Merge branch 'multi-coin'

1 files changed, 222 insertions, 0 deletions

diff --git a/accounts/accounts.go b/accounts/accounts.go
new file mode 100644
index 0000000..bca3223
--- /dev/null
+++ b/accounts/accounts.go
@@ -0,0 +1,222 @@
+// Copyright 2017 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+// Package accounts implements high level Ethereum account management.
+package accounts
+
+import (
+	"fmt"
+	"math/big"
+
+	"github.com/ava-labs/coreth/core/types"
+	ethereum "github.com/ava-labs/go-ethereum"
+	"github.com/ava-labs/go-ethereum/common"
+	"github.com/ava-labs/go-ethereum/event"
+	"golang.org/x/crypto/sha3"
+)
+
+// Account represents an Ethereum account located at a specific location defined
+// by the optional URL field.
+type Account struct {
+	Address common.Address `json:"address"` // Ethereum account address derived from the key
+	URL     URL            `json:"url"`     // Optional resource locator within a backend
+}
+
+const (
+	MimetypeDataWithValidator = "data/validator"
+	MimetypeTypedData         = "data/typed"
+	MimetypeClique            = "application/x-clique-header"
+	MimetypeTextPlain         = "text/plain"
+)
+
+// Wallet represents a software or hardware wallet that might contain one or more
+// accounts (derived from the same seed).
+type Wallet interface {
+	// URL retrieves the canonical path under which this wallet is reachable. It is
+	// user by upper layers to define a sorting order over all wallets from multiple
+	// backends.
+	URL() URL
+
+	// 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.
+	Status() (string, error)
+
+	// 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).
+	Open(passphrase string) error
+
+	// Close releases any resources held by an open wallet instance.
+	Close() error
+
+	// 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.
+	Accounts() []Account
+
+	// Contains returns whether an account is part of this particular wallet or not.
+	Contains(account Account) bool
+
+	// 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.
+	Derive(path DerivationPath, pin bool) (Account, error)
+
+	// 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.
+	//
+	// 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.
+	SelfDerive(bases []DerivationPath, chain ethereum.ChainStateReader)
+
+	// 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).
+	SignData(account Account, mimeType string, data []byte) ([]byte, error)
+
+	// SignDataWithPassphrase is identical to SignData, but also takes a password
+	// NOTE: there's an chance that an erroneous call might mistake the two strings, and
+	// supply password in the mimetype field, or vice versa. Thus, an implementation
+	// should never echo the mimetype or return the mimetype in the error-response
+	SignDataWithPassphrase(account Account, passphrase, mimeType string, data []byte) ([]byte, error)
+
+	// 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).
+	SignText(account Account, text []byte) ([]byte, error)
+
+	// SignTextWithPassphrase is identical to Signtext, but also takes a password
+	SignTextWithPassphrase(account Account, passphrase string, hash []byte) ([]byte, 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 to 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).
+	SignTx(account Account, tx *types.Transaction, chainID *big.Int) (*types.Transaction, error)
+
+	// SignTxWithPassphrase is identical to SignTx, but also takes a password
+	SignTxWithPassphrase(account Account, passphrase string, tx *types.Transaction, chainID *big.Int) (*types.Transaction, error)
+}
+
+// Backend is a "wallet provider" that may contain a batch of accounts they can
+// sign transactions with and upon request, do so.
+type Backend interface {
+	// Wallets retrieves the list of wallets the backend is currently aware of.
+	//
+	// The returned wallets are not opened by default. For software HD wallets this
+	// means that no base seeds are decrypted, and for hardware wallets that no actual
+	// connection is established.
+	//
+	// The resulting wallet list will be sorted alphabetically based on its internal
+	// URL assigned by the backend. Since wallets (especially hardware) may come and
+	// go, the same wallet might appear at a different positions in the list during
+	// subsequent retrievals.
+	Wallets() []Wallet
+
+	// Subscribe creates an async subscription to receive notifications when the
+	// backend detects the arrival or departure of a wallet.
+	Subscribe(sink chan<- WalletEvent) event.Subscription
+}
+
+// TextHash is a helper function that calculates a hash for the given message that can be
+// safely used to calculate a signature from.
+//
+// The hash is calulcated as
+//   keccak256("\x19Ethereum Signed Message:\n"${message length}${message}).
+//
+// This gives context to the signed message and prevents signing of transactions.
+func TextHash(data []byte) []byte {
+	hash, _ := TextAndHash(data)
+	return hash
+}
+
+// TextAndHash is a helper function that calculates a hash for the given message that can be
+// safely used to calculate a signature from.
+//
+// The hash is calulcated as
+//   keccak256("\x19Ethereum Signed Message:\n"${message length}${message}).
+//
+// This gives context to the signed message and prevents signing of transactions.
+func TextAndHash(data []byte) ([]byte, string) {
+	msg := fmt.Sprintf("\x19Ethereum Signed Message:\n%d%s", len(data), string(data))
+	hasher := sha3.NewLegacyKeccak256()
+	hasher.Write([]byte(msg))
+	return hasher.Sum(nil), msg
+}
+
+// WalletEventType represents the different event types that can be fired by
+// the wallet subscription subsystem.
+type WalletEventType int
+
+const (
+	// WalletArrived is fired when a new wallet is detected either via USB or via
+	// a filesystem event in the keystore.
+	WalletArrived WalletEventType = iota
+
+	// WalletOpened is fired when a wallet is successfully opened with the purpose
+	// of starting any background processes such as automatic key derivation.
+	WalletOpened
+
+	// WalletDropped
+	WalletDropped
+)
+
+// WalletEvent is an event fired by an account backend when a wallet arrival or
+// departure is detected.
+type WalletEvent struct {
+	Wallet Wallet          // Wallet instance arrived or departed
+	Kind   WalletEventType // Event type that happened in the system
+}