libp2p-crypto-secp256k1

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])
  • unmarshalSecp256k1PublicKey(bytes)
  • unmarshalSecp256k1PrivateKey(bytes)
  • Secp256k1PublicKey
    • .verify(data, sig)
  • Secp256k1PrivateKey
    • .public
    • .sign(data)
• 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')

const key = await crypto.generateKeyPair('secp256k1', 256)
// assuming no error, key will be an instance of Secp256k1PrivateKey
// the public key is available as key.public
const sig = await key.sign(msg)

const valid = await key.public.verify(msg, sig)
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])

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

Returns Promise<Secp256k1PrivateKey>

unmarshalSecp256k1PublicKey(bytes)

• bytes: Buffer

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

unmarshalSecp256k1PrivateKey(bytes)

• bytes: Buffer

Returns Promise<Secp256k1PrivateKey>

Converts a serialized secp256k1 private key into an instance of Secp256k1PrivateKey.

Secp256k1PublicKey

.verify(data, sig)

• data: Buffer
• sig: Buffer

Returns Promise<Boolean>

Calculates the SHA-256 hash of data, and verifies the DER-encoded signature in sig.

Secp256k1PrivateKey

.public

Accessor for the Secp256k1PublicKey associated with this private key.

.sign(data)

• data: Buffer

Returns Promise<Buffer>

Calculates the SHA-256 hash of data and signs it, resolves with the DER-encoded signature.

Contribute

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

This repository falls under the IPFS Code of Conduct.

License

MIT