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@@ -0,0 +1,1011 @@
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+// Copyright 2018 The go-ethereum Authors
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+// This file is part of the go-ethereum library.
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+//
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+// The go-ethereum library is free software: you can redistribute it and/or modify
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+// it under the terms of the GNU Lesser General Public License as published by
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+// the Free Software Foundation, either version 3 of the License, or
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+// (at your option) any later version.
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+//
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+// The go-ethereum library is distributed in the hope that it will be useful,
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+// but WITHOUT ANY WARRANTY; without even the implied warranty of
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+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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+// GNU Lesser General Public License for more details.
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+//
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+// You should have received a copy of the GNU Lesser General Public License
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+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
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+
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+package scwallet
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+
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+import (
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+ "bytes"
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+ "context"
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+ "crypto/hmac"
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+ "crypto/sha256"
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+ "crypto/sha512"
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+ "encoding/asn1"
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+ "encoding/binary"
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+ "errors"
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+ "fmt"
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+ "math/big"
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+ "strings"
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+ "sync"
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+ "time"
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+
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+ "github.com/ebfe/scard"
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+ ethereum "github.com/ethereum/go-ethereum"
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+ "github.com/ethereum/go-ethereum/accounts"
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+ "github.com/ethereum/go-ethereum/common"
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+ "github.com/ethereum/go-ethereum/core/types"
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+ "github.com/ethereum/go-ethereum/crypto"
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+ "github.com/ethereum/go-ethereum/crypto/secp256k1"
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+ "github.com/ethereum/go-ethereum/log"
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+)
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+
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+var (
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+ APPLET_AID = []byte{0x53, 0x74, 0x61, 0x74, 0x75, 0x73, 0x57, 0x61, 0x6C, 0x6C, 0x65, 0x74, 0x41, 0x70, 0x70}
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+ AlreadyOpenError = errors.New("Wallet already open")
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+ PairingRequiredError = errors.New("Pairing required with personal.openWallet(puk)")
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+ PinRequiredError = errors.New("Must unlock with personal.openWallet(pin)")
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+ PubkeyMismatchError = errors.New("Could not recover matching public key from signature")
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+ WalletChangedError = errors.New("Smartcard has been changed")
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+ DerivationSignatureHash = sha256.Sum256([]byte("STATUS KEY DERIVATION"))
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+)
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+
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+const (
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+ CLA_SCWALLET = 0x80
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+ INS_VERIFY_PIN = 0x20
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+ INS_EXPORT_KEY = 0xC2
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+ INS_SIGN = 0xC0
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+ INS_LOAD_KEY = 0xD0
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+ INS_DERIVE_KEY = 0xD1
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+ INS_STATUS = 0xF2
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+ DERIVE_P1_ASSISTED = uint8(0x01)
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+ DERIVE_P1_APPEND = uint8(0x80)
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+ DERIVE_P2_KEY_PATH = uint8(0x00)
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+ DERIVE_P2_PUBLIC_KEY = uint8(0x01)
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+ STATUS_P1_WALLET_STATUS = uint8(0x00)
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+ STATUS_P1_PATH = uint8(0x01)
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+ SIGN_P1_PRECOMPUTED_HASH = uint8(0x01)
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+ SIGN_P2_ONLY_BLOCK = uint8(0x81)
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+ EXPORT_P1_ANY = uint8(0x00)
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+ EXPORT_P2_PUBKEY = uint8(0x01)
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+
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+ // Minimum time to wait between self derivation attempts, even it the user is
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+ // requesting accounts like crazy.
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+ selfDeriveThrottling = time.Second
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+)
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+
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+// Wallet represents a smartcard wallet instance.
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+type Wallet struct {
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+ Hub *Hub // A handle to the Hub that instantiated this wallet.
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+ PublicKey []byte // The wallet's public key (used for communication and identification, not signing!)
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+
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+ lock sync.Mutex // Lock that gates access to struct fields and communication with the card
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+ card *scard.Card // A handle to the smartcard interface for the wallet.
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+ session *Session // The secure communication session with the card
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+ log log.Logger // Contextual logger to tag the base with its id
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+ deriveNextPath accounts.DerivationPath // Next derivation path for account auto-discovery
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+ deriveNextAddr common.Address // Next derived account address for auto-discovery
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+ deriveChain ethereum.ChainStateReader // Blockchain state reader to discover used account with
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+ deriveReq chan chan struct{} // Channel to request a self-derivation on
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+ deriveQuit chan chan error // Channel to terminate the self-deriver with
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+}
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+
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+// NewWallet constructs and returns a new Wallet instance.
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+func NewWallet(hub *Hub, card *scard.Card) *Wallet {
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+ wallet := &Wallet{
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+ Hub: hub,
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+ card: card,
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+ }
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+ return wallet
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+}
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+
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+// transmit sends an APDU to the smartcard and receives and decodes the response.
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+// It automatically handles requests by the card to fetch the return data separately,
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+// and returns an error if the response status code is not success.
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+func transmit(card *scard.Card, command *CommandAPDU) (*ResponseAPDU, error) {
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+ data, err := command.serialize()
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+ if err != nil {
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+ return nil, err
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+ }
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+
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+ responseData, err := card.Transmit(data)
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+ if err != nil {
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+ return nil, err
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+ }
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+
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+ response := new(ResponseAPDU)
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+ if err = response.deserialize(responseData); err != nil {
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+ return nil, err
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+ }
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+
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+ // Are we being asked to fetch the response separately?
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+ if response.Sw1 == SW1_GET_RESPONSE && (command.Cla != CLA_ISO7816 || command.Ins != INS_GET_RESPONSE) {
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+ return transmit(card, &CommandAPDU{
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+ Cla: CLA_ISO7816,
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+ Ins: INS_GET_RESPONSE,
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+ P1: 0,
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+ P2: 0,
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+ Data: nil,
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+ Le: response.Sw2,
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+ })
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+ }
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+
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+ if response.Sw1 != SW1_OK {
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+ return nil, fmt.Errorf("Unexpected insecure response status Cla=0x%x, Ins=0x%x, Sw=0x%x%x", command.Cla, command.Ins, response.Sw1, response.Sw2)
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+ }
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+
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+ return response, nil
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+}
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+
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+// applicationInfo encodes information about the smartcard application - its
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+// instance UID and public key.
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+type applicationInfo struct {
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+ InstanceUID []byte `asn1:"tag:15"`
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+ PublicKey []byte `asn1:"tag:0"`
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+}
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+
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+// connect connects to the wallet application and establishes a secure channel with it.
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+// must be called before any other interaction with the wallet.
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+func (w *Wallet) connect() error {
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+ w.lock.Lock()
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+ defer w.lock.Unlock()
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+
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+ appinfo, err := w.doselect()
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+ if err != nil {
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+ return err
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+ }
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+
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+ channel, err := NewSecureChannelSession(w.card, appinfo.PublicKey)
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+ if err != nil {
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+ return err
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+ }
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+
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+ w.PublicKey = appinfo.PublicKey
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+ w.log = log.New("url", w.URL())
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+ w.session = &Session{
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+ Wallet: w,
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+ Channel: channel,
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+ }
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+ return nil
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+}
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+
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+// doselect is an internal (unlocked) function to send a SELECT APDU to the card.
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+func (w *Wallet) doselect() (*applicationInfo, error) {
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+ response, err := transmit(w.card, &CommandAPDU{
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+ Cla: CLA_ISO7816,
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+ Ins: INS_SELECT,
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+ P1: 4,
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+ P2: 0,
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+ Data: APPLET_AID,
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+ })
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+ if err != nil {
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+ return nil, err
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+ }
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+
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+ appinfo := new(applicationInfo)
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+ if _, err := asn1.UnmarshalWithParams(response.Data, appinfo, "tag:4"); err != nil {
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+ return nil, err
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+ }
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+ return appinfo, nil
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+}
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+
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+// ping checks the card's status and returns an error if unsuccessful.
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+func (w *Wallet) ping() error {
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+ w.lock.Lock()
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+ defer w.lock.Unlock()
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+
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+ if !w.session.paired() {
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+ // We can't ping if not paired
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+ return nil
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+ }
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+
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+ _, err := w.session.getWalletStatus()
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+ if err != nil {
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+ return err
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+ }
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+ return nil
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+}
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+
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+// release releases any resources held by an open wallet instance.
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+func (w *Wallet) release() error {
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+ if w.session != nil {
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+ return w.session.release()
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+ }
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+ return nil
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+}
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+
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+// pair is an internal (unlocked) function for establishing a new pairing
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+// with the wallet.
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+func (w *Wallet) pair(puk []byte) error {
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+ if w.session.paired() {
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+ return fmt.Errorf("Wallet already paired")
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+ }
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+
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+ pairing, err := w.session.pair(puk)
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+ if err != nil {
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+ return err
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+ }
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+
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+ if err = w.Hub.setPairing(w, &pairing); err != nil {
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+ return err
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+ }
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+
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+ return w.session.authenticate(pairing)
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+}
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+
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+// Unpair deletes an existing wallet pairing.
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+func (w *Wallet) Unpair(pin []byte) error {
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+ w.lock.Lock()
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+ defer w.lock.Unlock()
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+
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+ if !w.session.paired() {
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+ return fmt.Errorf("Wallet %x not paired", w.PublicKey)
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+ }
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+
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+ if err := w.session.verifyPin(pin); err != nil {
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+ return fmt.Errorf("Error verifying pin: %s", err)
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+ }
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+
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+ if err := w.session.unpair(); err != nil {
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+ return fmt.Errorf("Error unpairing: %s", err)
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+ }
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+
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+ if err := w.Hub.setPairing(w, nil); err != nil {
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+ return err
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+ }
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+
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+ return nil
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+}
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+
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+// URL retrieves the canonical path under which this wallet is reachable. It is
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+// user by upper layers to define a sorting order over all wallets from multiple
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+// backends.
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+func (w *Wallet) URL() accounts.URL {
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+ return accounts.URL{
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+ Scheme: w.Hub.scheme,
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+ Path: fmt.Sprintf("%x", w.PublicKey[1:3]),
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+ }
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+}
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+
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+// Status returns a textual status to aid the user in the current state of the
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+// wallet. It also returns an error indicating any failure the wallet might have
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+// encountered.
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+func (w *Wallet) Status() (string, error) {
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+ w.lock.Lock()
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+ defer w.lock.Unlock()
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+
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+ if !w.session.paired() {
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+ return "Unpaired", nil
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+ }
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+
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+ status, err := w.session.getWalletStatus()
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+ if err != nil {
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+ return "Error", err
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+ }
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+
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+ if w.session.verified {
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+ return fmt.Sprintf("Open, %s", status), nil
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+ } else {
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+ return fmt.Sprintf("Locked, %s", status), nil
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+ }
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+}
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+
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+// Open initializes access to a wallet instance. It is not meant to unlock or
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+// decrypt account keys, rather simply to establish a connection to hardware
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+// wallets and/or to access derivation seeds.
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+//
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+// The passphrase parameter may or may not be used by the implementation of a
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+// particular wallet instance. The reason there is no passwordless open method
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+// is to strive towards a uniform wallet handling, oblivious to the different
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+// backend providers.
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+//
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+// Please note, if you open a wallet, you must close it to release any allocated
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+// resources (especially important when working with hardware wallets).
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+func (w *Wallet) Open(passphrase string) error {
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+ w.lock.Lock()
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+ defer w.lock.Unlock()
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+
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+ if w.session.verified {
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+ // Already open
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+ return AlreadyOpenError
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+ }
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+
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+ if !w.session.paired() {
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+ // Unpaired.
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+ if pairing := w.Hub.getPairing(w); pairing != nil {
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+ // Authenticate with the existing pairing.
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+ if err := w.session.authenticate(*pairing); err != nil {
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+ return fmt.Errorf("Could not authenticate with paired card %x: %s", w.PublicKey[:4], err)
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+ }
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+ } else if passphrase != "" {
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+ // Establish a new pairing
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+ return w.pair([]byte(passphrase))
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+ } else {
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+ return PairingRequiredError
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+ }
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+ }
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+
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+ if passphrase == "" {
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+ return PinRequiredError
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+ }
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+ // Verify pin
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+ if err := w.session.verifyPin([]byte(passphrase)); err != nil {
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+ return err
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+ }
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+
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+ w.deriveReq = make(chan chan struct{})
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+ w.deriveQuit = make(chan chan error)
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+
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+ go w.selfDerive()
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+
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+ // Notify anyone listening for wallet events that a new device is accessible
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+ go w.Hub.updateFeed.Send(accounts.WalletEvent{Wallet: w, Kind: accounts.WalletOpened})
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+
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+ return nil
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+}
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+
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+// Close stops and closes the wallet, freeing any resources.
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+func (w *Wallet) Close() error {
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+ // Ensure the wallet was opened
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+ w.lock.Lock()
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+ dQuit := w.deriveQuit
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+ w.lock.Unlock()
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+
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+ // Terminate the self-derivations
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+ var derr error
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+ if dQuit != nil {
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+ errc := make(chan error)
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+ dQuit <- errc
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+ derr = <-errc // Save for later, we *must* close the USB
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+ }
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+ // Terminate the device connection
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+ w.lock.Lock()
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+ defer w.lock.Unlock()
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+
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+ w.deriveQuit = nil
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+ w.deriveReq = nil
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+
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+ if err := w.release(); err != nil {
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+ return err
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+ }
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+ return derr
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+}
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+
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+// selfDerive is an account derivation loop that upon request attempts to find
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+// new non-zero accounts.
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+func (w *Wallet) selfDerive() {
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+ w.log.Debug("Smartcard wallet self-derivation started")
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+ defer w.log.Debug("Smartcard wallet self-derivation stopped")
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+
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+ // Execute self-derivations until termination or error
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+ var (
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+ reqc chan struct{}
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+ errc chan error
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+ err error
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+ )
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+ for errc == nil && err == nil {
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+ // Wait until either derivation or termination is requested
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+ select {
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+ case errc = <-w.deriveQuit:
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+ // Termination requested
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+ continue
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+ case reqc = <-w.deriveReq:
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+ // Account discovery requested
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+ }
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+ // Derivation needs a chain and device access, skip if either unavailable
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+ w.lock.Lock()
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+ if w.session == nil || w.deriveChain == nil {
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+ w.lock.Unlock()
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+ reqc <- struct{}{}
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+ continue
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+ }
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+ pairing := w.Hub.getPairing(w)
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+
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+ // Device lock obtained, derive the next batch of accounts
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+ var (
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+ paths []accounts.DerivationPath
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+ nextAccount accounts.Account
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+ nextAddr = w.deriveNextAddr
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+ nextPath = w.deriveNextPath
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+
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+ context = context.Background()
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+ )
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+ for empty := false; !empty; {
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+ // Retrieve the next derived Ethereum account
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+ if nextAddr == (common.Address{}) {
|
|
|
+ if nextAccount, err = w.session.derive(nextPath); err != nil {
|
|
|
+ w.log.Warn("Smartcard wallet account derivation failed", "err", err)
|
|
|
+ break
|
|
|
+ }
|
|
|
+ nextAddr = nextAccount.Address
|
|
|
+ }
|
|
|
+ // Check the account's status against the current chain state
|
|
|
+ var (
|
|
|
+ balance *big.Int
|
|
|
+ nonce uint64
|
|
|
+ )
|
|
|
+ balance, err = w.deriveChain.BalanceAt(context, nextAddr, nil)
|
|
|
+ if err != nil {
|
|
|
+ w.log.Warn("Smartcard wallet balance retrieval failed", "err", err)
|
|
|
+ break
|
|
|
+ }
|
|
|
+ nonce, err = w.deriveChain.NonceAt(context, nextAddr, nil)
|
|
|
+ if err != nil {
|
|
|
+ w.log.Warn("Smartcard wallet nonce retrieval failed", "err", err)
|
|
|
+ break
|
|
|
+ }
|
|
|
+ // If the next account is empty, stop self-derivation, but add it nonetheless
|
|
|
+ if balance.Sign() == 0 && nonce == 0 {
|
|
|
+ empty = true
|
|
|
+ }
|
|
|
+ // We've just self-derived a new account, start tracking it locally
|
|
|
+ path := make(accounts.DerivationPath, len(nextPath))
|
|
|
+ copy(path[:], nextPath[:])
|
|
|
+ paths = append(paths, path)
|
|
|
+
|
|
|
+ // Display a log message to the user for new (or previously empty accounts)
|
|
|
+ if _, known := pairing.Accounts[nextAddr]; !known || (!empty && nextAddr == w.deriveNextAddr) {
|
|
|
+ w.log.Info("Smartcard wallet discovered new account", "address", nextAccount.Address, "path", path, "balance", balance, "nonce", nonce)
|
|
|
+ }
|
|
|
+ pairing.Accounts[nextAddr] = path
|
|
|
+
|
|
|
+ // Fetch the next potential account
|
|
|
+ if !empty {
|
|
|
+ nextAddr = common.Address{}
|
|
|
+ nextPath[len(nextPath)-1]++
|
|
|
+ }
|
|
|
+ }
|
|
|
+
|
|
|
+ // If there are new accounts, write them out
|
|
|
+ if len(paths) > 0 {
|
|
|
+ err = w.Hub.setPairing(w, pairing)
|
|
|
+ }
|
|
|
+
|
|
|
+ // Shift the self-derivation forward
|
|
|
+ w.deriveNextAddr = nextAddr
|
|
|
+ w.deriveNextPath = nextPath
|
|
|
+
|
|
|
+ // Self derivation complete, release device lock
|
|
|
+ w.lock.Unlock()
|
|
|
+
|
|
|
+ // Notify the user of termination and loop after a bit of time (to avoid trashing)
|
|
|
+ reqc <- struct{}{}
|
|
|
+ if err == nil {
|
|
|
+ select {
|
|
|
+ case errc = <-w.deriveQuit:
|
|
|
+ // Termination requested, abort
|
|
|
+ case <-time.After(selfDeriveThrottling):
|
|
|
+ // Waited enough, willing to self-derive again
|
|
|
+ }
|
|
|
+ }
|
|
|
+ }
|
|
|
+ // In case of error, wait for termination
|
|
|
+ if err != nil {
|
|
|
+ w.log.Debug("Smartcard wallet self-derivation failed", "err", err)
|
|
|
+ errc = <-w.deriveQuit
|
|
|
+ }
|
|
|
+ errc <- err
|
|
|
+}
|
|
|
+
|
|
|
+// Accounts retrieves the list of signing accounts the wallet is currently aware
|
|
|
+// of. For hierarchical deterministic wallets, the list will not be exhaustive,
|
|
|
+// rather only contain the accounts explicitly pinned during account derivation.
|
|
|
+func (w *Wallet) Accounts() []accounts.Account {
|
|
|
+ // Attempt self-derivation if it's running
|
|
|
+ reqc := make(chan struct{}, 1)
|
|
|
+ select {
|
|
|
+ case w.deriveReq <- reqc:
|
|
|
+ // Self-derivation request accepted, wait for it
|
|
|
+ <-reqc
|
|
|
+ default:
|
|
|
+ // Self-derivation offline, throttled or busy, skip
|
|
|
+ }
|
|
|
+
|
|
|
+ w.lock.Lock()
|
|
|
+ defer w.lock.Unlock()
|
|
|
+
|
|
|
+ if pairing := w.Hub.getPairing(w); pairing != nil {
|
|
|
+ ret := make([]accounts.Account, 0, len(pairing.Accounts))
|
|
|
+ for address, path := range pairing.Accounts {
|
|
|
+ ret = append(ret, w.makeAccount(address, path))
|
|
|
+ }
|
|
|
+ return ret
|
|
|
+ }
|
|
|
+ return nil
|
|
|
+}
|
|
|
+
|
|
|
+func (w *Wallet) makeAccount(address common.Address, path accounts.DerivationPath) accounts.Account {
|
|
|
+ return accounts.Account{
|
|
|
+ Address: address,
|
|
|
+ URL: accounts.URL{
|
|
|
+ Scheme: w.Hub.scheme,
|
|
|
+ Path: fmt.Sprintf("%x/%s", w.PublicKey[1:3], path.String()),
|
|
|
+ },
|
|
|
+ }
|
|
|
+}
|
|
|
+
|
|
|
+// Contains returns whether an account is part of this particular wallet or not.
|
|
|
+func (w *Wallet) Contains(account accounts.Account) bool {
|
|
|
+ if pairing := w.Hub.getPairing(w); pairing != nil {
|
|
|
+ _, ok := pairing.Accounts[account.Address]
|
|
|
+ return ok
|
|
|
+ }
|
|
|
+ return false
|
|
|
+}
|
|
|
+
|
|
|
+// Initialize installs a keypair generated from the provided key into the wallet.
|
|
|
+func (w *Wallet) Initialize(seed []byte) error {
|
|
|
+ w.lock.Lock()
|
|
|
+ defer w.lock.Unlock()
|
|
|
+
|
|
|
+ return w.session.initialize(seed)
|
|
|
+}
|
|
|
+
|
|
|
+// Derive attempts to explicitly derive a hierarchical deterministic account at
|
|
|
+// the specified derivation path. If requested, the derived account will be added
|
|
|
+// to the wallet's tracked account list.
|
|
|
+func (w *Wallet) Derive(path accounts.DerivationPath, pin bool) (accounts.Account, error) {
|
|
|
+ w.lock.Lock()
|
|
|
+ defer w.lock.Unlock()
|
|
|
+
|
|
|
+ account, err := w.session.derive(path)
|
|
|
+ if err != nil {
|
|
|
+ return accounts.Account{}, err
|
|
|
+ }
|
|
|
+
|
|
|
+ if pin {
|
|
|
+ pairing := w.Hub.getPairing(w)
|
|
|
+ pairing.Accounts[account.Address] = path
|
|
|
+ if err := w.Hub.setPairing(w, pairing); err != nil {
|
|
|
+ return accounts.Account{}, err
|
|
|
+ }
|
|
|
+ }
|
|
|
+
|
|
|
+ return account, nil
|
|
|
+}
|
|
|
+
|
|
|
+// SelfDerive sets a base account derivation path from which the wallet attempts
|
|
|
+// to discover non zero accounts and automatically add them to list of tracked
|
|
|
+// accounts.
|
|
|
+//
|
|
|
+// Note, self derivaton will increment the last component of the specified path
|
|
|
+// opposed to decending into a child path to allow discovering accounts starting
|
|
|
+// from non zero components.
|
|
|
+//
|
|
|
+// You can disable automatic account discovery by calling SelfDerive with a nil
|
|
|
+// chain state reader.
|
|
|
+func (w *Wallet) SelfDerive(base accounts.DerivationPath, chain ethereum.ChainStateReader) {
|
|
|
+ w.lock.Lock()
|
|
|
+ defer w.lock.Unlock()
|
|
|
+
|
|
|
+ w.deriveNextPath = make(accounts.DerivationPath, len(base))
|
|
|
+ copy(w.deriveNextPath[:], base[:])
|
|
|
+
|
|
|
+ w.deriveNextAddr = common.Address{}
|
|
|
+ w.deriveChain = chain
|
|
|
+}
|
|
|
+
|
|
|
+// SignHash requests the wallet to sign the given hash.
|
|
|
+//
|
|
|
+// It looks up the account specified either solely via its address contained within,
|
|
|
+// or optionally with the aid of any location metadata from the embedded URL field.
|
|
|
+//
|
|
|
+// If the wallet requires additional authentication to sign the request (e.g.
|
|
|
+// a password to decrypt the account, or a PIN code o verify the transaction),
|
|
|
+// an AuthNeededError instance will be returned, containing infos for the user
|
|
|
+// about which fields or actions are needed. The user may retry by providing
|
|
|
+// the needed details via SignHashWithPassphrase, or by other means (e.g. unlock
|
|
|
+// the account in a keystore).
|
|
|
+func (w *Wallet) SignHash(account accounts.Account, hash []byte) ([]byte, error) {
|
|
|
+ w.lock.Lock()
|
|
|
+ defer w.lock.Unlock()
|
|
|
+
|
|
|
+ path, err := w.findAccountPath(account)
|
|
|
+ if err != nil {
|
|
|
+ return nil, err
|
|
|
+ }
|
|
|
+
|
|
|
+ return w.session.sign(path, hash)
|
|
|
+}
|
|
|
+
|
|
|
+// SignTx requests the wallet to sign the given transaction.
|
|
|
+//
|
|
|
+// It looks up the account specified either solely via its address contained within,
|
|
|
+// or optionally with the aid of any location metadata from the embedded URL field.
|
|
|
+//
|
|
|
+// If the wallet requires additional authentication to sign the request (e.g.
|
|
|
+// a password to decrypt the account, or a PIN code o verify the transaction),
|
|
|
+// an AuthNeededError instance will be returned, containing infos for the user
|
|
|
+// about which fields or actions are needed. The user may retry by providing
|
|
|
+// the needed details via SignTxWithPassphrase, or by other means (e.g. unlock
|
|
|
+// the account in a keystore).
|
|
|
+func (w *Wallet) SignTx(account accounts.Account, tx *types.Transaction, chainID *big.Int) (*types.Transaction, error) {
|
|
|
+ signer := types.NewEIP155Signer(chainID)
|
|
|
+ hash := signer.Hash(tx)
|
|
|
+ sig, err := w.SignHash(account, hash[:])
|
|
|
+ if err != nil {
|
|
|
+ return nil, err
|
|
|
+ }
|
|
|
+ return tx.WithSignature(signer, sig)
|
|
|
+}
|
|
|
+
|
|
|
+// SignHashWithPassphrase requests the wallet to sign the given hash with the
|
|
|
+// given passphrase as extra authentication information.
|
|
|
+//
|
|
|
+// It looks up the account specified either solely via its address contained within,
|
|
|
+// or optionally with the aid of any location metadata from the embedded URL field.
|
|
|
+func (w *Wallet) SignHashWithPassphrase(account accounts.Account, passphrase string, hash []byte) ([]byte, error) {
|
|
|
+ if !w.session.verified {
|
|
|
+ if err := w.Open(passphrase); err != nil {
|
|
|
+ return nil, err
|
|
|
+ }
|
|
|
+ }
|
|
|
+
|
|
|
+ return w.SignHash(account, hash)
|
|
|
+}
|
|
|
+
|
|
|
+// SignTxWithPassphrase requests the wallet to sign the given transaction, with the
|
|
|
+// given passphrase as extra authentication information.
|
|
|
+//
|
|
|
+// It looks up the account specified either solely via its address contained within,
|
|
|
+// or optionally with the aid of any location metadata from the embedded URL field.
|
|
|
+func (w *Wallet) SignTxWithPassphrase(account accounts.Account, passphrase string, tx *types.Transaction, chainID *big.Int) (*types.Transaction, error) {
|
|
|
+ if !w.session.verified {
|
|
|
+ if err := w.Open(passphrase); err != nil {
|
|
|
+ return nil, err
|
|
|
+ }
|
|
|
+ }
|
|
|
+ return w.SignTx(account, tx, chainID)
|
|
|
+}
|
|
|
+
|
|
|
+// findAccountPath returns the derivation path for the provided account.
|
|
|
+// It first checks for the address in the list of pinned accounts, and if it is
|
|
|
+// not found, attempts to parse the derivation path from the account's URL.
|
|
|
+func (w *Wallet) findAccountPath(account accounts.Account) (accounts.DerivationPath, error) {
|
|
|
+ pairing := w.Hub.getPairing(w)
|
|
|
+ if path, ok := pairing.Accounts[account.Address]; ok {
|
|
|
+ return path, nil
|
|
|
+ }
|
|
|
+
|
|
|
+ // Look for the path in the URL
|
|
|
+ if account.URL.Scheme != w.Hub.scheme {
|
|
|
+ return nil, fmt.Errorf("Scheme %s does not match wallet scheme %s", account.URL.Scheme, w.Hub.scheme)
|
|
|
+ }
|
|
|
+
|
|
|
+ parts := strings.SplitN(account.URL.Path, "/", 2)
|
|
|
+ if len(parts) != 2 {
|
|
|
+ return nil, fmt.Errorf("Invalid URL format: %s", account.URL)
|
|
|
+ }
|
|
|
+
|
|
|
+ if parts[0] != fmt.Sprintf("%x", w.PublicKey[1:3]) {
|
|
|
+ return nil, fmt.Errorf("URL %s is not for this wallet", account.URL)
|
|
|
+ }
|
|
|
+
|
|
|
+ return accounts.ParseDerivationPath(parts[1])
|
|
|
+}
|
|
|
+
|
|
|
+// Session represents a secured communication session with the wallet
|
|
|
+type Session struct {
|
|
|
+ Wallet *Wallet // A handle to the wallet that opened the session
|
|
|
+ Channel *SecureChannelSession // A secure channel for encrypted messages
|
|
|
+ verified bool // Whether the pin has been verified in this session.
|
|
|
+}
|
|
|
+
|
|
|
+// pair establishes a new pairing over this channel, using the provided secret.
|
|
|
+func (s *Session) pair(secret []byte) (SmartcardPairing, error) {
|
|
|
+ err := s.Channel.Pair(secret)
|
|
|
+ if err != nil {
|
|
|
+ return SmartcardPairing{}, err
|
|
|
+ }
|
|
|
+
|
|
|
+ return SmartcardPairing{
|
|
|
+ PublicKey: s.Wallet.PublicKey,
|
|
|
+ PairingIndex: s.Channel.PairingIndex,
|
|
|
+ PairingKey: s.Channel.PairingKey,
|
|
|
+ Accounts: make(map[common.Address]accounts.DerivationPath),
|
|
|
+ }, nil
|
|
|
+}
|
|
|
+
|
|
|
+// unpair deletes an existing pairing
|
|
|
+func (s *Session) unpair() error {
|
|
|
+ if !s.verified {
|
|
|
+ return fmt.Errorf("Unpair requires that the PIN be verified")
|
|
|
+ }
|
|
|
+ return s.Channel.Unpair()
|
|
|
+}
|
|
|
+
|
|
|
+// verifyPin unlocks a wallet with the provided pin
|
|
|
+func (s *Session) verifyPin(pin []byte) error {
|
|
|
+ if _, err := s.Channel.TransmitEncrypted(CLA_SCWALLET, INS_VERIFY_PIN, 0, 0, pin); err != nil {
|
|
|
+ return err
|
|
|
+ }
|
|
|
+ s.verified = true
|
|
|
+ return nil
|
|
|
+}
|
|
|
+
|
|
|
+// release releases resources associated with the channel
|
|
|
+func (s *Session) release() error {
|
|
|
+ return s.Wallet.card.Disconnect(scard.LeaveCard)
|
|
|
+}
|
|
|
+
|
|
|
+// paired returns true if a valid pairing exists
|
|
|
+func (s *Session) paired() bool {
|
|
|
+ return s.Channel.PairingKey != nil
|
|
|
+}
|
|
|
+
|
|
|
+// authenticate uses an existing pairing to establish a secure channel
|
|
|
+func (s *Session) authenticate(pairing SmartcardPairing) error {
|
|
|
+ if !bytes.Equal(s.Wallet.PublicKey, pairing.PublicKey) {
|
|
|
+ return fmt.Errorf("Cannot pair using another wallet's pairing; %x != %x", s.Wallet.PublicKey, pairing.PublicKey)
|
|
|
+ }
|
|
|
+ s.Channel.PairingKey = pairing.PairingKey
|
|
|
+ s.Channel.PairingIndex = pairing.PairingIndex
|
|
|
+ return s.Channel.Open()
|
|
|
+}
|
|
|
+
|
|
|
+// walletStatus describes a smartcard wallet's status information
|
|
|
+type walletStatus struct {
|
|
|
+ PinRetryCount int // Number of remaining PIN retries
|
|
|
+ PukRetryCount int // Number of remaining PUK retries
|
|
|
+ Initialized bool // Whether the card has been initialized with a private key
|
|
|
+ SupportsPKDerivation bool // Whether the card supports doing public key derivation itself
|
|
|
+}
|
|
|
+
|
|
|
+func (w walletStatus) String() string {
|
|
|
+ return fmt.Sprintf("pinRetryCount=%d, pukRetryCount=%d, initialized=%t, supportsPkDerivation=%t", w.PinRetryCount, w.PukRetryCount, w.Initialized, w.SupportsPKDerivation)
|
|
|
+}
|
|
|
+
|
|
|
+// getWalletStatus fetches the wallet's status from the card
|
|
|
+func (s *Session) getWalletStatus() (*walletStatus, error) {
|
|
|
+ response, err := s.Channel.TransmitEncrypted(CLA_SCWALLET, INS_STATUS, STATUS_P1_WALLET_STATUS, 0, nil)
|
|
|
+ if err != nil {
|
|
|
+ return nil, err
|
|
|
+ }
|
|
|
+
|
|
|
+ status := new(walletStatus)
|
|
|
+ if _, err := asn1.UnmarshalWithParams(response.Data, status, "tag:3"); err != nil {
|
|
|
+ return nil, err
|
|
|
+ }
|
|
|
+
|
|
|
+ return status, nil
|
|
|
+}
|
|
|
+
|
|
|
+// getDerivationPath fetches the wallet's current derivation path from the card
|
|
|
+func (s *Session) getDerivationPath() (accounts.DerivationPath, error) {
|
|
|
+ response, err := s.Channel.TransmitEncrypted(CLA_SCWALLET, INS_STATUS, STATUS_P1_PATH, 0, nil)
|
|
|
+ if err != nil {
|
|
|
+ return nil, err
|
|
|
+ }
|
|
|
+
|
|
|
+ buf := bytes.NewReader(response.Data)
|
|
|
+ path := make(accounts.DerivationPath, len(response.Data)/4)
|
|
|
+ return path, binary.Read(buf, binary.BigEndian, &path)
|
|
|
+}
|
|
|
+
|
|
|
+// initializeData contains data needed to initialize the smartcard wallet
|
|
|
+type initializeData struct {
|
|
|
+ PublicKey []byte `asn1:"tag:0"`
|
|
|
+ PrivateKey []byte `asn1:"tag:1"`
|
|
|
+ ChainCode []byte `asn1:"tag:2"`
|
|
|
+}
|
|
|
+
|
|
|
+// initialize initializes the card with new key data
|
|
|
+func (s *Session) initialize(seed []byte) error {
|
|
|
+ // HMAC the seed to produce the private key and chain code
|
|
|
+ mac := hmac.New(sha512.New, []byte("Bitcoin seed"))
|
|
|
+ mac.Write(seed)
|
|
|
+ seed = mac.Sum(nil)
|
|
|
+
|
|
|
+ key, err := crypto.ToECDSA(seed[:32])
|
|
|
+ if err != nil {
|
|
|
+ return err
|
|
|
+ }
|
|
|
+
|
|
|
+ id := initializeData{}
|
|
|
+ id.PublicKey = crypto.FromECDSAPub(&key.PublicKey)
|
|
|
+ id.PrivateKey = seed[:32]
|
|
|
+ id.ChainCode = seed[32:]
|
|
|
+ data, err := asn1.Marshal(id)
|
|
|
+ if err != nil {
|
|
|
+ return err
|
|
|
+ }
|
|
|
+
|
|
|
+ // Nasty hack to force the top-level struct tag to be context-specific
|
|
|
+ data[0] = 0xA1
|
|
|
+
|
|
|
+ _, err = s.Channel.TransmitEncrypted(CLA_SCWALLET, INS_LOAD_KEY, 0x02, 0, data)
|
|
|
+ return err
|
|
|
+}
|
|
|
+
|
|
|
+// derive derives a new HD key path on the card
|
|
|
+func (s *Session) derive(path accounts.DerivationPath) (accounts.Account, error) {
|
|
|
+ // If the current path is a prefix of the desired path, we don't have to
|
|
|
+ // start again.
|
|
|
+ remainingPath := path
|
|
|
+
|
|
|
+ pubkey, err := s.getPublicKey()
|
|
|
+ if err != nil {
|
|
|
+ return accounts.Account{}, err
|
|
|
+ }
|
|
|
+ currentPath, err := s.getDerivationPath()
|
|
|
+ if err != nil {
|
|
|
+ return accounts.Account{}, err
|
|
|
+ }
|
|
|
+
|
|
|
+ reset := false
|
|
|
+ if len(currentPath) <= len(path) {
|
|
|
+ for i := 0; i < len(currentPath); i++ {
|
|
|
+ if path[i] != currentPath[i] {
|
|
|
+ reset = true
|
|
|
+ break
|
|
|
+ }
|
|
|
+ }
|
|
|
+ if !reset {
|
|
|
+ remainingPath = path[len(currentPath):]
|
|
|
+ }
|
|
|
+ } else {
|
|
|
+ reset = true
|
|
|
+ }
|
|
|
+
|
|
|
+ for _, pathComponent := range remainingPath {
|
|
|
+ pubkey, err = s.deriveKeyAssisted(reset, pathComponent)
|
|
|
+ reset = false
|
|
|
+ if err != nil {
|
|
|
+ return accounts.Account{}, err
|
|
|
+ }
|
|
|
+ }
|
|
|
+ return s.Wallet.makeAccount(crypto.PubkeyToAddress(*crypto.ToECDSAPub(pubkey)), path), nil
|
|
|
+}
|
|
|
+
|
|
|
+// keyDerivationInfo contains information on the current key derivation step
|
|
|
+type keyDerivationInfo struct {
|
|
|
+ PublicKeyX []byte `asn1:"tag:3"` // The X coordinate of the current public key
|
|
|
+ Signature struct {
|
|
|
+ R *big.Int
|
|
|
+ S *big.Int
|
|
|
+ }
|
|
|
+}
|
|
|
+
|
|
|
+// deriveKeyAssisted does one step of assisted key generation, asking the card to generate
|
|
|
+// a specific path, and performing the necessary computations to finish the public key
|
|
|
+// generation step.
|
|
|
+func (s *Session) deriveKeyAssisted(reset bool, pathComponent uint32) ([]byte, error) {
|
|
|
+ p1 := DERIVE_P1_ASSISTED
|
|
|
+ if !reset {
|
|
|
+ p1 |= DERIVE_P1_APPEND
|
|
|
+ }
|
|
|
+
|
|
|
+ buf := new(bytes.Buffer)
|
|
|
+ if err := binary.Write(buf, binary.BigEndian, pathComponent); err != nil {
|
|
|
+ return nil, err
|
|
|
+ }
|
|
|
+ response, err := s.Channel.TransmitEncrypted(CLA_SCWALLET, INS_DERIVE_KEY, p1, DERIVE_P2_KEY_PATH, buf.Bytes())
|
|
|
+ if err != nil {
|
|
|
+ return nil, err
|
|
|
+ }
|
|
|
+
|
|
|
+ keyinfo := new(keyDerivationInfo)
|
|
|
+ if _, err := asn1.UnmarshalWithParams(response.Data, keyinfo, "tag:2"); err != nil {
|
|
|
+ return nil, err
|
|
|
+ }
|
|
|
+
|
|
|
+ rbytes, sbytes := keyinfo.Signature.R.Bytes(), keyinfo.Signature.S.Bytes()
|
|
|
+ sig := make([]byte, 65)
|
|
|
+ copy(sig[32-len(rbytes):32], rbytes)
|
|
|
+ copy(sig[64-len(sbytes):64], sbytes)
|
|
|
+
|
|
|
+ pubkey, err := determinePublicKey(sig, keyinfo.PublicKeyX)
|
|
|
+ if err != nil {
|
|
|
+ return nil, err
|
|
|
+ }
|
|
|
+
|
|
|
+ _, err = s.Channel.TransmitEncrypted(CLA_SCWALLET, INS_DERIVE_KEY, DERIVE_P1_ASSISTED|DERIVE_P1_APPEND, DERIVE_P2_PUBLIC_KEY, pubkey)
|
|
|
+ if err != nil {
|
|
|
+ return nil, err
|
|
|
+ }
|
|
|
+
|
|
|
+ return pubkey, nil
|
|
|
+}
|
|
|
+
|
|
|
+// keyExport contains information on an exported keypair
|
|
|
+type keyExport struct {
|
|
|
+ PublicKey []byte `asn1:"tag:0"`
|
|
|
+ PrivateKey []byte `asn1:"tag:1,optional"`
|
|
|
+}
|
|
|
+
|
|
|
+// getPublicKey returns the public key for the current derivation path
|
|
|
+func (s *Session) getPublicKey() ([]byte, error) {
|
|
|
+ response, err := s.Channel.TransmitEncrypted(CLA_SCWALLET, INS_EXPORT_KEY, EXPORT_P1_ANY, EXPORT_P2_PUBKEY, nil)
|
|
|
+ if err != nil {
|
|
|
+ return nil, err
|
|
|
+ }
|
|
|
+
|
|
|
+ keys := new(keyExport)
|
|
|
+ if _, err := asn1.UnmarshalWithParams(response.Data, keys, "tag:1"); err != nil {
|
|
|
+ return nil, err
|
|
|
+ }
|
|
|
+
|
|
|
+ return keys.PublicKey, nil
|
|
|
+}
|
|
|
+
|
|
|
+// signatureData contains information on a signature - the signature itself and
|
|
|
+// the corresponding public key
|
|
|
+type signatureData struct {
|
|
|
+ PublicKey []byte `asn1:"tag:0"`
|
|
|
+ Signature struct {
|
|
|
+ R *big.Int
|
|
|
+ S *big.Int
|
|
|
+ }
|
|
|
+}
|
|
|
+
|
|
|
+// sign asks the card to sign a message, and returns a valid signature after
|
|
|
+// recovering the v value.
|
|
|
+func (s *Session) sign(path accounts.DerivationPath, hash []byte) ([]byte, error) {
|
|
|
+ startTime := time.Now()
|
|
|
+ _, err := s.derive(path)
|
|
|
+ if err != nil {
|
|
|
+ return nil, err
|
|
|
+ }
|
|
|
+ deriveTime := time.Now()
|
|
|
+
|
|
|
+ response, err := s.Channel.TransmitEncrypted(CLA_SCWALLET, INS_SIGN, SIGN_P1_PRECOMPUTED_HASH, SIGN_P2_ONLY_BLOCK, hash)
|
|
|
+ if err != nil {
|
|
|
+ return nil, err
|
|
|
+ }
|
|
|
+
|
|
|
+ sigdata := new(signatureData)
|
|
|
+ if _, err := asn1.UnmarshalWithParams(response.Data, sigdata, "tag:0"); err != nil {
|
|
|
+ return nil, err
|
|
|
+ }
|
|
|
+
|
|
|
+ // Serialize the signature
|
|
|
+ rbytes, sbytes := sigdata.Signature.R.Bytes(), sigdata.Signature.S.Bytes()
|
|
|
+ sig := make([]byte, 65)
|
|
|
+ copy(sig[32-len(rbytes):32], rbytes)
|
|
|
+ copy(sig[64-len(sbytes):64], sbytes)
|
|
|
+
|
|
|
+ // Recover the V value.
|
|
|
+ sig, err = makeRecoverableSignature(hash, sig, sigdata.PublicKey)
|
|
|
+ if err != nil {
|
|
|
+ return nil, err
|
|
|
+ }
|
|
|
+
|
|
|
+ log.Debug("Signed using smartcard", "deriveTime", deriveTime.Sub(startTime), "signingTime", time.Since(deriveTime))
|
|
|
+
|
|
|
+ return sig, nil
|
|
|
+}
|
|
|
+
|
|
|
+// determinePublicKey uses a signature and the X component of a public key to
|
|
|
+// recover the entire public key.
|
|
|
+func determinePublicKey(sig, pubkeyX []byte) ([]byte, error) {
|
|
|
+ for v := 0; v < 2; v++ {
|
|
|
+ sig[64] = byte(v)
|
|
|
+ pubkey, err := crypto.Ecrecover(DerivationSignatureHash[:], sig)
|
|
|
+ if err == nil {
|
|
|
+ if bytes.Compare(pubkey[1:33], pubkeyX) == 0 {
|
|
|
+ return pubkey, nil
|
|
|
+ }
|
|
|
+ } else if v == 1 || err != secp256k1.ErrRecoverFailed {
|
|
|
+ return nil, err
|
|
|
+ }
|
|
|
+ }
|
|
|
+ return nil, PubkeyMismatchError
|
|
|
+}
|
|
|
+
|
|
|
+// makeRecoverableSignature uses a signature and an expected public key to
|
|
|
+// recover the v value and produce a recoverable signature.
|
|
|
+func makeRecoverableSignature(hash, sig, expectedPubkey []byte) ([]byte, error) {
|
|
|
+ for v := 0; v < 2; v++ {
|
|
|
+ sig[64] = byte(v)
|
|
|
+ pubkey, err := crypto.Ecrecover(hash, sig)
|
|
|
+ if err == nil {
|
|
|
+ if bytes.Compare(pubkey, expectedPubkey) == 0 {
|
|
|
+ return sig, nil
|
|
|
+ }
|
|
|
+ } else if v == 1 || err != secp256k1.ErrRecoverFailed {
|
|
|
+ return nil, err
|
|
|
+ }
|
|
|
+ }
|
|
|
+ return nil, PubkeyMismatchError
|
|
|
+}
|