bitcoinjs-lib/src/message.js
2015-03-19 13:33:28 +11:00

57 lines
1.6 KiB
JavaScript

var bufferutils = require('./bufferutils')
var crypto = require('./crypto')
var ecdsa = require('./ecdsa')
var networks = require('./networks')
var BigInteger = require('bigi')
var ECPair = require('./ecpair')
var ECSignature = require('./ecsignature')
var ecurve = require('ecurve')
var ecparams = ecurve.getCurveByName('secp256k1')
function magicHash (message, network) {
var messagePrefix = new Buffer(network.messagePrefix)
var messageBuffer = new Buffer(message)
var lengthBuffer = bufferutils.varIntBuffer(messageBuffer.length)
var buffer = Buffer.concat([messagePrefix, lengthBuffer, messageBuffer])
return crypto.hash256(buffer)
}
function sign (keyPair, message, network) {
network = network || networks.bitcoin
var hash = magicHash(message, network)
var signature = keyPair.sign(hash)
var e = BigInteger.fromBuffer(hash)
var i = ecdsa.calcPubKeyRecoveryParam(ecparams, e, signature, keyPair.Q)
return signature.toCompact(i, keyPair.compressed)
}
// TODO: network could be implied from address
function verify (address, signature, message, network) {
if (!Buffer.isBuffer(signature)) {
signature = new Buffer(signature, 'base64')
}
network = network || networks.bitcoin
var hash = magicHash(message, network)
var parsed = ECSignature.parseCompact(signature)
var e = BigInteger.fromBuffer(hash)
var Q = ecdsa.recoverPubKey(ecparams, e, parsed.signature, parsed.i)
var keyPair = new ECPair(null, Q, {
compressed: parsed.compressed,
network: network
})
return keyPair.getAddress().toString() === address.toString()
}
module.exports = {
magicHash: magicHash,
sign: sign,
verify: verify
}