The libp2p crypto primitives, for Node.js and the Browser!
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README.md

js-libp2p-crypto

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Crypto primitives for libp2p in JavaScript

This repo contains the JavaScript implementation of the crypto primitives needed for libp2p. This is based on this go implementation.

Lead Maintainer

Friedel Ziegelmayer

Table of Contents

Install

npm install --save libp2p-crypto

API

crypto.aes

Expoes an interface to AES encryption (formerly Rijndael), as defined in U.S. Federal Information Processing Standards Publication 197.

This uses CTR mode.

crypto.aes.create(key, iv, callback)

  • key: Buffer The key, if length 16 then AES 128 is used. For length 32, AES 256 is used.
  • iv: Buffer Must have length 16.
  • callback: Function
decrypt(data, callback)
  • data: Buffer
  • callback: Function
encrypt(data, callback)
  • data: Buffer
  • callback: Function
var crypto = require('libp2p-crypto')

// Setting up Key and IV

// A 16 bytes array, 128 Bits, AES-128 is chosen
var key128 = Buffer.from([0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15])

// A 16 bytes array, 128 Bits,
var IV = Buffer.from([0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15])

async function main () {
  let decryptedMessage = 'Hello, world!'
  let encryptedMessage

  // Encrypting
  await crypto.aes.create(key128, IV, (err, cipher) => {
    if (!err) {
      cipher.encrypt(Buffer.from(decryptedMessage), (err, encryptedBuffer) => {
        if (!err) {
          console.log(encryptedBuffer)
          // prints: <Buffer 42 f1 67 d9 2e 42 d0 32 9e b1 f8 3c>
          encryptedMessage = encryptedBuffer
        }
      })
    }
  })

  // Decrypting
  await crypto.aes.create(key128, IV, (err, cipher) => {
    if (!err) {
      cipher.decrypt(encryptedMessage, (err, decryptedBuffer) => {
        if (!err) {
          console.log(decryptedBuffer)
          // prints: <Buffer 42 f1 67 d9 2e 42 d0 32 9e b1 f8 3c>
          
          console.log(decryptedBuffer.toString('utf-8'))
          // prints: Hello, world!
        }
      })
    }
  })
}
main()

crypto.hmac

Exposes an interface to the Keyed-Hash Message Authentication Code (HMAC) as defined in U.S. Federal Information Processing Standards Publication 198. An HMAC is a cryptographic hash that uses a key to sign a message. The receiver verifies the hash by recomputing it using the same key.

crypto.hmac.create(hash, secret, callback)

  • hash: String
  • secret: Buffer
  • callback: Function
digest(data, callback)
  • data: Buffer
  • callback: Function

Example:

var crypto = require('libp2p-crypto')

let hash = 'SHA1' // 'SHA256' || 'SHA512'

crypto.hmac.create(hash, Buffer.from('secret'), (err, hmac) => {
  if (!err) {
    hmac.digest(Buffer.from('hello world'), (err, sig) => {
      if (!err) {
        console.log(sig)
      }
    })
  }
})

crypto.keys

Supported Key Types

The generateKeyPair, marshalPublicKey, and marshalPrivateKey functions accept a string type argument.

Currently the 'RSA' and 'ed25519' types are supported, although ed25519 keys support only signing and verification of messages. For encryption / decryption support, RSA keys should be used.

Installing the libp2p-crypto-secp256k1 module adds support for the 'secp256k1' type, which supports ECDSA signatures using the secp256k1 elliptic curve popularized by Bitcoin. This module is not installed by default, and should be explicitly depended on if your project requires secp256k1 support.

crypto.keys.generateKeyPair(type, bits, callback)

Generates a keypair of the given type and bitsize.

crypto.keys.generateEphemeralKeyPair(curve, callback)

  • curve: String, one of 'P-256', 'P-384', 'P-521' is currently supported
  • callback: Function

Generates an ephemeral public key and returns a function that will compute the shared secret key.

Focuses only on ECDH now, but can be made more general in the future.

Calls back with an object of the form

{
  key: Buffer,
  genSharedKey: Function
}

crypto.keys.keyStretcher(cipherType, hashType, secret, callback)

  • cipherType: String, one of 'AES-128', 'AES-256', 'Blowfish'
  • hashType: String, one of 'SHA1', SHA256, SHA512
  • secret: Buffer
  • callback: Function

Generates a set of keys for each party by stretching the shared key.

Calls back with an object of the form:

{
  k1: {
    iv: Buffer,
    cipherKey: Buffer,
    macKey: Buffer
  },
  k2: {
    iv: Buffer,
    cipherKey: Buffer,
    macKey: Buffer
  }
}

crypto.keys.marshalPublicKey(key[, type], callback)

  • key: keys.rsa.RsaPublicKey | keys.ed25519.Ed25519PublicKey | require('libp2p-crypto-secp256k1').Secp256k1PublicKey
  • type: String, see Supported Key Types above.

Converts a public key object into a protobuf serialized public key.

crypto.keys.unmarshalPublicKey(buf)

  • buf: Buffer

Converts a protobuf serialized public key into its representative object.

crypto.keys.marshalPrivateKey(key[, type])

  • key: keys.rsa.RsaPrivateKey | keys.ed25519.Ed25519PrivateKey | require('libp2p-crypto-secp256k1').Secp256k1PrivateKey
  • type: String, see Supported Key Types above.

Converts a private key object into a protobuf serialized private key.

crypto.keys.unmarshalPrivateKey(buf, callback)

  • buf: Buffer
  • callback: Function

Converts a protobuf serialized private key into its representative object.

crypto.keys.import(pem, password, callback)

  • pem: string
  • password: string
  • callback: Function

Converts a PEM password protected private key into its representative object.

crypto.randomBytes(number)

  • number: Number

Generates a Buffer with length number populated by random bytes.

crypto.pbkdf2(password, salt, iterations, keySize, hash)

  • password: String
  • salt: String
  • iterations: Number
  • keySize: Number in bytes
  • hash: String the hashing algorithm ('sha1', 'sha2-512', ...)

Computes the Password Based Key Derivation Function 2; returning a new password.

Contribute

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

This repository falls under the IPFS Code of Conduct.

License

MIT