@compound-finance/ethereumjs-wallet

ethereumjs-wallet

or #ethereumjs on freenode

A lightweight wallet implementation. At the moment it supports key creation and conversion between various formats.

It is complemented by the following packages:

• ethereumjs-tx to sign transactions
• ethereumjs-icap to manipulate ICAP addresses
• store.js to use browser storage

Motivations are:

• be lightweight
• work in a browser
• use a single, maintained version of crypto library (and that should be in line with ethereumjs-util and ethereumjs-tx)
• support import/export between various wallet formats
• support BIP32 HD keys

Features not supported:

• signing transactions
• managing storage (neither in node.js or the browser)

Wallet API

Constructors:

• generate([icap]) - create an instance based on a new random key (setting icap to true will generate an address suitable for the ICAP Direct mode)
• generateVanityAddress(pattern) - create an instance where the address is valid against the supplied pattern (this will be very slow)
• fromPrivateKey(input) - create an instance based on a raw private key
• fromExtendedPrivateKey(input) - create an instance based on a BIP32 extended private key (xprv)
• fromPublicKey(input, [nonStrict]) - create an instance based on a public key (certain methods will not be available)
• fromExtendedPublicKey(input) - create an instance based on a BIP32 extended public key (xpub)
• fromV1(input, password) - import a wallet (Version 1 of the Ethereum wallet format)
• fromV3(input, password, [nonStrict]) - import a wallet (Version 3 of the Ethereum wallet format). Set nonStrict true to accept files with mixed-caps.
• fromEthSale(input, password) - import an Ethereum Pre Sale wallet

For the V1, V3 and EthSale formats the input is a JSON serialized string. All these formats require a password.

Note: fromPublicKey() only accepts uncompressed Ethereum-style public keys, unless the nonStrict flag is set to true.

Instance methods:

• getPrivateKey() - return the private key
• getPublicKey() - return the public key
• getAddress() - return the address
• getChecksumAddressString() - return the address with checksum
• getV3Filename([timestamp]) - return the suggested filename for V3 keystores
• toV3(password, [options]) - return the wallet as a JSON string (Version 3 of the Ethereum wallet format)

All of the above instance methods return a Buffer or JSON. Use the String suffixed versions for a string output, such as getPrivateKeyString().

Note: getPublicKey() only returns uncompressed Ethereum-style public keys.

Thirdparty API

Importing various third party wallets is possible through the thirdparty submodule:

var thirdparty = require('ethereumjs-wallet/thirdparty')

Constructors:

• fromEtherCamp(passphrase) - import a brain wallet used by Ether.Camp
• fromEtherWallet(input, password) - import a wallet generated by EtherWallet
• fromKryptoKit(seed) - import a wallet from a KryptoKit seed
• fromQuorumWallet(passphrase, userid) - import a brain wallet used by Quorum Wallet

HD Wallet API

To use BIP32 HD wallets, first include the hdkey submodule:

var hdkey = require('ethereumjs-wallet/hdkey')

Constructors:

• fromMasterSeed(seed) - create an instance based on a seed
• fromExtendedKey(key) - create an instance based on a BIP32 extended private or public key

For the seed we suggest to use bip39 to create one from a BIP39 mnemonic.

Instance methods:

• privateExtendedKey() - return a BIP32 extended private key (xprv)
• publicExtendedKey() - return a BIP32 extended public key (xpub)
• derivePath(path) - derive a node based on a path (e.g. m/44'/0'/0/1)
• deriveChild(index) - derive a node based on a child index
• getWallet() - return a Wallet instance as seen above

Provider Engine

The Wallet can be easily plugged into provider-engine to provide signing:

const WalletSubprovider = require('ethereumjs-wallet/provider-engine')

<engine>.addProvider(new WalletSubprovider(<wallet instance>))

Note it only supports the basic wallet. With a HD Wallet, call getWallet() first.

Remarks about toV3

The options is an optional object hash, where all the serialization parameters can be fine tuned:

• uuid - UUID. One is randomly generated.
• salt - Random salt for the kdf. Size must match the requirements of the KDF (key derivation function). Random number generated via crypto.getRandomBytes if nothing is supplied.
• iv - Initialization vector for the cipher. Size must match the requirements of the cipher. Random number generated via crypto.getRandomBytes if nothing is supplied.
• kdf - The key derivation function, see below.
• dklen - Derived key length. For certain cipher settings, this must match the block sizes of those.
• cipher - The cipher to use. Names must match those of supported by OpenSSL, e.g. aes-128-ctr or aes-128-cbc.

Depending on the kdf selected, the following options are available too.

For pbkdf2:

• c - Number of iterations. Defaults to 262144.
• prf - The only supported (and default) value is hmac-sha256. So no point changing it.

For scrypt:

• n - Iteration count. Defaults to 262144.
• r - Block size for the underlying hash. Defaults to 8.
• p - Parallelization factor. Defaults to 1.

The following settings are favoured by the Go Ethereum implementation and we default to the same:

• kdf: scrypt
• dklen: 32
• n: 262144
• r: 8
• p: 1
• cipher: aes-128-ctr

EthereumJS

See our organizational documentation for an introduction to EthereumJS as well as information on current standards and best practices.

If you want to join for work or do improvements on the libraries have a look at our contribution guidelines.

License

MIT License

Copyright (C) 2016 Alex Beregszaszi