bitcoinjs-lib/test/integration/crypto.js
2018-07-11 17:22:03 +10:00

110 lines
4.4 KiB
JavaScript

/* global describe, it */
const assert = require('assert')
const BN = require('bn.js')
const bitcoin = require('../../')
const bip32 = require('bip32')
const crypto = require('crypto')
const tinysecp = require('tiny-secp256k1')
const ecurve = require('ecurve')
const secp256k1 = ecurve.getCurveByName('secp256k1')
describe('bitcoinjs-lib (crypto)', function () {
it('can recover a private key from duplicate R values', function () {
this.timeout(30000)
// https://blockchain.info/tx/f4c16475f2a6e9c602e4a287f9db3040e319eb9ece74761a4b84bc820fbeef50
const tx = bitcoin.Transaction.fromHex('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')
tx.ins.forEach(function (input, vin) {
const { output: prevOutput, pubkey, signature } = bitcoin.payments.p2pkh({ input: input.script })
const scriptSignature = bitcoin.script.signature.decode(signature)
const m = tx.hashForSignature(vin, prevOutput, scriptSignature.hashType)
assert(bitcoin.ECPair.fromPublicKey(pubkey).verify(m, scriptSignature.signature), 'Invalid m')
// store the required information
input.signature = scriptSignature.signature
input.z = new BN(m)
})
// finally, run the tasks, then on to the math
const n = new BN(secp256k1.n.toString())
for (var i = 0; i < tx.ins.length; ++i) {
for (var j = i + 1; j < tx.ins.length; ++j) {
const inputA = tx.ins[i]
const inputB = tx.ins[j]
// enforce matching r values
const r = inputA.signature.slice(0, 32)
const rB = inputB.signature.slice(0, 32)
assert.strictEqual(r.toString('hex'), rB.toString('hex'))
const rInv = new BN(r).invm(n)
const s1 = new BN(inputA.signature.slice(32, 64))
const s2 = new BN(inputB.signature.slice(32, 64))
const z1 = inputA.z
const z2 = inputB.z
const zz = z1.sub(z2).mod(n)
const ss = s1.sub(s2).mod(n)
// k = (z1 - z2) / (s1 - s2)
// d1 = (s1 * k - z1) / r
// d2 = (s2 * k - z2) / r
const k = zz.mul(ss.invm(n)).mod(n)
const d1 = ((s1.mul(k).mod(n)).sub(z1).mod(n)).mul(rInv).mod(n)
const d2 = ((s2.mul(k).mod(n)).sub(z2).mod(n)).mul(rInv).mod(n)
// enforce matching private keys
assert.strictEqual(d1.toString(), d2.toString())
}
}
})
it('can recover a BIP32 parent private key from the parent public key, and a derived, non-hardened child private key', function () {
function recoverParent (master, child) {
assert(master.isNeutered(), 'You already have the parent private key')
assert(!child.isNeutered(), 'Missing child private key')
const serQP = master.publicKey
const d1 = child.privateKey
const data = Buffer.alloc(37)
serQP.copy(data, 0)
// search index space until we find it
let d2
for (var i = 0; i < 0x80000000; ++i) {
data.writeUInt32BE(i, 33)
// calculate I
const I = crypto.createHmac('sha512', master.chainCode).update(data).digest()
const IL = I.slice(0, 32)
// See bip32.js:273 to understand
d2 = tinysecp.privateSub(d1, IL)
const Qp = bip32.fromPrivateKey(d2, Buffer.alloc(32, 0)).publicKey
if (Qp.equals(serQP)) break
}
const node = bip32.fromPrivateKey(d2, master.chainCode, master.network)
node.depth = master.depth
node.index = master.index
node.masterFingerprint = master.masterFingerprint
return node
}
const seed = crypto.randomBytes(32)
const master = bip32.fromSeed(seed)
const child = master.derive(6) // m/6
// now for the recovery
const neuteredMaster = master.neutered()
const recovered = recoverParent(neuteredMaster, child)
assert.strictEqual(recovered.toBase58(), master.toBase58())
})
})