// 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/ethereum/go-ethereum" gethaccounts "github.com/ethereum/go-ethereum/accounts" "github.com/ethereum/go-ethereum/common" "github.com/ethereum/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). // // This method should return the signature in 'canonical' format, with v 0 or 1 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 = gethaccounts.WalletEventType 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 }