (s *SecureChannelSession) Pair(sharedSecret []byte) error {
+	secretHash := sha256.Sum256(sharedSecret)
+
+	challenge := make([]byte, 32)
+	if _, err := rand.Read(challenge); err != nil {
+		return err
+	}
+
+	response, err := s.pair(PAIR_P1_FIRST_STEP, challenge)
+	if err != nil {
+		return err
+	}
+
+	md := sha256.New()
+	md.Write(secretHash[:])
+	md.Write(challenge)
+
+	expectedCryptogram := md.Sum(nil)
+	cardCryptogram := response.Data[:32]
+	cardChallenge := response.Data[32:]
+
+	if !bytes.Equal(expectedCryptogram, cardCryptogram) {
+		return fmt.Errorf("Invalid card cryptogram")
+	}
+
+	md.Reset()
+	md.Write(secretHash[:])
+	md.Write(cardChallenge)
+	response, err = s.pair(PAIR_P1_LAST_STEP, md.Sum(nil))
+	if err != nil {
+		return err
+	}
+
+	md.Reset()
+	md.Write(secretHash[:])
+	md.Write(response.Data[1:])
+	s.PairingKey = md.Sum(nil)
+	s.PairingIndex = response.Data[0]
+
+	return nil
+}
+
+// Unpair disestablishes an existing pairing
+func (s *SecureChannelSession) Unpair() error {
+	if s.PairingKey == nil {
+		return fmt.Errorf("Cannot unpair: not paired")
+	}
+
+	_, err := s.TransmitEncrypted(CLA_SCWALLET, INS_UNPAIR, s.PairingIndex, 0, []byte{})
+	if err != nil {
+		return err
+	}
+	s.PairingKey = nil
+	// Close channel
+	s.iv = nil
+	return nil
+}
+
+// Open initializes the secure channel
+func (s *SecureChannelSession) Open() error {
+	if s.iv != nil {
+		return fmt.Errorf("Session already opened")
+	}
+
+	response, err := s.open()
+	if err != nil {
+		return err
+	}
+
+	// Generate the encryption/mac key by hashing our shared secret,
+	// pairing key, and the first bytes returned from the Open APDU.
+	md := sha512.New()
+	md.Write(s.secret)
+	md.Write(s.PairingKey)
+	md.Write(response.Data[:SC_SECRET_LENGTH])
+	keyData := md.Sum(nil)
+	s.sessionEncKey = keyData[:SC_SECRET_LENGTH]
+	s.sessionMacKey = keyData[SC_SECRET_LENGTH : SC_SECRET_LENGTH*2]
+
+	// The IV is the last bytes returned from the Open APDU.
+	s.iv = response.Data[SC_SECRET_LENGTH:]
+
+	if err := s.mutuallyAuthenticate(); err != nil {
+		return err
+	}
+
+	return nil
+}
+
+// mutuallyAuthenticate is an internal method to authenticate both ends of the
+// connection.
+func (s *SecureChannelSession) mutuallyAuthenticate() error {
+	data := make([]byte, SC_SECRET_LENGTH)
+	if _, err := rand.Read(data); err != nil {
+		return err
+	}
+
+	response, err := s.TransmitEncrypted(CLA_SCWALLET, INS_MUTUALLY_AUTHENTICATE, 0, 0, data)
+	if err != nil {
+		return err
+	}
+	if response.Sw1 != 0x90 || response.Sw2 != 0x00 {
+		return fmt.Errorf("Got unexpected response from MUTUALLY_AUTHENTICATE: 0x%x%x", response.Sw1, response.Sw2)
+	}
+
+	if len(response.Data) != SC_SECRET_LENGTH {
+		return fmt.Errorf("Response from MUTUALLY_AUTHENTICATE was %d bytes, expected %d", len(response.Data), SC_SECRET_LENGTH)
+	}
+
+	return nil
+}
+
+// open is an internal method that sends an open APDU
+func (s *SecureChannelSession) open() (*ResponseAPDU, error) {
+	return transmit(s.card, &CommandAPDU{
+		Cla:  CLA_SCWALLET,
+		Ins:  INS_OPEN_SECURE_CHANNEL,
+		P1:   s.PairingIndex,
+		P2:   0,
+		Data: s.publicKey,
+		Le:   0,
+	})
+}
+
+// pair is an internal method that sends a pair APDU
+func (s *SecureChannelSession) pair(p1 uint8, data []byte) (*ResponseAPDU, error) {
+	return transmit(s.card, &CommandAPDU{
+		Cla:  CLA_SCWALLET,
+		Ins:  INS_PAIR,
+		P1:   p1,
+		P2:   0,
+		Data: data,
+		Le:   0,
+	})
+}
+
+// TransmitEncrypted sends an encrypted message, and decrypts and returns the response
+func (s *SecureChannelSession) TransmitEncrypted(cla, ins, p1, p2 byte, data []byte) (*ResponseAPDU, error) {
+	if s.iv == nil {
+		return nil, fmt.Errorf("Channel not open")
+	}
+
+	data, err := s.encryptAPDU(data)
+	if err != nil {
+		return nil, err
+	}
+	meta := []byte{cla, ins, p1, p2, byte(len(data) + SC_BLOCK_SIZE), 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0}
+	if err = s.updateIV(meta, data); err != nil {
+		return nil, err
+	}
+
+	fulldata := make([]byte, len(s.iv)+len(data))
+	copy(fulldata, s.iv)
+	copy(fulldata[len(s.iv):], data)
+
+	response, err := transmit(s.card, &CommandAPDU{
+		Cla:  cla,
+		Ins:  ins,
+		P1:   p1,
+		P2:   p2,
+		Data: fulldata,
+	})
+	if err != nil {
+		return nil, err
+	}
+
+	rmeta := []byte{byte(len(response.Data)), 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0}
+	rmac := response.Data[:len(s.iv)]
+	rdata := response.Data[len(s.iv):]
+	plainData, err := s.decryptAPDU(rdata)
+	if err != nil {
+		return nil, err
+	}
+
+	if err = s.updateIV(rmeta, rdata); err != nil {
+		return nil, err
+	}
+	if !bytes.Equal(s.iv, rmac) {
+		return nil, fmt.Errorf("Invalid MAC in response")
+	}
+
+	rapdu := &ResponseAPDU{}
+	rapdu.deserialize(plainData)
+
+	if rapdu.Sw1 != SW1_OK {
+		return nil, fmt.Errorf("Unexpected response status Cla=0x%x, Ins=0x%x, Sw=0x%x%x", cla, ins, rapdu.Sw1, rapdu.Sw2)
+	}
+
+	return rapdu, nil
+}
+
+// encryptAPDU is an internal method that serializes and encrypts an APDU
+func (s *SecureChannelSession) encryptAPDU(data []byte) ([]byte, error) {
+	if len(data) > MAX_PAYLOAD_SIZE {
+		return nil, fmt.Errorf("Payload of %d bytes exceeds maximum of %d", len(data), MAX_PAYLOAD_SIZE)
+	}
+	data = pad(data, 0x80)
+
+	ret := make([]byte, len(data))
+
+	a, err := aes.NewCipher(s.sessionEncKey)
+	if err != nil {
+		return nil, err
+	}
+	crypter := cipher.NewCBCEncrypter(a, s.iv)
+	crypter.CryptBlocks(ret, data)
+	return ret, nil
+}
+
+// pad applies message padding to a 16 byte boundary
+func pad(data []byte, terminator byte) []byte {
+	padded := make([]byte, (len(data)/16+1)*16)
+	copy(padded, data)
+	padded[len(data)] = terminator
+	return padded
+}
+
+// decryptAPDU is an internal method that decrypts and deserializes an APDU
+func (s *SecureChannelSession) decryptAPDU(data []byte) ([]byte, error) {
+	a, err := aes.NewCipher(s.sessionEncKey)
+	if err != nil {
+		return nil, err
+	}
+
+	ret := make([]byte, len(data))
+
+	crypter := cipher.NewCBCDecrypter(a, s.iv)
+	crypter.CryptBlocks(ret, data)
+	return unpad(ret, 0x80)
+}
+
+// unpad strips padding from a message
+func unpad(data []byte, terminator byte) ([]byte, error) {
+	for i := 1; i <= 16; i++ {
+		switch data[len(data)-i] {
+		case 0:
+			continue
+		case terminator:
+			return data[:len(data)-i], nil
+		default:
+			return nil, fmt.Errorf("Expected end of padding, got %d", data[len(data)-i])
+		}
+	}
+	return nil, fmt.Errorf("Expected end of padding, got 0")
+}
+
+// updateIV is an internal method that updates the initialization vector after
+// each message exchanged.
+func (s *SecureChannelSession) updateIV(meta, data []byte) error {
+	data = pad(data, 0)
+	a, err := aes.NewCipher(s.sessionMacKey)
+	if err != nil {
+		return err
+	}
+	crypter := cipher.NewCBCEncrypter(a, make([]byte, 16))
+	crypter.CryptBlocks(meta, meta)
+	crypter.CryptBlocks(data, data)
+	// The first 16 bytes of the last block is the MAC
+	s.iv = data[len(data)-32 : len(data)-16]
+	return nil
+}

accounts/scwallet/wallet.go

+// Copyright 2018 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/>.
+
+package scwallet
+
+import (
+	"bytes"
+	"context"
+	"crypto/hmac"
+	"crypto/sha256"
+	"crypto/sha512"
+	"encoding/asn1"
+	"encoding/binary"
+	"errors"
+	"fmt"
+	"math/big"
+	"strings"
+	"sync"
+	"time"
+
+	"github.com/ebfe/scard"
+	ethereum "github.com/ethereum/go-ethereum"
+	"github.com/ethereum/go-ethereum/accounts"
+	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/core/types"
+	"github.com/ethereum/go-ethereum/crypto"
+	"github.com/ethereum/go-ethereum/crypto/secp256k1"
+	"github.com/ethereum/go-ethereum/log"
+)
+
+var (
+	APPLET_AID              = []byte{0x53, 0x74, 0x61, 0x74, 0x75, 0x73, 0x57, 0x61, 0x6C, 0x6C, 0x65, 0x74, 0x41, 0x70, 0x70}
+	AlreadyOpenError        = errors.New("Wallet already open")
+	PairingRequiredError    = errors.New("Pairing required with personal.openWallet(puk)")
+	PinRequiredError        = errors.New("Must unlock with personal.openWallet(pin)")
+	PubkeyMismatchError     = errors.New("Could not recover matching public key from signature")
+	WalletChangedError      = errors.New("Smartcard has been changed")
+	DerivationSignatureHash = sha256.Sum256([]byte("STATUS KEY DERIVATION"))
+)
+
+const (
+	CLA_SCWALLET             = 0x80
+	INS_VERIFY_PIN           = 0x20
+	INS_EXPORT_KEY           = 0xC2
+	INS_SIGN                 = 0xC0
+	INS_LOAD_KEY             = 0xD0
+	INS_DERIVE_KEY           = 0xD1
+	INS_STATUS               = 0xF2
+	DERIVE_P1_ASSISTED       = uint8(0x01)
+	DERIVE_P1_APPEND         = uint8(0x80)
+	DERIVE_P2_KEY_PATH       = uint8(0x00)
+	DERIVE_P2_PUBLIC_KEY     = uint8(0x01)
+	STATUS_P1_WALLET_STATUS  = uint8(0x00)
+	STATUS_P1_PATH           = uint8(0x01)
+	SIGN_P1_PRECOMPUTED_HASH = uint8(0x01)
+	SIGN_P2_ONLY_BLOCK       = uint8(0x81)
+	EXPORT_P1_ANY            = uint8(0x00)
+	EXPORT_P2_PUBKEY         = uint8(0x01)
+
+	// Minimum time to wait between self derivation attempts, even it the user is
+	// requesting accounts like crazy.
+	selfDeriveThrottling = time.Second
+)
+
+// Wallet represents a smartcard wallet instance.
+type Wallet struct {
+	Hub       *Hub   // A handle to the Hub that instantiated this wallet.
+	PublicKey []byte // The wallet's public key (used for communication and identification, not signing!)
+
+	lock           sync.Mutex                // Lock that gates access to struct fields and communication with the card
+	card           *scard.Card               // A handle to the smartcard interface for the wallet.
+	session        *Session                  // The secure communication session with the card
+	log            log.Logger                // Contextual logger to tag the base with its id
+	deriveNextPath accounts.DerivationPath   // Next derivation path for account auto-discovery
+	deriveNextAddr common.Address            // Next derived account address for auto-discovery
+	deriveChain    ethereum.ChainStateReader // Blockchain state reader to discover used account with
+	deriveReq      chan chan struct{}        // Channel to request a self-derivation on
+	deriveQuit     chan chan error           // Channel to terminate the self-deriver with
+}
+
+// NewWallet constructs and returns a new Wallet instance.
+func NewWallet(hub *Hub, card *scard.Card) *Wallet {
+	wallet := &Wallet{
+		Hub:  hub,
+		card: card,
+	}
+	return wallet
+}
+
+// transmit sends an APDU to the smartcard and receives and decodes the response.
+// It automatically handles requests by the card to fetch the return data separately,
+// and returns an error if the response status code is not success.
+func transmit(card *scard.Card, command *CommandAPDU) (*ResponseAPDU, error) {
+	data, err := command.serialize()
+	if err != nil {
+		return nil, err
+	}
+
+	responseData, err := card.Transmit(data)
+	if err != nil {
+		return nil, err
+	}
+
+	response := new(ResponseAPDU)
+	if err = response.deserialize(responseData); err != nil {
+		return nil, err
+	}
+
+	// Are we being asked to fetch the response separately?
+	if response.Sw1 == SW1_GET_RESPONSE && (command.Cla != CLA_ISO7816 || command.Ins != INS_GET_RESPONSE) {
+		return transmit(card, &CommandAPDU{
+			Cla:  CLA_ISO7816,
+			Ins:  INS_GET_RESPONSE,
+			P1:   0,
+			P2:   0,
+			Data: nil,
+			Le:   response.Sw2,
+		})
+	}
+
+	if response.Sw1 != SW1_OK {
+		return nil, fmt.Errorf("Unexpected insecure response status Cla=0x%x, Ins=0x%x, Sw=0x%x%x", command.Cla, command.Ins, response.Sw1, response.Sw2)
+	}
+
+	return response, nil
+}
+
+// applicationInfo encodes information about the smartcard application - its
+// instance UID and public key.
+type applicationInfo struct {
+	InstanceUID []byte `asn1:"tag:15"`
+	PublicKey   []byte `asn1:"tag:0"`
+}
+
+// connect connects to the wallet application and establishes a secure channel with it.
+// must be called before any other interaction with the wallet.
+func (w *Wallet) connect() error {
+	w.lock.Lock()
+	defer w.lock.Unlock()
+
+	appinfo, err := w.doselect()
+	if err != nil {
+		return err
+	}
+
+	channel, err := NewSecureChannelSession(w.card, appinfo.PublicKey)
+	if err != nil {
+		return err
+	}
+
+	w.PublicKey = appinfo.PublicKey
+	w.log = log.New("url", w.URL())
+	w.session = &Session{
+		Wallet:  w,
+		Channel: channel,
+	}
+	return nil
+}
+
+// doselect is an internal (unlocked) function to send a SELECT APDU to the card.
+func (w *Wallet) doselect() (*applicationInfo, error) {
+	response, err := transmit(w.card, &CommandAPDU{
+		Cla:  CLA_ISO7816,
+		Ins:  INS_SELECT,
+		P1:   4,
+		P2:   0,
+		Data: APPLET_AID,
+	})
+	if err != nil {
+		return nil, err
+	}
+
+	appinfo := new(applicationInfo)
+	if _, err := asn1.UnmarshalWithParams(response.Data, appinfo, "tag:4"); err != nil {
+		return nil, err
+	}
+	return appinfo, nil
+}
+
+// ping checks the card's status and returns an error if unsuccessful.
+func (w *Wallet) ping() error {
+	w.lock.Lock()
+	defer w.lock.Unlock()
+
+	if !w.session.paired() {
+		// We can't ping if not paired
+		return nil
+	}
+
+	_, err := w.session.getWalletStatus()
+	if err != nil {
+		return err
+	}
+	return nil
+}
+
+// release releases any resources held by an open wallet instance.
+func (w *Wallet) release() error {
+	if w.session != nil {
+		return w.session.release()
+	}
+	return nil
+}
+
+// pair is an internal (unlocked) function for establishing a new pairing
+// with the wallet.
+func (w *Wallet) pair(puk []byte) error {
+	if w.session.paired() {
+		return fmt.Errorf("Wallet already paired")
+	}
+
+	pairing, err := w.session.pair(puk)
+	if err != nil {
+		return err
+	}
+
+	if err = w.Hub.setPairing(w, &pairing); err != nil {
+		return err
+	}
+
+	return w.session.authenticate(pairing)
+}
+
+// Unpair deletes an existing wallet pairing.
+func (w *Wallet) Unpair(pin []byte) error {
+	w.lock.Lock()
+	defer w.lock.Unlock()
+
+	if !w.session.paired() {
+		return fmt.Errorf("Wallet %x not paired", w.PublicKey)
+	}
+
+	if err := w.session.verifyPin(pin); err != nil {
+		return fmt.Errorf("Error verifying pin: %s", err)
+	}
+
+	if err := w.session.unpair(); err != nil {
+		return fmt.Errorf("Error unpairing: %s", err)
+	}
+
+	if err := w.Hub.setPairing(w, nil); err != nil {
+		return err
+	}
+
+	return nil
+}
+
+// URL retrieves the canonical path under which this wallet is reachable. It is
+// user by upper layers to define a sorting order over all wallets from multiple
+// backends.
+func (w *Wallet) URL() accounts.URL {
+	return accounts.URL{
+		Scheme: w.Hub.scheme,
+		Path:   fmt.Sprintf("%x", w.PublicKey[1:3]),
+	}
+}
+
+// Status returns a textual status to aid the user in the current state of the
+// wallet. It also returns an error indicating any failure the wallet might have
+// encountered.
+func (w *Wallet) Status() (string, error) {
+	w.lock.Lock()
+	defer w.lock.Unlock()
+
+	if !w.session.paired() {
+		return "Unpaired", nil
+	}
+
+	status, err := w.session.getWalletStatus()
+	if err != nil {
+		return "Error", err
+	}
+
+	if w.session.verified {
+		return fmt.Sprintf("Open, %s", status), nil
+	} else {
+		return fmt.Sprintf("Locked, %s", status), nil
+	}
+}
+
+// Open initializes access to a wallet instance. It is not meant to unlock or
+// decrypt account keys, rather simply to establish a connection to hardware
+// wallets and/or to access derivation seeds.
+//
+// The passphrase parameter may or may not be used by the implementation of a
+// particular wallet instance. The reason there is no passwordless open method
+// is to strive towards a uniform wallet handling, oblivious to the different
+// backend providers.
+//
+// Please note, if you open a wallet, you must close it to release any allocated
+// resources (especially important when working with hardware wallets).
+func (w *Wallet) Open(passphrase string) error {
+	w.lock.Lock()
+	defer w.lock.Unlock()
+
+	if w.session.verified {
+		// Already open
+		return AlreadyOpenError
+	}
+
+	if !w.session.paired() {
+		// Unpaired.
+		if pairing := w.Hub.getPairing(w); pairing != nil {
+			// Authenticate with the existing pairing.
+			if err := w.session.authenticate(*pairing); err != nil {
+				return fmt.Errorf("Could not authenticate with paired card %x: %s", w.PublicKey[:4], err)
+			}
+		} else if passphrase != "" {
+			// Establish a new pairing
+			return w.pair([]byte(passphrase))
+		} else {
+			return PairingRequiredError
+		}
+	}
+
+	if passphrase == "" {
+		return PinRequiredError
+	}
+	// Verify pin
+	if err := w.session.verifyPin([]byte(passphrase)); err != nil {
+		return err
+	}
+
+	w.deriveReq = make(chan chan struct{})
+	w.deriveQuit = make(chan chan error)
+
+	go w.selfDerive()
+
+	// Notify anyone listening for wallet events that a new device is accessible
+	go w.Hub.updateFeed.Send(accounts.WalletEvent{Wallet: w, Kind: accounts.WalletOpened})
+
+	return nil
+}
+
+// Close stops and closes the wallet, freeing any resources.
+func (w *Wallet) Close() error {
+	// Ensure the wallet was opened
+	w.lock.Lock()
+	dQuit := w.deriveQuit
+	w.lock.Unlock()
+
+	// Terminate the self-derivations
+	var derr error
+	if dQuit != nil {
+		errc := make(chan error)
+		dQuit <- errc
+		derr = <-errc // Save for later, we *must* close the USB
+	}
+	// Terminate the device connection
+	w.lock.Lock()
+	defer w.lock.Unlock()
+
+	w.deriveQuit = nil
+	w.deriveReq = nil
+
+	if err := w.release(); err != nil {
+		return err
+	}
+	return derr
+}
+
+// selfDerive is an account derivation loop that upon request attempts to find
+// new non-zero accounts.
+func (w *Wallet) selfDerive() {
+	w.log.Debug("Smartcard wallet self-derivation started")
+	defer w.log.Debug("Smartcard wallet self-derivation stopped")
+
+	// Execute self-derivations until termination or error
+	var (
+		reqc chan struct{}
+		errc chan error
+		err  error
+	)
+	for errc == nil && err == nil {
+		// Wait until either derivation or termination is requested
+		select {
+		case errc = <-w.deriveQuit:
+			// Termination requested
+			continue
+		case reqc = <-w.deriveReq:
+			// Account discovery requested
+		}
+		// Derivation needs a chain and device access, skip if either unavailable
+		w.lock.Lock()
+		if w.session == nil || w.deriveChain == nil {
+			w.lock.Unlock()
+			reqc <- struct{}{}
+			continue
+		}
+		pairing := w.Hub.getPairing(w)
+
+		// Device lock obtained, derive the next batch of accounts
+		var (
+			paths       []accounts.DerivationPath
+			nextAccount accounts.Account
+			nextAddr    = w.deriveNextAddr
+			nextPath    = w.deriveNextPath
+
+			context = context.Background()
+		)
+		for empty := false; !empty; {
+			// Retrieve the next derived Ethereum account
+			if nextAddr == (common.Address{}) {
+				if nextAccount, err = w.session.derive(nextPath); err != nil {
+					w.log.Warn("Smartcard wallet account derivation failed", "err", err)
+					break
+				}
+				nextAddr = nextAccount.Address
+			}
+			// Check the account's status against the current chain state
+			var (
+				balance *big.Int
+				nonce   uint64
+			)
+			balance, err = w.deriveChain.BalanceAt(context, nextAddr, nil)
+			if err != nil {
+				w.log.Warn("Smartcard wallet balance retrieval failed", "err", err)
+				break
+			}
+			nonce, err = w.deriveChain.NonceAt(context, nextAddr, nil)
+			if err != nil {
+				w.log.Warn("Smartcard wallet nonce retrieval failed", "err", err)
+				break
+			}
+			// If the next account is empty, stop self-derivation, but add it nonetheless
+			if balance.Sign() == 0 && nonce == 0 {
+				empty = true
+			}
+			// We've just self-derived a new account, start tracking it locally
+			path := make(accounts.DerivationPath, len(nextPath))
+			copy(path[:], nextPath[:])
+			paths = append(paths, path)
+
+			// Display a log message to the user for new (or previously empty accounts)
+			if _, known := pairing.Accounts[nextAddr]; !known || (!empty && nextAddr == w.deriveNextAddr) {
+				w.log.Info("Smartcard wallet discovered new account", "address", nextAccount.Address, "path", path, "balance", balance, "nonce", nonce)
+			}
+			pairing.Accounts[nextAddr] = path
+
+			// Fetch the next potential account
+			if !empty {
+				nextAddr = common.Address{}
+				nextPath[len(nextPath)-1]++
+			}
+		}
+
+		// If there are new accounts, write them out
+		if len(paths) > 0 {
+			err = w.Hub.setPairing(w, pairing)
+		}
+
+		// Shift the self-derivation forward
+		w.deriveNextAddr = nextAddr
+		w.deriveNextPath = nextPath
+
+		// Self derivation complete, release device lock
+		w.lock.Unlock()
+
+		// Notify the user of termination and loop after a bit of time (to avoid trashing)
+		reqc <- struct{}{}
+		if err == nil {
+			select {
+			case errc = <-w.deriveQuit:
+				// Termination requested, abort
+			case <-time.After(selfDeriveThrottling):
+				// Waited enough, willing to self-derive again
+			}
+		}
+	}
+	// In case of error, wait for termination
+	if err != nil {
+		w.log.Debug("Smartcard wallet self-derivation failed", "err", err)
+		errc = <-w.deriveQuit
+	}
+	errc <- err
+}
+
+// Accounts retrieves the list of signing accounts the wallet is currently aware
+// of. For hierarchical deterministic wallets, the list will not be exhaustive,
+// rather only contain the accounts explicitly pinned during account derivation.
+func (w *Wallet) Accounts() []accounts.Account {
+	// Attempt self-derivation if it's running
+	reqc := make(chan struct{}, 1)
+	select {
+	case w.deriveReq <- reqc:
+		// Self-derivation request accepted, wait for it
+		<-reqc
+	default:
+		// Self-derivation offline, throttled or busy, skip
+	}
+
+	w.lock.Lock()
+	defer w.lock.Unlock()
+
+	if pairing := w.Hub.getPairing(w); pairing != nil {
+		ret := make([]accounts.Account, 0, len(pairing.Accounts))
+		for address, path := range pairing.Accounts {
+			ret = append(ret, w.makeAccount(address, path))
+		}
+		return ret
+	}
+	return nil
+}
+
+func (w *Wallet) makeAccount(address common.Address, path accounts.DerivationPath) accounts.Account {
+	return accounts.Account{
+		Address: address,
+		URL: accounts.URL{
+			Scheme: w.Hub.scheme,
+			Path:   fmt.Sprintf("%x/%s", w.PublicKey[1:3], path.String()),
+		},
+	}
+}
+
+// Contains returns whether an account is part of this particular wallet or not.
+func (w *Wallet) Contains(account accounts.Account) bool {
+	if pairing := w.Hub.getPairing(w); pairing != nil {
+		_, ok := pairing.Accounts[account.Address]
+		return ok
+	}
+	return false
+}
+
+// Initialize installs a keypair generated from the provided key into the wallet.
+func (w *Wallet) Initialize(seed []byte) error {
+	w.lock.Lock()
+	defer w.lock.Unlock()
+
+	return w.session.initialize(seed)
+}
+
+// Derive attempts to explicitly derive a hierarchical deterministic account at
+// the specified derivation path. If requested, the derived account will be added
+// to the wallet's tracked account list.
+func (w *Wallet) Derive(path accounts.DerivationPath, pin bool) (accounts.Account, error) {
+	w.lock.Lock()
+	defer w.lock.Unlock()
+
+	account, err := w.session.derive(path)
+	if err != nil {
+		return accounts.Account{}, err
+	}
+
+	if pin {
+		pairing := w.Hub.getPairing(w)
+		pairing.Accounts[account.Address] = path
+		if err := w.Hub.setPairing(w, pairing); err != nil {
+			return accounts.Account{}, err
+		}
+	}
+
+	return account, nil
+}
+
+// SelfDerive sets a base account derivation path from which the wallet attempts
+// to discover non zero accounts and automatically add them to list of tracked
+// accounts.
+//
+// Note, self derivaton will increment the last component of the specified path
+// opposed to decending into a child path to allow discovering accounts starting
+// from non zero components.
+//
+// You can disable automatic account discovery by calling SelfDerive with a nil
+// chain state reader.
+func (w *Wallet) SelfDerive(base accounts.DerivationPath, chain ethereum.ChainStateReader) {
+	w.lock.Lock()
+	defer w.lock.Unlock()
+
+	w.deriveNextPath = make(accounts.DerivationPath, len(base))
+	copy(w.deriveNextPath[:], base[:])
+
+	w.deriveNextAddr = common.Address{}
+	w.deriveChain = chain
+}
+
+// SignHash requests the wallet to sign the given hash.
+//
+// It looks up the account specified either solely via its address contained within,
+// or optionally with the aid of any location metadata from the embedded URL field.
+//
+// If the wallet requires additional authentication to sign the request (e.g.
+// a password to decrypt the account, or a PIN code o verify the transaction),
+// an AuthNeededError instance will be returned, containing infos for the user
+// about which fields or actions are needed. The user may retry by providing
+// the needed details via SignHashWithPassphrase, or by other means (e.g. unlock
+// the account in a keystore).
+func (w *Wallet) SignHash(account accounts.Account, hash []byte) ([]byte, error) {
+	w.lock.Lock()
+	defer w.lock.Unlock()
+
+	path, err := w.findAccountPath(account)
+	if err != nil {
+		return nil, err
+	}
+
+	return w.session.sign(path, hash)
+}
+
+// SignTx requests the wallet to sign the given transaction.
+//
+// It looks up the account specified either solely via its address contained within,
+// or optionally with the aid of any location metadata from the embedded URL field.
+//
+// If the wallet requires additional authentication to sign the request (e.g.
+// a password to decrypt the account, or a PIN code o verify the transaction),
+// an AuthNeededError instance will be returned, containing infos for the user
+// about which fields or actions are needed. The user may retry by providing
+// the needed details via SignTxWithPassphrase, or by other means (e.g. unlock
+// the account in a keystore).
+func (w *Wallet) SignTx(account accounts.Account, tx *types.Transaction, chainID *big.Int) (*types.Transaction, error) {
+	signer := types.NewEIP155Signer(chainID)
+	hash := signer.Hash(tx)
+	sig, err := w.SignHash(account, hash[:])
+	if err != nil {
+		return nil, err
+	}
+	return tx.WithSignature(signer, sig)
+}
+
+// SignHashWithPassphrase requests the wallet to sign the given hash with the
+// given passphrase as extra authentication information.
+//
+// It looks up the account specified either solely via its address contained within,
+// or optionally with the aid of any location metadata from the embedded URL field.
+func (w *Wallet) SignHashWithPassphrase(account accounts.Account, passphrase string, hash []byte) ([]byte, error) {
+	if !w.session.verified {
+		if err := w.Open(passphrase); err != nil {
+			return nil, err
+		}
+	}
+
+	return w.SignHash(account, hash)
+}
+
+// SignTxWithPassphrase requests the wallet to sign the given transaction, with the
+// given passphrase as extra authentication information.
+//
+// It looks up the account specified either solely via its address contained within,
+// or optionally with the aid of any location metadata from the embedded URL field.
+func (w *Wallet) SignTxWithPassphrase(account accounts.Account, passphrase string, tx *types.Transaction, chainID *big.Int) (*types.Transaction, error) {
+	if !w.session.verified {
+		if err := w.Open(passphrase); err != nil {
+			return nil, err
+		}
+	}
+	return w.SignTx(account, tx, chainID)
+}
+
+// findAccountPath returns the derivation path for the provided account.
+// It first checks for the address in the list of pinned accounts, and if it is
+// not found, attempts to parse the derivation path from the account's URL.
+func (w *Wallet) findAccountPath(account accounts.Account) (accounts.DerivationPath, error) {
+	pairing := w.Hub.getPairing(w)
+	if path, ok := pairing.Accounts[account.Address]; ok {
+		return path, nil
+	}
+
+	// Look for the path in the URL
+	if account.URL.Scheme != w.Hub.scheme {
+		return nil, fmt.Errorf("Scheme %s does not match wallet scheme %s", account.URL.Scheme, w.Hub.scheme)
+	}
+
+	parts := strings.SplitN(account.URL.Path, "/", 2)
+	if len(parts) != 2 {
+		return nil, fmt.Errorf("Invalid URL format: %s", account.URL)
+	}
+
+	if parts[0] != fmt.Sprintf("%x", w.PublicKey[1:3]) {
+		return nil, fmt.Errorf("URL %s is not for this wallet", account.URL)
+	}
+
+	return accounts.ParseDerivationPath(parts[1])
+}
+
+// Session represents a secured communication session with the wallet
+type Session struct {
+	Wallet   *Wallet               // A handle to the wallet that opened the session
+	Channel  *SecureChannelSession // A secure channel for encrypted messages
+	verified bool                  // Whether the pin has been verified in this session.
+}
+
+// pair establishes a new pairing over this channel, using the provided secret.
+func (s *Session) pair(secret []byte) (SmartcardPairing, error) {
+	err := s.Channel.Pair(secret)
+	if err != nil {
+		return SmartcardPairing{}, err
+	}
+
+	return SmartcardPairing{
+		PublicKey:    s.Wallet.PublicKey,
+		PairingIndex: s.Channel.PairingIndex,
+		PairingKey:   s.Channel.PairingKey,
+		Accounts:     make(map[common.Address]accounts.DerivationPath),
+	}, nil
+}
+
+// unpair deletes an existing pairing
+func (s *Session) unpair() error {
+	if !s.verified {
+		return fmt.Errorf("Unpair requires that the PIN be verified")
+	}
+	return s.Channel.Unpair()
+}
+
+// verifyPin unlocks a wallet with the provided pin
+func (s *Session) verifyPin(pin []byte) error {
+	if _, err := s.Channel.TransmitEncrypted(CLA_SCWALLET, INS_VERIFY_PIN, 0, 0, pin); err != nil {
+		return err
+	}
+	s.verified = true
+	return nil
+}
+
+// release releases resources associated with the channel
+func (s *Session) release() error {
+	return s.Wallet.card.Disconnect(scard.LeaveCard)
+}
+
+// paired returns true if a valid pairing exists
+func (s *Session) paired() bool {
+	return s.Channel.PairingKey != nil
+}
+
+// authenticate uses an existing pairing to establish a secure channel
+func (s *Session) authenticate(pairing SmartcardPairing) error {
+	if !bytes.Equal(s.Wallet.PublicKey, pairing.PublicKey) {
+		return fmt.Errorf("Cannot pair using another wallet's pairing; %x != %x", s.Wallet.PublicKey, pairing.PublicKey)
+	}
+	s.Channel.PairingKey = pairing.PairingKey
+	s.Channel.PairingIndex = pairing.PairingIndex
+	return s.Channel.Open()
+}
+
+// walletStatus describes a smartcard wallet's status information
+type walletStatus struct {
+	PinRetryCount        int  // Number of remaining PIN retries
+	PukRetryCount        int  // Number of remaining PUK retries
+	Initialized          bool // Whether the card has been initialized with a private key
+	SupportsPKDerivation bool // Whether the card supports doing public key derivation itself
+}
+
+func (w walletStatus) String() string {
+	return fmt.Sprintf("pinRetryCount=%d, pukRetryCount=%d, initialized=%t, supportsPkDerivation=%t", w.PinRetryCount, w.PukRetryCount, w.Initialized, w.SupportsPKDerivation)
+}
+
+// getWalletStatus fetches the wallet's status from the card
+func (s *Session) getWalletStatus() (*walletStatus, error) {
+	response, err := s.Channel.TransmitEncrypted(CLA_SCWALLET, INS_STATUS, STATUS_P1_WALLET_STATUS, 0, nil)
+	if err != nil {
+		return nil, err
+	}
+
+	status := new(walletStatus)
+	if _, err := asn1.UnmarshalWithParams(response.Data, status, "tag:3"); err != nil {
+		return nil, err
+	}
+
+	return status, nil
+}
+
+// getDerivationPath fetches the wallet's current derivation path from the card
+func (s *Session) getDerivationPath() (accounts.DerivationPath, error) {
+	response, err := s.Channel.TransmitEncrypted(CLA_SCWALLET, INS_STATUS, STATUS_P1_PATH, 0, nil)
+	if err != nil {
+		return nil, err
+	}
+
+	buf := bytes.NewReader(response.Data)
+	path := make(accounts.DerivationPath, len(response.Data)/4)
+	return path, binary.Read(buf, binary.BigEndian, &path)
+}
+
+// initializeData contains data needed to initialize the smartcard wallet
+type initializeData struct {
+	PublicKey  []byte `asn1:"tag:0"`
+	PrivateKey []byte `asn1:"tag:1"`
+	ChainCode  []byte `asn1:"tag:2"`
+}
+
+// initialize initializes the card with new key data
+func (s *Session) initialize(seed []byte) error {
+	// HMAC the seed to produce the private key and chain code
+	mac := hmac.New(sha512.New, []byte("Bitcoin seed"))
+	mac.Write(seed)
+	seed = mac.Sum(nil)
+
+	key, err := crypto.ToECDSA(seed[:32])
+	if err != nil {
+		return err
+	}
+
+	id := initializeData{}
+	id.PublicKey = crypto.FromECDSAPub(&key.PublicKey)
+	id.PrivateKey = seed[:32]
+	id.ChainCode = seed[32:]
+	data, err := asn1.Marshal(id)
+	if err != nil {
+		return err
+	}
+
+	// Nasty hack to force the top-level struct tag to be context-specific
+	data[0] = 0xA1
+
+	_, err = s.Channel.TransmitEncrypted(CLA_SCWALLET, INS_LOAD_KEY, 0x02, 0, data)
+	return err
+}
+
+// derive derives a new HD key path on the card
+func (s *Session) derive(path accounts.DerivationPath) (accounts.Account, error) {
+	// If the current path is a prefix of the desired path, we don't have to
+	// start again.
+	remainingPath := path
+
+	pubkey, err := s.getPublicKey()
+	if err != nil {
+		return accounts.Account{}, err
+	}
+	currentPath, err := s.getDerivationPath()
+	if err != nil {
+		return accounts.Account{}, err
+	}
+
+	reset := false
+	if len(currentPath) <= len(path) {
+		for i := 0; i < len(currentPath); i++ {
+			if path[i] != currentPath[i] {
+				reset = true
+				break
+			}
+		}
+		if !reset {
+			remainingPath = path[len(currentPath):]
+		}
+	} else {
+		reset = true
+	}
+
+	for _, pathComponent := range remainingPath {
+		pubkey, err = s.deriveKeyAssisted(reset, pathComponent)
+		reset = false
+		if err != nil {
+			return accounts.Account{}, err
+		}
+	}
+	return s.Wallet.makeAccount(crypto.PubkeyToAddress(*crypto.ToECDSAPub(pubkey)), path), nil
+}
+
+// keyDerivationInfo contains information on the current key derivation step
+type keyDerivationInfo struct {
+	PublicKeyX []byte `asn1:"tag:3"` // The X coordinate of the current public key
+	Signature  struct {
+		R *big.Int
+		S *big.Int
+	}
+}
+
+// deriveKeyAssisted does one step of assisted key generation, asking the card to generate
+// a specific path, and performing the necessary computations to finish the public key
+// generation step.
+func (s *Session) deriveKeyAssisted(reset bool, pathComponent uint32) ([]byte, error) {
+	p1 := DERIVE_P1_ASSISTED
+	if !reset {
+		p1 |= DERIVE_P1_APPEND
+	}
+
+	buf := new(bytes.Buffer)
+	if err := binary.Write(buf, binary.BigEndian, pathComponent); err != nil {
+		return nil, err
+	}
+	response, err := s.Channel.TransmitEncrypted(CLA_SCWALLET, INS_DERIVE_KEY, p1, DERIVE_P2_KEY_PATH, buf.Bytes())
+	if err != nil {
+		return nil, err
+	}
+
+	keyinfo := new(keyDerivationInfo)
+	if _, err := asn1.UnmarshalWithParams(response.Data, keyinfo, "tag:2"); err != nil {
+		return nil, err
+	}
+
+	rbytes, sbytes := keyinfo.Signature.R.Bytes(), keyinfo.Signature.S.Bytes()
+	sig := make([]byte, 65)
+	copy(sig[32-len(rbytes):32], rbytes)
+	copy(sig[64-len(sbytes):64], sbytes)
+
+	pubkey, err := determinePublicKey(sig, keyinfo.PublicKeyX)
+	if err != nil {
+		return nil, err
+	}
+
+	_, err = s.Channel.TransmitEncrypted(CLA_SCWALLET, INS_DERIVE_KEY, DERIVE_P1_ASSISTED|DERIVE_P1_APPEND, DERIVE_P2_PUBLIC_KEY, pubkey)
+	if err != nil {
+		return nil, err
+	}
+
+	return pubkey, nil
+}
+
+// keyExport contains information on an exported keypair
+type keyExport struct {
+	PublicKey  []byte `asn1:"tag:0"`
+	PrivateKey []byte `asn1:"tag:1,optional"`
+}
+
+// getPublicKey returns the public key for the current derivation path
+func (s *Session) getPublicKey() ([]byte, error) {
+	response, err := s.Channel.TransmitEncrypted(CLA_SCWALLET, INS_EXPORT_KEY, EXPORT_P1_ANY, EXPORT_P2_PUBKEY, nil)
+	if err != nil {
+		return nil, err
+	}
+
+	keys := new(keyExport)
+	if _, err := asn1.UnmarshalWithParams(response.Data, keys, "tag:1"); err != nil {
+		return nil, err
+	}
+
+	return keys.PublicKey, nil
+}
+
+// signatureData contains information on a signature - the signature itself and
+// the corresponding public key
+type signatureData struct {
+	PublicKey []byte `asn1:"tag:0"`
+	Signature struct {
+		R *big.Int
+		S *big.Int
+	}
+}
+
+// sign asks the card to sign a message, and returns a valid signature after
+// recovering the v value.
+func (s *Session) sign(path accounts.DerivationPath, hash []byte) ([]byte, error) {
+	startTime := time.Now()
+	_, err := s.derive(path)
+	if err != nil {
+		return nil, err
+	}
+	deriveTime := time.Now()
+
+	response, err := s.Channel.TransmitEncrypted(CLA_SCWALLET, INS_SIGN, SIGN_P1_PRECOMPUTED_HASH, SIGN_P2_ONLY_BLOCK, hash)
+	if err != nil {
+		return nil, err
+	}
+
+	sigdata := new(signatureData)
+	if _, err := asn1.UnmarshalWithParams(response.Data, sigdata, "tag:0"); err != nil {
+		return nil, err
+	}
+
+	// Serialize the signature
+	rbytes, sbytes := sigdata.Signature.R.Bytes(), sigdata.Signature.S.Bytes()
+	sig := make([]byte, 65)
+	copy(sig[32-len(rbytes):32], rbytes)
+	copy(sig[64-len(sbytes):64], sbytes)
+
+	// Recover the V value.
+	sig, err = makeRecoverableSignature(hash, sig, sigdata.PublicKey)
+	if err != nil {
+		return nil, err
+	}
+
+	log.Debug("Signed using smartcard", "deriveTime", deriveTime.Sub(startTime), "signingTime", time.Since(deriveTime))
+
+	return sig, nil
+}
+
+// determinePublicKey uses a signature and the X component of a public key to
+// recover the entire public key.
+func determinePublicKey(sig, pubkeyX []byte) ([]byte, error) {
+	for v := 0; v < 2; v++ {
+		sig[64] = byte(v)
+		pubkey, err := crypto.Ecrecover(DerivationSignatureHash[:], sig)
+		if err == nil {
+			if bytes.Compare(pubkey[1:33], pubkeyX) == 0 {
+				return pubkey, nil
+			}
+		} else if v == 1 || err != secp256k1.ErrRecoverFailed {
+			return nil, err
+		}
+	}
+	return nil, PubkeyMismatchError
+}
+
+// makeRecoverableSignature uses a signature and an expected public key to
+// recover the v value and produce a recoverable signature.
+func makeRecoverableSignature(hash, sig, expectedPubkey []byte) ([]byte, error) {
+	for v := 0; v < 2; v++ {
+		sig[64] = byte(v)
+		pubkey, err := crypto.Ecrecover(hash, sig)
+		if err == nil {
+			if bytes.Compare(pubkey, expectedPubkey) == 0 {
+				return sig, nil
+			}
+		} else if v == 1 || err != secp256k1.ErrRecoverFailed {
+			return nil, err
+		}
+	}
+	return nil, PubkeyMismatchError
+}

internal/ethapi/api.go

@@ -28,6 +28,7 @@ import (
 	"github.com/davecgh/go-spew/spew"
 	"github.com/ethereum/go-ethereum/accounts"
 	"github.com/ethereum/go-ethereum/accounts/keystore"
+	"github.com/ethereum/go-ethereum/accounts/scwallet"
 	"github.com/ethereum/go-ethereum/common"
 	"github.com/ethereum/go-ethereum/common/hexutil"
 	"github.com/ethereum/go-ethereum/common/math"
@@ -44,6 +45,7 @@ import (
 	"github.com/ethereum/go-ethereum/rlp"
 	"github.com/ethereum/go-ethereum/rpc"
 	"github.com/syndtr/goleveldb/leveldb"
+	"github.com/tyler-smith/go-bip39"
 )
 
 const (
@@ -471,6 +473,46 @@ func (s *PrivateAccountAPI) SignAndSendTransaction(ctx context.Context, args Sen
 	return s.SendTransaction(ctx, args, passwd)
 }
 
+func (s *PrivateAccountAPI) InitializeWallet(ctx context.Context, url string) (string, error) {
+	wallet, err := s.am.Wallet(url)
+	if err != nil {
+		return "", err
+	}
+
+	entropy, err := bip39.NewEntropy(256)
+	if err != nil {
+		return "", err
+	}
+
+	mnemonic, err := bip39.NewMnemonic(entropy)
+	if err != nil {
+		return "", err
+	}
+
+	seed := bip39.NewSeed(mnemonic, "")
+
+	switch wallet := wallet.(type) {
+	case *scwallet.Wallet:
+		return mnemonic, wallet.Initialize(seed)
+	default:
+		return "", fmt.Errorf("Specified wallet does not support initialization")
+	}
+}
+
+func (s *PrivateAccountAPI) Unpair(ctx context.Context, url string, pin string) error {
+	wallet, err := s.am.Wallet(url)
+	if err != nil {
+		return err
+	}
+
+	switch wallet := wallet.(type) {
+	case *scwallet.Wallet:
+		return wallet.Unpair([]byte(pin))
+	default:
+		return fmt.Errorf("Specified wallet does not support pairing")
+	}
+}
+
 // PublicBlockChainAPI provides an API to access the Ethereum blockchain.
 // It offers only methods that operate on public data that is freely available to anyone.
 type PublicBlockChainAPI struct {

internal/web3ext/web3ext.go

@@ -613,6 +613,16 @@ web3._extend({
 			params: 2,
 			inputFormatter: [web3._extend.formatters.inputTransactionFormatter, null]
 		}),
+		new web3._extend.Method({
+			name: 'unpair',
+			call: 'personal_unpair',
+			params: 2
+		}),
+		new web3._extend.Method({
+			name: 'initializeWallet',
+			call: 'personal_initializeWallet',
+			params: 1
+		})
 	],
 	properties: [
 		new web3._extend.Property({

node/config.go

@@ -29,6 +29,7 @@ import (
 	"github.com/ethereum/go-ethereum/accounts"
 	"github.com/ethereum/go-ethereum/accounts/external"
 	"github.com/ethereum/go-ethereum/accounts/keystore"
+	"github.com/ethereum/go-ethereum/accounts/scwallet"
 	"github.com/ethereum/go-ethereum/accounts/usbwallet"
 	"github.com/ethereum/go-ethereum/common"
 	"github.com/ethereum/go-ethereum/crypto"
@@ -504,6 +505,12 @@ func makeAccountManager(conf *Config) (*accounts.Manager, string, error) {
 				backends = append(backends, trezorhub)
 			}
 		}
+		// Start a smart card hub
+		if schub, err := scwallet.NewHub(scwallet.Scheme, keydir); err != nil {
+			log.Warn(fmt.Sprintf("Failed to start smart card hub, disabling: %v", err))
+		} else {
+			backends = append(backends, schub)
+		}
 	}
 
 	return accounts.NewManager(&accounts.Config{InsecureUnlockAllowed: conf.InsecureUnlockAllowed}, backends...), ephemeral, nil

vendor/github.com/ebfe/scard/LICENSE

+Copyright (c) 2016, Michael Gehring <mg@ebfe.org>
+All rights reserved.
+
+Redistribution and use in source and binary forms, with or without modification,
+are permitted provided that the following conditions are met:
+
+* Redistributions of source code must retain the above copyright notice, this
+  list of conditions and the following disclaimer.
+
+* Redistributions in binary form must reproduce the above copyright notice, this
+  list of conditions and the following disclaimer in the documentation and/or
+  other materials provided with the distribution.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
+ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR
+ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
+ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

vendor/github.com/ebfe/scard/README.md

+scard
+=====
+
+[![GoDoc](https://godoc.org/github.com/ebfe/scard?status.svg)](https://godoc.org/github.com/ebfe/scard)
+
+Go bindings to the PC/SC API.
+
+## Installation
+
+	go get github.com/ebfe/scard
+
+## Bugs
+
+	- Memory layouts/GC needs a thorough review.

vendor/github.com/ebfe/scard/scard.go

+// Package scard provides bindings to the PC/SC API.
+package scard
+
+import (
+	"time"
+	"unsafe"
+)
+
+type CardStatus struct {
+	Reader         string
+	State          State
+	ActiveProtocol Protocol
+	Atr            []byte
+}
+
+type ReaderState struct {
+	Reader       string
+	UserData     interface{}
+	CurrentState StateFlag
+	EventState   StateFlag
+	Atr          []byte
+}
+
+type Context struct {
+	ctx uintptr
+}
+
+type Card struct {
+	handle         uintptr
+	activeProtocol Protocol
+}
+
+// wraps SCardEstablishContext
+func EstablishContext() (*Context, error) {
+	ctx, r := scardEstablishContext(ScopeSystem, 0, 0)
+	if r != ErrSuccess {
+		return nil, r
+	}
+
+	return &Context{ctx: ctx}, nil
+}
+
+// wraps SCardIsValidContext
+func (ctx *Context) IsValid() (bool, error) {
+	r := scardIsValidContext(ctx.ctx)
+	switch r {
+	case ErrSuccess:
+		return true, nil
+	case ErrInvalidHandle:
+		return false, nil
+	default:
+		return false, r
+	}
+}
+
+// wraps SCardCancel
+func (ctx *Context) Cancel() error {
+	r := scardCancel(ctx.ctx)
+	if r != ErrSuccess {
+		return r
+	}
+	return nil
+}
+
+// wraps SCardReleaseContext
+func (ctx *Context) Release() error {
+	r := scardReleaseContext(ctx.ctx)
+	if r != ErrSuccess {
+		return r
+	}
+	return nil
+}
+
+// wraps SCardListReaders
+func (ctx *Context) ListReaders() ([]string, error) {
+	needed, r := scardListReaders(ctx.ctx, nil, nil, 0)
+	if r != ErrSuccess {
+		return nil, r
+	}
+
+	buf := make(strbuf, needed)
+	n, r := scardListReaders(ctx.ctx, nil, buf.ptr(), uint32(len(buf)))
+	if r != ErrSuccess {
+		return nil, r
+	}
+	return decodemstr(buf[:n]), nil
+}
+
+// wraps SCardListReaderGroups
+func (ctx *Context) ListReaderGroups() ([]string, error) {
+	needed, r := scardListReaderGroups(ctx.ctx, nil, 0)
+	if r != ErrSuccess {
+		return nil, r
+	}
+
+	buf := make(strbuf, needed)
+	n, r := scardListReaderGroups(ctx.ctx, buf.ptr(), uint32(len(buf)))
+	if r != ErrSuccess {
+		return nil, r
+	}
+	return decodemstr(buf[:n]), nil
+}
+
+// wraps SCardGetStatusChange
+func (ctx *Context) GetStatusChange(readerStates []ReaderState, timeout time.Duration) error {
+
+	dwTimeout := durationToTimeout(timeout)
+	states := make([]scardReaderState, len(readerStates))
+
+	for i := range readerStates {
+		var err error
+		states[i], err = readerStates[i].toSys()
+		if err != nil {
+			return err
+		}
+	}
+
+	r := scardGetStatusChange(ctx.ctx, dwTimeout, states)
+	if r != ErrSuccess {
+		return r
+	}
+
+	for i := range readerStates {
+		(&readerStates[i]).update(&states[i])
+	}
+
+	return nil
+}
+
+// wraps SCardConnect
+func (ctx *Context) Connect(reader string, mode ShareMode, proto Protocol) (*Card, error) {
+	creader, err := encodestr(reader)
+	if err != nil {
+		return nil, err
+	}
+	handle, activeProtocol, r := scardConnect(ctx.ctx, creader.ptr(), mode, proto)
+	if r != ErrSuccess {
+		return nil, r
+	}
+	return &Card{handle: handle, activeProtocol: activeProtocol}, nil
+}
+
+// wraps SCardDisconnect
+func (card *Card) Disconnect(d Disposition) error {
+	r := scardDisconnect(card.handle, d)
+	if r != ErrSuccess {
+		return r
+	}
+	return nil
+}
+
+// wraps SCardReconnect
+func (card *Card) Reconnect(mode ShareMode, proto Protocol, disp Disposition) error {
+	activeProtocol, r := scardReconnect(card.handle, mode, proto, disp)
+	if r != ErrSuccess {
+		return r
+	}
+	card.activeProtocol = activeProtocol
+	return nil
+}
+
+// wraps SCardBeginTransaction
+func (card *Card) BeginTransaction() error {
+	r := scardBeginTransaction(card.handle)
+	if r != ErrSuccess {
+		return r
+	}
+	return nil
+}
+
+// wraps SCardEndTransaction
+func (card *Card) EndTransaction(disp Disposition) error {
+	r := scardEndTransaction(card.handle, disp)
+	if r != ErrSuccess {
+		return r
+	}
+	return nil
+}
+
+// wraps SCardStatus
+func (card *Card) Status() (*CardStatus, error) {
+	reader, state, proto, atr, err := scardCardStatus(card.handle)
+	if err != ErrSuccess {
+		return nil, err
+	}
+	return &CardStatus{Reader: reader, State: state, ActiveProtocol: proto, Atr: atr}, nil
+}
+
+// wraps SCardTransmit
+func (card *Card) Transmit(cmd []byte) ([]byte, error) {
+	rsp := make([]byte, maxBufferSizeExtended)
+	rspLen, err := scardTransmit(card.handle, card.activeProtocol, cmd, rsp)
+	if err != ErrSuccess {
+		return nil, err
+	}
+	return rsp[:rspLen], nil
+}
+
+// wraps SCardControl
+func (card *Card) Control(ioctl uint32, in []byte) ([]byte, error) {
+	var out [0xffff]byte
+	outLen, err := scardControl(card.handle, ioctl, in, out[:])
+	if err != ErrSuccess {
+		return nil, err
+	}
+	return out[:outLen], nil
+}
+
+// wraps SCardGetAttrib
+func (card *Card) GetAttrib(id Attrib) ([]byte, error) {
+	needed, err := scardGetAttrib(card.handle, id, nil)
+	if err != ErrSuccess {
+		return nil, err
+	}
+
+	var attrib = make([]byte, needed)
+	n, err := scardGetAttrib(card.handle, id, attrib)
+	if err != ErrSuccess {
+		return nil, err
+	}
+	return attrib[:n], nil
+}
+
+// wraps SCardSetAttrib
+func (card *Card) SetAttrib(id Attrib, data []byte) error {
+	err := scardSetAttrib(card.handle, id, data)
+	if err != ErrSuccess {
+		return err
+	}
+	return nil
+}
+
+func durationToTimeout(timeout time.Duration) uint32 {
+	switch {
+	case timeout < 0:
+		return infiniteTimeout
+	case timeout > time.Duration(infiniteTimeout)*time.Millisecond:
+		return infiniteTimeout - 1
+	default:
+		return uint32(timeout / time.Millisecond)
+	}
+}
+
+func (buf strbuf) ptr() unsafe.Pointer {
+	return unsafe.Pointer(&buf[0])
+}
+
+func (buf strbuf) split() []strbuf {
+	var chunks []strbuf
+	for len(buf) > 0 && buf[0] != 0 {
+		i := 0
+		for i = range buf {
+			if buf[i] == 0 {
+				break
+			}
+		}
+		chunks = append(chunks, buf[:i+1])
+		buf = buf[i+1:]
+	}
+
+	return chunks
+}
+
+func encodemstr(strings ...string) (strbuf, error) {
+	var buf strbuf
+	for _, s := range strings {
+		utf16, err := encodestr(s)
+		if err != nil {
+			return nil, err
+		}
+		buf = append(buf, utf16...)
+	}
+	buf = append(buf, 0)
+	return buf, nil
+}
+
+func decodemstr(buf strbuf) []string {
+	var strings []string
+	for _, chunk := range buf.split() {
+		strings = append(strings, decodestr(chunk))
+	}
+	return strings
+}

vendor/github.com/ebfe/scard/scard_darwin.go

+// +build darwin
+
+package scard
+
+// #cgo LDFLAGS: -framework PCSC
+// #cgo CFLAGS: -I /usr/include
+// #include <stdlib.h>
+// #include <PCSC/winscard.h>
+// #include <PCSC/wintypes.h>
+import "C"
+
+import (
+	"unsafe"
+)
+
+func (e Error) Error() string {
+	return "scard: " + C.GoString(C.pcsc_stringify_error(C.int32_t(e)))
+}
+
+// Version returns the libpcsclite version string
+func Version() string {
+	return C.PCSCLITE_VERSION_NUMBER
+}
+
+func scardEstablishContext(scope Scope, reserved1, reserved2 uintptr) (uintptr, Error) {
+	var ctx C.SCARDCONTEXT
+	r := C.SCardEstablishContext(C.uint32_t(scope), unsafe.Pointer(reserved1), unsafe.Pointer(reserved2), &ctx)
+	return uintptr(ctx), Error(r)
+}
+
+func scardIsValidContext(ctx uintptr) Error {
+	r := C.SCardIsValidContext(C.SCARDCONTEXT(ctx))
+	return Error(r)
+}
+
+func scardCancel(ctx uintptr) Error {
+	r := C.SCardCancel(C.SCARDCONTEXT(ctx))
+	return Error(r)
+}
+
+func scardReleaseContext(ctx uintptr) Error {
+	r := C.SCardReleaseContext(C.SCARDCONTEXT(ctx))
+	return Error(r)
+}
+
+func scardListReaders(ctx uintptr, groups, buf unsafe.Pointer, bufLen uint32) (uint32, Error) {
+	dwBufLen := C.uint32_t(bufLen)
+	r := C.SCardListReaders(C.SCARDCONTEXT(ctx), (C.LPCSTR)(groups), (C.LPSTR)(buf), &dwBufLen)
+	return uint32(dwBufLen), Error(r)
+}
+
+func scardListReaderGroups(ctx uintptr, buf unsafe.Pointer, bufLen uint32) (uint32, Error) {
+	dwBufLen := C.uint32_t(bufLen)
+	r := C.SCardListReaderGroups(C.SCARDCONTEXT(ctx), (C.LPSTR)(buf), &dwBufLen)
+	return uint32(dwBufLen), Error(r)
+}
+
+func scardGetStatusChange(ctx uintptr, timeout uint32, states []scardReaderState) Error {
+	// In darwin, the LPSCARD_READERSTATE_A has 1 byte alignment and hence
+	// has no trailing padding. Go does add 3 bytes of padding (on both 32
+	// and 64 bits), so we pack an array manually instead.
+	const size = int(unsafe.Sizeof(states[0])) - 3
+	buf := make([]byte, size*len(states))
+	for i, _ := range states {
+		copy(buf[i*size:(i+1)*size], (*(*[size]byte)(unsafe.Pointer(&states[i])))[:])
+	}
+	r := C.SCardGetStatusChange(C.SCARDCONTEXT(ctx), C.uint32_t(timeout), (C.LPSCARD_READERSTATE_A)(unsafe.Pointer(&buf[0])), C.uint32_t(len(states)))
+	for i, _ := range states {
+		copy((*(*[size]byte)(unsafe.Pointer(&states[i])))[:], buf[i*size:(i+1)*size])
+	}
+	return Error(r)
+}
+
+func scardConnect(ctx uintptr, reader unsafe.Pointer, shareMode ShareMode, proto Protocol) (uintptr, Protocol, Error) {
+	var handle C.SCARDHANDLE
+	var activeProto C.uint32_t
+
+	r := C.SCardConnect(C.SCARDCONTEXT(ctx), C.LPCSTR(reader), C.uint32_t(shareMode), C.uint32_t(proto), &handle, &activeProto)
+
+	return uintptr(handle), Protocol(activeProto), Error(r)
+}
+
+func scardDisconnect(card uintptr, d Disposition) Error {
+	r := C.SCardDisconnect(C.SCARDHANDLE(card), C.uint32_t(d))
+	return Error(r)
+}
+
+func scardReconnect(card uintptr, mode ShareMode, proto Protocol, disp Disposition) (Protocol, Error) {
+	var activeProtocol C.uint32_t
+	r := C.SCardReconnect(C.SCARDHANDLE(card), C.uint32_t(mode), C.uint32_t(proto), C.uint32_t(disp), &activeProtocol)
+	return Protocol(activeProtocol), Error(r)
+}
+
+func scardBeginTransaction(card uintptr) Error {
+	r := C.SCardBeginTransaction(C.SCARDHANDLE(card))
+	return Error(r)
+}
+
+func scardEndTransaction(card uintptr, disp Disposition) Error {
+	r := C.SCardEndTransaction(C.SCARDHANDLE(card), C.uint32_t(disp))
+	return Error(r)
+}
+
+func scardCardStatus(card uintptr) (string, State, Protocol, []byte, Error) {
+	var readerBuf [C.MAX_READERNAME + 1]byte
+	var readerLen = C.uint32_t(len(readerBuf))
+	var state, proto C.uint32_t
+	var atr [maxAtrSize]byte
+	var atrLen = C.uint32_t(len(atr))
+
+	r := C.SCardStatus(C.SCARDHANDLE(card), (C.LPSTR)(unsafe.Pointer(&readerBuf[0])), &readerLen, &state, &proto, (*C.uchar)(&atr[0]), &atrLen)
+
+	return decodestr(readerBuf[:readerLen]), State(state), Protocol(proto), atr[:atrLen], Error(r)
+}
+
+func scardTransmit(card uintptr, proto Protocol, cmd []byte, rsp []byte) (uint32, Error) {
+	var sendpci C.SCARD_IO_REQUEST
+	var recvpci C.SCARD_IO_REQUEST
+	var rspLen = C.uint32_t(len(rsp))
+
+	switch proto {
+	case ProtocolT0, ProtocolT1:
+		sendpci.dwProtocol = C.uint32_t(proto)
+	default:
+		panic("unknown protocol")
+	}
+	sendpci.cbPciLength = C.sizeof_SCARD_IO_REQUEST
+
+	r := C.SCardTransmit(C.SCARDHANDLE(card), &sendpci, (*C.uchar)(&cmd[0]), C.uint32_t(len(cmd)), &recvpci, (*C.uchar)(&rsp[0]), &rspLen)
+
+	return uint32(rspLen), Error(r)
+}
+
+func scardControl(card uintptr, ioctl uint32, in, out []byte) (uint32, Error) {
+	var ptrIn unsafe.Pointer
+	var outLen = C.uint32_t(len(out))
+
+	if len(in) != 0 {
+		ptrIn = unsafe.Pointer(&in[0])
+	}
+
+	r := C.SCardControl(C.SCARDHANDLE(card), C.uint32_t(ioctl), ptrIn, C.uint32_t(len(in)), unsafe.Pointer(&out[0]), C.uint32_t(len(out)), &outLen)
+	return uint32(outLen), Error(r)
+}
+
+func scardGetAttrib(card uintptr, id Attrib, buf []byte) (uint32, Error) {
+	var ptr *C.uint8_t
+
+	if len(buf) != 0 {
+		ptr = (*C.uint8_t)(&buf[0])
+	}
+
+	bufLen := C.uint32_t(len(buf))
+	r := C.SCardGetAttrib(C.SCARDHANDLE(card), C.uint32_t(id), ptr, &bufLen)
+
+	return uint32(bufLen), Error(r)
+}
+
+func scardSetAttrib(card uintptr, id Attrib, buf []byte) Error {
+	r := C.SCardSetAttrib(C.SCARDHANDLE(card), C.uint32_t(id), ((*C.uint8_t)(&buf[0])), C.uint32_t(len(buf)))
+	return Error(r)
+}
+
+type strbuf []byte
+
+func encodestr(s string) (strbuf, error) {
+	buf := strbuf(s + "\x00")
+	return buf, nil
+}
+
+func decodestr(buf strbuf) string {
+	if len(buf) == 0 {
+		return ""
+	}
+
+	if buf[len(buf)-1] == 0 {
+		buf = buf[:len(buf)-1]
+	}
+
+	return string(buf)
+}
+
+type scardReaderState struct {
+	szReader       uintptr
+	pvUserData     uintptr
+	dwCurrentState uint32
+	dwEventState   uint32
+	cbAtr          uint32
+	rgbAtr         [33]byte
+}
+
+var pinned = map[string]*strbuf{}
+
+func (rs *ReaderState) toSys() (scardReaderState, error) {
+	var sys scardReaderState
+
+	creader, err := encodestr(rs.Reader)
+	if err != nil {
+		return scardReaderState{}, err
+	}
+	pinned[rs.Reader] = &creader
+	sys.szReader = uintptr(creader.ptr())
+	sys.dwCurrentState = uint32(rs.CurrentState)
+	sys.cbAtr = uint32(len(rs.Atr))
+	for i, v := range rs.Atr {
+		sys.rgbAtr[i] = byte(v)
+	}
+	return sys, nil
+}
+
+func (rs *ReaderState) update(sys *scardReaderState) {
+	rs.EventState = StateFlag(sys.dwEventState)
+	if sys.cbAtr > 0 {
+		rs.Atr = make([]byte, int(sys.cbAtr))
+		for i := 0; i < int(sys.cbAtr); i++ {
+			rs.Atr[i] = byte(sys.rgbAtr[i])
+		}
+	}
+}

vendor/github.com/ebfe/scard/scard_unix.go

+// +build !windows,!darwin
+
+package scard
+
+// #cgo pkg-config: libpcsclite
+// #include <stdlib.h>
+// #include <winscard.h>
+import "C"
+
+import (
+	"unsafe"
+)
+
+func (e Error) Error() string {
+	return "scard: " + C.GoString(C.pcsc_stringify_error(C.LONG(e)))
+}
+
+// Version returns the libpcsclite version string
+func Version() string {
+	return C.PCSCLITE_VERSION_NUMBER
+}
+
+func scardEstablishContext(scope Scope, reserved1, reserved2 uintptr) (uintptr, Error) {
+	var ctx C.SCARDCONTEXT
+	r := C.SCardEstablishContext(C.DWORD(scope), C.LPCVOID(reserved1), C.LPCVOID(reserved2), &ctx)
+	return uintptr(ctx), Error(r)
+}
+
+func scardIsValidContext(ctx uintptr) Error {
+	r := C.SCardIsValidContext(C.SCARDCONTEXT(ctx))
+	return Error(r)
+}
+
+func scardCancel(ctx uintptr) Error {
+	r := C.SCardCancel(C.SCARDCONTEXT(ctx))
+	return Error(r)
+}
+
+func scardReleaseContext(ctx uintptr) Error {
+	r := C.SCardReleaseContext(C.SCARDCONTEXT(ctx))
+	return Error(r)
+}
+
+func scardListReaders(ctx uintptr, groups, buf unsafe.Pointer, bufLen uint32) (uint32, Error) {
+	dwBufLen := C.DWORD(bufLen)
+	r := C.SCardListReaders(C.SCARDCONTEXT(ctx), (C.LPCSTR)(groups), (C.LPSTR)(buf), &dwBufLen)
+	return uint32(dwBufLen), Error(r)
+}
+
+func scardListReaderGroups(ctx uintptr, buf unsafe.Pointer, bufLen uint32) (uint32, Error) {
+	dwBufLen := C.DWORD(bufLen)
+	r := C.SCardListReaderGroups(C.SCARDCONTEXT(ctx), (C.LPSTR)(buf), &dwBufLen)
+	return uint32(dwBufLen), Error(r)
+}
+
+func scardGetStatusChange(ctx uintptr, timeout uint32, states []scardReaderState) Error {
+	r := C.SCardGetStatusChange(C.SCARDCONTEXT(ctx), C.DWORD(timeout), (C.LPSCARD_READERSTATE)(unsafe.Pointer(&states[0])), C.DWORD(len(states)))
+	return Error(r)
+}
+
+func scardConnect(ctx uintptr, reader unsafe.Pointer, shareMode ShareMode, proto Protocol) (uintptr, Protocol, Error) {
+	var handle C.SCARDHANDLE
+	var activeProto C.DWORD
+
+	r := C.SCardConnect(C.SCARDCONTEXT(ctx), C.LPCSTR(reader), C.DWORD(shareMode), C.DWORD(proto), &handle, &activeProto)
+
+	return uintptr(handle), Protocol(activeProto), Error(r)
+}
+
+func scardDisconnect(card uintptr, d Disposition) Error {
+	r := C.SCardDisconnect(C.SCARDHANDLE(card), C.DWORD(d))
+	return Error(r)
+}
+
+func scardReconnect(card uintptr, mode ShareMode, proto Protocol, disp Disposition) (Protocol, Error) {
+	var activeProtocol C.DWORD
+	r := C.SCardReconnect(C.SCARDHANDLE(card), C.DWORD(mode), C.DWORD(proto), C.DWORD(disp), &activeProtocol)
+	return Protocol(activeProtocol), Error(r)
+}
+
+func scardBeginTransaction(card uintptr) Error {
+	r := C.SCardBeginTransaction(C.SCARDHANDLE(card))
+	return Error(r)
+}
+
+func scardEndTransaction(card uintptr, disp Disposition) Error {
+	r := C.SCardEndTransaction(C.SCARDHANDLE(card), C.DWORD(disp))
+	return Error(r)
+}
+
+func scardCardStatus(card uintptr) (string, State, Protocol, []byte, Error) {
+	var readerBuf [C.MAX_READERNAME + 1]byte
+	var readerLen = C.DWORD(len(readerBuf))
+	var state, proto C.DWORD
+	var atr [maxAtrSize]byte
+	var atrLen = C.DWORD(len(atr))
+
+	r := C.SCardStatus(C.SCARDHANDLE(card), (C.LPSTR)(unsafe.Pointer(&readerBuf[0])), &readerLen, &state, &proto, (*C.BYTE)(&atr[0]), &atrLen)
+
+	return decodestr(readerBuf[:readerLen]), State(state), Protocol(proto), atr[:atrLen], Error(r)
+}
+
+func scardTransmit(card uintptr, proto Protocol, cmd []byte, rsp []byte) (uint32, Error) {
+	var sendpci C.SCARD_IO_REQUEST
+	var recvpci C.SCARD_IO_REQUEST
+	var rspLen = C.DWORD(len(rsp))
+
+	switch proto {
+	case ProtocolT0, ProtocolT1:
+		sendpci.dwProtocol = C.ulong(proto)
+	default:
+		panic("unknown protocol")
+	}
+	sendpci.cbPciLength = C.sizeof_SCARD_IO_REQUEST
+
+	r := C.SCardTransmit(C.SCARDHANDLE(card), &sendpci, (*C.BYTE)(&cmd[0]), C.DWORD(len(cmd)), &recvpci, (*C.BYTE)(&rsp[0]), &rspLen)
+
+	return uint32(rspLen), Error(r)
+}
+
+func scardControl(card uintptr, ioctl uint32, in, out []byte) (uint32, Error) {
+	var ptrIn C.LPCVOID
+	var outLen = C.DWORD(len(out))
+
+	if len(in) != 0 {
+		ptrIn = C.LPCVOID(unsafe.Pointer(&in[0]))
+	}
+
+	r := C.SCardControl(C.SCARDHANDLE(card), C.DWORD(ioctl), ptrIn, C.DWORD(len(in)), (C.LPVOID)(unsafe.Pointer(&out[0])), C.DWORD(len(out)), &outLen)
+	return uint32(outLen), Error(r)
+}
+
+func scardGetAttrib(card uintptr, id Attrib, buf []byte) (uint32, Error) {
+	var ptr C.LPBYTE
+
+	if len(buf) != 0 {
+		ptr = C.LPBYTE(unsafe.Pointer(&buf[0]))
+	}
+
+	bufLen := C.DWORD(len(buf))
+	r := C.SCardGetAttrib(C.SCARDHANDLE(card), C.DWORD(id), ptr, &bufLen)
+
+	return uint32(bufLen), Error(r)
+}
+
+func scardSetAttrib(card uintptr, id Attrib, buf []byte) Error {
+	r := C.SCardSetAttrib(C.SCARDHANDLE(card), C.DWORD(id), (*C.BYTE)(unsafe.Pointer(&buf[0])), C.DWORD(len(buf)))
+	return Error(r)
+}
+
+type strbuf []byte
+
+func encodestr(s string) (strbuf, error) {
+	buf := strbuf(s + "\x00")
+	return buf, nil
+}
+
+func decodestr(buf strbuf) string {
+	if len(buf) == 0 {
+		return ""
+	}
+
+	if buf[len(buf)-1] == 0 {
+		buf = buf[:len(buf)-1]
+	}
+
+	return string(buf)
+}
+
+type scardReaderState struct {
+	szReader       uintptr
+	pvUserData     uintptr
+	dwCurrentState uintptr
+	dwEventState   uintptr
+	cbAtr          uintptr
+	rgbAtr         [33]byte
+}
+
+var pinned = map[string]*strbuf{}
+
+func (rs *ReaderState) toSys() (scardReaderState, error) {
+	var sys scardReaderState
+
+	creader, err := encodestr(rs.Reader)
+	if err != nil {
+		return scardReaderState{}, err
+	}
+	pinned[rs.Reader] = &creader
+	sys.szReader = uintptr(creader.ptr())
+	sys.dwCurrentState = uintptr(rs.CurrentState)
+	sys.cbAtr = uintptr(len(rs.Atr))
+	for i, v := range rs.Atr {
+		sys.rgbAtr[i] = byte(v)
+	}
+	return sys, nil
+}
+
+func (rs *ReaderState) update(sys *scardReaderState) {
+	rs.EventState = StateFlag(sys.dwEventState)
+	if sys.cbAtr > 0 {
+		rs.Atr = make([]byte, int(sys.cbAtr))
+		for i := 0; i < int(sys.cbAtr); i++ {
+			rs.Atr[i] = byte(sys.rgbAtr[i])
+		}
+	}
+}

vendor/github.com/ebfe/scard/scard_windows.go

+package scard
+
+import (
+	"fmt"
+	"syscall"
+	"unsafe"
+)
+
+var (
+	modwinscard = syscall.NewLazyDLL("winscard.dll")
+
+	procEstablishContext = modwinscard.NewProc("SCardEstablishContext")
+	procReleaseContext   = modwinscard.NewProc("SCardReleaseContext")
+	procIsValidContext   = modwinscard.NewProc("SCardIsValidContext")
+	procCancel           = modwinscard.NewProc("SCardCancel")
+	procListReaders      = modwinscard.NewProc("SCardListReadersW")
+	procListReaderGroups = modwinscard.NewProc("SCardListReaderGroupsW")
+	procGetStatusChange  = modwinscard.NewProc("SCardGetStatusChangeW")
+	procConnect          = modwinscard.NewProc("SCardConnectW")
+	procDisconnect       = modwinscard.NewProc("SCardDisconnect")
+	procReconnect        = modwinscard.NewProc("SCardReconnect")
+	procBeginTransaction = modwinscard.NewProc("SCardBeginTransaction")
+	procEndTransaction   = modwinscard.NewProc("SCardEndTransaction")
+	procStatus           = modwinscard.NewProc("SCardStatusW")
+	procTransmit         = modwinscard.NewProc("SCardTransmit")
+	procControl          = modwinscard.NewProc("SCardControl")
+	procGetAttrib        = modwinscard.NewProc("SCardGetAttrib")
+	procSetAttrib        = modwinscard.NewProc("SCardSetAttrib")
+
+	dataT0Pci = modwinscard.NewProc("g_rgSCardT0Pci")
+	dataT1Pci = modwinscard.NewProc("g_rgSCardT1Pci")
+)
+
+var scardIoReqT0 uintptr
+var scardIoReqT1 uintptr
+
+func init() {
+	if err := dataT0Pci.Find(); err != nil {
+		panic(err)
+	}
+	scardIoReqT0 = dataT0Pci.Addr()
+	if err := dataT1Pci.Find(); err != nil {
+		panic(err)
+	}
+	scardIoReqT1 = dataT1Pci.Addr()
+}
+
+func (e Error) Error() string {
+	err := syscall.Errno(e)
+	return fmt.Sprintf("scard: error(%x): %s", uintptr(e), err.Error())
+}
+
+func scardEstablishContext(scope Scope, reserved1, reserved2 uintptr) (uintptr, Error) {
+	var ctx uintptr
+	r, _, _ := procEstablishContext.Call(uintptr(scope), reserved1, reserved2, uintptr(unsafe.Pointer(&ctx)))
+	return ctx, Error(r)
+}
+
+func scardIsValidContext(ctx uintptr) Error {
+	r, _, _ := procIsValidContext.Call(ctx)
+	return Error(r)
+}
+
+func scardCancel(ctx uintptr) Error {
+	r, _, _ := procCancel.Call(ctx)
+	return Error(r)
+}
+
+func scardReleaseContext(ctx uintptr) Error {
+	r, _, _ := procReleaseContext.Call(ctx)
+	return Error(r)
+}
+
+func scardListReaders(ctx uintptr, groups, buf unsafe.Pointer, bufLen uint32) (uint32, Error) {
+	dwBufLen := uint32(bufLen)
+	r, _, _ := procListReaders.Call(ctx, uintptr(groups), uintptr(buf), uintptr(unsafe.Pointer(&dwBufLen)))
+	return dwBufLen, Error(r)
+}
+
+func scardListReaderGroups(ctx uintptr, buf unsafe.Pointer, bufLen uint32) (uint32, Error) {
+	dwBufLen := uint32(bufLen)
+	r, _, _ := procListReaderGroups.Call(ctx, uintptr(buf), uintptr(unsafe.Pointer(&dwBufLen)))
+	return dwBufLen, Error(r)
+}
+
+func scardGetStatusChange(ctx uintptr, timeout uint32, states []scardReaderState) Error {
+	r, _, _ := procGetStatusChange.Call(ctx, uintptr(timeout), uintptr(unsafe.Pointer(&states[0])), uintptr(len(states)))
+	return Error(r)
+}
+
+func scardConnect(ctx uintptr, reader unsafe.Pointer, shareMode ShareMode, proto Protocol) (uintptr, Protocol, Error) {
+	var handle uintptr
+	var activeProto uint32
+
+	r, _, _ := procConnect.Call(ctx, uintptr(reader), uintptr(shareMode), uintptr(proto), uintptr(unsafe.Pointer(&handle)), uintptr(unsafe.Pointer(&activeProto)))
+
+	return handle, Protocol(activeProto), Error(r)
+}
+
+func scardDisconnect(card uintptr, d Disposition) Error {
+	r, _, _ := procDisconnect.Call(card, uintptr(d))
+	return Error(r)
+}
+
+func scardReconnect(card uintptr, mode ShareMode, proto Protocol, disp Disposition) (Protocol, Error) {
+	var activeProtocol uint32
+	r, _, _ := procReconnect.Call(card, uintptr(mode), uintptr(proto), uintptr(disp), uintptr(unsafe.Pointer(&activeProtocol)))
+	return Protocol(activeProtocol), Error(r)
+}
+
+func scardBeginTransaction(card uintptr) Error {
+	r, _, _ := procBeginTransaction.Call(card)
+	return Error(r)
+}
+
+func scardEndTransaction(card uintptr, disp Disposition) Error {
+	r, _, _ := procEndTransaction.Call(card, uintptr(disp))
+	return Error(r)
+}
+
+func scardCardStatus(card uintptr) (string, State, Protocol, []byte, Error) {
+	var state, proto uint32
+	var atr [maxAtrSize]byte
+	var atrLen = uint32(len(atr))
+
+	reader := make(strbuf, maxReadername+1)
+	readerLen := uint32(len(reader))
+
+	r, _, _ := procStatus.Call(card, uintptr(reader.ptr()), uintptr(unsafe.Pointer(&readerLen)), uintptr(unsafe.Pointer(&state)), uintptr(unsafe.Pointer(&proto)), uintptr(unsafe.Pointer(&atr[0])), uintptr(unsafe.Pointer(&atrLen)))
+
+	return decodestr(reader[:readerLen]), State(state), Protocol(proto), atr[:atrLen], Error(r)
+}
+
+func scardTransmit(card uintptr, proto Protocol, cmd []byte, rsp []byte) (uint32, Error) {
+	var sendpci uintptr
+	var rspLen = uint32(len(rsp))
+
+	switch proto {
+	case ProtocolT0:
+		sendpci = scardIoReqT0
+	case ProtocolT1:
+		sendpci = scardIoReqT1
+	default:
+		panic("unknown protocol")
+	}
+
+	r, _, _ := procTransmit.Call(card, sendpci, uintptr(unsafe.Pointer(&cmd[0])), uintptr(len(cmd)), uintptr(0), uintptr(unsafe.Pointer(&rsp[0])), uintptr(unsafe.Pointer(&rspLen)))
+
+	return rspLen, Error(r)
+}
+
+func scardControl(card uintptr, ioctl uint32, in, out []byte) (uint32, Error) {
+	var ptrIn uintptr
+	var outLen = uint32(len(out))
+
+	if len(in) != 0 {
+		ptrIn = uintptr(unsafe.Pointer(&in[0]))
+	}
+
+	r, _, _ := procControl.Call(card, uintptr(ioctl), ptrIn, uintptr(len(in)), uintptr(unsafe.Pointer(&out[0])), uintptr(len(out)), uintptr(unsafe.Pointer(&outLen)))
+	return outLen, Error(r)
+}
+
+func scardGetAttrib(card uintptr, id Attrib, buf []byte) (uint32, Error) {
+	var ptr uintptr
+
+	if len(buf) != 0 {
+		ptr = uintptr(unsafe.Pointer(&buf[0]))
+	}
+
+	bufLen := uint32(len(buf))
+	r, _, _ := procGetAttrib.Call(card, uintptr(id), ptr, uintptr(unsafe.Pointer(&bufLen)))
+
+	return bufLen, Error(r)
+}
+
+func scardSetAttrib(card uintptr, id Attrib, buf []byte) Error {
+	r, _, _ := procSetAttrib.Call(card, uintptr(id), uintptr(unsafe.Pointer(&buf[0])), uintptr(len(buf)))
+	return Error(r)
+}
+
+type scardReaderState struct {
+	szReader       uintptr
+	pvUserData     uintptr
+	dwCurrentState uint32
+	dwEventState   uint32
+	cbAtr          uint32
+	rgbAtr         [36]byte
+}
+
+func (rs *ReaderState) toSys() (scardReaderState, error) {
+	var sys scardReaderState
+	creader, err := encodestr(rs.Reader)
+	if err != nil {
+		return scardReaderState{}, err
+	}
+	sys.szReader = uintptr(creader.ptr())
+	sys.dwCurrentState = uint32(rs.CurrentState)
+	sys.cbAtr = uint32(len(rs.Atr))
+	copy(sys.rgbAtr[:], rs.Atr)
+	return sys, nil
+}
+
+func (rs *ReaderState) update(sys *scardReaderState) {
+	rs.EventState = StateFlag(sys.dwEventState)
+	if sys.cbAtr > 0 {
+		rs.Atr = make([]byte, int(sys.cbAtr))
+		copy(rs.Atr, sys.rgbAtr[:])
+	}
+}
+
+type strbuf []uint16
+
+func encodestr(s string) (strbuf, error) {
+	utf16, err := syscall.UTF16FromString(s)
+	return strbuf(utf16), err
+}
+
+func decodestr(buf strbuf) string {
+	return syscall.UTF16ToString(buf)
+}

vendor/github.com/ebfe/scard/zconst.go

+// Created by cgo -godefs - DO NOT EDIT
+// cgo -godefs -- -I /usr/include/PCSC/ const.go
+
+package scard
+
+type Attrib uint32
+
+const (
+	AttrVendorName           Attrib = 0x10100
+	AttrVendorIfdType        Attrib = 0x10101
+	AttrVendorIfdVersion     Attrib = 0x10102
+	AttrVendorIfdSerialNo    Attrib = 0x10103
+	AttrChannelId            Attrib = 0x20110
+	AttrAsyncProtocolTypes   Attrib = 0x30120
+	AttrDefaultClk           Attrib = 0x30121
+	AttrMaxClk               Attrib = 0x30122
+	AttrDefaultDataRate      Attrib = 0x30123
+	AttrMaxDataRate          Attrib = 0x30124
+	AttrMaxIfsd              Attrib = 0x30125
+	AttrSyncProtocolTypes    Attrib = 0x30126
+	AttrPowerMgmtSupport     Attrib = 0x40131
+	AttrUserToCardAuthDevice Attrib = 0x50140
+	AttrUserAuthInputDevice  Attrib = 0x50142
+	AttrCharacteristics      Attrib = 0x60150
+	AttrCurrentProtocolType  Attrib = 0x80201
+	AttrCurrentClk           Attrib = 0x80202
+	AttrCurrentF             Attrib = 0x80203
+	AttrCurrentD             Attrib = 0x80204
+	AttrCurrentN             Attrib = 0x80205
+	AttrCurrentW             Attrib = 0x80206
+	AttrCurrentIfsc          Attrib = 0x80207
+	AttrCurrentIfsd          Attrib = 0x80208
+	AttrCurrentBwt           Attrib = 0x80209
+	AttrCurrentCwt           Attrib = 0x8020a
+	AttrCurrentEbcEncoding   Attrib = 0x8020b
+	AttrExtendedBwt          Attrib = 0x8020c
+	AttrIccPresence          Attrib = 0x90300
+	AttrIccInterfaceStatus   Attrib = 0x90301
+	AttrCurrentIoState       Attrib = 0x90302
+	AttrAtrString            Attrib = 0x90303
+	AttrIccTypePerAtr        Attrib = 0x90304
+	AttrEscReset             Attrib = 0x7a000
+	AttrEscCancel            Attrib = 0x7a003
+	AttrEscAuthrequest       Attrib = 0x7a005
+	AttrMaxinput             Attrib = 0x7a007
+	AttrDeviceUnit           Attrib = 0x7fff0001
+	AttrDeviceInUse          Attrib = 0x7fff0002
+	AttrDeviceFriendlyName   Attrib = 0x7fff0003
+	AttrDeviceSystemName     Attrib = 0x7fff0004
+	AttrSupressT1IfsRequest  Attrib = 0x7fff0007
+)
+
+type Error uint32
+
+const (
+	ErrSuccess                Error = 0x0
+	ErrInternalError          Error = 0x80100001
+	ErrCancelled              Error = 0x80100002
+	ErrInvalidHandle          Error = 0x80100003
+	ErrInvalidParameter       Error = 0x80100004
+	ErrInvalidTarget          Error = 0x80100005
+	ErrNoMemory               Error = 0x80100006
+	ErrWaitedTooLong          Error = 0x80100007
+	ErrInsufficientBuffer     Error = 0x80100008
+	ErrUnknownReader          Error = 0x80100009
+	ErrTimeout                Error = 0x8010000a
+	ErrSharingViolation       Error = 0x8010000b
+	ErrNoSmartcard            Error = 0x8010000c
+	ErrUnknownCard            Error = 0x8010000d
+	ErrCantDispose            Error = 0x8010000e
+	ErrProtoMismatch          Error = 0x8010000f
+	ErrNotReady               Error = 0x80100010
+	ErrInvalidValue           Error = 0x80100011
+	ErrSystemCancelled        Error = 0x80100012
+	ErrCommError              Error = 0x80100013
+	ErrUnknownError           Error = 0x80100014
+	ErrInvalidAtr             Error = 0x80100015
+	ErrNotTransacted          Error = 0x80100016
+	ErrReaderUnavailable      Error = 0x80100017
+	ErrShutdown               Error = 0x80100018
+	ErrPciTooSmall            Error = 0x80100019
+	ErrReaderUnsupported      Error = 0x8010001a
+	ErrDuplicateReader        Error = 0x8010001b
+	ErrCardUnsupported        Error = 0x8010001c
+	ErrNoService              Error = 0x8010001d
+	ErrServiceStopped         Error = 0x8010001e
+	ErrUnexpected             Error = 0x8010001f
+	ErrUnsupportedFeature     Error = 0x8010001f
+	ErrIccInstallation        Error = 0x80100020
+	ErrIccCreateorder         Error = 0x80100021
+	ErrFileNotFound           Error = 0x80100024
+	ErrNoDir                  Error = 0x80100025
+	ErrNoFile                 Error = 0x80100026
+	ErrNoAccess               Error = 0x80100027
+	ErrWriteTooMany           Error = 0x80100028
+	ErrBadSeek                Error = 0x80100029
+	ErrInvalidChv             Error = 0x8010002a
+	ErrUnknownResMng          Error = 0x8010002b
+	ErrNoSuchCertificate      Error = 0x8010002c
+	ErrCertificateUnavailable Error = 0x8010002d
+	ErrNoReadersAvailable     Error = 0x8010002e
+	ErrCommDataLost           Error = 0x8010002f
+	ErrNoKeyContainer         Error = 0x80100030
+	ErrServerTooBusy          Error = 0x80100031
+	ErrUnsupportedCard        Error = 0x80100065
+	ErrUnresponsiveCard       Error = 0x80100066
+	ErrUnpoweredCard          Error = 0x80100067
+	ErrResetCard              Error = 0x80100068
+	ErrRemovedCard            Error = 0x80100069
+	ErrSecurityViolation      Error = 0x8010006a
+	ErrWrongChv               Error = 0x8010006b
+	ErrChvBlocked             Error = 0x8010006c
+	ErrEof                    Error = 0x8010006d
+	ErrCancelledByUser        Error = 0x8010006e
+	ErrCardNotAuthenticated   Error = 0x8010006f
+)
+
+type Protocol uint32
+
+const (
+	ProtocolUndefined Protocol = 0x0
+	ProtocolT0        Protocol = 0x1
+	ProtocolT1        Protocol = 0x2
+	ProtocolAny       Protocol = ProtocolT0 | ProtocolT1
+)
+
+type ShareMode uint32
+
+const (
+	ShareExclusive ShareMode = 0x1
+	ShareShared    ShareMode = 0x2
+	ShareDirect    ShareMode = 0x3
+)
+
+type Disposition uint32
+
+const (
+	LeaveCard   Disposition = 0x0
+	ResetCard   Disposition = 0x1
+	UnpowerCard Disposition = 0x2
+	EjectCard   Disposition = 0x3
+)
+
+type Scope uint32
+
+const (
+	ScopeUser     Scope = 0x0
+	ScopeTerminal Scope = 0x1
+	ScopeSystem   Scope = 0x2
+)
+
+type State uint32
+
+const (
+	Unknown    State = 0x1
+	Absent     State = 0x2
+	Present    State = 0x4
+	Swallowed  State = 0x8
+	Powered    State = 0x10
+	Negotiable State = 0x20
+	Specific   State = 0x40
+)
+
+type StateFlag uint32
+
+const (
+	StateUnaware     StateFlag = 0x0
+	StateIgnore      StateFlag = 0x1
+	StateChanged     StateFlag = 0x2
+	StateUnknown     StateFlag = 0x4
+	StateUnavailable StateFlag = 0x8
+	StateEmpty       StateFlag = 0x10
+	StatePresent     StateFlag = 0x20
+	StateAtrmatch    StateFlag = 0x40
+	StateExclusive   StateFlag = 0x80
+	StateInuse       StateFlag = 0x100
+	StateMute        StateFlag = 0x200
+	StateUnpowered   StateFlag = 0x400
+)
+
+const (
+	maxBufferSize         = 0x108
+	maxBufferSizeExtended = 0x1000c
+	maxReadername         = 0x80
+	maxAtrSize            = 0x21
+)
+
+const (
+	infiniteTimeout = 0xffffffff
+)

vendor/github.com/tyler-smith/go-bip39/LICENSE

+The MIT License (MIT)
+
+Copyright (c) 2014 Tyler Smith
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.

vendor/github.com/tyler-smith/go-bip39/README.md

+# go-bip39
+
+A golang implementation of the BIP0039 spec for mnemonic seeds
+
+
+## Credits
+
+English wordlist and test vectors are from the standard Python BIP0039 implementation
+from the Trezor guys: [https://github.com/trezor/python-mnemonic](https://github.com/trezor/python-mnemonic)
+
+## Example
+
+```go
+package main
+
+import (
+  "github.com/tyler-smith/go-bip39"
+  "github.com/tyler-smith/go-bip32"
+  "fmt"
+)
+
+func main(){
+  // Generate a mnemonic for memorization or user-friendly seeds
+  entropy, _ := bip39.NewEntropy(256)
+  mnemonic, _ := bip39.NewMnemonic(entropy)
+
+  // Generate a Bip32 HD wallet for the mnemonic and a user supplied password
+  seed := bip39.NewSeed(mnemonic, "Secret Passphrase")
+
+  masterKey, _ := bip32.NewMasterKey(seed)
+  publicKey := masterKey.PublicKey()
+
+  // Display mnemonic and keys
+  fmt.Println("Mnemonic: ", mnemonic)
+  fmt.Println("Master private key: ", masterKey)
+  fmt.Println("Master public key: ", publicKey)
+}
+```

vendor/github.com/tyler-smith/go-bip39/bip39.go

+package bip39
+
+import (
+	"crypto/rand"
+	"crypto/sha256"
+	"crypto/sha512"
+	"encoding/binary"
+	"errors"
+	"fmt"
+	"math/big"
+	"strings"
+
+	"golang.org/x/crypto/pbkdf2"
+)
+
+// Some bitwise operands for working with big.Ints
+var (
+	Last11BitsMask          = big.NewInt(2047)
+	RightShift11BitsDivider = big.NewInt(2048)
+	BigOne                  = big.NewInt(1)
+	BigTwo                  = big.NewInt(2)
+)
+
+// NewEntropy will create random entropy bytes
+// so long as the requested size bitSize is an appropriate size.
+func NewEntropy(bitSize int) ([]byte, error) {
+	err := validateEntropyBitSize(bitSize)
+	if err != nil {
+		return nil, err
+	}
+
+	entropy := make([]byte, bitSize/8)
+	_, err = rand.Read(entropy)
+	return entropy, err
+}
+
+// NewMnemonic will return a string consisting of the mnemonic words for
+// the given entropy.
+// If the provide entropy is invalid, an error will be returned.
+func NewMnemonic(entropy []byte) (string, error) {
+	// Compute some lengths for convenience
+	entropyBitLength := len(entropy) * 8
+	checksumBitLength := entropyBitLength / 32
+	sentenceLength := (entropyBitLength + checksumBitLength) / 11
+
+	err := validateEntropyBitSize(entropyBitLength)
+	if err != nil {
+		return "", err
+	}
+
+	// Add checksum to entropy
+	entropy = addChecksum(entropy)
+
+	// Break entropy up into sentenceLength chunks of 11 bits
+	// For each word AND mask the rightmost 11 bits and find the word at that index
+	// Then bitshift entropy 11 bits right and repeat
+	// Add to the last empty slot so we can work with LSBs instead of MSB
+
+	// Entropy as an int so we can bitmask without worrying about bytes slices
+	entropyInt := new(big.Int).SetBytes(entropy)
+
+	// Slice to hold words in
+	words := make([]string, sentenceLength)
+
+	// Throw away big int for AND masking
+	word := big.NewInt(0)
+
+	for i := sentenceLength - 1; i >= 0; i-- {
+		// Get 11 right most bits and bitshift 11 to the right for next time
+		word.And(entropyInt, Last11BitsMask)
+		entropyInt.Div(entropyInt, RightShift11BitsDivider)
+
+		// Get the bytes representing the 11 bits as a 2 byte slice
+		wordBytes := padByteSlice(word.Bytes(), 2)
+
+		// Convert bytes to an index and add that word to the list
+		words[i] = WordList[binary.BigEndian.Uint16(wordBytes)]
+	}
+
+	return strings.Join(words, " "), nil
+}
+
+// MnemonicToByteArray takes a mnemonic string and turns it into a byte array
+// suitable for creating another mnemonic.
+// An error is returned if the mnemonic is invalid.
+// FIXME
+// This does not work for all values in
+// the test vectors.  Namely
+// Vectors 0, 4, and 8.
+// This is not really important because BIP39 doesnt really define a conversion
+// from string to bytes.
+func MnemonicToByteArray(mnemonic string) ([]byte, error) {
+	if IsMnemonicValid(mnemonic) == false {
+		return nil, fmt.Errorf("Invalid mnemonic")
+	}
+	mnemonicSlice := strings.Split(mnemonic, " ")
+
+	bitSize := len(mnemonicSlice) * 11
+	err := validateEntropyWithChecksumBitSize(bitSize)
+	if err != nil {
+		return nil, err
+	}
+	checksumSize := bitSize % 32
+
+	b := big.NewInt(0)
+	modulo := big.NewInt(2048)
+	for _, v := range mnemonicSlice {
+		index, found := ReverseWordMap[v]
+		if found == false {
+			return nil, fmt.Errorf("Word `%v` not found in reverse map", v)
+		}
+		add := big.NewInt(int64(index))
+		b = b.Mul(b, modulo)
+		b = b.Add(b, add)
+	}
+	hex := b.Bytes()
+	checksumModulo := big.NewInt(0).Exp(big.NewInt(2), big.NewInt(int64(checksumSize)), nil)
+	entropy, _ := big.NewInt(0).DivMod(b, checksumModulo, big.NewInt(0))
+
+	entropyHex := entropy.Bytes()
+
+	byteSize := bitSize/8 + 1
+	if len(hex) != byteSize {
+		tmp := make([]byte, byteSize)
+		diff := byteSize - len(hex)
+		for i := 0; i < len(hex); i++ {
+			tmp[i+diff] = hex[i]
+		}
+		hex = tmp
+	}
+
+	validationHex := addChecksum(entropyHex)
+	if len(validationHex) != byteSize {
+		tmp2 := make([]byte, byteSize)
+		diff2 := byteSize - len(validationHex)
+		for i := 0; i < len(validationHex); i++ {
+			tmp2[i+diff2] = validationHex[i]
+		}
+		validationHex = tmp2
+	}
+
+	if len(hex) != len(validationHex) {
+		panic("[]byte len mismatch - it shouldn't happen")
+	}
+	for i := range validationHex {
+		if hex[i] != validationHex[i] {
+			return nil, fmt.Errorf("Invalid byte at position %v", i)
+		}
+	}
+	return hex, nil
+}
+
+// NewSeedWithErrorChecking creates a hashed seed output given the mnemonic string and a password.
+// An error is returned if the mnemonic is not convertible to a byte array.
+func NewSeedWithErrorChecking(mnemonic string, password string) ([]byte, error) {
+	_, err := MnemonicToByteArray(mnemonic)
+	if err != nil {
+		return nil, err
+	}
+	return NewSeed(mnemonic, password), nil
+}
+
+// NewSeed creates a hashed seed output given a provided string and password.
+// No checking is performed to validate that the string provided is a valid mnemonic.
+func NewSeed(mnemonic string, password string) []byte {
+	return pbkdf2.Key([]byte(mnemonic), []byte("mnemonic"+password), 2048, 64, sha512.New)
+}
+
+// Appends to data the first (len(data) / 32)bits of the result of sha256(data)
+// Currently only supports data up to 32 bytes
+func addChecksum(data []byte) []byte {
+	// Get first byte of sha256
+	hasher := sha256.New()
+	hasher.Write(data)
+	hash := hasher.Sum(nil)
+	firstChecksumByte := hash[0]
+
+	// len() is in bytes so we divide by 4
+	checksumBitLength := uint(len(data) / 4)
+
+	// For each bit of check sum we want we shift the data one the left
+	// and then set the (new) right most bit equal to checksum bit at that index
+	// staring from the left
+	dataBigInt := new(big.Int).SetBytes(data)
+	for i := uint(0); i < checksumBitLength; i++ {
+		// Bitshift 1 left
+		dataBigInt.Mul(dataBigInt, BigTwo)
+
+		// Set rightmost bit if leftmost checksum bit is set
+		if uint8(firstChecksumByte&(1<<(7-i))) > 0 {
+			dataBigInt.Or(dataBigInt, BigOne)
+		}
+	}
+
+	return dataBigInt.Bytes()
+}
+
+func padByteSlice(slice []byte, length int) []byte {
+	newSlice := make([]byte, length-len(slice))
+	return append(newSlice, slice...)
+}
+
+func validateEntropyBitSize(bitSize int) error {
+	if (bitSize%32) != 0 || bitSize < 128 || bitSize > 256 {
+		return errors.New("Entropy length must be [128, 256] and a multiple of 32")
+	}
+	return nil
+}
+
+func validateEntropyWithChecksumBitSize(bitSize int) error {
+	if (bitSize != 128+4) && (bitSize != 160+5) && (bitSize != 192+6) && (bitSize != 224+7) && (bitSize != 256+8) {
+		return fmt.Errorf("Wrong entropy + checksum size - expected %v, got %v", int((bitSize-bitSize%32)+(bitSize-bitSize%32)/32), bitSize)
+	}
+	return nil
+}
+
+// IsMnemonicValid attempts to verify that the provided mnemonic is valid.
+// Validity is determined by both the number of words being appropriate,
+// and that all the words in the mnemonic are present in the word list.
+func IsMnemonicValid(mnemonic string) bool {
+	// Create a list of all the words in the mnemonic sentence
+	words := strings.Fields(mnemonic)
+
+	//Get num of words
+	numOfWords := len(words)
+
+	// The number of words should be 12, 15, 18, 21 or 24
+	if numOfWords%3 != 0 || numOfWords < 12 || numOfWords > 24 {
+		return false
+	}
+
+	// Check if all words belong in the wordlist
+	for i := 0; i < numOfWords; i++ {
+		if !contains(WordList, words[i]) {
+			return false
+		}
+	}
+
+	return true
+}
+
+func contains(s []string, e string) bool {
+	for _, a := range s {
+		if a == e {
+			return true
+		}
+	}
+	return false
+}

vendor/github.com/tyler-smith/go-bip39/coverage.txt

+
+github.com/CrowBits/go-bip39/bip39.go	 addChecksum				 100.00% (11/11)
+github.com/CrowBits/go-bip39/bip39.go	 IsMnemonicValid			 100.00% (8/8)
+github.com/CrowBits/go-bip39/bip39.go	 NewEntropy				 100.00% (6/6)
+github.com/CrowBits/go-bip39/bip39.go	 contains				 100.00% (4/4)
+github.com/CrowBits/go-bip39/bip39.go	 NewSeedWithErrorChecking		 100.00% (4/4)
+github.com/CrowBits/go-bip39/bip39.go	 validateEntropyBitSize			 100.00% (3/3)
+github.com/CrowBits/go-bip39/bip39.go	 validateEntropyWithChecksumBitSize	 100.00% (3/3)
+github.com/CrowBits/go-bip39/bip39.go	 padByteSlice				 100.00% (2/2)
+github.com/CrowBits/go-bip39/wordlist.go init					 100.00% (2/2)
+github.com/CrowBits/go-bip39/bip39.go	 NewSeed				 100.00% (1/1)
+github.com/CrowBits/go-bip39/bip39.go	 NewMnemonic				 93.75% (15/16)
+github.com/CrowBits/go-bip39/bip39.go	 MnemonicToByteArray			 90.24% (37/41)
+github.com/CrowBits/go-bip39		 ----------------------------------	 95.05% (96/101)
+

vendor/github.com/tyler-smith/go-bip39/wordlist.go

+package bip39
+
+import (
+	"strings"
+)
+
+// The wordlist to use
+var WordList = EnglishWordList
+
+var ReverseWordMap map[string]int = map[string]int{}
+
+func init() {
+	for i, v := range WordList {
+		ReverseWordMap[v] = i
+	}
+}
+
+// Language-specific wordlists
+var EnglishWordList = strings.Split(englishWordList, "\n")
+var englishWordList = `abandon
+ability
+able
+about
+above
+absent
+absorb
+abstract
+absurd
+abuse
+access
+accident
+account
+accuse
+achieve
+acid
+acoustic
+acquire
+across
+act
+action
+actor
+actress
+actual
+adapt
+add
+addict
+address
+adjust
+admit
+adult
+advance
+advice
+aerobic
+affair
+afford
+afraid
+again
+age
+agent
+agree
+ahead
+aim
+air
+airport
+aisle
+alarm
+album
+alcohol
+alert
+alien
+all
+alley
+allow
+almost
+alone
+alpha
+already
+also
+alter
+always
+amateur
+amazing
+among
+amount
+amused
+analyst
+anchor
+ancient
+anger
+angle
+angry
+animal
+ankle
+announce
+annual
+another
+answer
+antenna
+antique
+anxiety
+any
+apart
+apology
+appear
+apple
+approve
+april
+arch
+arctic
+area
+arena
+argue
+arm
+armed
+armor
+army
+around
+arrange
+arrest
+arrive
+arrow
+art
+artefact
+artist
+artwork
+ask
+aspect
+assault
+asset
+assist
+assume
+asthma
+athlete
+atom
+attack
+attend
+attitude
+attract
+auction
+audit
+august
+aunt
+author
+auto
+autumn
+average
+avocado
+avoid
+awake
+aware
+away
+awesome
+awful
+awkward
+axis
+baby
+bachelor
+bacon
+badge
+bag
+balance
+balcony
+ball
+bamboo
+banana
+banner
+bar
+barely
+bargain
+barrel
+base
+basic
+basket
+battle
+beach
+bean
+beauty
+because
+become
+beef
+before
+begin
+behave
+behind
+believe
+below
+belt
+bench
+benefit
+best
+betray
+better
+between
+beyond
+bicycle
+bid
+bike
+bind
+biology
+bird
+birth
+bitter
+black
+blade
+blame
+blanket
+blast
+bleak
+bless
+blind
+blood
+blossom
+blouse
+blue
+blur
+blush
+board
+boat
+body
+boil
+bomb
+bone
+bonus
+book
+boost
+border
+boring
+borrow
+boss
+bottom
+bounce
+box
+boy
+bracket
+brain
+brand
+brass
+brave
+bread
+breeze
+brick
+bridge
+brief
+bright
+bring
+brisk
+broccoli
+broken
+bronze
+broom
+brother
+brown
+brush
+bubble
+buddy
+budget
+buffalo
+build
+bulb
+bulk
+bullet
+bundle
+bunker
+burden
+burger
+burst
+bus
+business
+busy
+butter
+buyer
+buzz
+cabbage
+cabin
+cable
+cactus
+cage
+cake
+call
+calm
+camera
+camp
+can
+canal
+cancel
+candy
+cannon
+canoe
+canvas
+canyon
+capable
+capital
+captain
+car
+carbon
+card
+cargo
+carpet
+carry
+cart
+case
+cash
+casino
+castle
+casual
+cat
+catalog
+catch
+category
+cattle
+caught
+cause
+caution
+cave
+ceiling
+celery
+cement
+census
+century
+cereal
+certain
+chair
+chalk
+champion
+change
+chaos
+chapter
+charge
+chase
+chat
+cheap
+check
+cheese
+chef
+cherry
+chest
+chicken
+chief
+child
+chimney
+choice
+choose
+chronic
+chuckle
+chunk
+churn
+cigar
+cinnamon
+circle
+citizen
+city
+civil
+claim
+clap
+clarify
+claw
+clay
+clean
+clerk
+clever
+click
+client
+cliff
+climb
+clinic
+clip
+clock
+clog
+close
+cloth
+cloud
+clown
+club
+clump
+cluster
+clutch
+coach
+coast
+coconut
+code
+coffee
+coil
+coin
+collect
+color
+column
+combine
+come
+comfort
+comic
+common
+company
+concert
+conduct
+confirm
+congress
+connect
+consider
+control
+convince
+cook
+cool
+copper
+copy
+coral
+core
+corn
+correct
+cost
+cotton
+couch
+country
+couple
+course
+cousin
+cover
+coyote
+crack
+cradle
+craft
+cram
+crane
+crash
+crater
+crawl
+crazy
+cream
+credit
+creek
+crew
+cricket
+crime
+crisp
+critic
+crop
+cross
+crouch
+crowd
+crucial
+cruel
+cruise
+crumble
+crunch
+crush
+cry
+crystal
+cube
+culture
+cup
+cupboard
+curious
+current
+curtain
+curve
+cushion
+custom
+cute
+cycle
+dad
+damage
+damp
+dance
+danger
+daring
+dash
+daughter
+dawn
+day
+deal
+debate
+debris
+decade
+december
+decide
+decline
+decorate
+decrease
+deer
+defense
+define
+defy
+degree
+delay
+deliver
+demand
+demise
+denial
+dentist
+deny
+depart
+depend
+deposit
+depth
+deputy
+derive
+describe
+desert
+design
+desk
+despair
+destroy
+detail
+detect
+develop
+device
+devote
+diagram
+dial
+diamond
+diary
+dice
+diesel
+diet
+differ
+digital
+dignity
+dilemma
+dinner
+dinosaur
+direct
+dirt
+disagree
+discover
+disease
+dish
+dismiss
+disorder
+display
+distance
+divert
+divide
+divorce
+dizzy
+doctor
+document
+dog
+doll
+dolphin
+domain
+donate
+donkey
+donor
+door
+dose
+double
+dove
+draft
+dragon
+drama
+drastic
+draw
+dream
+dress
+drift
+drill
+drink
+drip
+drive
+drop
+drum
+dry
+duck
+dumb
+dune
+during
+dust
+dutch
+duty
+dwarf
+dynamic
+eager
+eagle
+early
+earn
+earth
+easily
+east
+easy
+echo
+ecology
+economy
+edge
+edit
+educate
+effort
+egg
+eight
+either
+elbow
+elder
+electric
+elegant
+element
+elephant
+elevator
+elite
+else
+embark
+embody
+embrace
+emerge
+emotion
+employ
+empower
+empty
+enable
+enact
+end
+endless
+endorse
+enemy
+energy
+enforce
+engage
+engine
+enhance
+enjoy
+enlist
+enough
+enrich
+enroll
+ensure
+enter
+entire
+entry
+envelope
+episode
+equal
+equip
+era
+erase
+erode
+erosion
+error
+erupt
+escape
+essay
+essence
+estate
+eternal
+ethics
+evidence
+evil
+evoke
+evolve
+exact
+example
+excess
+exchange
+excite
+exclude
+excuse
+execute
+exercise
+exhaust
+exhibit
+exile
+exist
+exit
+exotic
+expand
+expect
+expire
+explain
+expose
+express
+extend
+extra
+eye
+eyebrow
+fabric
+face
+faculty
+fade
+faint
+faith
+fall
+false
+fame
+family
+famous
+fan
+fancy
+fantasy
+farm
+fashion
+fat
+fatal
+father
+fatigue
+fault
+favorite
+feature
+february
+federal
+fee
+feed
+feel
+female
+fence
+festival
+fetch
+fever
+few
+fiber
+fiction
+field
+figure
+file
+film
+filter
+final
+find
+fine
+finger
+finish
+fire
+firm
+first
+fiscal
+fish
+fit
+fitness
+fix
+flag
+flame
+flash
+flat
+flavor
+flee
+flight
+flip
+float
+flock
+floor
+flower
+fluid
+flush
+fly
+foam
+focus
+fog
+foil
+fold
+follow
+food
+foot
+force
+forest
+forget
+fork
+fortune
+forum
+forward
+fossil
+foster
+found
+fox
+fragile
+frame
+frequent
+fresh
+friend
+fringe
+frog
+front
+frost
+frown
+frozen
+fruit
+fuel
+fun
+funny
+furnace
+fury
+future
+gadget
+gain
+galaxy
+gallery
+game
+gap
+garage
+garbage
+garden
+garlic
+garment
+gas
+gasp
+gate
+gather
+gauge
+gaze
+general
+genius
+genre
+gentle
+genuine
+gesture
+ghost
+giant
+gift
+giggle
+ginger
+giraffe
+girl
+give
+glad
+glance
+glare
+glass
+glide
+glimpse
+globe
+gloom
+glory
+glove
+glow
+glue
+goat
+goddess
+gold
+good
+goose
+gorilla
+gospel
+gossip
+govern
+gown
+grab
+grace
+grain
+grant
+grape
+grass
+gravity
+great
+green
+grid
+grief
+grit
+grocery
+group
+grow
+grunt
+guard
+guess
+guide
+guilt
+guitar
+gun
+gym
+habit
+hair
+half
+hammer
+hamster
+hand
+happy
+harbor
+hard
+harsh
+harvest
+hat
+have
+hawk
+hazard
+head
+health
+heart
+heavy
+hedgehog
+height
+hello
+helmet
+help
+hen
+hero
+hidden
+high
+hill
+hint
+hip
+hire
+history
+hobby
+hockey
+hold
+hole
+holiday
+hollow
+home
+honey
+hood
+hope
+horn
+horror
+horse
+hospital
+host
+hotel
+hour
+hover
+hub
+huge
+human
+humble
+humor
+hundred
+hungry
+hunt
+hurdle
+hurry
+hurt
+husband
+hybrid
+ice
+icon
+idea
+identify
+idle
+ignore
+ill
+illegal
+illness
+image
+imitate
+immense
+immune
+impact
+impose
+improve
+impulse
+inch
+include
+income
+increase
+index
+indicate
+indoor
+industry
+infant
+inflict
+inform
+inhale
+inherit
+initial
+inject
+injury
+inmate
+inner
+innocent
+input
+inquiry
+insane
+insect
+inside
+inspire
+install
+intact
+interest
+into
+invest
+invite
+involve
+iron
+island
+isolate
+issue
+item
+ivory
+jacket
+jaguar
+jar
+jazz
+jealous
+jeans
+jelly
+jewel
+job
+join
+joke
+journey
+joy
+judge
+juice
+jump
+jungle
+junior
+junk
+just
+kangaroo
+keen
+keep
+ketchup
+key
+kick
+kid
+kidney
+kind
+kingdom
+kiss
+kit
+kitchen
+kite
+kitten
+kiwi
+knee
+knife
+knock
+know
+lab
+label
+labor
+ladder
+lady
+lake
+lamp
+language
+laptop
+large
+later
+latin
+laugh
+laundry
+lava
+law
+lawn
+lawsuit
+layer
+lazy
+leader
+leaf
+learn
+leave
+lecture
+left
+leg
+legal
+legend
+leisure
+lemon
+lend
+length
+lens
+leopard
+lesson
+letter
+level
+liar
+liberty
+library
+license
+life
+lift
+light
+like
+limb
+limit
+link
+lion
+liquid
+list
+little
+live
+lizard
+load
+loan
+lobster
+local
+lock
+logic
+lonely
+long
+loop
+lottery
+loud
+lounge
+love
+loyal
+lucky
+luggage
+lumber
+lunar
+lunch
+luxury
+lyrics
+machine
+mad
+magic
+magnet
+maid
+mail
+main
+major
+make
+mammal
+man
+manage
+mandate
+mango
+mansion
+manual
+maple
+marble
+march
+margin
+marine
+market
+marriage
+mask
+mass
+master
+match
+material
+math
+matrix
+matter
+maximum
+maze
+meadow
+mean
+measure
+meat
+mechanic
+medal
+media
+melody
+melt
+member
+memory
+mention
+menu
+mercy
+merge
+merit
+merry
+mesh
+message
+metal
+method
+middle
+midnight
+milk
+million
+mimic
+mind
+minimum
+minor
+minute
+miracle
+mirror
+misery
+miss
+mistake
+mix
+mixed
+mixture
+mobile
+model
+modify
+mom
+moment
+monitor
+monkey
+monster
+month
+moon
+moral
+more
+morning
+mosquito
+mother
+motion
+motor
+mountain
+mouse
+move
+movie
+much
+muffin
+mule
+multiply
+muscle
+museum
+mushroom
+music
+must
+mutual
+myself
+mystery
+myth
+naive
+name
+napkin
+narrow
+nasty
+nation
+nature
+near
+neck
+need
+negative
+neglect
+neither
+nephew
+nerve
+nest
+net
+network
+neutral
+never
+news
+next
+nice
+night
+noble
+noise
+nominee
+noodle
+normal
+north
+nose
+notable
+note
+nothing
+notice
+novel
+now
+nuclear
+number
+nurse
+nut
+oak
+obey
+object
+oblige
+obscure
+observe
+obtain
+obvious
+occur
+ocean
+october
+odor
+off
+offer
+office
+often
+oil
+okay
+old
+olive
+olympic
+omit
+once
+one
+onion
+online
+only
+open
+opera
+opinion
+oppose
+option
+orange
+orbit
+orchard
+order
+ordinary
+organ
+orient
+original
+orphan
+ostrich
+other
+outdoor
+outer
+output
+outside
+oval
+oven
+over
+own
+owner
+oxygen
+oyster
+ozone
+pact
+paddle
+page
+pair
+palace
+palm
+panda
+panel
+panic
+panther
+paper
+parade
+parent
+park
+parrot
+party
+pass
+patch
+path
+patient
+patrol
+pattern
+pause
+pave
+payment
+peace
+peanut
+pear
+peasant
+pelican
+pen
+penalty
+pencil
+people
+pepper
+perfect
+permit
+person
+pet
+phone
+photo
+phrase
+physical
+piano
+picnic
+picture
+piece
+pig
+pigeon
+pill
+pilot
+pink
+pioneer
+pipe
+pistol
+pitch
+pizza
+place
+planet
+plastic
+plate
+play
+please
+pledge
+pluck
+plug
+plunge
+poem
+poet
+point
+polar
+pole
+police
+pond
+pony
+pool
+popular
+portion
+position
+possible
+post
+potato
+pottery
+poverty
+powder
+power
+practice
+praise
+predict
+prefer
+prepare
+present
+pretty
+prevent
+price
+pride
+primary
+print
+priority
+prison
+private
+prize
+problem
+process
+produce
+profit
+program
+project
+promote
+proof
+property
+prosper
+protect
+proud
+provide
+public
+pudding
+pull
+pulp
+pulse
+pumpkin
+punch
+pupil
+puppy
+purchase
+purity
+purpose
+purse
+push
+put
+puzzle
+pyramid
+quality
+quantum
+quarter
+question
+quick
+quit
+quiz
+quote
+rabbit
+raccoon
+race
+rack
+radar
+radio
+rail
+rain
+raise
+rally
+ramp
+ranch
+random
+range
+rapid
+rare
+rate
+rather
+raven
+raw
+razor
+ready
+real
+reason
+rebel
+rebuild
+recall
+receive
+recipe
+record
+recycle
+reduce
+reflect
+reform
+refuse
+region
+regret
+regular
+reject
+relax
+release
+relief
+rely
+remain
+remember
+remind
+remove
+render
+renew
+rent
+reopen
+repair
+repeat
+replace
+report
+require
+rescue
+resemble
+resist
+resource
+response
+result
+retire
+retreat
+return
+reunion
+reveal
+review
+reward
+rhythm
+rib
+ribbon
+rice
+rich
+ride
+ridge
+rifle
+right
+rigid
+ring
+riot
+ripple
+risk
+ritual
+rival
+river
+road
+roast
+robot
+robust
+rocket
+romance
+roof
+rookie
+room
+rose
+rotate
+rough
+round
+route
+royal
+rubber
+rude
+rug
+rule
+run
+runway
+rural
+sad
+saddle
+sadness
+safe
+sail
+salad
+salmon
+salon
+salt
+salute
+same
+sample
+sand
+satisfy
+satoshi
+sauce
+sausage
+save
+say
+scale
+scan
+scare
+scatter
+scene
+scheme
+school
+science
+scissors
+scorpion
+scout
+scrap
+screen
+script
+scrub
+sea
+search
+season
+seat
+second
+secret
+section
+security
+seed
+seek
+segment
+select
+sell
+seminar
+senior
+sense
+sentence
+series
+service
+session
+settle
+setup
+seven
+shadow
+shaft
+shallow
+share
+shed
+shell
+sheriff
+shield
+shift
+shine
+ship
+shiver
+shock
+shoe
+shoot
+shop
+short
+shoulder
+shove
+shrimp
+shrug
+shuffle
+shy
+sibling
+sick
+side
+siege
+sight
+sign
+silent
+silk
+silly
+silver
+similar
+simple
+since
+sing
+siren
+sister
+situate
+six
+size
+skate
+sketch
+ski
+skill
+skin
+skirt
+skull
+slab
+slam
+sleep
+slender
+slice
+slide
+slight
+slim
+slogan
+slot
+slow
+slush
+small
+smart
+smile
+smoke
+smooth
+snack
+snake
+snap
+sniff
+snow
+soap
+soccer
+social
+sock
+soda
+soft
+solar
+soldier
+solid
+solution
+solve
+someone
+song
+soon
+sorry
+sort
+soul
+sound
+soup
+source
+south
+space
+spare
+spatial
+spawn
+speak
+special
+speed
+spell
+spend
+sphere
+spice
+spider
+spike
+spin
+spirit
+split
+spoil
+sponsor
+spoon
+sport
+spot
+spray
+spread
+spring
+spy
+square
+squeeze
+squirrel
+stable
+stadium
+staff
+stage
+stairs
+stamp
+stand
+start
+state
+stay
+steak
+steel
+stem
+step
+stereo
+stick
+still
+sting
+stock
+stomach
+stone
+stool
+story
+stove
+strategy
+street
+strike
+strong
+struggle
+student
+stuff
+stumble
+style
+subject
+submit
+subway
+success
+such
+sudden
+suffer
+sugar
+suggest
+suit
+summer
+sun
+sunny
+sunset
+super
+supply
+supreme
+sure
+surface
+surge
+surprise
+surround
+survey
+suspect
+sustain
+swallow
+swamp
+swap
+swarm
+swear
+sweet
+swift
+swim
+swing
+switch
+sword
+symbol
+symptom
+syrup
+system
+table
+tackle
+tag
+tail
+talent
+talk
+tank
+tape
+target
+task
+taste
+tattoo
+taxi
+teach
+team
+tell
+ten
+tenant
+tennis
+tent
+term
+test
+text
+thank
+that
+theme
+then
+theory
+there
+they
+thing
+this
+thought
+three
+thrive
+throw
+thumb
+thunder
+ticket
+tide
+tiger
+tilt
+timber
+time
+tiny
+tip
+tired
+tissue
+title
+toast
+tobacco
+today
+toddler
+toe
+together
+toilet
+token
+tomato
+tomorrow
+tone
+tongue
+tonight
+tool
+tooth
+top
+topic
+topple
+torch
+tornado
+tortoise
+toss
+total
+tourist
+toward
+tower
+town
+toy
+track
+trade
+traffic
+tragic
+train
+transfer
+trap
+trash
+travel
+tray
+treat
+tree
+trend
+trial
+tribe
+trick
+trigger
+trim
+trip
+trophy
+trouble
+truck
+true
+truly
+trumpet
+trust
+truth
+try
+tube
+tuition
+tumble
+tuna
+tunnel
+turkey
+turn
+turtle
+twelve
+twenty
+twice
+twin
+twist
+two
+type
+typical
+ugly
+umbrella
+unable
+unaware
+uncle
+uncover
+under
+undo
+unfair
+unfold
+unhappy
+uniform
+unique
+unit
+universe
+unknown
+unlock
+until
+unusual
+unveil
+update
+upgrade
+uphold
+upon
+upper
+upset
+urban
+urge
+usage
+use
+used
+useful
+useless
+usual
+utility
+vacant
+vacuum
+vague
+valid
+valley
+valve
+van
+vanish
+vapor
+various
+vast
+vault
+vehicle
+velvet
+vendor
+venture
+venue
+verb
+verify
+version
+very
+vessel
+veteran
+viable
+vibrant
+vicious
+victory
+video
+view
+village
+vintage
+violin
+virtual
+virus
+visa
+visit
+visual
+vital
+vivid
+vocal
+voice
+void
+volcano
+volume
+vote
+voyage
+wage
+wagon
+wait
+walk
+wall
+walnut
+want
+warfare
+warm
+warrior
+wash
+wasp
+waste
+water
+wave
+way
+wealth
+weapon
+wear
+weasel
+weather
+web
+wedding
+weekend
+weird
+welcome
+west
+wet
+whale
+what
+wheat
+wheel
+when
+where
+whip
+whisper
+wide
+width
+wife
+wild
+will
+win
+window
+wine
+wing
+wink
+winner
+winter
+wire
+wisdom
+wise
+wish
+witness
+wolf
+woman
+wonder
+wood
+wool
+word
+work
+world
+worry
+worth
+wrap
+wreck
+wrestle
+wrist
+write
+wrong
+yard
+year
+yellow
+you
+young
+youth
+zebra
+zero
+zone
+zoo`

vendor/vendor.json

@@ -103,6 +103,12 @@
 			"revision": "8e610b2b55bfd1bfa9436ab110d311f5e8a74dcb",
 			"revisionTime": "2018-06-25T18:44:42Z"
 		},
+		{
+			"checksumSHA1": "B1sVd5XOmjuSFYivGhBd+vPlc1w=",
+			"path": "github.com/ebfe/scard",
+			"revision": "0147d7ead790ac8a5ecc91ee6de68beb7b17c4e9",
+			"revisionTime": "2017-12-31T19:32:11Z"
+		},
 		{
 			"checksumSHA1": "zYnPsNAVm1/ViwCkN++dX2JQhBo=",
 			"path": "github.com/edsrzf/mmap-go",
@@ -615,6 +621,18 @@
 			"revision": "a51202d6f4a7e5a219e3841a43614ff7187ae7f1",
 			"revisionTime": "2018-06-15T20:27:29Z"
 		},
+		{
+			"checksumSHA1": "vW7IiPtoA4hQQ/ScHlbmRktY89U=",
+			"path": "github.com/tyler-smith/go-bip39",
+			"revision": "8e7a99b3e716f36d3b080a9a70f9eb45abe4edcc",
+			"revisionTime": "2016-06-29T16:38:56Z"
+		},
+		{
+			"checksumSHA1": "GLCPuvePAkWT+opcWq3mNdhOfGM=",
+			"path": "github.com/wsddn/go-ecdh",
+			"revision": "48726bab92085232373de4ec5c51ce7b441c63a0",
+			"revisionTime": "2016-12-11T03:23:59Z"
+		},
 		{
 			"checksumSHA1": "TT1rac6kpQp2vz24m5yDGUNQ/QQ=",
 			"path": "golang.org/x/crypto/cast5",