Merge remote-tracking branch 'refs/remotes/ethereum/master' into rebase-1.5.9

VERSION

@@ -1 +1 @@
-1.5.10
+1.6.0

accounts/keystore/key.go

@@ -32,7 +32,6 @@ import (
 	"github.com/expanse-org/go-expanse/accounts"
 	"github.com/expanse-org/go-expanse/common"
 	"github.com/expanse-org/go-expanse/crypto"
-	"github.com/expanse-org/go-expanse/crypto/secp256k1"
 	"github.com/pborman/uuid"
 )
 
@@ -157,7 +156,7 @@ func NewKeyForDirectICAP(rand io.Reader) *Key {
 		panic("key generation: could not read from random source: " + err.Error())
 	}
 	reader := bytes.NewReader(randBytes)
-	privateKeyECDSA, err := ecdsa.GenerateKey(secp256k1.S256(), reader)
+	privateKeyECDSA, err := ecdsa.GenerateKey(crypto.S256(), reader)
 	if err != nil {
 		panic("key generation: ecdsa.GenerateKey failed: " + err.Error())
 	}
@@ -169,7 +168,7 @@ func NewKeyForDirectICAP(rand io.Reader) *Key {
 }
 
 func newKey(rand io.Reader) (*Key, error) {
-	privateKeyECDSA, err := ecdsa.GenerateKey(secp256k1.S256(), rand)
+	privateKeyECDSA, err := ecdsa.GenerateKey(crypto.S256(), rand)
 	if err != nil {
 		return nil, err
 	}

accounts/usbwallet/ledger_hub.go

@@ -18,18 +18,16 @@
 // wallets. The wire protocol spec can be found in the Ledger Blue GitHub repo:
 // https://raw.githubusercontent.com/LedgerHQ/blue-app-eth/master/doc/ethapp.asc
 
-// +build !ios
-
 package usbwallet
 
 import (
-	"fmt"
+	"errors"
 	"sync"
 	"time"
 
 	"github.com/expanse-org/go-expanse/accounts"
 	"github.com/expanse-org/go-expanse/event"
-	"github.com/karalabe/gousb/usb"
+	"github.com/karalabe/hid"
 )
 
 // LedgerScheme is the protocol scheme prefixing account and wallet URLs.
@@ -49,8 +47,6 @@ const ledgerRefreshThrottling = 500 * time.Millisecond
 
 // LedgerHub is a accounts.Backend that can find and handle Ledger hardware wallets.
 type LedgerHub struct {
-	ctx *usb.Context // Context interfacing with a libusb instance
-
 	refreshed   time.Time               // Time instance when the list of wallets was last refreshed
 	wallets     []accounts.Wallet       // List of Ledger devices currently tracking
 	updateFeed  event.Feed              // Event feed to notify wallet additions/removals
@@ -63,18 +59,13 @@ type LedgerHub struct {
 
 // NewLedgerHub creates a new hardware wallet manager for Ledger devices.
 func NewLedgerHub() (*LedgerHub, error) {
-	// Initialize the USB library to access Ledgers through
+	if !hid.Supported() {
-	ctx, err := usb.NewContext()
+		return nil, errors.New("unsupported platform")
-	if err != nil {
-		return nil, err
 	}
-	// Create the USB hub, start and return it
 	hub := &LedgerHub{
-		ctx:  ctx,
 		quit: make(chan chan error),
 	}
 	hub.refreshWallets()
-
 	return hub, nil
 }
 
@@ -104,31 +95,23 @@ func (hub *LedgerHub) refreshWallets() {
 		return
 	}
 	// Retrieve the current list of Ledger devices
-	var devIDs []deviceID
+	var ledgers []hid.DeviceInfo
-	var busIDs []uint16
+	for _, info := range hid.Enumerate(0, 0) { // Can't enumerate directly, one valid ID is the 0 wildcard
-
-	hub.ctx.ListDevices(func(desc *usb.Descriptor) bool {
-		// Gather Ledger devices, don't connect any just yet
 		for _, id := range ledgerDeviceIDs {
-			if desc.Vendor == id.Vendor && desc.Product == id.Product {
+			if info.VendorID == id.Vendor && info.ProductID == id.Product {
-				devIDs = append(devIDs, deviceID{Vendor: desc.Vendor, Product: desc.Product})
+				ledgers = append(ledgers, info)
-				busIDs = append(busIDs, uint16(desc.Bus)<<8+uint16(desc.Address))
+				break
-				return false
+			}
 		}
 	}
-		// Not ledger, ignore and don't connect either
-		return false
-	})
 	// Transform the current list of wallets into the new one
 	hub.lock.Lock()
 
-	wallets := make([]accounts.Wallet, 0, len(devIDs))
+	wallets := make([]accounts.Wallet, 0, len(ledgers))
 	events := []accounts.WalletEvent{}
 
-	for i := 0; i < len(devIDs); i++ {
+	for _, ledger := range ledgers {
-		devID, busID := devIDs[i], busIDs[i]
+		url := accounts.URL{Scheme: LedgerScheme, Path: ledger.Path}
-
-		url := accounts.URL{Scheme: LedgerScheme, Path: fmt.Sprintf("%03d:%03d", busID>>8, busID&0xff)}
 
 		// Drop wallets in front of the next device or those that failed for some reason
 		for len(hub.wallets) > 0 && (hub.wallets[0].URL().Cmp(url) < 0 || hub.wallets[0].(*ledgerWallet).failed()) {
@@ -137,7 +120,7 @@ func (hub *LedgerHub) refreshWallets() {
 		}
 		// If there are no more wallets or the device is before the next, wrap new wallet
 		if len(hub.wallets) == 0 || hub.wallets[0].URL().Cmp(url) > 0 {
-			wallet := &ledgerWallet{context: hub.ctx, hardwareID: devID, locationID: busID, url: &url}
+			wallet := &ledgerWallet{url: &url, info: ledger}
 
 			events = append(events, accounts.WalletEvent{Wallet: wallet, Arrive: true})
 			wallets = append(wallets, wallet)

accounts/usbwallet/ledger_wallet.go

@@ -18,8 +18,6 @@
 // wallets. The wire protocol spec can be found in the Ledger Blue GitHub repo:
 // https://raw.githubusercontent.com/LedgerHQ/blue-app-eth/master/doc/ethapp.asc
 
-// +build !ios
-
 package usbwallet
 
 import (
@@ -39,7 +37,7 @@ import (
 	"github.com/expanse-org/go-expanse/logger"
 	"github.com/expanse-org/go-expanse/logger/glog"
 	"github.com/expanse-org/go-expanse/rlp"
-	"github.com/karalabe/gousb/usb"
+	"github.com/karalabe/hid"
 	"golang.org/x/net/context"
 )
 
@@ -74,21 +72,21 @@ const (
 	ledgerP2ReturnAddressChainCode  ledgerParam2 = 0x01 // Require a user confirmation before returning the address
 )
 
-// errReplyInvalidHeader is the error message returned by a Ledfer data exchange
+// errReplyInvalidHeader is the error message returned by a Ledger data exchange
 // if the device replies with a mismatching header. This usually means the device
 // is in browser mode.
 var errReplyInvalidHeader = errors.New("invalid reply header")
 
+// errInvalidVersionReply is the error message returned by a Ledger version retrieval
+// when a response does arrive, but it does not contain the expected data.
+var errInvalidVersionReply = errors.New("invalid version reply")
+
 // ledgerWallet represents a live USB Ledger hardware wallet.
 type ledgerWallet struct {
-	context    *usb.Context  // USB context to interface libusb through
-	hardwareID deviceID      // USB identifiers to identify this device type
-	locationID uint16        // USB bus and address to identify this device instance
 	url *accounts.URL // Textual URL uniquely identifying this wallet
 
-	device  *usb.Device  // USB device advertising itself as a Ledger wallet
+	info    hid.DeviceInfo // Known USB device infos about the wallet
-	input   usb.Endpoint // Input endpoint to send data to this device
+	device  *hid.Device    // USB device advertising itself as a Ledger wallet
-	output  usb.Endpoint // Output endpoint to receive data from this device
 	failure error          // Any failure that would make the device unusable
 
 	version  [3]byte                                    // Current version of the Ledger Ethereum app (zero if app is offline)
@@ -183,59 +181,12 @@ func (w *ledgerWallet) Open(passphrase string) error {
 		return accounts.ErrWalletAlreadyOpen
 	}
 	// Otherwise iterate over all USB devices and find this again (no way to directly do this)
-	// Iterate over all attached devices and fetch those seemingly Ledger
+	device, err := w.info.Open()
-	devices, err := w.context.ListDevices(func(desc *usb.Descriptor) bool {
-		// Only open this single specific device
-		return desc.Vendor == w.hardwareID.Vendor && desc.Product == w.hardwareID.Product &&
-			uint16(desc.Bus)<<8+uint16(desc.Address) == w.locationID
-	})
 	if err != nil {
 		return err
 	}
-	if len(devices) == 0 {
-		return accounts.ErrUnknownWallet
-	}
-	// Device opened, attach to the input and output endpoints
-	device := devices[0]
-
-	var invalid string
-	switch {
-	case len(device.Descriptor.Configs) == 0:
-		invalid = "no endpoint config available"
-	case len(device.Descriptor.Configs[0].Interfaces) == 0:
-		invalid = "no endpoint interface available"
-	case len(device.Descriptor.Configs[0].Interfaces[0].Setups) == 0:
-		invalid = "no endpoint setup available"
-	case len(device.Descriptor.Configs[0].Interfaces[0].Setups[0].Endpoints) < 2:
-		invalid = "not enough IO endpoints available"
-	}
-	if invalid != "" {
-		device.Close()
-		return fmt.Errorf("ledger wallet [%s] invalid: %s", w.url, invalid)
-	}
-	// Open the input and output endpoints to the device
-	input, err := device.OpenEndpoint(
-		device.Descriptor.Configs[0].Config,
-		device.Descriptor.Configs[0].Interfaces[0].Number,
-		device.Descriptor.Configs[0].Interfaces[0].Setups[0].Number,
-		device.Descriptor.Configs[0].Interfaces[0].Setups[0].Endpoints[1].Address,
-	)
-	if err != nil {
-		device.Close()
-		return fmt.Errorf("ledger wallet [%s] input open failed: %v", w.url, err)
-	}
-	output, err := device.OpenEndpoint(
-		device.Descriptor.Configs[0].Config,
-		device.Descriptor.Configs[0].Interfaces[0].Number,
-		device.Descriptor.Configs[0].Interfaces[0].Setups[0].Number,
-		device.Descriptor.Configs[0].Interfaces[0].Setups[0].Endpoints[0].Address,
-	)
-	if err != nil {
-		device.Close()
-		return fmt.Errorf("ledger wallet [%s] output open failed: %v", w.url, err)
-	}
 	// Wallet seems to be successfully opened, guess if the Ethereum app is running
-	w.device, w.input, w.output = device, input, output
+	w.device = device
 	w.commsLock = make(chan struct{}, 1)
 	w.commsLock <- struct{}{} // Enable lock
 
@@ -298,13 +249,13 @@ func (w *ledgerWallet) heartbeat() {
 		w.commsLock <- struct{}{}
 		w.stateLock.RUnlock()
 
-		if err == usb.ERROR_IO || err == usb.ERROR_NO_DEVICE {
+		if err != nil && err != errInvalidVersionReply {
 			w.stateLock.Lock() // Lock state to tear the wallet down
 			w.failure = err
 			w.close()
 			w.stateLock.Unlock()
 		}
-		// Ignore uninteresting errors
+		// Ignore non hardware related errors
 		err = nil
 	}
 	// In case of error, wait for termination
@@ -363,13 +314,13 @@ func (w *ledgerWallet) close() error {
 		return nil
 	}
 	// Close the device, clear everything, then return
-	err := w.device.Close()
+	w.device.Close()
+	w.device = nil
 
-	w.device, w.input, w.output = nil, nil, nil
 	w.browser, w.version = false, [3]byte{}
 	w.accounts, w.paths = nil, nil
 
-	return err
+	return nil
 }
 
 // Accounts implements accounts.Wallet, returning the list of accounts pinned to
@@ -664,7 +615,7 @@ func (w *ledgerWallet) ledgerVersion() ([3]byte, error) {
 		return [3]byte{}, err
 	}
 	if len(reply) != 4 {
-		return [3]byte{}, errors.New("reply not of correct size")
+		return [3]byte{}, errInvalidVersionReply
 	}
 	// Cache the version for future reference
 	var version [3]byte
@@ -768,10 +719,6 @@ func (w *ledgerWallet) ledgerDerive(derivationPath []uint32) (common.Address, er
 //   signature R | 32 bytes
 //   signature S | 32 bytes
 func (w *ledgerWallet) ledgerSign(derivationPath []uint32, address common.Address, tx *types.Transaction, chainID *big.Int) (*types.Transaction, error) {
-	// We need to modify the timeouts to account for user feedback
-	defer func(old time.Duration) { w.device.ReadTimeout = old }(w.device.ReadTimeout)
-	w.device.ReadTimeout = time.Hour * 24 * 30 // Timeout requires a Ledger power cycle, only if you must
-
 	// Flatten the derivation path into the Ledger request
 	path := make([]byte, 1+4*len(derivationPath))
 	path[0] = byte(len(derivationPath))
@@ -903,9 +850,9 @@ func (w *ledgerWallet) ledgerExchange(opcode ledgerOpcode, p1 ledgerParam1, p2 l
 		}
 		// Send over to the device
 		if glog.V(logger.Detail) {
-			glog.Infof("-> %03d.%03d: %x", w.device.Bus, w.device.Address, chunk)
+			glog.Infof("-> %s: %x", w.device.Path, chunk)
 		}
-		if _, err := w.input.Write(chunk); err != nil {
+		if _, err := w.device.Write(chunk); err != nil {
 			return nil, err
 		}
 	}
@@ -914,11 +861,11 @@ func (w *ledgerWallet) ledgerExchange(opcode ledgerOpcode, p1 ledgerParam1, p2 l
 	chunk = chunk[:64] // Yeah, we surely have enough space
 	for {
 		// Read the next chunk from the Ledger wallet
-		if _, err := io.ReadFull(w.output, chunk); err != nil {
+		if _, err := io.ReadFull(w.device, chunk); err != nil {
 			return nil, err
 		}
 		if glog.V(logger.Detail) {
-			glog.Infof("<- %03d.%03d: %x", w.device.Bus, w.device.Address, chunk)
+			glog.Infof("<- %s: %x", w.device.Path, chunk)
 		}
 		// Make sure the transport header matches
 		if chunk[0] != 0x01 || chunk[1] != 0x01 || chunk[2] != 0x05 {

accounts/usbwallet/usbwallet.go

@@ -14,16 +14,12 @@
 // 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/>.
 
-// +build !ios
-
 // Package usbwallet implements support for USB hardware wallets.
 package usbwallet
 
-import "github.com/karalabe/gousb/usb"
-
 // deviceID is a combined vendor/product identifier to uniquely identify a USB
 // hardware device.
 type deviceID struct {
-	Vendor  usb.ID // The Vendor identifer
+	Vendor  uint16 // The Vendor identifer
-	Product usb.ID // The Product identifier
+	Product uint16 // The Product identifier
 }

cmd/geth/bugcmd.go

@@ -0,0 +1,108 @@
+// Copyright 2017 The go-ethereum Authors
+// This file is part of go-ethereum.
+//
+// go-ethereum is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// go-ethereum 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 General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with go-ethereum. If not, see <http://www.gnu.org/licenses/>.
+
+package main
+
+import (
+	"bytes"
+	"fmt"
+	"io"
+	"io/ioutil"
+	"net/url"
+	"os/exec"
+	"runtime"
+	"strings"
+
+	"github.com/ethereum/go-ethereum/cmd/internal/browser"
+	"github.com/ethereum/go-ethereum/params"
+
+	cli "gopkg.in/urfave/cli.v1"
+)
+
+var bugCommand = cli.Command{
+	Action:    reportBug,
+	Name:      "bug",
+	Usage:     "opens a window to report a bug on the geth repo",
+	ArgsUsage: " ",
+	Category:  "MISCELLANEOUS COMMANDS",
+}
+
+const issueUrl = "https://github.com/ethereum/go-ethereum/issues/new"
+
+// reportBug reports a bug by opening a new URL to the go-ethereum GH issue
+// tracker and setting default values as the issue body.
+func reportBug(ctx *cli.Context) error {
+	// execute template and write contents to buff
+	var buff bytes.Buffer
+
+	fmt.Fprintln(&buff, header)
+	fmt.Fprintln(&buff, "Version:", params.Version)
+	fmt.Fprintln(&buff, "Go Version:", runtime.Version())
+	fmt.Fprintln(&buff, "OS:", runtime.GOOS)
+	printOSDetails(&buff)
+
+	// open a new GH issue
+	if !browser.Open(issueUrl + "?body=" + url.QueryEscape(buff.String())) {
+		fmt.Printf("Please file a new issue at %s using this template:\n%s", issueUrl, buff.String())
+	}
+	return nil
+}
+
+// copied from the Go source. Copyright 2017 The Go Authors
+func printOSDetails(w io.Writer) {
+	switch runtime.GOOS {
+	case "darwin":
+		printCmdOut(w, "uname -v: ", "uname", "-v")
+		printCmdOut(w, "", "sw_vers")
+	case "linux":
+		printCmdOut(w, "uname -sr: ", "uname", "-sr")
+		printCmdOut(w, "", "lsb_release", "-a")
+	case "openbsd", "netbsd", "freebsd", "dragonfly":
+		printCmdOut(w, "uname -v: ", "uname", "-v")
+	case "solaris":
+		out, err := ioutil.ReadFile("/etc/release")
+		if err == nil {
+			fmt.Fprintf(w, "/etc/release: %s\n", out)
+		} else {
+			fmt.Printf("failed to read /etc/release: %v\n", err)
+		}
+	}
+}
+
+// printCmdOut prints the output of running the given command.
+// It ignores failures; 'go bug' is best effort.
+//
+// copied from the Go source. Copyright 2017 The Go Authors
+func printCmdOut(w io.Writer, prefix, path string, args ...string) {
+	cmd := exec.Command(path, args...)
+	out, err := cmd.Output()
+	if err != nil {
+		fmt.Printf("%s %s: %v\n", path, strings.Join(args, " "), err)
+		return
+	}
+	fmt.Fprintf(w, "%s%s\n", prefix, bytes.TrimSpace(out))
+}
+
+const header = `Please answer these questions before submitting your issue. Thanks!
+
+#### What did you do?
+ 
+#### What did you expect to see?
+ 
+#### What did you see instead?
+ 
+#### System details
+`

cmd/gexp/main.go

@@ -81,6 +81,7 @@ func init() {
 		// See misccmd.go:
 		makedagCommand,
 		versionCommand,
+		bugCommand,
 		licenseCommand,
 	}
 

cmd/internal/browser/browser.go

@@ -0,0 +1,46 @@
+// Copyright 2016 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Package browser provides utilities for interacting with users' browsers.
+package browser
+
+import (
+	"os"
+	"os/exec"
+	"runtime"
+)
+
+// Commands returns a list of possible commands to use to open a url.
+func Commands() [][]string {
+	var cmds [][]string
+	if exe := os.Getenv("BROWSER"); exe != "" {
+		cmds = append(cmds, []string{exe})
+	}
+	switch runtime.GOOS {
+	case "darwin":
+		cmds = append(cmds, []string{"/usr/bin/open"})
+	case "windows":
+		cmds = append(cmds, []string{"cmd", "/c", "start"})
+	default:
+		cmds = append(cmds, []string{"xdg-open"})
+	}
+	cmds = append(cmds,
+		[]string{"chrome"},
+		[]string{"google-chrome"},
+		[]string{"chromium"},
+		[]string{"firefox"},
+	)
+	return cmds
+}
+
+// Open tries to open url in a browser and reports whether it succeeded.
+func Open(url string) bool {
+	for _, args := range Commands() {
+		cmd := exec.Command(args[0], append(args[1:], url)...)
+		if cmd.Start() == nil {
+			return true
+		}
+	}
+	return false
+}

core/blockchain.go

@@ -597,7 +597,7 @@ func (bc *BlockChain) Stop() {
 func (self *BlockChain) procFutureBlocks() {
 	blocks := make([]*types.Block, 0, self.futureBlocks.Len())
 	for _, hash := range self.futureBlocks.Keys() {
-		if block, exist := self.futureBlocks.Get(hash); exist {
+		if block, exist := self.futureBlocks.Peek(hash); exist {
 			blocks = append(blocks, block.(*types.Block))
 		}
 	}

core/vm/contracts.go

@@ -17,11 +17,14 @@
 package vm
 
 import (
+	"crypto/sha256"
+
 	"github.com/expanse-org/go-expanse/common"
 	"github.com/expanse-org/go-expanse/crypto"
 	"github.com/expanse-org/go-expanse/logger"
 	"github.com/expanse-org/go-expanse/logger/glog"
 	"github.com/expanse-org/go-expanse/params"
+	"golang.org/x/crypto/ripemd160"
 )
 
 // Precompiled contract is the basic interface for native Go contracts. The implementation
@@ -35,8 +38,8 @@ type PrecompiledContract interface {
 // Precompiled contains the default set of ethereum contracts
 var PrecompiledContracts = map[common.Address]PrecompiledContract{
 	common.BytesToAddress([]byte{1}): &ecrecover{},
-	common.BytesToAddress([]byte{2}): &sha256{},
+	common.BytesToAddress([]byte{2}): &sha256hash{},
-	common.BytesToAddress([]byte{3}): &ripemd160{},
+	common.BytesToAddress([]byte{3}): &ripemd160hash{},
 	common.BytesToAddress([]byte{4}): &dataCopy{},
 }
 
@@ -88,31 +91,34 @@ func (c *ecrecover) Run(in []byte) []byte {
 }
 
 // SHA256 implemented as a native contract
-type sha256 struct{}
+type sha256hash struct{}
 
 // RequiredGas returns the gas required to execute the pre-compiled contract.
 //
 // This method does not require any overflow checking as the input size gas costs
 // required for anything significant is so high it's impossible to pay for.
-func (c *sha256) RequiredGas(inputSize int) uint64 {
+func (c *sha256hash) RequiredGas(inputSize int) uint64 {
 	return uint64(inputSize+31)/32*params.Sha256WordGas + params.Sha256Gas
 }
-func (c *sha256) Run(in []byte) []byte {
+func (c *sha256hash) Run(in []byte) []byte {
-	return crypto.Sha256(in)
+	h := sha256.Sum256(in)
+	return h[:]
 }
 
 // RIPMED160 implemented as a native contract
-type ripemd160 struct{}
+type ripemd160hash struct{}
 
 // RequiredGas returns the gas required to execute the pre-compiled contract.
 //
 // This method does not require any overflow checking as the input size gas costs
 // required for anything significant is so high it's impossible to pay for.
-func (c *ripemd160) RequiredGas(inputSize int) uint64 {
+func (c *ripemd160hash) RequiredGas(inputSize int) uint64 {
 	return uint64(inputSize+31)/32*params.Ripemd160WordGas + params.Ripemd160Gas
 }
-func (c *ripemd160) Run(in []byte) []byte {
+func (c *ripemd160hash) Run(in []byte) []byte {
-	return common.LeftPadBytes(crypto.Ripemd160(in), 32)
+	ripemd := ripemd160.New()
+	ripemd.Write(in)
+	return common.LeftPadBytes(ripemd.Sum(nil), 32)
 }
 
 // data copy implemented as a native contract

core/vm/runtime/fuzz.go

@@ -0,0 +1,20 @@
+// +build gofuzz
+
+package runtime
+
+// Fuzz is the basic entry point for the go-fuzz tool
+//
+// This returns 1 for valid parsable/runable code, 0
+// for invalid opcode.
+func Fuzz(input []byte) int {
+	_, _, err := Execute(input, input, &Config{
+		GasLimit: 3000000,
+	})
+
+	// invalid opcode
+	if err != nil && len(err.Error()) > 6 && string(err.Error()[:7]) == "invalid" {
+		return 0
+	}
+
+	return 1
+}

crypto/crypto.go

@@ -20,22 +20,20 @@ import (
 	"crypto/ecdsa"
 	"crypto/elliptic"
 	"crypto/rand"
-	"crypto/sha256"
+	"encoding/hex"
-	"fmt"
+	"errors"
 	"io"
 	"io/ioutil"
 	"math/big"
 	"os"
 
-	"encoding/hex"
-	"errors"
-
 	"github.com/expanse-org/go-expanse/common"
-	"github.com/expanse-org/go-expanse/crypto/ecies"
-	"github.com/expanse-org/go-expanse/crypto/secp256k1"
 	"github.com/expanse-org/go-expanse/crypto/sha3"
 	"github.com/expanse-org/go-expanse/rlp"
-	"golang.org/x/crypto/ripemd160"
+
+var (
+	secp256k1_N, _  = new(big.Int).SetString("fffffffffffffffffffffffffffffffebaaedce6af48a03bbfd25e8cd0364141", 16)
+	secp256k1_halfN = new(big.Int).Div(secp256k1_N, big.NewInt(2))
 )
 
 func Keccak256(data ...[]byte) []byte {
@@ -56,7 +54,6 @@ func Keccak256Hash(data ...[]byte) (h common.Hash) {
 }
 
 // Deprecated: For backward compatibility as other packages depend on these
-func Sha3(data ...[]byte) []byte          { return Keccak256(data...) }
 func Sha3Hash(data ...[]byte) common.Hash { return Keccak256Hash(data...) }
 
 // Creates an ethereum address given the bytes and the nonce
@@ -65,39 +62,16 @@ func CreateAddress(b common.Address, nonce uint64) common.Address {
 	return common.BytesToAddress(Keccak256(data)[12:])
 }
 
-func Sha256(data []byte) []byte {
+// ToECDSA creates a private key with the given D value.
-	hash := sha256.Sum256(data)
-
-	return hash[:]
-}
-
-func Ripemd160(data []byte) []byte {
-	ripemd := ripemd160.New()
-	ripemd.Write(data)
-
-	return ripemd.Sum(nil)
-}
-
-// Ecrecover returns the public key for the private key that was used to
-// calculate the signature.
-//
-// Note: secp256k1 expects the recover id to be either 0, 1. Ethereum
-// signatures have a recover id with an offset of 27. Callers must take
-// this into account and if "recovering" from an Ethereum signature adjust.
-func Ecrecover(hash, sig []byte) ([]byte, error) {
-	return secp256k1.RecoverPubkey(hash, sig)
-}
-
-// New methods using proper ecdsa keys from the stdlib
 func ToECDSA(prv []byte) *ecdsa.PrivateKey {
 	if len(prv) == 0 {
 		return nil
 	}
 
 	priv := new(ecdsa.PrivateKey)
-	priv.PublicKey.Curve = secp256k1.S256()
+	priv.PublicKey.Curve = S256()
 	priv.D = common.BigD(prv)
-	priv.PublicKey.X, priv.PublicKey.Y = secp256k1.S256().ScalarBaseMult(prv)
+	priv.PublicKey.X, priv.PublicKey.Y = priv.PublicKey.Curve.ScalarBaseMult(prv)
 	return priv
 }
 
@@ -112,15 +86,15 @@ func ToECDSAPub(pub []byte) *ecdsa.PublicKey {
 	if len(pub) == 0 {
 		return nil
 	}
-	x, y := elliptic.Unmarshal(secp256k1.S256(), pub)
+	x, y := elliptic.Unmarshal(S256(), pub)
-	return &ecdsa.PublicKey{Curve: secp256k1.S256(), X: x, Y: y}
+	return &ecdsa.PublicKey{Curve: S256(), X: x, Y: y}
 }
 
 func FromECDSAPub(pub *ecdsa.PublicKey) []byte {
 	if pub == nil || pub.X == nil || pub.Y == nil {
 		return nil
 	}
-	return elliptic.Marshal(secp256k1.S256(), pub.X, pub.Y)
+	return elliptic.Marshal(S256(), pub.X, pub.Y)
 }
 
 // HexToECDSA parses a secp256k1 private key.
@@ -164,7 +138,7 @@ func SaveECDSA(file string, key *ecdsa.PrivateKey) error {
 }
 
 func GenerateKey() (*ecdsa.PrivateKey, error) {
-	return ecdsa.GenerateKey(secp256k1.S256(), rand.Reader)
+	return ecdsa.GenerateKey(S256(), rand.Reader)
 }
 
 // ValidateSignatureValues verifies whether the signature values are valid with
@@ -175,49 +149,11 @@ func ValidateSignatureValues(v byte, r, s *big.Int, homestead bool) bool {
 	}
 	// reject upper range of s values (ECDSA malleability)
 	// see discussion in secp256k1/libsecp256k1/include/secp256k1.h
-	if homestead && s.Cmp(secp256k1.HalfN) > 0 {
+	if homestead && s.Cmp(secp256k1_halfN) > 0 {
 		return false
 	}
 	// Frontier: allow s to be in full N range
-	return r.Cmp(secp256k1.N) < 0 && s.Cmp(secp256k1.N) < 0 && (v == 0 || v == 1)
+	return r.Cmp(secp256k1_N) < 0 && s.Cmp(secp256k1_N) < 0 && (v == 0 || v == 1)
-}
-
-func SigToPub(hash, sig []byte) (*ecdsa.PublicKey, error) {
-	s, err := Ecrecover(hash, sig)
-	if err != nil {
-		return nil, err
-	}
-
-	x, y := elliptic.Unmarshal(secp256k1.S256(), s)
-	return &ecdsa.PublicKey{Curve: secp256k1.S256(), X: x, Y: y}, nil
-}
-
-// Sign calculates an ECDSA signature.
-//
-// This function is susceptible to chosen plaintext attacks that can leak
-// information about the private key that is used for signing. Callers must
-// be aware that the given hash cannot be chosen by an adversery. Common
-// solution is to hash any input before calculating the signature.
-//
-// The produced signature is in the [R || S || V] format where V is 0 or 1.
-func Sign(data []byte, prv *ecdsa.PrivateKey) (sig []byte, err error) {
-	if len(data) != 32 {
-		return nil, fmt.Errorf("hash is required to be exactly 32 bytes (%d)", len(data))
-	}
-
-	seckey := common.LeftPadBytes(prv.D.Bytes(), prv.Params().BitSize/8)
-	defer zeroBytes(seckey)
-	sig, err = secp256k1.Sign(data, seckey)
-	return
-}
-
-func Encrypt(pub *ecdsa.PublicKey, message []byte) ([]byte, error) {
-	return ecies.Encrypt(rand.Reader, ecies.ImportECDSAPublic(pub), message, nil, nil)
-}
-
-func Decrypt(prv *ecdsa.PrivateKey, ct []byte) ([]byte, error) {
-	key := ecies.ImportECDSA(prv)
-	return key.Decrypt(rand.Reader, ct, nil, nil)
 }
 
 func PubkeyToAddress(p ecdsa.PublicKey) common.Address {

crypto/crypto_test.go

@@ -27,8 +27,7 @@ import (
 	"testing"
 	"time"
 
-	"github.com/expanse-org/go-expanse/common"
+	"github.com/ethereum/go-ethereum/common"
-	"github.com/expanse-org/go-expanse/crypto/secp256k1"
 )
 
 var testAddrHex = "970e8128ab834e8eac17ab8e3812f010678cf791"
@@ -37,30 +36,12 @@ var testPrivHex = "289c2857d4598e37fb9647507e47a309d6133539bf21a8b9cb6df88fd5232
 // These tests are sanity checks.
 // They should ensure that we don't e.g. use Sha3-224 instead of Sha3-256
 // and that the sha3 library uses keccak-f permutation.
-func TestSha3(t *testing.T) {
-	msg := []byte("abc")
-	exp, _ := hex.DecodeString("4e03657aea45a94fc7d47ba826c8d667c0d1e6e33a64a036ec44f58fa12d6c45")
-	checkhash(t, "Sha3-256", func(in []byte) []byte { return Keccak256(in) }, msg, exp)
-}
-
 func TestSha3Hash(t *testing.T) {
 	msg := []byte("abc")
 	exp, _ := hex.DecodeString("4e03657aea45a94fc7d47ba826c8d667c0d1e6e33a64a036ec44f58fa12d6c45")
 	checkhash(t, "Sha3-256-array", func(in []byte) []byte { h := Keccak256Hash(in); return h[:] }, msg, exp)
 }
 
-func TestSha256(t *testing.T) {
-	msg := []byte("abc")
-	exp, _ := hex.DecodeString("ba7816bf8f01cfea414140de5dae2223b00361a396177a9cb410ff61f20015ad")
-	checkhash(t, "Sha256", Sha256, msg, exp)
-}
-
-func TestRipemd160(t *testing.T) {
-	msg := []byte("abc")
-	exp, _ := hex.DecodeString("8eb208f7e05d987a9b044a8e98c6b087f15a0bfc")
-	checkhash(t, "Ripemd160", Ripemd160, msg, exp)
-}
-
 func BenchmarkSha3(b *testing.B) {
 	a := []byte("hello world")
 	amount := 1000000
@@ -170,7 +151,7 @@ func TestValidateSignatureValues(t *testing.T) {
 	minusOne := big.NewInt(-1)
 	one := common.Big1
 	zero := common.Big0
-	secp256k1nMinus1 := new(big.Int).Sub(secp256k1.N, common.Big1)
+	secp256k1nMinus1 := new(big.Int).Sub(secp256k1_N, common.Big1)
 
 	// correct v,r,s
 	check(true, 0, one, one)
@@ -197,9 +178,9 @@ func TestValidateSignatureValues(t *testing.T) {
 	// correct sig with max r,s
 	check(true, 0, secp256k1nMinus1, secp256k1nMinus1)
 	// correct v, combinations of incorrect r,s at upper limit
-	check(false, 0, secp256k1.N, secp256k1nMinus1)
+	check(false, 0, secp256k1_N, secp256k1nMinus1)
-	check(false, 0, secp256k1nMinus1, secp256k1.N)
+	check(false, 0, secp256k1nMinus1, secp256k1_N)
-	check(false, 0, secp256k1.N, secp256k1.N)
+	check(false, 0, secp256k1_N, secp256k1_N)
 
 	// current callers ensures r,s cannot be negative, but let's test for that too
 	// as crypto package could be used stand-alone
@@ -225,14 +206,13 @@ func checkAddr(t *testing.T, addr0, addr1 common.Address) {
 func TestPythonIntegration(t *testing.T) {
 	kh := "289c2857d4598e37fb9647507e47a309d6133539bf21a8b9cb6df88fd5232032"
 	k0, _ := HexToECDSA(kh)
-	k1 := FromECDSA(k0)
 
 	msg0 := Keccak256([]byte("foo"))
-	sig0, _ := secp256k1.Sign(msg0, k1)
+	sig0, _ := Sign(msg0, k0)
 
 	msg1 := common.FromHex("00000000000000000000000000000000")
-	sig1, _ := secp256k1.Sign(msg0, k1)
+	sig1, _ := Sign(msg0, k0)
 
-	fmt.Printf("msg: %x, privkey: %x sig: %x\n", msg0, k1, sig0)
+	t.Logf("msg: %x, privkey: %s sig: %x\n", msg0, kh, sig0)
-	fmt.Printf("msg: %x, privkey: %x sig: %x\n", msg1, k1, sig1)
+	t.Logf("msg: %x, privkey: %s sig: %x\n", msg1, kh, sig1)
 }

crypto/ecies/asn1.go

@@ -42,7 +42,7 @@ import (
 	"hash"
 	"math/big"
 
-	"github.com/expanse-org/go-expanse/crypto/secp256k1"
+	ethcrypto "github.com/expanse-org/go-expanse/crypto"
 )
 
 var (
@@ -120,7 +120,7 @@ func (curve secgNamedCurve) Equal(curve2 secgNamedCurve) bool {
 func namedCurveFromOID(curve secgNamedCurve) elliptic.Curve {
 	switch {
 	case curve.Equal(secgNamedCurveS256):
-		return secp256k1.S256()
+		return ethcrypto.S256()
 	case curve.Equal(secgNamedCurveP256):
 		return elliptic.P256()
 	case curve.Equal(secgNamedCurveP384):
@@ -139,7 +139,7 @@ func oidFromNamedCurve(curve elliptic.Curve) (secgNamedCurve, bool) {
 		return secgNamedCurveP384, true
 	case elliptic.P521():
 		return secgNamedCurveP521, true
-	case secp256k1.S256():
+	case ethcrypto.S256():
 		return secgNamedCurveS256, true
 	}
 

crypto/ecies/ecies_test.go

@@ -31,7 +31,6 @@ package ecies
 
 import (
 	"bytes"
-	"crypto/ecdsa"
 	"crypto/elliptic"
 	"crypto/rand"
 	"crypto/sha256"
@@ -42,7 +41,8 @@ import (
 	"math/big"
 	"testing"
 
-	"github.com/expanse-org/go-expanse/crypto/secp256k1"
+	"github.com/expanse-org/go-expanse/crypto"
+
 )
 
 var dumpEnc bool
@@ -150,7 +150,7 @@ func TestSharedKey(t *testing.T) {
 func TestSharedKeyPadding(t *testing.T) {
 	// sanity checks
 	prv0 := hexKey("1adf5c18167d96a1f9a0b1ef63be8aa27eaf6032c233b2b38f7850cf5b859fd9")
-	prv1 := hexKey("97a076fc7fcd9208240668e31c9abee952cbb6e375d1b8febc7499d6e16f1a")
+	prv1 := hexKey("0097a076fc7fcd9208240668e31c9abee952cbb6e375d1b8febc7499d6e16f1a")
 	x0, _ := new(big.Int).SetString("1a8ed022ff7aec59dc1b440446bdda5ff6bcb3509a8b109077282b361efffbd8", 16)
 	x1, _ := new(big.Int).SetString("6ab3ac374251f638d0abb3ef596d1dc67955b507c104e5f2009724812dc027b8", 16)
 	y0, _ := new(big.Int).SetString("e040bd480b1deccc3bc40bd5b1fdcb7bfd352500b477cb9471366dbd4493f923", 16)
@@ -354,7 +354,7 @@ func BenchmarkGenSharedKeyP256(b *testing.B) {
 
 // Benchmark the generation of S256 shared keys.
 func BenchmarkGenSharedKeyS256(b *testing.B) {
-	prv, err := GenerateKey(rand.Reader, secp256k1.S256(), nil)
+	prv, err := GenerateKey(rand.Reader, crypto.S256(), nil)
 	if err != nil {
 		fmt.Println(err.Error())
 		b.FailNow()
@@ -597,6 +597,29 @@ func TestBasicKeyValidation(t *testing.T) {
 	}
 }
 
+func TestBox(t *testing.T) {
+	prv1 := hexKey("4b50fa71f5c3eeb8fdc452224b2395af2fcc3d125e06c32c82e048c0559db03f")
+	prv2 := hexKey("d0b043b4c5d657670778242d82d68a29d25d7d711127d17b8e299f156dad361a")
+	pub2 := &prv2.PublicKey
+
+	message := []byte("Hello, world.")
+	ct, err := Encrypt(rand.Reader, pub2, message, nil, nil)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	pt, err := prv2.Decrypt(rand.Reader, ct, nil, nil)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if !bytes.Equal(pt, message) {
+		t.Fatal("ecies: plaintext doesn't match message")
+	}
+	if _, err = prv1.Decrypt(rand.Reader, ct, nil, nil); err == nil {
+		t.Fatal("ecies: encryption should not have succeeded")
+	}
+}
+
 // Verify GenerateShared against static values - useful when
 // debugging changes in underlying libs
 func TestSharedKeyStatic(t *testing.T) {
@@ -628,11 +651,10 @@ func TestSharedKeyStatic(t *testing.T) {
 	}
 }
 
-// TODO: remove after refactoring packages crypto and crypto/ecies
 func hexKey(prv string) *PrivateKey {
-	priv := new(ecdsa.PrivateKey)
+	key, err := crypto.HexToECDSA(prv)
-	priv.PublicKey.Curve = secp256k1.S256()
+	if err != nil {
-	priv.D, _ = new(big.Int).SetString(prv, 16)
+		panic(err)
-	priv.PublicKey.X, priv.PublicKey.Y = secp256k1.S256().ScalarBaseMult(priv.D.Bytes())
+	}
-	return ImportECDSA(priv)
+	return ImportECDSA(key)
 }

crypto/ecies/params.go

@@ -42,11 +42,11 @@ import (
 	"fmt"
 	"hash"
 
-	"github.com/expanse-org/go-expanse/crypto/secp256k1"
+	ethcrypto "github.com/expanse-org/go-expanse/crypto"
 )
 
 var (
-	DefaultCurve                  = secp256k1.S256()
+	DefaultCurve                  = ethcrypto.S256()
 	ErrUnsupportedECDHAlgorithm   = fmt.Errorf("ecies: unsupported ECDH algorithm")
 	ErrUnsupportedECIESParameters = fmt.Errorf("ecies: unsupported ECIES parameters")
 )
@@ -100,7 +100,7 @@ var (
 )
 
 var paramsFromCurve = map[elliptic.Curve]*ECIESParams{
-	secp256k1.S256(): ECIES_AES128_SHA256,
+	ethcrypto.S256(): ECIES_AES128_SHA256,
 	elliptic.P256():  ECIES_AES128_SHA256,
 	elliptic.P384():  ECIES_AES256_SHA384,
 	elliptic.P521():  ECIES_AES256_SHA512,

crypto/secp256k1/secp256.go

@@ -42,17 +42,9 @@ import (
 	"unsafe"
 )
 
-var (
+var context *C.secp256k1_context
-	context *C.secp256k1_context
-	N       *big.Int
-	HalfN   *big.Int
-)
 
 func init() {
-	N, _ = new(big.Int).SetString("fffffffffffffffffffffffffffffffebaaedce6af48a03bbfd25e8cd0364141", 16)
-	// N / 2 == 57896044618658097711785492504343953926418782139537452191302581570759080747168
-	HalfN, _ = new(big.Int).SetString("7fffffffffffffffffffffffffffffff5d576e7357a4501ddfe92f46681b20a0", 16)
-
 	// around 20 ms on a modern CPU.
 	context = C.secp256k1_context_create_sign_verify()
 	C.secp256k1_context_set_illegal_callback(context, C.callbackFunc(C.secp256k1GoPanicIllegal), nil)

crypto/signature_cgo.go

@@ -0,0 +1,64 @@
+// Copyright 2016 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/>.
+
+// +build !nacl,!js,!nocgo
+
+package crypto
+
+import (
+	"crypto/ecdsa"
+	"crypto/elliptic"
+	"fmt"
+
+	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/crypto/secp256k1"
+)
+
+func Ecrecover(hash, sig []byte) ([]byte, error) {
+	return secp256k1.RecoverPubkey(hash, sig)
+}
+
+func SigToPub(hash, sig []byte) (*ecdsa.PublicKey, error) {
+	s, err := Ecrecover(hash, sig)
+	if err != nil {
+		return nil, err
+	}
+
+	x, y := elliptic.Unmarshal(S256(), s)
+	return &ecdsa.PublicKey{Curve: S256(), X: x, Y: y}, nil
+}
+
+// Sign calculates an ECDSA signature.
+//
+// This function is susceptible to chosen plaintext attacks that can leak
+// information about the private key that is used for signing. Callers must
+// be aware that the given hash cannot be chosen by an adversery. Common
+// solution is to hash any input before calculating the signature.
+//
+// The produced signature is in the [R || S || V] format where V is 0 or 1.
+func Sign(hash []byte, prv *ecdsa.PrivateKey) (sig []byte, err error) {
+	if len(hash) != 32 {
+		return nil, fmt.Errorf("hash is required to be exactly 32 bytes (%d)", len(hash))
+	}
+	seckey := common.LeftPadBytes(prv.D.Bytes(), prv.Params().BitSize/8)
+	defer zeroBytes(seckey)
+	return secp256k1.Sign(hash, seckey)
+}
+
+// S256 returns an instance of the secp256k1 curve.
+func S256() elliptic.Curve {
+	return secp256k1.S256()
+}

crypto/signature_nocgo.go

@@ -0,0 +1,77 @@
+// Copyright 2016 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/>.
+
+// +build nacl js nocgo
+
+package crypto
+
+import (
+	"crypto/ecdsa"
+	"crypto/elliptic"
+	"fmt"
+
+	"github.com/btcsuite/btcd/btcec"
+)
+
+func Ecrecover(hash, sig []byte) ([]byte, error) {
+	pub, err := SigToPub(hash, sig)
+	if err != nil {
+		return nil, err
+	}
+	bytes := (*btcec.PublicKey)(pub).SerializeUncompressed()
+	return bytes, err
+}
+
+func SigToPub(hash, sig []byte) (*ecdsa.PublicKey, error) {
+	// Convert to btcec input format with 'recovery id' v at the beginning.
+	btcsig := make([]byte, 65)
+	btcsig[0] = sig[64] + 27
+	copy(btcsig[1:], sig)
+
+	pub, _, err := btcec.RecoverCompact(btcec.S256(), btcsig, hash)
+	return (*ecdsa.PublicKey)(pub), err
+}
+
+// Sign calculates an ECDSA signature.
+//
+// This function is susceptible to chosen plaintext attacks that can leak
+// information about the private key that is used for signing. Callers must
+// be aware that the given hash cannot be chosen by an adversery. Common
+// solution is to hash any input before calculating the signature.
+//
+// The produced signature is in the [R || S || V] format where V is 0 or 1.
+func Sign(hash []byte, prv *ecdsa.PrivateKey) ([]byte, error) {
+	if len(hash) != 32 {
+		return nil, fmt.Errorf("hash is required to be exactly 32 bytes (%d)", len(hash))
+	}
+	if prv.Curve != btcec.S256() {
+		return nil, fmt.Errorf("private key curve is not secp256k1")
+	}
+	sig, err := btcec.SignCompact(btcec.S256(), (*btcec.PrivateKey)(prv), hash, false)
+	if err != nil {
+		return nil, err
+	}
+	// Convert to Ethereum signature format with 'recovery id' v at the end.
+	v := sig[0] - 27
+	copy(sig, sig[1:])
+	sig[64] = v
+	return sig, nil
+}
+
+// S256 returns an instance of the secp256k1 curve.
+func S256() elliptic.Curve {
+	return btcec.S256()
+}

crypto/signature_test.go

@@ -14,18 +14,23 @@
 // 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 discv5
+package crypto
 
 import (
-	//"github.com/btcsuite/btcd/btcec"
+	"bytes"
-	"github.com/expanse-org/go-expanse/crypto/secp256k1"
+	"encoding/hex"
+	"testing"
 )
 
-func S256() *secp256k1.BitCurve {
+func TestRecoverSanity(t *testing.T) {
-	return secp256k1.S256()
+	msg, _ := hex.DecodeString("ce0677bb30baa8cf067c88db9811f4333d131bf8bcf12fe7065d211dce971008")
+	sig, _ := hex.DecodeString("90f27b8b488db00b00606796d2987f6a5f59ae62ea05effe84fef5b8b0e549984a691139ad57a3f0b906637673aa2f63d1f55cb1a69199d4009eea23ceaddc9301")
+	pubkey1, _ := hex.DecodeString("04e32df42865e97135acfb65f3bae71bdc86f4d49150ad6a440b6f15878109880a0a2b2667f7e725ceea70c673093bf67663e0312623c8e091b13cf2c0f11ef652")
+	pubkey2, err := Ecrecover(msg, sig)
+	if err != nil {
+		t.Fatalf("recover error: %s", err)
+	}
+	if !bytes.Equal(pubkey1, pubkey2) {
+		t.Errorf("pubkey mismatch: want: %x have: %x", pubkey1, pubkey2)
+	}
 }
-
-// This version should be used for NaCl compilation
-/*func S256() *btcec.KoblitzCurve {
-	return S256()
-}*/

p2p/discover/node.go

@@ -259,7 +259,7 @@ func PubkeyID(pub *ecdsa.PublicKey) NodeID {
 // Pubkey returns the public key represented by the node ID.
 // It returns an error if the ID is not a point on the curve.
 func (id NodeID) Pubkey() (*ecdsa.PublicKey, error) {
-	p := &ecdsa.PublicKey{Curve: secp256k1.S256(), X: new(big.Int), Y: new(big.Int)}
+	p := &ecdsa.PublicKey{Curve: crypto.S256(), X: new(big.Int), Y: new(big.Int)}
 	half := len(id) / 2
 	p.X.SetBytes(id[:half])
 	p.Y.SetBytes(id[half:])

p2p/discv5/node.go

@@ -297,7 +297,7 @@ func PubkeyID(pub *ecdsa.PublicKey) NodeID {
 // Pubkey returns the public key represented by the node ID.
 // It returns an error if the ID is not a point on the curve.
 func (id NodeID) Pubkey() (*ecdsa.PublicKey, error) {
-	p := &ecdsa.PublicKey{Curve: S256(), X: new(big.Int), Y: new(big.Int)}
+	p := &ecdsa.PublicKey{Curve: crypto.S256(), X: new(big.Int), Y: new(big.Int)}
 	half := len(id) / 2
 	p.X.SetBytes(id[:half])
 	p.Y.SetBytes(id[half:])

p2p/rlpx.go

@@ -303,7 +303,7 @@ func (h *encHandshake) makeAuthMsg(prv *ecdsa.PrivateKey, token []byte) (*authMs
 		return nil, err
 	}
 	// Generate random keypair to for ECDH.
-	h.randomPrivKey, err = ecies.GenerateKey(rand.Reader, secp256k1.S256(), nil)
+	h.randomPrivKey, err = ecies.GenerateKey(rand.Reader, crypto.S256(), nil)
 	if err != nil {
 		return nil, err
 	}
@@ -381,7 +381,7 @@ func (h *encHandshake) handleAuthMsg(msg *authMsgV4, prv *ecdsa.PrivateKey) erro
 	// Generate random keypair for ECDH.
 	// If a private key is already set, use it instead of generating one (for testing).
 	if h.randomPrivKey == nil {
-		h.randomPrivKey, err = ecies.GenerateKey(rand.Reader, secp256k1.S256(), nil)
+		h.randomPrivKey, err = ecies.GenerateKey(rand.Reader, crypto.S256(), nil)
 		if err != nil {
 			return err
 		}

params/version.go

@@ -20,8 +20,8 @@ import "fmt"
 
 const (
 	VersionMajor = 1          // Major version component of the current release
-	VersionMinor = 5          // Minor version component of the current release
+	VersionMinor = 6          // Minor version component of the current release
-	VersionPatch = 10         // Patch version component of the current release
+	VersionPatch = 0          // Patch version component of the current release
 	VersionMeta  = "unstable" // Version metadata to append to the version string
 )
 

tests/block_test_util.go

@@ -177,6 +177,7 @@ func runBlockTest(homesteadBlock, daoForkBlock, gasPriceFork *big.Int, test *Blo
 	if err != nil {
 		return err
 	}
+	defer chain.Stop()
 
 	//vm.Debug = true
 	validBlocks, err := test.TryBlocksInsert(chain)

vendor/github.com/btcsuite/btcd/LICENSE

@@ -0,0 +1,16 @@
+ISC License
+
+Copyright (c) 2013-2017 The btcsuite developers
+Copyright (c) 2015-2016 The Decred developers
+
+Permission to use, copy, modify, and distribute this software for any
+purpose with or without fee is hereby granted, provided that the above
+copyright notice and this permission notice appear in all copies.
+
+THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.

vendor/github.com/btcsuite/btcd/btcec/README.md

@@ -0,0 +1,74 @@
+btcec
+=====
+
+[![Build Status](https://travis-ci.org/btcsuite/btcd.png?branch=master)]
+(https://travis-ci.org/btcsuite/btcec) [![ISC License]
+(http://img.shields.io/badge/license-ISC-blue.svg)](http://copyfree.org)
+[![GoDoc](https://godoc.org/github.com/btcsuite/btcd/btcec?status.png)]
+(http://godoc.org/github.com/btcsuite/btcd/btcec)
+
+Package btcec implements elliptic curve cryptography needed for working with
+Bitcoin (secp256k1 only for now). It is designed so that it may be used with the
+standard crypto/ecdsa packages provided with go.  A comprehensive suite of test
+is provided to ensure proper functionality.  Package btcec was originally based
+on work from ThePiachu which is licensed under the same terms as Go, but it has
+signficantly diverged since then.  The btcsuite developers original is licensed
+under the liberal ISC license.
+
+Although this package was primarily written for btcd, it has intentionally been
+designed so it can be used as a standalone package for any projects needing to
+use secp256k1 elliptic curve cryptography.
+
+## Installation and Updating
+
+```bash
+$ go get -u github.com/btcsuite/btcd/btcec
+```
+
+## Examples
+
+* [Sign Message]
+  (http://godoc.org/github.com/btcsuite/btcd/btcec#example-package--SignMessage)  
+  Demonstrates signing a message with a secp256k1 private key that is first
+  parsed form raw bytes and serializing the generated signature.
+
+* [Verify Signature]
+  (http://godoc.org/github.com/btcsuite/btcd/btcec#example-package--VerifySignature)  
+  Demonstrates verifying a secp256k1 signature against a public key that is
+  first parsed from raw bytes.  The signature is also parsed from raw bytes.
+
+* [Encryption]
+  (http://godoc.org/github.com/btcsuite/btcd/btcec#example-package--EncryptMessage)
+  Demonstrates encrypting a message for a public key that is first parsed from
+  raw bytes, then decrypting it using the corresponding private key.
+
+* [Decryption]
+  (http://godoc.org/github.com/btcsuite/btcd/btcec#example-package--DecryptMessage)
+  Demonstrates decrypting a message using a private key that is first parsed
+  from raw bytes.
+
+## GPG Verification Key
+
+All official release tags are signed by Conformal so users can ensure the code
+has not been tampered with and is coming from the btcsuite developers.  To
+verify the signature perform the following:
+
+- Download the public key from the Conformal website at
+  https://opensource.conformal.com/GIT-GPG-KEY-conformal.txt
+
+- Import the public key into your GPG keyring:
+  ```bash
+  gpg --import GIT-GPG-KEY-conformal.txt
+  ```
+
+- Verify the release tag with the following command where `TAG_NAME` is a
+  placeholder for the specific tag:
+  ```bash
+  git tag -v TAG_NAME
+  ```
+
+## License
+
+Package btcec is licensed under the [copyfree](http://copyfree.org) ISC License
+except for btcec.go and btcec_test.go which is under the same license as Go.
+

vendor/github.com/btcsuite/btcd/btcec/btcec.go

@@ -0,0 +1,956 @@
+// Copyright 2010 The Go Authors. All rights reserved.
+// Copyright 2011 ThePiachu. All rights reserved.
+// Copyright 2013-2014 The btcsuite developers
+// Use of this source code is governed by an ISC
+// license that can be found in the LICENSE file.
+
+package btcec
+
+// References:
+//   [SECG]: Recommended Elliptic Curve Domain Parameters
+//     http://www.secg.org/sec2-v2.pdf
+//
+//   [GECC]: Guide to Elliptic Curve Cryptography (Hankerson, Menezes, Vanstone)
+
+// This package operates, internally, on Jacobian coordinates. For a given
+// (x, y) position on the curve, the Jacobian coordinates are (x1, y1, z1)
+// where x = x1/z1² and y = y1/z1³. The greatest speedups come when the whole
+// calculation can be performed within the transform (as in ScalarMult and
+// ScalarBaseMult). But even for Add and Double, it's faster to apply and
+// reverse the transform than to operate in affine coordinates.
+
+import (
+	"crypto/elliptic"
+	"math/big"
+	"sync"
+)
+
+var (
+	// fieldOne is simply the integer 1 in field representation.  It is
+	// used to avoid needing to create it multiple times during the internal
+	// arithmetic.
+	fieldOne = new(fieldVal).SetInt(1)
+)
+
+// KoblitzCurve supports a koblitz curve implementation that fits the ECC Curve
+// interface from crypto/elliptic.
+type KoblitzCurve struct {
+	*elliptic.CurveParams
+	q *big.Int
+	H int // cofactor of the curve.
+
+	// byteSize is simply the bit size / 8 and is provided for convenience
+	// since it is calculated repeatedly.
+	byteSize int
+
+	// bytePoints
+	bytePoints *[32][256][3]fieldVal
+
+	// The next 6 values are used specifically for endomorphism
+	// optimizations in ScalarMult.
+
+	// lambda must fulfill lambda^3 = 1 mod N where N is the order of G.
+	lambda *big.Int
+
+	// beta must fulfill beta^3 = 1 mod P where P is the prime field of the
+	// curve.
+	beta *fieldVal
+
+	// See the EndomorphismVectors in gensecp256k1.go to see how these are
+	// derived.
+	a1 *big.Int
+	b1 *big.Int
+	a2 *big.Int
+	b2 *big.Int
+}
+
+// Params returns the parameters for the curve.
+func (curve *KoblitzCurve) Params() *elliptic.CurveParams {
+	return curve.CurveParams
+}
+
+// bigAffineToField takes an affine point (x, y) as big integers and converts
+// it to an affine point as field values.
+func (curve *KoblitzCurve) bigAffineToField(x, y *big.Int) (*fieldVal, *fieldVal) {
+	x3, y3 := new(fieldVal), new(fieldVal)
+	x3.SetByteSlice(x.Bytes())
+	y3.SetByteSlice(y.Bytes())
+
+	return x3, y3
+}
+
+// fieldJacobianToBigAffine takes a Jacobian point (x, y, z) as field values and
+// converts it to an affine point as big integers.
+func (curve *KoblitzCurve) fieldJacobianToBigAffine(x, y, z *fieldVal) (*big.Int, *big.Int) {
+	// Inversions are expensive and both point addition and point doubling
+	// are faster when working with points that have a z value of one.  So,
+	// if the point needs to be converted to affine, go ahead and normalize
+	// the point itself at the same time as the calculation is the same.
+	var zInv, tempZ fieldVal
+	zInv.Set(z).Inverse()   // zInv = Z^-1
+	tempZ.SquareVal(&zInv)  // tempZ = Z^-2
+	x.Mul(&tempZ)           // X = X/Z^2 (mag: 1)
+	y.Mul(tempZ.Mul(&zInv)) // Y = Y/Z^3 (mag: 1)
+	z.SetInt(1)             // Z = 1 (mag: 1)
+
+	// Normalize the x and y values.
+	x.Normalize()
+	y.Normalize()
+
+	// Convert the field values for the now affine point to big.Ints.
+	x3, y3 := new(big.Int), new(big.Int)
+	x3.SetBytes(x.Bytes()[:])
+	y3.SetBytes(y.Bytes()[:])
+	return x3, y3
+}
+
+// IsOnCurve returns boolean if the point (x,y) is on the curve.
+// Part of the elliptic.Curve interface. This function differs from the
+// crypto/elliptic algorithm since a = 0 not -3.
+func (curve *KoblitzCurve) IsOnCurve(x, y *big.Int) bool {
+	// Convert big ints to field values for faster arithmetic.
+	fx, fy := curve.bigAffineToField(x, y)
+
+	// Elliptic curve equation for secp256k1 is: y^2 = x^3 + 7
+	y2 := new(fieldVal).SquareVal(fy).Normalize()
+	result := new(fieldVal).SquareVal(fx).Mul(fx).AddInt(7).Normalize()
+	return y2.Equals(result)
+}
+
+// addZ1AndZ2EqualsOne adds two Jacobian points that are already known to have
+// z values of 1 and stores the result in (x3, y3, z3).  That is to say
+// (x1, y1, 1) + (x2, y2, 1) = (x3, y3, z3).  It performs faster addition than
+// the generic add routine since less arithmetic is needed due to the ability to
+// avoid the z value multiplications.
+func (curve *KoblitzCurve) addZ1AndZ2EqualsOne(x1, y1, z1, x2, y2, x3, y3, z3 *fieldVal) {
+	// To compute the point addition efficiently, this implementation splits
+	// the equation into intermediate elements which are used to minimize
+	// the number of field multiplications using the method shown at:
+	// http://hyperelliptic.org/EFD/g1p/auto-shortw-jacobian-0.html#addition-mmadd-2007-bl
+	//
+	// In particular it performs the calculations using the following:
+	// H = X2-X1, HH = H^2, I = 4*HH, J = H*I, r = 2*(Y2-Y1), V = X1*I
+	// X3 = r^2-J-2*V, Y3 = r*(V-X3)-2*Y1*J, Z3 = 2*H
+	//
+	// This results in a cost of 4 field multiplications, 2 field squarings,
+	// 6 field additions, and 5 integer multiplications.
+
+	// When the x coordinates are the same for two points on the curve, the
+	// y coordinates either must be the same, in which case it is point
+	// doubling, or they are opposite and the result is the point at
+	// infinity per the group law for elliptic curve cryptography.
+	x1.Normalize()
+	y1.Normalize()
+	x2.Normalize()
+	y2.Normalize()
+	if x1.Equals(x2) {
+		if y1.Equals(y2) {
+			// Since x1 == x2 and y1 == y2, point doubling must be
+			// done, otherwise the addition would end up dividing
+			// by zero.
+			curve.doubleJacobian(x1, y1, z1, x3, y3, z3)
+			return
+		}
+
+		// Since x1 == x2 and y1 == -y2, the sum is the point at
+		// infinity per the group law.
+		x3.SetInt(0)
+		y3.SetInt(0)
+		z3.SetInt(0)
+		return
+	}
+
+	// Calculate X3, Y3, and Z3 according to the intermediate elements
+	// breakdown above.
+	var h, i, j, r, v fieldVal
+	var negJ, neg2V, negX3 fieldVal
+	h.Set(x1).Negate(1).Add(x2)                // H = X2-X1 (mag: 3)
+	i.SquareVal(&h).MulInt(4)                  // I = 4*H^2 (mag: 4)
+	j.Mul2(&h, &i)                             // J = H*I (mag: 1)
+	r.Set(y1).Negate(1).Add(y2).MulInt(2)      // r = 2*(Y2-Y1) (mag: 6)
+	v.Mul2(x1, &i)                             // V = X1*I (mag: 1)
+	negJ.Set(&j).Negate(1)                     // negJ = -J (mag: 2)
+	neg2V.Set(&v).MulInt(2).Negate(2)          // neg2V = -(2*V) (mag: 3)
+	x3.Set(&r).Square().Add(&negJ).Add(&neg2V) // X3 = r^2-J-2*V (mag: 6)
+	negX3.Set(x3).Negate(6)                    // negX3 = -X3 (mag: 7)
+	j.Mul(y1).MulInt(2).Negate(2)              // J = -(2*Y1*J) (mag: 3)
+	y3.Set(&v).Add(&negX3).Mul(&r).Add(&j)     // Y3 = r*(V-X3)-2*Y1*J (mag: 4)
+	z3.Set(&h).MulInt(2)                       // Z3 = 2*H (mag: 6)
+
+	// Normalize the resulting field values to a magnitude of 1 as needed.
+	x3.Normalize()
+	y3.Normalize()
+	z3.Normalize()
+}
+
+// addZ1EqualsZ2 adds two Jacobian points that are already known to have the
+// same z value and stores the result in (x3, y3, z3).  That is to say
+// (x1, y1, z1) + (x2, y2, z1) = (x3, y3, z3).  It performs faster addition than
+// the generic add routine since less arithmetic is needed due to the known
+// equivalence.
+func (curve *KoblitzCurve) addZ1EqualsZ2(x1, y1, z1, x2, y2, x3, y3, z3 *fieldVal) {
+	// To compute the point addition efficiently, this implementation splits
+	// the equation into intermediate elements which are used to minimize
+	// the number of field multiplications using a slightly modified version
+	// of the method shown at:
+	// http://hyperelliptic.org/EFD/g1p/auto-shortw-jacobian-0.html#addition-mmadd-2007-bl
+	//
+	// In particular it performs the calculations using the following:
+	// A = X2-X1, B = A^2, C=Y2-Y1, D = C^2, E = X1*B, F = X2*B
+	// X3 = D-E-F, Y3 = C*(E-X3)-Y1*(F-E), Z3 = Z1*A
+	//
+	// This results in a cost of 5 field multiplications, 2 field squarings,
+	// 9 field additions, and 0 integer multiplications.
+
+	// When the x coordinates are the same for two points on the curve, the
+	// y coordinates either must be the same, in which case it is point
+	// doubling, or they are opposite and the result is the point at
+	// infinity per the group law for elliptic curve cryptography.
+	x1.Normalize()
+	y1.Normalize()
+	x2.Normalize()
+	y2.Normalize()
+	if x1.Equals(x2) {
+		if y1.Equals(y2) {
+			// Since x1 == x2 and y1 == y2, point doubling must be
+			// done, otherwise the addition would end up dividing
+			// by zero.
+			curve.doubleJacobian(x1, y1, z1, x3, y3, z3)
+			return
+		}
+
+		// Since x1 == x2 and y1 == -y2, the sum is the point at
+		// infinity per the group law.
+		x3.SetInt(0)
+		y3.SetInt(0)
+		z3.SetInt(0)
+		return
+	}
+
+	// Calculate X3, Y3, and Z3 according to the intermediate elements
+	// breakdown above.
+	var a, b, c, d, e, f fieldVal
+	var negX1, negY1, negE, negX3 fieldVal
+	negX1.Set(x1).Negate(1)                // negX1 = -X1 (mag: 2)
+	negY1.Set(y1).Negate(1)                // negY1 = -Y1 (mag: 2)
+	a.Set(&negX1).Add(x2)                  // A = X2-X1 (mag: 3)
+	b.SquareVal(&a)                        // B = A^2 (mag: 1)
+	c.Set(&negY1).Add(y2)                  // C = Y2-Y1 (mag: 3)
+	d.SquareVal(&c)                        // D = C^2 (mag: 1)
+	e.Mul2(x1, &b)                         // E = X1*B (mag: 1)
+	negE.Set(&e).Negate(1)                 // negE = -E (mag: 2)
+	f.Mul2(x2, &b)                         // F = X2*B (mag: 1)
+	x3.Add2(&e, &f).Negate(3).Add(&d)      // X3 = D-E-F (mag: 5)
+	negX3.Set(x3).Negate(5).Normalize()    // negX3 = -X3 (mag: 1)
+	y3.Set(y1).Mul(f.Add(&negE)).Negate(3) // Y3 = -(Y1*(F-E)) (mag: 4)
+	y3.Add(e.Add(&negX3).Mul(&c))          // Y3 = C*(E-X3)+Y3 (mag: 5)
+	z3.Mul2(z1, &a)                        // Z3 = Z1*A (mag: 1)
+
+	// Normalize the resulting field values to a magnitude of 1 as needed.
+	x3.Normalize()
+	y3.Normalize()
+}
+
+// addZ2EqualsOne adds two Jacobian points when the second point is already
+// known to have a z value of 1 (and the z value for the first point is not 1)
+// and stores the result in (x3, y3, z3).  That is to say (x1, y1, z1) +
+// (x2, y2, 1) = (x3, y3, z3).  It performs faster addition than the generic
+// add routine since less arithmetic is needed due to the ability to avoid
+// multiplications by the second point's z value.
+func (curve *KoblitzCurve) addZ2EqualsOne(x1, y1, z1, x2, y2, x3, y3, z3 *fieldVal) {
+	// To compute the point addition efficiently, this implementation splits
+	// the equation into intermediate elements which are used to minimize
+	// the number of field multiplications using the method shown at:
+	// http://hyperelliptic.org/EFD/g1p/auto-shortw-jacobian-0.html#addition-madd-2007-bl
+	//
+	// In particular it performs the calculations using the following:
+	// Z1Z1 = Z1^2, U2 = X2*Z1Z1, S2 = Y2*Z1*Z1Z1, H = U2-X1, HH = H^2,
+	// I = 4*HH, J = H*I, r = 2*(S2-Y1), V = X1*I
+	// X3 = r^2-J-2*V, Y3 = r*(V-X3)-2*Y1*J, Z3 = (Z1+H)^2-Z1Z1-HH
+	//
+	// This results in a cost of 7 field multiplications, 4 field squarings,
+	// 9 field additions, and 4 integer multiplications.
+
+	// When the x coordinates are the same for two points on the curve, the
+	// y coordinates either must be the same, in which case it is point
+	// doubling, or they are opposite and the result is the point at
+	// infinity per the group law for elliptic curve cryptography.  Since
+	// any number of Jacobian coordinates can represent the same affine
+	// point, the x and y values need to be converted to like terms.  Due to
+	// the assumption made for this function that the second point has a z
+	// value of 1 (z2=1), the first point is already "converted".
+	var z1z1, u2, s2 fieldVal
+	x1.Normalize()
+	y1.Normalize()
+	z1z1.SquareVal(z1)                        // Z1Z1 = Z1^2 (mag: 1)
+	u2.Set(x2).Mul(&z1z1).Normalize()         // U2 = X2*Z1Z1 (mag: 1)
+	s2.Set(y2).Mul(&z1z1).Mul(z1).Normalize() // S2 = Y2*Z1*Z1Z1 (mag: 1)
+	if x1.Equals(&u2) {
+		if y1.Equals(&s2) {
+			// Since x1 == x2 and y1 == y2, point doubling must be
+			// done, otherwise the addition would end up dividing
+			// by zero.
+			curve.doubleJacobian(x1, y1, z1, x3, y3, z3)
+			return
+		}
+
+		// Since x1 == x2 and y1 == -y2, the sum is the point at
+		// infinity per the group law.
+		x3.SetInt(0)
+		y3.SetInt(0)
+		z3.SetInt(0)
+		return
+	}
+
+	// Calculate X3, Y3, and Z3 according to the intermediate elements
+	// breakdown above.
+	var h, hh, i, j, r, rr, v fieldVal
+	var negX1, negY1, negX3 fieldVal
+	negX1.Set(x1).Negate(1)                // negX1 = -X1 (mag: 2)
+	h.Add2(&u2, &negX1)                    // H = U2-X1 (mag: 3)
+	hh.SquareVal(&h)                       // HH = H^2 (mag: 1)
+	i.Set(&hh).MulInt(4)                   // I = 4 * HH (mag: 4)
+	j.Mul2(&h, &i)                         // J = H*I (mag: 1)
+	negY1.Set(y1).Negate(1)                // negY1 = -Y1 (mag: 2)
+	r.Set(&s2).Add(&negY1).MulInt(2)       // r = 2*(S2-Y1) (mag: 6)
+	rr.SquareVal(&r)                       // rr = r^2 (mag: 1)
+	v.Mul2(x1, &i)                         // V = X1*I (mag: 1)
+	x3.Set(&v).MulInt(2).Add(&j).Negate(3) // X3 = -(J+2*V) (mag: 4)
+	x3.Add(&rr)                            // X3 = r^2+X3 (mag: 5)
+	negX3.Set(x3).Negate(5)                // negX3 = -X3 (mag: 6)
+	y3.Set(y1).Mul(&j).MulInt(2).Negate(2) // Y3 = -(2*Y1*J) (mag: 3)
+	y3.Add(v.Add(&negX3).Mul(&r))          // Y3 = r*(V-X3)+Y3 (mag: 4)
+	z3.Add2(z1, &h).Square()               // Z3 = (Z1+H)^2 (mag: 1)
+	z3.Add(z1z1.Add(&hh).Negate(2))        // Z3 = Z3-(Z1Z1+HH) (mag: 4)
+
+	// Normalize the resulting field values to a magnitude of 1 as needed.
+	x3.Normalize()
+	y3.Normalize()
+	z3.Normalize()
+}
+
+// addGeneric adds two Jacobian points (x1, y1, z1) and (x2, y2, z2) without any
+// assumptions about the z values of the two points and stores the result in
+// (x3, y3, z3).  That is to say (x1, y1, z1) + (x2, y2, z2) = (x3, y3, z3).  It
+// is the slowest of the add routines due to requiring the most arithmetic.
+func (curve *KoblitzCurve) addGeneric(x1, y1, z1, x2, y2, z2, x3, y3, z3 *fieldVal) {
+	// To compute the point addition efficiently, this implementation splits
+	// the equation into intermediate elements which are used to minimize
+	// the number of field multiplications using the method shown at:
+	// http://hyperelliptic.org/EFD/g1p/auto-shortw-jacobian-0.html#addition-add-2007-bl
+	//
+	// In particular it performs the calculations using the following:
+	// Z1Z1 = Z1^2, Z2Z2 = Z2^2, U1 = X1*Z2Z2, U2 = X2*Z1Z1, S1 = Y1*Z2*Z2Z2
+	// S2 = Y2*Z1*Z1Z1, H = U2-U1, I = (2*H)^2, J = H*I, r = 2*(S2-S1)
+	// V = U1*I
+	// X3 = r^2-J-2*V, Y3 = r*(V-X3)-2*S1*J, Z3 = ((Z1+Z2)^2-Z1Z1-Z2Z2)*H
+	//
+	// This results in a cost of 11 field multiplications, 5 field squarings,
+	// 9 field additions, and 4 integer multiplications.
+
+	// When the x coordinates are the same for two points on the curve, the
+	// y coordinates either must be the same, in which case it is point
+	// doubling, or they are opposite and the result is the point at
+	// infinity.  Since any number of Jacobian coordinates can represent the
+	// same affine point, the x and y values need to be converted to like
+	// terms.
+	var z1z1, z2z2, u1, u2, s1, s2 fieldVal
+	z1z1.SquareVal(z1)                        // Z1Z1 = Z1^2 (mag: 1)
+	z2z2.SquareVal(z2)                        // Z2Z2 = Z2^2 (mag: 1)
+	u1.Set(x1).Mul(&z2z2).Normalize()         // U1 = X1*Z2Z2 (mag: 1)
+	u2.Set(x2).Mul(&z1z1).Normalize()         // U2 = X2*Z1Z1 (mag: 1)
+	s1.Set(y1).Mul(&z2z2).Mul(z2).Normalize() // S1 = Y1*Z2*Z2Z2 (mag: 1)
+	s2.Set(y2).Mul(&z1z1).Mul(z1).Normalize() // S2 = Y2*Z1*Z1Z1 (mag: 1)
+	if u1.Equals(&u2) {
+		if s1.Equals(&s2) {
+			// Since x1 == x2 and y1 == y2, point doubling must be
+			// done, otherwise the addition would end up dividing
+			// by zero.
+			curve.doubleJacobian(x1, y1, z1, x3, y3, z3)
+			return
+		}
+
+		// Since x1 == x2 and y1 == -y2, the sum is the point at
+		// infinity per the group law.
+		x3.SetInt(0)
+		y3.SetInt(0)
+		z3.SetInt(0)
+		return
+	}
+
+	// Calculate X3, Y3, and Z3 according to the intermediate elements
+	// breakdown above.
+	var h, i, j, r, rr, v fieldVal
+	var negU1, negS1, negX3 fieldVal
+	negU1.Set(&u1).Negate(1)               // negU1 = -U1 (mag: 2)
+	h.Add2(&u2, &negU1)                    // H = U2-U1 (mag: 3)
+	i.Set(&h).MulInt(2).Square()           // I = (2*H)^2 (mag: 2)
+	j.Mul2(&h, &i)                         // J = H*I (mag: 1)
+	negS1.Set(&s1).Negate(1)               // negS1 = -S1 (mag: 2)
+	r.Set(&s2).Add(&negS1).MulInt(2)       // r = 2*(S2-S1) (mag: 6)
+	rr.SquareVal(&r)                       // rr = r^2 (mag: 1)
+	v.Mul2(&u1, &i)                        // V = U1*I (mag: 1)
+	x3.Set(&v).MulInt(2).Add(&j).Negate(3) // X3 = -(J+2*V) (mag: 4)
+	x3.Add(&rr)                            // X3 = r^2+X3 (mag: 5)
+	negX3.Set(x3).Negate(5)                // negX3 = -X3 (mag: 6)
+	y3.Mul2(&s1, &j).MulInt(2).Negate(2)   // Y3 = -(2*S1*J) (mag: 3)
+	y3.Add(v.Add(&negX3).Mul(&r))          // Y3 = r*(V-X3)+Y3 (mag: 4)
+	z3.Add2(z1, z2).Square()               // Z3 = (Z1+Z2)^2 (mag: 1)
+	z3.Add(z1z1.Add(&z2z2).Negate(2))      // Z3 = Z3-(Z1Z1+Z2Z2) (mag: 4)
+	z3.Mul(&h)                             // Z3 = Z3*H (mag: 1)
+
+	// Normalize the resulting field values to a magnitude of 1 as needed.
+	x3.Normalize()
+	y3.Normalize()
+}
+
+// addJacobian adds the passed Jacobian points (x1, y1, z1) and (x2, y2, z2)
+// together and stores the result in (x3, y3, z3).
+func (curve *KoblitzCurve) addJacobian(x1, y1, z1, x2, y2, z2, x3, y3, z3 *fieldVal) {
+	// A point at infinity is the identity according to the group law for
+	// elliptic curve cryptography.  Thus, ∞ + P = P and P + ∞ = P.
+	if (x1.IsZero() && y1.IsZero()) || z1.IsZero() {
+		x3.Set(x2)
+		y3.Set(y2)
+		z3.Set(z2)
+		return
+	}
+	if (x2.IsZero() && y2.IsZero()) || z2.IsZero() {
+		x3.Set(x1)
+		y3.Set(y1)
+		z3.Set(z1)
+		return
+	}
+
+	// Faster point addition can be achieved when certain assumptions are
+	// met.  For example, when both points have the same z value, arithmetic
+	// on the z values can be avoided.  This section thus checks for these
+	// conditions and calls an appropriate add function which is accelerated
+	// by using those assumptions.
+	z1.Normalize()
+	z2.Normalize()
+	isZ1One := z1.Equals(fieldOne)
+	isZ2One := z2.Equals(fieldOne)
+	switch {
+	case isZ1One && isZ2One:
+		curve.addZ1AndZ2EqualsOne(x1, y1, z1, x2, y2, x3, y3, z3)
+		return
+	case z1.Equals(z2):
+		curve.addZ1EqualsZ2(x1, y1, z1, x2, y2, x3, y3, z3)
+		return
+	case isZ2One:
+		curve.addZ2EqualsOne(x1, y1, z1, x2, y2, x3, y3, z3)
+		return
+	}
+
+	// None of the above assumptions are true, so fall back to generic
+	// point addition.
+	curve.addGeneric(x1, y1, z1, x2, y2, z2, x3, y3, z3)
+}
+
+// Add returns the sum of (x1,y1) and (x2,y2). Part of the elliptic.Curve
+// interface.
+func (curve *KoblitzCurve) Add(x1, y1, x2, y2 *big.Int) (*big.Int, *big.Int) {
+	// A point at infinity is the identity according to the group law for
+	// elliptic curve cryptography.  Thus, ∞ + P = P and P + ∞ = P.
+	if x1.Sign() == 0 && y1.Sign() == 0 {
+		return x2, y2
+	}
+	if x2.Sign() == 0 && y2.Sign() == 0 {
+		return x1, y1
+	}
+
+	// Convert the affine coordinates from big integers to field values
+	// and do the point addition in Jacobian projective space.
+	fx1, fy1 := curve.bigAffineToField(x1, y1)
+	fx2, fy2 := curve.bigAffineToField(x2, y2)
+	fx3, fy3, fz3 := new(fieldVal), new(fieldVal), new(fieldVal)
+	fOne := new(fieldVal).SetInt(1)
+	curve.addJacobian(fx1, fy1, fOne, fx2, fy2, fOne, fx3, fy3, fz3)
+
+	// Convert the Jacobian coordinate field values back to affine big
+	// integers.
+	return curve.fieldJacobianToBigAffine(fx3, fy3, fz3)
+}
+
+// doubleZ1EqualsOne performs point doubling on the passed Jacobian point
+// when the point is already known to have a z value of 1 and stores
+// the result in (x3, y3, z3).  That is to say (x3, y3, z3) = 2*(x1, y1, 1).  It
+// performs faster point doubling than the generic routine since less arithmetic
+// is needed due to the ability to avoid multiplication by the z value.
+func (curve *KoblitzCurve) doubleZ1EqualsOne(x1, y1, x3, y3, z3 *fieldVal) {
+	// This function uses the assumptions that z1 is 1, thus the point
+	// doubling formulas reduce to:
+	//
+	// X3 = (3*X1^2)^2 - 8*X1*Y1^2
+	// Y3 = (3*X1^2)*(4*X1*Y1^2 - X3) - 8*Y1^4
+	// Z3 = 2*Y1
+	//
+	// To compute the above efficiently, this implementation splits the
+	// equation into intermediate elements which are used to minimize the
+	// number of field multiplications in favor of field squarings which
+	// are roughly 35% faster than field multiplications with the current
+	// implementation at the time this was written.
+	//
+	// This uses a slightly modified version of the method shown at:
+	// http://hyperelliptic.org/EFD/g1p/auto-shortw-jacobian-0.html#doubling-mdbl-2007-bl
+	//
+	// In particular it performs the calculations using the following:
+	// A = X1^2, B = Y1^2, C = B^2, D = 2*((X1+B)^2-A-C)
+	// E = 3*A, F = E^2, X3 = F-2*D, Y3 = E*(D-X3)-8*C
+	// Z3 = 2*Y1
+	//
+	// This results in a cost of 1 field multiplication, 5 field squarings,
+	// 6 field additions, and 5 integer multiplications.
+	var a, b, c, d, e, f fieldVal
+	z3.Set(y1).MulInt(2)                     // Z3 = 2*Y1 (mag: 2)
+	a.SquareVal(x1)                          // A = X1^2 (mag: 1)
+	b.SquareVal(y1)                          // B = Y1^2 (mag: 1)
+	c.SquareVal(&b)                          // C = B^2 (mag: 1)
+	b.Add(x1).Square()                       // B = (X1+B)^2 (mag: 1)
+	d.Set(&a).Add(&c).Negate(2)              // D = -(A+C) (mag: 3)
+	d.Add(&b).MulInt(2)                      // D = 2*(B+D)(mag: 8)
+	e.Set(&a).MulInt(3)                      // E = 3*A (mag: 3)
+	f.SquareVal(&e)                          // F = E^2 (mag: 1)
+	x3.Set(&d).MulInt(2).Negate(16)          // X3 = -(2*D) (mag: 17)
+	x3.Add(&f)                               // X3 = F+X3 (mag: 18)
+	f.Set(x3).Negate(18).Add(&d).Normalize() // F = D-X3 (mag: 1)
+	y3.Set(&c).MulInt(8).Negate(8)           // Y3 = -(8*C) (mag: 9)
+	y3.Add(f.Mul(&e))                        // Y3 = E*F+Y3 (mag: 10)
+
+	// Normalize the field values back to a magnitude of 1.
+	x3.Normalize()
+	y3.Normalize()
+	z3.Normalize()
+}
+
+// doubleGeneric performs point doubling on the passed Jacobian point without
+// any assumptions about the z value and stores the result in (x3, y3, z3).
+// That is to say (x3, y3, z3) = 2*(x1, y1, z1).  It is the slowest of the point
+// doubling routines due to requiring the most arithmetic.
+func (curve *KoblitzCurve) doubleGeneric(x1, y1, z1, x3, y3, z3 *fieldVal) {
+	// Point doubling formula for Jacobian coordinates for the secp256k1
+	// curve:
+	// X3 = (3*X1^2)^2 - 8*X1*Y1^2
+	// Y3 = (3*X1^2)*(4*X1*Y1^2 - X3) - 8*Y1^4
+	// Z3 = 2*Y1*Z1
+	//
+	// To compute the above efficiently, this implementation splits the
+	// equation into intermediate elements which are used to minimize the
+	// number of field multiplications in favor of field squarings which
+	// are roughly 35% faster than field multiplications with the current
+	// implementation at the time this was written.
+	//
+	// This uses a slightly modified version of the method shown at:
+	// http://hyperelliptic.org/EFD/g1p/auto-shortw-jacobian-0.html#doubling-dbl-2009-l
+	//
+	// In particular it performs the calculations using the following:
+	// A = X1^2, B = Y1^2, C = B^2, D = 2*((X1+B)^2-A-C)
+	// E = 3*A, F = E^2, X3 = F-2*D, Y3 = E*(D-X3)-8*C
+	// Z3 = 2*Y1*Z1
+	//
+	// This results in a cost of 1 field multiplication, 5 field squarings,
+	// 6 field additions, and 5 integer multiplications.
+	var a, b, c, d, e, f fieldVal
+	z3.Mul2(y1, z1).MulInt(2)                // Z3 = 2*Y1*Z1 (mag: 2)
+	a.SquareVal(x1)                          // A = X1^2 (mag: 1)
+	b.SquareVal(y1)                          // B = Y1^2 (mag: 1)
+	c.SquareVal(&b)                          // C = B^2 (mag: 1)
+	b.Add(x1).Square()                       // B = (X1+B)^2 (mag: 1)
+	d.Set(&a).Add(&c).Negate(2)              // D = -(A+C) (mag: 3)
+	d.Add(&b).MulInt(2)                      // D = 2*(B+D)(mag: 8)
+	e.Set(&a).MulInt(3)                      // E = 3*A (mag: 3)
+	f.SquareVal(&e)                          // F = E^2 (mag: 1)
+	x3.Set(&d).MulInt(2).Negate(16)          // X3 = -(2*D) (mag: 17)
+	x3.Add(&f)                               // X3 = F+X3 (mag: 18)
+	f.Set(x3).Negate(18).Add(&d).Normalize() // F = D-X3 (mag: 1)
+	y3.Set(&c).MulInt(8).Negate(8)           // Y3 = -(8*C) (mag: 9)
+	y3.Add(f.Mul(&e))                        // Y3 = E*F+Y3 (mag: 10)
+
+	// Normalize the field values back to a magnitude of 1.
+	x3.Normalize()
+	y3.Normalize()
+	z3.Normalize()
+}
+
+// doubleJacobian doubles the passed Jacobian point (x1, y1, z1) and stores the
+// result in (x3, y3, z3).
+func (curve *KoblitzCurve) doubleJacobian(x1, y1, z1, x3, y3, z3 *fieldVal) {
+	// Doubling a point at infinity is still infinity.
+	if y1.IsZero() || z1.IsZero() {
+		x3.SetInt(0)
+		y3.SetInt(0)
+		z3.SetInt(0)
+		return
+	}
+
+	// Slightly faster point doubling can be achieved when the z value is 1
+	// by avoiding the multiplication on the z value.  This section calls
+	// a point doubling function which is accelerated by using that
+	// assumption when possible.
+	if z1.Normalize().Equals(fieldOne) {
+		curve.doubleZ1EqualsOne(x1, y1, x3, y3, z3)
+		return
+	}
+
+	// Fall back to generic point doubling which works with arbitrary z
+	// values.
+	curve.doubleGeneric(x1, y1, z1, x3, y3, z3)
+}
+
+// Double returns 2*(x1,y1). Part of the elliptic.Curve interface.
+func (curve *KoblitzCurve) Double(x1, y1 *big.Int) (*big.Int, *big.Int) {
+	if y1.Sign() == 0 {
+		return new(big.Int), new(big.Int)
+	}
+
+	// Convert the affine coordinates from big integers to field values
+	// and do the point doubling in Jacobian projective space.
+	fx1, fy1 := curve.bigAffineToField(x1, y1)
+	fx3, fy3, fz3 := new(fieldVal), new(fieldVal), new(fieldVal)
+	fOne := new(fieldVal).SetInt(1)
+	curve.doubleJacobian(fx1, fy1, fOne, fx3, fy3, fz3)
+
+	// Convert the Jacobian coordinate field values back to affine big
+	// integers.
+	return curve.fieldJacobianToBigAffine(fx3, fy3, fz3)
+}
+
+// splitK returns a balanced length-two representation of k and their signs.
+// This is algorithm 3.74 from [GECC].
+//
+// One thing of note about this algorithm is that no matter what c1 and c2 are,
+// the final equation of k = k1 + k2 * lambda (mod n) will hold.  This is
+// provable mathematically due to how a1/b1/a2/b2 are computed.
+//
+// c1 and c2 are chosen to minimize the max(k1,k2).
+func (curve *KoblitzCurve) splitK(k []byte) ([]byte, []byte, int, int) {
+	// All math here is done with big.Int, which is slow.
+	// At some point, it might be useful to write something similar to
+	// fieldVal but for N instead of P as the prime field if this ends up
+	// being a bottleneck.
+	bigIntK := new(big.Int)
+	c1, c2 := new(big.Int), new(big.Int)
+	tmp1, tmp2 := new(big.Int), new(big.Int)
+	k1, k2 := new(big.Int), new(big.Int)
+
+	bigIntK.SetBytes(k)
+	// c1 = round(b2 * k / n) from step 4.
+	// Rounding isn't really necessary and costs too much, hence skipped
+	c1.Mul(curve.b2, bigIntK)
+	c1.Div(c1, curve.N)
+	// c2 = round(b1 * k / n) from step 4 (sign reversed to optimize one step)
+	// Rounding isn't really necessary and costs too much, hence skipped
+	c2.Mul(curve.b1, bigIntK)
+	c2.Div(c2, curve.N)
+	// k1 = k - c1 * a1 - c2 * a2 from step 5 (note c2's sign is reversed)
+	tmp1.Mul(c1, curve.a1)
+	tmp2.Mul(c2, curve.a2)
+	k1.Sub(bigIntK, tmp1)
+	k1.Add(k1, tmp2)
+	// k2 = - c1 * b1 - c2 * b2 from step 5 (note c2's sign is reversed)
+	tmp1.Mul(c1, curve.b1)
+	tmp2.Mul(c2, curve.b2)
+	k2.Sub(tmp2, tmp1)
+
+	// Note Bytes() throws out the sign of k1 and k2. This matters
+	// since k1 and/or k2 can be negative. Hence, we pass that
+	// back separately.
+	return k1.Bytes(), k2.Bytes(), k1.Sign(), k2.Sign()
+}
+
+// moduloReduce reduces k from more than 32 bytes to 32 bytes and under.  This
+// is done by doing a simple modulo curve.N.  We can do this since G^N = 1 and
+// thus any other valid point on the elliptic curve has the same order.
+func (curve *KoblitzCurve) moduloReduce(k []byte) []byte {
+	// Since the order of G is curve.N, we can use a much smaller number
+	// by doing modulo curve.N
+	if len(k) > curve.byteSize {
+		// Reduce k by performing modulo curve.N.
+		tmpK := new(big.Int).SetBytes(k)
+		tmpK.Mod(tmpK, curve.N)
+		return tmpK.Bytes()
+	}
+
+	return k
+}
+
+// NAF takes a positive integer k and returns the Non-Adjacent Form (NAF) as two
+// byte slices.  The first is where 1s will be.  The second is where -1s will
+// be.  NAF is convenient in that on average, only 1/3rd of its values are
+// non-zero.  This is algorithm 3.30 from [GECC].
+//
+// Essentially, this makes it possible to minimize the number of operations
+// since the resulting ints returned will be at least 50% 0s.
+func NAF(k []byte) ([]byte, []byte) {
+	// The essence of this algorithm is that whenever we have consecutive 1s
+	// in the binary, we want to put a -1 in the lowest bit and get a bunch
+	// of 0s up to the highest bit of consecutive 1s.  This is due to this
+	// identity:
+	// 2^n + 2^(n-1) + 2^(n-2) + ... + 2^(n-k) = 2^(n+1) - 2^(n-k)
+	//
+	// The algorithm thus may need to go 1 more bit than the length of the
+	// bits we actually have, hence bits being 1 bit longer than was
+	// necessary.  Since we need to know whether adding will cause a carry,
+	// we go from right-to-left in this addition.
+	var carry, curIsOne, nextIsOne bool
+	// these default to zero
+	retPos := make([]byte, len(k)+1)
+	retNeg := make([]byte, len(k)+1)
+	for i := len(k) - 1; i >= 0; i-- {
+		curByte := k[i]
+		for j := uint(0); j < 8; j++ {
+			curIsOne = curByte&1 == 1
+			if j == 7 {
+				if i == 0 {
+					nextIsOne = false
+				} else {
+					nextIsOne = k[i-1]&1 == 1
+				}
+			} else {
+				nextIsOne = curByte&2 == 2
+			}
+			if carry {
+				if curIsOne {
+					// This bit is 1, so continue to carry
+					// and don't need to do anything.
+				} else {
+					// We've hit a 0 after some number of
+					// 1s.
+					if nextIsOne {
+						// Start carrying again since
+						// a new sequence of 1s is
+						// starting.
+						retNeg[i+1] += 1 << j
+					} else {
+						// Stop carrying since 1s have
+						// stopped.
+						carry = false
+						retPos[i+1] += 1 << j
+					}
+				}
+			} else if curIsOne {
+				if nextIsOne {
+					// If this is the start of at least 2
+					// consecutive 1s, set the current one
+					// to -1 and start carrying.
+					retNeg[i+1] += 1 << j
+					carry = true
+				} else {
+					// This is a singleton, not consecutive
+					// 1s.
+					retPos[i+1] += 1 << j
+				}
+			}
+			curByte >>= 1
+		}
+	}
+	if carry {
+		retPos[0] = 1
+	}
+
+	return retPos, retNeg
+}
+
+// ScalarMult returns k*(Bx, By) where k is a big endian integer.
+// Part of the elliptic.Curve interface.
+func (curve *KoblitzCurve) ScalarMult(Bx, By *big.Int, k []byte) (*big.Int, *big.Int) {
+	// Point Q = ∞ (point at infinity).
+	qx, qy, qz := new(fieldVal), new(fieldVal), new(fieldVal)
+
+	// Decompose K into k1 and k2 in order to halve the number of EC ops.
+	// See Algorithm 3.74 in [GECC].
+	k1, k2, signK1, signK2 := curve.splitK(curve.moduloReduce(k))
+
+	// The main equation here to remember is:
+	//   k * P = k1 * P + k2 * ϕ(P)
+	//
+	// P1 below is P in the equation, P2 below is ϕ(P) in the equation
+	p1x, p1y := curve.bigAffineToField(Bx, By)
+	p1yNeg := new(fieldVal).NegateVal(p1y, 1)
+	p1z := new(fieldVal).SetInt(1)
+
+	// NOTE: ϕ(x,y) = (βx,y).  The Jacobian z coordinate is 1, so this math
+	// goes through.
+	p2x := new(fieldVal).Mul2(p1x, curve.beta)
+	p2y := new(fieldVal).Set(p1y)
+	p2yNeg := new(fieldVal).NegateVal(p2y, 1)
+	p2z := new(fieldVal).SetInt(1)
+
+	// Flip the positive and negative values of the points as needed
+	// depending on the signs of k1 and k2.  As mentioned in the equation
+	// above, each of k1 and k2 are multiplied by the respective point.
+	// Since -k * P is the same thing as k * -P, and the group law for
+	// elliptic curves states that P(x, y) = -P(x, -y), it's faster and
+	// simplifies the code to just make the point negative.
+	if signK1 == -1 {
+		p1y, p1yNeg = p1yNeg, p1y
+	}
+	if signK2 == -1 {
+		p2y, p2yNeg = p2yNeg, p2y
+	}
+
+	// NAF versions of k1 and k2 should have a lot more zeros.
+	//
+	// The Pos version of the bytes contain the +1s and the Neg versions
+	// contain the -1s.
+	k1PosNAF, k1NegNAF := NAF(k1)
+	k2PosNAF, k2NegNAF := NAF(k2)
+	k1Len := len(k1PosNAF)
+	k2Len := len(k2PosNAF)
+
+	m := k1Len
+	if m < k2Len {
+		m = k2Len
+	}
+
+	// Add left-to-right using the NAF optimization.  See algorithm 3.77
+	// from [GECC].  This should be faster overall since there will be a lot
+	// more instances of 0, hence reducing the number of Jacobian additions
+	// at the cost of 1 possible extra doubling.
+	var k1BytePos, k1ByteNeg, k2BytePos, k2ByteNeg byte
+	for i := 0; i < m; i++ {
+		// Since we're going left-to-right, pad the front with 0s.
+		if i < m-k1Len {
+			k1BytePos = 0
+			k1ByteNeg = 0
+		} else {
+			k1BytePos = k1PosNAF[i-(m-k1Len)]
+			k1ByteNeg = k1NegNAF[i-(m-k1Len)]
+		}
+		if i < m-k2Len {
+			k2BytePos = 0
+			k2ByteNeg = 0
+		} else {
+			k2BytePos = k2PosNAF[i-(m-k2Len)]
+			k2ByteNeg = k2NegNAF[i-(m-k2Len)]
+		}
+
+		for j := 7; j >= 0; j-- {
+			// Q = 2 * Q
+			curve.doubleJacobian(qx, qy, qz, qx, qy, qz)
+
+			if k1BytePos&0x80 == 0x80 {
+				curve.addJacobian(qx, qy, qz, p1x, p1y, p1z,
+					qx, qy, qz)
+			} else if k1ByteNeg&0x80 == 0x80 {
+				curve.addJacobian(qx, qy, qz, p1x, p1yNeg, p1z,
+					qx, qy, qz)
+			}
+
+			if k2BytePos&0x80 == 0x80 {
+				curve.addJacobian(qx, qy, qz, p2x, p2y, p2z,
+					qx, qy, qz)
+			} else if k2ByteNeg&0x80 == 0x80 {
+				curve.addJacobian(qx, qy, qz, p2x, p2yNeg, p2z,
+					qx, qy, qz)
+			}
+			k1BytePos <<= 1
+			k1ByteNeg <<= 1
+			k2BytePos <<= 1
+			k2ByteNeg <<= 1
+		}
+	}
+
+	// Convert the Jacobian coordinate field values back to affine big.Ints.
+	return curve.fieldJacobianToBigAffine(qx, qy, qz)
+}
+
+// ScalarBaseMult returns k*G where G is the base point of the group and k is a
+// big endian integer.
+// Part of the elliptic.Curve interface.
+func (curve *KoblitzCurve) ScalarBaseMult(k []byte) (*big.Int, *big.Int) {
+	newK := curve.moduloReduce(k)
+	diff := len(curve.bytePoints) - len(newK)
+
+	// Point Q = ∞ (point at infinity).
+	qx, qy, qz := new(fieldVal), new(fieldVal), new(fieldVal)
+
+	// curve.bytePoints has all 256 byte points for each 8-bit window. The
+	// strategy is to add up the byte points. This is best understood by
+	// expressing k in base-256 which it already sort of is.
+	// Each "digit" in the 8-bit window can be looked up using bytePoints
+	// and added together.
+	for i, byteVal := range newK {
+		p := curve.bytePoints[diff+i][byteVal]
+		curve.addJacobian(qx, qy, qz, &p[0], &p[1], &p[2], qx, qy, qz)
+	}
+	return curve.fieldJacobianToBigAffine(qx, qy, qz)
+}
+
+// QPlus1Div4 returns the Q+1/4 constant for the curve for use in calculating
+// square roots via exponention.
+func (curve *KoblitzCurve) QPlus1Div4() *big.Int {
+	return curve.q
+}
+
+var initonce sync.Once
+var secp256k1 KoblitzCurve
+
+func initAll() {
+	initS256()
+}
+
+// fromHex converts the passed hex string into a big integer pointer and will
+// panic is there is an error.  This is only provided for the hard-coded
+// constants so errors in the source code can bet detected. It will only (and
+// must only) be called for initialization purposes.
+func fromHex(s string) *big.Int {
+	r, ok := new(big.Int).SetString(s, 16)
+	if !ok {
+		panic("invalid hex in source file: " + s)
+	}
+	return r
+}
+
+func initS256() {
+	// Curve parameters taken from [SECG] section 2.4.1.
+	secp256k1.CurveParams = new(elliptic.CurveParams)
+	secp256k1.P = fromHex("FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFEFFFFFC2F")
+	secp256k1.N = fromHex("FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFEBAAEDCE6AF48A03BBFD25E8CD0364141")
+	secp256k1.B = fromHex("0000000000000000000000000000000000000000000000000000000000000007")
+	secp256k1.Gx = fromHex("79BE667EF9DCBBAC55A06295CE870B07029BFCDB2DCE28D959F2815B16F81798")
+	secp256k1.Gy = fromHex("483ADA7726A3C4655DA4FBFC0E1108A8FD17B448A68554199C47D08FFB10D4B8")
+	secp256k1.BitSize = 256
+	secp256k1.H = 1
+	secp256k1.q = new(big.Int).Div(new(big.Int).Add(secp256k1.P,
+		big.NewInt(1)), big.NewInt(4))
+
+	// Provided for convenience since this gets computed repeatedly.
+	secp256k1.byteSize = secp256k1.BitSize / 8
+
+	// Deserialize and set the pre-computed table used to accelerate scalar
+	// base multiplication.  This is hard-coded data, so any errors are
+	// panics because it means something is wrong in the source code.
+	if err := loadS256BytePoints(); err != nil {
+		panic(err)
+	}
+
+	// Next 6 constants are from Hal Finney's bitcointalk.org post:
+	// https://bitcointalk.org/index.php?topic=3238.msg45565#msg45565
+	// May he rest in peace.
+	//
+	// They have also been independently derived from the code in the
+	// EndomorphismVectors function in gensecp256k1.go.
+	secp256k1.lambda = fromHex("5363AD4CC05C30E0A5261C028812645A122E22EA20816678DF02967C1B23BD72")
+	secp256k1.beta = new(fieldVal).SetHex("7AE96A2B657C07106E64479EAC3434E99CF0497512F58995C1396C28719501EE")
+	secp256k1.a1 = fromHex("3086D221A7D46BCDE86C90E49284EB15")
+	secp256k1.b1 = fromHex("-E4437ED6010E88286F547FA90ABFE4C3")
+	secp256k1.a2 = fromHex("114CA50F7A8E2F3F657C1108D9D44CFD8")
+	secp256k1.b2 = fromHex("3086D221A7D46BCDE86C90E49284EB15")
+
+	// Alternatively, we can use the parameters below, however, they seem
+	//  to be about 8% slower.
+	// secp256k1.lambda = fromHex("AC9C52B33FA3CF1F5AD9E3FD77ED9BA4A880B9FC8EC739C2E0CFC810B51283CE")
+	// secp256k1.beta = new(fieldVal).SetHex("851695D49A83F8EF919BB86153CBCB16630FB68AED0A766A3EC693D68E6AFA40")
+	// secp256k1.a1 = fromHex("E4437ED6010E88286F547FA90ABFE4C3")
+	// secp256k1.b1 = fromHex("-3086D221A7D46BCDE86C90E49284EB15")
+	// secp256k1.a2 = fromHex("3086D221A7D46BCDE86C90E49284EB15")
+	// secp256k1.b2 = fromHex("114CA50F7A8E2F3F657C1108D9D44CFD8")
+}
+
+// S256 returns a Curve which implements secp256k1.
+func S256() *KoblitzCurve {
+	initonce.Do(initAll)
+	return &secp256k1
+}

vendor/github.com/btcsuite/btcd/btcec/ciphering.go

@@ -0,0 +1,216 @@
+// Copyright (c) 2015-2016 The btcsuite developers
+// Use of this source code is governed by an ISC
+// license that can be found in the LICENSE file.
+
+package btcec
+
+import (
+	"bytes"
+	"crypto/aes"
+	"crypto/cipher"
+	"crypto/hmac"
+	"crypto/rand"
+	"crypto/sha256"
+	"crypto/sha512"
+	"errors"
+	"io"
+)
+
+var (
+	// ErrInvalidMAC occurs when Message Authentication Check (MAC) fails
+	// during decryption. This happens because of either invalid private key or
+	// corrupt ciphertext.
+	ErrInvalidMAC = errors.New("invalid mac hash")
+
+	// errInputTooShort occurs when the input ciphertext to the Decrypt
+	// function is less than 134 bytes long.
+	errInputTooShort = errors.New("ciphertext too short")
+
+	// errUnsupportedCurve occurs when the first two bytes of the encrypted
+	// text aren't 0x02CA (= 712 = secp256k1, from OpenSSL).
+	errUnsupportedCurve = errors.New("unsupported curve")
+
+	errInvalidXLength = errors.New("invalid X length, must be 32")
+	errInvalidYLength = errors.New("invalid Y length, must be 32")
+	errInvalidPadding = errors.New("invalid PKCS#7 padding")
+
+	// 0x02CA = 714
+	ciphCurveBytes = [2]byte{0x02, 0xCA}
+	// 0x20 = 32
+	ciphCoordLength = [2]byte{0x00, 0x20}
+)
+
+// GenerateSharedSecret generates a shared secret based on a private key and a
+// public key using Diffie-Hellman key exchange (ECDH) (RFC 4753).
+// RFC5903 Section 9 states we should only return x.
+func GenerateSharedSecret(privkey *PrivateKey, pubkey *PublicKey) []byte {
+	x, _ := pubkey.Curve.ScalarMult(pubkey.X, pubkey.Y, privkey.D.Bytes())
+	return x.Bytes()
+}
+
+// Encrypt encrypts data for the target public key using AES-256-CBC. It also
+// generates a private key (the pubkey of which is also in the output). The only
+// supported curve is secp256k1. The `structure' that it encodes everything into
+// is:
+//
+//	struct {
+//		// Initialization Vector used for AES-256-CBC
+//		IV [16]byte
+//		// Public Key: curve(2) + len_of_pubkeyX(2) + pubkeyX +
+//		// len_of_pubkeyY(2) + pubkeyY (curve = 714)
+//		PublicKey [70]byte
+//		// Cipher text
+//		Data []byte
+//		// HMAC-SHA-256 Message Authentication Code
+//		HMAC [32]byte
+//	}
+//
+// The primary aim is to ensure byte compatibility with Pyelliptic.  Also, refer
+// to section 5.8.1 of ANSI X9.63 for rationale on this format.
+func Encrypt(pubkey *PublicKey, in []byte) ([]byte, error) {
+	ephemeral, err := NewPrivateKey(S256())
+	if err != nil {
+		return nil, err
+	}
+	ecdhKey := GenerateSharedSecret(ephemeral, pubkey)
+	derivedKey := sha512.Sum512(ecdhKey)
+	keyE := derivedKey[:32]
+	keyM := derivedKey[32:]
+
+	paddedIn := addPKCSPadding(in)
+	// IV + Curve params/X/Y + padded plaintext/ciphertext + HMAC-256
+	out := make([]byte, aes.BlockSize+70+len(paddedIn)+sha256.Size)
+	iv := out[:aes.BlockSize]
+	if _, err = io.ReadFull(rand.Reader, iv); err != nil {
+		return nil, err
+	}
+	// start writing public key
+	pb := ephemeral.PubKey().SerializeUncompressed()
+	offset := aes.BlockSize
+
+	// curve and X length
+	copy(out[offset:offset+4], append(ciphCurveBytes[:], ciphCoordLength[:]...))
+	offset += 4
+	// X
+	copy(out[offset:offset+32], pb[1:33])
+	offset += 32
+	// Y length
+	copy(out[offset:offset+2], ciphCoordLength[:])
+	offset += 2
+	// Y
+	copy(out[offset:offset+32], pb[33:])
+	offset += 32
+
+	// start encryption
+	block, err := aes.NewCipher(keyE)
+	if err != nil {
+		return nil, err
+	}
+	mode := cipher.NewCBCEncrypter(block, iv)
+	mode.CryptBlocks(out[offset:len(out)-sha256.Size], paddedIn)
+
+	// start HMAC-SHA-256
+	hm := hmac.New(sha256.New, keyM)
+	hm.Write(out[:len(out)-sha256.Size])          // everything is hashed
+	copy(out[len(out)-sha256.Size:], hm.Sum(nil)) // write checksum
+
+	return out, nil
+}
+
+// Decrypt decrypts data that was encrypted using the Encrypt function.
+func Decrypt(priv *PrivateKey, in []byte) ([]byte, error) {
+	// IV + Curve params/X/Y + 1 block + HMAC-256
+	if len(in) < aes.BlockSize+70+aes.BlockSize+sha256.Size {
+		return nil, errInputTooShort
+	}
+
+	// read iv
+	iv := in[:aes.BlockSize]
+	offset := aes.BlockSize
+
+	// start reading pubkey
+	if !bytes.Equal(in[offset:offset+2], ciphCurveBytes[:]) {
+		return nil, errUnsupportedCurve
+	}
+	offset += 2
+
+	if !bytes.Equal(in[offset:offset+2], ciphCoordLength[:]) {
+		return nil, errInvalidXLength
+	}
+	offset += 2
+
+	xBytes := in[offset : offset+32]
+	offset += 32
+
+	if !bytes.Equal(in[offset:offset+2], ciphCoordLength[:]) {
+		return nil, errInvalidYLength
+	}
+	offset += 2
+
+	yBytes := in[offset : offset+32]
+	offset += 32
+
+	pb := make([]byte, 65)
+	pb[0] = byte(0x04) // uncompressed
+	copy(pb[1:33], xBytes)
+	copy(pb[33:], yBytes)
+	// check if (X, Y) lies on the curve and create a Pubkey if it does
+	pubkey, err := ParsePubKey(pb, S256())
+	if err != nil {
+		return nil, err
+	}
+
+	// check for cipher text length
+	if (len(in)-aes.BlockSize-offset-sha256.Size)%aes.BlockSize != 0 {
+		return nil, errInvalidPadding // not padded to 16 bytes
+	}
+
+	// read hmac
+	messageMAC := in[len(in)-sha256.Size:]
+
+	// generate shared secret
+	ecdhKey := GenerateSharedSecret(priv, pubkey)
+	derivedKey := sha512.Sum512(ecdhKey)
+	keyE := derivedKey[:32]
+	keyM := derivedKey[32:]
+
+	// verify mac
+	hm := hmac.New(sha256.New, keyM)
+	hm.Write(in[:len(in)-sha256.Size]) // everything is hashed
+	expectedMAC := hm.Sum(nil)
+	if !hmac.Equal(messageMAC, expectedMAC) {
+		return nil, ErrInvalidMAC
+	}
+
+	// start decryption
+	block, err := aes.NewCipher(keyE)
+	if err != nil {
+		return nil, err
+	}
+	mode := cipher.NewCBCDecrypter(block, iv)
+	// same length as ciphertext
+	plaintext := make([]byte, len(in)-offset-sha256.Size)
+	mode.CryptBlocks(plaintext, in[offset:len(in)-sha256.Size])
+
+	return removePKCSPadding(plaintext)
+}
+
+// Implement PKCS#7 padding with block size of 16 (AES block size).
+
+// addPKCSPadding adds padding to a block of data
+func addPKCSPadding(src []byte) []byte {
+	padding := aes.BlockSize - len(src)%aes.BlockSize
+	padtext := bytes.Repeat([]byte{byte(padding)}, padding)
+	return append(src, padtext...)
+}
+
+// removePKCSPadding removes padding from data that was added with addPKCSPadding
+func removePKCSPadding(src []byte) ([]byte, error) {
+	length := len(src)
+	padLength := int(src[length-1])
+	if padLength > aes.BlockSize || length < aes.BlockSize {
+		return nil, errInvalidPadding
+	}
+
+	return src[:length-padLength], nil
+}

vendor/github.com/btcsuite/btcd/btcec/doc.go

@@ -0,0 +1,21 @@
+// Copyright (c) 2013-2014 The btcsuite developers
+// Use of this source code is governed by an ISC
+// license that can be found in the LICENSE file.
+
+/*
+Package btcec implements support for the elliptic curves needed for bitcoin.
+
+Bitcoin uses elliptic curve cryptography using koblitz curves
+(specifically secp256k1) for cryptographic functions.  See
+http://www.secg.org/collateral/sec2_final.pdf for details on the
+standard.
+
+This package provides the data structures and functions implementing the
+crypto/elliptic Curve interface in order to permit using these curves
+with the standard crypto/ecdsa package provided with go. Helper
+functionality is provided to parse signatures and public keys from
+standard formats.  It was designed for use with btcd, but should be
+general enough for other uses of elliptic curve crypto.  It was originally based
+on some initial work by ThePiachu, but has significantly diverged since then.
+*/
+package btcec

vendor/github.com/btcsuite/btcd/btcec/genprecomps.go

@@ -0,0 +1,63 @@
+// Copyright 2015 The btcsuite developers
+// Use of this source code is governed by an ISC
+// license that can be found in the LICENSE file.
+
+// This file is ignored during the regular build due to the following build tag.
+// It is called by go generate and used to automatically generate pre-computed
+// tables used to accelerate operations.
+// +build ignore
+
+package main
+
+import (
+	"bytes"
+	"compress/zlib"
+	"encoding/base64"
+	"fmt"
+	"log"
+	"os"
+
+	"github.com/btcsuite/btcd/btcec"
+)
+
+func main() {
+	fi, err := os.Create("secp256k1.go")
+	if err != nil {
+		log.Fatal(err)
+	}
+	defer fi.Close()
+
+	// Compress the serialized byte points.
+	serialized := btcec.S256().SerializedBytePoints()
+	var compressed bytes.Buffer
+	w := zlib.NewWriter(&compressed)
+	if _, err := w.Write(serialized); err != nil {
+		fmt.Println(err)
+		os.Exit(1)
+	}
+	w.Close()
+
+	// Encode the compressed byte points with base64.
+	encoded := make([]byte, base64.StdEncoding.EncodedLen(compressed.Len()))
+	base64.StdEncoding.Encode(encoded, compressed.Bytes())
+
+	fmt.Fprintln(fi, "// Copyright (c) 2015 The btcsuite developers")
+	fmt.Fprintln(fi, "// Use of this source code is governed by an ISC")
+	fmt.Fprintln(fi, "// license that can be found in the LICENSE file.")
+	fmt.Fprintln(fi)
+	fmt.Fprintln(fi, "package btcec")
+	fmt.Fprintln(fi)
+	fmt.Fprintln(fi, "// Auto-generated file (see genprecomps.go)")
+	fmt.Fprintln(fi, "// DO NOT EDIT")
+	fmt.Fprintln(fi)
+	fmt.Fprintf(fi, "var secp256k1BytePoints = %q\n", string(encoded))
+
+	a1, b1, a2, b2 := btcec.S256().EndomorphismVectors()
+	fmt.Println("The following values are the computed linearly " +
+		"independent vectors needed to make use of the secp256k1 " +
+		"endomorphism:")
+	fmt.Printf("a1: %x\n", a1)
+	fmt.Printf("b1: %x\n", b1)
+	fmt.Printf("a2: %x\n", a2)
+	fmt.Printf("b2: %x\n", b2)
+}

vendor/github.com/btcsuite/btcd/btcec/gensecp256k1.go

@@ -0,0 +1,203 @@
+// Copyright (c) 2014-2015 The btcsuite developers
+// Use of this source code is governed by an ISC
+// license that can be found in the LICENSE file.
+
+// This file is ignored during the regular build due to the following build tag.
+// This build tag is set during go generate.
+// +build gensecp256k1
+
+package btcec
+
+// References:
+//   [GECC]: Guide to Elliptic Curve Cryptography (Hankerson, Menezes, Vanstone)
+
+import (
+	"encoding/binary"
+	"math/big"
+)
+
+// secp256k1BytePoints are dummy points used so the code which generates the
+// real values can compile.
+var secp256k1BytePoints = ""
+
+// getDoublingPoints returns all the possible G^(2^i) for i in
+// 0..n-1 where n is the curve's bit size (256 in the case of secp256k1)
+// the coordinates are recorded as Jacobian coordinates.
+func (curve *KoblitzCurve) getDoublingPoints() [][3]fieldVal {
+	doublingPoints := make([][3]fieldVal, curve.BitSize)
+
+	// initialize px, py, pz to the Jacobian coordinates for the base point
+	px, py := curve.bigAffineToField(curve.Gx, curve.Gy)
+	pz := new(fieldVal).SetInt(1)
+	for i := 0; i < curve.BitSize; i++ {
+		doublingPoints[i] = [3]fieldVal{*px, *py, *pz}
+		// P = 2*P
+		curve.doubleJacobian(px, py, pz, px, py, pz)
+	}
+	return doublingPoints
+}
+
+// SerializedBytePoints returns a serialized byte slice which contains all of
+// the possible points per 8-bit window.  This is used to when generating
+// secp256k1.go.
+func (curve *KoblitzCurve) SerializedBytePoints() []byte {
+	doublingPoints := curve.getDoublingPoints()
+
+	// Segregate the bits into byte-sized windows
+	serialized := make([]byte, curve.byteSize*256*3*10*4)
+	offset := 0
+	for byteNum := 0; byteNum < curve.byteSize; byteNum++ {
+		// Grab the 8 bits that make up this byte from doublingPoints.
+		startingBit := 8 * (curve.byteSize - byteNum - 1)
+		computingPoints := doublingPoints[startingBit : startingBit+8]
+
+		// Compute all points in this window and serialize them.
+		for i := 0; i < 256; i++ {
+			px, py, pz := new(fieldVal), new(fieldVal), new(fieldVal)
+			for j := 0; j < 8; j++ {
+				if i>>uint(j)&1 == 1 {
+					curve.addJacobian(px, py, pz, &computingPoints[j][0],
+						&computingPoints[j][1], &computingPoints[j][2], px, py, pz)
+				}
+			}
+			for i := 0; i < 10; i++ {
+				binary.LittleEndian.PutUint32(serialized[offset:], px.n[i])
+				offset += 4
+			}
+			for i := 0; i < 10; i++ {
+				binary.LittleEndian.PutUint32(serialized[offset:], py.n[i])
+				offset += 4
+			}
+			for i := 0; i < 10; i++ {
+				binary.LittleEndian.PutUint32(serialized[offset:], pz.n[i])
+				offset += 4
+			}
+		}
+	}
+
+	return serialized
+}
+
+// sqrt returns the square root of the provided big integer using Newton's
+// method.  It's only compiled and used during generation of pre-computed
+// values, so speed is not a huge concern.
+func sqrt(n *big.Int) *big.Int {
+	// Initial guess = 2^(log_2(n)/2)
+	guess := big.NewInt(2)
+	guess.Exp(guess, big.NewInt(int64(n.BitLen()/2)), nil)
+
+	// Now refine using Newton's method.
+	big2 := big.NewInt(2)
+	prevGuess := big.NewInt(0)
+	for {
+		prevGuess.Set(guess)
+		guess.Add(guess, new(big.Int).Div(n, guess))
+		guess.Div(guess, big2)
+		if guess.Cmp(prevGuess) == 0 {
+			break
+		}
+	}
+	return guess
+}
+
+// EndomorphismVectors runs the first 3 steps of algorithm 3.74 from [GECC] to
+// generate the linearly independent vectors needed to generate a balanced
+// length-two representation of a multiplier such that k = k1 + k2λ (mod N) and
+// returns them.  Since the values will always be the same given the fact that N
+// and λ are fixed, the final results can be accelerated by storing the
+// precomputed values with the curve.
+func (curve *KoblitzCurve) EndomorphismVectors() (a1, b1, a2, b2 *big.Int) {
+	bigMinus1 := big.NewInt(-1)
+
+	// This section uses an extended Euclidean algorithm to generate a
+	// sequence of equations:
+	//  s[i] * N + t[i] * λ = r[i]
+
+	nSqrt := sqrt(curve.N)
+	u, v := new(big.Int).Set(curve.N), new(big.Int).Set(curve.lambda)
+	x1, y1 := big.NewInt(1), big.NewInt(0)
+	x2, y2 := big.NewInt(0), big.NewInt(1)
+	q, r := new(big.Int), new(big.Int)
+	qu, qx1, qy1 := new(big.Int), new(big.Int), new(big.Int)
+	s, t := new(big.Int), new(big.Int)
+	ri, ti := new(big.Int), new(big.Int)
+	a1, b1, a2, b2 = new(big.Int), new(big.Int), new(big.Int), new(big.Int)
+	found, oneMore := false, false
+	for u.Sign() != 0 {
+		// q = v/u
+		q.Div(v, u)
+
+		// r = v - q*u
+		qu.Mul(q, u)
+		r.Sub(v, qu)
+
+		// s = x2 - q*x1
+		qx1.Mul(q, x1)
+		s.Sub(x2, qx1)
+
+		// t = y2 - q*y1
+		qy1.Mul(q, y1)
+		t.Sub(y2, qy1)
+
+		// v = u, u = r, x2 = x1, x1 = s, y2 = y1, y1 = t
+		v.Set(u)
+		u.Set(r)
+		x2.Set(x1)
+		x1.Set(s)
+		y2.Set(y1)
+		y1.Set(t)
+
+		// As soon as the remainder is less than the sqrt of n, the
+		// values of a1 and b1 are known.
+		if !found && r.Cmp(nSqrt) < 0 {
+			// When this condition executes ri and ti represent the
+			// r[i] and t[i] values such that i is the greatest
+			// index for which r >= sqrt(n).  Meanwhile, the current
+			// r and t values are r[i+1] and t[i+1], respectively.
+
+			// a1 = r[i+1], b1 = -t[i+1]
+			a1.Set(r)
+			b1.Mul(t, bigMinus1)
+			found = true
+			oneMore = true
+
+			// Skip to the next iteration so ri and ti are not
+			// modified.
+			continue
+
+		} else if oneMore {
+			// When this condition executes ri and ti still
+			// represent the r[i] and t[i] values while the current
+			// r and t are r[i+2] and t[i+2], respectively.
+
+			// sum1 = r[i]^2 + t[i]^2
+			rSquared := new(big.Int).Mul(ri, ri)
+			tSquared := new(big.Int).Mul(ti, ti)
+			sum1 := new(big.Int).Add(rSquared, tSquared)
+
+			// sum2 = r[i+2]^2 + t[i+2]^2
+			r2Squared := new(big.Int).Mul(r, r)
+			t2Squared := new(big.Int).Mul(t, t)
+			sum2 := new(big.Int).Add(r2Squared, t2Squared)
+
+			// if (r[i]^2 + t[i]^2) <= (r[i+2]^2 + t[i+2]^2)
+			if sum1.Cmp(sum2) <= 0 {
+				// a2 = r[i], b2 = -t[i]
+				a2.Set(ri)
+				b2.Mul(ti, bigMinus1)
+			} else {
+				// a2 = r[i+2], b2 = -t[i+2]
+				a2.Set(r)
+				b2.Mul(t, bigMinus1)
+			}
+
+			// All done.
+			break
+		}
+
+		ri.Set(r)
+		ti.Set(t)
+	}
+
+	return a1, b1, a2, b2
+}

vendor/github.com/btcsuite/btcd/btcec/precompute.go

@@ -0,0 +1,67 @@
+// Copyright 2015 The btcsuite developers
+// Use of this source code is governed by an ISC
+// license that can be found in the LICENSE file.
+
+package btcec
+
+import (
+	"compress/zlib"
+	"encoding/base64"
+	"encoding/binary"
+	"io/ioutil"
+	"strings"
+)
+
+//go:generate go run -tags gensecp256k1 genprecomps.go
+
+// loadS256BytePoints decompresses and deserializes the pre-computed byte points
+// used to accelerate scalar base multiplication for the secp256k1 curve.  This
+// approach is used since it allows the compile to use significantly less ram
+// and be performed much faster than it is with hard-coding the final in-memory
+// data structure.  At the same time, it is quite fast to generate the in-memory
+// data structure at init time with this approach versus computing the table.
+func loadS256BytePoints() error {
+	// There will be no byte points to load when generating them.
+	bp := secp256k1BytePoints
+	if len(bp) == 0 {
+		return nil
+	}
+
+	// Decompress the pre-computed table used to accelerate scalar base
+	// multiplication.
+	decoder := base64.NewDecoder(base64.StdEncoding, strings.NewReader(bp))
+	r, err := zlib.NewReader(decoder)
+	if err != nil {
+		return err
+	}
+	serialized, err := ioutil.ReadAll(r)
+	if err != nil {
+		return err
+	}
+
+	// Deserialize the precomputed byte points and set the curve to them.
+	offset := 0
+	var bytePoints [32][256][3]fieldVal
+	for byteNum := 0; byteNum < 32; byteNum++ {
+		// All points in this window.
+		for i := 0; i < 256; i++ {
+			px := &bytePoints[byteNum][i][0]
+			py := &bytePoints[byteNum][i][1]
+			pz := &bytePoints[byteNum][i][2]
+			for i := 0; i < 10; i++ {
+				px.n[i] = binary.LittleEndian.Uint32(serialized[offset:])
+				offset += 4
+			}
+			for i := 0; i < 10; i++ {
+				py.n[i] = binary.LittleEndian.Uint32(serialized[offset:])
+				offset += 4
+			}
+			for i := 0; i < 10; i++ {
+				pz.n[i] = binary.LittleEndian.Uint32(serialized[offset:])
+				offset += 4
+			}
+		}
+	}
+	secp256k1.bytePoints = &bytePoints
+	return nil
+}

vendor/github.com/btcsuite/btcd/btcec/privkey.go

@@ -0,0 +1,73 @@
+// Copyright (c) 2013-2016 The btcsuite developers
+// Use of this source code is governed by an ISC
+// license that can be found in the LICENSE file.
+
+package btcec
+
+import (
+	"crypto/ecdsa"
+	"crypto/elliptic"
+	"crypto/rand"
+	"math/big"
+)
+
+// PrivateKey wraps an ecdsa.PrivateKey as a convenience mainly for signing
+// things with the the private key without having to directly import the ecdsa
+// package.
+type PrivateKey ecdsa.PrivateKey
+
+// PrivKeyFromBytes returns a private and public key for `curve' based on the
+// private key passed as an argument as a byte slice.
+func PrivKeyFromBytes(curve elliptic.Curve, pk []byte) (*PrivateKey,
+	*PublicKey) {
+	x, y := curve.ScalarBaseMult(pk)
+
+	priv := &ecdsa.PrivateKey{
+		PublicKey: ecdsa.PublicKey{
+			Curve: curve,
+			X:     x,
+			Y:     y,
+		},
+		D: new(big.Int).SetBytes(pk),
+	}
+
+	return (*PrivateKey)(priv), (*PublicKey)(&priv.PublicKey)
+}
+
+// NewPrivateKey is a wrapper for ecdsa.GenerateKey that returns a PrivateKey
+// instead of the normal ecdsa.PrivateKey.
+func NewPrivateKey(curve elliptic.Curve) (*PrivateKey, error) {
+	key, err := ecdsa.GenerateKey(curve, rand.Reader)
+	if err != nil {
+		return nil, err
+	}
+	return (*PrivateKey)(key), nil
+}
+
+// PubKey returns the PublicKey corresponding to this private key.
+func (p *PrivateKey) PubKey() *PublicKey {
+	return (*PublicKey)(&p.PublicKey)
+}
+
+// ToECDSA returns the private key as a *ecdsa.PrivateKey.
+func (p *PrivateKey) ToECDSA() *ecdsa.PrivateKey {
+	return (*ecdsa.PrivateKey)(p)
+}
+
+// Sign generates an ECDSA signature for the provided hash (which should be the result
+// of hashing a larger message) using the private key. Produced signature
+// is deterministic (same message and same key yield the same signature) and canonical
+// in accordance with RFC6979 and BIP0062.
+func (p *PrivateKey) Sign(hash []byte) (*Signature, error) {
+	return signRFC6979(p, hash)
+}
+
+// PrivKeyBytesLen defines the length in bytes of a serialized private key.
+const PrivKeyBytesLen = 32
+
+// Serialize returns the private key number d as a big-endian binary-encoded
+// number, padded to a length of 32 bytes.
+func (p *PrivateKey) Serialize() []byte {
+	b := make([]byte, 0, PrivKeyBytesLen)
+	return paddedAppend(PrivKeyBytesLen, b, p.ToECDSA().D.Bytes())
+}

vendor/github.com/btcsuite/btcd/btcec/pubkey.go

@@ -0,0 +1,172 @@
+// Copyright (c) 2013-2014 The btcsuite developers
+// Use of this source code is governed by an ISC
+// license that can be found in the LICENSE file.
+
+package btcec
+
+import (
+	"crypto/ecdsa"
+	"errors"
+	"fmt"
+	"math/big"
+)
+
+// These constants define the lengths of serialized public keys.
+const (
+	PubKeyBytesLenCompressed   = 33
+	PubKeyBytesLenUncompressed = 65
+	PubKeyBytesLenHybrid       = 65
+)
+
+func isOdd(a *big.Int) bool {
+	return a.Bit(0) == 1
+}
+
+// decompressPoint decompresses a point on the given curve given the X point and
+// the solution to use.
+func decompressPoint(curve *KoblitzCurve, x *big.Int, ybit bool) (*big.Int, error) {
+	// TODO: This will probably only work for secp256k1 due to
+	// optimizations.
+
+	// Y = +-sqrt(x^3 + B)
+	x3 := new(big.Int).Mul(x, x)
+	x3.Mul(x3, x)
+	x3.Add(x3, curve.Params().B)
+
+	// now calculate sqrt mod p of x2 + B
+	// This code used to do a full sqrt based on tonelli/shanks,
+	// but this was replaced by the algorithms referenced in
+	// https://bitcointalk.org/index.php?topic=162805.msg1712294#msg1712294
+	y := new(big.Int).Exp(x3, curve.QPlus1Div4(), curve.Params().P)
+
+	if ybit != isOdd(y) {
+		y.Sub(curve.Params().P, y)
+	}
+	if ybit != isOdd(y) {
+		return nil, fmt.Errorf("ybit doesn't match oddness")
+	}
+	return y, nil
+}
+
+const (
+	pubkeyCompressed   byte = 0x2 // y_bit + x coord
+	pubkeyUncompressed byte = 0x4 // x coord + y coord
+	pubkeyHybrid       byte = 0x6 // y_bit + x coord + y coord
+)
+
+// ParsePubKey parses a public key for a koblitz curve from a bytestring into a
+// ecdsa.Publickey, verifying that it is valid. It supports compressed,
+// uncompressed and hybrid signature formats.
+func ParsePubKey(pubKeyStr []byte, curve *KoblitzCurve) (key *PublicKey, err error) {
+	pubkey := PublicKey{}
+	pubkey.Curve = curve
+
+	if len(pubKeyStr) == 0 {
+		return nil, errors.New("pubkey string is empty")
+	}
+
+	format := pubKeyStr[0]
+	ybit := (format & 0x1) == 0x1
+	format &= ^byte(0x1)
+
+	switch len(pubKeyStr) {
+	case PubKeyBytesLenUncompressed:
+		if format != pubkeyUncompressed && format != pubkeyHybrid {
+			return nil, fmt.Errorf("invalid magic in pubkey str: "+
+				"%d", pubKeyStr[0])
+		}
+
+		pubkey.X = new(big.Int).SetBytes(pubKeyStr[1:33])
+		pubkey.Y = new(big.Int).SetBytes(pubKeyStr[33:])
+		// hybrid keys have extra information, make use of it.
+		if format == pubkeyHybrid && ybit != isOdd(pubkey.Y) {
+			return nil, fmt.Errorf("ybit doesn't match oddness")
+		}
+	case PubKeyBytesLenCompressed:
+		// format is 0x2 | solution, <X coordinate>
+		// solution determines which solution of the curve we use.
+		/// y^2 = x^3 + Curve.B
+		if format != pubkeyCompressed {
+			return nil, fmt.Errorf("invalid magic in compressed "+
+				"pubkey string: %d", pubKeyStr[0])
+		}
+		pubkey.X = new(big.Int).SetBytes(pubKeyStr[1:33])
+		pubkey.Y, err = decompressPoint(curve, pubkey.X, ybit)
+		if err != nil {
+			return nil, err
+		}
+	default: // wrong!
+		return nil, fmt.Errorf("invalid pub key length %d",
+			len(pubKeyStr))
+	}
+
+	if pubkey.X.Cmp(pubkey.Curve.Params().P) >= 0 {
+		return nil, fmt.Errorf("pubkey X parameter is >= to P")
+	}
+	if pubkey.Y.Cmp(pubkey.Curve.Params().P) >= 0 {
+		return nil, fmt.Errorf("pubkey Y parameter is >= to P")
+	}
+	if !pubkey.Curve.IsOnCurve(pubkey.X, pubkey.Y) {
+		return nil, fmt.Errorf("pubkey isn't on secp256k1 curve")
+	}
+	return &pubkey, nil
+}
+
+// PublicKey is an ecdsa.PublicKey with additional functions to
+// serialize in uncompressed, compressed, and hybrid formats.
+type PublicKey ecdsa.PublicKey
+
+// ToECDSA returns the public key as a *ecdsa.PublicKey.
+func (p *PublicKey) ToECDSA() *ecdsa.PublicKey {
+	return (*ecdsa.PublicKey)(p)
+}
+
+// SerializeUncompressed serializes a public key in a 65-byte uncompressed
+// format.
+func (p *PublicKey) SerializeUncompressed() []byte {
+	b := make([]byte, 0, PubKeyBytesLenUncompressed)
+	b = append(b, pubkeyUncompressed)
+	b = paddedAppend(32, b, p.X.Bytes())
+	return paddedAppend(32, b, p.Y.Bytes())
+}
+
+// SerializeCompressed serializes a public key in a 33-byte compressed format.
+func (p *PublicKey) SerializeCompressed() []byte {
+	b := make([]byte, 0, PubKeyBytesLenCompressed)
+	format := pubkeyCompressed
+	if isOdd(p.Y) {
+		format |= 0x1
+	}
+	b = append(b, format)
+	return paddedAppend(32, b, p.X.Bytes())
+}
+
+// SerializeHybrid serializes a public key in a 65-byte hybrid format.
+func (p *PublicKey) SerializeHybrid() []byte {
+	b := make([]byte, 0, PubKeyBytesLenHybrid)
+	format := pubkeyHybrid
+	if isOdd(p.Y) {
+		format |= 0x1
+	}
+	b = append(b, format)
+	b = paddedAppend(32, b, p.X.Bytes())
+	return paddedAppend(32, b, p.Y.Bytes())
+}
+
+// IsEqual compares this PublicKey instance to the one passed, returning true if
+// both PublicKeys are equivalent. A PublicKey is equivalent to another, if they
+// both have the same X and Y coordinate.
+func (p *PublicKey) IsEqual(otherPubKey *PublicKey) bool {
+	return p.X.Cmp(otherPubKey.X) == 0 &&
+		p.Y.Cmp(otherPubKey.Y) == 0
+}
+
+// paddedAppend appends the src byte slice to dst, returning the new slice.
+// If the length of the source is smaller than the passed size, leading zero
+// bytes are appended to the dst slice before appending src.
+func paddedAppend(size uint, dst, src []byte) []byte {
+	for i := 0; i < int(size)-len(src); i++ {
+		dst = append(dst, 0)
+	}
+	return append(dst, src...)
+}

vendor/github.com/btcsuite/btcd/btcec/signature.go

@@ -0,0 +1,539 @@
+// Copyright (c) 2013-2017 The btcsuite developers
+// Use of this source code is governed by an ISC
+// license that can be found in the LICENSE file.
+
+package btcec
+
+import (
+	"bytes"
+	"crypto/ecdsa"
+	"crypto/elliptic"
+	"crypto/hmac"
+	"crypto/sha256"
+	"errors"
+	"fmt"
+	"hash"
+	"math/big"
+)
+
+// Errors returned by canonicalPadding.
+var (
+	errNegativeValue          = errors.New("value may be interpreted as negative")
+	errExcessivelyPaddedValue = errors.New("value is excessively padded")
+)
+
+// Signature is a type representing an ecdsa signature.
+type Signature struct {
+	R *big.Int
+	S *big.Int
+}
+
+var (
+	// Curve order and halforder, used to tame ECDSA malleability (see BIP-0062)
+	order     = new(big.Int).Set(S256().N)
+	halforder = new(big.Int).Rsh(order, 1)
+
+	// Used in RFC6979 implementation when testing the nonce for correctness
+	one = big.NewInt(1)
+
+	// oneInitializer is used to fill a byte slice with byte 0x01.  It is provided
+	// here to avoid the need to create it multiple times.
+	oneInitializer = []byte{0x01}
+)
+
+// Serialize returns the ECDSA signature in the more strict DER format.  Note
+// that the serialized bytes returned do not include the appended hash type
+// used in Bitcoin signature scripts.
+//
+// encoding/asn1 is broken so we hand roll this output:
+//
+// 0x30 <length> 0x02 <length r> r 0x02 <length s> s
+func (sig *Signature) Serialize() []byte {
+	// low 'S' malleability breaker
+	sigS := sig.S
+	if sigS.Cmp(halforder) == 1 {
+		sigS = new(big.Int).Sub(order, sigS)
+	}
+	// Ensure the encoded bytes for the r and s values are canonical and
+	// thus suitable for DER encoding.
+	rb := canonicalizeInt(sig.R)
+	sb := canonicalizeInt(sigS)
+
+	// total length of returned signature is 1 byte for each magic and
+	// length (6 total), plus lengths of r and s
+	length := 6 + len(rb) + len(sb)
+	b := make([]byte, length, length)
+
+	b[0] = 0x30
+	b[1] = byte(length - 2)
+	b[2] = 0x02
+	b[3] = byte(len(rb))
+	offset := copy(b[4:], rb) + 4
+	b[offset] = 0x02
+	b[offset+1] = byte(len(sb))
+	copy(b[offset+2:], sb)
+	return b
+}
+
+// Verify calls ecdsa.Verify to verify the signature of hash using the public
+// key.  It returns true if the signature is valid, false otherwise.
+func (sig *Signature) Verify(hash []byte, pubKey *PublicKey) bool {
+	return ecdsa.Verify(pubKey.ToECDSA(), hash, sig.R, sig.S)
+}
+
+// IsEqual compares this Signature instance to the one passed, returning true
+// if both Signatures are equivalent. A signature is equivalent to another, if
+// they both have the same scalar value for R and S.
+func (sig *Signature) IsEqual(otherSig *Signature) bool {
+	return sig.R.Cmp(otherSig.R) == 0 &&
+		sig.S.Cmp(otherSig.S) == 0
+}
+
+func parseSig(sigStr []byte, curve elliptic.Curve, der bool) (*Signature, error) {
+	// Originally this code used encoding/asn1 in order to parse the
+	// signature, but a number of problems were found with this approach.
+	// Despite the fact that signatures are stored as DER, the difference
+	// between go's idea of a bignum (and that they have sign) doesn't agree
+	// with the openssl one (where they do not). The above is true as of
+	// Go 1.1. In the end it was simpler to rewrite the code to explicitly
+	// understand the format which is this:
+	// 0x30 <length of whole message> <0x02> <length of R> <R> 0x2
+	// <length of S> <S>.
+
+	signature := &Signature{}
+
+	// minimal message is when both numbers are 1 bytes. adding up to:
+	// 0x30 + len + 0x02 + 0x01 + <byte> + 0x2 + 0x01 + <byte>
+	if len(sigStr) < 8 {
+		return nil, errors.New("malformed signature: too short")
+	}
+	// 0x30
+	index := 0
+	if sigStr[index] != 0x30 {
+		return nil, errors.New("malformed signature: no header magic")
+	}
+	index++
+	// length of remaining message
+	siglen := sigStr[index]
+	index++
+	if int(siglen+2) > len(sigStr) {
+		return nil, errors.New("malformed signature: bad length")
+	}
+	// trim the slice we're working on so we only look at what matters.
+	sigStr = sigStr[:siglen+2]
+
+	// 0x02
+	if sigStr[index] != 0x02 {
+		return nil,
+			errors.New("malformed signature: no 1st int marker")
+	}
+	index++
+
+	// Length of signature R.
+	rLen := int(sigStr[index])
+	// must be positive, must be able to fit in another 0x2, <len> <s>
+	// hence the -3. We assume that the length must be at least one byte.
+	index++
+	if rLen <= 0 || rLen > len(sigStr)-index-3 {
+		return nil, errors.New("malformed signature: bogus R length")
+	}
+
+	// Then R itself.
+	rBytes := sigStr[index : index+rLen]
+	if der {
+		switch err := canonicalPadding(rBytes); err {
+		case errNegativeValue:
+			return nil, errors.New("signature R is negative")
+		case errExcessivelyPaddedValue:
+			return nil, errors.New("signature R is excessively padded")
+		}
+	}
+	signature.R = new(big.Int).SetBytes(rBytes)
+	index += rLen
+	// 0x02. length already checked in previous if.
+	if sigStr[index] != 0x02 {
+		return nil, errors.New("malformed signature: no 2nd int marker")
+	}
+	index++
+
+	// Length of signature S.
+	sLen := int(sigStr[index])
+	index++
+	// S should be the rest of the string.
+	if sLen <= 0 || sLen > len(sigStr)-index {
+		return nil, errors.New("malformed signature: bogus S length")
+	}
+
+	// Then S itself.
+	sBytes := sigStr[index : index+sLen]
+	if der {
+		switch err := canonicalPadding(sBytes); err {
+		case errNegativeValue:
+			return nil, errors.New("signature S is negative")
+		case errExcessivelyPaddedValue:
+			return nil, errors.New("signature S is excessively padded")
+		}
+	}
+	signature.S = new(big.Int).SetBytes(sBytes)
+	index += sLen
+
+	// sanity check length parsing
+	if index != len(sigStr) {
+		return nil, fmt.Errorf("malformed signature: bad final length %v != %v",
+			index, len(sigStr))
+	}
+
+	// Verify also checks this, but we can be more sure that we parsed
+	// correctly if we verify here too.
+	// FWIW the ecdsa spec states that R and S must be | 1, N - 1 |
+	// but crypto/ecdsa only checks for Sign != 0. Mirror that.
+	if signature.R.Sign() != 1 {
+		return nil, errors.New("signature R isn't 1 or more")
+	}
+	if signature.S.Sign() != 1 {
+		return nil, errors.New("signature S isn't 1 or more")
+	}
+	if signature.R.Cmp(curve.Params().N) >= 0 {
+		return nil, errors.New("signature R is >= curve.N")
+	}
+	if signature.S.Cmp(curve.Params().N) >= 0 {
+		return nil, errors.New("signature S is >= curve.N")
+	}
+
+	return signature, nil
+}
+
+// ParseSignature parses a signature in BER format for the curve type `curve'
+// into a Signature type, perfoming some basic sanity checks.  If parsing
+// according to the more strict DER format is needed, use ParseDERSignature.
+func ParseSignature(sigStr []byte, curve elliptic.Curve) (*Signature, error) {
+	return parseSig(sigStr, curve, false)
+}
+
+// ParseDERSignature parses a signature in DER format for the curve type
+// `curve` into a Signature type.  If parsing according to the less strict
+// BER format is needed, use ParseSignature.
+func ParseDERSignature(sigStr []byte, curve elliptic.Curve) (*Signature, error) {
+	return parseSig(sigStr, curve, true)
+}
+
+// canonicalizeInt returns the bytes for the passed big integer adjusted as
+// necessary to ensure that a big-endian encoded integer can't possibly be
+// misinterpreted as a negative number.  This can happen when the most
+// significant bit is set, so it is padded by a leading zero byte in this case.
+// Also, the returned bytes will have at least a single byte when the passed
+// value is 0.  This is required for DER encoding.
+func canonicalizeInt(val *big.Int) []byte {
+	b := val.Bytes()
+	if len(b) == 0 {
+		b = []byte{0x00}
+	}
+	if b[0]&0x80 != 0 {
+		paddedBytes := make([]byte, len(b)+1)
+		copy(paddedBytes[1:], b)
+		b = paddedBytes
+	}
+	return b
+}
+
+// canonicalPadding checks whether a big-endian encoded integer could
+// possibly be misinterpreted as a negative number (even though OpenSSL
+// treats all numbers as unsigned), or if there is any unnecessary
+// leading zero padding.
+func canonicalPadding(b []byte) error {
+	switch {
+	case b[0]&0x80 == 0x80:
+		return errNegativeValue
+	case len(b) > 1 && b[0] == 0x00 && b[1]&0x80 != 0x80:
+		return errExcessivelyPaddedValue
+	default:
+		return nil
+	}
+}
+
+// hashToInt converts a hash value to an integer. There is some disagreement
+// about how this is done. [NSA] suggests that this is done in the obvious
+// manner, but [SECG] truncates the hash to the bit-length of the curve order
+// first. We follow [SECG] because that's what OpenSSL does. Additionally,
+// OpenSSL right shifts excess bits from the number if the hash is too large
+// and we mirror that too.
+// This is borrowed from crypto/ecdsa.
+func hashToInt(hash []byte, c elliptic.Curve) *big.Int {
+	orderBits := c.Params().N.BitLen()
+	orderBytes := (orderBits + 7) / 8
+	if len(hash) > orderBytes {
+		hash = hash[:orderBytes]
+	}
+
+	ret := new(big.Int).SetBytes(hash)
+	excess := len(hash)*8 - orderBits
+	if excess > 0 {
+		ret.Rsh(ret, uint(excess))
+	}
+	return ret
+}
+
+// recoverKeyFromSignature recoves a public key from the signature "sig" on the
+// given message hash "msg". Based on the algorithm found in section 5.1.5 of
+// SEC 1 Ver 2.0, page 47-48 (53 and 54 in the pdf). This performs the details
+// in the inner loop in Step 1. The counter provided is actually the j parameter
+// of the loop * 2 - on the first iteration of j we do the R case, else the -R
+// case in step 1.6. This counter is used in the bitcoin compressed signature
+// format and thus we match bitcoind's behaviour here.
+func recoverKeyFromSignature(curve *KoblitzCurve, sig *Signature, msg []byte,
+	iter int, doChecks bool) (*PublicKey, error) {
+	// 1.1 x = (n * i) + r
+	Rx := new(big.Int).Mul(curve.Params().N,
+		new(big.Int).SetInt64(int64(iter/2)))
+	Rx.Add(Rx, sig.R)
+	if Rx.Cmp(curve.Params().P) != -1 {
+		return nil, errors.New("calculated Rx is larger than curve P")
+	}
+
+	// convert 02<Rx> to point R. (step 1.2 and 1.3). If we are on an odd
+	// iteration then 1.6 will be done with -R, so we calculate the other
+	// term when uncompressing the point.
+	Ry, err := decompressPoint(curve, Rx, iter%2 == 1)
+	if err != nil {
+		return nil, err
+	}
+
+	// 1.4 Check n*R is point at infinity
+	if doChecks {
+		nRx, nRy := curve.ScalarMult(Rx, Ry, curve.Params().N.Bytes())
+		if nRx.Sign() != 0 || nRy.Sign() != 0 {
+			return nil, errors.New("n*R does not equal the point at infinity")
+		}
+	}
+
+	// 1.5 calculate e from message using the same algorithm as ecdsa
+	// signature calculation.
+	e := hashToInt(msg, curve)
+
+	// Step 1.6.1:
+	// We calculate the two terms sR and eG separately multiplied by the
+	// inverse of r (from the signature). We then add them to calculate
+	// Q = r^-1(sR-eG)
+	invr := new(big.Int).ModInverse(sig.R, curve.Params().N)
+
+	// first term.
+	invrS := new(big.Int).Mul(invr, sig.S)
+	invrS.Mod(invrS, curve.Params().N)
+	sRx, sRy := curve.ScalarMult(Rx, Ry, invrS.Bytes())
+
+	// second term.
+	e.Neg(e)
+	e.Mod(e, curve.Params().N)
+	e.Mul(e, invr)
+	e.Mod(e, curve.Params().N)
+	minuseGx, minuseGy := curve.ScalarBaseMult(e.Bytes())
+
+	// TODO: this would be faster if we did a mult and add in one
+	// step to prevent the jacobian conversion back and forth.
+	Qx, Qy := curve.Add(sRx, sRy, minuseGx, minuseGy)
+
+	return &PublicKey{
+		Curve: curve,
+		X:     Qx,
+		Y:     Qy,
+	}, nil
+}
+
+// SignCompact produces a compact signature of the data in hash with the given
+// private key on the given koblitz curve. The isCompressed  parameter should
+// be used to detail if the given signature should reference a compressed
+// public key or not. If successful the bytes of the compact signature will be
+// returned in the format:
+// <(byte of 27+public key solution)+4 if compressed >< padded bytes for signature R><padded bytes for signature S>
+// where the R and S parameters are padde up to the bitlengh of the curve.
+func SignCompact(curve *KoblitzCurve, key *PrivateKey,
+	hash []byte, isCompressedKey bool) ([]byte, error) {
+	sig, err := key.Sign(hash)
+	if err != nil {
+		return nil, err
+	}
+
+	// bitcoind checks the bit length of R and S here. The ecdsa signature
+	// algorithm returns R and S mod N therefore they will be the bitsize of
+	// the curve, and thus correctly sized.
+	for i := 0; i < (curve.H+1)*2; i++ {
+		pk, err := recoverKeyFromSignature(curve, sig, hash, i, true)
+		if err == nil && pk.X.Cmp(key.X) == 0 && pk.Y.Cmp(key.Y) == 0 {
+			result := make([]byte, 1, 2*curve.byteSize+1)
+			result[0] = 27 + byte(i)
+			if isCompressedKey {
+				result[0] += 4
+			}
+			// Not sure this needs rounding but safer to do so.
+			curvelen := (curve.BitSize + 7) / 8
+
+			// Pad R and S to curvelen if needed.
+			bytelen := (sig.R.BitLen() + 7) / 8
+			if bytelen < curvelen {
+				result = append(result,
+					make([]byte, curvelen-bytelen)...)
+			}
+			result = append(result, sig.R.Bytes()...)
+
+			bytelen = (sig.S.BitLen() + 7) / 8
+			if bytelen < curvelen {
+				result = append(result,
+					make([]byte, curvelen-bytelen)...)
+			}
+			result = append(result, sig.S.Bytes()...)
+
+			return result, nil
+		}
+	}
+
+	return nil, errors.New("no valid solution for pubkey found")
+}
+
+// RecoverCompact verifies the compact signature "signature" of "hash" for the
+// Koblitz curve in "curve". If the signature matches then the recovered public
+// key will be returned as well as a boolen if the original key was compressed
+// or not, else an error will be returned.
+func RecoverCompact(curve *KoblitzCurve, signature,
+	hash []byte) (*PublicKey, bool, error) {
+	bitlen := (curve.BitSize + 7) / 8
+	if len(signature) != 1+bitlen*2 {
+		return nil, false, errors.New("invalid compact signature size")
+	}
+
+	iteration := int((signature[0] - 27) & ^byte(4))
+
+	// format is <header byte><bitlen R><bitlen S>
+	sig := &Signature{
+		R: new(big.Int).SetBytes(signature[1 : bitlen+1]),
+		S: new(big.Int).SetBytes(signature[bitlen+1:]),
+	}
+	// The iteration used here was encoded
+	key, err := recoverKeyFromSignature(curve, sig, hash, iteration, false)
+	if err != nil {
+		return nil, false, err
+	}
+
+	return key, ((signature[0] - 27) & 4) == 4, nil
+}
+
+// signRFC6979 generates a deterministic ECDSA signature according to RFC 6979 and BIP 62.
+func signRFC6979(privateKey *PrivateKey, hash []byte) (*Signature, error) {
+
+	privkey := privateKey.ToECDSA()
+	N := order
+	k := nonceRFC6979(privkey.D, hash)
+	inv := new(big.Int).ModInverse(k, N)
+	r, _ := privkey.Curve.ScalarBaseMult(k.Bytes())
+	if r.Cmp(N) == 1 {
+		r.Sub(r, N)
+	}
+
+	if r.Sign() == 0 {
+		return nil, errors.New("calculated R is zero")
+	}
+
+	e := hashToInt(hash, privkey.Curve)
+	s := new(big.Int).Mul(privkey.D, r)
+	s.Add(s, e)
+	s.Mul(s, inv)
+	s.Mod(s, N)
+
+	if s.Cmp(halforder) == 1 {
+		s.Sub(N, s)
+	}
+	if s.Sign() == 0 {
+		return nil, errors.New("calculated S is zero")
+	}
+	return &Signature{R: r, S: s}, nil
+}
+
+// nonceRFC6979 generates an ECDSA nonce (`k`) deterministically according to RFC 6979.
+// It takes a 32-byte hash as an input and returns 32-byte nonce to be used in ECDSA algorithm.
+func nonceRFC6979(privkey *big.Int, hash []byte) *big.Int {
+
+	curve := S256()
+	q := curve.Params().N
+	x := privkey
+	alg := sha256.New
+
+	qlen := q.BitLen()
+	holen := alg().Size()
+	rolen := (qlen + 7) >> 3
+	bx := append(int2octets(x, rolen), bits2octets(hash, curve, rolen)...)
+
+	// Step B
+	v := bytes.Repeat(oneInitializer, holen)
+
+	// Step C (Go zeroes the all allocated memory)
+	k := make([]byte, holen)
+
+	// Step D
+	k = mac(alg, k, append(append(v, 0x00), bx...))
+
+	// Step E
+	v = mac(alg, k, v)
+
+	// Step F
+	k = mac(alg, k, append(append(v, 0x01), bx...))
+
+	// Step G
+	v = mac(alg, k, v)
+
+	// Step H
+	for {
+		// Step H1
+		var t []byte
+
+		// Step H2
+		for len(t)*8 < qlen {
+			v = mac(alg, k, v)
+			t = append(t, v...)
+		}
+
+		// Step H3
+		secret := hashToInt(t, curve)
+		if secret.Cmp(one) >= 0 && secret.Cmp(q) < 0 {
+			return secret
+		}
+		k = mac(alg, k, append(v, 0x00))
+		v = mac(alg, k, v)
+	}
+}
+
+// mac returns an HMAC of the given key and message.
+func mac(alg func() hash.Hash, k, m []byte) []byte {
+	h := hmac.New(alg, k)
+	h.Write(m)
+	return h.Sum(nil)
+}
+
+// https://tools.ietf.org/html/rfc6979#section-2.3.3
+func int2octets(v *big.Int, rolen int) []byte {
+	out := v.Bytes()
+
+	// left pad with zeros if it's too short
+	if len(out) < rolen {
+		out2 := make([]byte, rolen)
+		copy(out2[rolen-len(out):], out)
+		return out2
+	}
+
+	// drop most significant bytes if it's too long
+	if len(out) > rolen {
+		out2 := make([]byte, rolen)
+		copy(out2, out[len(out)-rolen:])
+		return out2
+	}
+
+	return out
+}
+
+// https://tools.ietf.org/html/rfc6979#section-2.3.4
+func bits2octets(in []byte, curve elliptic.Curve, rolen int) []byte {
+	z1 := hashToInt(in, curve)
+	z2 := new(big.Int).Sub(z1, curve.Params().N)
+	if z2.Sign() < 0 {
+		return int2octets(z1, rolen)
+	}
+	return int2octets(z2, rolen)
+}

vendor/github.com/karalabe/gousb/.gitignore

@@ -1 +0,0 @@
-*.sw[op]

vendor/github.com/karalabe/gousb/.travis.yml

@@ -1,12 +0,0 @@
-language: go
-
-matrix:
-  include:
-    - os: linux
-      dist: trusty
-      go: 1.7.4
-    - os: osx
-      go: 1.7.4
-
-script:
-  - go test -v -test.run='BCD|Parse' ./...

vendor/github.com/karalabe/gousb/LICENSE

@@ -1,202 +0,0 @@
-
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-                           Version 2.0, January 2004
-                        http://www.apache.org/licenses/
-
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vendor/github.com/karalabe/gousb/README.md

@@ -1,47 +0,0 @@
-Introduction
-============
-
-[![Travis Build Status][travisimg]][travis]
-[![AppVeyor Build Status][appveyorimg]][appveyor]
-[![GoDoc][docimg]][doc]
-
-The gousb package is an attempt at wrapping the `libusb` library into a Go-like binding in a fully self-contained, go-gettable package. Supported platforms include Linux, macOS and Windows as well as the mobile platforms Android and iOS.
-
-This package is a fork of [`github.com/kylelemons/gousb`](https://github.com/kylelemons/gousb), which at the moment seems to be unmaintained. The current fork is different from the upstream package as it contains code to embed `libusb` directly into the Go package (thus becoming fully self-cotnained and go-gettable), as well as it features a few contributions and bugfixes that never really got addressed in the upstream package, but which address important issues nonetheless.
-
-*Note, if @kylelemons decides to pick development of the upstream project up again, consider all commits made by me to this repo as ready contributions. I cannot vouch for other commits as the upstream repo needs a signed CLA for Google.*
-
-[travisimg]:   https://travis-ci.org/karalabe/gousb.svg?branch=master
-[travis]:      https://travis-ci.org/karalabe/gousb
-[appveyorimg]: https://ci.appveyor.com/api/projects/status/84k9xse10rl72gn2/branch/master?svg=true
-[appveyor]:    https://ci.appveyor.com/project/karalabe/gousb
-[docimg]:      https://godoc.org/github.com/karalabe/gousb?status.svg
-[doc]:         https://godoc.org/github.com/karalabe/gousb
-
-Installation
-============
-
-Example: lsusb
---------------
-The gousb project provides a simple but useful example: lsusb.  This binary will list the USB devices connected to your system and various interesting tidbits about them, their configurations, endpoints, etc.  To install it, run the following command:
-
-    go get -v github.com/karalabe/gousb/lsusb
-
-gousb
------
-If you installed the lsusb example, both libraries below are already installed.
-
-Installing the primary gousb package is really easy:
-
-    go get -v github.com/karalabe/gousb/usb
-
-There is also a `usbid` package that will not be installed by default by this command, but which provides useful information including the human-readable vendor and product codes for detected hardware.  It's not installed by default and not linked into the `usb` package by default because it adds ~400kb to the resulting binary.  If you want both, they can be installed thus:
-
-    go get -v github.com/karalabe/gousb/usb{,id}
-
-Documentation
-=============
-The documentation can be viewed via local godoc or via the excellent [godoc.org](http://godoc.org/):
-
-- [usb](http://godoc.org/github.com/karalabe/gousb/usb)
-- [usbid](http://godoc.org/pkg/github.com/karalabe/gousb/usbid)

vendor/github.com/karalabe/gousb/appveyor.yml

@@ -1,34 +0,0 @@
-os: Visual Studio 2015
-
-# Clone directly into GOPATH.
-clone_folder: C:\gopath\src\github.com\karalabe\gousb
-clone_depth: 5
-version: "{branch}.{build}"
-environment:
-  global:
-    GOPATH: C:\gopath
-    CC: gcc.exe
-  matrix:
-    - GOARCH: amd64
-      MSYS2_ARCH: x86_64
-      MSYS2_BITS: 64
-      MSYSTEM: MINGW64
-      PATH: C:\msys64\mingw64\bin\;%PATH%
-    - GOARCH: 386
-      MSYS2_ARCH: i686
-      MSYS2_BITS: 32
-      MSYSTEM: MINGW32
-      PATH: C:\msys64\mingw32\bin\;%PATH%
-
-install:
-  - rmdir C:\go /s /q
-  - appveyor DownloadFile https://storage.googleapis.com/golang/go1.7.4.windows-%GOARCH%.zip
-  - 7z x go1.7.4.windows-%GOARCH%.zip -y -oC:\ > NUL
-  - go version
-  - gcc --version
-
-build_script:
-  - go install ./...
-
-test_script:
-  - go test -v -test.run="BCD|Parse" ./...

vendor/github.com/karalabe/gousb/usb/config.go

@@ -1,153 +0,0 @@
-// Copyright 2013 Google Inc.  All rights reserved.
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//     http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
-
-package usb
-
-/*
-#ifndef OS_WINDOWS
-	#include "os/threads_posix.h"
-#endif
-#include "libusbi.h"
-#include "libusb.h"
-*/
-import "C"
-
-import (
-	"fmt"
-	"reflect"
-	"unsafe"
-)
-
-type EndpointInfo struct {
-	Address       uint8
-	Attributes    uint8
-	MaxPacketSize uint16
-	MaxIsoPacket  uint32
-	PollInterval  uint8
-	RefreshRate   uint8
-	SynchAddress  uint8
-}
-
-func (e EndpointInfo) Number() int {
-	return int(e.Address) & ENDPOINT_NUM_MASK
-}
-
-func (e EndpointInfo) Direction() EndpointDirection {
-	return EndpointDirection(e.Address) & ENDPOINT_DIR_MASK
-}
-
-func (e EndpointInfo) String() string {
-	return fmt.Sprintf("Endpoint %d %-3s %s - %s %s [%d %d]",
-		e.Number(), e.Direction(),
-		TransferType(e.Attributes)&TRANSFER_TYPE_MASK,
-		IsoSyncType(e.Attributes)&ISO_SYNC_TYPE_MASK,
-		IsoUsageType(e.Attributes)&ISO_USAGE_TYPE_MASK,
-		e.MaxPacketSize, e.MaxIsoPacket,
-	)
-}
-
-type InterfaceInfo struct {
-	Number uint8
-	Setups []InterfaceSetup
-}
-
-func (i InterfaceInfo) String() string {
-	return fmt.Sprintf("Interface %02x (%d setups)", i.Number, len(i.Setups))
-}
-
-type InterfaceSetup struct {
-	Number     uint8
-	Alternate  uint8
-	IfClass    uint8
-	IfSubClass uint8
-	IfProtocol uint8
-	Endpoints  []EndpointInfo
-}
-
-func (a InterfaceSetup) String() string {
-	return fmt.Sprintf("Interface %02x Setup %02x", a.Number, a.Alternate)
-}
-
-type ConfigInfo struct {
-	Config     uint8
-	Attributes uint8
-	MaxPower   uint8
-	Interfaces []InterfaceInfo
-}
-
-func (c ConfigInfo) String() string {
-	return fmt.Sprintf("Config %02x", c.Config)
-}
-
-func newConfig(dev *C.libusb_device, cfg *C.struct_libusb_config_descriptor) ConfigInfo {
-	c := ConfigInfo{
-		Config:     uint8(cfg.bConfigurationValue),
-		Attributes: uint8(cfg.bmAttributes),
-		MaxPower:   uint8(cfg.MaxPower),
-	}
-
-	var ifaces []C.struct_libusb_interface
-	*(*reflect.SliceHeader)(unsafe.Pointer(&ifaces)) = reflect.SliceHeader{
-		Data: uintptr(unsafe.Pointer(cfg._interface)),
-		Len:  int(cfg.bNumInterfaces),
-		Cap:  int(cfg.bNumInterfaces),
-	}
-	c.Interfaces = make([]InterfaceInfo, 0, len(ifaces))
-	for _, iface := range ifaces {
-		if iface.num_altsetting == 0 {
-			continue
-		}
-
-		var alts []C.struct_libusb_interface_descriptor
-		*(*reflect.SliceHeader)(unsafe.Pointer(&alts)) = reflect.SliceHeader{
-			Data: uintptr(unsafe.Pointer(iface.altsetting)),
-			Len:  int(iface.num_altsetting),
-			Cap:  int(iface.num_altsetting),
-		}
-		descs := make([]InterfaceSetup, 0, len(alts))
-		for _, alt := range alts {
-			i := InterfaceSetup{
-				Number:     uint8(alt.bInterfaceNumber),
-				Alternate:  uint8(alt.bAlternateSetting),
-				IfClass:    uint8(alt.bInterfaceClass),
-				IfSubClass: uint8(alt.bInterfaceSubClass),
-				IfProtocol: uint8(alt.bInterfaceProtocol),
-			}
-			var ends []C.struct_libusb_endpoint_descriptor
-			*(*reflect.SliceHeader)(unsafe.Pointer(&ends)) = reflect.SliceHeader{
-				Data: uintptr(unsafe.Pointer(alt.endpoint)),
-				Len:  int(alt.bNumEndpoints),
-				Cap:  int(alt.bNumEndpoints),
-			}
-			i.Endpoints = make([]EndpointInfo, 0, len(ends))
-			for _, end := range ends {
-				i.Endpoints = append(i.Endpoints, EndpointInfo{
-					Address:       uint8(end.bEndpointAddress),
-					Attributes:    uint8(end.bmAttributes),
-					MaxPacketSize: uint16(end.wMaxPacketSize),
-					//MaxIsoPacket:  uint32(C.libusb_get_max_iso_packet_size(dev, C.uchar(end.bEndpointAddress))),
-					PollInterval: uint8(end.bInterval),
-					RefreshRate:  uint8(end.bRefresh),
-					SynchAddress: uint8(end.bSynchAddress),
-				})
-			}
-			descs = append(descs, i)
-		}
-		c.Interfaces = append(c.Interfaces, InterfaceInfo{
-			Number: descs[0].Number,
-			Setups: descs,
-		})
-	}
-	return c
-}

vendor/github.com/karalabe/gousb/usb/constants.go

@@ -1,183 +0,0 @@
-// Copyright 2013 Google Inc.  All rights reserved.
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//     http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
-
-package usb
-
-// #include "libusb.h"
-import "C"
-
-type Class uint8
-
-const (
-	CLASS_PER_INTERFACE Class = C.LIBUSB_CLASS_PER_INTERFACE
-	CLASS_AUDIO         Class = C.LIBUSB_CLASS_AUDIO
-	CLASS_COMM          Class = C.LIBUSB_CLASS_COMM
-	CLASS_HID           Class = C.LIBUSB_CLASS_HID
-	CLASS_PRINTER       Class = C.LIBUSB_CLASS_PRINTER
-	CLASS_PTP           Class = C.LIBUSB_CLASS_PTP
-	CLASS_MASS_STORAGE  Class = C.LIBUSB_CLASS_MASS_STORAGE
-	CLASS_HUB           Class = C.LIBUSB_CLASS_HUB
-	CLASS_DATA          Class = C.LIBUSB_CLASS_DATA
-	CLASS_WIRELESS      Class = C.LIBUSB_CLASS_WIRELESS
-	CLASS_APPLICATION   Class = C.LIBUSB_CLASS_APPLICATION
-	CLASS_VENDOR_SPEC   Class = C.LIBUSB_CLASS_VENDOR_SPEC
-)
-
-var classDescription = map[Class]string{
-	CLASS_PER_INTERFACE: "per-interface",
-	CLASS_AUDIO:         "audio",
-	CLASS_COMM:          "communications",
-	CLASS_HID:           "human interface device",
-	CLASS_PRINTER:       "printer dclass",
-	CLASS_PTP:           "picture transfer protocol",
-	CLASS_MASS_STORAGE:  "mass storage",
-	CLASS_HUB:           "hub",
-	CLASS_DATA:          "data",
-	CLASS_WIRELESS:      "wireless",
-	CLASS_APPLICATION:   "application",
-	CLASS_VENDOR_SPEC:   "vendor-specific",
-}
-
-func (c Class) String() string {
-	return classDescription[c]
-}
-
-type DescriptorType uint8
-
-const (
-	DT_DEVICE    DescriptorType = C.LIBUSB_DT_DEVICE
-	DT_CONFIG    DescriptorType = C.LIBUSB_DT_CONFIG
-	DT_STRING    DescriptorType = C.LIBUSB_DT_STRING
-	DT_INTERFACE DescriptorType = C.LIBUSB_DT_INTERFACE
-	DT_ENDPOINT  DescriptorType = C.LIBUSB_DT_ENDPOINT
-	DT_HID       DescriptorType = C.LIBUSB_DT_HID
-	DT_REPORT    DescriptorType = C.LIBUSB_DT_REPORT
-	DT_PHYSICAL  DescriptorType = C.LIBUSB_DT_PHYSICAL
-	DT_HUB       DescriptorType = C.LIBUSB_DT_HUB
-)
-
-var descriptorTypeDescription = map[DescriptorType]string{
-	DT_DEVICE:    "device",
-	DT_CONFIG:    "configuration",
-	DT_STRING:    "string",
-	DT_INTERFACE: "interface",
-	DT_ENDPOINT:  "endpoint",
-	DT_HID:       "HID",
-	DT_REPORT:    "HID report",
-	DT_PHYSICAL:  "physical",
-	DT_HUB:       "hub",
-}
-
-func (dt DescriptorType) String() string {
-	return descriptorTypeDescription[dt]
-}
-
-type EndpointDirection uint8
-
-const (
-	ENDPOINT_NUM_MASK                   = 0x03
-	ENDPOINT_DIR_IN   EndpointDirection = C.LIBUSB_ENDPOINT_IN
-	ENDPOINT_DIR_OUT  EndpointDirection = C.LIBUSB_ENDPOINT_OUT
-	ENDPOINT_DIR_MASK EndpointDirection = 0x80
-)
-
-var endpointDirectionDescription = map[EndpointDirection]string{
-	ENDPOINT_DIR_IN:  "IN",
-	ENDPOINT_DIR_OUT: "OUT",
-}
-
-func (ed EndpointDirection) String() string {
-	return endpointDirectionDescription[ed]
-}
-
-type TransferType uint8
-
-const (
-	TRANSFER_TYPE_CONTROL     TransferType = C.LIBUSB_TRANSFER_TYPE_CONTROL
-	TRANSFER_TYPE_ISOCHRONOUS TransferType = C.LIBUSB_TRANSFER_TYPE_ISOCHRONOUS
-	TRANSFER_TYPE_BULK        TransferType = C.LIBUSB_TRANSFER_TYPE_BULK
-	TRANSFER_TYPE_INTERRUPT   TransferType = C.LIBUSB_TRANSFER_TYPE_INTERRUPT
-	TRANSFER_TYPE_MASK        TransferType = 0x03
-)
-
-var transferTypeDescription = map[TransferType]string{
-	TRANSFER_TYPE_CONTROL:     "control",
-	TRANSFER_TYPE_ISOCHRONOUS: "isochronous",
-	TRANSFER_TYPE_BULK:        "bulk",
-	TRANSFER_TYPE_INTERRUPT:   "interrupt",
-}
-
-func (tt TransferType) String() string {
-	return transferTypeDescription[tt]
-}
-
-type IsoSyncType uint8
-
-const (
-	ISO_SYNC_TYPE_NONE     IsoSyncType = C.LIBUSB_ISO_SYNC_TYPE_NONE << 2
-	ISO_SYNC_TYPE_ASYNC    IsoSyncType = C.LIBUSB_ISO_SYNC_TYPE_ASYNC << 2
-	ISO_SYNC_TYPE_ADAPTIVE IsoSyncType = C.LIBUSB_ISO_SYNC_TYPE_ADAPTIVE << 2
-	ISO_SYNC_TYPE_SYNC     IsoSyncType = C.LIBUSB_ISO_SYNC_TYPE_SYNC << 2
-	ISO_SYNC_TYPE_MASK     IsoSyncType = 0x0C
-)
-
-var isoSyncTypeDescription = map[IsoSyncType]string{
-	ISO_SYNC_TYPE_NONE:     "unsynchronized",
-	ISO_SYNC_TYPE_ASYNC:    "asynchronous",
-	ISO_SYNC_TYPE_ADAPTIVE: "adaptive",
-	ISO_SYNC_TYPE_SYNC:     "synchronous",
-}
-
-func (ist IsoSyncType) String() string {
-	return isoSyncTypeDescription[ist]
-}
-
-type IsoUsageType uint8
-
-const (
-	ISO_USAGE_TYPE_DATA     IsoUsageType = C.LIBUSB_ISO_USAGE_TYPE_DATA << 4
-	ISO_USAGE_TYPE_FEEDBACK IsoUsageType = C.LIBUSB_ISO_USAGE_TYPE_FEEDBACK << 4
-	ISO_USAGE_TYPE_IMPLICIT IsoUsageType = C.LIBUSB_ISO_USAGE_TYPE_IMPLICIT << 4
-	ISO_USAGE_TYPE_MASK     IsoUsageType = 0x30
-)
-
-var isoUsageTypeDescription = map[IsoUsageType]string{
-	ISO_USAGE_TYPE_DATA:     "data",
-	ISO_USAGE_TYPE_FEEDBACK: "feedback",
-	ISO_USAGE_TYPE_IMPLICIT: "implicit data",
-}
-
-func (iut IsoUsageType) String() string {
-	return isoUsageTypeDescription[iut]
-}
-
-type RequestType uint8
-
-const (
-	REQUEST_TYPE_STANDARD = C.LIBUSB_REQUEST_TYPE_STANDARD
-	REQUEST_TYPE_CLASS    = C.LIBUSB_REQUEST_TYPE_CLASS
-	REQUEST_TYPE_VENDOR   = C.LIBUSB_REQUEST_TYPE_VENDOR
-	REQUEST_TYPE_RESERVED = C.LIBUSB_REQUEST_TYPE_RESERVED
-)
-
-var requestTypeDescription = map[RequestType]string{
-	REQUEST_TYPE_STANDARD: "standard",
-	REQUEST_TYPE_CLASS:    "class",
-	REQUEST_TYPE_VENDOR:   "vendor",
-	REQUEST_TYPE_RESERVED: "reserved",
-}
-
-func (rt RequestType) String() string {
-	return requestTypeDescription[rt]
-}

vendor/github.com/karalabe/gousb/usb/debug.go

@@ -1,36 +0,0 @@
-// Copyright 2013 Google Inc.  All rights reserved.
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//     http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
-
-package usb
-
-// To enable internal debugging:
-//   -ldflags "-X github.com/karalabe/gousb/usb.debugInternal true"
-
-import (
-	"io"
-	"io/ioutil"
-	"log" // TODO(kevlar): make a logger
-	"os"
-)
-
-var debug *log.Logger
-var debugInternal string
-
-func init() {
-	var out io.Writer = ioutil.Discard
-	if debugInternal != "" {
-		out = os.Stderr
-	}
-	debug = log.New(out, "usb", log.LstdFlags|log.Lshortfile)
-}

vendor/github.com/karalabe/gousb/usb/descriptor.go

@@ -1,77 +0,0 @@
-// Copyright 2013 Google Inc.  All rights reserved.
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//     http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
-
-package usb
-
-/*
-#ifndef OS_WINDOWS
-	#include "os/threads_posix.h"
-#endif
-#include "libusbi.h"
-#include "libusb.h"
-*/
-import "C"
-
-type Descriptor struct {
-	// Bus information
-	Bus     uint8 // The bus on which the device was detected
-	Address uint8 // The address of the device on the bus
-
-	// Version information
-	Spec   BCD // USB Specification Release Number
-	Device BCD // The device version
-
-	// Product information
-	Vendor  ID // The Vendor identifer
-	Product ID // The Product identifier
-
-	// Protocol information
-	Class    uint8 // The class of this device
-	SubClass uint8 // The sub-class (within the class) of this device
-	Protocol uint8 // The protocol (within the sub-class) of this device
-
-	// Configuration information
-	Configs []ConfigInfo
-}
-
-func newDescriptor(dev *C.libusb_device) (*Descriptor, error) {
-	var desc C.struct_libusb_device_descriptor
-	if errno := C.libusb_get_device_descriptor(dev, &desc); errno < 0 {
-		return nil, usbError(errno)
-	}
-
-	// Enumerate configurations
-	var cfgs []ConfigInfo
-	for i := 0; i < int(desc.bNumConfigurations); i++ {
-		var cfg *C.struct_libusb_config_descriptor
-		if errno := C.libusb_get_config_descriptor(dev, C.uint8_t(i), &cfg); errno < 0 {
-			return nil, usbError(errno)
-		}
-		cfgs = append(cfgs, newConfig(dev, cfg))
-		C.libusb_free_config_descriptor(cfg)
-	}
-
-	return &Descriptor{
-		Bus:      uint8(C.libusb_get_bus_number(dev)),
-		Address:  uint8(C.libusb_get_device_address(dev)),
-		Spec:     BCD(desc.bcdUSB),
-		Device:   BCD(desc.bcdDevice),
-		Vendor:   ID(desc.idVendor),
-		Product:  ID(desc.idProduct),
-		Class:    uint8(desc.bDeviceClass),
-		SubClass: uint8(desc.bDeviceSubClass),
-		Protocol: uint8(desc.bDeviceProtocol),
-		Configs:  cfgs,
-	}, nil
-}

vendor/github.com/karalabe/gousb/usb/device.go

@@ -1,295 +0,0 @@
-// Copyright 2013 Google Inc.  All rights reserved.
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//     http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
-
-package usb
-
-/*
-#ifndef OS_WINDOWS
-	#include "os/threads_posix.h"
-#endif
-#include "libusbi.h"
-#include "libusb.h"
-*/
-import "C"
-
-import (
-	"fmt"
-	"reflect"
-	"sync"
-	"time"
-	"unsafe"
-)
-
-var DefaultReadTimeout = 1 * time.Second
-var DefaultWriteTimeout = 1 * time.Second
-var DefaultControlTimeout = 250 * time.Millisecond //5 * time.Second
-
-type Device struct {
-	handle *C.libusb_device_handle
-
-	// Embed the device information for easy access
-	*Descriptor
-
-	// Timeouts
-	ReadTimeout    time.Duration
-	WriteTimeout   time.Duration
-	ControlTimeout time.Duration
-
-	// Claimed interfaces
-	lock    *sync.Mutex
-	claimed map[uint8]int
-
-	// Detached kernel interfaces
-	detached map[uint8]int
-}
-
-func newDevice(handle *C.libusb_device_handle, desc *Descriptor) (*Device, error) {
-	ifaces := 0
-	d := &Device{
-		handle:         handle,
-		Descriptor:     desc,
-		ReadTimeout:    DefaultReadTimeout,
-		WriteTimeout:   DefaultWriteTimeout,
-		ControlTimeout: DefaultControlTimeout,
-		lock:           new(sync.Mutex),
-		claimed:        make(map[uint8]int, ifaces),
-		detached:       make(map[uint8]int),
-	}
-
-	if err := d.detachKernelDriver(); err != nil {
-		d.Close()
-		return nil, err
-	}
-
-	return d, nil
-}
-
-// detachKernelDriver detaches any active kernel drivers, if supported by the platform.
-// If there are any errors, like Context.ListDevices, only the final one will be returned.
-func (d *Device) detachKernelDriver() (err error) {
-	for _, cfg := range d.Configs {
-		for _, iface := range cfg.Interfaces {
-			switch activeErr := C.libusb_kernel_driver_active(d.handle, C.int(iface.Number)); activeErr {
-			case C.LIBUSB_ERROR_NOT_SUPPORTED:
-				// no need to do any futher checking, no platform support
-				return
-			case 0:
-				continue
-			case 1:
-				switch detachErr := C.libusb_detach_kernel_driver(d.handle, C.int(iface.Number)); detachErr {
-				case C.LIBUSB_ERROR_NOT_SUPPORTED:
-					// shouldn't ever get here, should be caught by the outer switch
-					return
-				case 0:
-					d.detached[iface.Number]++
-				case C.LIBUSB_ERROR_NOT_FOUND:
-					// this status is returned if libusb's driver is already attached to the device
-					d.detached[iface.Number]++
-				default:
-					err = fmt.Errorf("usb: detach kernel driver: %s", usbError(detachErr))
-				}
-			default:
-				err = fmt.Errorf("usb: active kernel driver check: %s", usbError(activeErr))
-			}
-		}
-	}
-
-	return
-}
-
-// attachKernelDriver re-attaches kernel drivers to any previously detached interfaces, if supported by the platform.
-// If there are any errors, like Context.ListDevices, only the final one will be returned.
-func (d *Device) attachKernelDriver() (err error) {
-	for iface := range d.detached {
-		switch attachErr := C.libusb_attach_kernel_driver(d.handle, C.int(iface)); attachErr {
-		case C.LIBUSB_ERROR_NOT_SUPPORTED:
-			// no need to do any futher checking, no platform support
-			return
-		case 0:
-			continue
-		default:
-			err = fmt.Errorf("usb: attach kernel driver: %s", usbError(attachErr))
-		}
-	}
-
-	return
-}
-
-func (d *Device) Reset() error {
-	if errno := C.libusb_reset_device(d.handle); errno != 0 {
-		return usbError(errno)
-	}
-	return nil
-}
-
-func (d *Device) Control(rType, request uint8, val, idx uint16, data []byte) (int, error) {
-	//log.Printf("control xfer: %d:%d/%d:%d %x", idx, rType, request, val, string(data))
-	dataSlice := (*reflect.SliceHeader)(unsafe.Pointer(&data))
-	n := C.libusb_control_transfer(
-		d.handle,
-		C.uint8_t(rType),
-		C.uint8_t(request),
-		C.uint16_t(val),
-		C.uint16_t(idx),
-		(*C.uchar)(unsafe.Pointer(dataSlice.Data)),
-		C.uint16_t(len(data)),
-		C.uint(d.ControlTimeout/time.Millisecond))
-	if n < 0 {
-		return int(n), usbError(n)
-	}
-	return int(n), nil
-}
-
-// ActiveConfig returns the config id (not the index) of the active configuration.
-// This corresponds to the ConfigInfo.Config field.
-func (d *Device) ActiveConfig() (uint8, error) {
-	var cfg C.int
-	if errno := C.libusb_get_configuration(d.handle, &cfg); errno < 0 {
-		return 0, usbError(errno)
-	}
-	return uint8(cfg), nil
-}
-
-// SetConfig attempts to change the active configuration.
-// The cfg provided is the config id (not the index) of the configuration to set,
-// which corresponds to the ConfigInfo.Config field.
-func (d *Device) SetConfig(cfg uint8) error {
-	if errno := C.libusb_set_configuration(d.handle, C.int(cfg)); errno < 0 {
-		return usbError(errno)
-	}
-	return nil
-}
-
-// Close the device.
-func (d *Device) Close() error {
-	if d.handle == nil {
-		return fmt.Errorf("usb: double close on device")
-	}
-	d.lock.Lock()
-	defer d.lock.Unlock()
-	for iface := range d.claimed {
-		C.libusb_release_interface(d.handle, C.int(iface))
-	}
-	d.attachKernelDriver()
-	C.libusb_close(d.handle)
-	d.handle = nil
-	return nil
-}
-
-func (d *Device) OpenEndpoint(conf, iface, setup, epoint uint8) (Endpoint, error) {
-	end := &endpoint{
-		Device: d,
-	}
-
-	var setAlternate bool
-	for _, c := range d.Configs {
-		if c.Config != conf {
-			continue
-		}
-		debug.Printf("found conf: %#v\n", c)
-		for _, i := range c.Interfaces {
-			if i.Number != iface {
-				continue
-			}
-			debug.Printf("found iface: %#v\n", i)
-			for i, s := range i.Setups {
-				if s.Alternate != setup {
-					continue
-				}
-				setAlternate = i != 0
-
-				debug.Printf("found setup: %#v [default: %v]\n", s, !setAlternate)
-				for _, e := range s.Endpoints {
-					debug.Printf("ep %02x search: %#v\n", epoint, s)
-					if e.Address != epoint {
-						continue
-					}
-					end.InterfaceSetup = s
-					end.EndpointInfo = e
-					switch tt := TransferType(e.Attributes) & TRANSFER_TYPE_MASK; tt {
-					case TRANSFER_TYPE_BULK:
-						end.xfer = bulk_xfer
-					case TRANSFER_TYPE_INTERRUPT:
-						end.xfer = interrupt_xfer
-					case TRANSFER_TYPE_ISOCHRONOUS:
-						end.xfer = isochronous_xfer
-					default:
-						return nil, fmt.Errorf("usb: %s transfer is unsupported", tt)
-					}
-					goto found
-				}
-				return nil, fmt.Errorf("usb: unknown endpoint %02x", epoint)
-			}
-			return nil, fmt.Errorf("usb: unknown setup %02x", setup)
-		}
-		return nil, fmt.Errorf("usb: unknown interface %02x", iface)
-	}
-	return nil, fmt.Errorf("usb: unknown configuration %02x", conf)
-
-found:
-
-	// Set the configuration
-	var activeConf C.int
-	if errno := C.libusb_get_configuration(d.handle, &activeConf); errno < 0 {
-		return nil, fmt.Errorf("usb: getcfg: %s", usbError(errno))
-	}
-	if int(activeConf) != int(conf) {
-		if errno := C.libusb_set_configuration(d.handle, C.int(conf)); errno < 0 {
-			return nil, fmt.Errorf("usb: setcfg: %s", usbError(errno))
-		}
-	}
-
-	// Claim the interface
-	if errno := C.libusb_claim_interface(d.handle, C.int(iface)); errno < 0 {
-		return nil, fmt.Errorf("usb: claim: %s", usbError(errno))
-	}
-
-	// Increment the claim count
-	d.lock.Lock()
-	d.claimed[iface]++
-	d.lock.Unlock() // unlock immediately because the next calls may block
-
-	// Choose the alternate
-	if setAlternate {
-		if errno := C.libusb_set_interface_alt_setting(d.handle, C.int(iface), C.int(setup)); errno < 0 {
-			debug.Printf("altsetting error: %s", usbError(errno))
-			return nil, fmt.Errorf("usb: setalt: %s", usbError(errno))
-		}
-	}
-
-	return end, nil
-}
-
-func (d *Device) GetStringDescriptor(desc_index int) (string, error) {
-
-	// allocate 200-byte array limited the length of string descriptor
-	goBuffer := make([]byte, 200)
-
-	// get string descriptor from libusb. if errno < 0 then there are any errors.
-	// if errno >= 0; it is a length of result string descriptor
-	errno := C.libusb_get_string_descriptor_ascii(
-		d.handle,
-		C.uint8_t(desc_index),
-		(*C.uchar)(unsafe.Pointer(&goBuffer[0])),
-		200)
-
-	// if any errors occur
-	if errno < 0 {
-		return "", fmt.Errorf("usb: getstr: %s", usbError(errno))
-	}
-	// convert slice of byte to string with limited length from errno
-	stringDescriptor := string(goBuffer[:errno])
-
-	return stringDescriptor, nil
-}

vendor/github.com/karalabe/gousb/usb/endpoint.go

@@ -1,100 +0,0 @@
-// Copyright 2013 Google Inc.  All rights reserved.
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//     http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
-
-package usb
-
-// #include "libusb.h"
-import "C"
-
-import (
-	"fmt"
-	"reflect"
-	"time"
-	"unsafe"
-)
-
-type Endpoint interface {
-	Read(b []byte) (int, error)
-	Write(b []byte) (int, error)
-	Interface() InterfaceSetup
-	Info() EndpointInfo
-}
-
-type endpoint struct {
-	*Device
-	InterfaceSetup
-	EndpointInfo
-	xfer func(*endpoint, []byte, time.Duration) (int, error)
-}
-
-func (e *endpoint) Read(buf []byte) (int, error) {
-	if EndpointDirection(e.Address)&ENDPOINT_DIR_MASK != ENDPOINT_DIR_IN {
-		return 0, fmt.Errorf("usb: read: not an IN endpoint")
-	}
-
-	return e.xfer(e, buf, e.ReadTimeout)
-}
-
-func (e *endpoint) Write(buf []byte) (int, error) {
-	if EndpointDirection(e.Address)&ENDPOINT_DIR_MASK != ENDPOINT_DIR_OUT {
-		return 0, fmt.Errorf("usb: write: not an OUT endpoint")
-	}
-
-	return e.xfer(e, buf, e.WriteTimeout)
-}
-
-func (e *endpoint) Interface() InterfaceSetup { return e.InterfaceSetup }
-func (e *endpoint) Info() EndpointInfo        { return e.EndpointInfo }
-
-// TODO(kevlar): (*Endpoint).Close
-
-func bulk_xfer(e *endpoint, buf []byte, timeout time.Duration) (int, error) {
-	if len(buf) == 0 {
-		return 0, nil
-	}
-
-	data := (*reflect.SliceHeader)(unsafe.Pointer(&buf)).Data
-
-	var cnt C.int
-	if errno := C.libusb_bulk_transfer(
-		e.handle,
-		C.uchar(e.Address),
-		(*C.uchar)(unsafe.Pointer(data)),
-		C.int(len(buf)),
-		&cnt,
-		C.uint(timeout/time.Millisecond)); errno < 0 {
-		return 0, usbError(errno)
-	}
-	return int(cnt), nil
-}
-
-func interrupt_xfer(e *endpoint, buf []byte, timeout time.Duration) (int, error) {
-	if len(buf) == 0 {
-		return 0, nil
-	}
-
-	data := (*reflect.SliceHeader)(unsafe.Pointer(&buf)).Data
-
-	var cnt C.int
-	if errno := C.libusb_interrupt_transfer(
-		e.handle,
-		C.uchar(e.Address),
-		(*C.uchar)(unsafe.Pointer(data)),
-		C.int(len(buf)),
-		&cnt,
-		C.uint(timeout/time.Millisecond)); errno < 0 {
-		return 0, usbError(errno)
-	}
-	return int(cnt), nil
-}

vendor/github.com/karalabe/gousb/usb/error.go

@@ -1,92 +0,0 @@
-// Copyright 2013 Google Inc.  All rights reserved.
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//     http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
-
-package usb
-
-import (
-	"fmt"
-)
-
-// #include "libusb.h"
-import "C"
-
-type usbError C.int
-
-func (e usbError) Error() string {
-	return fmt.Sprintf("libusb: %s [code %d]", usbErrorString[e], int(e))
-}
-
-const (
-	SUCCESS             usbError = C.LIBUSB_SUCCESS
-	ERROR_IO            usbError = C.LIBUSB_ERROR_IO
-	ERROR_INVALID_PARAM usbError = C.LIBUSB_ERROR_INVALID_PARAM
-	ERROR_ACCESS        usbError = C.LIBUSB_ERROR_ACCESS
-	ERROR_NO_DEVICE     usbError = C.LIBUSB_ERROR_NO_DEVICE
-	ERROR_NOT_FOUND     usbError = C.LIBUSB_ERROR_NOT_FOUND
-	ERROR_BUSY          usbError = C.LIBUSB_ERROR_BUSY
-	ERROR_TIMEOUT       usbError = C.LIBUSB_ERROR_TIMEOUT
-	ERROR_OVERFLOW      usbError = C.LIBUSB_ERROR_OVERFLOW
-	ERROR_PIPE          usbError = C.LIBUSB_ERROR_PIPE
-	ERROR_INTERRUPTED   usbError = C.LIBUSB_ERROR_INTERRUPTED
-	ERROR_NO_MEM        usbError = C.LIBUSB_ERROR_NO_MEM
-	ERROR_NOT_SUPPORTED usbError = C.LIBUSB_ERROR_NOT_SUPPORTED
-	ERROR_OTHER         usbError = C.LIBUSB_ERROR_OTHER
-)
-
-var usbErrorString = map[usbError]string{
-	C.LIBUSB_SUCCESS:             "success",
-	C.LIBUSB_ERROR_IO:            "i/o error",
-	C.LIBUSB_ERROR_INVALID_PARAM: "invalid param",
-	C.LIBUSB_ERROR_ACCESS:        "bad access",
-	C.LIBUSB_ERROR_NO_DEVICE:     "no device",
-	C.LIBUSB_ERROR_NOT_FOUND:     "not found",
-	C.LIBUSB_ERROR_BUSY:          "device or resource busy",
-	C.LIBUSB_ERROR_TIMEOUT:       "timeout",
-	C.LIBUSB_ERROR_OVERFLOW:      "overflow",
-	C.LIBUSB_ERROR_PIPE:          "pipe error",
-	C.LIBUSB_ERROR_INTERRUPTED:   "interrupted",
-	C.LIBUSB_ERROR_NO_MEM:        "out of memory",
-	C.LIBUSB_ERROR_NOT_SUPPORTED: "not supported",
-	C.LIBUSB_ERROR_OTHER:         "unknown error",
-}
-
-type TransferStatus uint8
-
-const (
-	LIBUSB_TRANSFER_COMPLETED TransferStatus = C.LIBUSB_TRANSFER_COMPLETED
-	LIBUSB_TRANSFER_ERROR     TransferStatus = C.LIBUSB_TRANSFER_ERROR
-	LIBUSB_TRANSFER_TIMED_OUT TransferStatus = C.LIBUSB_TRANSFER_TIMED_OUT
-	LIBUSB_TRANSFER_CANCELLED TransferStatus = C.LIBUSB_TRANSFER_CANCELLED
-	LIBUSB_TRANSFER_STALL     TransferStatus = C.LIBUSB_TRANSFER_STALL
-	LIBUSB_TRANSFER_NO_DEVICE TransferStatus = C.LIBUSB_TRANSFER_NO_DEVICE
-	LIBUSB_TRANSFER_OVERFLOW  TransferStatus = C.LIBUSB_TRANSFER_OVERFLOW
-)
-
-var transferStatusDescription = map[TransferStatus]string{
-	LIBUSB_TRANSFER_COMPLETED: "transfer completed without error",
-	LIBUSB_TRANSFER_ERROR:     "transfer failed",
-	LIBUSB_TRANSFER_TIMED_OUT: "transfer timed out",
-	LIBUSB_TRANSFER_CANCELLED: "transfer was cancelled",
-	LIBUSB_TRANSFER_STALL:     "halt condition detected (endpoint stalled) or control request not supported",
-	LIBUSB_TRANSFER_NO_DEVICE: "device was disconnected",
-	LIBUSB_TRANSFER_OVERFLOW:  "device sent more data than requested",
-}
-
-func (ts TransferStatus) String() string {
-	return transferStatusDescription[ts]
-}
-
-func (ts TransferStatus) Error() string {
-	return "libusb: " + ts.String()
-}

vendor/github.com/karalabe/gousb/usb/iso.c

@@ -1,79 +0,0 @@
-#include "libusb.h"
-#include <stdio.h>
-#include <string.h>
-
-void print_xfer(struct libusb_transfer *xfer);
-void iso_callback(void *);
-
-void callback(struct libusb_transfer *xfer) {
-	//printf("Callback!\n");
-	//print_xfer(xfer);
-	iso_callback(xfer->user_data);
-}
-
-int submit(struct libusb_transfer *xfer) {
-	xfer->callback = &callback;
-	xfer->status = -1;
-	//print_xfer(xfer);
-	//printf("Transfer submitted\n");
-
-	/* fake
-	strcpy(xfer->buffer, "hello");
-	xfer->actual_length = 5;
-	callback(xfer);
-	return 0; */
-	return libusb_submit_transfer(xfer);
-}
-
-void print_xfer(struct libusb_transfer *xfer) {
-	int i;
-
-	printf("Transfer:\n");
-	printf("  dev_handle:   %p\n", xfer->dev_handle);
-	printf("  flags:        %08x\n", xfer->flags);
-	printf("  endpoint:     %x\n", xfer->endpoint);
-	printf("  type:         %x\n", xfer->type);
-	printf("  timeout:      %dms\n", xfer->timeout);
-	printf("  status:       %x\n", xfer->status);
-	printf("  length:       %d (act: %d)\n", xfer->length, xfer->actual_length);
-	printf("  callback:     %p\n", xfer->callback);
-	printf("  user_data:    %p\n", xfer->user_data);
-	printf("  buffer:       %p\n", xfer->buffer);
-	printf("  num_iso_pkts: %d\n", xfer->num_iso_packets);
-	printf("  packets:\n");
-	for (i = 0; i < xfer->num_iso_packets; i++) {
-		printf("    [%04d] %d (act: %d) %x\n", i,
-			xfer->iso_packet_desc[i].length,
-			xfer->iso_packet_desc[i].actual_length,
-			xfer->iso_packet_desc[i].status);
-	}
-}
-
-int extract_data(struct libusb_transfer *xfer, void *raw, int max, unsigned char *status) {
-	int i;
-	int copied = 0;
-	unsigned char *in = xfer->buffer;
-	unsigned char *out = raw;
-	for (i = 0; i < xfer->num_iso_packets; i++) {
-		struct libusb_iso_packet_descriptor pkt = xfer->iso_packet_desc[i];
-
-		// Copy the data
-		int len = pkt.actual_length;
-		if (len > max) {
-			len = max;
-		}
-		memcpy(out, in, len);
-		copied += len;
-
-		// Increment offsets
-		in += pkt.length;
-		out += len;
-
-		// Extract first error
-		if (pkt.status == 0 || *status != 0) {
-			continue;
-		}
-		*status = pkt.status;
-	}
-	return copied;
-}

vendor/github.com/karalabe/gousb/usb/iso.go

@@ -1,148 +0,0 @@
-// Copyright 2013 Google Inc.  All rights reserved.
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//     http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
-
-package usb
-
-/*
-#include "libusb.h"
-
-int submit(struct libusb_transfer *xfer);
-void print_xfer(struct libusb_transfer *xfer);
-int extract_data(struct libusb_transfer *xfer, void *data, int max, unsigned char *status);
-*/
-import "C"
-
-import (
-	"fmt"
-	"log"
-	"time"
-	"unsafe"
-)
-
-//export iso_callback
-func iso_callback(cptr unsafe.Pointer) {
-	ch := *(*chan struct{})(cptr)
-	close(ch)
-}
-
-func (end *endpoint) allocTransfer() *Transfer {
-	// Use libusb_get_max_iso_packet_size ?
-	const (
-		iso_packets = 8       // 128 // 242
-		packet_size = 2 * 960 // 1760
-	)
-
-	xfer := C.libusb_alloc_transfer(C.int(iso_packets))
-	if xfer == nil {
-		log.Printf("usb: transfer allocation failed?!")
-		return nil
-	}
-
-	buf := make([]byte, iso_packets*packet_size)
-	done := make(chan struct{}, 1)
-
-	xfer.dev_handle = end.Device.handle
-	xfer.endpoint = C.uchar(end.Address)
-	xfer._type = C.LIBUSB_TRANSFER_TYPE_ISOCHRONOUS
-
-	xfer.buffer = (*C.uchar)((unsafe.Pointer)(&buf[0]))
-	xfer.length = C.int(len(buf))
-	xfer.num_iso_packets = iso_packets
-
-	C.libusb_set_iso_packet_lengths(xfer, packet_size)
-	/*
-		pkts := *(*[]C.struct_libusb_packet_descriptor)(unsafe.Pointer(&reflect.SliceHeader{
-			Data: uintptr(unsafe.Pointer(&xfer.iso_packet_desc)),
-			Len:  iso_packets,
-			Cap:  iso_packets,
-		}))
-	*/
-
-	t := &Transfer{
-		xfer: xfer,
-		done: done,
-		buf:  buf,
-	}
-	xfer.user_data = (unsafe.Pointer)(&t.done)
-
-	return t
-}
-
-type Transfer struct {
-	xfer *C.struct_libusb_transfer
-	pkts []*C.struct_libusb_packet_descriptor
-	done chan struct{}
-	buf  []byte
-}
-
-func (t *Transfer) Submit(timeout time.Duration) error {
-	//log.Printf("iso: submitting %#v", t.xfer)
-	t.xfer.timeout = C.uint(timeout / time.Millisecond)
-	if errno := C.submit(t.xfer); errno < 0 {
-		return usbError(errno)
-	}
-	return nil
-}
-
-func (t *Transfer) Wait(b []byte) (n int, err error) {
-	select {
-	case <-time.After(10 * time.Second):
-		return 0, fmt.Errorf("wait timed out after 10s")
-	case <-t.done:
-	}
-	// Non-iso transfers:
-	//n = int(t.xfer.actual_length)
-	//copy(b, ((*[1 << 16]byte)(unsafe.Pointer(t.xfer.buffer)))[:n])
-
-	//C.print_xfer(t.xfer)
-	/*
-		buf, offset := ((*[1 << 16]byte)(unsafe.Pointer(t.xfer.buffer))), 0
-		for i, pkt := range *t.pkts {
-			log.Printf("Type is %T", t.pkts)
-			n += copy(b[n:], buf[offset:][:pkt.actual_length])
-			offset += pkt.Length
-			if pkt.status != 0 && err == nil {
-				err = error(TransferStatus(pkt.status))
-			}
-		}
-	*/
-	var status uint8
-	n = int(C.extract_data(t.xfer, unsafe.Pointer(&b[0]), C.int(len(b)), (*C.uchar)(unsafe.Pointer(&status))))
-	if status != 0 {
-		err = TransferStatus(status)
-	}
-	return n, err
-}
-
-func (t *Transfer) Close() error {
-	C.libusb_free_transfer(t.xfer)
-	return nil
-}
-
-func isochronous_xfer(e *endpoint, buf []byte, timeout time.Duration) (int, error) {
-	t := e.allocTransfer()
-	defer t.Close()
-
-	if err := t.Submit(timeout); err != nil {
-		log.Printf("iso: xfer failed to submit: %s", err)
-		return 0, err
-	}
-
-	n, err := t.Wait(buf)
-	if err != nil {
-		log.Printf("iso: xfer failed: %s", err)
-		return 0, err
-	}
-	return n, err
-}

vendor/github.com/karalabe/gousb/usb/misc.go

@@ -1,47 +0,0 @@
-// Copyright 2013 Google Inc.  All rights reserved.
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//     http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
-
-package usb
-
-import (
-	"fmt"
-)
-
-type BCD uint16
-
-const (
-	USB_2_0 BCD = 0x0200
-	USB_1_1 BCD = 0x0110
-	USB_1_0 BCD = 0x0100
-)
-
-func (d BCD) Int() (i int) {
-	ten := 1
-	for o := uint(0); o < 4; o++ {
-		n := ((0xF << (o * 4)) & d) >> (o * 4)
-		i += int(n) * ten
-		ten *= 10
-	}
-	return
-}
-
-func (d BCD) String() string {
-	return fmt.Sprintf("%02x.%02x", int(d>>8), int(d&0xFF))
-}
-
-type ID uint16
-
-func (id ID) String() string {
-	return fmt.Sprintf("%04x", int(id))
-}

vendor/github.com/karalabe/gousb/usb/usb.go

@@ -1,178 +0,0 @@
-// Copyright 2013 Google Inc.  All rights reserved.
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//     http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
-
-// Package usb provides a wrapper around libusb-1.0.
-package usb
-
-/*
-#cgo CFLAGS: -I../internal/libusb/libusb
-#cgo CFLAGS: -DDEFAULT_VISIBILITY=""
-#cgo linux CFLAGS: -DOS_LINUX -D_GNU_SOURCE -DPOLL_NFDS_TYPE=int
-#cgo darwin CFLAGS: -DOS_DARWIN -DPOLL_NFDS_TYPE=int
-#cgo darwin LDFLAGS: -framework CoreFoundation -framework IOKit -lobjc
-#cgo openbsd CFLAGS: -DOS_OPENBSD -DPOLL_NFDS_TYPE=int
-#cgo windows CFLAGS: -DOS_WINDOWS -DUSE_USBDK -DPOLL_NFDS_TYPE=int
-
-#if defined(OS_LINUX) || defined(OS_DARWIN) || defined(OS_OPENBSD)
-	#include <sys/poll.h>
-	#include "os/threads_posix.c"
-	#include "os/poll_posix.c"
-#elif defined(OS_WINDOWS)
-	#include "os/threads_windows.c"
-	#include "os/poll_windows.c"
-#endif
-
-#ifdef OS_LINUX
-	#include "os/linux_usbfs.c"
-	#include "os/linux_netlink.c"
-#elif OS_DARWIN
-	#include "os/darwin_usb.c"
-#elif OS_OPENBSD
-	#include "os/openbsd_usb.c"
-#elif OS_WINDOWS
-	#include "os/windows_nt_common.c"
-	#include "os/windows_usbdk.c"
-#endif
-
-#include "core.c"
-#include "descriptor.c"
-#include "hotplug.c"
-#include "io.c"
-#include "strerror.c"
-#include "sync.c"
-*/
-import "C"
-
-import (
-	"log"
-	"reflect"
-	"unsafe"
-)
-
-type Context struct {
-	ctx  *C.libusb_context
-	done chan struct{}
-}
-
-func (c *Context) Debug(level int) {
-	C.libusb_set_debug(c.ctx, C.int(level))
-}
-
-func NewContext() (*Context, error) {
-	c := &Context{
-		done: make(chan struct{}),
-	}
-
-	if errno := C.libusb_init(&c.ctx); errno != 0 {
-		return nil, usbError(errno)
-	}
-
-	go func() {
-		tv := C.struct_timeval{
-			tv_sec:  0,
-			tv_usec: 100000,
-		}
-		for {
-			select {
-			case <-c.done:
-				return
-			default:
-			}
-			if errno := C.libusb_handle_events_timeout_completed(c.ctx, &tv, nil); errno < 0 {
-				log.Printf("handle_events: error: %s", usbError(errno))
-				continue
-			}
-			//log.Printf("handle_events returned")
-		}
-	}()
-
-	return c, nil
-}
-
-// ListDevices calls each with each enumerated device.
-// If the function returns true, the device is opened and a Device is returned if the operation succeeds.
-// Every Device returned (whether an error is also returned or not) must be closed.
-// If there are any errors enumerating the devices,
-// the final one is returned along with any successfully opened devices.
-func (c *Context) ListDevices(each func(desc *Descriptor) bool) ([]*Device, error) {
-	var list **C.libusb_device
-	cnt := C.libusb_get_device_list(c.ctx, &list)
-	if cnt < 0 {
-		return nil, usbError(cnt)
-	}
-	defer C.libusb_free_device_list(list, 1)
-
-	var slice []*C.libusb_device
-	*(*reflect.SliceHeader)(unsafe.Pointer(&slice)) = reflect.SliceHeader{
-		Data: uintptr(unsafe.Pointer(list)),
-		Len:  int(cnt),
-		Cap:  int(cnt),
-	}
-
-	var reterr error
-	var ret []*Device
-	for _, dev := range slice {
-		desc, err := newDescriptor(dev)
-		if err != nil {
-			reterr = err
-			continue
-		}
-
-		if each(desc) {
-			var handle *C.libusb_device_handle
-			if errno := C.libusb_open(dev, &handle); errno != 0 {
-				reterr = usbError(errno)
-				continue
-			}
-			if dev, err := newDevice(handle, desc); err != nil {
-				reterr = err
-			} else {
-				ret = append(ret, dev)
-			}
-		}
-	}
-	return ret, reterr
-}
-
-// OpenDeviceWithVidPid opens Device from specific VendorId and ProductId.
-// If there are any errors, it'll returns at second value.
-func (c *Context) OpenDeviceWithVidPid(vid, pid int) (*Device, error) {
-
-	handle := C.libusb_open_device_with_vid_pid(c.ctx, (C.uint16_t)(vid), (C.uint16_t)(pid))
-	if handle == nil {
-		return nil, ERROR_NOT_FOUND
-	}
-
-	dev := C.libusb_get_device(handle)
-	if dev == nil {
-		return nil, ERROR_NO_DEVICE
-	}
-
-	desc, err := newDescriptor(dev)
-
-	// return an error from nil-handle and nil-device
-	if err != nil {
-		return nil, err
-	}
-	return newDevice(handle, desc)
-}
-
-func (c *Context) Close() error {
-	close(c.done)
-	if c.ctx != nil {
-		C.libusb_exit(c.ctx)
-	}
-	c.ctx = nil
-	return nil
-}

vendor/github.com/karalabe/hid/LICENSE.md

@@ -0,0 +1,8 @@
+The components of `hid` are licensed as such:
+
+ * `hidapi` is released under the [3-clause BSD](https://github.com/signal11/hidapi/blob/master/LICENSE-bsd.txt) license.
+ * `libusb` is released under the [GNU GPL 2.1](https://github.com/libusb/libusb/blob/master/COPYING)license.
+ * `go.hid` is released under the [2-clause BSD](https://github.com/GeertJohan/go.hid/blob/master/LICENSE) license.
+ * `gowchar` is released under the [3-clause BSD](https://github.com/orofarne/gowchar/blob/master/LICENSE) license.
+
+Given the above, `hid` is licensed under GNU GPL 2.1 or later on Linux and 3-clause BSD on other platforms.

vendor/github.com/karalabe/hid/README.md

@@ -0,0 +1,41 @@
+[![GoDoc][docimg]][docurl]
+
+[docimg]: https://godoc.org/github.com/karalabe/hid?status.svg
+[docurl]: https://godoc.org/github.com/karalabe/hid
+
+# Gopher Interface Devices (USB HID)
+
+The `hid` package is a cross platform library for accessing and communicating with USB Human Interface
+Devices (HID). It is an alternative package to [`gousb`](https://github.com/karalabe/gousb) for use
+cases where devices support this ligher mode of operation (e.g. input devices, hardware crypto wallets).
+
+The package wraps [`hidapi`](https://github.com/signal11/hidapi) for accessing OS specific USB HID APIs
+directly instead of using low level USB constructs, which might have permission issues on some platforms.
+On Linux the package also wraps [`libusb`](https://github.com/libusb/libusb). Both of these dependencies
+are vendored directly into the repository and wrapped using CGO, making the `hid` package self-contained
+and go-gettable.
+
+Supported platforms at the moment are Linux, macOS and Windows (exclude constraints are also specified
+for Android and iOS to allow smoother vendoring into cross platform projects).
+
+## Acknowledgements
+
+Although the `hid` package is an implementation from scratch, it was heavily inspired by the existing
+[`go.hid`](https://github.com/GeertJohan/go.hid) library, which seems abandoned since 2015; is incompatible
+with Go 1.6+; and has various external dependencies. Given its inspirational roots, I thought it important
+to give credit to the author of said package too.
+
+Wide character support in the `hid` package is done via the [`gowchar`](https://github.com/orofarne/gowchar)
+library, unmaintained since 2013; non buildable with a modern Go release and failing `go vet` checks. As
+such, `gowchar` was also vendored in inline (copyright headers and origins preserved).
+
+## License
+
+The components of `hid` are licensed as such:
+
+ * `hidapi` is released under the [3-clause BSD](https://github.com/signal11/hidapi/blob/master/LICENSE-bsd.txt) license.
+ * `libusb` is released under the [GNU GPL 2.1](https://github.com/libusb/libusb/blob/master/COPYING)license.
+ * `go.hid` is released under the [2-clause BSD](https://github.com/GeertJohan/go.hid/blob/master/LICENSE) license.
+ * `gowchar` is released under the [3-clause BSD](https://github.com/orofarne/gowchar/blob/master/LICENSE) license.
+
+Given the above, `hid` is licensed under GNU GPL 2.1 or later on Linux and 3-clause BSD on other platforms.

vendor/github.com/karalabe/hid/hid.go

@@ -0,0 +1,37 @@
+// hid - Gopher Interface Devices (USB HID)
+// Copyright (c) 2017 Péter Szilágyi. All rights reserved.
+//
+// This file is released under the 3-clause BSD license. Note however that Linux
+// support depends on libusb, released under GNU GPL 2.1 or later.
+
+// Package hid provides an interface for USB HID devices.
+package hid
+
+import "errors"
+
+// ErrDeviceClosed is returned for operations where the device closed before or
+// during the execution.
+var ErrDeviceClosed = errors.New("hid: device closed")
+
+// ErrUnsupportedPlatform is returned for all operations where the underlying
+// operating system is not supported by the library.
+var ErrUnsupportedPlatform = errors.New("hid: unsupported platform")
+
+// DeviceInfo is a hidapi info structure.
+type DeviceInfo struct {
+	Path         string // Platform-specific device path
+	VendorID     uint16 // Device Vendor ID
+	ProductID    uint16 // Device Product ID
+	Release      uint16 // Device Release Number in binary-coded decimal, also known as Device Version Number
+	Serial       string // Serial Number
+	Manufacturer string // Manufacturer String
+	Product      string // Product string
+	UsagePage    uint16 // Usage Page for this Device/Interface (Windows/Mac only)
+	Usage        uint16 // Usage for this Device/Interface (Windows/Mac only)
+
+	// The USB interface which this logical device
+	// represents. Valid on both Linux implementations
+	// in all cases, and valid on the Windows implementation
+	// only if the device contains more than one interface.
+	Interface int
+}

vendor/github.com/karalabe/hid/hid_disabled.go

@@ -0,0 +1,53 @@
+// hid - Gopher Interface Devices (USB HID)
+// Copyright (c) 2017 Péter Szilágyi. All rights reserved.
+//
+// This file is released under the 3-clause BSD license. Note however that Linux
+// support depends on libusb, released under GNU GPL 2.1 or later.
+
+// +build !linux
+// +build !darwin ios
+// +build !windows
+
+package hid
+
+// Supported returns whether this platform is supported by the HID library or not.
+// The goal of this method is to allow programatically handling platforms that do
+// not support USB HID and not having to fall back to build constraints.
+func Supported() bool {
+	return false
+}
+
+// Enumerate returns a list of all the HID devices attached to the system which
+// match the vendor and product id. On platforms that this file implements the
+// function is a noop and returns an empty list always.
+func Enumerate(vendorID uint16, productID uint16) []DeviceInfo {
+	return nil
+}
+
+// Device is a live HID USB connected device handle. On platforms that this file
+// implements the type lacks the actual HID device and all methods are noop.
+type Device struct {
+	DeviceInfo // Embed the infos for easier access
+}
+
+// Open connects to an HID device by its path name. On platforms that this file
+// implements the method just returns an error.
+func (info DeviceInfo) Open() (*Device, error) {
+	return nil, ErrUnsupportedPlatform
+}
+
+// Close releases the HID USB device handle. On platforms that this file implements
+// the method is just a noop.
+func (dev *Device) Close() {}
+
+// Write sends an output report to a HID device. On platforms that this file
+// implements the method just returns an error.
+func (dev *Device) Write(b []byte) (int, error) {
+	return 0, ErrUnsupportedPlatform
+}
+
+// Read retrieves an input report from a HID device. On platforms that this file
+// implements the method just returns an error.
+func (dev *Device) Read(b []byte) (int, error) {
+	return 0, ErrUnsupportedPlatform
+}

vendor/github.com/karalabe/hid/hid_enabled.go

@@ -0,0 +1,216 @@
+// hid - Gopher Interface Devices (USB HID)
+// Copyright (c) 2017 Péter Szilágyi. All rights reserved.
+//
+// This file is released under the 3-clause BSD license. Note however that Linux
+// support depends on libusb, released under GNU GPL 2.1 or later.
+
+// +build !ios
+// +build linux darwin windows
+
+package hid
+
+/*
+#cgo CFLAGS: -I./hidapi/hidapi
+
+#cgo linux CFLAGS: -I./libusb/libusb -DDEFAULT_VISIBILITY="" -DOS_LINUX -D_GNU_SOURCE -DPOLL_NFDS_TYPE=int
+#cgo darwin CFLAGS: -DOS_DARWIN
+#cgo darwin LDFLAGS: -framework CoreFoundation -framework IOKit
+#cgo windows CFLAGS: -DOS_WINDOWS
+#cgo windows LDFLAGS: -lsetupapi
+
+#ifdef OS_LINUX
+	#include <sys/poll.h>
+	#include "os/threads_posix.c"
+	#include "os/poll_posix.c"
+
+	#include "os/linux_usbfs.c"
+	#include "os/linux_netlink.c"
+
+	#include "core.c"
+	#include "descriptor.c"
+	#include "hotplug.c"
+	#include "io.c"
+	#include "strerror.c"
+	#include "sync.c"
+
+	#include "hidapi/libusb/hid.c"
+#elif OS_DARWIN
+	#include "hidapi/mac/hid.c"
+#elif OS_WINDOWS
+	#include "hidapi/windows/hid.c"
+#endif
+*/
+import "C"
+import (
+	"errors"
+	"runtime"
+	"sync"
+	"unsafe"
+)
+
+func init() {
+	// Initialize the HIDAPI library
+	C.hid_init()
+}
+
+// Supported returns whether this platform is supported by the HID library or not.
+// The goal of this method is to allow programatically handling platforms that do
+// not support USB HID and not having to fall back to build constraints.
+func Supported() bool {
+	return true
+}
+
+// Enumerate returns a list of all the HID devices attached to the system which
+// match the vendor and product id:
+//  - If the vendor id is set to 0 then any vendor matches.
+//  - If the product id is set to 0 then any product matches.
+//  - If the vendor and product id are both 0, all HID devices are returned.
+func Enumerate(vendorID uint16, productID uint16) []DeviceInfo {
+	// Gather all device infos and ensure they are freed before returning
+	head := C.hid_enumerate(C.ushort(vendorID), C.ushort(productID))
+	if head == nil {
+		return nil
+	}
+	defer C.hid_free_enumeration(head)
+
+	// Iterate the list and retrieve the device details
+	var infos []DeviceInfo
+	for ; head != nil; head = head.next {
+		info := DeviceInfo{
+			Path:      C.GoString(head.path),
+			VendorID:  uint16(head.vendor_id),
+			ProductID: uint16(head.product_id),
+			Release:   uint16(head.release_number),
+			UsagePage: uint16(head.usage_page),
+			Usage:     uint16(head.usage),
+			Interface: int(head.interface_number),
+		}
+		if head.serial_number != nil {
+			info.Serial, _ = wcharTToString(head.serial_number)
+		}
+		if head.product_string != nil {
+			info.Product, _ = wcharTToString(head.product_string)
+		}
+		if head.manufacturer_string != nil {
+			info.Manufacturer, _ = wcharTToString(head.manufacturer_string)
+		}
+		infos = append(infos, info)
+	}
+	return infos
+}
+
+// Open connects to an HID device by its path name.
+func (info DeviceInfo) Open() (*Device, error) {
+	path := C.CString(info.Path)
+	defer C.free(unsafe.Pointer(path))
+
+	device := C.hid_open_path(path)
+	if device == nil {
+		return nil, errors.New("hidapi: failed to open device")
+	}
+	return &Device{
+		DeviceInfo: info,
+		device:     device,
+	}, nil
+}
+
+// Device is a live HID USB connected device handle.
+type Device struct {
+	DeviceInfo // Embed the infos for easier access
+
+	device *C.hid_device // Low level HID device to communicate through
+	lock   sync.Mutex
+}
+
+// Close releases the HID USB device handle.
+func (dev *Device) Close() {
+	dev.lock.Lock()
+	defer dev.lock.Unlock()
+
+	if dev.device != nil {
+		C.hid_close(dev.device)
+		dev.device = nil
+	}
+}
+
+// Write sends an output report to a HID device.
+//
+// Write will send the data on the first OUT endpoint, if one exists. If it does
+// not, it will send the data through the Control Endpoint (Endpoint 0).
+func (dev *Device) Write(b []byte) (int, error) {
+	// Abort if nothing to write
+	if len(b) == 0 {
+		return 0, nil
+	}
+	// Abort if device closed in between
+	dev.lock.Lock()
+	device := dev.device
+	dev.lock.Unlock()
+
+	if device == nil {
+		return 0, ErrDeviceClosed
+	}
+	// Prepend a HID report ID on Windows, other OSes don't need it
+	var report []byte
+	if runtime.GOOS == "windows" {
+		report = append([]byte{0x00}, b...)
+	} else {
+		report = b
+	}
+	// Execute the write operation
+	written := int(C.hid_write(device, (*C.uchar)(&report[0]), C.size_t(len(report))))
+	if written == -1 {
+		// If the write failed, verify if closed or other error
+		dev.lock.Lock()
+		device = dev.device
+		dev.lock.Unlock()
+
+		if device == nil {
+			return 0, ErrDeviceClosed
+		}
+		// Device not closed, some other error occurred
+		message := C.hid_error(device)
+		if message == nil {
+			return 0, errors.New("hidapi: unknown failure")
+		}
+		failure, _ := wcharTToString(message)
+		return 0, errors.New("hidapi: " + failure)
+	}
+	return written, nil
+}
+
+// Read retrieves an input report from a HID device.
+func (dev *Device) Read(b []byte) (int, error) {
+	// Aborth if nothing to read
+	if len(b) == 0 {
+		return 0, nil
+	}
+	// Abort if device closed in between
+	dev.lock.Lock()
+	device := dev.device
+	dev.lock.Unlock()
+
+	if device == nil {
+		return 0, ErrDeviceClosed
+	}
+	// Execute the read operation
+	read := int(C.hid_read(device, (*C.uchar)(&b[0]), C.size_t(len(b))))
+	if read == -1 {
+		// If the read failed, verify if closed or other error
+		dev.lock.Lock()
+		device = dev.device
+		dev.lock.Unlock()
+
+		if device == nil {
+			return 0, ErrDeviceClosed
+		}
+		// Device not closed, some other error occurred
+		message := C.hid_error(device)
+		if message == nil {
+			return 0, errors.New("hidapi: unknown failure")
+		}
+		failure, _ := wcharTToString(message)
+		return 0, errors.New("hidapi: " + failure)
+	}
+	return read, nil
+}

vendor/github.com/karalabe/hid/hidapi/AUTHORS.txt

@@ -0,0 +1,16 @@
+
+HIDAPI Authors:
+
+Alan Ott <alan@signal11.us>:
+	Original Author and Maintainer
+	Linux, Windows, and Mac implementations
+
+Ludovic Rousseau <rousseau@debian.org>:
+	Formatting for Doxygen documentation
+	Bug fixes
+	Correctness fixes
+
+
+For a comprehensive list of contributions, see the commit list at github:
+	http://github.com/signal11/hidapi/commits/master
+

vendor/github.com/karalabe/hid/hidapi/LICENSE-bsd.txt

@@ -0,0 +1,26 @@
+Copyright (c) 2010, Alan Ott, Signal 11 Software
+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.
+    * Neither the name of Signal 11 Software nor the names of its
+      contributors may be used to endorse or promote products derived from
+      this software without specific prior written permission.
+
+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/karalabe/hid/hidapi/LICENSE-gpl3.txt

@@ -0,0 +1,674 @@
+                    GNU GENERAL PUBLIC LICENSE
+                       Version 3, 29 June 2007
+
+ Copyright (C) 2007 Free Software Foundation, Inc. <http://fsf.org/>
+ Everyone is permitted to copy and distribute verbatim copies
+ of this license document, but changing it is not allowed.
+
+                            Preamble
+
+  The GNU General Public License is a free, copyleft license for
+software and other kinds of works.
+
+  The licenses for most software and other practical works are designed
+to take away your freedom to share and change the works.  By contrast,
+the GNU General Public License is intended to guarantee your freedom to
+share and change all versions of a program--to make sure it remains free
+software for all its users.  We, the Free Software Foundation, use the
+GNU General Public License for most of our software; it applies also to
+any other work released this way by its authors.  You can apply it to
+your programs, too.
+
+  When we speak of free software, we are referring to freedom, not
+price.  Our General Public Licenses are designed to make sure that you
+have the freedom to distribute copies of free software (and charge for
+them if you wish), that you receive source code or can get it if you
+want it, that you can change the software or use pieces of it in new
+free programs, and that you know you can do these things.
+
+  To protect your rights, we need to prevent others from denying you
+these rights or asking you to surrender the rights.  Therefore, you have
+certain responsibilities if you distribute copies of the software, or if
+you modify it: responsibilities to respect the freedom of others.
+
+  For example, if you distribute copies of such a program, whether
+gratis or for a fee, you must pass on to the recipients the same
+freedoms that you received.  You must make sure that they, too, receive
+or can get the source code.  And you must show them these terms so they
+know their rights.
+
+  Developers that use the GNU GPL protect your rights with two steps:
+(1) assert copyright on the software, and (2) offer you this License
+giving you legal permission to copy, distribute and/or modify it.
+
+  For the developers' and authors' protection, the GPL clearly explains
+that there is no warranty for this free software.  For both users' and
+authors' sake, the GPL requires that modified versions be marked as
+changed, so that their problems will not be attributed erroneously to
+authors of previous versions.
+
+  Some devices are designed to deny users access to install or run
+modified versions of the software inside them, although the manufacturer
+can do so.  This is fundamentally incompatible with the aim of
+protecting users' freedom to change the software.  The systematic
+pattern of such abuse occurs in the area of products for individuals to
+use, which is precisely where it is most unacceptable.  Therefore, we
+have designed this version of the GPL to prohibit the practice for those
+products.  If such problems arise substantially in other domains, we
+stand ready to extend this provision to those domains in future versions
+of the GPL, as needed to protect the freedom of users.
+
+  Finally, every program is threatened constantly by software patents.
+States should not allow patents to restrict development and use of
+software on general-purpose computers, but in those that do, we wish to
+avoid the special danger that patents applied to a free program could
+make it effectively proprietary.  To prevent this, the GPL assures that
+patents cannot be used to render the program non-free.
+
+  The precise terms and conditions for copying, distribution and
+modification follow.
+
+                       TERMS AND CONDITIONS
+
+  0. Definitions.
+
+  "This License" refers to version 3 of the GNU General Public License.
+
+  "Copyright" also means copyright-like laws that apply to other kinds of
+works, such as semiconductor masks.
+
+  "The Program" refers to any copyrightable work licensed under this
+License.  Each licensee is addressed as "you".  "Licensees" and
+"recipients" may be individuals or organizations.
+
+  To "modify" a work means to copy from or adapt all or part of the work
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vendor/github.com/karalabe/hid/hidapi/LICENSE-orig.txt

@@ -0,0 +1,9 @@
+ HIDAPI - Multi-Platform library for
+ communication with HID devices.
+
+ Copyright 2009, Alan Ott, Signal 11 Software.
+ All Rights Reserved.
+ 
+ This software may be used by anyone for any reason so
+ long as the copyright notice in the source files
+ remains intact.

vendor/github.com/karalabe/hid/hidapi/LICENSE.txt

@@ -0,0 +1,13 @@
+HIDAPI can be used under one of three licenses.
+
+1. The GNU General Public License, version 3.0, in LICENSE-gpl3.txt
+2. A BSD-Style License, in LICENSE-bsd.txt.
+3. The more liberal original HIDAPI license. LICENSE-orig.txt
+
+The license chosen is at the discretion of the user of HIDAPI. For example:
+1. An author of GPL software would likely use HIDAPI under the terms of the
+GPL.
+
+2. An author of commercial closed-source software would likely use HIDAPI
+under the terms of the BSD-style license or the original HIDAPI license.
+

vendor/github.com/karalabe/hid/hidapi/README.txt

@@ -0,0 +1,339 @@
+         HIDAPI library for Windows, Linux, FreeBSD and Mac OS X
+        =========================================================
+
+About
+======
+
+HIDAPI is a multi-platform library which allows an application to interface
+with USB and Bluetooth HID-Class devices on Windows, Linux, FreeBSD, and Mac
+OS X.  HIDAPI can be either built as a shared library (.so or .dll) or
+can be embedded directly into a target application by adding a single source
+file (per platform) and a single header.
+
+HIDAPI has four back-ends:
+	* Windows (using hid.dll)
+	* Linux/hidraw (using the Kernel's hidraw driver)
+	* Linux/libusb (using libusb-1.0)
+	* FreeBSD (using libusb-1.0)
+	* Mac (using IOHidManager)
+
+On Linux, either the hidraw or the libusb back-end can be used. There are
+tradeoffs, and the functionality supported is slightly different.
+
+Linux/hidraw (linux/hid.c):
+This back-end uses the hidraw interface in the Linux kernel.  While this
+back-end will support both USB and Bluetooth, it has some limitations on
+kernels prior to 2.6.39, including the inability to send or receive feature
+reports.  In addition, it will only communicate with devices which have
+hidraw nodes associated with them.  Keyboards, mice, and some other devices
+which are blacklisted from having hidraw nodes will not work. Fortunately,
+for nearly all the uses of hidraw, this is not a problem.
+
+Linux/FreeBSD/libusb (libusb/hid.c):
+This back-end uses libusb-1.0 to communicate directly to a USB device. This
+back-end will of course not work with Bluetooth devices.
+
+HIDAPI also comes with a Test GUI. The Test GUI is cross-platform and uses
+Fox Toolkit (http://www.fox-toolkit.org).  It will build on every platform
+which HIDAPI supports.  Since it relies on a 3rd party library, building it
+is optional but recommended because it is so useful when debugging hardware.
+
+What Does the API Look Like?
+=============================
+The API provides the the most commonly used HID functions including sending
+and receiving of input, output, and feature reports.  The sample program,
+which communicates with a heavily hacked up version of the Microchip USB
+Generic HID sample looks like this (with error checking removed for
+simplicity):
+
+#ifdef WIN32
+#include <windows.h>
+#endif
+#include <stdio.h>
+#include <stdlib.h>
+#include "hidapi.h"
+
+#define MAX_STR 255
+
+int main(int argc, char* argv[])
+{
+	int res;
+	unsigned char buf[65];
+	wchar_t wstr[MAX_STR];
+	hid_device *handle;
+	int i;
+
+	// Initialize the hidapi library
+	res = hid_init();
+
+	// Open the device using the VID, PID,
+	// and optionally the Serial number.
+	handle = hid_open(0x4d8, 0x3f, NULL);
+
+	// Read the Manufacturer String
+	res = hid_get_manufacturer_string(handle, wstr, MAX_STR);
+	wprintf(L"Manufacturer String: %s\n", wstr);
+
+	// Read the Product String
+	res = hid_get_product_string(handle, wstr, MAX_STR);
+	wprintf(L"Product String: %s\n", wstr);
+
+	// Read the Serial Number String
+	res = hid_get_serial_number_string(handle, wstr, MAX_STR);
+	wprintf(L"Serial Number String: (%d) %s\n", wstr[0], wstr);
+
+	// Read Indexed String 1
+	res = hid_get_indexed_string(handle, 1, wstr, MAX_STR);
+	wprintf(L"Indexed String 1: %s\n", wstr);
+
+	// Toggle LED (cmd 0x80). The first byte is the report number (0x0).
+	buf[0] = 0x0;
+	buf[1] = 0x80;
+	res = hid_write(handle, buf, 65);
+
+	// Request state (cmd 0x81). The first byte is the report number (0x0).
+	buf[0] = 0x0;
+	buf[1] = 0x81;
+	res = hid_write(handle, buf, 65);
+
+	// Read requested state
+	res = hid_read(handle, buf, 65);
+
+	// Print out the returned buffer.
+	for (i = 0; i < 4; i++)
+		printf("buf[%d]: %d\n", i, buf[i]);
+
+	// Finalize the hidapi library
+	res = hid_exit();
+
+	return 0;
+}
+
+If you have your own simple test programs which communicate with standard
+hardware development boards (such as those from Microchip, TI, Atmel,
+FreeScale and others), please consider sending me something like the above
+for inclusion into the HIDAPI source.  This will help others who have the
+same hardware as you do.
+
+License
+========
+HIDAPI may be used by one of three licenses as outlined in LICENSE.txt.
+
+Download
+=========
+HIDAPI can be downloaded from github
+	git clone git://github.com/signal11/hidapi.git
+
+Build Instructions
+===================
+
+This section is long. Don't be put off by this. It's not long because it's
+complicated to build HIDAPI; it's quite the opposite.  This section is long
+because of the flexibility of HIDAPI and the large number of ways in which
+it can be built and used.  You will likely pick a single build method.
+
+HIDAPI can be built in several different ways. If you elect to build a
+shared library, you will need to build it from the HIDAPI source
+distribution.  If you choose instead to embed HIDAPI directly into your
+application, you can skip the building and look at the provided platform
+Makefiles for guidance.  These platform Makefiles are located in linux/
+libusb/ mac/ and windows/ and are called Makefile-manual.  In addition,
+Visual Studio projects are provided.  Even if you're going to embed HIDAPI
+into your project, it is still beneficial to build the example programs.
+
+
+Prerequisites:
+---------------
+
+	Linux:
+	-------
+	On Linux, you will need to install development packages for libudev,
+	libusb and optionally Fox-toolkit (for the test GUI). On
+	Debian/Ubuntu systems these can be installed by running:
+	    sudo apt-get install libudev-dev libusb-1.0-0-dev libfox-1.6-dev
+
+	If you downloaded the source directly from the git repository (using
+	git clone), you'll need Autotools:
+	    sudo apt-get install autotools-dev autoconf automake libtool
+
+	FreeBSD:
+	---------
+	On FreeBSD you will need to install GNU make, libiconv, and
+	optionally Fox-Toolkit (for the test GUI). This is done by running
+	the following:
+	    pkg_add -r gmake libiconv fox16
+
+	If you downloaded the source directly from the git repository (using
+	git clone), you'll need Autotools:
+	    pkg_add -r autotools
+
+	Mac:
+	-----
+	On Mac, you will need to install Fox-Toolkit if you wish to build
+	the Test GUI. There are two ways to do this, and each has a slight
+	complication. Which method you use depends on your use case.
+
+	If you wish to build the Test GUI just for your own testing on your
+	own computer, then the easiest method is to install Fox-Toolkit
+	using ports:
+		sudo port install fox
+
+	If you wish to build the TestGUI app bundle to redistribute to
+	others, you will need to install Fox-toolkit from source.  This is
+	because the version of fox that gets installed using ports uses the
+	ports X11 libraries which are not compatible with the Apple X11
+	libraries.  If you install Fox with ports and then try to distribute
+	your built app bundle, it will simply fail to run on other systems.
+	To install Fox-Toolkit manually, download the source package from
+	http://www.fox-toolkit.org, extract it, and run the following from
+	within the extracted source:
+		./configure && make && make install
+
+	Windows:
+	---------
+	On Windows, if you want to build the test GUI, you will need to get
+	the hidapi-externals.zip package from the download site.  This
+	contains pre-built binaries for Fox-toolkit.  Extract
+	hidapi-externals.zip just outside of hidapi, so that
+	hidapi-externals and hidapi are on the same level, as shown:
+
+	     Parent_Folder
+	       |
+	       +hidapi
+	       +hidapi-externals
+
+	Again, this step is not required if you do not wish to build the
+	test GUI.
+
+
+Building HIDAPI into a shared library on Unix Platforms:
+---------------------------------------------------------
+
+On Unix-like systems such as Linux, FreeBSD, Mac, and even Windows, using
+Mingw or Cygwin, the easiest way to build a standard system-installed shared
+library is to use the GNU Autotools build system.  If you checked out the
+source from the git repository, run the following:
+
+	./bootstrap
+	./configure
+	make
+	make install     <----- as root, or using sudo
+
+If you downloaded a source package (ie: if you did not run git clone), you
+can skip the ./bootstrap step.
+
+./configure can take several arguments which control the build. The two most
+likely to be used are:
+	--enable-testgui
+		Enable build of the Test GUI. This requires Fox toolkit to
+		be installed.  Instructions for installing Fox-Toolkit on
+		each platform are in the Prerequisites section above.
+
+	--prefix=/usr
+		Specify where you want the output headers and libraries to
+		be installed. The example above will put the headers in
+		/usr/include and the binaries in /usr/lib. The default is to
+		install into /usr/local which is fine on most systems.
+
+Building the manual way on Unix platforms:
+-------------------------------------------
+
+Manual Makefiles are provided mostly to give the user and idea what it takes
+to build a program which embeds HIDAPI directly inside of it. These should
+really be used as examples only. If you want to build a system-wide shared
+library, use the Autotools method described above.
+
+	To build HIDAPI using the manual makefiles, change to the directory
+	of your platform and run make. For example, on Linux run:
+		cd linux/
+		make -f Makefile-manual
+
+	To build the Test GUI using the manual makefiles:
+		cd testgui/
+		make -f Makefile-manual
+
+Building on Windows:
+---------------------
+
+To build the HIDAPI DLL on Windows using Visual Studio, build the .sln file
+in the windows/ directory.
+
+To build the Test GUI on windows using Visual Studio, build the .sln file in
+the testgui/ directory.
+
+To build HIDAPI using MinGW or Cygwin using Autotools, use the instructions
+in the section titled "Building HIDAPI into a shared library on Unix
+Platforms" above.  Note that building the Test GUI with MinGW or Cygwin will
+require the Windows procedure in the Prerequisites section above (ie:
+hidapi-externals.zip).
+
+To build HIDAPI using MinGW using the Manual Makefiles, see the section
+"Building the manual way on Unix platforms" above.
+
+HIDAPI can also be built using the Windows DDK (now also called the Windows
+Driver Kit or WDK). This method was originally required for the HIDAPI build
+but not anymore. However, some users still prefer this method. It is not as
+well supported anymore but should still work. Patches are welcome if it does
+not. To build using the DDK:
+
+   1. Install the Windows Driver Kit (WDK) from Microsoft.
+   2. From the Start menu, in the Windows Driver Kits folder, select Build
+      Environments, then your operating system, then the x86 Free Build
+      Environment (or one that is appropriate for your system).
+   3. From the console, change directory to the windows/ddk_build/ directory,
+      which is part of the HIDAPI distribution.
+   4. Type build.
+   5. You can find the output files (DLL and LIB) in a subdirectory created
+      by the build system which is appropriate for your environment. On
+      Windows XP, this directory is objfre_wxp_x86/i386.
+
+Cross Compiling
+================
+
+This section talks about cross compiling HIDAPI for Linux using autotools.
+This is useful for using HIDAPI on embedded Linux targets.  These
+instructions assume the most raw kind of embedded Linux build, where all
+prerequisites will need to be built first.  This process will of course vary
+based on your embedded Linux build system if you are using one, such as
+OpenEmbedded or Buildroot.
+
+For the purpose of this section, it will be assumed that the following
+environment variables are exported.
+
+	$ export STAGING=$HOME/out
+	$ export HOST=arm-linux
+
+STAGING and HOST can be modified to suit your setup.
+
+Prerequisites
+--------------
+
+Note that the build of libudev is the very basic configuration.
+
+Build Libusb. From the libusb source directory, run:
+	./configure --host=$HOST --prefix=$STAGING
+	make
+	make install
+
+Build libudev. From the libudev source directory, run:
+	./configure --disable-gudev --disable-introspection --disable-hwdb \
+		 --host=$HOST --prefix=$STAGING
+	make
+	make install
+
+Building HIDAPI
+----------------
+
+Build HIDAPI:
+
+	PKG_CONFIG_DIR= \
+	PKG_CONFIG_LIBDIR=$STAGING/lib/pkgconfig:$STAGING/share/pkgconfig \
+	PKG_CONFIG_SYSROOT_DIR=$STAGING \
+	./configure --host=$HOST --prefix=$STAGING
+
+
+Signal 11 Software - 2010-04-11
+                     2010-07-28
+                     2011-09-10
+                     2012-05-01
+                     2012-07-03

vendor/github.com/karalabe/hid/hidapi/hidapi/hidapi.h

@@ -0,0 +1,391 @@
+/*******************************************************
+ HIDAPI - Multi-Platform library for
+ communication with HID devices.
+
+ Alan Ott
+ Signal 11 Software
+
+ 8/22/2009
+
+ Copyright 2009, All Rights Reserved.
+
+ At the discretion of the user of this library,
+ this software may be licensed under the terms of the
+ GNU General Public License v3, a BSD-Style license, or the
+ original HIDAPI license as outlined in the LICENSE.txt,
+ LICENSE-gpl3.txt, LICENSE-bsd.txt, and LICENSE-orig.txt
+ files located at the root of the source distribution.
+ These files may also be found in the public source
+ code repository located at:
+        http://github.com/signal11/hidapi .
+********************************************************/
+
+/** @file
+ * @defgroup API hidapi API
+ */
+
+#ifndef HIDAPI_H__
+#define HIDAPI_H__
+
+#include <wchar.h>
+
+#ifdef _WIN32
+      #define HID_API_EXPORT __declspec(dllexport)
+      #define HID_API_CALL
+#else
+      #define HID_API_EXPORT /**< API export macro */
+      #define HID_API_CALL /**< API call macro */
+#endif
+
+#define HID_API_EXPORT_CALL HID_API_EXPORT HID_API_CALL /**< API export and call macro*/
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+		struct hid_device_;
+		typedef struct hid_device_ hid_device; /**< opaque hidapi structure */
+
+		/** hidapi info structure */
+		struct hid_device_info {
+			/** Platform-specific device path */
+			char *path;
+			/** Device Vendor ID */
+			unsigned short vendor_id;
+			/** Device Product ID */
+			unsigned short product_id;
+			/** Serial Number */
+			wchar_t *serial_number;
+			/** Device Release Number in binary-coded decimal,
+			    also known as Device Version Number */
+			unsigned short release_number;
+			/** Manufacturer String */
+			wchar_t *manufacturer_string;
+			/** Product string */
+			wchar_t *product_string;
+			/** Usage Page for this Device/Interface
+			    (Windows/Mac only). */
+			unsigned short usage_page;
+			/** Usage for this Device/Interface
+			    (Windows/Mac only).*/
+			unsigned short usage;
+			/** The USB interface which this logical device
+			    represents. Valid on both Linux implementations
+			    in all cases, and valid on the Windows implementation
+			    only if the device contains more than one interface. */
+			int interface_number;
+
+			/** Pointer to the next device */
+			struct hid_device_info *next;
+		};
+
+
+		/** @brief Initialize the HIDAPI library.
+
+			This function initializes the HIDAPI library. Calling it is not
+			strictly necessary, as it will be called automatically by
+			hid_enumerate() and any of the hid_open_*() functions if it is
+			needed.  This function should be called at the beginning of
+			execution however, if there is a chance of HIDAPI handles
+			being opened by different threads simultaneously.
+			
+			@ingroup API
+
+			@returns
+				This function returns 0 on success and -1 on error.
+		*/
+		int HID_API_EXPORT HID_API_CALL hid_init(void);
+
+		/** @brief Finalize the HIDAPI library.
+
+			This function frees all of the static data associated with
+			HIDAPI. It should be called at the end of execution to avoid
+			memory leaks.
+
+			@ingroup API
+
+		    @returns
+				This function returns 0 on success and -1 on error.
+		*/
+		int HID_API_EXPORT HID_API_CALL hid_exit(void);
+
+		/** @brief Enumerate the HID Devices.
+
+			This function returns a linked list of all the HID devices
+			attached to the system which match vendor_id and product_id.
+			If @p vendor_id is set to 0 then any vendor matches.
+			If @p product_id is set to 0 then any product matches.
+			If @p vendor_id and @p product_id are both set to 0, then
+			all HID devices will be returned.
+
+			@ingroup API
+			@param vendor_id The Vendor ID (VID) of the types of device
+				to open.
+			@param product_id The Product ID (PID) of the types of
+				device to open.
+
+		    @returns
+		    	This function returns a pointer to a linked list of type
+		    	struct #hid_device, containing information about the HID devices
+		    	attached to the system, or NULL in the case of failure. Free
+		    	this linked list by calling hid_free_enumeration().
+		*/
+		struct hid_device_info HID_API_EXPORT * HID_API_CALL hid_enumerate(unsigned short vendor_id, unsigned short product_id);
+
+		/** @brief Free an enumeration Linked List
+
+		    This function frees a linked list created by hid_enumerate().
+
+			@ingroup API
+		    @param devs Pointer to a list of struct_device returned from
+		    	      hid_enumerate().
+		*/
+		void  HID_API_EXPORT HID_API_CALL hid_free_enumeration(struct hid_device_info *devs);
+
+		/** @brief Open a HID device using a Vendor ID (VID), Product ID
+			(PID) and optionally a serial number.
+
+			If @p serial_number is NULL, the first device with the
+			specified VID and PID is opened.
+
+			@ingroup API
+			@param vendor_id The Vendor ID (VID) of the device to open.
+			@param product_id The Product ID (PID) of the device to open.
+			@param serial_number The Serial Number of the device to open
+				               (Optionally NULL).
+
+			@returns
+				This function returns a pointer to a #hid_device object on
+				success or NULL on failure.
+		*/
+		HID_API_EXPORT hid_device * HID_API_CALL hid_open(unsigned short vendor_id, unsigned short product_id, const wchar_t *serial_number);
+
+		/** @brief Open a HID device by its path name.
+
+			The path name be determined by calling hid_enumerate(), or a
+			platform-specific path name can be used (eg: /dev/hidraw0 on
+			Linux).
+
+			@ingroup API
+		    @param path The path name of the device to open
+
+			@returns
+				This function returns a pointer to a #hid_device object on
+				success or NULL on failure.
+		*/
+		HID_API_EXPORT hid_device * HID_API_CALL hid_open_path(const char *path);
+
+		/** @brief Write an Output report to a HID device.
+
+			The first byte of @p data[] must contain the Report ID. For
+			devices which only support a single report, this must be set
+			to 0x0. The remaining bytes contain the report data. Since
+			the Report ID is mandatory, calls to hid_write() will always
+			contain one more byte than the report contains. For example,
+			if a hid report is 16 bytes long, 17 bytes must be passed to
+			hid_write(), the Report ID (or 0x0, for devices with a
+			single report), followed by the report data (16 bytes). In
+			this example, the length passed in would be 17.
+
+			hid_write() will send the data on the first OUT endpoint, if
+			one exists. If it does not, it will send the data through
+			the Control Endpoint (Endpoint 0).
+
+			@ingroup API
+			@param device A device handle returned from hid_open().
+			@param data The data to send, including the report number as
+				the first byte.
+			@param length The length in bytes of the data to send.
+
+			@returns
+				This function returns the actual number of bytes written and
+				-1 on error.
+		*/
+		int  HID_API_EXPORT HID_API_CALL hid_write(hid_device *device, const unsigned char *data, size_t length);
+
+		/** @brief Read an Input report from a HID device with timeout.
+
+			Input reports are returned
+			to the host through the INTERRUPT IN endpoint. The first byte will
+			contain the Report number if the device uses numbered reports.
+
+			@ingroup API
+			@param device A device handle returned from hid_open().
+			@param data A buffer to put the read data into.
+			@param length The number of bytes to read. For devices with
+				multiple reports, make sure to read an extra byte for
+				the report number.
+			@param milliseconds timeout in milliseconds or -1 for blocking wait.
+
+			@returns
+				This function returns the actual number of bytes read and
+				-1 on error. If no packet was available to be read within
+				the timeout period, this function returns 0.
+		*/
+		int HID_API_EXPORT HID_API_CALL hid_read_timeout(hid_device *dev, unsigned char *data, size_t length, int milliseconds);
+
+		/** @brief Read an Input report from a HID device.
+
+			Input reports are returned
+		    to the host through the INTERRUPT IN endpoint. The first byte will
+			contain the Report number if the device uses numbered reports.
+
+			@ingroup API
+			@param device A device handle returned from hid_open().
+			@param data A buffer to put the read data into.
+			@param length The number of bytes to read. For devices with
+				multiple reports, make sure to read an extra byte for
+				the report number.
+
+			@returns
+				This function returns the actual number of bytes read and
+				-1 on error. If no packet was available to be read and
+				the handle is in non-blocking mode, this function returns 0.
+		*/
+		int  HID_API_EXPORT HID_API_CALL hid_read(hid_device *device, unsigned char *data, size_t length);
+
+		/** @brief Set the device handle to be non-blocking.
+
+			In non-blocking mode calls to hid_read() will return
+			immediately with a value of 0 if there is no data to be
+			read. In blocking mode, hid_read() will wait (block) until
+			there is data to read before returning.
+
+			Nonblocking can be turned on and off at any time.
+
+			@ingroup API
+			@param device A device handle returned from hid_open().
+			@param nonblock enable or not the nonblocking reads
+			 - 1 to enable nonblocking
+			 - 0 to disable nonblocking.
+
+			@returns
+				This function returns 0 on success and -1 on error.
+		*/
+		int  HID_API_EXPORT HID_API_CALL hid_set_nonblocking(hid_device *device, int nonblock);
+
+		/** @brief Send a Feature report to the device.
+
+			Feature reports are sent over the Control endpoint as a
+			Set_Report transfer.  The first byte of @p data[] must
+			contain the Report ID. For devices which only support a
+			single report, this must be set to 0x0. The remaining bytes
+			contain the report data. Since the Report ID is mandatory,
+			calls to hid_send_feature_report() will always contain one
+			more byte than the report contains. For example, if a hid
+			report is 16 bytes long, 17 bytes must be passed to
+			hid_send_feature_report(): the Report ID (or 0x0, for
+			devices which do not use numbered reports), followed by the
+			report data (16 bytes). In this example, the length passed
+			in would be 17.
+
+			@ingroup API
+			@param device A device handle returned from hid_open().
+			@param data The data to send, including the report number as
+				the first byte.
+			@param length The length in bytes of the data to send, including
+				the report number.
+
+			@returns
+				This function returns the actual number of bytes written and
+				-1 on error.
+		*/
+		int HID_API_EXPORT HID_API_CALL hid_send_feature_report(hid_device *device, const unsigned char *data, size_t length);
+
+		/** @brief Get a feature report from a HID device.
+
+			Set the first byte of @p data[] to the Report ID of the
+			report to be read.  Make sure to allow space for this
+			extra byte in @p data[]. Upon return, the first byte will
+			still contain the Report ID, and the report data will
+			start in data[1].
+
+			@ingroup API
+			@param device A device handle returned from hid_open().
+			@param data A buffer to put the read data into, including
+				the Report ID. Set the first byte of @p data[] to the
+				Report ID of the report to be read, or set it to zero
+				if your device does not use numbered reports.
+			@param length The number of bytes to read, including an
+				extra byte for the report ID. The buffer can be longer
+				than the actual report.
+
+			@returns
+				This function returns the number of bytes read plus
+				one for the report ID (which is still in the first
+				byte), or -1 on error.
+		*/
+		int HID_API_EXPORT HID_API_CALL hid_get_feature_report(hid_device *device, unsigned char *data, size_t length);
+
+		/** @brief Close a HID device.
+
+			@ingroup API
+			@param device A device handle returned from hid_open().
+		*/
+		void HID_API_EXPORT HID_API_CALL hid_close(hid_device *device);
+
+		/** @brief Get The Manufacturer String from a HID device.
+
+			@ingroup API
+			@param device A device handle returned from hid_open().
+			@param string A wide string buffer to put the data into.
+			@param maxlen The length of the buffer in multiples of wchar_t.
+
+			@returns
+				This function returns 0 on success and -1 on error.
+		*/
+		int HID_API_EXPORT_CALL hid_get_manufacturer_string(hid_device *device, wchar_t *string, size_t maxlen);
+
+		/** @brief Get The Product String from a HID device.
+
+			@ingroup API
+			@param device A device handle returned from hid_open().
+			@param string A wide string buffer to put the data into.
+			@param maxlen The length of the buffer in multiples of wchar_t.
+
+			@returns
+				This function returns 0 on success and -1 on error.
+		*/
+		int HID_API_EXPORT_CALL hid_get_product_string(hid_device *device, wchar_t *string, size_t maxlen);
+
+		/** @brief Get The Serial Number String from a HID device.
+
+			@ingroup API
+			@param device A device handle returned from hid_open().
+			@param string A wide string buffer to put the data into.
+			@param maxlen The length of the buffer in multiples of wchar_t.
+
+			@returns
+				This function returns 0 on success and -1 on error.
+		*/
+		int HID_API_EXPORT_CALL hid_get_serial_number_string(hid_device *device, wchar_t *string, size_t maxlen);
+
+		/** @brief Get a string from a HID device, based on its string index.
+
+			@ingroup API
+			@param device A device handle returned from hid_open().
+			@param string_index The index of the string to get.
+			@param string A wide string buffer to put the data into.
+			@param maxlen The length of the buffer in multiples of wchar_t.
+
+			@returns
+				This function returns 0 on success and -1 on error.
+		*/
+		int HID_API_EXPORT_CALL hid_get_indexed_string(hid_device *device, int string_index, wchar_t *string, size_t maxlen);
+
+		/** @brief Get a string describing the last error which occurred.
+
+			@ingroup API
+			@param device A device handle returned from hid_open().
+
+			@returns
+				This function returns a string containing the last error
+				which occurred or NULL if none has occurred.
+		*/
+		HID_API_EXPORT const wchar_t* HID_API_CALL hid_error(hid_device *device);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif
+

vendor/github.com/karalabe/hid/hidapi/windows/hid.c

@@ -0,0 +1,944 @@
+/*******************************************************
+ HIDAPI - Multi-Platform library for
+ communication with HID devices.
+
+ Alan Ott
+ Signal 11 Software
+
+ 8/22/2009
+
+ Copyright 2009, All Rights Reserved.
+ 
+ At the discretion of the user of this library,
+ this software may be licensed under the terms of the
+ GNU General Public License v3, a BSD-Style license, or the
+ original HIDAPI license as outlined in the LICENSE.txt,
+ LICENSE-gpl3.txt, LICENSE-bsd.txt, and LICENSE-orig.txt
+ files located at the root of the source distribution.
+ These files may also be found in the public source
+ code repository located at:
+        http://github.com/signal11/hidapi .
+********************************************************/
+
+#include <windows.h>
+
+#ifndef _NTDEF_
+typedef LONG NTSTATUS;
+#endif
+
+#ifdef __MINGW32__
+#include <ntdef.h>
+#include <winbase.h>
+#endif
+
+#ifdef __CYGWIN__
+#include <ntdef.h>
+#define _wcsdup wcsdup
+#endif
+
+/* The maximum number of characters that can be passed into the
+   HidD_Get*String() functions without it failing.*/
+#define MAX_STRING_WCHARS 0xFFF
+
+/*#define HIDAPI_USE_DDK*/
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+	#include <setupapi.h>
+	#include <winioctl.h>
+	#ifdef HIDAPI_USE_DDK
+		#include <hidsdi.h>
+	#endif
+
+	/* Copied from inc/ddk/hidclass.h, part of the Windows DDK. */
+	#define HID_OUT_CTL_CODE(id)  \
+		CTL_CODE(FILE_DEVICE_KEYBOARD, (id), METHOD_OUT_DIRECT, FILE_ANY_ACCESS)
+	#define IOCTL_HID_GET_FEATURE                   HID_OUT_CTL_CODE(100)
+
+#ifdef __cplusplus
+} /* extern "C" */
+#endif
+
+#include <stdio.h>
+#include <stdlib.h>
+
+
+#include "hidapi.h"
+
+#undef MIN
+#define MIN(x,y) ((x) < (y)? (x): (y))
+
+#ifdef _MSC_VER
+	/* Thanks Microsoft, but I know how to use strncpy(). */
+	#pragma warning(disable:4996)
+#endif
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#ifndef HIDAPI_USE_DDK
+	/* Since we're not building with the DDK, and the HID header
+	   files aren't part of the SDK, we have to define all this
+	   stuff here. In lookup_functions(), the function pointers
+	   defined below are set. */
+	typedef struct _HIDD_ATTRIBUTES{
+		ULONG Size;
+		USHORT VendorID;
+		USHORT ProductID;
+		USHORT VersionNumber;
+	} HIDD_ATTRIBUTES, *PHIDD_ATTRIBUTES;
+
+	typedef USHORT USAGE;
+	typedef struct _HIDP_CAPS {
+		USAGE Usage;
+		USAGE UsagePage;
+		USHORT InputReportByteLength;
+		USHORT OutputReportByteLength;
+		USHORT FeatureReportByteLength;
+		USHORT Reserved[17];
+		USHORT fields_not_used_by_hidapi[10];
+	} HIDP_CAPS, *PHIDP_CAPS;
+	typedef void* PHIDP_PREPARSED_DATA;
+	#define HIDP_STATUS_SUCCESS 0x110000
+
+	typedef BOOLEAN (__stdcall *HidD_GetAttributes_)(HANDLE device, PHIDD_ATTRIBUTES attrib);
+	typedef BOOLEAN (__stdcall *HidD_GetSerialNumberString_)(HANDLE device, PVOID buffer, ULONG buffer_len);
+	typedef BOOLEAN (__stdcall *HidD_GetManufacturerString_)(HANDLE handle, PVOID buffer, ULONG buffer_len);
+	typedef BOOLEAN (__stdcall *HidD_GetProductString_)(HANDLE handle, PVOID buffer, ULONG buffer_len);
+	typedef BOOLEAN (__stdcall *HidD_SetFeature_)(HANDLE handle, PVOID data, ULONG length);
+	typedef BOOLEAN (__stdcall *HidD_GetFeature_)(HANDLE handle, PVOID data, ULONG length);
+	typedef BOOLEAN (__stdcall *HidD_GetIndexedString_)(HANDLE handle, ULONG string_index, PVOID buffer, ULONG buffer_len);
+	typedef BOOLEAN (__stdcall *HidD_GetPreparsedData_)(HANDLE handle, PHIDP_PREPARSED_DATA *preparsed_data);
+	typedef BOOLEAN (__stdcall *HidD_FreePreparsedData_)(PHIDP_PREPARSED_DATA preparsed_data);
+	typedef NTSTATUS (__stdcall *HidP_GetCaps_)(PHIDP_PREPARSED_DATA preparsed_data, HIDP_CAPS *caps);
+	typedef BOOLEAN (__stdcall *HidD_SetNumInputBuffers_)(HANDLE handle, ULONG number_buffers);
+
+	static HidD_GetAttributes_ HidD_GetAttributes;
+	static HidD_GetSerialNumberString_ HidD_GetSerialNumberString;
+	static HidD_GetManufacturerString_ HidD_GetManufacturerString;
+	static HidD_GetProductString_ HidD_GetProductString;
+	static HidD_SetFeature_ HidD_SetFeature;
+	static HidD_GetFeature_ HidD_GetFeature;
+	static HidD_GetIndexedString_ HidD_GetIndexedString;
+	static HidD_GetPreparsedData_ HidD_GetPreparsedData;
+	static HidD_FreePreparsedData_ HidD_FreePreparsedData;
+	static HidP_GetCaps_ HidP_GetCaps;
+	static HidD_SetNumInputBuffers_ HidD_SetNumInputBuffers;
+
+	static HMODULE lib_handle = NULL;
+	static BOOLEAN initialized = FALSE;
+#endif /* HIDAPI_USE_DDK */
+
+struct hid_device_ {
+		HANDLE device_handle;
+		BOOL blocking;
+		USHORT output_report_length;
+		size_t input_report_length;
+		void *last_error_str;
+		DWORD last_error_num;
+		BOOL read_pending;
+		char *read_buf;
+		OVERLAPPED ol;
+};
+
+static hid_device *new_hid_device()
+{
+	hid_device *dev = (hid_device*) calloc(1, sizeof(hid_device));
+	dev->device_handle = INVALID_HANDLE_VALUE;
+	dev->blocking = TRUE;
+	dev->output_report_length = 0;
+	dev->input_report_length = 0;
+	dev->last_error_str = NULL;
+	dev->last_error_num = 0;
+	dev->read_pending = FALSE;
+	dev->read_buf = NULL;
+	memset(&dev->ol, 0, sizeof(dev->ol));
+	dev->ol.hEvent = CreateEvent(NULL, FALSE, FALSE /*initial state f=nonsignaled*/, NULL);
+
+	return dev;
+}
+
+static void free_hid_device(hid_device *dev)
+{
+	CloseHandle(dev->ol.hEvent);
+	CloseHandle(dev->device_handle);
+	LocalFree(dev->last_error_str);
+	free(dev->read_buf);
+	free(dev);
+}
+
+static void register_error(hid_device *device, const char *op)
+{
+	WCHAR *ptr, *msg;
+
+	FormatMessageW(FORMAT_MESSAGE_ALLOCATE_BUFFER |
+		FORMAT_MESSAGE_FROM_SYSTEM |
+		FORMAT_MESSAGE_IGNORE_INSERTS,
+		NULL,
+		GetLastError(),
+		MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT),
+		(LPVOID)&msg, 0/*sz*/,
+		NULL);
+	
+	/* Get rid of the CR and LF that FormatMessage() sticks at the
+	   end of the message. Thanks Microsoft! */
+	ptr = msg;
+	while (*ptr) {
+		if (*ptr == '\r') {
+			*ptr = 0x0000;
+			break;
+		}
+		ptr++;
+	}
+
+	/* Store the message off in the Device entry so that
+	   the hid_error() function can pick it up. */
+	LocalFree(device->last_error_str);
+	device->last_error_str = msg;
+}
+
+#ifndef HIDAPI_USE_DDK
+static int lookup_functions()
+{
+	lib_handle = LoadLibraryA("hid.dll");
+	if (lib_handle) {
+#define RESOLVE(x) x = (x##_)GetProcAddress(lib_handle, #x); if (!x) return -1;
+		RESOLVE(HidD_GetAttributes);
+		RESOLVE(HidD_GetSerialNumberString);
+		RESOLVE(HidD_GetManufacturerString);
+		RESOLVE(HidD_GetProductString);
+		RESOLVE(HidD_SetFeature);
+		RESOLVE(HidD_GetFeature);
+		RESOLVE(HidD_GetIndexedString);
+		RESOLVE(HidD_GetPreparsedData);
+		RESOLVE(HidD_FreePreparsedData);
+		RESOLVE(HidP_GetCaps);
+		RESOLVE(HidD_SetNumInputBuffers);
+#undef RESOLVE
+	}
+	else
+		return -1;
+
+	return 0;
+}
+#endif
+
+static HANDLE open_device(const char *path, BOOL enumerate)
+{
+	HANDLE handle;
+	DWORD desired_access = (enumerate)? 0: (GENERIC_WRITE | GENERIC_READ);
+	DWORD share_mode = FILE_SHARE_READ|FILE_SHARE_WRITE;
+
+	handle = CreateFileA(path,
+		desired_access,
+		share_mode,
+		NULL,
+		OPEN_EXISTING,
+		FILE_FLAG_OVERLAPPED,/*FILE_ATTRIBUTE_NORMAL,*/
+		0);
+
+	return handle;
+}
+
+int HID_API_EXPORT hid_init(void)
+{
+#ifndef HIDAPI_USE_DDK
+	if (!initialized) {
+		if (lookup_functions() < 0) {
+			hid_exit();
+			return -1;
+		}
+		initialized = TRUE;
+	}
+#endif
+	return 0;
+}
+
+int HID_API_EXPORT hid_exit(void)
+{
+#ifndef HIDAPI_USE_DDK
+	if (lib_handle)
+		FreeLibrary(lib_handle);
+	lib_handle = NULL;
+	initialized = FALSE;
+#endif
+	return 0;
+}
+
+struct hid_device_info HID_API_EXPORT * HID_API_CALL hid_enumerate(unsigned short vendor_id, unsigned short product_id)
+{
+	BOOL res;
+	struct hid_device_info *root = NULL; /* return object */
+	struct hid_device_info *cur_dev = NULL;
+
+	/* Windows objects for interacting with the driver. */
+	GUID InterfaceClassGuid = {0x4d1e55b2, 0xf16f, 0x11cf, {0x88, 0xcb, 0x00, 0x11, 0x11, 0x00, 0x00, 0x30} };
+	SP_DEVINFO_DATA devinfo_data;
+	SP_DEVICE_INTERFACE_DATA device_interface_data;
+	SP_DEVICE_INTERFACE_DETAIL_DATA_A *device_interface_detail_data = NULL;
+	HDEVINFO device_info_set = INVALID_HANDLE_VALUE;
+	int device_index = 0;
+	int i;
+
+	if (hid_init() < 0)
+		return NULL;
+
+	/* Initialize the Windows objects. */
+	memset(&devinfo_data, 0x0, sizeof(devinfo_data));
+	devinfo_data.cbSize = sizeof(SP_DEVINFO_DATA);
+	device_interface_data.cbSize = sizeof(SP_DEVICE_INTERFACE_DATA);
+
+	/* Get information for all the devices belonging to the HID class. */
+	device_info_set = SetupDiGetClassDevsA(&InterfaceClassGuid, NULL, NULL, DIGCF_PRESENT | DIGCF_DEVICEINTERFACE);
+	
+	/* Iterate over each device in the HID class, looking for the right one. */
+	
+	for (;;) {
+		HANDLE write_handle = INVALID_HANDLE_VALUE;
+		DWORD required_size = 0;
+		HIDD_ATTRIBUTES attrib;
+
+		res = SetupDiEnumDeviceInterfaces(device_info_set,
+			NULL,
+			&InterfaceClassGuid,
+			device_index,
+			&device_interface_data);
+		
+		if (!res) {
+			/* A return of FALSE from this function means that
+			   there are no more devices. */
+			break;
+		}
+
+		/* Call with 0-sized detail size, and let the function
+		   tell us how long the detail struct needs to be. The
+		   size is put in &required_size. */
+		res = SetupDiGetDeviceInterfaceDetailA(device_info_set,
+			&device_interface_data,
+			NULL,
+			0,
+			&required_size,
+			NULL);
+
+		/* Allocate a long enough structure for device_interface_detail_data. */
+		device_interface_detail_data = (SP_DEVICE_INTERFACE_DETAIL_DATA_A*) malloc(required_size);
+		device_interface_detail_data->cbSize = sizeof(SP_DEVICE_INTERFACE_DETAIL_DATA_A);
+
+		/* Get the detailed data for this device. The detail data gives us
+		   the device path for this device, which is then passed into
+		   CreateFile() to get a handle to the device. */
+		res = SetupDiGetDeviceInterfaceDetailA(device_info_set,
+			&device_interface_data,
+			device_interface_detail_data,
+			required_size,
+			NULL,
+			NULL);
+
+		if (!res) {
+			/* register_error(dev, "Unable to call SetupDiGetDeviceInterfaceDetail");
+			   Continue to the next device. */
+			goto cont;
+		}
+
+		/* Make sure this device is of Setup Class "HIDClass" and has a
+		   driver bound to it. */
+		for (i = 0; ; i++) {
+			char driver_name[256];
+
+			/* Populate devinfo_data. This function will return failure
+			   when there are no more interfaces left. */
+			res = SetupDiEnumDeviceInfo(device_info_set, i, &devinfo_data);
+			if (!res)
+				goto cont;
+
+			res = SetupDiGetDeviceRegistryPropertyA(device_info_set, &devinfo_data,
+			               SPDRP_CLASS, NULL, (PBYTE)driver_name, sizeof(driver_name), NULL);
+			if (!res)
+				goto cont;
+
+			if (strcmp(driver_name, "HIDClass") == 0) {
+				/* See if there's a driver bound. */
+				res = SetupDiGetDeviceRegistryPropertyA(device_info_set, &devinfo_data,
+				           SPDRP_DRIVER, NULL, (PBYTE)driver_name, sizeof(driver_name), NULL);
+				if (res)
+					break;
+			}
+		}
+
+		//wprintf(L"HandleName: %s\n", device_interface_detail_data->DevicePath);
+
+		/* Open a handle to the device */
+		write_handle = open_device(device_interface_detail_data->DevicePath, TRUE);
+
+		/* Check validity of write_handle. */
+		if (write_handle == INVALID_HANDLE_VALUE) {
+			/* Unable to open the device. */
+			//register_error(dev, "CreateFile");
+			goto cont_close;
+		}		
+
+
+		/* Get the Vendor ID and Product ID for this device. */
+		attrib.Size = sizeof(HIDD_ATTRIBUTES);
+		HidD_GetAttributes(write_handle, &attrib);
+		//wprintf(L"Product/Vendor: %x %x\n", attrib.ProductID, attrib.VendorID);
+
+		/* Check the VID/PID to see if we should add this
+		   device to the enumeration list. */
+		if ((vendor_id == 0x0 || attrib.VendorID == vendor_id) &&
+		    (product_id == 0x0 || attrib.ProductID == product_id)) {
+
+			#define WSTR_LEN 512
+			const char *str;
+			struct hid_device_info *tmp;
+			PHIDP_PREPARSED_DATA pp_data = NULL;
+			HIDP_CAPS caps;
+			BOOLEAN res;
+			NTSTATUS nt_res;
+			wchar_t wstr[WSTR_LEN]; /* TODO: Determine Size */
+			size_t len;
+
+			/* VID/PID match. Create the record. */
+			tmp = (struct hid_device_info*) calloc(1, sizeof(struct hid_device_info));
+			if (cur_dev) {
+				cur_dev->next = tmp;
+			}
+			else {
+				root = tmp;
+			}
+			cur_dev = tmp;
+
+			/* Get the Usage Page and Usage for this device. */
+			res = HidD_GetPreparsedData(write_handle, &pp_data);
+			if (res) {
+				nt_res = HidP_GetCaps(pp_data, &caps);
+				if (nt_res == HIDP_STATUS_SUCCESS) {
+					cur_dev->usage_page = caps.UsagePage;
+					cur_dev->usage = caps.Usage;
+				}
+
+				HidD_FreePreparsedData(pp_data);
+			}
+			
+			/* Fill out the record */
+			cur_dev->next = NULL;
+			str = device_interface_detail_data->DevicePath;
+			if (str) {
+				len = strlen(str);
+				cur_dev->path = (char*) calloc(len+1, sizeof(char));
+				strncpy(cur_dev->path, str, len+1);
+				cur_dev->path[len] = '\0';
+			}
+			else
+				cur_dev->path = NULL;
+
+			/* Serial Number */
+			res = HidD_GetSerialNumberString(write_handle, wstr, sizeof(wstr));
+			wstr[WSTR_LEN-1] = 0x0000;
+			if (res) {
+				cur_dev->serial_number = _wcsdup(wstr);
+			}
+
+			/* Manufacturer String */
+			res = HidD_GetManufacturerString(write_handle, wstr, sizeof(wstr));
+			wstr[WSTR_LEN-1] = 0x0000;
+			if (res) {
+				cur_dev->manufacturer_string = _wcsdup(wstr);
+			}
+
+			/* Product String */
+			res = HidD_GetProductString(write_handle, wstr, sizeof(wstr));
+			wstr[WSTR_LEN-1] = 0x0000;
+			if (res) {
+				cur_dev->product_string = _wcsdup(wstr);
+			}
+
+			/* VID/PID */
+			cur_dev->vendor_id = attrib.VendorID;
+			cur_dev->product_id = attrib.ProductID;
+
+			/* Release Number */
+			cur_dev->release_number = attrib.VersionNumber;
+
+			/* Interface Number. It can sometimes be parsed out of the path
+			   on Windows if a device has multiple interfaces. See
+			   http://msdn.microsoft.com/en-us/windows/hardware/gg487473 or
+			   search for "Hardware IDs for HID Devices" at MSDN. If it's not
+			   in the path, it's set to -1. */
+			cur_dev->interface_number = -1;
+			if (cur_dev->path) {
+				char *interface_component = strstr(cur_dev->path, "&mi_");
+				if (interface_component) {
+					char *hex_str = interface_component + 4;
+					char *endptr = NULL;
+					cur_dev->interface_number = strtol(hex_str, &endptr, 16);
+					if (endptr == hex_str) {
+						/* The parsing failed. Set interface_number to -1. */
+						cur_dev->interface_number = -1;
+					}
+				}
+			}
+		}
+
+cont_close:
+		CloseHandle(write_handle);
+cont:
+		/* We no longer need the detail data. It can be freed */
+		free(device_interface_detail_data);
+
+		device_index++;
+
+	}
+
+	/* Close the device information handle. */
+	SetupDiDestroyDeviceInfoList(device_info_set);
+
+	return root;
+
+}
+
+void  HID_API_EXPORT HID_API_CALL hid_free_enumeration(struct hid_device_info *devs)
+{
+	/* TODO: Merge this with the Linux version. This function is platform-independent. */
+	struct hid_device_info *d = devs;
+	while (d) {
+		struct hid_device_info *next = d->next;
+		free(d->path);
+		free(d->serial_number);
+		free(d->manufacturer_string);
+		free(d->product_string);
+		free(d);
+		d = next;
+	}
+}
+
+
+HID_API_EXPORT hid_device * HID_API_CALL hid_open(unsigned short vendor_id, unsigned short product_id, const wchar_t *serial_number)
+{
+	/* TODO: Merge this functions with the Linux version. This function should be platform independent. */
+	struct hid_device_info *devs, *cur_dev;
+	const char *path_to_open = NULL;
+	hid_device *handle = NULL;
+	
+	devs = hid_enumerate(vendor_id, product_id);
+	cur_dev = devs;
+	while (cur_dev) {
+		if (cur_dev->vendor_id == vendor_id &&
+		    cur_dev->product_id == product_id) {
+			if (serial_number) {
+				if (wcscmp(serial_number, cur_dev->serial_number) == 0) {
+					path_to_open = cur_dev->path;
+					break;
+				}
+			}
+			else {
+				path_to_open = cur_dev->path;
+				break;
+			}
+		}
+		cur_dev = cur_dev->next;
+	}
+
+	if (path_to_open) {
+		/* Open the device */
+		handle = hid_open_path(path_to_open);
+	}
+
+	hid_free_enumeration(devs);
+	
+	return handle;
+}
+
+HID_API_EXPORT hid_device * HID_API_CALL hid_open_path(const char *path)
+{
+	hid_device *dev;
+	HIDP_CAPS caps;
+	PHIDP_PREPARSED_DATA pp_data = NULL;
+	BOOLEAN res;
+	NTSTATUS nt_res;
+
+	if (hid_init() < 0) {
+		return NULL;
+	}
+
+	dev = new_hid_device();
+
+	/* Open a handle to the device */
+	dev->device_handle = open_device(path, FALSE);
+
+	/* Check validity of write_handle. */
+	if (dev->device_handle == INVALID_HANDLE_VALUE) {
+		/* Unable to open the device. */
+		register_error(dev, "CreateFile");
+		goto err;
+	}
+
+	/* Set the Input Report buffer size to 64 reports. */
+	res = HidD_SetNumInputBuffers(dev->device_handle, 64);
+	if (!res) {
+		register_error(dev, "HidD_SetNumInputBuffers");
+		goto err;
+	}
+
+	/* Get the Input Report length for the device. */
+	res = HidD_GetPreparsedData(dev->device_handle, &pp_data);
+	if (!res) {
+		register_error(dev, "HidD_GetPreparsedData");
+		goto err;
+	}
+	nt_res = HidP_GetCaps(pp_data, &caps);
+	if (nt_res != HIDP_STATUS_SUCCESS) {
+		register_error(dev, "HidP_GetCaps");	
+		goto err_pp_data;
+	}
+	dev->output_report_length = caps.OutputReportByteLength;
+	dev->input_report_length = caps.InputReportByteLength;
+	HidD_FreePreparsedData(pp_data);
+
+	dev->read_buf = (char*) malloc(dev->input_report_length);
+
+	return dev;
+
+err_pp_data:
+		HidD_FreePreparsedData(pp_data);
+err:	
+		free_hid_device(dev);
+		return NULL;
+}
+
+int HID_API_EXPORT HID_API_CALL hid_write(hid_device *dev, const unsigned char *data, size_t length)
+{
+	DWORD bytes_written;
+	BOOL res;
+
+	OVERLAPPED ol;
+	unsigned char *buf;
+	memset(&ol, 0, sizeof(ol));
+
+	/* Make sure the right number of bytes are passed to WriteFile. Windows
+	   expects the number of bytes which are in the _longest_ report (plus
+	   one for the report number) bytes even if the data is a report
+	   which is shorter than that. Windows gives us this value in
+	   caps.OutputReportByteLength. If a user passes in fewer bytes than this,
+	   create a temporary buffer which is the proper size. */
+	if (length >= dev->output_report_length) {
+		/* The user passed the right number of bytes. Use the buffer as-is. */
+		buf = (unsigned char *) data;
+	} else {
+		/* Create a temporary buffer and copy the user's data
+		   into it, padding the rest with zeros. */
+		buf = (unsigned char *) malloc(dev->output_report_length);
+		memcpy(buf, data, length);
+		memset(buf + length, 0, dev->output_report_length - length);
+		length = dev->output_report_length;
+	}
+
+	res = WriteFile(dev->device_handle, buf, length, NULL, &ol);
+	
+	if (!res) {
+		if (GetLastError() != ERROR_IO_PENDING) {
+			/* WriteFile() failed. Return error. */
+			register_error(dev, "WriteFile");
+			bytes_written = -1;
+			goto end_of_function;
+		}
+	}
+
+	/* Wait here until the write is done. This makes
+	   hid_write() synchronous. */
+	res = GetOverlappedResult(dev->device_handle, &ol, &bytes_written, TRUE/*wait*/);
+	if (!res) {
+		/* The Write operation failed. */
+		register_error(dev, "WriteFile");
+		bytes_written = -1;
+		goto end_of_function;
+	}
+
+end_of_function:
+	if (buf != data)
+		free(buf);
+
+	return bytes_written;
+}
+
+
+int HID_API_EXPORT HID_API_CALL hid_read_timeout(hid_device *dev, unsigned char *data, size_t length, int milliseconds)
+{
+	DWORD bytes_read = 0;
+	size_t copy_len = 0;
+	BOOL res;
+
+	/* Copy the handle for convenience. */
+	HANDLE ev = dev->ol.hEvent;
+
+	if (!dev->read_pending) {
+		/* Start an Overlapped I/O read. */
+		dev->read_pending = TRUE;
+		memset(dev->read_buf, 0, dev->input_report_length);
+		ResetEvent(ev);
+		res = ReadFile(dev->device_handle, dev->read_buf, dev->input_report_length, &bytes_read, &dev->ol);
+		
+		if (!res) {
+			if (GetLastError() != ERROR_IO_PENDING) {
+				/* ReadFile() has failed.
+				   Clean up and return error. */
+				CancelIo(dev->device_handle);
+				dev->read_pending = FALSE;
+				goto end_of_function;
+			}
+		}
+	}
+
+	if (milliseconds >= 0) {
+		/* See if there is any data yet. */
+		res = WaitForSingleObject(ev, milliseconds);
+		if (res != WAIT_OBJECT_0) {
+			/* There was no data this time. Return zero bytes available,
+			   but leave the Overlapped I/O running. */
+			return 0;
+		}
+	}
+
+	/* Either WaitForSingleObject() told us that ReadFile has completed, or
+	   we are in non-blocking mode. Get the number of bytes read. The actual
+	   data has been copied to the data[] array which was passed to ReadFile(). */
+	res = GetOverlappedResult(dev->device_handle, &dev->ol, &bytes_read, TRUE/*wait*/);
+	
+	/* Set pending back to false, even if GetOverlappedResult() returned error. */
+	dev->read_pending = FALSE;
+
+	if (res && bytes_read > 0) {
+		if (dev->read_buf[0] == 0x0) {
+			/* If report numbers aren't being used, but Windows sticks a report
+			   number (0x0) on the beginning of the report anyway. To make this
+			   work like the other platforms, and to make it work more like the
+			   HID spec, we'll skip over this byte. */
+			bytes_read--;
+			copy_len = length > bytes_read ? bytes_read : length;
+			memcpy(data, dev->read_buf+1, copy_len);
+		}
+		else {
+			/* Copy the whole buffer, report number and all. */
+			copy_len = length > bytes_read ? bytes_read : length;
+			memcpy(data, dev->read_buf, copy_len);
+		}
+	}
+	
+end_of_function:
+	if (!res) {
+		register_error(dev, "GetOverlappedResult");
+		return -1;
+	}
+	
+	return copy_len;
+}
+
+int HID_API_EXPORT HID_API_CALL hid_read(hid_device *dev, unsigned char *data, size_t length)
+{
+	return hid_read_timeout(dev, data, length, (dev->blocking)? -1: 0);
+}
+
+int HID_API_EXPORT HID_API_CALL hid_set_nonblocking(hid_device *dev, int nonblock)
+{
+	dev->blocking = !nonblock;
+	return 0; /* Success */
+}
+
+int HID_API_EXPORT HID_API_CALL hid_send_feature_report(hid_device *dev, const unsigned char *data, size_t length)
+{
+	BOOL res = HidD_SetFeature(dev->device_handle, (PVOID)data, length);
+	if (!res) {
+		register_error(dev, "HidD_SetFeature");
+		return -1;
+	}
+
+	return length;
+}
+
+
+int HID_API_EXPORT HID_API_CALL hid_get_feature_report(hid_device *dev, unsigned char *data, size_t length)
+{
+	BOOL res;
+#if 0
+	res = HidD_GetFeature(dev->device_handle, data, length);
+	if (!res) {
+		register_error(dev, "HidD_GetFeature");
+		return -1;
+	}
+	return 0; /* HidD_GetFeature() doesn't give us an actual length, unfortunately */
+#else
+	DWORD bytes_returned;
+
+	OVERLAPPED ol;
+	memset(&ol, 0, sizeof(ol));
+
+	res = DeviceIoControl(dev->device_handle,
+		IOCTL_HID_GET_FEATURE,
+		data, length,
+		data, length,
+		&bytes_returned, &ol);
+
+	if (!res) {
+		if (GetLastError() != ERROR_IO_PENDING) {
+			/* DeviceIoControl() failed. Return error. */
+			register_error(dev, "Send Feature Report DeviceIoControl");
+			return -1;
+		}
+	}
+
+	/* Wait here until the write is done. This makes
+	   hid_get_feature_report() synchronous. */
+	res = GetOverlappedResult(dev->device_handle, &ol, &bytes_returned, TRUE/*wait*/);
+	if (!res) {
+		/* The operation failed. */
+		register_error(dev, "Send Feature Report GetOverLappedResult");
+		return -1;
+	}
+
+	/* bytes_returned does not include the first byte which contains the
+	   report ID. The data buffer actually contains one more byte than
+	   bytes_returned. */
+	bytes_returned++;
+
+	return bytes_returned;
+#endif
+}
+
+void HID_API_EXPORT HID_API_CALL hid_close(hid_device *dev)
+{
+	if (!dev)
+		return;
+	CancelIo(dev->device_handle);
+	free_hid_device(dev);
+}
+
+int HID_API_EXPORT_CALL HID_API_CALL hid_get_manufacturer_string(hid_device *dev, wchar_t *string, size_t maxlen)
+{
+	BOOL res;
+
+	res = HidD_GetManufacturerString(dev->device_handle, string, sizeof(wchar_t) * MIN(maxlen, MAX_STRING_WCHARS));
+	if (!res) {
+		register_error(dev, "HidD_GetManufacturerString");
+		return -1;
+	}
+
+	return 0;
+}
+
+int HID_API_EXPORT_CALL HID_API_CALL hid_get_product_string(hid_device *dev, wchar_t *string, size_t maxlen)
+{
+	BOOL res;
+
+	res = HidD_GetProductString(dev->device_handle, string, sizeof(wchar_t) * MIN(maxlen, MAX_STRING_WCHARS));
+	if (!res) {
+		register_error(dev, "HidD_GetProductString");
+		return -1;
+	}
+
+	return 0;
+}
+
+int HID_API_EXPORT_CALL HID_API_CALL hid_get_serial_number_string(hid_device *dev, wchar_t *string, size_t maxlen)
+{
+	BOOL res;
+
+	res = HidD_GetSerialNumberString(dev->device_handle, string, sizeof(wchar_t) * MIN(maxlen, MAX_STRING_WCHARS));
+	if (!res) {
+		register_error(dev, "HidD_GetSerialNumberString");
+		return -1;
+	}
+
+	return 0;
+}
+
+int HID_API_EXPORT_CALL HID_API_CALL hid_get_indexed_string(hid_device *dev, int string_index, wchar_t *string, size_t maxlen)
+{
+	BOOL res;
+
+	res = HidD_GetIndexedString(dev->device_handle, string_index, string, sizeof(wchar_t) * MIN(maxlen, MAX_STRING_WCHARS));
+	if (!res) {
+		register_error(dev, "HidD_GetIndexedString");
+		return -1;
+	}
+
+	return 0;
+}
+
+
+HID_API_EXPORT const wchar_t * HID_API_CALL  hid_error(hid_device *dev)
+{
+	return (wchar_t*)dev->last_error_str;
+}
+
+
+/*#define PICPGM*/
+/*#define S11*/
+#define P32
+#ifdef S11 
+  unsigned short VendorID = 0xa0a0;
+	unsigned short ProductID = 0x0001;
+#endif
+
+#ifdef P32
+  unsigned short VendorID = 0x04d8;
+	unsigned short ProductID = 0x3f;
+#endif
+
+
+#ifdef PICPGM
+  unsigned short VendorID = 0x04d8;
+  unsigned short ProductID = 0x0033;
+#endif
+
+
+#if 0
+int __cdecl main(int argc, char* argv[])
+{
+	int res;
+	unsigned char buf[65];
+
+	UNREFERENCED_PARAMETER(argc);
+	UNREFERENCED_PARAMETER(argv);
+
+	/* Set up the command buffer. */
+	memset(buf,0x00,sizeof(buf));
+	buf[0] = 0;
+	buf[1] = 0x81;
+	
+
+	/* Open the device. */
+	int handle = open(VendorID, ProductID, L"12345");
+	if (handle < 0)
+		printf("unable to open device\n");
+
+
+	/* Toggle LED (cmd 0x80) */
+	buf[1] = 0x80;
+	res = write(handle, buf, 65);
+	if (res < 0)
+		printf("Unable to write()\n");
+
+	/* Request state (cmd 0x81) */
+	buf[1] = 0x81;
+	write(handle, buf, 65);
+	if (res < 0)
+		printf("Unable to write() (2)\n");
+
+	/* Read requested state */
+	read(handle, buf, 65);
+	if (res < 0)
+		printf("Unable to read()\n");
+
+	/* Print out the returned buffer. */
+	for (int i = 0; i < 4; i++)
+		printf("buf[%d]: %d\n", i, buf[i]);
+
+	return 0;
+}
+#endif
+
+#ifdef __cplusplus
+} /* extern "C" */
+#endif