Keylink

Derive keys from virtually anything. Navigate through derivation paths like the web!

Expands the BIP32 wallet format to include many additional index types and features.

Features include:

• Specify UTF8 strings as a derivation path!
• Specify hex and hashes as a derivation path!
• Hardening support for all path types!
• More to come!

How to Install

Using the browser:

<script src="https://unpkg.com/@cmdcode/keylink">

Using nodejs:

// Using CommonJS imports.
const KeyLink = require('@cmdcode/keylink')
// Using ES6 imports.
import KeyLink from '@cmdcode/keylink'

How to Use

You can import and export links in a variety of ways.

/* List of Import methods. */
KeyLink
  .fromSeed()       // Create a new chain from a raw seed phrase.
  .fromBase58()     // Import a link from standard base58 format.
  .fromPrivateKey() // Import a link from private key and chaincode.
  .fromPublicKey()  // Import a link from public key and chaincode.

/* List of Export methods. */
KeyLink
  .copy()            // Export a a duplicate copy of current link.
  .export()          // Export a JSON object of the current link.
  .toPublic()        // Export a public (non-signing) copy of current link.
  .toWIF()           // Export as Wallet Import Format for Bitcoin Core.
  .toBase58()        // Export as standard base58check format.

/* Create a link by providing a chaincode and
 * the matching private key or public key.
 */
const link = new KeyLink(  
  seckey ?: Uint8Array  // Private Key.
  pubkey ?: Uint8Array  // Public Key.
  code    : Uint8Array  // Chaincode paired with the key.
  format ?: string      // The format version of the key.
  depth  ?: number      // The depth of this link (max 255).
  index  ?: number      // Index value of the provided key.
  label  ?: string      // Hash label of the provided key.
  marker ?: number      // Checksum marker from parent key.
)

// BIP44 paths still behave like normal.
link.getPath("m/44'/0'/0'/0/1") => new KeyLink

// The API has been simplified for better usage and
// understanding of hardened / non-hardened key spaces.
link.getSecIndex(index : number) => new KeyLink
link.getPubIndex(index : number) => new KeyLink

// You can now specify any length character string,
// and it will be parsed as Uint8Array bytes.
link.getPath("0'/thisisatotallyvalidpath/0/1")

// Hardening also works on strings.
link.getPath("0'/thispathwillbehardened'/0/1")

// If you want to parse a string as a hex-encoded
// value, you can prepend it with a hashtag character.
link.getPath("m/84/#aabbccddeeff00112233445566778899'/0/1")

// This feature takes advantage of a new API format
// that allows passing strings and hex for key derivation.
link.getSecLabel (data : string) => new KeyLink
link.getPubLabel (data : string) => new KeyLink
link.getSecHash  (data : string | Uint8Array) => new KeyLink
link.getPubHash  (data : string | Uint8Array) => new KeyLink

// Full Path derivation API:
link
  .getSecIndex()
  .getPubIndex()
  .getSecHash()
  .getPubHash()
  .getSecLabel()
  .getPubLabel()
  .getPath()

// Additional API:
link
  .chaincode => Uint8Array  // The link chaincode.
  .index     => string      // The current index (formatted).
  .depth     => number      // The current link depth.
  .marker    => number      // The parent marker (fingerprint).
  .label     => string      // The current key label (if any).

Testing

Don't trust, verify!

All BIP32 specified test vectors should pass. Currently in the progress of adding custom vectors for the new derivation types.

All cryptography is done using a fork of the @noble-secp256k1 library, plus the standard WebCrypto API.

If you have a question or run into any issues, please feel free to open a ticket on the issues page!

Contributions

All contributions are welcome!

Resources

BIP32 Wiki Page
https://github.com/bitcoin/bips/blob/master/bip-0032.mediawiki

BIP44 Wiki Page
https://github.com/bitcoin/bips/blob/master/bip-0044.mediawiki

Buff-Utils
https://github.com/cmdruid/buff-utils

Crypto-Utils
https://github.com/cmdruid/crypto-utils