Awesome
ethereum-cryptography
Audited pure JS library containing all Ethereum-related cryptographic primitives.
Included algorithms, implemented with just 5 noble & scure dependencies:
- Hashes: SHA256, keccak-256, RIPEMD160, BLAKE2b
- KDFs: PBKDF2, Scrypt
- CSPRNG (Cryptographically Secure Pseudorandom Number Generator)
- secp256k1 elliptic curve
- BIP32 HD Keygen
- BIP39 Mnemonic phrases
- AES Encryption
April 2023 update: v2.0 is out, switching
noble-secp256k1 to
noble-curves,
which changes re-exported api of secp256k1
submodule.
There have been no other changes.
January 2022 update: v1.0 has been released. We've rewritten the library from scratch and audited it. It became 6x smaller: ~5,000 lines of code instead of ~24,000 (with all deps); 650KB instead of 10.2MB. 5 dependencies by 1 author are now used, instead of 38 by 5 authors.
Check out Upgrading section and an article about the library: A safer, smaller, and faster Ethereum cryptography stack.
Usage
Use NPM / Yarn in node.js / browser:
# NPM
npm install ethereum-cryptography
# Yarn
yarn add ethereum-cryptography
See browser usage for information on using the package with major Javascript bundlers. It is tested with Webpack, Rollup, Parcel and Browserify.
This package has no single entry-point, but submodule for each cryptographic primitive. Read each primitive's section of this document to learn how to use them.
The reason for this is that importing everything from a single file will lead to huge bundles when using this package for the web. This could be avoided through tree-shaking, but the possibility of it not working properly on one of the supported bundlers is too high.
// Hashes
import { sha256 } from "ethereum-cryptography/sha256.js";
import { keccak256 } from "ethereum-cryptography/keccak.js";
import { ripemd160 } from "ethereum-cryptography/ripemd160.js";
import { blake2b } from "ethereum-cryptography/blake2b.js";
// KDFs
import { pbkdf2Sync } from "ethereum-cryptography/pbkdf2.js";
import { scryptSync } from "ethereum-cryptography/scrypt.js";
// Random
import { getRandomBytesSync } from "ethereum-cryptography/random.js";
// AES encryption
import { encrypt } from "ethereum-cryptography/aes.js";
// secp256k1 elliptic curve operations
import { secp256k1 } from "ethereum-cryptography/secp256k1.js";
// BIP32 HD Keygen, BIP39 Mnemonic Phrases
import { HDKey } from "ethereum-cryptography/hdkey.js";
import { generateMnemonic } from "ethereum-cryptography/bip39/index.js";
import { wordlist } from "ethereum-cryptography/bip39/wordlists/english.js";
// utilities
import { hexToBytes, toHex, utf8ToBytes } from "ethereum-cryptography/utils.js";
Hashes: SHA256, keccak-256, RIPEMD160, BLAKE2b
function sha256(msg: Uint8Array): Uint8Array;
function sha512(msg: Uint8Array): Uint8Array;
function keccak256(msg: Uint8Array): Uint8Array;
function ripemd160(msg: Uint8Array): Uint8Array;
function blake2b(msg: Uint8Array, outputLength = 64): Uint8Array;
Exposes following cryptographic hash functions:
- SHA2 (SHA256, SHA512)
- keccak-256 variant of SHA3 (also
keccak224
,keccak384
, andkeccak512
) - RIPEMD160
- BLAKE2b
import { sha256 } from "ethereum-cryptography/sha256.js";
import { sha512 } from "ethereum-cryptography/sha512.js";
import { keccak256, keccak224, keccak384, keccak512 } from "ethereum-cryptography/keccak.js";
import { ripemd160 } from "ethereum-cryptography/ripemd160.js";
import { blake2b } from "ethereum-cryptography/blake2b.js";
sha256(Uint8Array.from([1, 2, 3]))
// Can be used with strings
import { utf8ToBytes } from "ethereum-cryptography/utils.js";
sha256(utf8ToBytes("abc"))
// If you need hex
import { bytesToHex as toHex } from "ethereum-cryptography/utils.js";
toHex(sha256(utf8ToBytes("abc")))
KDFs: PBKDF2, Scrypt
function pbkdf2(password: Uint8Array, salt: Uint8Array, iterations: number, keylen: number, digest: string): Promise<Uint8Array>;
function pbkdf2Sync(password: Uint8Array, salt: Uint8Array, iterations: number, keylen: number, digest: string): Uint8Array;
function scrypt(password: Uint8Array, salt: Uint8Array, N: number, p: number, r: number, dkLen: number, onProgress?: (progress: number) => void): Promise<Uint8Array>;
function scryptSync(password: Uint8Array, salt: Uint8Array, N: number, p: number, r: number, dkLen: number, onProgress?: (progress: number) => void)): Uint8Array;
The pbkdf2
submodule has two functions implementing the PBKDF2 key
derivation algorithm in synchronous and asynchronous ways. This algorithm is
very slow, and using the synchronous version in the browser is not recommended,
as it will block its main thread and hang your UI. The KDF supports sha256
and sha512
digests.
The scrypt
submodule has two functions implementing the Scrypt key
derivation algorithm in synchronous and asynchronous ways. This algorithm is
very slow, and using the synchronous version in the browser is not recommended,
as it will block its main thread and hang your UI.
Encoding passwords is a frequent source of errors. Please read these notes before using these submodules.
import { pbkdf2 } from "ethereum-cryptography/pbkdf2.js";
import { utf8ToBytes } from "ethereum-cryptography/utils.js";
// Pass Uint8Array, or convert strings to Uint8Array
console.log(await pbkdf2(utf8ToBytes("password"), utf8ToBytes("salt"), 131072, 32, "sha256"));
import { scrypt } from "ethereum-cryptography/scrypt.js";
import { utf8ToBytes } from "ethereum-cryptography/utils.js";
console.log(await scrypt(utf8ToBytes("password"), utf8ToBytes("salt"), 262144, 8, 1, 32));
CSPRNG (Cryptographically strong pseudorandom number generator)
function getRandomBytes(bytes: number): Promise<Uint8Array>;
function getRandomBytesSync(bytes: number): Uint8Array;
The random
submodule has functions to generate cryptographically strong
pseudo-random data in synchronous and asynchronous ways.
Backed by crypto.getRandomValues
in browser and by crypto.randomBytes
in node.js. If backends are somehow not available, the module would throw an error and won't work, as keeping them working would be insecure.
import { getRandomBytesSync } from "ethereum-cryptography/random.js";
console.log(getRandomBytesSync(32));
secp256k1 curve
function getPublicKey(privateKey: Uint8Array, isCompressed = true): Uint8Array;
function sign(msgHash: Uint8Array, privateKey: Uint8Array): { r: bigint; s: bigint; recovery: number };
function verify(signature: Uint8Array, msgHash: Uint8Array, publicKey: Uint8Array): boolean
function getSharedSecret(privateKeyA: Uint8Array, publicKeyB: Uint8Array): Uint8Array;
function utils.randomPrivateKey(): Uint8Array;
The secp256k1
submodule provides a library for elliptic curve operations on
the curve secp256k1. For detailed documentation, follow README of noble-curves
, which the module uses as a backend.
secp256k1 private keys need to be cryptographically secure random numbers with
certain characteristics. If this is not the case, the security of secp256k1 is
compromised. We strongly recommend using utils.randomPrivateKey()
to generate them.
import { secp256k1 } from "ethereum-cryptography/secp256k1.js";
(async () => {
// You pass either a hex string, or Uint8Array
const privateKey = "6b911fd37cdf5c81d4c0adb1ab7fa822ed253ab0ad9aa18d77257c88b29b718e";
const messageHash = "a33321f98e4ff1c283c76998f14f57447545d339b3db534c6d886decb4209f28";
const publicKey = secp256k1.getPublicKey(privateKey);
const signature = secp256k1.sign(messageHash, privateKey);
const isSigned = secp256k1.verify(signature, messageHash, publicKey);
})();
We're also providing a compatibility layer for users who want to upgrade
from tiny-secp256k1
or secp256k1
modules without hassle.
Check out secp256k1 compatibility layer.
BIP32 HD Keygen
Hierarchical deterministic (HD) wallets that conform to BIP32 standard. Also available as standalone package scure-bip32.
This module exports a single class HDKey
, which should be used like this:
import { HDKey } from "ethereum-cryptography/hdkey.js";
const hdkey1 = HDKey.fromMasterSeed(seed);
const hdkey2 = HDKey.fromExtendedKey(base58key);
const hdkey3 = HDKey.fromJSON({ xpriv: string });
// props
[hdkey1.depth, hdkey1.index, hdkey1.chainCode];
console.log(hdkey2.privateKey, hdkey2.publicKey);
console.log(hdkey3.derive("m/0/2147483647'/1"));
const sig = hdkey3.sign(hash);
hdkey3.verify(hash, sig);
Note: chainCode
property is essentially a private part
of a secret "master" key, it should be guarded from unauthorized access.
The full API is:
class HDKey {
public static HARDENED_OFFSET: number;
public static fromMasterSeed(seed: Uint8Array, versions: Versions): HDKey;
public static fromExtendedKey(base58key: string, versions: Versions): HDKey;
public static fromJSON(json: { xpriv: string }): HDKey;
readonly versions: Versions;
readonly depth: number = 0;
readonly index: number = 0;
readonly chainCode: Uint8Array | null = null;
readonly parentFingerprint: number = 0;
get fingerprint(): number;
get identifier(): Uint8Array | undefined;
get pubKeyHash(): Uint8Array | undefined;
get privateKey(): Uint8Array | null;
get publicKey(): Uint8Array | null;
get privateExtendedKey(): string;
get publicExtendedKey(): string;
derive(path: string): HDKey;
deriveChild(index: number): HDKey;
sign(hash: Uint8Array): Uint8Array;
verify(hash: Uint8Array, signature: Uint8Array): boolean;
wipePrivateData(): this;
}
interface Versions {
private: number;
public: number;
}
The hdkey
submodule provides a library for keys derivation according to
BIP32.
It has almost the exact same API than the version 1.x
of
hdkey
from cryptocoinjs,
but it's backed by this package's primitives, and has built-in TypeScript types.
Its only difference is that it has to be used with a named import.
The implementation is loosely based on hdkey, which has MIT License.
BIP39 Mnemonic Seed Phrase
function generateMnemonic(wordlist: string[], strength: number = 128): string;
function mnemonicToEntropy(mnemonic: string, wordlist: string[]): Uint8Array;
function entropyToMnemonic(entropy: Uint8Array, wordlist: string[]): string;
function validateMnemonic(mnemonic: string, wordlist: string[]): boolean;
async function mnemonicToSeed(mnemonic: string, passphrase: string = ""): Promise<Uint8Array>;
function mnemonicToSeedSync(mnemonic: string, passphrase: string = ""): Uint8Array;
The bip39
submodule provides functions to generate, validate and use seed
recovery phrases according to BIP39.
Also available as standalone package scure-bip39.
import { generateMnemonic } from "ethereum-cryptography/bip39/index.js";
import { wordlist } from "ethereum-cryptography/bip39/wordlists/english.js";
console.log(generateMnemonic(wordlist));
This submodule also contains the word lists defined by BIP39 for Czech, English, French, Italian, Japanese, Korean, Simplified and Traditional Chinese, and Spanish. These are not imported by default, as that would increase bundle sizes too much. Instead, you should import and use them explicitly.
The word lists are exported as a wordlist
variable in each of these submodules:
ethereum-cryptography/bip39/wordlists/czech.js
ethereum-cryptography/bip39/wordlists/english.js
ethereum-cryptography/bip39/wordlists/french.js
ethereum-cryptography/bip39/wordlists/italian.js
ethereum-cryptography/bip39/wordlists/japanese.js
ethereum-cryptography/bip39/wordlists/korean.js
ethereum-cryptography/bip39/wordlists/portuguese.js
ethereum-cryptography/bip39/wordlists/simplified-chinese.js
ethereum-cryptography/bip39/wordlists/spanish.js
ethereum-cryptography/bip39/wordlists/traditional-chinese.js
AES Encryption
function encrypt(msg: Uint8Array, key: Uint8Array, iv: Uint8Array, mode = "aes-128-ctr", pkcs7PaddingEnabled = true): Promise<Uint8Array>;
function decrypt(cypherText: Uint8Array, key: Uint8Array, iv: Uint8Array, mode = "aes-128-ctr", pkcs7PaddingEnabled = true): Promise<Uint8Array>;
The aes
submodule contains encryption and decryption functions implementing
the Advanced Encryption Standard
algorithm.
Encrypting with passwords
AES is not supposed to be used directly with a password. Doing that will compromise your users' security.
The key
parameters in this submodule are meant to be strong cryptographic
keys. If you want to obtain such a key from a password, please use a
key derivation function
like pbkdf2 or scrypt.
Operation modes
This submodule works with different block cipher modes of operation. If you are using this module in a new application, we recommend using the default.
While this module may work with any mode supported by OpenSSL, we only test it
with aes-128-ctr
, aes-128-cbc
, and aes-256-cbc
. If you use another module
a warning will be printed in the console.
We only recommend using aes-128-cbc
and aes-256-cbc
to decrypt already
encrypted data.
Padding plaintext messages
Some operation modes require the plaintext message to be a multiple of 16
. If
that isn't the case, your message has to be padded.
By default, this module automatically pads your messages according to PKCS#7. Note that this padding scheme always adds at least 1 byte of padding. If you are unsure what anything of this means, we strongly recommend you to use the defaults.
If you need to encrypt without padding or want to use another padding scheme,
you can disable PKCS#7 padding by passing false
as the last argument and
handling padding yourself. Note that if you do this and your operation mode
requires padding, encrypt
will throw if your plaintext message isn't a
multiple of 16
.
This option is only present to enable the decryption of already encrypted data. To encrypt new data, we recommend using the default.
How to use the IV parameter
The iv
parameter of the encrypt
function must be unique, or the security
of the encryption algorithm can be compromised.
You can generate a new iv
using the random
module.
Note that to decrypt a value, you have to provide the same iv
used to encrypt
it.
How to handle errors with this module
Sensitive information can be leaked via error messages when using this module. To avoid this, you should make sure that the errors you return don't contain the exact reason for the error. Instead, errors must report general encryption/decryption failures.
Note that implementing this can mean catching all errors that can be thrown when calling on of this module's functions, and just throwing a new generic exception.
Example usage
import { encrypt } from "ethereum-cryptography/aes.js";
import { hexToBytes, utf8ToBytes } from "ethereum-cryptography/utils.js";
console.log(
encrypt(
utf8ToBytes("message"),
hexToBytes("2b7e151628aed2a6abf7158809cf4f3c"),
hexToBytes("f0f1f2f3f4f5f6f7f8f9fafbfcfdfeff")
)
);
Browser usage
Rollup setup
Using this library with Rollup requires the following plugins:
These can be used by setting your plugins
array like this:
plugins: [
commonjs(),
resolve({
browser: true,
preferBuiltins: false,
}),
]
Legacy secp256k1 compatibility layer
Warning: use secp256k1
instead. This module is only for users who upgraded
from ethereum-cryptography v0.1. It could be removed in the future.
The API of secp256k1-compat
is the same as secp256k1-node:
import { createPrivateKeySync, ecdsaSign } from "ethereum-cryptography/secp256k1-compat";
const msgHash = Uint8Array.from(
"82ff40c0a986c6a5cfad4ddf4c3aa6996f1a7837f9c398e17e5de5cbd5a12b28",
"hex"
);
const privateKey = createPrivateKeySync();
console.log(Uint8Array.from(ecdsaSign(msgHash, privateKey).signature));
Missing cryptographic primitives
This package intentionally excludes the cryptographic primitives necessary to implement the following EIPs:
- EIP 196: Precompiled contracts for addition and scalar multiplication on the elliptic curve alt_bn128
- EIP 197: Precompiled contracts for optimal ate pairing check on the elliptic curve alt_bn128
- EIP 198: Big integer modular exponentiation
- EIP 152: Add Blake2 compression function
F
precompile
Feel free to open an issue if you want this decision to be reconsidered, or if you found another primitive that is missing.
Upgrading
Upgrading from 1.0 to 2.0:
secp256k1
module was changed massively: before, it was using noble-secp256k1 1.7; now it uses safer noble-curves. Please refer to upgrading section from curves README. Main changes to keep in mind: a)sign
now returnsSignature
instance b)recoverPublicKey
got moved onto aSignature
instance- node.js 14 and older support was dropped. Upgrade to node.js 16 or later.
Upgrading from 0.1 to 1.0: Same functionality, all old APIs remain the same except for the breaking changes:
- We return
Uint8Array
from all methods that worked withBuffer
before.Buffer
has never been supported in browsers, whileUint8Array
s are supported natively in both browsers and node.js. - We target runtimes with bigint support,
which is Chrome 67+, Edge 79+, Firefox 68+, Safari 14+, node.js 10+. If you need to support older runtimes, use
ethereum-cryptography@0.1
- If you've used
secp256k1
, rename it tosecp256k1-compat
import { sha256 } from "ethereum-cryptography/sha256.js";
// Old usage
const hasho = sha256(Buffer.from("string", "utf8")).toString("hex");
// New usage
import { toHex } from "ethereum-cryptography/utils.js";
const hashn = toHex(sha256("string"));
// If you have `Buffer` module and want to preserve it:
const hashb = Buffer.from(sha256("string"));
const hashbo = hashb.toString("hex");
Security
Audited by Cure53 on Jan 5, 2022. Check out the audit PDF & URL.
License
ethereum-cryptography
is released under The MIT License (MIT)
Copyright (c) 2021 Patricio Palladino, Paul Miller, ethereum-cryptography contributors
See LICENSE file.
hdkey
is loosely based on hdkey,
which had MIT License
Copyright (c) 2018 cryptocoinjs