js-libp2p-crypto-secp256k1

Support for secp256k1 keys in js-libp2p-crypto

This repo contains a js-libp2p-crypto-compatible implementation of cryptographic signature generation and verification using the secp256k1 elliptic curve popularized by Bitcoin and other crypto currencies.

Lead Captain

Friedel Ziegelmayer

Table of Contents

• Install
• Usage
  • Example
• API
  • generateKeyPair([bits,] callback)
  • unmarshalSecp256k1PublicKey(bytes)
  • unmarshalSecp256k1PrivateKey(bytes, callback)
  • Secp256k1PublicKey
    • .verify(data, sig, callback)
  • Secp256k1PrivateKey
    • .public
    • .sign(data, callback)
• Contribute
• License

Install

npm install --save libp2p-crypto-secp256k1

Usage

This module is designed to work with js-libp2p-crypto.
Installing libp2p-crypto-secp256k1 will automatically add support for the 'secp256k1' key type, which can be used as an argument to the libp2p-crypto API functions generateKeyPair, unmarshalPublicKey, and marshalPrivateKey. The keys returned from those functions will be instances of the Secp256k1PublicKey or Secp256k1PrivateKey classes provided by this module.

Example

const crypto = require('libp2p-crypto')

const msg = Buffer.from('Hello World')

crypto.generateKeyPair('secp256k1', 256, (err, key) => {
  // assuming no error, key will be an instance of Secp256k1PrivateKey
  // the public key is available as key.public
  key.sign(msg, (err, sig) => {
    key.public.verify(msg, sig, (err, valid) => {
      assert(valid, 'Something went horribly wrong')
    })
  })
})

API

The functions below are the public API of this module. For usage within libp2p-crypto, see the libp2p-crypto API documentation.

generateKeyPair([bits, ] callback)

• bits: Number - Optional, included for compatibility with js-libp2p-crypto. Ignored if present; private keys will always be 256 bits.
• callback: Function

unmarshalSecp256k1PublicKey(bytes)

• bytes: Buffer

Converts a serialized secp256k1 public key into an instance of Secp256k1PublicKey and returns it

unmarshalSecp256k1PrivateKey(bytes, callback)

• bytes: Buffer
• callback: Function

Converts a serialized secp256k1 private key into an instance of Secp256k1PrivateKey, passing it to callback on success

Secp256k1PublicKey

.verify(data, sig, callback)

• data: Buffer
• sig: Buffer
• callback: Function

Calculates the SHA-256 hash of data, and verifies the DER-encoded signature in sig, passing the result to callback

Secp256k1PrivateKey

.public

Accessor for the Secp256k1PublicKey associated with this private key.

.sign(data, callback)

• data: Buffer

Calculates the SHA-256 hash of data and signs it, passing the DER-encoded signature to callback

Contribute

Feel free to join in. All welcome. Open an issue!

This repository falls under the IPFS Code of Conduct.

License

MIT