README ¶
Using the smartcard wallet
Requirements
- A USB smartcard reader
- A keycard that supports the status app
- PCSCD version 4.3 running on your system Only version 4.3 is currently supported
Preparing the smartcard
WARNING: FOILLOWING THESE INSTRUCTIONS WILL DESTROY THE MASTER KEY ON YOUR CARD. ONLY PROCEED IF NO FUNDS ARE ASSOCIATED WITH THESE ACCOUNTS
You can use status' keycard-cli and you should get at least version 2.1.1 of their smartcard application
You also need to make sure that the PCSC daemon is running on your system.
Then, you can install the application to the card by typing:
keycard install -a keycard_v2.2.1.cap && keycard init
At the end of this process, you will be provided with a PIN, a PUK and a pairing password. Write them down, you'll need them shortly.
Start geth
with the console
command. You will notice the following warning:
WARN [04-09|16:58:38.898] Failed to open wallet url=keycard://044def09 err="smartcard: pairing password needed"
Write down the URL (keycard://044def09
in this example). Then ask geth
to open the wallet:
> personal.openWallet("keycard://044def09", "pairing password")
The pairing password has been generated during the card initialization process.
The process needs to be repeated once more with the PIN:
> personal.openWallet("keycard://044def09", "PIN number")
If everything goes well, you should see your new account when typing personal
on the console:
> personal
WARN [04-09|17:02:07.330] Smartcard wallet account derivation failed url=keycard://044def09 err="Unexpected response status Cla=0x80, Ins=0xd1, Sw=0x6985"
{
listAccounts: [],
listWallets: [{
status: "Empty, waiting for initialization",
url: "keycard://044def09"
}],
...
}
So the communication with the card is working, but there is no key associated with this wallet. Let's create it:
> personal.initializeWallet("keycard://044def09")
"tilt ... impact"
You should get a list of words, this is your seed so write them down. Your wallet should now be initialized:
> personal.listWallets
[{
accounts: [{
address: "0x678b7cd55c61917defb23546a41803c5bfefbc7a",
url: "keycard://044d/m/44'/60'/0'/0/0"
}],
status: "Online",
url: "keycard://044def09"
}]
You're all set!
Usage
- Start
geth
with theconsole
command - Check the card's URL by checking
personal.listWallets
:
listWallets: [{
status: "Online, can derive public keys",
url: "keycard://a4d73015"
}]
- Open the wallet, you will be prompted for your pairing password, then PIN:
personal.openWallet("keycard://a4d73015")
- Check that creation was successful by typing e.g.
personal
. Then use it like a regular wallet.
Known issues
- Starting geth with a valid card seems to make firefox crash.
- PCSC version 4.4 should work, but is currently untested
Documentation ¶
Index ¶
- Constants
- Variables
- type Hub
- type SecureChannelSession
- type Session
- type Wallet
- func (w *Wallet) Accounts() []accounts.Account
- func (w *Wallet) Close() error
- func (w *Wallet) Contains(account accounts.Account) bool
- func (w *Wallet) Derive(path accounts.DerivationPath, pin bool) (accounts.Account, error)
- func (w *Wallet) Initialize(seed []byte) error
- func (w *Wallet) Open(passphrase string) error
- func (w *Wallet) SelfDerive(bases []accounts.DerivationPath, chain ethereum.ChainStateReader)
- func (w *Wallet) SignData(account accounts.Account, mimeType string, data []byte) ([]byte, error)
- func (w *Wallet) SignDataWithPassphrase(account accounts.Account, passphrase, mimeType string, data []byte) ([]byte, error)
- func (w *Wallet) SignText(account accounts.Account, text []byte) ([]byte, error)
- func (w *Wallet) SignTextWithPassphrase(account accounts.Account, passphrase string, text []byte) ([]byte, error)
- func (w *Wallet) SignTx(account accounts.Account, tx *types.Transaction, chainID *big.Int) (*types.Transaction, error)
- func (w *Wallet) SignTxWithPassphrase(account accounts.Account, passphrase string, tx *types.Transaction, ...) (*types.Transaction, error)
- func (w *Wallet) Status() (string, error)
- func (w *Wallet) URL() accounts.URL
- func (w *Wallet) Unpair(pin []byte) error
Constants ¶
const ( P1DeriveKeyFromMaster = uint8(0x00) P1DeriveKeyFromParent = uint8(0x01) P1DeriveKeyFromCurrent = uint8(0x10) )
List of ADPU command parameters
const Scheme = "keycard"
Scheme is the URI prefix for smartcard wallets.
Variables ¶
var ( // DerivationSignatureHash is used to derive the public key from the signature of this hash DerivationSignatureHash = sha256.Sum256(common.Hash{}.Bytes()) )
var ErrAlreadyOpen = errors.New("smartcard: already open")
ErrAlreadyOpen is returned if the smart card is attempted to be opened, but there is already a paired and unlocked session.
var ErrPINNeeded = errors.New("smartcard: pin needed")
ErrPINNeeded is returned if opening the smart card requires a PIN code. In this case, the calling application should request user input to enter the PIN and send it back.
var ErrPINUnblockNeeded = errors.New("smartcard: pin unblock needed")
ErrPINUnblockNeeded is returned if opening the smart card requires a PIN code, but all PIN attempts have already been exhausted. In this case the calling application should request user input for the PUK and a new PIN code to set fo the card.
var ErrPairingPasswordNeeded = errors.New("smartcard: pairing password needed")
ErrPairingPasswordNeeded is returned if opening the smart card requires pairing with a pairing password. In this case, the calling application should request user input to enter the pairing password and send it back.
var ErrPubkeyMismatch = errors.New("smartcard: recovered public key mismatch")
ErrPubkeyMismatch is returned if the public key recovered from a signature does not match the one expected by the user.
Functions ¶
This section is empty.
Types ¶
type Hub ¶
type Hub struct {
// contains filtered or unexported fields
}
Hub is a accounts.Backend that can find and handle generic PC/SC hardware wallets.
func (*Hub) Subscribe ¶
func (hub *Hub) Subscribe(sink chan<- accounts.WalletEvent) event.Subscription
Subscribe implements accounts.Backend, creating an async subscription to receive notifications on the addition or removal of smart card wallets.
type SecureChannelSession ¶
type SecureChannelSession struct { PairingKey []byte // A permanent shared secret for a pairing, if present PairingIndex uint8 // The pairing index // contains filtered or unexported fields }
SecureChannelSession enables secure communication with a hardware wallet.
func NewSecureChannelSession ¶
func NewSecureChannelSession(card *pcsc.Card, keyData []byte) (*SecureChannelSession, error)
NewSecureChannelSession creates a new secure channel for the given card and public key.
func (*SecureChannelSession) Open ¶
func (s *SecureChannelSession) Open() error
Open initializes the secure channel.
func (*SecureChannelSession) Pair ¶
func (s *SecureChannelSession) Pair(pairingPassword []byte) error
Pair establishes a new pairing with the smartcard.
func (*SecureChannelSession) Unpair ¶
func (s *SecureChannelSession) Unpair() error
Unpair disestablishes an existing pairing.
type Session ¶
type Session struct { Wallet *Wallet // A handle to the wallet that opened the session Channel *SecureChannelSession // A secure channel for encrypted messages // contains filtered or unexported fields }
Session represents a secured communication session with the wallet.
type Wallet ¶
type Wallet struct { Hub *Hub // A handle to the Hub that instantiated this wallet. PublicKey []byte // The wallet's public key (used for communication and identification, not signing!) // contains filtered or unexported fields }
Wallet represents a smartcard wallet instance.
func (*Wallet) Accounts ¶
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 (*Wallet) Contains ¶
Contains returns whether an account is part of this particular wallet or not.
func (*Wallet) Derive ¶
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 (*Wallet) Initialize ¶
Initialize installs a keypair generated from the provided key into the wallet.
func (*Wallet) Open ¶
Open initializes access to a wallet instance. It is not meant to unlock or decrypt account keys, rather simply to establish a connection to hardware wallets and/or to access derivation seeds.
The passphrase parameter may or may not be used by the implementation of a particular wallet instance. The reason there is no passwordless open method is to strive towards a uniform wallet handling, oblivious to the different backend providers.
Please note, if you open a wallet, you must close it to release any allocated resources (especially important when working with hardware wallets).
func (*Wallet) SelfDerive ¶
func (w *Wallet) SelfDerive(bases []accounts.DerivationPath, chain ethereum.ChainStateReader)
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 derivation will increment the last component of the specified path opposed to descending into a child path to allow discovering accounts starting from non zero components.
Some hardware wallets switched derivation paths through their evolution, so this method supports providing multiple bases to discover old user accounts too. Only the last base will be used to derive the next empty account.
You can disable automatic account discovery by calling SelfDerive with a nil chain state reader.
func (*Wallet) SignData ¶
SignData requests the wallet to sign the hash of the given data.
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 SignDataWithPassphrase, or by other means (e.g. unlock the account in a keystore).
func (*Wallet) SignDataWithPassphrase ¶
func (w *Wallet) SignDataWithPassphrase(account accounts.Account, passphrase, mimeType string, data []byte) ([]byte, error)
SignDataWithPassphrase 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 (*Wallet) SignText ¶
SignText requests the wallet to sign the hash of a given piece of data, prefixed by the Ethereum prefix scheme 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 (*Wallet) SignTextWithPassphrase ¶
func (w *Wallet) SignTextWithPassphrase(account accounts.Account, passphrase string, text []byte) ([]byte, error)
SignTextWithPassphrase implements accounts.Wallet, attempting to sign the given hash with the given account using passphrase as extra authentication
func (*Wallet) SignTx ¶
func (w *Wallet) SignTx(account accounts.Account, tx *types.Transaction, chainID *big.Int) (*types.Transaction, error)
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 (*Wallet) SignTxWithPassphrase ¶
func (w *Wallet) SignTxWithPassphrase(account accounts.Account, passphrase string, tx *types.Transaction, chainID *big.Int) (*types.Transaction, error)
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 (*Wallet) Status ¶
Status returns a textual status to aid the user in the current state of the wallet. It also returns an error indicating any failure the wallet might have encountered.