ecdsa

JavaScript component for Elliptical Curve Cryptography signing and verification. This package is important to sign transactions. Works with both Node.js and the browser.

Package Info

• github: https://github.com/cryptocoinjs/ecdsa
• tests: https://github.com/cryptocoinjs/ecdsa/tree/master/test
• issues: https://github.com/cryptocoinjs/ecdsa/issues
• license: MIT

Usage

Installation

npm install --save ecdsa

Example

var crypto = require('crypto') //Node.js or Browserify (browser)

var ecdsa = require('ecdsa')
var sr = require('secure-random') //npm install --save secure-random@1.x
var CoinKey = require('coinkey') //npm install --save coinkey@0.1.0

var privateKey = sr.randomBuffer(32)
var ck = new CoinKey(privateKey, true) // true => compressed public key / addresses

var msg = new Buffer("hello world!", 'utf8')
var shaMsg = crypto.createHash('sha256').update(msg).digest()
var signature = ecdsa.sign(shaMsg, ck.privateKey)
var isValid = ecdsa.verify(shaMsg, signature, ck.publicKey)
console.log(isValid) //true

you could also use another curve, you'd probably never need to do this though:

//curves defined here: https://github.com/cryptocoinjs/ecurve/blob/master/lib/names.js
var ecdsa = require('ecdsa')('secp160r1')

API

calcPubKeyRecoveryParam

(TODO)

deterministicGenerateK(hash, privateKey)

Used by sign() to securely and deterministically generate the K value. From RFC 6979.

• hash: Hash that is to be signed
• privateKey: The BigInteger representation of the private key

parseSig(buffer)

Parses the signature and returns an object with r and s values.

• buffer: Is the DER encoded signature as type Buffer.

parseSigCompact(buffer)

(TODO)

recoverPubKey(e, signature, i)

(TODO)

serializeSig(signature)

Serializes a signature object that contains r and s fields into a DER encoded signature with type Buffer.

• signature: signature object. Needs fields r and s.

serializeSigCompact(signature, i ,compressed)

(TODO)

sign(hash, privateKey)

Signs a hash. Typically used to sign crypto currency transactions.

• hash: hash to sign. Type Buffer.
• privateKey: private key to sign with. Type Buffer.

verify(hash, signature, publicKey)

Verifies that the hash is signed with the signature.

(TODO: add params)

verifyRaw(e, signature, Q)

(TODO)