ecpair

A library for managing SECP256k1 keypairs written in TypeScript with transpiled JavaScript committed to git.

Note ECPair.makeRandom() uses the crypto.getRandomValues if there is no custom rng function provided. This API currently is still an experimental feature as of Node.js 18.19.0. To work around this you can do one of the following:

1. Use a polyfill for crypto.getRandomValues()
2. Use the --experimental-global-webcrypto flag when running node.js.
3. Pass in a custom rng function to generate random values.

Example

TypeScript

import { Signer, SignerAsync, ECPairInterface, ECPairFactory, ECPairAPI, TinySecp256k1Interface } from 'ecpair';
import * as crypto from 'crypto';

// You need to provide the ECC library. The ECC library must implement 
// all the methods of the `TinySecp256k1Interface` interface.
const tinysecp: TinySecp256k1Interface = require('tiny-secp256k1');
const ECPair: ECPairAPI = ECPairFactory(tinysecp);

// You don't need to explicitly write ECPairInterface, but just to show
// that the keyPair implements the interface this example includes it.

// From WIF
const keyPair1: ECPairInterface = ECPair.fromWIF('KynD8ZKdViVo5W82oyxvE18BbG6nZPVQ8Td8hYbwU94RmyUALUik');
// Random private key
const keyPair2 = ECPair.fromPrivateKey(crypto.randomBytes(32));
// OR (uses randombytes library, compatible with browser)
const keyPair3 = ECPair.makeRandom();
// OR use your own custom random buffer generator BE CAREFUL!!!!
const customRandomBufferFunc = (size: number): Buffer => crypto.randomBytes(size);
const keyPair4 = ECPair.makeRandom({ rng: customRandomBufferFunc });
// From pubkey (33 or 65 byte DER format public key)
const keyPair5 = ECPair.fromPublicKey(keyPair1.publicKey);

// Pass a custom network
const network = {}; // Your custom network object here
ECPair.makeRandom({ network });
ECPair.fromPrivateKey(crypto.randomBytes(32), { network });
ECPair.fromPublicKey(keyPair1.publicKey, { network });
// fromWIF will check the WIF version against the network you pass in
// pass in multiple networks if you are not sure
ECPair.fromWIF('wif key...', network);
const network2 = {}; // Your custom network object here
const network3 = {}; // Your custom network object here
ECPair.fromWIF('wif key...', [network, network2, network3]);

LICENSE MIT

Written and tested by bitcoinjs-lib contributors since 2014.